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Sample records for azurin-gold nanoparticle hybrid

  1. Long-Range Interfacial Electrochemical Electron Transfer of Pseudomonas aeruginosa Azurin-Gold Nanoparticle Hybrid Systems

    DEFF Research Database (Denmark)

    Jensen, Palle Skovhus; Chi, Qijin; Zhang, Jingdong;

    2009-01-01

    We have prepared a "hybrid" of the blue copper protein azurin (Pseudomonas aeruginosa) and a 3 nm gold nanoparticle (AuNP). The AuNP/azurin hybrid was assembled on a Au(111)-electrode surface in a two-step process. The AuNP was first attached to the Au(111) electrode via Au-S chemisorption of a 4...

  2. Asymmetric Hybrid Nanoparticles

    Energy Technology Data Exchange (ETDEWEB)

    Chumanov, George [Clemson Univ., SC (United States)

    2015-11-05

    Hybrid Nanoparticles (AHNs) are rationally-designed multifunctional nanostructures and novel building blocks for the next generation of advanced materials and devices. Nanoscale materials attract considerable interest because of their unusual properties and potential for practical applications. Most of the activity in this field is focused on the synthesis of homogeneous nanoparticles from metals, metal oxides, semiconductors, and polymers. It is well recognized that properties of nanoparticles can be further enhanced if they are made as hybrid structures. This program is concerned with the synthesis, characterization, and application of such hybrid structures termed AHNs. AHNs are composed of a homogeneous core and several caps of different materials deposited on its surface (Fig. 1). Combined properties of the core and the caps as well as new properties that arise from core-cap and cap-cap interactions render AHNs multifunctional. In addition, specific chemical reactivity of the caps enables directional self-assembly of AHNs into complex architectures that are not possible with only spherical nanoparticles.

  3. Silicon nanocrystal-noble metal hybrid nanoparticles.

    Science.gov (United States)

    Sugimoto, H; Fujii, M; Imakita, K

    2016-06-01

    We report a novel and facile self-limiting synthesis route of silicon nanocrystal (Si NC)-based colloidally stable semiconductor-metal (gold, silver and platinum) hybrid nanoparticles (NPs). For the formation of hybrid NPs, we employ ligand-free colloidal Si NCs with heavily boron (B) and phosphorus (P) doped shells. By simply mixing B and P codoped colloidal Si NCs with metal salts, hybrid NPs consisting of metal cores and Si NC shells are spontaneously formed. We demonstrate the synthesis of highly uniform and size controllable hybrid NPs. It is shown that codoped Si NCs act as a reducing agent for metal salts and also as a protecting layer to stop metal NP growth. The process is thus self-limiting. The development of a variety of Si NC-based hybrid NPs is a promising first step for the design of biocompatible multifunctional NPs with broad material choices for biosensing, bioimaging and solar energy conversion. PMID:27121127

  4. Ionic liquid-nanoparticle hybrid electrolytes

    KAUST Repository

    Lu, Yingying

    2012-01-01

    We investigate physical and electrochemical properties of a family of organic-inorganic hybrid electrolytes based on the ionic liquid 1-methyl-3-propylimidazolium bis(trifluoromethanesulfone) imide covalently tethered to silica nanoparticles (SiO 2-IL-TFSI). The ionic conductivity exhibits a pronounced maximum versus LiTFSI composition, and in mixtures containing 13.4 wt% LiTFSI, the room-temperature ionic conductivity is enhanced by over 3 orders of magnitude relative to either of the mixture components, without compromising lithium transference number. The SiO 2-IL-TFSI/LiTFSI hybrid electrolytes are thermally stable up to 400°C and exhibit tunable mechanical properties and attractive (4.25V) electrochemical stability in the presence of metallic lithium. We explain these observations in terms of ionic coupling between counterion species in the mobile and immobile (particle-tethered) phases of the electrolytes. © 2012 The Royal Society of Chemistry.

  5. Integrated graphene/nanoparticle hybrids for biological and electronic applications

    Science.gov (United States)

    Nguyen, Kim Truc; Zhao, Yanli

    2014-05-01

    The development of novel graphene/nanoparticle hybrid materials is currently the subject of tremendous research interest. The intrinsic exceptional assets of both graphene (including graphene oxide and reduced graphene oxide) and nanoparticles render their hybrid materials synergic properties that can be useful in various applications. In this feature review, we highlight recent developments in graphene/nanoparticle hybrids and their promising potential in electronic and biological applications. First, the latest advances in synthetic methods for the preparation of the graphene/nanoparticle hybrids are introduced, with the emphasis on approaches to (1) decorate nanoparticles onto two-dimensional graphene and (2) wrap nanoparticles with graphene sheets. The pros and cons of large-scale synthesis are also discussed. Then, the state-of-the-art of graphene/nanoparticle hybrids in electronic and biological applications is reviewed. For electronic applications, we focus on the advantages of using these hybrids in transparent conducting films, as well as energy harvesting and storage. Biological applications, electrochemical biosensing, bioimaging, and drug delivery using the hybrids are showcased. Finally, the future research prospects and challenges in this rapidly developing area are discussed.

  6. Near infrared light responsive hybrid nanoparticles for synergistic therapy.

    Science.gov (United States)

    Liang, Yan; Gao, Wenxia; Peng, Xinyu; Deng, Xin; Sun, Changzhen; Wu, Huayue; He, Bin

    2016-09-01

    A near infrared (NIR) light responsive chromophore 7-(diethylamino)-4-(hydroxymethyl)-2H-chromen-2-one (DEACM) was synthesized and incorporated to β-cyclodextrins with cRGD functionalized poly(ethylene glycol), the amphiphiles were coordinated with Au nanorods or nanoparticles to load anticancer drug doxorubicin (DOX) for fabricating hybrid nanoparticles. The π-π stacking interaction between DEACM and DOX was formed in the hybrid nanoparticles, which contributed to the high drug loading content. The Au nanorods or nanoparticles enhanced the photosolvolysis of DEACM under the irradiation of NIR with 808 nm wavelength and triggered the accelerated drug release from the nanoparticles. The drug loaded hybrid nanoparticles with NIR irradiation exhibited efficient inhibition effect on the proliferation of 4T1 breast cancer cells in vitro. The in vivo anticancer activity study on breast cancer bearing mice revealed that the hybrid nanoparticles containing Au nanorods exhibited excellent anticancer activity under the irradiation of 808 nm wavelength NIR with 800 mW. PMID:27244691

  7. In Situ Synthesis of Metal Nanoparticle Embedded Hybrid Soft Nanomaterials.

    Science.gov (United States)

    Divya, Kizhmuri P; Miroshnikov, Mikhail; Dutta, Debjit; Vemula, Praveen Kumar; Ajayan, Pulickel M; John, George

    2016-09-20

    The allure of integrating the tunable properties of soft nanomaterials with the unique optical and electronic properties of metal nanoparticles has led to the development of organic-inorganic hybrid nanomaterials. A promising method for the synthesis of such organic-inorganic hybrid nanomaterials is afforded by the in situ generation of metal nanoparticles within a host organic template. Due to their tunable surface morphology and porosity, soft organic materials such as gels, liquid crystals, and polymers that are derived from various synthetic or natural compounds can act as templates for the synthesis of metal nanoparticles of different shapes and sizes. This method provides stabilization to the metal nanoparticles by the organic soft material and advantageously precludes the use of external reducing or capping agents in many instances. In this Account, we exemplify the green chemistry approach for synthesizing these materials, both in the choice of gelators as soft material frameworks and in the reduction mechanisms that generate the metal nanoparticles. Established herein is the core design principle centered on conceiving multifaceted amphiphilic soft materials that possess the ability to self-assemble and reduce metal ions into nanoparticles. Furthermore, these soft materials stabilize the in situ generated metal nanoparticles and retain their self-assembly ability to generate metal nanoparticle embedded homogeneous organic-inorganic hybrid materials. We discuss a remarkable example of vegetable-based drying oils as host templates for metal ions, resulting in the synthesis of novel hybrid nanomaterials. The synthesis of metal nanoparticles via polymers and self-assembled materials fabricated via cardanol (a bioorganic monomer derived from cashew nut shell liquid) are also explored in this Account. The organic-inorganic hybrid structures were characterized by several techniques such as UV-visible spectroscopy, scanning electron microscopy (SEM), and

  8. Transmission electron microscopy of unstained hybrid Au nanoparticles capped with PPAA (plasma-poly-allylamine)

    DEFF Research Database (Denmark)

    Gontard, Lionel C.; Fernández, Asunción; Dunin-Borkowski, Rafal E.;

    2014-01-01

    Hybrid (organic shell-inorganic core) nanoparticles have important applications in nanomedicine. Although the inorganic components of hybrid nanoparticles can be characterized readily using conventional transmission electron microscopy (TEM) techniques, the structural and chemical arrangement of ...

  9. Nematic-like organization of magnetic mesogen-hybridized nanoparticles.

    Science.gov (United States)

    Demortière, Arnaud; Buathong, Saïwan; Pichon, Benoît P; Panissod, Pierre; Guillon, Daniel; Bégin-Colin, Sylvie; Donnio, Bertrand

    2010-06-21

    A fluid nematic-like phase is induced in monodisperse iron oxide nanoparticles with a diameter of 3.3 nm. This supramolecular arrangement is governed by the covalent functionalization of the nanoparticle surface with cyanobiphenyl-based ligands as mesogenic promoters. The design and synthesis of these hybrid materials and the study of their mesogenic properties are reported. In addition, the modifications of the magnetic properties of the hybridized nanoparticles are investigated as a function of the different grafted ligands. Owing to the rather large interparticular distances (about 7 nm), the dipolar interaction between nanoparticles is shown to play only a minor role. Conversely, the surface magnetic anisotropy of the particles is significantly affected by the surface derivatization. PMID:20486228

  10. Prospects for graphene–nanoparticle-based hybrid sensors

    Science.gov (United States)

    Yin, Perry T.; Kim, Tae-Hyung; Choi, Jeong-Woo; Lee, Ki-Bum

    2014-01-01

    Graphene is a single-atom thick, two-dimensional sheet of carbon that is characterized by exceptional chemical, electrical, material, optical, and physical properties. As a result, graphene and related materials, such as graphene oxide and reduced graphene oxide, have been brought to the forefront in the field of sensing. Recently, a number of reports have demonstrated that graphene–nanoparticle hybrid structures can act synergistically to offer a number of unique physicochemical properties that are desirable and advantageous for sensing applications. These graphene–nanoparticle hybrid structures are particularly interesting because not only do they display the individual properties of the nanoparticles and of graphene, but they can also exhibit additional synergistic properties thereby enhancing the achievable sensitivity and selectivity using a variety of sensing mechanisms. As such, in this perspective, we will discuss the progress that has been made in the development and application of graphene–nanoparticle hybrid sensors and their future prospects. In particular, we will focus on the preparation of graphene–nanoparticle hybrid structures as well as their application in electronic, electrochemical, and optical sensors. PMID:23828095

  11. Versatile Solid Phase Syntheses of Structured Nanoparticle Hybrids

    Science.gov (United States)

    Koberstein, Jeffrey

    2011-03-01

    While it is widely recognized that nanoparticles can exhibit a wide variety of exciting size-dependent properties and responses, it is equally important to recognize that devices and systems cannot be created from bare nanoparticles alone. The potential of nanoparticles can only be achieved by proper consideration of matrices that not only provide mechanical support and integrity to the nanoparticles, but can also control various aspects of their spatial assembly such as geometry and interparticle spacing. Polymers represent a logical and robust matrix for the creation of nanocomposite assemblies, however, phenomena such as aggregation are often problematic when blending nanoparticles and homopolymers. These problems can be avoided by preparation of nanoparticle hybrids wherein all required polymers are covalently tethered to the nanoparticles prior to assembly so that a polymer matrix is not necessary. We report on a new method for covalent decoration of nanoparticles with polymers of tailored molecular design that is based upon a solid phase synthesis strategy. The modular process, much like molecular Tinker Toys, is capable of decorating nanoparticles with essentially any type of branched or copolymeric structure using only a few elementary heterobifunctional building blocks. Because end group functionality is always retained in the process, functional nanoparticles can be readily crosslinked by simple orthogonal reactions such as azide-alkyne click chemistry. The method can be used to create sophisticated hybrid nanoparticle structures important to drug delivery applications, to form highly functional crosslinkers that gel at conversions as low as a few percent, or to fabricate crosslinked matrix-free nanocomposites. Supported by grants DMR-0704054 from the NSF and W911NF-10-1-0184 from the US Army Research Office.

  12. Engineered Hybrid Nanoparticles for On-Demand Diagnostics and Therapeutics.

    Science.gov (United States)

    Nguyen, Kim Truc; Zhao, Yanli

    2015-12-15

    Together with the simultaneous development of nanomaterials and molecular biology, the bionano interface brings about various applications of hybrid nanoparticles in nanomedicine. The hybrid nanoparticles not only present properties of the individual components but also show synergistic effects for specialized applications. Thus, the development of advanced hybrid nanoparticles for targeted and on-demand diagnostics and therapeutics of diseases has rapidly become a hot research topic in nanomedicine. The research focus is to fabricate novel classes of programmable hybrid nanoparticles that are precisely engineered to maximize drug concentrations in diseased cells, leading to enhanced efficacy and reduced side effects of chemotherapy for the disease treatment. In particular, the hybrid nanoparticle platforms can simultaneously target diseased cells, enable the location to be imaged by optical methods, and release therapeutic drugs to the diseased cells by command. This Account specially discusses the rational fabrication of integrated hybrid nanoparticles and their applications in diagnostics and therapeutics. For diagnostics applications, hybrid nanoparticles can be utilized as imaging agents that enable detailed visualization at the molecular level. By the use of suitable targeting ligands incorporated on the nanoparticles, targeted optical imaging may be feasible with improved performance. Novel imaging techniques such as multiphoton excitation and photoacoustic imaging using near-infrared light have been developed using the intrinsic properties of particular nanoparticles. The use of longer-wavelength excitation sources allows deeper penetration into the human body for disease diagnostics and at the same time reduces the adverse effects on normal tissues. Furthermore, multimodal imaging techniques have been achieved by combining several types of components in nanoparticles, offering higher accuracy and better spatial views, with the aim of detecting life

  13. Engineered Hybrid Nanoparticles for On-Demand Diagnostics and Therapeutics.

    Science.gov (United States)

    Nguyen, Kim Truc; Zhao, Yanli

    2015-12-15

    Together with the simultaneous development of nanomaterials and molecular biology, the bionano interface brings about various applications of hybrid nanoparticles in nanomedicine. The hybrid nanoparticles not only present properties of the individual components but also show synergistic effects for specialized applications. Thus, the development of advanced hybrid nanoparticles for targeted and on-demand diagnostics and therapeutics of diseases has rapidly become a hot research topic in nanomedicine. The research focus is to fabricate novel classes of programmable hybrid nanoparticles that are precisely engineered to maximize drug concentrations in diseased cells, leading to enhanced efficacy and reduced side effects of chemotherapy for the disease treatment. In particular, the hybrid nanoparticle platforms can simultaneously target diseased cells, enable the location to be imaged by optical methods, and release therapeutic drugs to the diseased cells by command. This Account specially discusses the rational fabrication of integrated hybrid nanoparticles and their applications in diagnostics and therapeutics. For diagnostics applications, hybrid nanoparticles can be utilized as imaging agents that enable detailed visualization at the molecular level. By the use of suitable targeting ligands incorporated on the nanoparticles, targeted optical imaging may be feasible with improved performance. Novel imaging techniques such as multiphoton excitation and photoacoustic imaging using near-infrared light have been developed using the intrinsic properties of particular nanoparticles. The use of longer-wavelength excitation sources allows deeper penetration into the human body for disease diagnostics and at the same time reduces the adverse effects on normal tissues. Furthermore, multimodal imaging techniques have been achieved by combining several types of components in nanoparticles, offering higher accuracy and better spatial views, with the aim of detecting life

  14. Enhanced Photoluminescence Property for Quantum Dot-Gold Nanoparticle Hybrid

    OpenAIRE

    Huang, Qianqian; Chen, Jing; Zhao, Jian; Pan, Jiangyong; Lei, Wei; Zhang, Zichen

    2015-01-01

    In this paper, we have synthesized ZnCdSeS quantum dots (QDs)-gold nanoparticle (Au NPs) hybrids in aqueous solution via bi-functional linker mercaptoacetic acid (MPA). The absorption peaks of ZnCdSeS QDs and Au are both located at 520 nm. It is investigated that PL intensity of QD-Au hybrid can be affected by the amounts of Au and pH value of hybrid solution. The located surface plasmon resonance (LSPR) effect of QD-Au NPs has been demonstrated by increased fluorescence intensity. The phenom...

  15. Piperidinium tethered nanoparticle-hybrid electrolyte for lithium metal batteries

    KAUST Repository

    Korf, Kevin S.

    2014-06-23

    We report on the synthesis of novel piperidinium-based ionic liquid tethered nanoparticle hybrid electrolytes and investigate their physical and electrochemical properties. Hybrid electrolytes based on the ionic liquid 1-methyl-1-propylpiperidinium bis(trifluoromethanesulfone) imide covalently tethered to silica nanoparticles (SiO2-PP-TFSI) were blended with propylene carbonate-1 M lithium bis(trifluoromethanesulfone) imide (LiTFSI). We employed NMR analysis to confirm the successful creation of the hybrid material. Dielectric and rheological measurements show that these electrolytes exhibit exceptional room-temperature DC ionic conductivity (10-2 to 10 -3 S cm-1) as well as high shear mechanical moduli (105 to 106 Pa). Lithium transference numbers were found to increase with particle loading and to reach values as high as 0.22 at high particle loadings where the particle jam to form a soft glassy elastic medium. Analysis of lithium electrodeposits obtained in the hybrid electrolytes using SEM and EDX spectra show that the SiO2-PP-TFSI nanoparticles are able to smooth lithium deposition and inhibit lithium dendrite proliferation in Li metal batteries. LTOSiO2-PP-TFSI/PC in 1 M LiTFSILi half-cells based on the SiO2-PP-TFSI hybrid electrolytes exhibit attractive voltage profiles and trouble-free extended cycling behavior over more than 1000 cycles of charge and discharge. This journal is © the Partner Organisations 2014.

  16. SERS of semiconducting nanoparticles (TIO{sub 2} hybrid composites).

    Energy Technology Data Exchange (ETDEWEB)

    Rajh, T.; Musumeci, A.; Gosztola, D.; Schiller, T.; Dimitrijevic, N. M.; Mujica, V.; Martin, D.; Center for Nanoscale Materials

    2009-05-06

    Raman scattering of molecules adsorbed on the surface of TiO{sub 2} nanoparticles was investigated. We find strong enhancement of Raman scattering in hybrid composites that exhibit charge transfer absorption with TiO{sub 2} nanoparticles. An enhancement factor up to {approx}10{sup 3} was observed in the solutions containing TiO{sub 2} nanoparticles and biomolecules, including the important class of neurotransmitters such as dopamine and dopac (3,4-dihydroxy-phenylacetic acid). Only selected vibrations are enhanced, indicating molecular specificity due to distinct binding and orientation of the biomolecules coupled to the TiO{sub 2} surface. All enhanced modes are associated with the asymmetric vibrations of attached molecules that lower the symmetry of the charge transfer complex. The intensity and the energy of selected vibrations are dependent on the size and shape of nanoparticle support. Moreover, we show that localization of the charge in quantized nanoparticles (2 nm), demonstrated as the blue shift of particle absorption, diminishes SERS enhancement. Importantly, the smallest concentration of adsorbed molecules shows the largest Raman enhancements suggesting the possibility for high sensitivity of this system in the detection of biomolecules that form a charge transfer complex with metal oxide nanoparticles. The wavelength-dependent properties of a hybrid composite suggest a Raman resonant state. Adsorbed molecules that do not show a charge transfer complex show weak enhancements probably due to the dielectric cavity effect.

  17. Enhanced Photoluminescence Property for Quantum Dot-Gold Nanoparticle Hybrid

    Science.gov (United States)

    Huang, Qianqian; Chen, Jing; Zhao, Jian; Pan, Jiangyong; Lei, Wei; Zhang, Zichen

    2015-10-01

    In this paper, we have synthesized ZnCdSeS quantum dots (QDs)-gold nanoparticle (Au NPs) hybrids in aqueous solution via bi-functional linker mercaptoacetic acid (MPA). The absorption peaks of ZnCdSeS QDs and Au are both located at 520 nm. It is investigated that PL intensity of QD-Au hybrid can be affected by the amounts of Au and pH value of hybrid solution. The located surface plasmon resonance (LSPR) effect of QD-Au NPs has been demonstrated by increased fluorescence intensity. The phenomenon of fluorescence enhancement can be maximized under the optimized pH value of 8.5. LSPR-enhanced photoluminescence property of QD-Au hybrid will be beneficial for the potential applications in the area of biological imaging and detection.

  18. Hybrid plasmonic/semiconductor nanoparticle monolayer assemblies as hyperbolic metamaterials

    DEFF Research Database (Denmark)

    Zhukovsky, Sergei; Ozel, Tuncay; Mutlugun, Evren;

    2014-01-01

    We show that hybrid nanostructures made of alternating colloidal semiconductor quantum dot and metal nanoparticle monolayers can function as multilayer hyperbolic meta-materials. By choosing the thickness of the spacer between the quantum dot and nanoparticle layers, one can achieve the indefinite...... effective permittivity tensor of the structure. This results in increased photonic density of states and strong enhancement of quantum dot luminescence, in line with recent experimental results. Our findings demonstrate that hyperbolic metamaterials can increase the radiative decay rate of emission centers...

  19. Block copolymer-nanoparticle hybrid self-assembly

    KAUST Repository

    Hoheisel, Tobias N.

    2015-01-01

    © 2014 Published by Elsevier Ltd. Polymer-inorganic hybrid materials provide exciting opportunities as they may display favorable properties from both constituents that are desired in applications including catalysis and energy conversion and storage. For the preparation of hybrid materials with well-defined morphologies, block copolymer-directed nanoparticle hybrids present a particularly promising approach. As will be described in this review, once the fundamental characteristics for successful nanostructure formation at or close to the thermodynamic equilibrium of these nanocomposites are identified, the approach can be generalized to various materials classes. In addition to the discussion of recent materials developments based on the use of AB diblock copolymers as well as ABC triblock terpolymers, this review will therefore emphasize progress in the fundamental understanding of the underlying formation mechanisms of such hybrid materials. To this end, critical experiments for, as well as theoretical progress in the description of these nanostructured block copolymer-based hybrid materials will be discussed. Rather than providing a comprehensive overview, the review will emphasize work by the Wiesner group at Cornell University, US, on block copolymer-directed nanoparticle assemblies as well as their use in first potential application areas. The results provide powerful design criteria for wet-chemical synthesis methodologies for the generation of functional nanomaterials for applications ranging from microelectronics to catalysis to energy conversion and storage.

  20. Ionic-Liquid-Tethered Nanoparticles: Hybrid Electrolytes

    KAUST Repository

    Moganty, Surya S.

    2010-10-22

    A new class of solventless electrolytes was created by tethering ionic liquids to hard inorganic ZrO2 nanostructures (see picture; NIM=nanoscale ionic material). These hybrid fluids exhibit exceptional redox stability windows, excellent thermal stability, good lithium transference numbers, long-term interfacial stability in the presence of a lithium anode and, when doped with lithium salt, reasonable ionic conductivities.

  1. Gold nanoparticle-decellularized matrix hybrids for cardiac tissue engineering.

    Science.gov (United States)

    Shevach, Michal; Fleischer, Sharon; Shapira, Assaf; Dvir, Tal

    2014-10-01

    Decellularized matrices are valuable scaffolds for engineering functional cardiac patches for treating myocardial infarction. However, the lack of quick and efficient electrical coupling between adjacent cells may jeopardize the success of the treatment. To address this issue, we have deposited gold nanoparticles on fibrous decellularized omental matrices and investigated their morphology, conductivity, and degradation. We have shown that cardiac cells engineered within the hybrid scaffolds exhibited elongated and aligned morphology, massive striation, and organized connexin 43 electrical coupling proteins. Finally, we have shown that the hybrid patches demonstrated superior function as compared to pristine patches, including a stronger contraction force, lower excitation threshold, and faster calcium transients.

  2. Studying the mechanism of hybrid nanoparticle EUV photoresists

    KAUST Repository

    Zhang, Ben

    2015-03-23

    This work focuses on the investigation of dual tone patterning mechanism with hybrid inorganic/organic photoresists. Hafnium oxide (HfO2) modified with acrylic acid was prepared and the influence of electrolyte solutions as well as pH on its particle size change was investigated. The average particle size and zeta potential of the nanoparticles in different electrolyte solutions were measured. The results show that addition of different concentrations of electrolytes changed the hydrodynamic diameter of nanoparticles in water. Increased concentration of tetramethyl ammonium hydroxide (TMAH) caused the zeta potential of nanoparticles to change from positive to negative and its hydrodynamic diameter to increase from 40 nm to 165 nm. In addition, increasing concentration of triflic acid led to the decrease of particle size and zeta potential. © (2015) COPYRIGHT Society of Photo-Optical Instrumentation Engineers (SPIE). Downloading of the abstract is permitted for personal use only.

  3. Metal hybrid nanoparticles for catalytic organic and photochemical transformations.

    Science.gov (United States)

    Song, Hyunjoon

    2015-03-17

    In order to understand heterogeneous catalytic reactions, model catalysts such as a single crystalline surface have been widely studied for many decades. However, catalytic systems that actually advance the reactions are three-dimensional and commonly have multiple components including active metal nanoparticles and metal oxide supports. On the other hand, as nanochemistry has rapidly been developed and been applied to various fields, many researchers have begun to discuss the impact of nanochemistry on heterogeneous catalysis. Metal hybrid nanoparticles bearing multiple components are structurally very close to the actual catalysts, and their uniform and controllable morphology is suitable for investigating the relationship between the structure and the catalytic properties in detail. In this Account, we introduce four typical structures of metal hybrid nanoparticles that can be used to conduct catalytic organic and photochemical reactions. Metal@silica (or metal oxide) yolk-shell nanoparticles, in which metal cores exist in internal voids surrounded by thin silica (or metal oxide) shells, exhibited extremely high thermal and chemical stability due to the geometrical protection of the silica layers against the metal cores. The morphology of the metal cores and the pore density of the hollow shells were precisely adjusted to optimize the reaction activity and diffusion rates of the reactants. Metal@metal oxide core-shell nanoparticles and inverted structures, where the cores supported the shells serving an active surface, exhibited high activity with no diffusion barriers for the reactants and products. These nanostructures were used as effective catalysts for various organic and gas-phase reactions, including hydrogen transfer, Suzuki coupling, and steam methane reforming. In contrast to the yolk- and core-shell structures, an asymmetric arrangement of distinct domains generated acentric dumbbells and tipped rods. A large domain of each component added multiple

  4. Biomolecule-nanoparticle hybrids as functional units for nanobiotechnology.

    Science.gov (United States)

    Baron, Ronan; Willner, Bilha; Willner, Itamar

    2007-01-28

    Biomolecule-metal or semiconductor nanoparticle (NP) hybrid systems combine the recognition and catalytic properties of biomolecules with the unique electronic and optical properties of NPs. This enables the application of the hybrid systems in developing new electronic and optical biosensors, to synthesize nanowires and nanocircuits, and to fabricate new devices. Metal NPs are employed as nano-connectors that activate redox enzymes, and they act as electrical or optical labels for biorecognition events. Similarly, semiconductor NPs act as optical probes for biorecognition processes. Double-stranded DNA or protein chains that are modified with metallic nanoclusters act as templates for the synthesis of metallic nanowires. The nanowires are used as building blocks to assemble nano-devices such as a transistor or a nanotransporter.

  5. Suspended hybrid films assembled from thiol-capped gold nanoparticles.

    Science.gov (United States)

    Zhang, Yu Xin; Huang, Ming; Hao, Xiao Dong; Dong, Meng; Li, Xin Lu; Huang, Jia Mu

    2012-01-01

    In this work, we explored the formation processes of suspended hybrid thin films of thiol-capped Au nanoparticles (AuNPs) inside metal oxide tubular structures. We found that a balance between in-film interactions of the AuNPs and boundary interactions with metal oxides is a key in making these special organic-inorganic thin films. The hybrid films process many processing advantages and flexibilities, such as controllable film thickness, interfacial shape and inter-AuNPs distance, tuning of particle sizes, thiol population, chain lengths, and other new properties by introducing functional groups to thiol chains. Among their many unique features, the assembly-disassembly property may be useful for future on-off or store-release applications.

  6. Novel hybrid coatings with controlled wettability by composite nanoparticle aggregation

    Science.gov (United States)

    Hritcu, Doina; Dodi, Gianina; Iordache, Mirabela L.; Draganescu, Dan; Sava, Elena; Popa, Marcel I.

    2016-11-01

    The aim of this study is to evaluate novel hybrid materials as potential candidates for producing coatings with hierarchical roughness and controlled wetting behaviour. Magnetite (Fe3O4) nanoparticles obtained by co-precipitation were embedded in matrices synthesized by radical graft co-polymerization of butyl acrylate (BA), butyl methacrylate (BMA), hexyl acrylate (HA) or styrene (ST) with ethylene glycol di-methacrylate (EGDMA) onto previously modified chitosan bearing surface vinyl groups. The resulting composite particles were characterized regarding their average size, composition and magnetic properties. Hybrid thin films containing suspension of composite particles in ethanol and pre-hydrolysed hexadecyltrimethoxysilane (HDTS) as a coupling/crosslinking agent were deposited by spin coating or spraying. The films were cured by heating and subsequently characterized regarding their morphology (scanning electron microscopy), contact angle with water and adhesion to substrate (scratch test). The structure-property relationship is discussed.

  7. Surface plasmon enhanced quantum transport in a hybrid metal nanoparticle array

    Energy Technology Data Exchange (ETDEWEB)

    Sun, Lin; Nan, Yali; Xu, Shang; Zhang, Sishi; Han, Min, E-mail: sjhanmin@nju.edu.cn

    2014-07-18

    Hybrid Pd–Ag nanoparticle arrays composed of randomly distributed Pd nanoparticles in dense packing and a small number of dispersed Ag nanoparticles were fabricated with controlled coverage. Photo-enhanced conductance was observed in the nanoparticle arrays. Largest enhancement, which can be higher than 20 folds, was obtained with 450 nm light illumination. This wavelength was found to correlate with the surface plasmon resonance of the Ag nanoparticles. Electron transport measurements showed there were significant Coulomb blockade in the nanoparticle arrays and the blockade could be overcome with the surface plasmon enhanced local field of Ag nanoparticles induced by light illumination. - Highlights: • We study photo-enhanced electron conductance of a hybrid Pd–Ag nanoparticle array. • The light-induced conductance enhancement is as high as 20 folds at 10 K. • The enhancement is correlate with the surface plasmon resonance of Ag nanoparticles. • Coulomb blockades is overcome with the surface plasmon enhanced local field.

  8. Surface plasmon enhanced quantum transport in a hybrid metal nanoparticle array

    Science.gov (United States)

    Sun, Lin; Nan, Yali; Xu, Shang; Zhang, Sishi; Han, Min

    2014-07-01

    Hybrid Pd-Ag nanoparticle arrays composed of randomly distributed Pd nanoparticles in dense packing and a small number of dispersed Ag nanoparticles were fabricated with controlled coverage. Photo-enhanced conductance was observed in the nanoparticle arrays. Largest enhancement, which can be higher than 20 folds, was obtained with 450 nm light illumination. This wavelength was found to correlate with the surface plasmon resonance of the Ag nanoparticles. Electron transport measurements showed there were significant Coulomb blockade in the nanoparticle arrays and the blockade could be overcome with the surface plasmon enhanced local field of Ag nanoparticles induced by light illumination.

  9. SYNTHESIS AND CHARACTERIZATION OF STRUCTURALLY WELL-DEFINED POLYMER-INORGANIC HYBRID NANOPARTICLES VIA ATRP

    Institute of Scientific and Technical Information of China (English)

    Jie Bai; Jie-bin Pang; Kun-yuan Qiu; Yen Wei

    2002-01-01

    Atom transfer radical polymerization (ATRP) using cuprous chloride/2,2'-bipyridine (bipy) was applied to graft polymerization of styrene on the surface of silica nanoparticles to synthesize polymer-inorganic hybrid nanoparticles. 2-(4-Chloromethylphenyl) ethyltriethoxysilane (CTES) was immobilized on the surface of silica nanoparticles through condensation reaction of the silanol groups on silica with triethoxysilane group of CTES. Then ATRP of St was initiated by this surface-modified silica nanoparticles bearing benzyl chloride groups, and formed PSt graft chains on the surface of silica nanoparticles. The thickness of the graft chains increased with reaction time. End group analysis confirmed the occurrence of ATRP. Thermal analysis indicated that thermal stabilization of these resulting hybrid nanoparticles also increases with polymerization conversion. The results above show that this "grafting from" reaction could be used for the preparation of polymer-inorganic hybrid nanoparticles with controlled structure of the polymer's end groups.

  10. Polymer and polymer-hybrid nanoparticles from synthesis to biomedical applications

    CERN Document Server

    Rangelov, Stanislav

    2013-01-01

    Polymeric and hybrid nanoparticles have received increased scientific interest in terms of basic research as well as commercial applications, promising a variety of uses for nanostructures in fields including bionanotechnology and medicine. Condensing the relevant research into a comprehensive reference, Polymer and Polymer-Hybrid Nanoparticles: From Synthesis to Biomedical Applications covers an array of topics from synthetic procedures and macromolecular design to possible biomedical applications of nanoparticles and materials based on original and unique polymers. The book presents a well-r

  11. Metallic nanoparticles in active layer for hybrid photovoltaic device applications

    Energy Technology Data Exchange (ETDEWEB)

    Yu, Yang-Yen, E-mail: yyyu@mail.mcut.edu.tw [Department of Materials Engineering, Ming Chi University of Technology, 84 Gunjuan Rd., Taishan Dist., New Taipei City, 24301, Taiwan (China); Center for Thin Film Technologies and Applications, Ming Chi University of Technology, 84 Gunjuan Rd., Taishan Dist., New Taipei City, 24301, Taiwan (China); Battery Research Center of Green Energy, Ming Chi University of Technology, 84 Gunjuan Rd., Taishan Dist., New Taipei City, 24301, Taiwan (China); Chan, Si-Han [Department of Materials Engineering, Ming Chi University of Technology, 84 Gunjuan Rd., Taishan Dist., New Taipei City, 24301, Taiwan (China)

    2013-10-01

    In this study, Poly (3-hexylthiophene) (P3HT): [6,6]-phenyl C61-butyric (PCBM): titania (TiO{sub 2}): platinum (Pt) nanoparticles (NPs) hybrid films were prepared and used as the active layer of solar cells. The use of nano-Pt in hybrid films may increase the efficiency of solar cells because of its high carrier mobility. The polyol reduction reaction was used to synthesize inorganic Pt NPs by dissolving H{sub 2}PtCl{sub 6}·6H{sub 2}O in ethylene glycol and refluxing the solvent for several hours. Then, the prepared Pt NPs were used to prepare the solar cells. The experimental results showed that the short-circuit current density and efficiency of solar cells increased from 7.31 mA/cm{sup 2} and 2.17% to 10.10 mA/cm{sup 2} and 3.26%, respectively. In addition, the value of incident photon-to-electron conversion efficiency reached 55% as 0.03 wt.% Pt NPs were added into the active layer P3HT:PCBM:TiO{sub 2}. - Highlights: • A P3HT:PCBM:TiO{sub 2} hybrid film was applied as an active layer. • Effect of Pt content on the efficiency of a solar cell was examined. • Solar cell with a 3.26% efficiency was fabricated.

  12. Hybrid nanoparticles improve targeting to inflammatory macrophages through phagocytic signals.

    Science.gov (United States)

    Bagalkot, Vaishali; Badgeley, Marcus A; Kampfrath, Thomas; Deiuliis, Jeffrey A; Rajagopalan, Sanjay; Maiseyeu, Andrei

    2015-11-10

    Macrophages are innate immune cells with great phenotypic plasticity, which allows them to regulate an array of physiological processes such as host defense, tissue repair, and lipid/lipoprotein metabolism. In this proof-of-principle study, we report that macrophages of the M1 inflammatory phenotype can be selectively targeted by model hybrid lipid-latex (LiLa) nanoparticles bearing phagocytic signals. We demonstrate a simple and robust route to fabricate nanoparticles and then show their efficacy through imaging and drug delivery in inflammatory disease models of atherosclerosis and obesity. Self-assembled LiLa nanoparticles can be modified with a variety of hydrophobic entities such as drug cargos, signaling lipids, and imaging reporters resulting in sub-100nm nanoparticles with low polydispersities. The optimized theranostic LiLa formulation with gadolinium, fluorescein and "eat-me" phagocytic signals (Gd-FITC-LiLa) a) demonstrates high relaxivity that improves magnetic resonance imaging (MRI) sensitivity, b) encapsulates hydrophobic drugs at up to 60% by weight, and c) selectively targets inflammatory M1 macrophages concomitant with controlled release of the payload of anti-inflammatory drug. The mechanism and kinetics of the payload discharge appeared to be phospholipase A2 activity-dependent, as determined by means of intracellular Förster resonance energy transfer (FRET). In vivo, LiLa targets M1 macrophages in a mouse model of atherosclerosis, allowing noninvasive imaging of atherosclerotic plaque by MRI. In the context of obesity, LiLa particles were selectively deposited to M1 macrophages within inflamed adipose tissue, as demonstrated by single-photon intravital imaging in mice. Collectively, our results suggest that phagocytic signals can preferentially target inflammatory macrophages in experimental models of atherosclerosis and obesity, thus opening the possibility of future clinical applications that diagnose/treat these conditions. Tunable Li

  13. Optoelectronic Properties of Hybrid Titania Nanotubes/Hematite Nanoparticles Structures

    Science.gov (United States)

    Wang, Lili; Panaitescu, Eugen; Menon, Latika

    2015-03-01

    TiO2/Fe2O3 nanostructures are becoming promising alternatives for improving cost effectiveness (in /W) of emerging photovoltaic devices such as dye sensitized or metal-insulator-semiconductor solar cells, combining the low cost, earth abundance and stability of the materials with the enhanced performance offered by the nanoscale architecture. We investigated novel, high quality titania/hematite composites, namely hematite nanoparticle decorated titania nanotube arrays, which were obtained by a simple, inexpensive and easily scalable two-step process, electrochemical anodization of titanium followed by forced hydrolysis. The titania nanotubular scaffold provides a large active surface area, while the iron oxide nanoparticles significantly broaden the light absorption range into the visible region. The morphological and structural characteristics of the samples were analyzed by scanning electron microscopy (SEM), X-ray diffraction (XRD) and transmission electron microscopy (TEM). The light absorption efficiency was measured by diffuse reflectance spectroscopy (DRS), and the optoelectronic behavior of the hybrid structures was analyzed by IV measurements under simulated solar illumination. The influence of the synthesis process and the structure design on the photovoltaic performance is currently investigated for optimal device prototyping.

  14. Hard and transparent films formed by nanocellulose-TiO2 nanoparticle hybrids.

    Directory of Open Access Journals (Sweden)

    Christina Schütz

    Full Text Available The formation of hybrids of nanofibrillated cellulose and titania nanoparticles in aqueous media has been studied. Their transparency and mechanical behavior have been assessed by spectrophotometry and nanoindentation. The results show that limiting the titania nanoparticle concentration below 16 vol% yields homogeneous hybrids with a very high Young's modulus and hardness, of up to 44 GPa and 3.4 GPa, respectively, and an optical transmittance above 80%. Electron microscopy shows that higher nanoparticle contents result in agglomeration and an inhomogeneous hybrid nanostructure with a concomitant reduction of hardness and optical transmittance. Infrared spectroscopy suggests that the nanostructure of the hybrids is controlled by electrostatic adsorption of the titania nanoparticles on the negatively charged nanocellulose surfaces.

  15. Novel hybrid nanostructured materials of magnetite nanoparticles and pectin

    Energy Technology Data Exchange (ETDEWEB)

    Sahu, Saurabh [Department of Chemistry, Indian Institute of Technology Roorkee, Roorkee 247 667 (India); Dutta, Raj Kumar, E-mail: duttafcy@iitr.ernet.i [Department of Chemistry, Indian Institute of Technology Roorkee, Roorkee 247 667 (India)

    2011-04-15

    A novel hybrid nanostructured material comprising superparamagnetic magnetite nanoparticles (MNPs) and pectin was synthesized by crosslinking with Ca{sup 2+} ions to form spherical calcium pectinate nanostructures, referred as MCPs, which were typically found to be 100-150 nm in size in dried condition, confirmed from transmission electron microscopy and scanning electron microscopy. The uniform size distribution was revealed from dynamic light scattering measurement. In aqueous medium the MCPs showed swelling behavior with an average size of 400 nm. A mechanism of formation of spherical MCPs is outlined constituting a MNP-pectin interface encapsulated by calcium pectinate at the periphery, by using an array of characterization techniques like zeta potential, thermogravimetry, Fourier transformed infrared and X-ray photoelectron spectroscopy. The MCPs were stable in simulated gastrointestinal fluid and ensured minimal loss of magnetic material. They exhibited superparamagnetic behavior, confirmed from zero field cooled and field cooled profiles and showed high saturation magnetization (M{sub s}) of 46.21 emu/g at 2.5 T and 300 K. M{sub s} decreased with increasing precursor pectin concentrations, attributed to quenching of magnetic moments by formation of a magnetic dead layer on the MNPs. - Research highlights: > In the present investigation we have developed a facile route to synthesize a novel, low cost calcium pectinate nanostructure functionalized with SPIONs (magnetite nanoparticles). > Though there are sufficient scientific illustrations on polymer as well as biopolymers coated on SPIONs for various biomedical applications, the one presented here, is novel of its kind as it is considered to offer a new dimension to the magnetic responsive properties of calcium pectinate nanomaterials towards biomedical applications, especially as a potential carrier for magnetically targeted drug delivery to colon specific sites. > The synthesis of these nanostructured

  16. Structure and Morphology of Organic Semiconductor–Nanoparticle Hybrids Prepared by Soft Deposition

    OpenAIRE

    Banerjee, R.; Novák, J.; Drnec, J.; Yu, S.; Schreiber, F.; C. Frank; Girleanu, M.; Ersen, O.; Brinkmann, M.; Anger, F.; Lorch, C.; Dieterle, J; Gerlach, A.

    2015-01-01

    We present an extensive structural analysis of hybrid architectures prepared by the “soft” incorporation of gold nanoparticles (AuNPs) within an organic semiconductor matrix of diindenoperylene (DIP). Such “soft” or noninvasive deposition of nanoparticles within organic semiconducting host matrices not only minimizes the influence of the deposition process on the order and properties of the organic host molecules, but also offers additional control in the process of incorporation. The hybrid ...

  17. Hard and Transparent Films Formed by Nanocellulose-TiO2 Nanoparticle Hybrids

    OpenAIRE

    Christina Schütz; Jordi Sort; Zoltán Bacsik; Vitaliy Oliynyk; Eva Pellicer; Andreas Fall; Lars Wågberg; Lars Berglund; Lennart Bergström; German Salazar-Alvarez

    2012-01-01

    The formation of hybrids of nanofibrillated cellulose and titania nanoparticles in aqueous media has been studied. Their transparency and mechanical behavior have been assessed by spectrophotometry and nanoindentation. The results show that limiting the titania nanoparticle concentration below 16 vol% yields homogeneous hybrids with a very high Young's modulus and hardness, of up to 44 GPa and 3.4 GPa, respectively, and an optical transmittance above 80%. Electron microscopy shows that higher...

  18. Morphology and Optical Properties of Bare and Silica Coated Hybrid Silver Nanoparticles.

    Science.gov (United States)

    Ghimire, Sushant; Lebek, Werner; Godehardt, Reinhold; Lee, Wan In; Adhikari, Rameshwar

    2016-05-01

    Owing to their wide applications in the field of optoelectronics, photonics, catalysis, and medicine; plasmonic metal nanoparticles are attaining considerable interest nowadays. The optical properties of these metal nanoparticles depend upon their size, shape, and surrounding medium. The present work studies the morphology and optical properties of bare silver nanoparticles and silica coated hybrid silver nanoparticles. Aqueous phase mediated synthesis and water-in-oil microemulsion mediated synthesis are two different wet chemical routes employed for nanosynthesis. Direct coating of silica is performed in water-in-oil microemulsion on pre-synthesized silver nanoparticles using tetraethyl orthosilicate as silica precursor. This study shows that using different wet chemical routes the size of the synthesized nanoparticles could be tuned. In addition, using reverse micelles as nanoreactors, the thickness of the silica shell around the core silver nanoparticles could be significantly controlled. Further, the optical properties of silver nanoparticles could be adjusted through the size and the surface coating. PMID:27483900

  19. A proposed mechanism of the influence of gold nanoparticles on DNA hybridization.

    Science.gov (United States)

    Sedighi, Abootaleb; Li, Paul C H; Pekcevik, Idah C; Gates, Byron D

    2014-07-22

    A combination of gold nanoparticles (AuNPs) and nucleic acids has been used in biosensing applications. However, there is a poor fundamental understanding of how gold nanoparticle surfaces influence the DNA hybridization process. Here, we measured the rate constants of the hybridization and dehybridization of DNA on gold nanoparticle surfaces to enable the determination of activation parameters using transition state theory. We show that the target bases need to be detached from the gold nanoparticle surfaces before zipping. This causes a shift of the rate-limiting step of hybridization to the mismatch-sensitive zipping step. Furthermore, our results propose that the binding of gold nanoparticles to the single-stranded DNA segments (commonly known as bubbles) in the duplex DNA stabilizes the bubbles and accelerates the dehybridization process. We employ the proposed mechanism of DNA hybridization/dehybridization to explain the ability of 5 nm diameter gold nanoparticles to help discriminate between single base-pair mismatched DNA molecules when performed in a NanoBioArray chip. The mechanistic insight into the DNA-gold nanoparticle hybridization/dehybridization process should lead to the development of new biosensors.

  20. Metal nanoparticle deposited inorganic nanostructure hybrids, uses thereof and processes for their preparation

    Energy Technology Data Exchange (ETDEWEB)

    Tenne, Reshef; Tsverin, Yulia; Burghaus, Uwe; Komarneni, Mallikharjuna Rao

    2016-01-26

    This invention relates to a hybrid component comprising at least one nanoparticle of inorganic layered compound (in the form of fullerene-like structure or nanotube), and at least one metal nanoparticle, uses thereof as a catalyst, (e.g. photocatalysis) and processes for its preparation.

  1. A transparent hybrid of nanocrystalline cellulose and amorphous calcium carbonate nanoparticles

    OpenAIRE

    Gebauer, Denis; Oliynyk, Vitaliy; Salajkova, Michaela; Sort, Jordi; Zhou, Qi; Bergström, Lennart; Salazar-Alvarez, German

    2011-01-01

    Nanocellulose hybrids are promising candidates for biodegradable multifunctional materials. Hybrids of nanocrystalline cellulose (NCC) and amorphous calcium carbonate (ACC) nanoparticles were obtained through a facile chemical approach over a wide range of compositions. Controlling the interactions between NCC and ACC results in hard, transparent structures with tunable composition, homogeneity and anisotropy.

  2. Lanthanide-Functionalized Hydrophilic Magnetic Hybrid Nanoparticles: Assembly, Magnetic Behaviour, and Photophysical Properties.

    Science.gov (United States)

    Han, Shuai; Tang, Yu; Guo, Haijun; Qin, Shenjun; Wu, Jiang

    2016-12-01

    The lanthanide-functionalized multifunctional hybrid nanoparticles combining the superparamagnetic core and the luminescent europium complex were successfully designed and assembled via layer-by-layer strategy in this work. It is noted that the hybrid nanoparticles were modified by a hydrophilic polymer polyethyleneimine (PEI) through hydrogen bonding which bestowed excellent hydrophilicity and biocompatibility on this material. A bright-red luminescence was observed by fluorescence microscopy, revealing that these magnetic-luminescent nanoparticles were both colloidally and chemically stable in PBS solution. Therefore, the nanocomposite with magnetic resonance response and fluorescence probe property is considered to be of great potential in multi-modal bioimaging and diagnostic applications. PMID:27245169

  3. Inorganic-Organic Hybrid 18-Molybdodiphosphate Nanoparticles Bulk-modified Carbon Paste Electrode and Its Electrocatalysis

    Institute of Scientific and Technical Information of China (English)

    WANG,Xiu-Li(王秀丽); KANG,Zhen-Hui(康振辉); WANG,En-Bo(王恩波); HU,Chang-Wen(胡长文)

    2002-01-01

    A kind of inorganic- organic hybrid 18-molybdodiphosphate nanoparticles ([(C4H9)4N]6P2Mo18O62 @4H2O) was firstly used as a bulk-modifier to fabricate a three-dimensional chemically modified carbon paste electrode (CPE) by direct mixing. The electrochemical behavior of the solid nanoparticles dispersed in the CPE in acidic aqueous solution was characterized by cyclic and square-wave voltammetry. The hybrid 18-molybdodiphosphate nanoparticles bulk-modified CPE (MNP-CPE) displayed a high electrocatalytic activity towards the reduction of nitrite,bromate and hydrogen peroxide. The remarkable advantages of the MNP-CPE over the traditional polyoxometalates-modified electrodes are their excellent reproducibility of surface-renewal and high stability owing to the insolubility of the hybrid 18-molybdodiphosphate nanoparticles.

  4. Novel hybrid nanostructured materials of magnetite nanoparticles and pectin

    Science.gov (United States)

    Sahu, Saurabh; Dutta, Raj Kumar

    2011-04-01

    A novel hybrid nanostructured material comprising superparamagnetic magnetite nanoparticles (MNPs) and pectin was synthesized by crosslinking with Ca2+ ions to form spherical calcium pectinate nanostructures, referred as MCPs, which were typically found to be 100-150 nm in size in dried condition, confirmed from transmission electron microscopy and scanning electron microscopy. The uniform size distribution was revealed from dynamic light scattering measurement. In aqueous medium the MCPs showed swelling behavior with an average size of 400 nm. A mechanism of formation of spherical MCPs is outlined constituting a MNP-pectin interface encapsulated by calcium pectinate at the periphery, by using an array of characterization techniques like zeta potential, thermogravimetry, Fourier transformed infrared and X-ray photoelectron spectroscopy. The MCPs were stable in simulated gastrointestinal fluid and ensured minimal loss of magnetic material. They exhibited superparamagnetic behavior, confirmed from zero field cooled and field cooled profiles and showed high saturation magnetization (Ms) of 46.21 emu/g at 2.5 T and 300 K. Ms decreased with increasing precursor pectin concentrations, attributed to quenching of magnetic moments by formation of a magnetic dead layer on the MNPs.

  5. Resonant photothermal laser processing of hybrid gold/titania nanoparticle films

    Energy Technology Data Exchange (ETDEWEB)

    Schade, Lina; Franzka, Steffen; Dzialkowski, Kevin [Fakultät für Chemie, Universität Duisburg-Essen, 45117 Essen (Germany); Center for Nanointegration Duisburg-Essen (CENIDE), University of Duisburg-Essen, Carl-Benz-Straße 199, 47057 Duisburg (Germany); Hardt, Sebastian; Wiggers, Hartmut [Center for Nanointegration Duisburg-Essen (CENIDE), University of Duisburg-Essen, Carl-Benz-Straße 199, 47057 Duisburg (Germany); Institut für Verbrennung und Gasdynamik, Universität Duisburg-Essen, 47048 Duisburg (Germany); Reichenberger, Sven [Fakultät für Chemie, Universität Duisburg-Essen, 45117 Essen (Germany); Center for Nanointegration Duisburg-Essen (CENIDE), University of Duisburg-Essen, Carl-Benz-Straße 199, 47057 Duisburg (Germany); Institut für Lacke und Oberflächenchemie, Hochschule Niederrhein, 47798 Krefeld (Germany); Wagener, Philipp [Fakultät für Chemie, Universität Duisburg-Essen, 45117 Essen (Germany); Center for Nanointegration Duisburg-Essen (CENIDE), University of Duisburg-Essen, Carl-Benz-Straße 199, 47057 Duisburg (Germany); Hartmann, Nils, E-mail: nils.hartmann@uni-due.de [Fakultät für Chemie, Universität Duisburg-Essen, 45117 Essen (Germany); Center for Nanointegration Duisburg-Essen (CENIDE), University of Duisburg-Essen, Carl-Benz-Straße 199, 47057 Duisburg (Germany)

    2015-05-01

    Graphical abstract: - Highlights: • Photothermal processing of TiO{sub 2} and hybrid Au/TiO{sub 2} nanoparticles using continuous-wave lasers is demonstrated. • Processing of TiO{sub 2} nanoparticles at 355 nm results in a transition from anatase to rutile. • Decoration of TiO{sub 2} nanoparticles with Au nanoparticles results in an increased absorbance in the visible range. • Hybrid Au/TiO{sub 2} nanoparticles can be processed at 355 nm and 532 nm in a large laser parameter window. • Processing of hybrid Au/TiO{sub 2} nanoparticles at 532 nm can be carried out at low laser powers and short laser pulse lengths. - Abstract: Photothermal processing of thin anatase TiO{sub 2} and hybrid Au/anatase TiO{sub 2} nanoparticle films on glass supports is investigated using continuous-wave microfocused lasers at λ = 355 nm and λ = 532 nm. UV/Vis spectroscopy, Raman spectroscopy, optical microscopy, atomic force microscopy and scanning electron microscopy are used for characterization. Processing of TiO{sub 2} nanoparticle films is feasible at λ = 355 nm only. In contrast, the addition of Au nanoparticles enhances the overall absorbance of the material in the visible range and enables processing at both wavelengths, i.e. at λ = 355 nm and λ = 532 nm. Generally, laser heating induces a transition from anatase to rutile. The modification degree increases with increasing laser power and laser irradiation time. Resonant laser processing of hybrid Au/TiO{sub 2}-mesoporous films provide promising perspectives in various applications, e.g. in photovoltaics, where embedded nanoparticulate Au could be exploited to enhance light trapping.

  6. Air stable organic-inorganic nanoparticles hybrid solar cells

    Science.gov (United States)

    Qian, Lei; Yang, Jihua; Xue, Jiangeng; Holloway, Paul H.

    2015-09-29

    A solar cell includes a low work function cathode, an active layer of an organic-inorganic nanoparticle composite, a ZnO nanoparticle layer situated between and physically contacting the cathode and active layers; and a transparent high work function anode that is a bilayer electrode. The inclusion of the ZnO nanoparticle layer results in a solar cell displaying a conversion efficiency increase and reduces the device degradation rate. Embodiments of the invention are directed to novel ZnO nanoparticles that are advantageous for use as the ZnO nanoparticle layers of the novel solar cells and a method to prepare the ZnO nanoparticles.

  7. Localized surface plasmon resonance-based hybrid Au-Ag nanoparticles for detection of Staphylococcus aureus enterotoxin B

    Science.gov (United States)

    Zhu, Shaoli; Du, ChunLei; Fu, Yongqi

    2009-09-01

    A triangular hybrid Au-Ag nanoparticles array was proposed for the purpose of biosensing in this paper. Constructing the hybrid nanoparticles, an Au thin film is capped on the Ag nanoparticles which are attached on glass substrate. The hybrid nanoparticles array was designed by means of finite-difference and time-domain (FDTD) algorithm-based computational numerical calculation and optimization. Sensitivity of refractive index of the hybrid nanoparticles array was obtained by the computational calculation and experimental detection. Moreover, the hybrid nanoparticles array can prevent oxidation of the pure Ag nanoparticles from atmosphere environment because the Au protective layer was deposited on top of the Ag nanoparticles so as to isolate the Ag particles from the atmosphere. We presented a novel surface covalent link method between the localized surface plasmon resonance (LSPR) effect-based biosensors with hybrid nanoparticles array and the detected target molecules. The generated surface plasmon wave from the array carries the biological interaction message into the corresponding spectra. Staphylococcus aureus enterotoxin B (SEB), a small protein toxin was directly detected at nanogramme per milliliter level using the triangular hybrid Au-Ag nanoparticles. Hence one more option for the SEB detection is provided by this way.

  8. Synthesis and Microstructural Investigations of Organometallic Pd(II Thiol-Gold Nanoparticles Hybrids

    Directory of Open Access Journals (Sweden)

    Cervellino Antonio

    2008-01-01

    Full Text Available Abstract In this work the synthesis and characterization of gold nanoparticles functionalized by a novel thiol-organometallic complex containing Pd(II centers is presented. Pd(II thiol,trans, trans-[dithiolate-dibis(tributylphosphinedipalladium(II-4,4′-diethynylbiphenyl] was synthesized and linked to Au nanoparticles by the chemical reduction of a metal salt precursor. The new hybrid made of organometallic Pd(II thiol-gold nanoparticles, shows through a single S bridge a direct link between Pd(II and Au nanoparticles. The size-control of the Au nanoparticles (diameter range 2–10 nm was achieved by choosing the suitable AuCl4 −/thiol molar ratio. The size, strain, shape, and crystalline structure of these functionalized nanoparticles were determined by a full-pattern X-ray powder diffraction analysis, high-resolution TEM, and X-ray photoelectron spectroscopy. Photoluminescence spectroscopy measurements of the hybrid system show emission peaks at 418 and 440 nm. The hybrid was exposed to gaseous NO x with the aim to evaluate the suitability for applications in sensor devices; XPS measurements permitted to ascertain and investigate the hybrid –gas interaction.

  9. Ultra-small lipid-polymer hybrid nanoparticles for tumor-penetrating drug delivery

    Science.gov (United States)

    Dehaini, Diana; Fang, Ronnie H.; Luk, Brian T.; Pang, Zhiqing; Hu, Che-Ming J.; Kroll, Ashley V.; Yu, Chun Lai; Gao, Weiwei; Zhang, Liangfang

    2016-07-01

    Lipid-polymer hybrid nanoparticles, consisting of a polymeric core coated by a layer of lipids, are a class of highly scalable, biodegradable nanocarriers that have shown great promise in drug delivery applications. Here, we demonstrate the facile synthesis of ultra-small, sub-25 nm lipid-polymer hybrid nanoparticles using an adapted nanoprecipitation approach and explore their utility for targeted delivery of a model chemotherapeutic. The fabrication process is first optimized to produce a monodisperse population of particles that are stable under physiological conditions. It is shown that these ultra-small hybrid nanoparticles can be functionalized with a targeting ligand on the surface and loaded with drug inside the polymeric matrix. Further, the in vivo fate of the nanoparticles after intravenous injection is characterized by examining the blood circulation and biodistribution. In a final proof-of-concept study, targeted ultra-small hybrid nanoparticles loaded with the cancer drug docetaxel are used to treat a mouse tumor model and demonstrate improved efficacy compared to a clinically available formulation of the drug. The ability to synthesize a significantly smaller version of the established lipid-polymer hybrid platform can ultimately enhance its applicability across a wider range of applications.

  10. Preparation of porous chitosan-poly(acrylic acid)-calcium phosphate hybrid nanoparticles via mineralization

    Institute of Scientific and Technical Information of China (English)

    CHEN ChangJing; DENG Yu; YAN ErYun; HU Yong; JIANG XiQun

    2009-01-01

    In this work,the preparation of chitosan-poly(acrylic acid)-calcium phosphate hybrid nanoparticles (CS-PAA-CaP NP) based on the mineralization of calcium phosphate (CAP) on the surface of chitosan-poly (acrylic acid) nanoparticles (CS-PAA NPs) was reported. CS-PAA-CaP NPs were achieved by directly adding ammonia to the aqueous solution of CS-PAA nanoparticles or by thermal decomposition of urea in the aqueous solution of CS-PAA nanoparticles,resulting in the mineralization of CaP on the surface of CS-PAA NPs. Through these two routes,especially using urea as a pH-regulator,the precipitation of CS-PAA NPs,a common occurrence in basic environment,was avoided. The size,morphology and ingredient of CS-PAA-CaP hybrid nanoparticles were characterized by dynamic light scattering (DLS),transmission electron microscope (TEM),scanning electron microscope (SEM),thermogravimetry analysis (TGA) and X-ray diffractometer (XRD). When urea was used as the pH regulator to facilitate the mineralization during the thermal urea decomposition procedure,regular CS-PAA-CaP hybrid nanoparticles with a porosity-structural CaP shells and 400-600 nm size were obtained. TGA result revealed that the hybrid NPs contained approximately 23% inorganic component,which was consistent with the ratio of starting materials. The XRD spectra of hybrid nanoparticles indicated that dicalcium phosphate (DCP:CaHPO4) crystal was a dominant component of mineralization.The porous structure of the CS-PAA-CaP hybrid NPs might be greatly useful in pharmaceutical and other medical applications.

  11. Synthesis and characterization of hybrid silica/PMMA nanoparticles and their use as filler in dental composites

    Energy Technology Data Exchange (ETDEWEB)

    Canché-Escamilla, G., E-mail: gcanche@cicy.mx [Unidad de Materiales, Centro de Investigación Científica de Yucatán A.C. Calle 43 No. 130 Col. Chuburná de Hidalgo, Mérida, Yucatán 97200 (Mexico); Duarte-Aranda, S. [Unidad de Materiales, Centro de Investigación Científica de Yucatán A.C. Calle 43 No. 130 Col. Chuburná de Hidalgo, Mérida, Yucatán 97200 (Mexico); Toledano, M. [Facultad de Odontología, Universidad de Granada, Campus Universitario de Cartuja s/n, Granada 18071 (Spain)

    2014-09-01

    The effect of hybrid silica/poly(methylmethacrylate) (PMMA) nanoparticles on the properties of composites for dental restoration was evaluated. Hybrid nanoparticles with silica as core and PMMA as shell were obtained by a seeded emulsion polymerization process. Fourier transform infrared spectrum of the hybrid nanoparticles shows an intense peak at 1730 cm{sup −1}, corresponding to carbonyl groups (C=O) of the ester. The thermal stability of the hybrid particles decreases with increasing amounts of PMMA and the residual mass at 700 °C corresponds to the silica content in the hybrid particles. Composites were obtained by dispersing nanoparticles (silica or hybrid), as fillers, in a resin—bis glycidyl dimethacrylate (Bis-GMA)/triethylene glycol dimethacrylate (TEGDMA) (40%/60% (w/w)). The paste was then placed in a mold and polymerized under light irradiation. During the preparation of the composites, with the hybrid nanoparticles, the monomers swell the PMMA shell and after photo-curing, a semi-interpenetrating network (semi-IPN) is obtained around the silica core. The properties of the composites, obtained using the hybrid nanoparticles, depend on the filler content and the amount of PMMA in the semi-IPN matrix. For composites with similar inorganic filler contents, the composites with low amounts of PMMA shell had higher modulus than those in which silica was used as the filler. - Highlights: • Hybrid nanoparticles silica/PMMA were used as fillers in dental composites. • The properties of the hybrid nanoparticle depend on the silica/PMMA content ratio. • A higher content of inorganic filler was obtained using hybrid nanoparticle. • Composites with higher modulus were obtained using hybrid nanoparticles. • A semi-IPN matrix between the PMMA shell and the resin is obtained.

  12. Polystyrene-Core-Silica-Shell Hybrid Particles Containing Gold and Magnetic Nanoparticles.

    Science.gov (United States)

    Tian, Jia; Vana, Philipp

    2016-02-18

    Polystyrene-core-silica-shell hybrid particles were synthesized by combining the self-assembly of nanoparticles and the polymer with a silica coating strategy. The core-shell hybrid particles are composed of gold-nanoparticle-decorated polystyrene (PS-AuNP) colloids as the core and silica particles as the shell. PS-AuNP colloids were generated by the self-assembly of the PS-grafted AuNPs. The silica coating improved the thermal stability and dispersibility of the AuNPs. By removing the "free" PS of the core, hollow particles with a hydrophobic cage having a AuNP corona and an inert silica shell were obtained. Also, Fe3O4 nanoparticles were encapsulated in the core, which resulted in magnetic core-shell hybrid particles by the same strategy. These particles have potential applications in biomolecular separation and high-temperature catalysis and as nanoreactors.

  13. Highly sensitive and rapid bacteria detection using molecular beacon-Au nanoparticles hybrid nanoprobes.

    Science.gov (United States)

    Cao, Jing; Feng, Chao; Liu, Yan; Wang, Shouyu; Liu, Fei

    2014-07-15

    Since many diseases are caused by pathogenic bacterial infections, accurate and rapid detection of pathogenic bacteria is in urgent need to timely apply appropriate treatments and to reduce economic costs. To end this, we designed molecular beacon-Au nanoparticle hybrid nanoprobes to improve the bacterial detection efficiency and sensitivity. Here, we show that the designed molecular beacon modified Au nanoparticles could specifically recognize synthetic DNAs targets and can readily detect targets in clinical samples. Moreover, the hybrid nanoprobes can recognize Escherichia coli within an hour at a concentration of 10(2) cfu/ml, which is 1000-folds sensitive than using molecular beacon directly. Our results show that the molecular beacon-Au nanoparticle hybrid nanoprobes have great potential in medical and biological applications.

  14. Studying the Mechanism of Hybrid Nanoparticle Photoresists: Effect of Particle Size on Photopatterning

    KAUST Repository

    Li, Li

    2015-07-28

    © 2015 American Chemical Society. Hf-based hybrid photoresist materials with three different organic ligands were prepared by a sol-gel-based method, and their patterning mechanism was investigated in detail. All hybrid nanoparticle resists are patternable using UV exposure. Their particle sizes show a dramatic increase from the initial 3-4 nm to submicron size after exposure, with no apparent inorganic content or thermal property change detected. XPS results showed that the mass percentage of the carboxylic group in the structure of nanoparticles decreased with increasing exposure duration. The particle coarsening sensitivities of those hybrid nanoparticles are consistent with their EUV performance. The current work provides an understanding for the development mechanism and future guidance for the design and processing of high performance resist materials for large-scale microelectronics device fabrication.

  15. Laser-ablated titania nanoparticles for aqueous processed hybrid solar cells

    Science.gov (United States)

    Körstgens, V.; Pröller, S.; Buchmann, T.; Moseguí González, D.; Song, L.; Yao, Y.; Wang, W.; Werhahn, J.; Santoro, G.; Roth, S. V.; Iglev, H.; Kienberger, R.; Müller-Buschbaum, P.

    2015-02-01

    Titania nanoparticles are produced by laser ablation in liquid in order to initiate functionalization of titania with the polymer for the active layer. By combining these titania nanoparticles and water-soluble poly[3-(potassium-6-hexanoate)thiophene-2,5-diyl] (P3P6T) hybrid solar cells are realized.Titania nanoparticles are produced by laser ablation in liquid in order to initiate functionalization of titania with the polymer for the active layer. By combining these titania nanoparticles and water-soluble poly[3-(potassium-6-hexanoate)thiophene-2,5-diyl] (P3P6T) hybrid solar cells are realized. Electronic supplementary information (ESI) available: Full scheme of the production of solar cells, additional spectra and details of the measurement techniques. See DOI: 10.1039/c4nr06782g

  16. Core shell hybrids based on noble metal nanoparticles and conjugated polymers: synthesis and characterization

    OpenAIRE

    Battocchio Chiara; Polzonetti Giovanni; Cametti Cesare; Fratoddi Ilaria; Venditti Iole; Russo Maria

    2011-01-01

    Abstract Noble metal nanoparticles of different sizes and shapes combined with conjugated functional polymers give rise to advanced core shell hybrids with interesting physical characteristics and potential applications in sensors or cancer therapy. In this paper, a versatile and facile synthesis of core shell systems based on noble metal nanoparticles (AuNPs, AgNPs, PtNPs), coated by copolymers belonging to the class of substituted polyacetylenes has been developed. The polymeric shells cont...

  17. Ionic Liquid-Nanoparticle Hybrid Electrolytes and their Application in Secondary Lithium-Metal Batteries

    KAUST Repository

    Lu, Yingying

    2012-07-12

    Ionic liquid-tethered nanoparticle hybrid electrolytes comprised of silica nanoparticles densely grafted with imidazolium-based ionic liquid chains are shown to retard lithium dendrite growth in rechargeable batteries with metallic lithium anodes. The electrolytes are demonstrated in full cell studies using both high-energy Li/MoS2 and high-power Li/TiO2 secondary batteries. Copyright © 2012 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  18. Symmetry breaking polymerization: one-pot synthesis of plasmonic hybrid Janus nanoparticles.

    Science.gov (United States)

    Wang, Yanming; Ding, Tao; Baumberg, Jeremy J; Smoukov, Stoyan K

    2015-06-21

    Asymmetric hybrid nanoparticles have many important applications in catalysis, nanomotion, sensing, and diagnosis, however ways to generate the asymmetric hybrid nanoparticles are quite limited and inefficient. Most current methods rely on interfacial adhesion and modification of already formed particles. In this article we report a one-pot, facile and scalable synthesis of anisotropic Au-polymer hybrid nanoparticles via interfacial oxidative dispersion polymerization. The interfacial nucleation and polymerization lead to spontaneous symmetry breaking and formation of the Janus particles. The reaction is initiated by monomer radicals generated by the strong oxidant HAuCl4, which is itself later reduced by the electron-rich monomers to self-nucleate and form Au nanoparticles (NPs). The competition between divinylbenzene adsorption and the PVP capping agent results in effective partial surface wetting, forming asymmetric Au-PDVB hybrid nanoparticles, by confining growth of each material to its own phase. Such spontaneous symmetry breaking, important in morphogenesis, with control over the subsequent growth processes should lead to significant advances in the synthesis of asymmetric nanostructures.

  19. Hybridizing Poly(ε-caprolactone) and Plasmonic Titanium Nitride Nanoparticles for Broadband Photoresponsive Shape Memory Films.

    Science.gov (United States)

    Ishii, Satoshi; Uto, Koichiro; Niiyama, Eri; Ebara, Mitsuhiro; Nagao, Tadaaki

    2016-03-01

    Plasmonic nanoparticles can confine light in nanoscale and locally heat the surrounding. Here we use titanium nitride (TiN) nanoparticles as broadband plasmonic light absorbers and synthesized a highly photoresponsive hybrid cross-linked polymer from shape memory polymer poly(ε-caprolactone) (PCL). The TiN-PCL hybrid is responsive to sunlight and the threshold irradiance was among the lowest when compared with other photoresponsive shape memory polymers studied previously. Sunlight heating with TiN NPs can be applied to other heat responsive smart polymers, thereby contributing to energy-saving smart polymers research for a sustainable society.

  20. Magnetic field activated lipid-polymer hybrid nanoparticles for stimuli-responsive drug release.

    Science.gov (United States)

    Kong, Seong Deok; Sartor, Marta; Hu, Che-Ming Jack; Zhang, Weizhou; Zhang, Liangfang; Jin, Sungho

    2013-03-01

    Stimuli-responsive nanoparticles (SRNPs) offer the potential of enhancing the therapeutic efficacy and minimizing the side-effects of chemotherapeutics by controllably releasing the encapsulated drug at the target site. Currently controlled drug release through external activation remains a major challenge during the delivery of therapeutic agents. Here we report a lipid-polymer hybrid nanoparticle system containing magnetic beads for stimuli-responsive drug release using a remote radio frequency (RF) magnetic field. These hybrid nanoparticles show long-term stability in terms of particle size and polydispersity index in phosphate-buffered saline (PBS). Controllable loading of camptothecin (CPT) and Fe(3)O(4) in the hybrid nanoparticles was demonstrated. RF-controlled drug release from these nanoparticles was observed. In addition, cellular uptake of the SRNPs into MT2 mouse breast cancer cells was examined. Using CPT as a model anticancer drug the nanoparticles showed a significant reduction in MT2 mouse breast cancer cell growth in vitro in the presence of a remote RF field. The ease of preparation, stability, and controllable drug release are the strengths of the platform and provide the opportunity to improve cancer chemotherapy.

  1. Direct laser planting of hybrid Au-Ag/C nanostructures - nanoparticles, flakes and flowers

    CERN Document Server

    Manshina, Alina; Bashouti, Muhammad; Povolotskiy, Alexey; Petrov, Yuriy; Koshevoy, Igor; Christiansen, Silke; Tunik, Sergey; Leuchs, Gerd

    2015-01-01

    We demonstrate a new approach for forming hybrid metal/carbonaceous nanostructures in a controlled direct laser planting process. Au-Ag nanoclusters in amorphous or crystalline carbonaceous matrices are formed with different morphology: nanoparticles, nanoflakes, and nanoflowers. In contrast to other generation techniques our approach is simple, involving only a single laser-induced process transforming supramolecular complexes dissolved in solvent such as acetone, acetophenone, or dichloroethane into hybrid nanostructures in the laser-affected area of the substrate. The morphology of the hybrid nanostructures can be steered by controlling the deposition parameters, the composition of the liquid phase and the type of substrate, amorphous or crystalline. The carbonaceous phase of the hybrid nanostructures consists of hydrogenated amorphous carbon in the case of nanoparticles and of crystalline orthorhombic graphite of nanoscale thickness in the case of flakes and flowers. To the best of our knowledge this is t...

  2. A transparent hybrid of nanocrystalline cellulose and amorphous calcium carbonate nanoparticles

    Science.gov (United States)

    Gebauer, Denis; Oliynyk, Vitaliy; Salajkova, Michaela; Sort, Jordi; Zhou, Qi; Bergström, Lennart; Salazar-Alvarez, German

    2011-09-01

    Nanocellulose hybrids are promising candidates for biodegradable multifunctional materials. Hybrids of nanocrystalline cellulose (NCC) and amorphous calcium carbonate (ACC) nanoparticles were obtained through a facile chemical approach over a wide range of compositions. Controlling the interactions between NCC and ACC results in hard, transparent structures with tunable composition, homogeneity and anisotropy.Nanocellulose hybrids are promising candidates for biodegradable multifunctional materials. Hybrids of nanocrystalline cellulose (NCC) and amorphous calcium carbonate (ACC) nanoparticles were obtained through a facile chemical approach over a wide range of compositions. Controlling the interactions between NCC and ACC results in hard, transparent structures with tunable composition, homogeneity and anisotropy. Electronic supplementary information (ESI) available: Additional experimental procedures and results. See DOI: 10.1039/c1nr10681c

  3. Refractive indices and birefringence of hybrid liquid crystal - nanoparticles composite materials in the terahertz region

    Directory of Open Access Journals (Sweden)

    E. Mavrona

    2015-07-01

    Full Text Available We show that a hybrid LC-ferroelectric nanoparticle suspension of liquid crystal E7 doped with BaTiO3 nanoparticles leads to 10% increase in birefringence in the THz region of spectrum as compared to pure E7. Doped liquid crystals can be used to increase performance of THz modulators and waveplates. BaTiO3 nanoparticles used in the mixture were synthesised with the sol gel technique, and their refractive index has been measured in THz in powder form and in solution.

  4. Construction and characterization of hybrid nanoparticles via block copolymer blends and kinetic control of solution assembly

    Science.gov (United States)

    Chen, Yingchao

    Amphiphilic block copolymers are able to self-assemble into well-defined nanostructures in aqueous solutions or aqueous/miscible organic solutions. These structures include traditional spheres, cylinders and vesicles, which mimic nanostructures formed by small molecule analogs like lipids and surfactants. The large molecular weight and complex macromolecular architectures provide several advantages over small molecule amphiphiles, including the large chemical versatility, control over the size and shape of the solution assemblies, unique slow chain exchange and exceptional increased versatility in possible nanostructures. These advantages have motivated the noteworthy study of constructing well-defined, controlled and, especially, multicompartment and multigeometry polymeric nanoobjects for potential multiple nanotechnology applications. To reach complexity and well-controlled nanostructures, the facile utility and fundamental understanding of the parameters that influence the effective construction of solution assemblies needs to be continued. Given these motivations, this dissertation demonstrated the design of block copolymers, manipulation of kinetic control parameters of solution assembly, and characterization of hybrid nanostructures with the aim of creating new, well-defined nanostructures. The first objective of this dissertation was to explore the effects of solvent processing rates in influencing multicompartment and multigeometry nanoparticle construction, structure evolution over long-time aging and nanoparticle formation mechanisms. The noticeable effects of water addition rates on the formation of various nanostructures were studied by cryogenic transmission electron microscopy, selective staining and small angle scattering. It was revealed that the water addition rate have significant influence over the final assemblies in block copolymer blends. New shapes of multicompartment and multigeometry nanoparticles have been constructed including hybrid

  5. Synthesis, characterization and functionalization of silicon nanoparticle based hybrid nanomaterials for photovoltaic and biological applications

    Science.gov (United States)

    Xu, Zejing

    Silicon nanoparticles are attractive candidates for biological, photovoltaic and energy storage applications due to their size dependent optoelectronic properties. These include tunable light emission, high brightness, and stability against photo-bleaching relative to organic dyes (see Chapter 1). The preparation and characterization of silicon nanoparticle based hybrid nanomaterials and their relevance to photovoltaic and biological applications are described. The surface-passivated silicon nanoparticles were produced in one step from the reactive high-energy ball milling (RHEBM) of silicon wafers with various organic ligands. The surface structure and optical properties of the passivated silicon nanoparticles were systematically characterized. Fast approaches for purifying and at the same time size separating the silicon nanoparticles using a gravity GPC column were developed. The hydrodynamic diameter and size distribution of these size-separated silicon nanoparticles were determined using GPC and Diffusion Ordered NMR Spectroscopy (DOSY) as fast, reliable alternative approaches to TEM. Water soluble silicon nanoparticles were synthesized by grafting PEG polymers onto functionalized silicon nanoparticles with distal alkyne or azide moieties. The surface-functionalized silicon nanoparticles were produced from the reactive high-energy ball milling (RHEBM) of silicon wafers with a mixture of either 5-chloro-1-pentyne in 1-pentyne or 1,7 octadiyne in 1-hexyne to afford air and water stable chloroalkyl or alkynyl terminated nanoparticles, respectively. Nanoparticles with the ω-chloroalkyl substituents were easily converted to ω-azidoalkyl groups through the reaction of the silicon nanoparticles with sodium azide in DMF. The azido terminated nanoparticles were then grafted with monoalkynyl-PEG polymers using a copper catalyzed alkyne-azide cycloaddition (CuAAC) reaction to afford core-shell silicon nanoparticles with a covalently attached PEG shell. Covalently

  6. Preparation and antibacterial properties of hybrid-zirconia films with silver nanoparticles

    Energy Technology Data Exchange (ETDEWEB)

    Azocar, Ignacio, E-mail: manuel.azocar@usach.cl [Departamento de Quimica de los Materiales, Facultad de Quimica y Biologia, Universidad de Santiago de Chile, USACH, Avenida Bernardo O' Higgins 3363, Casilla 40, Correo 33, Santiago (Chile); Vargas, Esteban [Facultad de Ingenieria, Departamento de Metalurgia, Universidad de Santiago de Chile, USACH (Chile); Duran, Nicole [Departamento de Quimica de los Materiales, Facultad de Quimica y Biologia, Universidad de Santiago de Chile, USACH, Avenida Bernardo O' Higgins 3363, Casilla 40, Correo 33, Santiago (Chile); Arrieta, Abel [Departamento de Biologia, Facultad de Quimica y Biologia, Universidad de Santiago de Chile, USACH (Chile); Gonzalez, Evelyn [Departamento de Quimica de los Materiales, Facultad de Quimica y Biologia, Universidad de Santiago de Chile, USACH, Avenida Bernardo O' Higgins 3363, Casilla 40, Correo 33, Santiago (Chile); Facultad de Ingenieria, Departamento de Metalurgia, Universidad de Santiago de Chile, USACH (Chile); Departamento de Biologia, Facultad de Quimica y Biologia, Universidad de Santiago de Chile, USACH (Chile); Departamento de Quimica Farmacologica y Toxicologica, Facultad de Ciencias Quimicas, Universidad de Chile, Sergio Livingstone Polhammer 1007, Santiago (Chile); and others

    2012-11-15

    The antimicrobial effect of incorporating silver nanoparticles (AgNps) into zirconia matrix-polyether glycol was studied. AgNps of 4-6 nm in size were synthesized using the inverse micelles method, and different doses of metallic nanoparticles were incorporated into zirconia-polyether glycol mixtures during the ageing procedure. Atomic force microscopy (AFM) of the modified hybrid film showed a homogenous distribution of 20-80 nm diameter AgNps, indicating agglomeration of these structures during film modification; such agglomerations were greater when increasing the dosage of the colloidal system. The AgNps-hybrid films showed higher antimicrobial activity against Gram-positive bacteria than for Gram-negative bacteria. Hybrid films prepared with dioctyl sodium sulfosuccinate (AOT) stabilized AgNps presented enhanced antibacterial activity compared to that obtained through the addition of a high AgNO{sub 3} concentration (0.3 wt%). -- Graphical abstract: Atomic Force Micrographs, top and cross section view, showing silver nanoparticles embedded in a zirconia-polyether glycol hybrid film. Highlights: Black-Right-Pointing-Pointer Antibacterial activity of films (zirconia-polyether glycol) modified with silver nanoparticles. Black-Right-Pointing-Pointer Biofilm formation is prevented. Black-Right-Pointing-Pointer High sensibility against gram positive bacteria.

  7. Facile Synthesis of Yolk-Shell-Structured Triple-Hybridized Periodic Mesoporous Organosilica Nanoparticles for Biomedicine.

    Science.gov (United States)

    Teng, Zhaogang; Zhang, Junjie; Li, Wei; Zheng, Yuanyi; Su, Xiaodan; Tang, Yuxia; Dang, Meng; Tian, Ying; Yuwen, Lihui; Weng, Lixing; Lu, Guangming; Wang, Lianhui

    2016-07-01

    The synthesis of mesoporous nanoparticles with controllable structure and organic groups is important for their applications. In this work, yolk-shell-structured periodic mesoporous organosilica (PMO) nanoparticles simultaneously incorporated with ethane-, thioether-, and benzene-bridged moieties are successfully synthesized. The preparation of the triple-hybridized PMOs is via a cetyltrimethylammonium bromide-directed sol-gel process using mixed bridged silsesquioxanes as precursors and a following hydrothermal treatment. The yolk-shell-structured triple-hybridized PMO nanoparticles have large surface area (320 m(2) g(-1) ), ordered mesochannels (2.5 nm), large pore volume (0.59 cm(3) g(-1) ), uniform and controllable diameter (88-380 nm), core size (22-110 nm), and shell thickness (13-45 nm). In vitro cytotoxicity, hemolysis assay, and histological studies demonstrate that the yolk-shell-structured triple-hybridized PMO nanoparticles have excellent biocompatibility. Moreover, the organic groups in the triple-hybridized PMOs endow them with an ability for covalent connection of near-infrared fluorescence dyes, a high hydrophobic drug loading capacity, and a glutathione-responsive drug release property, which make them promising candidates for applications in bioimaging and drug delivery. PMID:27183872

  8. Mechanistic profiling of the siRNA delivery dynamics of lipid-polymer hybrid nanoparticles

    DEFF Research Database (Denmark)

    Colombo, Stefano; Cun, Dongmei; Remaut, Katrien;

    2015-01-01

    Understanding the delivery dynamics of nucleic acid nanocarriers is fundamental to improve their design for therapeutic applications. We investigated the carrier structure-function relationship of lipid-polymer hybrid nanoparticles (LPNs) consisting of poly(dl-lactic-co-glycolic acid) (PLGA...

  9. Preparation and characterization of TiO 2-cationic hybrid nanoparticles as electrophoretic particles

    Science.gov (United States)

    Li, Jingjing; Deng, Liandong; Xing, Jinfeng; Dong, Anjie; Li, Xianggao

    2012-01-01

    The hybrid nanoparticles (TiO2-HNPs) with TiO2 nanoparticles as core and with poly(N,N-dimethylaminoethyl methacrylate-co-methyl methacrylate) by using triallylamine as cross-linking agent as shell were firstly prepared via atom transfer radical polymerization (ATRP) in methanol. Then the hybrid nanoparticles with positive charge were produced by the quaternization with methyl iodide as quaternization reagent so as to endow them with greater electrophoretic mobility. The cationic hybrid nanoparticles (TiO2-CHNPs) were studied by means of transmission electron microscopy (TEM), scanning electron microscopy (SEM), Fourier-transform infrared (FTIR) spectroscopy and dynamic light scattering (DLS) measurements. The results indicate that the cationic polymer is successfully grafted on the surface of the TiO2 nanoparticles. The particle size of TiO2-CHNPs is about 150 nm and the polydispersity index (PDI) is 0.307. The zeta potential, the contrast ratio of white state to dark state and response time of TiO2-CHNPs are +16.8 mV, 30 and 3 s, respectively, which show the potential application prospect in the development of electrophoretic ink.

  10. SERS of semiconducting nanoparticles (TiO{sub 2} hybrid composites).

    Energy Technology Data Exchange (ETDEWEB)

    Musumeci, A.; Gosztola, D.; Schiller, T.; Dimitrijevic, N.; Mujica, V.; Martin, D.; Rajh, T. (Center for Nanoscale Materials)

    2009-04-13

    Raman scattering of molecules adsorbed on the surface of TiO{sub 2} nanoparticles was investigated. We find strong enhancement of Raman scattering in hybrid composites that exhibit charge transfer absorption with TiO{sub 2} nanoparticles. An enhancement factor up to {approx}10{sup 3} was observed in the solutions containing TiO{sub 2} nanoparticles and biomolecules, including the important class of neurotransmitters such as dopamine and dopac (3,4-dihydroxy-phenylacetic acid). Only selected vibrations are enhanced, indicating molecular specificity due to distinct binding and orientation of the biomolecules coupled to the TiO{sub 2} surface. All enhanced modes are associated with the asymmetric vibrations of attached molecules that lower the symmetry of the charge transfer complex. The intensity and the energy of selected vibrations are dependent on the size and shape of nanoparticle support. Moreover, we show that localization of the charge in quantized nanoparticles (2 nm), demonstrated as the blue shift of particle absorption, diminishes SERS enhancement. Importantly, the smallest concentration of adsorbed molecules shows the largest Raman enhancements suggesting the possibility for high sensitivity of this system in the detection of biomolecules that form a charge transfer complex with metal oxide nanoparticles. The wavelength-dependent properties of a hybrid composite suggest a Raman resonant state. Adsorbed molecules that do not show a charge transfer complex show weak enhancements probably due to the dielectric cavity effect.

  11. Synthesis of Silver-Strontium Titanate Hybrid Nanoparticles by Sol-Gel-Hydrothermal Method

    Directory of Open Access Journals (Sweden)

    Shintaro Ueno

    2015-03-01

    Full Text Available Silver (Ag nanoparticle-loaded strontium titanate (SrTiO3 nanoparticles were attempted to be synthesized by a sol-gel-hydrothermal method. We prepared the titanium oxide precursor gels incorporated with Ag+ and Sr2+ ions with various molar ratios, and they were successfully converted into the Ag-SrTiO3 hybrid nanoparticles by the hydrothermal treatment at 230 °C in strontium hydroxide aqueous solutions. The morphology of the SrTiO3 nanoparticles is dendritic in the presence and absence of Ag+ ions. The precursor gels, which act as the high reactive precursor, give rise to high nucleation and growth rates under the hydrothermal conditions, and the resultant diffusion-limited aggregation phenomena facilitate the dendritic growth of SrTiO3. From the field-emission transmission electron microscope observation of these Ag-SrTiO3 hybrid nanoparticles, the Ag nanoparticles with a size of a few tens of nanometers are distributed without severe agglomeration, owing to the competitive formation reactions of Ag and SrTiO3.

  12. Synthesis and characterization of hybrid silica/PMMA nanoparticles and their use as filler in dental composites.

    Science.gov (United States)

    Canché-Escamilla, G; Duarte-Aranda, S; Toledano, M

    2014-09-01

    The effect of hybrid silica/poly(methylmethacrylate) (PMMA) nanoparticles on the properties of composites for dental restoration was evaluated. Hybrid nanoparticles with silica as core and PMMA as shell were obtained by a seeded emulsion polymerization process. Fourier transform infrared spectrum of the hybrid nanoparticles shows an intense peak at 1,730 cm(-1), corresponding to carbonyl groups (CO) of the ester. The thermal stability of the hybrid particles decreases with increasing amounts of PMMA and the residual mass at 700°C corresponds to the silica content in the hybrid particles. Composites were obtained by dispersing nanoparticles (silica or hybrid), as fillers, in a resin-bis glycidyl dimethacrylate (Bis-GMA)/triethylene glycol dimethacrylate (TEGDMA) (40%/60% (w/w)). The paste was then placed in a mold and polymerized under light irradiation. During the preparation of the composites, with the hybrid nanoparticles, the monomers swell the PMMA shell and after photo-curing, a semi-interpenetrating network (semi-IPN) is obtained around the silica core. The properties of the composites, obtained using the hybrid nanoparticles, depend on the filler content and the amount of PMMA in the semi-IPN matrix. For composites with similar inorganic filler contents, the composites with low amounts of PMMA shell had higher modulus than those in which silica was used as the filler.

  13. Interfacial strain and defects in asymmetric Fe-Mn oxide hybrid nanoparticles

    Science.gov (United States)

    Mayence, Arnaud; Wéry, Madeleine; Tran, Dung Trung; Wetterskog, Erik; Svedlindh, Peter; Tai, Cheuk-Wai; Bergström, Lennart

    2016-07-01

    Asymmetric Fe-Mn oxide hybrid nanoparticles have been obtained by a seed-mediated thermal decomposition-based synthesis route. The use of benzyl ether as the solvent was found to promote the orientational growth of Mn1-xO onto the iron oxide nanocube seeds yielding mainly dimers and trimers whereas 1-octadecene yields large nanoparticles. HRTEM imaging and HAADF-STEM tomography performed on dimers show that the growth of Mn1-xO occurs preferentially along the edges of iron oxide nanocubes where both oxides share a common crystallographic orientation. Fourier filtering and geometric phase analysis of dimers reveal a lattice mismatch of 5% and a large interfacial strain together with a significant concentration of defects. The saturation magnetization is lower and the coercivity is higher for the Fe-Mn oxide hybrid nanoparticles compared to the iron oxide nanocube seeds.Asymmetric Fe-Mn oxide hybrid nanoparticles have been obtained by a seed-mediated thermal decomposition-based synthesis route. The use of benzyl ether as the solvent was found to promote the orientational growth of Mn1-xO onto the iron oxide nanocube seeds yielding mainly dimers and trimers whereas 1-octadecene yields large nanoparticles. HRTEM imaging and HAADF-STEM tomography performed on dimers show that the growth of Mn1-xO occurs preferentially along the edges of iron oxide nanocubes where both oxides share a common crystallographic orientation. Fourier filtering and geometric phase analysis of dimers reveal a lattice mismatch of 5% and a large interfacial strain together with a significant concentration of defects. The saturation magnetization is lower and the coercivity is higher for the Fe-Mn oxide hybrid nanoparticles compared to the iron oxide nanocube seeds. Electronic supplementary information (ESI) available: Materials characterization, powder X-ray diffraction, EFTEM images, EELS spectra, HAADF-STEM. See DOI: 10.1039/c6nr01373b

  14. An antibacterial coating based on a polymer/sol-gel hybrid matrix loaded with silver nanoparticles

    Science.gov (United States)

    Rivero, Pedro José; Urrutia, Aitor; Goicoechea, Javier; Zamarreño, Carlos Ruiz; Arregui, Francisco Javier; Matías, Ignacio Raúl

    2011-12-01

    In this work a novel antibacterial surface composed of an organic-inorganic hybrid matrix of tetraorthosilicate and a polyelectrolyte is presented. A precursor solution of tetraethoxysilane (TEOS) and poly(acrylic acid sodium salt) (PAA) was prepared and subsequently thin films were fabricated by the dip-coating technique using glass slides as substrates. This hybrid matrix coating is further loaded with silver nanoparticles using an in situ synthesis route. The morphology and composition of the coatings have been studied using UV-VIS spectroscopy and atomic force microscopy (AFM). Energy dispersive X-ray (EDX) was also used to confirm the presence of the resulting silver nanoparticles within the thin films. Finally the coatings have been tested in bacterial cultures of genus Lactobacillus plantarum to observe their antibacterial properties. It has been experimentally demonstrated that these silver loaded organic-inorganic hybrid films have a very good antimicrobial behavior against this type of bacteria.

  15. An antibacterial coating based on a polymer/sol-gel hybrid matrix loaded with silver nanoparticles

    Directory of Open Access Journals (Sweden)

    Rivero Pedro

    2011-01-01

    Full Text Available Abstract In this work a novel antibacterial surface composed of an organic-inorganic hybrid matrix of tetraorthosilicate and a polyelectrolyte is presented. A precursor solution of tetraethoxysilane (TEOS and poly(acrylic acid sodium salt (PAA was prepared and subsequently thin films were fabricated by the dip-coating technique using glass slides as substrates. This hybrid matrix coating is further loaded with silver nanoparticles using an in situ synthesis route. The morphology and composition of the coatings have been studied using UV-VIS spectroscopy and atomic force microscopy (AFM. Energy dispersive X-ray (EDX was also used to confirm the presence of the resulting silver nanoparticles within the thin films. Finally the coatings have been tested in bacterial cultures of genus Lactobacillus plantarum to observe their antibacterial properties. It has been experimentally demonstrated that these silver loaded organic-inorganic hybrid films have a very good antimicrobial behavior against this type of bacteria.

  16. Tailored single-walled carbon nanotube--CdS nanoparticle hybrids for tunable optoelectronic devices.

    Science.gov (United States)

    Li, Xianglong; Jia, Yi; Cao, Anyuan

    2010-01-26

    The integration of organic and inorganic building blocks into novel nanohybrids is an important tool to exploit innovative materials with desirable functionalities. For this purpose, carbon nanotube--nanoparticle nanoarchitectures are intensively studied. We report here an efficient noncovalent chemical route to density-controllably and uniformly assemble single-walled carbon nanotubes with CdS nanoparticles. The methodology not only promises the resulting hybrids will be solution-processable but also endows the hybrids with distinct optoelectronic properties including tunable photoresponse mediated by amine molecules. On the basis of these merits, reliable thin-film photoswitches and light-driven chemical sensors are demonstrated, which highlights the potential of tailored hybrids in the development of new tunable optoelectronic devices and sensors.

  17. Capillary-force-induced formation of luminescent polystyrene/(rare-earth-doped nanoparticle) hybrid hollow spheres.

    Science.gov (United States)

    Chen, Min; Xie, Lin; Li, Fuyou; Zhou, Shuxue; Wu, Limin

    2010-10-01

    This paper presents a "one-pot" procedure to synthesize polystyrene/(rare-earth-doped nanoparticles) (PS/REDNPs) hybrid hollow spheres via the in situ diffusion of organic core into inorganic shell under strong capillary force. In this approach, when carboxyl-capped PS colloids were deposited by different REDNPs in aqueous medium, such as LaF3:Eu3+, LaF3:Ce3+-Tb3+, and YVO4:Dy3+, PS/REDNPs inorganic-organic hybrid hollow spheres could be directly obtained via the in situ diffusion of core PS chains into the voids between rare-earth-doped nanoparticles through the strong capillary force. Not only is the synthetic procedure versatile and very simple, but also the obtained hybrid hollow spheres are hydrophilic and luminescent and could be directly used in chemical and biological fields.

  18. Biocompatible and colloidally stabilized mPEG-PE/calcium phosphate hybrid nanoparticles loaded with siRNAs targeting tumors.

    Science.gov (United States)

    Gao, Pei; Zhang, Xiangyu; Wang, Hongzhi; Zhang, Qinghong; Li, He; Li, Yaogang; Duan, Yourong

    2016-01-19

    Calcium phosphate nanoparticles are safe and effective delivery vehicles for small interfering RNA (siRNA), as a result of their excellent biocompatibility. In this work, mPEG-PE (polyethylene glycol-L-α-phosphatidylethanolamine) was synthesized and used to prepare nanoparticles composed of mPEG-PE and calcium phosphate for siRNA delivery. Calcium phosphate and mPEG-PE formed the stable hybrid nanoparticles through self-assembly resulting from electrostatic interaction in water. The average size of the hybrid nanoparticles was approximately 53.2 nm with a negative charge of approximately -16.7 mV, which was confirmed by dynamic light scattering (DLS) measurements. The nanoparticles exhibited excellent stability in serum and could protect siRNA from ribonuclease (RNase) degradation. The cellular internalization of siRNA-loaded nanoparticles was evaluated in SMMC-7721 cells using a laser scanning confocal microscope (CLSM) and flow cytometry. The hybrid nanoparticles could efficiently deliver siRNA to cells compared with free siRNA. Moreover, the in vivo distribution of Cy5-siRNA-loaded hybrid nanoparticles was observed after being injected into tumor-bearing nude mice. The nanoparticles concentrated in the tumor regions through an enhanced permeability and retention (EPR) effect based on the fluorescence intensities of tissue distribution. A safety evaluation of the nanoparticles was performed both in vitro and in vivo demonstrating that the hybrid nanoparticle delivery system had almost no toxicity. These results indicated that the mPEG-PE/CaP hybrid nanoparticles could be a stable, safe and promising siRNA nanocarrier for anticancer therapy.

  19. Thermodynamics of the hybrid interaction of hydrogen with palladium nanoparticles.

    Science.gov (United States)

    Griessen, Ronald; Strohfeldt, Nikolai; Giessen, Harald

    2016-03-01

    Palladium-hydrogen is a prototypical metal-hydrogen system. It is therefore not at all surprising that a lot of attention has been devoted to the absorption and desorption of hydrogen in nanosized palladium particles. Several seminal articles on the interaction of H with Pd nanocubes and nanoparticles have recently been published. Although each article provides for the first time detailed data on specific aspects of hydrogen in nanoparticles, they individually do not contain enough information to draw firm conclusions about the involved mechanisms. Here, we show that the large body of data available so far in literature exhibits general patterns that lead to unambiguous conclusions about the processes involved in H absorption and desorption in Pd nanoparticles. On the basis of a remarkably robust scaling law for the hysteresis in absorption-desorption isotherms, we show that hydrogen absorption in palladium nanoparticles is consistent with a coherent interface model and is thus clearly different from bulk Pd behaviour. However, H desorption occurs fully coherently only for small nanoparticles (typically smaller than 50 nm) at temperatures sufficiently close to the critical temperature. For larger particles it is partially incoherent, as in bulk, where dilute α-PdHx and high concentration β-PdHx phases coexist. PMID:26569476

  20. Thermodynamics of the hybrid interaction of hydrogen with palladium nanoparticles.

    Science.gov (United States)

    Griessen, Ronald; Strohfeldt, Nikolai; Giessen, Harald

    2016-03-01

    Palladium-hydrogen is a prototypical metal-hydrogen system. It is therefore not at all surprising that a lot of attention has been devoted to the absorption and desorption of hydrogen in nanosized palladium particles. Several seminal articles on the interaction of H with Pd nanocubes and nanoparticles have recently been published. Although each article provides for the first time detailed data on specific aspects of hydrogen in nanoparticles, they individually do not contain enough information to draw firm conclusions about the involved mechanisms. Here, we show that the large body of data available so far in literature exhibits general patterns that lead to unambiguous conclusions about the processes involved in H absorption and desorption in Pd nanoparticles. On the basis of a remarkably robust scaling law for the hysteresis in absorption-desorption isotherms, we show that hydrogen absorption in palladium nanoparticles is consistent with a coherent interface model and is thus clearly different from bulk Pd behaviour. However, H desorption occurs fully coherently only for small nanoparticles (typically smaller than 50 nm) at temperatures sufficiently close to the critical temperature. For larger particles it is partially incoherent, as in bulk, where dilute α-PdHx and high concentration β-PdHx phases coexist.

  1. Gold nanoparticles embedded in organic/inorganic hybrid matrix: electrical and electrochemical behavior (withdrawal notice)

    Science.gov (United States)

    Moreira, Sandra D. F. C.; Silva, J. P. B.; Silva, Carlos J. R.; Capan, I.; Gomes, M. J. M.; Costa, Manuel F. M.

    2013-05-01

    Gold nanoparticles (AuNPs) with different diameters, from 3 to 32 nm, were immobilized in amine-alcohol-silicate matrix by mixing a preformed nanoparticle colloid with the precursors of amine-alcohol-silicate (AAs) prior to the solgel transition. These nanocomposites show high optical quality and optical features dictated by the size of the nanoparticle dopants but also present a high degree of flexibility which can largely enhance the range of practical applications. The current-voltage, impedance and capacitance-voltage characteristics of these materials have been measured. The electrochemical and impedimetric results reveal that AuNPs with different sizes give different signals, thus providing useful information that allows the employment of AuNPs in electrochemical biosensors. Capacitance- voltage measurements showed that these composites embedded AuNPs exhibited a large hysteresis window of 2.4V which indicates the possibility of charge storage in the Au nanoparticles embedded AAs hybrids.

  2. Solubility studies of inorganic–organic hybrid nanoparticle photoresists with different surface functional groups

    KAUST Repository

    Li, Li

    2016-01-01

    © 2016 The Royal Society of Chemistry. The solubility behavior of Hf and Zr based hybrid nanoparticles with different surface ligands in different concentrations of photoacid generator as potential EUV photoresists was investigated in detail. The nanoparticles regardless of core or ligand chemistry have a hydrodynamic diameter of 2-3 nm and a very narrow size distribution in organic solvents. The Hansen solubility parameters for nanoparticles functionalized with IBA and 2MBA have the highest contribution from the dispersion interaction than those with tDMA and MAA, which show more polar character. The nanoparticles functionalized with unsaturated surface ligands showed more apparent solubility changes after exposure to DUV than those with saturated ones. The solubility differences after exposure are more pronounced for films containing a higher amount of photoacid generator. The work reported here provides material selection criteria and processing strategies for the design of high performance EUV photoresists.

  3. Solubility studies of inorganic-organic hybrid nanoparticle photoresists with different surface functional groups.

    Science.gov (United States)

    Li, Li; Chakrabarty, Souvik; Jiang, Jing; Zhang, Ben; Ober, Christopher; Giannelis, Emmanuel P

    2016-01-21

    The solubility behavior of Hf and Zr based hybrid nanoparticles with different surface ligands in different concentrations of photoacid generator as potential EUV photoresists was investigated in detail. The nanoparticles regardless of core or ligand chemistry have a hydrodynamic diameter of 2-3 nm and a very narrow size distribution in organic solvents. The Hansen solubility parameters for nanoparticles functionalized with IBA and 2MBA have the highest contribution from the dispersion interaction than those with tDMA and MAA, which show more polar character. The nanoparticles functionalized with unsaturated surface ligands showed more apparent solubility changes after exposure to DUV than those with saturated ones. The solubility differences after exposure are more pronounced for films containing a higher amount of photoacid generator. The work reported here provides material selection criteria and processing strategies for the design of high performance EUV photoresists. PMID:26695121

  4. Tensile Mechanical Properties and Strengthening Mechanism of Hybrid Carbon Nanotube and Silicon Carbide Nanoparticle-Reinforced Magnesium Alloy Composites

    OpenAIRE

    Xia Zhou; Depeng Su; Chengwei Wu; Liming Liu

    2012-01-01

    AZ91 magnesium alloy hybrid composites reinforced with different hybrid ratios of carbon nanotubes (CNTs) and silicon carbide (SiC) nanoparticulates were fabricated by semisolid stirring assisted ultrasonic cavitation. The results showed that grains of the matrix in the AZ91/(CNT + SiC) composites were obviously refined after adding hybrid CNTs and SiC nanoparticles to the AZ91 alloy, and the room-temperature mechanical properties of AZ91/(CNT + SiC) hybrid composites were improved comparing ...

  5. Dispersible lanthanide organic hybrid nanoparticles: synthesis, morphology and application.

    Science.gov (United States)

    Zhou, Xia; Ling, Jun; Sun, Weilin; Shen, Zhiquan

    2016-06-21

    Novel nanoparticles of coordination polymers (CPs) with various morphologies are successfully prepared. The obtained products can be well-dispersed to make films on glass substrates by the colloidal deposition method and introduced into methyl cellulose to produce transparent and luminescent films.

  6. A highly conductive, non-flammable polymer–nanoparticle hybrid electrolyte

    KAUST Repository

    Agrawal, Akanksha

    2015-01-01

    © 2015 The Royal Society of Chemistry. We report on the physical properties of lithium-ion conducting nanoparticle-polymer hybrid electrolytes created by dispersing bidisperse mixtures of polyethylene glycol (PEG)-functionalized silica nanoparticles in an aprotic liquid host. At high particle contents, we find that the ionic conductivity is a non-monotonic function of the fraction of larger particles xL in the mixtures, and that for the nearly symmetric case xL ≈ 0.5 (i.e. equal volume fraction of small and large particles), the room temperature ionic conductivity is nearly ten-times larger than in similar nanoparticle hybrid electrolytes comprised of the pure small (xL ≈ 0) or large (xL ≈ 1) particle components. Complementary trends are seen in the activation energy for ion migration and effective tortuosity of the electrolytes, which both exhibit minima near xL ≈ 0.5. Characterization of the electrolytes by dynamic rheology reveals that the maximum conductivity coincides with a distinct transition in soft glassy properties from a jammed to partially jammed and back to jammed state, as the fraction of large particles is increased from 0 to 1. This finding implies that the conductivity enhancement arises from purely entropic loss of correlation between nanoparticle centers arising from particle size dispersity. As a consequence of these physics, it is now possible to create hybrid electrolytes with MPa elastic moduli and mS cm-1 ionic conductivity levels at room temperature using common aprotic liquid media as the electrolyte solvent. Remarkably, we also find that even in highly flammable liquid media, the bidisperse nanoparticle hybrid electrolytes can be formulated to exhibit low or no flammability without compromising their favorable room temperature ionic conductivity and mechanical properties.

  7. Fabrication of molecular hybrid films of gold nanoparticle and polythiophene by covalent assembly

    Energy Technology Data Exchange (ETDEWEB)

    Sundaramurthy, Jayaraman, E-mail: jsu2@np.edu.sg [Department of Chemical & Biomolecular Engineering, National University of Singapore, Block E5, 4 Engineering Drive 4, 117576 (Singapore); Environmental & Water Technology Centre of Innovation, Ngee Ann Polytechnic, 599489 (Singapore); Dharmarajan, Rajarathnam [CERAR, University of South Australia, Mawson Lakes, SA 5095 (Australia); Srinivasan, M.P., E-mail: chesmp@nus.edu.sg [Department of Chemical & Biomolecular Engineering, National University of Singapore, Block E5, 4 Engineering Drive 4, 117576 (Singapore)

    2015-08-31

    This work demonstrates the fabrication of molecular hybrid films comprising gold nanoparticles (AuNPs) incorporated in covalently assembled, substituted polythiophene (poly(3-(2-bromoethoxy)ethoxymethylthiophene-2,5-diyl (PBrEEMT))) films by different surface chemistry routes. AuNPs are incorporated in the immobilized polythiophene matrix due to its affinity for amine and sulfur. The amount of AuNPs present depends on the nature of the incorporation, the extent of film coverage and interaction of thiophene and amine groups. PBrEEMT films functionalized with amine rich polyallylamine immobilize greater numbers of AuNPs due to more extensive gold–amine interactions. Covalent binding between AuNP and PBrEEMT films was accomplished by using pre-functionalised AuNPs (4-aminothiophenol functionalized AuNPs). Atomic force microscopy, field emission scanning electron microscopy and X-ray photoelectron spectroscopy were used to study the morphology and chemical constituents of assembled films. These approaches will pave the way for developing facile methods for nanoparticle incorporation and will also facilitate direct interaction of nanoparticles with the conducting polymer matrix and enhance the electrical properties of the films. - Highlights: • Covalent molecular assembly enabled the fabrication of molecular hybrid films. • Monomeric and polymeric species were employed as intermediate linkers. • Adopted approaches facilitated the direct interaction of gold nanoparticle in films. • The amount of nanoparticle incorporation depended on the extent of film coverage.

  8. Fabrication of molecular hybrid films of gold nanoparticle and polythiophene by covalent assembly

    International Nuclear Information System (INIS)

    This work demonstrates the fabrication of molecular hybrid films comprising gold nanoparticles (AuNPs) incorporated in covalently assembled, substituted polythiophene (poly(3-(2-bromoethoxy)ethoxymethylthiophene-2,5-diyl (PBrEEMT))) films by different surface chemistry routes. AuNPs are incorporated in the immobilized polythiophene matrix due to its affinity for amine and sulfur. The amount of AuNPs present depends on the nature of the incorporation, the extent of film coverage and interaction of thiophene and amine groups. PBrEEMT films functionalized with amine rich polyallylamine immobilize greater numbers of AuNPs due to more extensive gold–amine interactions. Covalent binding between AuNP and PBrEEMT films was accomplished by using pre-functionalised AuNPs (4-aminothiophenol functionalized AuNPs). Atomic force microscopy, field emission scanning electron microscopy and X-ray photoelectron spectroscopy were used to study the morphology and chemical constituents of assembled films. These approaches will pave the way for developing facile methods for nanoparticle incorporation and will also facilitate direct interaction of nanoparticles with the conducting polymer matrix and enhance the electrical properties of the films. - Highlights: • Covalent molecular assembly enabled the fabrication of molecular hybrid films. • Monomeric and polymeric species were employed as intermediate linkers. • Adopted approaches facilitated the direct interaction of gold nanoparticle in films. • The amount of nanoparticle incorporation depended on the extent of film coverage

  9. Hybridization and the origin of Fano resonances in symmetric nanoparticle trimers

    Science.gov (United States)

    Hopkins, Ben; Filonov, Dmitry S.; Glybovski, Stanislav B.; Miroshnichenko, Andrey E.

    2015-07-01

    We study the light scattering by plasmonic and dielectric symmetric trimers to investigate the existence of polarization-independent Fano resonances. Plasmonic hybridization theory is revealed to hide simple physics, and we instead provide a simplified model for hybridization to derive a plasmonic trimer's eigenmodes analytically. This approach is demonstrated to accurately recreate full wave simulations of plasmonic trimers and their Fano resonances. We are subsequently able to deduce the grounds for modal interference in plasmonic trimers and the related formation of Fano resonances. However, by generalizing our simplified hybridization approach, we are also able to investigate the eigenmodes of all-dielectric trimers. We show that bianisotropic coupling channels between high-index dielectric nanoparticles are able to increase the capacity for Fano resonances, even at normal incidence. We finally provide the first experimental measurements of sharp, polarization-independent Fano resonances from a symmetric all-dielectric trimer, with very good agreement with the predicted response from our simplified hybridization theory.

  10. Preparation of well-defined polystyrene/silica hybrid nanoparticles by ATRP

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    Immobilization of the atom transfer radical polymerization(ATRP)macroinitiators at the silica nanoparticle surfaces was achieved through surface modification with excess toluene-2,4-diisocynate(TDI),after which the residual isocyanate groups were converted into ATRP macroinitiators.Structurally well-defined polystyrene chains were grown from the nanoparticle surfaces to yield individual particles composed of a silica core and a well-defined,densely grafted outer polystyrene by ATRP,which was initiated by the as-synthesized silica-based macroinitiator.FTIR,NMR and gel permeation chromatography(GPC)were used to characterize the polystyrene/silica hybrid particles.

  11. Preparation of well-defined polystyrene/silica hybrid nanoparticles by ATRP

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    Immobilization of the atom transfer radical polymerization (ATRP) macroinitiators at the silica nanoparticle surfaces was achieved through surface modification with excess toluene-2,4-diisocynate (TDI), after which the residual isocyanate groups were converted into ATRP macroinitiators. Structurally well-defined polystyrene chains were grown from the nanoparticle surfaces to yield individual particles composed of a silica core and a well-defined, densely grafted outer polystyrene by ATRP, which was initiated by the as-synthesized silica-based macroinitiator. FTIR, NMR and gel permeation chro-matography (GPC) were used to characterize the polystyrene/silica hybrid particles.

  12. A simple approach to obtain hybrid Au-loaded polymeric nanoparticles with a tunable metal load

    Science.gov (United States)

    Luque-Michel, Edurne; Larrea, Ane; Lahuerta, Celia; Sebastian, Víctor; Imbuluzqueta, Edurne; Arruebo, Manuel; Blanco-Prieto, María J.; Santamaría, Jesús

    2016-03-01

    A new strategy to nanoengineer multi-functional polymer-metal hybrid nanostructures is reported. By using this protocol the hurdles of most of the current developments concerning covalent and non-covalent attachment of polymers to preformed inorganic nanoparticles (NPs) are overcome. The strategy is based on the in situ reduction of metal precursors using the polymeric nanoparticle as a nanoreactor. Gold nanoparticles and poly(dl-lactic-co-glycolic acid), PLGA, are located in the core and shell, respectively. This novel technique enables the production of PLGA NPs smaller than 200 nm that bear either a single encapsulated Au NP or several smaller NPs with tunable sizes and a 100% loading efficiency. In situ reduction of Au ions inside the polymeric NPs was achieved on demand by using heat to activate the reductive effect of citrate ions. In addition, we show that the loading of the resulting Au NPs inside the PLGA NPs is highly dependent on the surfactant used. Electron microscopy, laser irradiation, UV-Vis and fluorescence spectroscopy characterization techniques confirm the location of Au nanoparticles. These promising results indicate that these hybrid nanomaterials could be used in theranostic applications or as contrast agents in dark-field imaging and computed tomography.A new strategy to nanoengineer multi-functional polymer-metal hybrid nanostructures is reported. By using this protocol the hurdles of most of the current developments concerning covalent and non-covalent attachment of polymers to preformed inorganic nanoparticles (NPs) are overcome. The strategy is based on the in situ reduction of metal precursors using the polymeric nanoparticle as a nanoreactor. Gold nanoparticles and poly(dl-lactic-co-glycolic acid), PLGA, are located in the core and shell, respectively. This novel technique enables the production of PLGA NPs smaller than 200 nm that bear either a single encapsulated Au NP or several smaller NPs with tunable sizes and a 100% loading

  13. Synthesis of Hybrid SiC/SiO2 Nanoparticles and Their Polymer Nanocomposites

    Science.gov (United States)

    Hassan, Tarig A.; Rangari, Vijaya K.; Baker, Fredric; Jeelani, Shaik

    2013-04-01

    In the present investigation, silicon carbide (β-SiC) nanoparticles ( 30 nm) were coated on silicon dioxide (SiO2) nanoparticles ( 200 nm) using sonochemical method. The resultant hybrid nanoparticles were then infused into SC-15 epoxy resin to enhance the thermal and mechanical properties of SC-15 epoxy for structural application. To fabricate an epoxy-based nanocomposite containing SiC/SiO2 hybrid nanoparticles, we have opted a two-step process. In the first step, the silica nanoparticles were coated with SiC nanoparticles using high intensity ultrasonic irradiation. In a second step, 1 wt.% of as-prepared SiC/SiO2 particles were dispersed in epoxy part-A (diglycidylether of bisphenol A) using a high intensity ultrasound for 30 min at 5°C. The part-B (cycloaliphatic amine hardener) of the epoxy was then mixed with part-A-SiC/SiO2 mixture using a high-speed mechanical stirrer for 10 min. The SiC/SiO2/epoxy resin mixture was cured at room temperature for 24 h. The SiC nanoparticles coating on SiO2 was characterized using X-ray diffraction (XRD) and high resolution transmission electron microscope (TEM). The as-prepared nanocomposite samples were characterized using thermo gravimetric analysis (TGA) and differential scanning calorimeter (DSC). Compression tests have been carried out for both nanocomposite and neat epoxy systems. The results indicated that 1 wt.% (SiC) + (SiO2) loading derived improvements in both thermal and mechanical properties when compared to the neat epoxy system.

  14. Immune Stimulating Photoactive Hybrid Nanoparticles for Metastatic Breast Cancer†

    OpenAIRE

    Marrache, Sean; Choi, Joshua H.; Tundup, Smanla; Zaver, Dillon; Harn, Donald A.; Dhar, Shanta

    2013-01-01

    A therapeutic technology that combines the phototoxic and immune-stimulating ability of photodynamic therapy (PDT) with the widespread effectiveness of the immune system can be very promising to treat metastatic breast cancer. We speculated that the knowledge of molecular mechanisms of existing multi-component therapies could provide clues to aid the discovery of new combinations of an immunostimulant with a photosensitizer (PS) using a nanoparticle (NP) delivery platform. Therapeutic challen...

  15. Improved photovoltaic performance of silicon nanowire/organic hybrid solar cells by incorporating silver nanoparticles.

    Science.gov (United States)

    Liu, Kong; Qu, Shengchun; Zhang, Xinhui; Tan, Furui; Wang, Zhanguo

    2013-02-18

    Silicon nanowire (SiNW) arrays show an excellent light-trapping characteristic and high mobility for carriers. Surface plasmon resonance of silver nanoparticles (AgNPs) can be used to increase light scattering and absorption in solar cells. We fabricated a new kind of SiNW/organic hybrid solar cell by introducing AgNPs. Reflection spectra confirm the improved light scattering of AgNP-decorated SiNW arrays. A double-junction tandem structure was designed to manufacture our hybrid cells. Both short-circuit current and external quantum efficiency measurements show an enhancement in optical absorption of organic layer, especially at lower wavelengths.

  16. Population Dynamics and the Optical Absorption in Hybrid Metal Nanoparticle - Semiconductor Quantum dot Nanosystem

    CERN Document Server

    Kim, Nam-Chol; Ko, Myong-Chol; So, Guang Hyok; Kim, Il-Guang

    2015-01-01

    We studied theoretically the population dynamics and the absorption spectrum of hybrid nanosystem consisted of a matal nanoparticle (MNP) and a semiconductor quantum dot(SQD). We investigated the exciton-plasmon coupling effects on the population dynamics and the absorption properties of the nanostructure. Our results show that the nonlinear optical response of the hybrid nanosystem can be greatly enhanced or depressed due to the exciton-plasmon couplings. The results obtained here may have the potential applications of nanoscale optical devices such as optical switches and quantum devices such as a single photon transistor.

  17. Surface plasmon-assisted optical bistability in the quantum dot-metal nanoparticle hybrid system

    Science.gov (United States)

    Bao, Chengjun; Qi, Yihong; Niu, Yueping; Gong, Shangqing

    2016-07-01

    We theoretically investigated optical bistability (OB) of a coupled excition-plasmon hybrid system in a unidirectional ring cavity. It is found that the threshold and the region of OB can be tuned by adjusting the center-center distance between the quantum dot and metal nanoparticle (MNP), the Rabi frequency of the control field and the radius of the MNP. Due to the significantly enhanced optical nonlinearity by the surface plasmon effect, the threshold of OB can be decreased greatly when the probe field is parallel to the major axis of the hybrid system. The enhanced OB may have promising applications in optical switching and optical storage.

  18. EPR characterisation of platinum nanoparticle functionalised carbon nanotube hybrid materials.

    Science.gov (United States)

    Dennany, Lynn; Sherrell, Peter; Chen, Jun; Innis, Peter C; Wallace, Gordon G; Minett, Andrew I

    2010-04-28

    The use of nanostructured carbon materials as electrodes for energy storage and conversion is an expanding area of research in recent years. Herein, platinum nanoparticles have been deposited onto both multi-walled and single-walled carbon nanotubes (CNTs) via a microwave assisted polyol reduction method. This interaction has been probed with electron paramagnetic resonance (EPR) and Raman spectroscopies to elucidate the charge/electron transfer interactions between the Pt nanoparticles and the CNTs. Observed shifts in the g factors of the CNTs are indicative of such an electronic interaction, strongly suggesting the covalent attachment of the nanoparticles to the carboxylic groups on the CNTs, formed during the microwave-assisted reduction process. The Pt decorated CNTs show a dramatic increase in electrochemical behaviour in terms of high reversible capacity and relatively stable cycle performance compared to unmodified CNTs increasing their applicability in energy storage devices. For instance, significant increases in the electrochemical double layer capacitance are observed for the CNT-NP composite electrode. PMID:20379504

  19. Exciton-plasmon Coupling and Electromagnetically Induced Transparency in Monolayer Semiconductors Hybridized with Ag Nanoparticles

    CERN Document Server

    Weijie, Zhao; Bo, Liu; Ivan, Verzhbitskiy; Shisheng, Li; Francesco, Giustiniano; Daichi, Kozawa; Ping, Loh Kian; Kazunari, Matsuda; Koichi, Okamoto; Rupert, Oulton F; Goki, Eda

    2016-01-01

    Hybrid systems of excitons strongly coupled to localized surface plasmons supported by metallic nanoparticles define a new approach to control light-matter interactions. Here, we report exciton-plasmon coupling in two-dimensional (2D) semiconductors, such as MoS2 and WS2, hybridized with silver nanoparticles. Prominent photoluminescence enhancement in monolayer MoS2 was observed with localized surface plasmon resonance (LSPR) tuned to the exciton resonance. By tuning the excitation energy, the contributions from near field enhancement and radiative emission rate enhancement via Purcell effect were resolved. Strong coherent dipole-dipole coupling between excitons and LSPR in resonant condition manifests as an electromagnetically induced transparency window in the extinction spectra of the localized surface plasmon. In this strong coupling regime a new quasi-particle, known as a plexciton, is expected to exhibit distinct properties, which exist in neither of the original particles. Our results demonstrate that ...

  20. Targeted lipid–polyaniline hybrid nanoparticles for photoacoustic imaging guided photothermal therapy of cancer

    Science.gov (United States)

    Wang, Jinping; Yan, Ran; Guo, Fang; Yu, Meng; Tan, Fengping; Li, Nan

    2016-07-01

    Designing a targeted and versatile photothermal agent for the integration of precise diagnosis and effective photothermal treatment of tumors is desirable but remains a great challenge. In this study, folic acid ligand conjugated lipid-coated polyaniline hybrid nanoparticles (FA–Lipid–PANI NPs) were successfully fabricated by a distinctive technology. The obtained hybrid FA–Lipid–PANI NPs with small size exhibited not only significant photoacoustic (PA) imaging signals, but also a remarkable photothermal effect for tumor treatment. With PA imaging and photothermal therapy (PTT), the tumor could be accurately positioned and thoroughly eradicated in vivo after intravenous injection of FA–Lipid–PANI NPs. These multifunctional nanoparticles could play an important role in simultaneously facilitating imaging and PTT to achieve better therapeutic efficacy.

  1. Targeted lipid-polyaniline hybrid nanoparticles for photoacoustic imaging guided photothermal therapy of cancer

    Science.gov (United States)

    Wang, Jinping; Yan, Ran; Guo, Fang; Yu, Meng; Tan, Fengping; Li, Nan

    2016-07-01

    Designing a targeted and versatile photothermal agent for the integration of precise diagnosis and effective photothermal treatment of tumors is desirable but remains a great challenge. In this study, folic acid ligand conjugated lipid-coated polyaniline hybrid nanoparticles (FA-Lipid-PANI NPs) were successfully fabricated by a distinctive technology. The obtained hybrid FA-Lipid-PANI NPs with small size exhibited not only significant photoacoustic (PA) imaging signals, but also a remarkable photothermal effect for tumor treatment. With PA imaging and photothermal therapy (PTT), the tumor could be accurately positioned and thoroughly eradicated in vivo after intravenous injection of FA-Lipid-PANI NPs. These multifunctional nanoparticles could play an important role in simultaneously facilitating imaging and PTT to achieve better therapeutic efficacy.

  2. A Simple Method for Forming Hybrid Core-Shell Nanoparticles Suspended in Water

    Directory of Open Access Journals (Sweden)

    Jean-Christophe Daigle

    2008-01-01

    addition fragmentation chain transfer (RAFT polymerization as dispersant. Then, the resulting dispersion is engaged in a radical emulsion polymerization process whereby a hydrophobic organic monomer (styrene and butyl acrylate is polymerized to form the shell of the hybrid nanoparticle. This method is extremely versatile, allowing the preparation of a variety of nanocomposites with metal oxides (alumina, rutile, anatase, barium titanate, zirconia, copper oxide, metals (Mo, Zn, and even inorganic nitrides (Si3N4.

  3. Engineered Protein Polymer-Gold Nanoparticle Hybrid Materials for Small Molecule Delivery

    OpenAIRE

    Dai, Min; Frezzo, JA; SHARMA, E.; Chen, R.; Singh, N.; Yuvienco, C; Caglar, E; Xiao, S; Saxena, A.; Montclare, JK

    2016-01-01

    We have fabricated protein polymer-gold nanoparticle (P-GNP) nanocomposites that exhibit enhanced binding and delivery properties of the small hydrophobic molecule drug, curcumin, to the model breast cancer cell line, MCF-7. These hybrid biomaterials are constructed via in situ GNP templated-synthesis with genetically engineered histidine tags. The P-GNP nanocomposites exhibit enhanced small molecule loading, sustained release and increased uptake by MCF-7 cells. When compared to the proteins...

  4. Evaluation of hybrid sol-gel incorporated with nanoparticles as nano paint

    Science.gov (United States)

    Jameel, Zainab N.; Haider, Adawiya J.; Taha, Samar Y.; Gangopadhyay, Shubhra; Bok, Sangho

    2016-07-01

    A coating with self-cleaning characteristics has been developed using a TiO2/SiO2 hybrid sol-gel, TiO2 nanoparticles and organosilicate nanoparticles (OSNP). A patented technology of the hybrid sol-gel and OSNP was combined with TiO2 nanoparticles to create the surface chemistry for self-cleaning. Two synthesis methods have been developed to prepare TiO2 nanoparticles (NPs), resulting in the enhancement of local paint by the addition of anatase and rutile TiO2 phases. The NPs size as determined by Dynamic Light Scattering (DLS) ranges within of (3-4) and (20-42) nm, which was also confirmed by Scanning Electron Microscopy (SEM). The nanoparticles showed surface charge (zeta-potential, ζ) of +35 and +25.62 mV for the methods, respectively, and ζ values of +41.31 and 34.02 mV for anatase and rutile phases, respectively. The NPs were mixed with the coating solution (i.e., hybrid sol-gel and OSNP) in different concentrations and thin films were prepared by spin coating. Self-cleaning tests were performed using Rhodamine B (RhB) as a pollution indicator. The effect of UV-irradiation on the films was also studied. Anatase and rutile incorporated as a mixture with different ratios in local paint and washability as well as a contrast ratio tests were performed. It was found that the addition of TiO2 NPs in combination with irradiation show a great enhancement of RhB degradation (1%) wt. with a decrease in contact angle and improved washability.

  5. Ionic-liquid-nanoparticle hybrid electrolytes: applications in lithium metal batteries.

    Science.gov (United States)

    Lu, Yingying; Korf, Kevin; Kambe, Yu; Tu, Zhengyuan; Archer, Lynden A

    2014-01-01

    Development of rechargeable lithium metal battery (LMB) remains a challenge because of uneven lithium deposition during repeated cycles of charge and discharge. Ionic liquids have received intensive scientific interest as electrolytes because of their exceptional thermal and electrochemical stabilities. Ionic liquid and ionic-liquid-nanoparticle hybrid electrolytes based on 1-methy-3-propylimidazolium (IM) and 1-methy-3-propylpiperidinium (PP) have been synthesized and their ionic conductivity, electrochemical stability, mechanical properties, and ability to promote stable Li electrodeposition investigated. PP-based electrolytes were found to be more conductive and substantially more efficient in suppressing dendrite formation on cycled lithium anodes; as little as 11 wt % PP-IL in a PC-LiTFSI host produces more than a ten-fold increase in cell lifetime. Both PP- and IM-based nanoparticle hybrid electrolytes provide up to 10 000-fold improvements in cell lifetime than anticipated based on their mechanical modulus alone. Galvanostatic cycling measurements in Li/Li4 Ti5 O12 half cells using IL-nanoparticle hybrid electrolytes reveal more than 500 cycles of trouble-free operation and enhanced rate capability. PMID:24282090

  6. Core shell hybrids based on noble metal nanoparticles and conjugated polymers: synthesis and characterization

    Directory of Open Access Journals (Sweden)

    Battocchio Chiara

    2011-01-01

    Full Text Available Abstract Noble metal nanoparticles of different sizes and shapes combined with conjugated functional polymers give rise to advanced core shell hybrids with interesting physical characteristics and potential applications in sensors or cancer therapy. In this paper, a versatile and facile synthesis of core shell systems based on noble metal nanoparticles (AuNPs, AgNPs, PtNPs, coated by copolymers belonging to the class of substituted polyacetylenes has been developed. The polymeric shells containing functionalities such as phenyl, ammonium, or thiol pending groups have been chosen in order to tune hydrophilic and hydrophobic properties and solubility of the target core shell hybrids. The Au, Ag, or Pt nanoparticles coated by poly(dimethylpropargylamonium chloride, or poly(phenylacetylene-co-allylmercaptan. The chemical structure of polymeric shell, size and size distribution and optical properties of hybrids have been assessed. The mean diameter of the metal core has been measured (about 10-30 nm with polymeric shell of about 2 nm.

  7. Resistive Switching Characteristics of Tantalum Oxide Thin Film and Titanium Oxide Nanoparticles Hybrid Structure.

    Science.gov (United States)

    Park, Mi Ra; Abbas, Yawar; Hu, Quanli; Yoon, Tae-Sik; Choi, Young Jin; Kang, Chi Jung

    2015-11-01

    The fabrication of hybrid structure with TiO2 nanoparticle assembly and Ta2O5 thin film layer was demonstrated. The close-packed nanoparticles could influence the resistive switching behaviors due to the huge numbers of interface states and vacancies in the nanoparticle assembly. The device with hybrid structure presented the typical bipolar resistive switching characteristics in the structure of Ti/TiO2/Ta2O5/Au on SiO2/Si substrate. The set voltage was observed at -0.7 V, and the reset voltage occurred at (-)-0.7 V, which was smaller than that of Ta2O5 layer only. The electrical conduction mechanisms were the ohmic conduction at low resistance state (LRS) and the space charge limited conduction at high resistance state (HRS), respectively. The devices showed stable current ratio of LRS to HRS. The temperature dependent properties of the devices were also investigated. The device with nanoparticle assembly showed better electrical characteristics with low HRS current level and stable LRS current level with respect to the temperature.

  8. Heat-induced reshaping and coarsening of metal nanoparticle-graphene oxide hybrids

    Science.gov (United States)

    Pan, Hanqing

    Glutathione-capped gold nanoparticles of size 1, 3, and 10 nm, CTAB-stabilized gold nanorods, as well as ro-carboxylate-functionalized palladium nanoparticles were synthesized and self-assembled onto graphene oxide to study their coarsening or reshaping behaviors upon heating at different temperatures ranging from 50 °C to 300 °C. These engineered nanoparticle- or nanorod-graphene oxide hybrid materials were studied by transmission electron microscopy (TEM), thermogravimetric analysis (TGA), Fourier-transform infrared (FTIR) spectroscopy, and UV-Vis spectroscopy. The spherical nanoparticles would undergo coalescence to become larger particles and the nanorods would undergo reshaping to spherical particles. UV-Vis results show that the plasmonic band of gold nanoparticles at 520 nm would shift to higher wavelength indicating the coarsening into larger particles upon heating. Transmission electron microscopy results were generally in good agreements with the UV-Vis results and would be used as a direct tool to observe the structural changes of gold nanoparticles upon heat treatments. Without the presence of graphene oxide, the nanoparticle coalescence began at the temperature between 150 and 200 °C for all three nanoparticles with different core sizes. But with the presence of graphene oxide, nanoparticles start to coalesce at the temperature below 150 °C. The gold nanorods have two plasmonic bands at ˜780 and ˜520 nm. The bands at ˜780 nm for gold nanorods would disappear when the gold nanorods-graphene oxide is heated at 50 °C indicating the complete reshaping of nanorods even at such a low temperature. Gold nanorods themselves are more stable and do not undergo the reshaping completely until the sample is heated above 150 °C. Since graphene oxide is an excellent thermal conductor, we propose that graphene oxide could transfer heat to the nanoparticles and nanorods efficiently, disrupt the interaction of stabilizing ligands, and make them to either

  9. Preparation and characterization of highly transparent epoxy/inorganic nanoparticle hybrid thin films

    Energy Technology Data Exchange (ETDEWEB)

    Yu, Yang-Yen, E-mail: yyyu@mail.mcut.edu.tw [Department of Materials Engineering, Ming Chi University of Technology, 84 Gungjuan Rd., Taishan Dist., New Taipei City 24301, Taiwan (China); Center for Thin Film Technologies and Applications, Ming Chi University of Technology, 84 Gungjuan Rd., Taishan Dist., New Taipei City 24301, Taiwan (China); Battery Research Center of Green Energy, Ming Chi University of Technology, 84 Gungjuan Rd., Taishan Dist., New Taipei City 24301, Taiwan (China); Rao, Yu-Cyuan [Department of Materials Engineering, Ming Chi University of Technology, 84 Gungjuan Rd., Taishan Dist., New Taipei City 24301, Taiwan (China); Chang, Chao-Ching [Department of Chemical and Materials Engineering, Tamkang University, 151 Yingzhuan Rd., Tamsui Dist., New Taipei City 25137, Taiwan (China)

    2013-11-01

    This paper presents the preparation of epoxy/inorganic-nanoparticle hybrid materials synthesized from diglycidyl ether of bisphenol A and colloidal titania (TiO{sub 2}) with coupling agent, 3-isocyanatopropyltriethoxysilane, and curing agent, hexahydro-4-methylphthalic anhydride, by using a thermal polymerization. The precursor was spin-coated and thermal-cured to form hybrid films. The experimental results showed that the refractive index of hybrid films can be tuned by adding various solid contents of TiO{sub 2} to hybrid films. The refractive index at 633 nm increased from 1.450 to 1.639 as the TiO{sub 2} content increased from 0 to 50 wt.%. UV–vis analysis showed that the transparency of hybrid films was over 90%. L.a.b. color analysis indicated that the luminance of films was above 95%, and no yellowing was observed. In addition, the hybrid materials exhibited a low hydroscopic property under a high-humidity environment. - Highlights: • Epoxy/titania films were prepared from colloidal titania. • Refractive index of films could be tuned by titania content. • All the prepared films had the transparency over 90%. • Luminance was above 95% and no yellowing was found. • Hydroscopic property is low at high-humidity environment.

  10. Linear Viscoelasticity of Spherical SiO 2 Nanoparticle-Tethered Poly(butyl acrylate) Hybrids

    KAUST Repository

    Goel, Vivek

    2010-12-01

    The melt state linear viscoelastic properties of spherical silica nanoparticles with grafted poly(n-butyl acrylate) chains of varying molecular weight were probed using linear small amplitude dynamic oscillatory measurements and complementary linear stress relaxation measurements. While the pure silica-tethered-polymer hybrids with no added homopolymer exhibit solid-like response, addition of matched molecular weight free matrix homopolymer chains to this hybrid, at low concentrations of added homopolymer, maintains the solid-like response with a lowered modulus that can be factored into a silica concentration dependence and a molecular weight dependence. While the silica concentration dependence of the modulus is strong, the dependence on molecular weight is weak. On the other hand, increasing the amount of added homopolymer changes the viscoelastic response to that of a liquid with a relaxation time that scales exponentially with hybrid concentration. © 2010 American Chemical Society.

  11. Tensile Mechanical Properties and Strengthening Mechanism of Hybrid Carbon Nanotube and Silicon Carbide Nanoparticle-Reinforced Magnesium Alloy Composites

    Directory of Open Access Journals (Sweden)

    Xia Zhou

    2012-01-01

    Full Text Available AZ91 magnesium alloy hybrid composites reinforced with different hybrid ratios of carbon nanotubes (CNTs and silicon carbide (SiC nanoparticulates were fabricated by semisolid stirring assisted ultrasonic cavitation. The results showed that grains of the matrix in the AZ91/(CNT + SiC composites were obviously refined after adding hybrid CNTs and SiC nanoparticles to the AZ91 alloy, and the room-temperature mechanical properties of AZ91/(CNT + SiC hybrid composites were improved comparing with the unreinforced AZ91 matrix. In addition, the tensile mechanical properties of the AZ91 alloy-based hybrid composites were considerably improved at the mass hybrid ratio of 7 : 3 for CNTs and SiC nanoparticles; in particular, the tensile and yield strength were increased, respectively, by about 45 and 55% after gravity permanent mould casting. The reason for an increase in the room-temperature strength of the hybrid composites should be mainly attributable to the larger hybrid ratio of CNTs and SiC nanoparticles, the coefficient of thermal expansion (CTE mismatch between matrix and hybrid reinforcements, the dispersive strengthening effects (Orowan strengthening, and the grain refining (Hall-Petch effect.

  12. Novel lipid hybrid albumin nanoparticle greatly lowered toxicity of pirarubicin.

    Science.gov (United States)

    Zhou, Jing; Zhang, Xuanmiao; Li, Mei; Wu, Wenqi; Sun, Xun; Zhang, Ling; Gong, Tao

    2013-10-01

    Pirarubicin (THP) is an effective anthracycline for the treatment of solid tumor. However, its potential side effects are prominent and clinical use is restricted. We aimed to develop a novel pirarubicin-oleic acid complex albumin nanoparticle (THP-OA-AN) in order to reduce the toxicity of THP. Oleic acid, human serum albumin (HSA), and egg yolk lecithin E80 was used to prepare THP-OA-AN. Prepared THP-OA-AN was characterized and animal experiments were conducted to assess its tumor suppression effect, distribution, and toxicity. Comparison between THP and THP-OA-AN showed that, with retained antitumor efficiency, the toxicity of THP-OA-AN is significantly reduced regarding bone marrow suppression, cardiotoxicity, renal toxicity, and gastrointestinal toxicity. This study developed a safe and effective formulation of THP, which has greater potential for clinic use in the tumor therapy.

  13. Platinum nanoparticle interlayer promoted improvement in photovoltaic performance of silicon/PEDOT:PSS hybrid solar cells

    Energy Technology Data Exchange (ETDEWEB)

    Bao, Xiao-Qing; Liu, L.F., E-mail: lifeng.liu@inl.int

    2015-01-15

    Inorganic–organic hybrid solar cells have attracted considerable interest in recent years for their low production cost, good mechanical flexibility and ease of processing of polymer films over a large area. Particularly, silicon/conducting polymer hybrid solar cells are extensively investigated and widely believed to be a low-cost alternative to the crystalline silicon solar cells. However, the power conversion efficiency of silicon/conducting polymer solar cells remains low in case hydrogen-terminated silicon is used. In this paper, we report that by introducing a platinum nanoparticle interlayer between the hydrogen-terminated silicon and the conducting polymer poly(3,4-ethylenedioxy thiophene):poly(styrene sulfonate), namely PEDOT:PSS, the power conversion efficiency of the resulting Si/PEDOT:PSS hybrid solar cells can be improved by a factor of 2–3. The possible mechanism responsible for the improvement has been investigated using different techniques including impedance spectroscopy, Mott–Schottky analysis and intensity modulated photocurrent/photovoltage spectroscopy (IMPS/IMVS). The results show that with a platinum nanoparticle interlayer, both the series resistance and charge transport/transfer resistance of the Si/PEDOT:PSS hybrid solar cells are reduced leading to an increased short circuit current density, and the built-in voltage at the space charge region is raised facilitating electron-hole separation. Moreover, the lifetime of charge carriers in the Si/PEDOT:PSS solar cells is extended, namely, the recombination is effectively suppressed which also contributes to the improvement of photovoltaic performance. - Graphical abstract: A platinum nanoparticle interlayer electrolessly deposited between the n-Si:H and PEDOT:PSS can markedly improve the photovoltaic performance of the resulting Si/PEDOT:PSS hybrid solar cells. - Highlights: • A Pt nanoparticle layer is introduced between the Si and PEDOT:PSS in hybrid cells. • The Pt interlayer

  14. Hybrid chitosan–Pluronic F-127 films with BaTiO{sub 3}:Co nanoparticles: Synthesis and properties

    Energy Technology Data Exchange (ETDEWEB)

    Fuentes, S., E-mail: sfuentes@ucn.cl [Departamento de Ciencias Farmacéuticas, Facultad de Ciencias, Universidad Católica del Norte, Casilla 1280, Antofagasta (Chile); Center for the Development of Nanoscience and Nanotechnology, CEDENNA, Santiago (Chile); Dubo, J. [Departamento de Ciencias Farmacéuticas, Facultad de Ciencias, Universidad Católica del Norte, Casilla 1280, Antofagasta (Chile); Barraza, N. [Departamento de Física, Facultad de Ciencias, Universidad Católica del Norte, Casilla 1280, Antofagasta (Chile); González, R. [Laboratorio de Magnetismo, Departamento de Ciencias Geológicas, Universidad Católica del Norte, Antofagasta (Chile); Veloso, E. [Dirección de Investigaciones Científicas y Tecnológicas, Pontificia Universidad Católica de Chile, Avenida Vicuña Mackenna 4860, Santiago (Chile)

    2015-03-01

    In this study, magnetic BaTiO{sub 3}:Co (BT:Co) nanoparticles prepared using a combined sol–gel–hydrothermal technique were dispersed in a chitosan/Pluronic F-127 solution (QO/Pl) to obtain a nanocomposite hybrid films. Nanoparticles and hybrid films were characterized by X-ray powder diffraction, Fourier transform infrared (FTIR) spectroscopy, scanning electron microscopy (SEM) and alternating gradient magnetometry (AGM). Experimental results indicated that the BT:Co nanoparticles were encapsulated in the QO/Pl hybrid films and that the magnetic properties of the QO/Pl/BT:Co nanocomposites are similar to the naked BT:Co nanoparticles. Results indicate that Co doping produces an enhancement in the ferromagnetic behavior of the BT nanoparticle. The coating restricts this enhancement only to low-fields, leaving the diamagnetic behavior of BT at high-fields. Magnetically stable sizes (PSD) were obtained at 3% Co doping for both naked nanoparticles and hybrid films. These show an increased magnetic memory capacity and a softer magnetic hardness with respect to non-doped BT nanoparticles. - Highlights: • We described the synthesis of magnetic BaTiO{sub 3}:Co dispersed in chitosan (QO)/Pluronic F-127 (Pl) solution by sonication to obtain nanocomposite hybrid films. • We describe the physical and magnetic properties of BaTiO{sub 3}:Co nanoparticles and QO/Pl/BT:Co hybrid films. • The magnetic properties are defines by the presence of magnetic domains. These magnetic domains are close related with the amount of Co in the host lattice. • The prepared phases could be considered as multifunctional materials, with magnetic and ferri-electrical properties, with potential uses in the design of devices.

  15. Minocycline Loaded Hybrid Composites Nanoparticles for Mesenchymal Stem Cells Differentiation into Osteogenesis

    Science.gov (United States)

    Tham, Allister Yingwei; Gandhimathi, Chinnasamy; Praveena, Jayaraman; Venugopal, Jayarama Reddy; Ramakrishna, Seeram; Kumar, Srinivasan Dinesh

    2016-01-01

    Bone transplants are used to treat fractures and increase new tissue development in bone tissue engineering. Grafting of massive implantations showing slow curing rate and results in cell death for poor vascularization. The potentials of biocomposite scaffolds to mimic extracellular matrix (ECM) and including new biomaterials could produce a better substitute for new bone tissue formation. A purpose of this study is to analyze polycaprolactone/silk fibroin/hyaluronic acid/minocycline hydrochloride (PCL/SF/HA/MH) nanoparticles initiate human mesenchymal stem cells (MSCs) proliferation and differentiation into osteogenesis. Electrospraying technique was used to develop PCL, PCL/SF, PCL/SF/HA and PCL/SF/HA/MH hybrid biocomposite nanoparticles and characterization was analyzed by field emission scanning electron microscope (FESEM), contact angle and Fourier transform infrared spectroscopy (FT-IR). The obtained results proved that the particle diameter and water contact angle obtained around 0.54 ± 0.12 to 3.2 ± 0.18 µm and 43.93 ± 10.8° to 133.1 ± 12.4° respectively. The cell proliferation and cell-nanoparticle interactions analyzed using (3-(4,5-dimethyl thiazol-2-yl)-5-(3-carboxymethoxyphenyl)-2-(4-sulfophenyl)-2H-tetrazolium inner salt) MTS assay (Promega, Madison, WI, USA), FESEM for cell morphology and 5-Chloromethylfluorescein diacetate (CMFDA) dye for imaging live cells. Osteogenic differentiation was proved by expression of osteocalcin, alkaline phosphatase activity (ALP) and mineralization was confirmed by using alizarin red (ARS). The quantity of cells was considerably increased in PCL/SF/HA/MH nanoparticles when compare to all other biocomposite nanoparticles and the cell interaction was observed more on PCL/SF/HA/MH nanoparticles. The electrosprayed PCL/SF/HA/MH biocomposite nanoparticle significantly initiated increased cell proliferation, osteogenic differentiation and mineralization, which provide huge potential for bone tissue engineering. PMID

  16. Minocycline Loaded Hybrid Composites Nanoparticles for Mesenchymal Stem Cells Differentiation into Osteogenesis.

    Science.gov (United States)

    Tham, Allister Yingwei; Gandhimathi, Chinnasamy; Praveena, Jayaraman; Venugopal, Jayarama Reddy; Ramakrishna, Seeram; Kumar, Srinivasan Dinesh

    2016-01-01

    Bone transplants are used to treat fractures and increase new tissue development in bone tissue engineering. Grafting of massive implantations showing slow curing rate and results in cell death for poor vascularization. The potentials of biocomposite scaffolds to mimic extracellular matrix (ECM) and including new biomaterials could produce a better substitute for new bone tissue formation. A purpose of this study is to analyze polycaprolactone/silk fibroin/hyaluronic acid/minocycline hydrochloride (PCL/SF/HA/MH) nanoparticles initiate human mesenchymal stem cells (MSCs) proliferation and differentiation into osteogenesis. Electrospraying technique was used to develop PCL, PCL/SF, PCL/SF/HA and PCL/SF/HA/MH hybrid biocomposite nanoparticles and characterization was analyzed by field emission scanning electron microscope (FESEM), contact angle and Fourier transform infrared spectroscopy (FT-IR). The obtained results proved that the particle diameter and water contact angle obtained around 0.54 ± 0.12 to 3.2 ± 0.18 µm and 43.93 ± 10.8° to 133.1 ± 12.4° respectively. The cell proliferation and cell-nanoparticle interactions analyzed using (3-(4,5-dimethyl thiazol-2-yl)-5-(3-carboxymethoxyphenyl)-2-(4-sulfophenyl)-2H-tetrazolium inner salt) MTS assay (Promega, Madison, WI, USA), FESEM for cell morphology and 5-Chloromethylfluorescein diacetate (CMFDA) dye for imaging live cells. Osteogenic differentiation was proved by expression of osteocalcin, alkaline phosphatase activity (ALP) and mineralization was confirmed by using alizarin red (ARS). The quantity of cells was considerably increased in PCL/SF/HA/MH nanoparticles when compare to all other biocomposite nanoparticles and the cell interaction was observed more on PCL/SF/HA/MH nanoparticles. The electrosprayed PCL/SF/HA/MH biocomposite nanoparticle significantly initiated increased cell proliferation, osteogenic differentiation and mineralization, which provide huge potential for bone tissue engineering. PMID

  17. Minocycline Loaded Hybrid Composites Nanoparticles for Mesenchymal Stem Cells Differentiation into Osteogenesis

    Directory of Open Access Journals (Sweden)

    Allister Yingwei Tham

    2016-07-01

    Full Text Available Bone transplants are used to treat fractures and increase new tissue development in bone tissue engineering. Grafting of massive implantations showing slow curing rate and results in cell death for poor vascularization. The potentials of biocomposite scaffolds to mimic extracellular matrix (ECM and including new biomaterials could produce a better substitute for new bone tissue formation. A purpose of this study is to analyze polycaprolactone/silk fibroin/hyaluronic acid/minocycline hydrochloride (PCL/SF/HA/MH nanoparticles initiate human mesenchymal stem cells (MSCs proliferation and differentiation into osteogenesis. Electrospraying technique was used to develop PCL, PCL/SF, PCL/SF/HA and PCL/SF/HA/MH hybrid biocomposite nanoparticles and characterization was analyzed by field emission scanning electron microscope (FESEM, contact angle and Fourier transform infrared spectroscopy (FT-IR. The obtained results proved that the particle diameter and water contact angle obtained around 0.54 ± 0.12 to 3.2 ± 0.18 µm and 43.93 ± 10.8° to 133.1 ± 12.4° respectively. The cell proliferation and cell-nanoparticle interactions analyzed using (3-(4,5-dimethyl thiazol-2-yl-5-(3-carboxymethoxyphenyl-2-(4-sulfophenyl-2H-tetrazolium inner salt MTS assay (Promega, Madison, WI, USA, FESEM for cell morphology and 5-Chloromethylfluorescein diacetate (CMFDA dye for imaging live cells. Osteogenic differentiation was proved by expression of osteocalcin, alkaline phosphatase activity (ALP and mineralization was confirmed by using alizarin red (ARS. The quantity of cells was considerably increased in PCL/SF/HA/MH nanoparticles when compare to all other biocomposite nanoparticles and the cell interaction was observed more on PCL/SF/HA/MH nanoparticles. The electrosprayed PCL/SF/HA/MH biocomposite nanoparticle significantly initiated increased cell proliferation, osteogenic differentiation and mineralization, which provide huge potential for bone tissue engineering.

  18. Surface engineering of macrophages with nanoparticles to generate a cell–nanoparticle hybrid vehicle for hypoxia-targeted drug delivery

    Directory of Open Access Journals (Sweden)

    Christopher A Holden

    2009-12-01

    Full Text Available Christopher A Holden1, Quan Yuan1, W Andrew Yeudall2,3, Deborah A Lebman3,4, Hu Yang11Department of Biomedical Engineering, School of Engineering, 2Philips Institute of Oral and Craniofacial Molecular Biology, School of Dentistry, 3Massey Cancer Center, 4Department of Microbiology and Immunology, School of Medicine, Virginia Commonwealth University, Richmond, VA, USAAbstract: Tumors frequently contain hypoxic regions that result from a shortage of oxygen due to poorly organized tumor vasculature. Cancer cells in these areas are resistant to radiation- and chemotherapy, limiting the treatment efficacy. Macrophages have inherent hypoxia-targeting ability and hold great advantages for targeted delivery of anticancer therapeutics to cancer cells in hypoxic areas. However, most anticancer drugs cannot be directly loaded into macrophages because of their toxicity. In this work, we designed a novel drug delivery vehicle by hybridizing macrophages with nanoparticles through cell surface modification. Nanoparticles immobilized on the cell surface provide numerous new sites for anticancer drug loading, hence potentially minimizing the toxic effect of anticancer drugs on the viability and hypoxia-targeting ability of the macrophage vehicles. In particular, quantum dots and 5-(aminoacetamido fluoresceinlabeled polyamidoamine dendrimer G4.5, both of which were coated with amine-derivatized polyethylene glycol, were immobilized to the sodium periodate-treated surface of RAW264.7 macrophages through a transient Schiff base linkage. Further, a reducing agent, sodium cyanoborohydride, was applied to reduce Schiff bases to stable secondary amine linkages. The distribution of nanoparticles on the cell surface was confirmed by fluorescence imaging, and it was found to be dependent on the stability of the linkages coupling nanoparticles to the cell surface.Keywords: anticancer drug, cellular vehicle, confocal microscopy, dendrimer, drug delivery, hypoxia

  19. Mechanics of helical mesostructures from polymer-nanoparticle hybrids

    Science.gov (United States)

    Pham, Jonathan; Lawrence, Jimmy; Grason, Gregory; Emrick, Todd; Crosby, Alfred

    2015-03-01

    We describe the fabrication and mechanics of polymer and nanoparticle (NP)-based high-aspect ratio mesostructures, which we refer to as ribbons, with nm-scale cross-sections and up to cm-scale lengths. When placed into a fluid like water, interfacial tension associated with the ribbons' intrinsic geometric asymmetry balances the elastic cost of bending, turning ribbons into helices with tunable preferred curvature. This universal, elastocapillary-based mechanism enables the reversible formation of helices from a variety of polymer and NP compositions, as demonstrated with specific examples of poly(methyl methacrylate), CdSe quantum dots, and gold NPs with polystyrene-azide or undecene ligands. Using custom-designed characterization methods, we quantitatively show that helices are highly stretchable with force-displacement relationships described by a nonlinear spring of finite extensibility. At small strains, these helices generate nN forces, affording mesostructures with a stiffness similar to single polymer chains (ca. 10-6 N/m), and when fully stretched, they display properties similar to synthetic polymer nanofibers. These mesostructures offer a novel platform for engineering tunable materials with a broad range of mechanical properties and organic or inorganic functionality.

  20. Thermoelectric Behavior of Conducting Polymers Hybridized with Inorganic Nanoparticles

    Science.gov (United States)

    Son, Woohyun; Lee, Seung Hwan; Park, Hongkwan; Choi, Hyang Hee; Kim, Jung Hyun

    2016-06-01

    We introduce a simple and facile method for fabrication of a poly(3,4-ethylenedioxythiophene):poly(styrene sulfonate) (PEDOT:PSS)/germanium nanoparticle (Ge NP) composite film with enhanced thermoelectric conversion efficiency. The Ge NP were prepared by mechanical grinding and mixed with solution-phase PEDOT:PSS. The film processability of the composite was excellent and the overall process did not involve complicated synthetic procedures. The thermoelectric power factor of the composite film was optimized to 31.20 μW m-1 K-2 by controlling the composition. The composite film had an exceptionally low thermal conductivity of 0.417 W m-1 K-1 and the thermoelectric figure of merit ( ZT) was maximized at 0.0223 at room temperature. The mechanism for the improvement of the thermoelectric conversion efficiency was investigated by introducing energy models based on interfacial scattering of charge carriers and phonons. We expect that this robust method could lead to a facile route for design of organic-inorganic composite-based thermoelectric materials.

  1. Charge transfer and surface defect healing within ZnO nanoparticle decorated graphene hybrid materials

    Science.gov (United States)

    Pham, Chuyen V.; Repp, Sergej; Thomann, Ralf; Krueger, Michael; Weber, Stefan; Erdem, Emre

    2016-05-01

    To harness the unique properties of graphene and ZnO nanoparticles (NPs) for novel applications, the development of graphene-ZnO nanoparticle hybrid materials has attracted great attention and is the subject of ongoing research. For this contribution, graphene-oxide-ZnO (GO-ZnO) and thiol-functionalized reduced graphene oxide-ZnO (TrGO-ZnO) nanohybrid materials were prepared by novel self-assembly processes. Based on electron paramagnetic resonance (EPR) and photoluminescence (PL) investigations on bare ZnO NPs, GO-ZnO and TrGO-ZnO hybrid materials, we found that several physical phenomena were occurring when ZnO NPs were hybridized with GO and TrGO. The electrons trapped in Zn vacancy defects (VZn-) within the core of ZnO NPs vanished by transfer to GO and TrGO in the hybrid materials, thus leading to the disappearance of the core signals in the EPR spectra of ZnO NPs. The thiol groups of TrGO and sulfur can effectively ``heal'' the oxygen vacancy (VO+) related surface defects of ZnO NPs while oxygen-containing functionalities have low healing ability at a synthesis temperature of 100 °C. Photoexcited electron transfer from the conduction band of ZnO NPs to graphene leads to photoluminescence (PL) quenching of near band gap emission (NBE) of both GO-ZnO and TrGO-ZnO. Simultaneously, electron transfer from graphene to defect states of ZnO NPs is the origin of enhanced green defect emission from GO-ZnO. This observation is consistent with the energy level diagram model of hybrid materials.To harness the unique properties of graphene and ZnO nanoparticles (NPs) for novel applications, the development of graphene-ZnO nanoparticle hybrid materials has attracted great attention and is the subject of ongoing research. For this contribution, graphene-oxide-ZnO (GO-ZnO) and thiol-functionalized reduced graphene oxide-ZnO (TrGO-ZnO) nanohybrid materials were prepared by novel self-assembly processes. Based on electron paramagnetic resonance (EPR) and photoluminescence (PL

  2. In ovo delivery of Newcastle disease virus conjugated hybrid calcium phosphate nanoparticle and to study the cytokine profile induction

    Energy Technology Data Exchange (ETDEWEB)

    Viswanathan, Kaliyaperumal [Translational Research Platform for Veterinary Biologicals (TRPVB), Tamil Nadu Veterinary and Animal Sciences University, Chennai 600 051, Tamil Nadu (India); Rathish, P.; Gopinath, V.P.; Janice, R. [Department of Animal Biotechnology, Madras Veterinary College, Tamil Nadu Veterinary and Animal Sciences University, Chennai 600 007 (India); Dhinakar Raj, G., E-mail: dhinakarrajg@tanuvas.org.in [Department of Animal Biotechnology, Madras Veterinary College, Tamil Nadu Veterinary and Animal Sciences University, Chennai 600 007 (India); Translational Research Platform for Veterinary Biologicals (TRPVB), Tamil Nadu Veterinary and Animal Sciences University, Chennai 600 051, Tamil Nadu (India)

    2014-12-01

    In this report, the hybrid calcium phosphate (CaP) nanoparticles were synthesized and functionalized with Newcastle disease virus (NDV). These nanoparticles were synthesized by a combination of co-precipitation and polymerization process and functionalized with amino propyl triethoxy silane before coupling to NDV. The 5-dimethylthiazol-2-yl-2, 5-diphenyltetrazolium bromide (MTT) assay of chicken spleen cells incubated with these nanoparticles indicated that, these particles did not exert any significant cytotoxicity. The effects of hybrid CaP nanoparticles on cell cycle were assayed using a flow cytometer. The results demonstrated that the cell viability and proliferation capacity of spleen cells were not affected by hybrid CaP nanoparticles compared with their control cells. The hybrid CaP nanoparticles were characterized by scanning/transmission electron microscopy (SEM/TEM); Fourier transformed infrared spectroscopy (FTIR), X-ray diffraction patterns (XRD), Raman spectroscopy and energy-dispersive X-ray spectroscopy (EDX). These methods revealed that NDV was successfully conjugated on nanoparticles. The ability of the hybrid CaP nanoparticles to induce different cytokine mRNAs in the spleen cells of 18-day old embryonated chicken eggs (ECEs) was studied by quantitative real time polymerase chain reaction (qRT-PCR). NDV conjugated particles induced a high expression of Th1 cytokines such as interferon (IFN)-α, tumor necrosis factor (TNF)-α of and Th2 cytokines, interleukin (IL) 6 and IL-10. Uncoupled NDV induced only Th1 cytokines, IFN-α, INF-γ and TNF-α. The hybrid particles alone did not induce any cytokines. This confirmed that nanoparticle coupling could induce differential cytokine profiles and hence can be used as an alternate strategy to direct favorable immune responses in animals or chickens using appropriate vaccination carrier. - Highlights: • NDV conjugated hybrid CaP NP induced differential cytokine profiles in embryonated chicken eggs.

  3. Resonant photothermal laser processing of hybrid gold/titania nanoparticle films

    Science.gov (United States)

    Schade, Lina; Franzka, Steffen; Dzialkowski, Kevin; Hardt, Sebastian; Wiggers, Hartmut; Reichenberger, Sven; Wagener, Philipp; Hartmann, Nils

    2015-05-01

    Photothermal processing of thin anatase TiO2 and hybrid Au/anatase TiO2 nanoparticle films on glass supports is investigated using continuous-wave microfocused lasers at λ = 355 nm and λ = 532 nm. UV/Vis spectroscopy, Raman spectroscopy, optical microscopy, atomic force microscopy and scanning electron microscopy are used for characterization. Processing of TiO2 nanoparticle films is feasible at λ = 355 nm only. In contrast, the addition of Au nanoparticles enhances the overall absorbance of the material in the visible range and enables processing at both wavelengths, i.e. at λ = 355 nm and λ = 532 nm. Generally, laser heating induces a transition from anatase to rutile. The modification degree increases with increasing laser power and laser irradiation time. Resonant laser processing of hybrid Au/TiO2-mesoporous films provide promising perspectives in various applications, e.g. in photovoltaics, where embedded nanoparticulate Au could be exploited to enhance light trapping.

  4. Robust magnetic/polymer hybrid nanoparticles designed for crude oil entrapment and recovery in aqueous environments.

    Science.gov (United States)

    Pavía-Sanders, Adriana; Zhang, Shiyi; Flores, Jeniree A; Sanders, Jonathan E; Raymond, Jeffery E; Wooley, Karen L

    2013-09-24

    Well-defined, magnetic shell cross-linked knedel-like nanoparticles (MSCKs) with hydrodynamic diameters ca. 70 nm were constructed through the co-assembly of amphiphilic block copolymers of PAA20-b-PS280 and oleic acid-stabilized magnetic iron oxide nanoparticles using tetrahydrofuran, N,N-dimethylformamide, and water, ultimately transitioning to a fully aqueous system. These hybrid nanomaterials were designed for application as sequestering agents for hydrocarbons present in crude oil, based upon their combination of amphiphilic organic domains, for aqueous solution dispersibility and capture of hydrophobic guest molecules, with inorganic core particles for magnetic responsivity. The employment of these MSCKs in a contaminated aqueous environment resulted in the successful removal of the hydrophobic contaminants at a ratio of 10 mg of oil per 1 mg of MSCK. Once loaded, the crude oil-sorbed nanoparticles were easily isolated via the introduction of an external magnetic field. The recovery and reusability of these MSCKs were also investigated. These results suggest that deployment of hybrid nanocomposites, such as these, could aid in environmental remediation efforts, including at oil spill sites, in particular, following the bulk recovery phase. PMID:23987122

  5. Magnetic and rheological properties of monodisperse Fe{sub 3}O{sub 4} nanoparticle/organic hybrid

    Energy Technology Data Exchange (ETDEWEB)

    Hayashi, Koichiro; Sakamoto, Wataru [Division of Nanomaterials Science, EcoTopia Science Institute, Nagoya University, Furo-cho, Chikusa-ku, Nagoya 464-8603 (Japan); Yogo, Toshinobu [Division of Nanomaterials Science, EcoTopia Science Institute, Nagoya University, Furo-cho, Chikusa-ku, Nagoya 464-8603 (Japan)], E-mail: yogo@esi.nagoya-u.ac.jp

    2009-03-15

    Fe{sub 3}O{sub 4} nanoparticle/organic hybrids were synthesized via hydrolysis using iron (III) acetylacetonate at {approx}80 deg. C. The synthesis of Fe{sub 3}O{sub 4} was confirmed by X-ray diffraction, selected-area diffraction, and X-ray photoelectron spectroscopy. Fe{sub 3}O{sub 4} nanoparticles in the organic matrix had diameters ranging from 7 to 13 nm depending on the conditions of hydrolysis. The saturation magnetization of the hybrid increased with an increase in the particle size. When the hybrid contained Fe{sub 3}O{sub 4} particles with a size of less than 10 nm, it exhibited superparamagnetic behavior. The blocking temperature of the hybrid containing Fe{sub 3}O{sub 4} particles with a size of 7.3 nm was 200 K, and it increased to 310 K as the particle size increased to 9.1 nm. A hybrid containing Fe{sub 3}O{sub 4} particles of size greater than 10 nm was ferrimagnetic, and underwent Verwey transition at 130 K. Under a magnetic field, a suspension of the hybrid in silicone oil revealed the magnetorheological effect. The yield stress of the fluid was dependent on the saturation magnetization of Fe{sub 3}O{sub 4} nanoparticles in the hybrid, the strength of the magnetic field, and the amount of the hybrid.

  6. Hybrid biomaterials based on calcium carbonate and polyaniline nanoparticles for application in photothermal therapy.

    Science.gov (United States)

    Neira-Carrillo, Andrónico; Yslas, Edith; Marini, Yazmin Amar; Vásquez-Quitral, Patricio; Sánchez, Marianela; Riveros, Ana; Yáñez, Diego; Cavallo, Pablo; Kogan, Marcelo J; Acevedo, Diego

    2016-09-01

    Inorganic materials contain remarkable properties for drug delivery, such as a large surface area and nanoporous structure. Among these materials, CaCO3 microparticles (CMPs) exhibit a high encapsulation efficiency and solubility in acidic media. The extracellular pH of tumor neoplastic tissue is significantly lower than the extracellular pH of normal tissue facilitating the release of drug-encapsulating CMPs in this area. Conducting polyaniline (PANI) absorbs light energy and transforms it into localized heat to produce cell death. This work aimed to generate hybrid CMPs loaded with PANI for photothermal therapy (PTT). The hybrid nanomaterial was synthesized with CaCO3 and carboxymethyl cellulose in a simple, reproducible manner. The CMP-PANI-Cys particles were developed for the first time and represent a novel type of hybrid biomaterial. Resultant nanoparticles were characterized utilizing scanning electron microscopy, dynamic light scattering, zeta potential, UV-vis, FTIR and Raman spectroscopy. In vitro HeLa cells in dark and irradiated conditions showed that CMP-PANI-Cys and PANI-Cys are nontoxic at the assayed concentrations. Hybrid biomaterials displayed high efficiency for potential PTT compared with PANI-Cys. In summary, hierarchical hybrid biomaterials composed of CMPs and PANI-Cys combined with near infrared irradiation represents a useful alternative in PTT. PMID:27288818

  7. Enhanced Structural, Thermal, and Electrical Properties of Multiwalled Carbon Nanotubes Hybridized with Silver Nanoparticles

    Directory of Open Access Journals (Sweden)

    Yusliza Yusof

    2016-01-01

    Full Text Available The objective of this study is to evaluate the structural, thermal, and electrical properties of multiwalled carbon nanotubes (MWNT hybridized with silver nanoparticles (AgNP obtained via chemical reduction of aqueous silver salt assisted with sodium dodecyl sulphate (SDS as stabilizing agent. Transmission electron microscopy (TEM reveals microstructural analysis of the MWNT-Ag hybrids. The Fourier transform infrared (FTIR spectra prove the interactions between the AgNP and carboxyl groups of the MWNT. Raman spectra reveal that the D- to G-band intensity ratios ID/IG and ID′/IG increase upon the deposition of AgNP onto the surface of the MWNT. Thermogravimetric analysis (TGA shows that the MWNT-Ag hybrids decompose at a much faster rate and the weight loss decreased considerably due to the presence of AgNP. Nonlinearity of current-voltage (I-V curves indicates that electrical transport of pristine MWNT is enhanced when AgNP is induced as charge carriers in the MWNT-Ag hybrids. The threshold voltage Vth value for the MWNT doped with a maximum of 70 vol% of AgNP was substantially reduced by 65% relative to the pristine MWNT. The MWNT-Ag hybrids have a favourable electrical characteristic with a low threshold voltage that shows enhancement mode for field-effect transistor (FET applications.

  8. Hybrid biomaterials based on calcium carbonate and polyaniline nanoparticles for application in photothermal therapy.

    Science.gov (United States)

    Neira-Carrillo, Andrónico; Yslas, Edith; Marini, Yazmin Amar; Vásquez-Quitral, Patricio; Sánchez, Marianela; Riveros, Ana; Yáñez, Diego; Cavallo, Pablo; Kogan, Marcelo J; Acevedo, Diego

    2016-09-01

    Inorganic materials contain remarkable properties for drug delivery, such as a large surface area and nanoporous structure. Among these materials, CaCO3 microparticles (CMPs) exhibit a high encapsulation efficiency and solubility in acidic media. The extracellular pH of tumor neoplastic tissue is significantly lower than the extracellular pH of normal tissue facilitating the release of drug-encapsulating CMPs in this area. Conducting polyaniline (PANI) absorbs light energy and transforms it into localized heat to produce cell death. This work aimed to generate hybrid CMPs loaded with PANI for photothermal therapy (PTT). The hybrid nanomaterial was synthesized with CaCO3 and carboxymethyl cellulose in a simple, reproducible manner. The CMP-PANI-Cys particles were developed for the first time and represent a novel type of hybrid biomaterial. Resultant nanoparticles were characterized utilizing scanning electron microscopy, dynamic light scattering, zeta potential, UV-vis, FTIR and Raman spectroscopy. In vitro HeLa cells in dark and irradiated conditions showed that CMP-PANI-Cys and PANI-Cys are nontoxic at the assayed concentrations. Hybrid biomaterials displayed high efficiency for potential PTT compared with PANI-Cys. In summary, hierarchical hybrid biomaterials composed of CMPs and PANI-Cys combined with near infrared irradiation represents a useful alternative in PTT.

  9. Hybrid plasmonic magnetic nanoparticles as molecular specific agents for MRI/optical imaging and photothermal therapy of cancer cells

    Energy Technology Data Exchange (ETDEWEB)

    Larson, Timothy A [Department of Biomedical Engineering, University of Texas at Austin, Austin, TX 78712 (United States); Bankson, James [Department of Imaging Physics, University of Texas MD Anderson Cancer Center, Houston, TX 77030 (United States); Aaron, Jesse [Department of Biomedical Engineering, University of Texas at Austin, Austin, TX 78712 (United States); Sokolov, Konstantin [Department of Biomedical Engineering, University of Texas at Austin, Austin, TX 78712 (United States)

    2007-08-15

    Nanoparticles which consist of a plasmonic layer and an iron oxide moiety could provide a promising platform for development of multimodal imaging and therapy approaches in future medicine. However, the feasibility of this platform has yet to be fully explored. In this study we demonstrated the use of gold-coated iron oxide hybrid nanoparticles for combined molecular specific MRI/optical imaging and photothermal therapy of cancer cells. The gold layer exhibits a surface plasmon resonance that provides optical contrast due to light scattering in the visible region and also presents a convenient surface for conjugating targeting moieties, while the iron oxide cores give strong T{sub 2} (spin-spin relaxation time) contrast. The strong optical absorption of the plasmonic gold layer also makes these nanoparticles a promising agent for photothermal therapy. We synthesized hybrid nanoparticles which specifically target epidermal growth factor receptor (EGFR), a common biomarker for many epithelial cancers. We demonstrated molecular specific MRI and optical imaging in MDA-MB-468 breast cancer cells. Furthermore, we showed that receptor-mediated aggregation of anti-EGFR hybrid nanoparticles allows selective destruction of highly proliferative cancer cells using a nanosecond pulsed laser at 700 nm wavelength, a significant shift from the peak absorbance of isolated hybrid nanoparticles at 532 nm.

  10. Hybrid plasmonic magnetic nanoparticles as molecular specific agents for MRI/optical imaging and photothermal therapy of cancer cells

    International Nuclear Information System (INIS)

    Nanoparticles which consist of a plasmonic layer and an iron oxide moiety could provide a promising platform for development of multimodal imaging and therapy approaches in future medicine. However, the feasibility of this platform has yet to be fully explored. In this study we demonstrated the use of gold-coated iron oxide hybrid nanoparticles for combined molecular specific MRI/optical imaging and photothermal therapy of cancer cells. The gold layer exhibits a surface plasmon resonance that provides optical contrast due to light scattering in the visible region and also presents a convenient surface for conjugating targeting moieties, while the iron oxide cores give strong T2 (spin-spin relaxation time) contrast. The strong optical absorption of the plasmonic gold layer also makes these nanoparticles a promising agent for photothermal therapy. We synthesized hybrid nanoparticles which specifically target epidermal growth factor receptor (EGFR), a common biomarker for many epithelial cancers. We demonstrated molecular specific MRI and optical imaging in MDA-MB-468 breast cancer cells. Furthermore, we showed that receptor-mediated aggregation of anti-EGFR hybrid nanoparticles allows selective destruction of highly proliferative cancer cells using a nanosecond pulsed laser at 700 nm wavelength, a significant shift from the peak absorbance of isolated hybrid nanoparticles at 532 nm

  11. Cadmium Sulfide Nanoparticles Synthesized by Microwave Heating for Hybrid Solar Cell Applications

    Directory of Open Access Journals (Sweden)

    Claudia Martínez-Alonso

    2014-01-01

    Full Text Available Cadmium sulfide nanoparticles (CdS-n are excellent electron acceptor for hybrid solar cell applications. However, the particle size and properties of the CdS-n products depend largely on the synthesis methodologies. In this work, CdS-n were synthetized by microwave heating using thioacetamide (TA or thiourea (TU as sulfur sources. The obtained CdS-n(TA showed a random distribution of hexagonal particles and contained TA residues. The latter could originate the charge carrier recombination process and cause a low photovoltage (Voc, 0.3 V in the hybrid solar cells formed by the inorganic particles and poly(3-hexylthiophene (P3HT. Under similar synthesis conditions, in contrast, CdS-n synthesized with TU consisted of spherical particles with similar size and contained carbonyl groups at their surface. CdS-n(TU could be well dispersed in the nonpolar P3HT solution, leading to a Voc of about 0.6–0.8 V in the resulting CdS-n(TU : P3HT solar cells. The results of this work suggest that the reactant sources in microwave methods can affect the physicochemical properties of the obtained inorganic semiconductor nanoparticles, which finally influenced the photovoltaic performance of related hybrid solar cells.

  12. Facile preparation of TiO2–polyvinyl alcohol hybrid nanoparticles with improved visible light photocatalytic activity

    International Nuclear Information System (INIS)

    Graphical abstract: - Highlights: • Hybrid TiO2/PVA core/shell nanoparticles were prepared through a two step procedure. • TiO2–PVA samples were prepared based on different TiO2–PVA weight ratios. • All samples were characterized using XRD, TEM, FT-IR and BET analysis. • The photocatalytic performance was evaluated. - Abstract: Hybrid inorganic/organic core/shell nanoparticles were prepared through a two step synthesis procedure. In the first step, pure anatase TiO2 nanoparticles were synthesized though a rapid microwave assisted non-aqueous route. Then, the obtained titania nanoparticles were coated with polyvinyl alcohol (PVA) using a simple solution method followed by relatively low temperature treatment. The PVA-coated titania nanoparticles samples were prepared at different TiO2–PVA weight ratio and they were characterized using X-Ray diffraction, transmission electron microscopy, infrared spectroscopy and Brunauer–Emmett–Teller (BET) analysis. Photocatalytic performance was also evaluated for all samples and the results indicated that TiO2:PVA weight ratio was a key factor to obtain an improvement of the photocatalytic activity with respect to bare TiO2 nanoparticles, since PVA concentration influenced the surface area and the aggregation of nanoparticles and the thickness of the coating layer. This inexpensive system provides a simple, quick and effective approach which allows to obtain core/shell hybrid nanostructures

  13. Facile preparation of TiO{sub 2}–polyvinyl alcohol hybrid nanoparticles with improved visible light photocatalytic activity

    Energy Technology Data Exchange (ETDEWEB)

    Filippo, Emanuela [Department of Innovation Engineering, University of Salento, Monteroni Street, 73100, Lecce (Italy); Carlucci, Claudia; Capodilupo, Agostina Lina [National Nanotechnology Laboratory (NNL), Nanoscience Institure – CNR, Arnesano Street, 73100 Lecce (Italy); Perulli, Patrizia [Department of Innovation Engineering, University of Salento, Monteroni Street, 73100, Lecce (Italy); Conciauro, Francesca [National Nanotechnology Laboratory (NNL), Nanoscience Institure – CNR, Arnesano Street, 73100 Lecce (Italy); Corrente, Giuseppina Anna [University of Calabria, Pietro Bucci Street, 87036 Arcavacata di Rende, Cosenza (Italy); Gigli, Giuseppe [National Nanotechnology Laboratory (NNL), Nanoscience Institure – CNR, Arnesano Street, 73100 Lecce (Italy); Center for Biomolecular Nanotechnologies (CBN) of Italian Institute of Technology (IIT), Barsanti Street 1, 73010 Arnesano (Italy); Department of Physics, University of Salento, Monteroni Street, 73100, Lecce (Italy); Ciccarella, Giuseppe, E-mail: giuseppe.ciccarella@unisalento.it [Department of Innovation Engineering, University of Salento, Monteroni Street, 73100, Lecce (Italy); National Nanotechnology Laboratory (NNL), Nanoscience Institure – CNR, Arnesano Street, 73100 Lecce (Italy)

    2015-03-15

    Graphical abstract: - Highlights: • Hybrid TiO{sub 2}/PVA core/shell nanoparticles were prepared through a two step procedure. • TiO{sub 2}–PVA samples were prepared based on different TiO{sub 2}–PVA weight ratios. • All samples were characterized using XRD, TEM, FT-IR and BET analysis. • The photocatalytic performance was evaluated. - Abstract: Hybrid inorganic/organic core/shell nanoparticles were prepared through a two step synthesis procedure. In the first step, pure anatase TiO{sub 2} nanoparticles were synthesized though a rapid microwave assisted non-aqueous route. Then, the obtained titania nanoparticles were coated with polyvinyl alcohol (PVA) using a simple solution method followed by relatively low temperature treatment. The PVA-coated titania nanoparticles samples were prepared at different TiO{sub 2}–PVA weight ratio and they were characterized using X-Ray diffraction, transmission electron microscopy, infrared spectroscopy and Brunauer–Emmett–Teller (BET) analysis. Photocatalytic performance was also evaluated for all samples and the results indicated that TiO{sub 2}:PVA weight ratio was a key factor to obtain an improvement of the photocatalytic activity with respect to bare TiO{sub 2} nanoparticles, since PVA concentration influenced the surface area and the aggregation of nanoparticles and the thickness of the coating layer. This inexpensive system provides a simple, quick and effective approach which allows to obtain core/shell hybrid nanostructures.

  14. Hybrid mode-locked fiber ring laser using graphene and charcoal nanoparticles as saturable absorbers

    Science.gov (United States)

    Hu, Hongyu; Zhang, Xiang; Li, Wenbo; Dutta, Niloy K.

    2016-05-01

    A fiber ring laser which implements hybrid mode locking technique has been proposed and experimentally demonstrated to generate pulse train at 20 GHz repetition rate with ultrashort pulse width. Graphene and charcoal nano-particles acting as passive mode lockers are inserted into a rational harmonic mode-locked fiber laser to improve the performance. With graphene saturable absorbers, the pulse duration is shortened from 5.3 ps to 2.8 ps, and with charcoal nano-particles, it is shortened to 3.2 ps. The RF spectra show that supermode noise can be removed in the presence of the saturable absorbers. Numerical simulation of the pulse transmission has also been carried out, which shows good agreement with the experimental results.

  15. Controlled reduction of photobleaching in DNA origami-gold nanoparticle hybrids.

    Science.gov (United States)

    Pellegrotti, Jesica V; Acuna, Guillermo P; Puchkova, Anastasiya; Holzmeister, Phil; Gietl, Andreas; Lalkens, Birka; Stefani, Fernando D; Tinnefeld, Philip

    2014-05-14

    The amount of information obtainable from a fluorescence-based measurement is limited by photobleaching: Irreversible photochemical reactions either render the molecules nonfluorescent or shift their absorption and/or emission spectra outside the working range. Photobleaching is evidenced as a decrease of fluorescence intensity with time, or in the case of single molecule measurements, as an abrupt, single-step interruption of the fluorescence emission that determines the end of the experiment. Reducing photobleaching is central for improving fluorescence (functional) imaging, single molecule tracking, and fluorescence-based biosensors and assays. In this single molecule study, we use DNA self-assembly to produce hybrid nanostructures containing individual fluorophores and gold nanoparticles at a controlled separation distance of 8.5 nm. By changing the nanoparticles' size we are able to systematically increase the mean number of photons emitted by the fluorophores before photobleaching.

  16. NOVEL HYBRID GENE VECTOR STABILIZED BY CROSS-LINKING WITH GOLD NANOPARTICLES

    Institute of Scientific and Technical Information of China (English)

    You-xiang Wang; Ying Zhu; Jia-cong Shen

    2008-01-01

    Enhanced stability of polyplexes in physiological condition was an important prerequisite for successful systemic gene delivery. Herein novel method was reported to develop stable gene vector by nanotechnology. Thiolated polyplexes were constructed and then cross-linked with gold nanoparticles (AuNPs) by gold-thiol interactions. TEM pictures showed that AuNPs were attached to the shell of spherical polyplexes. The hybrid gene vector was stable enough in physiological condition and maintained efficient transfection, which showed great potential in gene delivery research and application.

  17. Synthetic Polymer Hybridization with DNA and RNA Directs Nanoparticle Loading, Silencing Delivery, and Aptamer Function.

    Science.gov (United States)

    Zhou, Zhun; Xia, Xin; Bong, Dennis

    2015-07-22

    We report herein discrete triplex hybridization of DNA and RNA with polyacrylates. Length-monodisperse triazine-derivatized polymers were prepared on gram-scale by reversible addition-fragmentation chain-transfer polymerization. Despite stereoregio backbone heterogeneity, the triazine polymers bind T/U-rich DNA or RNA with nanomolar affinity upon mixing in a 1:1 ratio, as judged by thermal melts, circular dichroism, gel-shift assays, and fluorescence quenching. We call these polyacrylates "bifacial polymer nucleic acids" (bPoNAs). Nucleic acid hybridization with bPoNA enables DNA loading onto polymer nanoparticles, siRNA silencing delivery, and can further serve as an allosteric trigger of RNA aptamer function. Thus, bPoNAs can serve as tools for both non-covalent bioconjugation and structure-function nucleation. It is anticipated that bPoNAs will have utility in both bio- and nanotechnology. PMID:26138550

  18. High Performance Ultraviolet Photodetector Fabricated with ZnO Nanoparticles-graphene Hybrid Structures

    Institute of Scientific and Technical Information of China (English)

    Jin-yang Liu; Xin-xin Yu; Guang-hui Zhang; Yu-kun Wu; Kun Zhang; Nan Pan; Xiao-ping Wang

    2013-01-01

    Ultraviolet (UV) photodetector constructed by ZnO material has attracted intense research and commercial interest.However,its photoresistivity and photoresonse are still unsatisfied.Herein,we report a novel method to assemble ZnO nanoparticles (NPs) onto the reduced graphite oxide (RGO) sheet by simple hydrothermal process without any surfactant.It is found that the high-quality crystallized ZnO NPs with the average diameter of 5 nm are well dispersed on the RGO surface,and the density of ZnO NPs can be readily controlled by the concentration of the precursor.The photodetector fabricated with this ZnO NPs-RGO hybrid structure demonstrates an excellent photoresponse for the UV irradiation.The results make this hybrid especially suitable as a novel material for the design and fabrication of high performance UV photodector.

  19. Self-assembled dipeptide-gold nanoparticle hybrid spheres for highly sensitive amperometric hydrogen peroxide biosensors.

    Science.gov (United States)

    Gong, Yufei; Chen, Xu; Lu, Yanluo; Yang, Wensheng

    2015-04-15

    Novel self-assembled dipeptide-gold nanoparticle (DP-AuNP) hybrid microspheres with a hollow structure have been prepared in aqueous solution by a simple one-step method. Diphenylalanine (FF) dipeptide was used as a precursor to form simultaneously peptide spheres and a reducing agent to reduce gold ions to gold nanoparticles in water at 60°C. Scanning electron microscopy (SEM) and transmission electron microscopy (TEM) revealed that formed AuNPs were localized both inside and on the surface of the dipeptide spheres. Horseradish peroxidase (HRP) as a model enzyme was further immobilized on the dipeptide-AuNP hybrid spheres to construct a mediate H2O2 amperometric biosensor. UV-vis spectroscopy showed that the immobilized HRP retained its original structure. Cyclic voltammetry characterization demonstrated that the HRP/dipeptide-AuNP hybrid spheres modified glassy carbon electrode showed high electrocatalytic activity to H2O2. The proposed biosensor exhibited a wide linear response in the range from 5.0×10(-7) to 9.7×10(-4)M with a high sensitivity of 28.3µAmM(-1). A low detection limit of 1.0×10(-7)M was estimated at S/N=3. In addition, the biosensor possessed satisfactory reproducibility and long-term stability. These results indicated that the dipeptide-AuNP hybrid sphere is a promising matrix for application in the fabrication of electrochemical biosensors due to its excellent biocompatibility and good charge-transfer ability. PMID:25483915

  20. Hybrid light emitting diodes based on solution processed polymers, colloidal quantum dots, and colloidal metal nanoparticles

    Science.gov (United States)

    Ma, Xin

    This dissertation focuses on solution-processed light-emitting devices based on polymer, polymer/PbS quantum dot, and polymer/silver nanoparticle hybrid materials. Solution based materials and organic/inorganic hybrid light emitting diodes attracted significant interest recently due to many of their advantages over conventional light emitting diodes (LEDs) including low fabrication cost, flexible, high substrate compatibility, as well as tunable emission wavelength of the quantum dot materials. However, the application of these novel solution processed materials based devices is still limited due to their low performances. Material properties and fabrication parameters need to be carefully examined and understood for further device improvement. This thesis first investigates the impact of solvent property and evaporation rate on the polymer molecular chain morphology and packaging in device structures. Solvent is a key component to make the active material solution for spin coating fabrication process. Their impacts are observed and examined on both polymer blend system and mono-polymer device. Secondly, PbS colloidal quantum dot are introduced to form hybrid device with polymer and to migrate the device emission into near-IR range. As we show, the dithiol molecules used to cross-link quantum dots determine the optical and electrical property of the resulting thin films. By choosing a proper ligand for quantum dot ligand exchange, a high performance polymer/quantum dot hybrid LED is fabricated. In the end, the interaction of polymer exciton with surface plasmon mode in colloidal silver nanoparticles and the use of this effect to enhance solution processed LEDs' performances are investigated.

  1. How to control optical activity in organic-silver hybrid nanoparticles

    Science.gov (United States)

    Hidalgo, Francisco; Noguez, Cecilia

    2016-07-01

    The mechanisms that originate and control optical activity in organic-metal hybrid nanoparticles (NPs) are identified using a time-perturbed density functional theory. Electronic circular dichroism (CD) is studied in terms of the intrinsic chirality of the ligands, the number of ligands and the induced chirality by the arrangement of the ligands on the NP. Left-handed cysteine and achiral methylthio ligands adsorbed on an icosahedral silver NP are investigated. The analysis of CD allows the identification of the spectral regions when the induced chirality by the ligand array dominates over the intrinsic chirality of the ligands, determining conditions for CD control and enlargement. These results would be significant in the discussion of experimental CD spectra of organic-metal hybrid NPs, which might allow the development of new strategies to improve the sensitivity of chiroptical spectroscopies for the identification of bio and organic molecules.The mechanisms that originate and control optical activity in organic-metal hybrid nanoparticles (NPs) are identified using a time-perturbed density functional theory. Electronic circular dichroism (CD) is studied in terms of the intrinsic chirality of the ligands, the number of ligands and the induced chirality by the arrangement of the ligands on the NP. Left-handed cysteine and achiral methylthio ligands adsorbed on an icosahedral silver NP are investigated. The analysis of CD allows the identification of the spectral regions when the induced chirality by the ligand array dominates over the intrinsic chirality of the ligands, determining conditions for CD control and enlargement. These results would be significant in the discussion of experimental CD spectra of organic-metal hybrid NPs, which might allow the development of new strategies to improve the sensitivity of chiroptical spectroscopies for the identification of bio and organic molecules. Electronic supplementary information (ESI) available. See DOI: 10.1039/C6

  2. Lipid-polymer hybrid nanoparticles with rhamnolipid-triggered release capabilities as anti-biofilm drug delivery vehicles

    Institute of Scientific and Technical Information of China (English)

    Wean Sin Cheow; Kunn Hadinoto

    2012-01-01

    In lung biofilm infection therapies,the use of lipid-polymer hybrid nanoparticles to encapsulate drugs has emerged as a promising alternative to using liposomes because they have superior physicochemical stability and still possess the biofilm affinity and sputum-penetrating ability of liposomes.To be deemed equally efficacious as liposomes against bacterial biofilms,however,the capability of hybrid nanoparticles to target-release encapsulated drugs at biofilm colonies must be demonstrated.This communication details our investigations into the trigger-release characteristics of hybrid nanoparticles in response to encountering rhamnolipids,which are ubiquitously present in biofilm colonies of Pseudomonas aeruginosa,a major respiratory pathogen.Poly(lactic-co-glycolic acid) and phosphatidylcholine were used as the polymer nanoparticle core and lipid coat,respectively.These investigations were performed using compounds from various biopharmaceutical classification systems (BCS) that differ in their lipid-membrane permeabilities.The release of BCS Class Ⅲ compounds.which have poor lipid-membrane permeabilities,was successfully triggered by rhamnolipids at a concentration approximately equal to their clinically observed value,and this release was attributed to the disruption of lipid coats by rhamnolipid micelles.Not unexpectedly,BCS Class Ⅰ compounds,which have high lipid-membrane permeabilities,were released freely whether or not rhamnolipids were present.The rate of the triggered release can be controlled by incorporating an additional lipid layer on the hybrid nanoparticles via the electrostatically driven adsorption of lipid vesicles.

  3. The characteristics of novel bimodal Ag-TiO2 nanoparticles generated by hybrid laser-ultrasonic technique

    Science.gov (United States)

    Hamad, Abubaker; Li, Lin; Liu, Zhu; Zhong, Xiang Li; Burke, Grace; Wang, Tao

    2016-04-01

    Silver-titania (Ag-TiO2) nanoparticles with smaller Ag nanoparticles attached to larger TiO2 nanoparticles were generated by hybrid ultrasonic vibration and picosecond laser ablation of Ag and Ti bulk targets in deionised water, for the first time. The laser has a wavelength of 1064 nm and a pulse duration of 10 ps. It was observed that without the ultrasonic vibration, Ag and TiO2 nanoparticles did not combine, thus the role of ultrasonic vibration is essential. In addition, colloidal TiO2 and Ag nanoparticles were generated separately for comparison under the same laser beam characteristics and process conditions. The absorption spectra of colloidal Ag-TiO2 cluster nanoparticles were examined by UV-Vis spectroscopy, and size distribution was characterised using transmission electron microscopy. The morphology and composition of Ag-TiO2 nanoparticles were examined using scanning transmission electron microscopy in high-angle annular dark field, and energy-dispersive X-ray spectroscopy. The crystalline structures were investigated by X-ray diffraction. The size of larger TiO2 particles was in the range 30-150 nm, and the smaller-sized Ag nanoparticles attached to the TiO2 was mainly in the range of 10-15 nm. The yield is more than 50 % with the remaining nanoparticles in the form of uncombined Ag and TiO2. The nanoparticles generated had strong antibacterial effects as tested against E. coli. A discussion is given on the role of ultrasonic vibration in the formation of Ag-TiO2 hybrid nanoparticles by picosecond laser ablation.

  4. Hybrid magnetite nanoparticles/ Rosmarinus officinalis essential oil nanobiosystem with antibiofilm activity

    Science.gov (United States)

    Chifiriuc, Carmen; Grumezescu, Valentina; Grumezescu, Alexandru Mihai; Saviuc, Crina; Lazăr, Veronica; Andronescu, Ecaterina

    2012-04-01

    Biofilms formed by fungal organisms are associated with drastically enhanced resistance against most antimicrobial agents, contributing to the persistence of the fungi despite antifungal therapy. The purpose of this study is to combine the unique properties of nanoparticles with the antimicrobial activity of the Rosmarinus officinalis essential oil in order to obtain a nanobiosystem that could be pelliculised on the surface of catheter pieces, in order to obtain an improved resistance to microbial colonization and biofilm development by Candida albicans and C. tropicalis clinical strains. The R. officinalis essential oils were extracted in a Neo-Clevenger type apparatus, and its chemical composition was settled by GC-MS analysis. Functionalized magnetite nanoparticles of up to 20 nm size had been synthesized by precipitation method adapted for microwave conditions, with oleic acid as surfactant. The catheter pieces were coated with suspended core/shell nanoparticles (Fe3O4/oleic acid:CHCl3), by applying a magnetic field on nanofluid, while the CHCl3 diluted essential oil was applied by adsorption in a secondary covering treatment. The fungal adherence ability was investigated in six multiwell plates, in which there have been placed catheters pieces with and without hybrid nanoparticles/essential oil nanobiosystem pellicle, by using culture-based methods and confocal laser scanning microscopy (CLSM). The R. officinalis essential oil coated nanoparticles strongly inhibited the adherence ability and biofilm development of the C. albicans and C. tropicalis tested strains to the catheter surface, as shown by viable cell counts and CLSM examination. Due to the important implications of C andida spp. in human pathogenesis, especially in prosthetic devices related infections and the emergence of antifungal tolerance/resistance, using the new core/shell/coated shell based on essential oil of R. officinalis to inhibit the fungal adherence could be of a great interest for the

  5. Intracellular siRNA delivery dynamics of integrin-targeted, PEGylated chitosan-poly(ethylene imine) hybrid nanoparticles

    DEFF Research Database (Denmark)

    Ragelle, Héloïse; Colombo, Stefano; Pourcelle, Vincent;

    2015-01-01

    chitosan-poly(ethylene imine) hybrid nanoparticles. The amount of intracellular siRNA delivered by αvβ3-targeted versus non-targeted nanoparticles was quantified in the human non-small cell lung carcinoma cell line H1299 expressing enhanced green fluorescent protein (EGFP) using a stem-loop reverse......-fold increase in the number of siRNA copies/cell, subsequently resulting in as much as 90% silencing of EGFP at well-tolerated carrier concentrations. In contrast, non-targeted nanoparticles mediated low levels of gene silencing, despite relatively high intracellular siRNA concentrations, indicating...

  6. Enzymatic functionalization of cork surface with antimicrobial hybrid biopolymer/silver nanoparticles.

    Science.gov (United States)

    Francesko, Antonio; Blandón, Lucas; Vázquez, Mario; Petkova, Petya; Morató, Jordi; Pfeifer, Annett; Heinze, Thomas; Mendoza, Ernest; Tzanov, Tzanko

    2015-05-13

    Laccase-assisted assembling of hybrid biopolymer-silver nanoparticles and cork matrices into an antimicrobial material with potential for water remediation is herein described. Amino-functional biopolymers were first used as doping agents to stabilize concentrated colloidal dispersions of silver nanoparticles (AgNP), additionally providing the particles with functionalities for covalent immobilization onto cork to impart a durable antibacterial effect. The solvent-free AgNP synthesis by chemical reduction was carried out in the presence of chitosan (CS) or 6-deoxy-6-(ω-aminoethyl) aminocellulose (AC), leading to simultaneous AgNP biofunctionalization. This approach resulted in concentrated hybrid NP dispersion stable to aggregation and with hydrodynamic radius of particles of about 250 nm. Moreover, laccase enabled coupling between the phenolic groups in cork and amino moieties in the biopolymer-doped AgNP for permanent modification of the material. The antibacterial efficiency of the functionalized cork matrices, aimed as adsorbents for wastewater treatment, was evaluated against Escherichia coli and Staphylococcus aureus during 5 days in conditions mimicking those in constructed wetlands. Both intrinsically antimicrobial CS and AC contributed to the bactericidal effect of the enzymatically grafted on cork AgNP. In contrast, unmodified AgNP were easily washed off from the material, confirming that the biopolymers potentiated a durable antibacterial functionalization of the cork matrices.

  7. Dechlorination of Environmental Contaminants Using a Hybrid Nanocatalyst: Palladium Nanoparticles Supported on Hierarchical Carbon Nanostructures

    Directory of Open Access Journals (Sweden)

    Hema Vijwani

    2012-01-01

    Full Text Available This paper demonstrates the effectiveness of a new type of hybrid nanocatalyst material that combines the high surface area of nanoparticles and nanotubes with the structural robustness and ease of handling larger supports. The hybrid material is made by fabricating palladium nanoparticles on two types of carbon supports: as-received microcellular foam (Foam and foam with carbon nanotubes anchored on the pore walls (CNT/Foam. Catalytic reductive dechlorination of carbon tetrachloride with these materials has been investigated using gas chromatography. It is seen that while both palladium-functionalized carbon supports are highly effective in the degradation of carbon tetrachloride, the rate of degradation is significantly increased with palladium on CNT/Foam. However, there is scope to increase this rate further if the wettability of these structures can be enhanced in the future. Microstructural and spectroscopic analyses of the fresh and used catalysts have been compared which indicates that there is no change in density or surface chemical states of the catalyst after prolonged use in dechlorination test. This implies that these materials can be used repeatedly and hence provide a simple, powerful, and cost-effective approach for dechlorination of water.

  8. Effect of SO 2 on CO 2 Capture Using Liquid-like Nanoparticle Organic Hybrid Materials

    KAUST Repository

    Lin, Kun-Yi Andrew

    2013-08-15

    Liquid-like nanoparticle organic hybrid materials (NOHMs), consisting of silica nanoparticles with a grafted polymeric canopy, were synthesized. Previous work on NOHMs has revealed that CO2 capture behaviors in these hybrid materials can be tuned by modifying the structure of the polymeric canopy. Because SO2, which is another acidic gas found in flue gas, would also interact with NOHMs, this study was designed to investigate its effect on CO2 capture in NOHMs. In particular, CO2 capture capacities as well as swelling and CO2 packing behaviors of NOHMs were analyzed using thermogravimetric analyses and Raman and attenuated total reflectance (ATR) Fourier transform infrared (FTIR) spectroscopies before and after exposure of NOHMs to SO2. It was found that the SO2 absorption in NOHMs was only prominent at high SO2 levels (i.e., 3010 ppm; Ptot = 0.4 MPa) far exceeding the typical SO2 concentration in flue gas. As expected, the competitive absorption between SO2 and CO2 for the same absorption sites (i.e., ether and amine groups) resulted in a decreased CO2 capture capacity of NOHMs. The swelling of NOHMs was not notably affected by the presence of SO 2 within the given concentration range (Ptot = 0-0.68 MPa). On the other hand, SO2, owing to its Lewis acidic nature, interacted with the ether groups of the polymeric canopy and, thus, changed the CO2 packing behaviors in NOHMs. © 2013 American Chemical Society.

  9. Novel Alginate-Gelatin Hybrid Nanoparticle for Drug Delivery and Tissue Engineering Applications

    Directory of Open Access Journals (Sweden)

    Eun Mi Lee

    2014-01-01

    Full Text Available Novel alginate-gelatin hybrid nanoparticles were fabricated using single oil in water (O/W emulsification techniques. Physicochemical property of the particle was characterized using scanning electron microscopy and Fourier’s transmission infrared spectroscopy. Particle size was determined using zeta potential metastasize analyzer and was found to be in range of 400–600 nm. AGNPs were used for culturing human keratinocytes for two weeks to check biocompatibility of synthesized AGNPs. 3-(4,5-Dimethylthiazol-2-yl-2,5-diphenyltetrazolium bromide (MTT assay showed increased metabolic activity of cells cultured on AGNPs in comparison to two-dimensional (2D system (control. Cellular attachment on nanoparticle was further confirmed using SEM and 4′,6-diamidino-2-phenylindole staining. The drug release profile shows possible electrostatic bond between alginate and gelatin resulting in controlled release of drug from AGNPs. For the first time alginate-gelatin hybrid nanosystem has been fabricated and all results showed it can be used as potential system for delivery of drug and therapeutical agents to cells and can also be used for regenerative medicine applications.

  10. Synthesis and characterization of multifunctional hybrid-polymeric nanoparticles for drug delivery and multimodal imaging of cancer

    Directory of Open Access Journals (Sweden)

    Tng DJH

    2015-09-01

    Full Text Available Danny Jian Hang Tng,1,* Peiyi Song,1,* Guimiao Lin,2,3,* Alana Mauluidy Soehartono,1 Guang Yang,1 Chengbin Yang,1 Feng Yin,1 Cher Heng Tan,4 Ken-Tye Yong1 1School of Electrical and Electronic Engineering, Nanyang Technological University, Singapore; 2The Engineering Lab of Synthetic Biology, 3Research Institute of Uropoiesis and Reproduction, School of Medicine, Shenzhen University, Shenzhen, People’s Republic of China; 4Department of Diagnostic Radiology, Tan Tock Seng Hospital, Singapore *These authors contributed equally to this work Abstract: In this study, multifunctional hybrid-polymeric nanoparticles were prepared for the treatment of cultured multicellular tumor spheroids (MCTS of the PANC-1 and MIA PaCa-2 pancreatic carcinoma cell lines. To synthesize the hybrid-polymeric nanoparticles, the poly lactic-co-glycolic acid core of the particles was loaded with Rhodamine 6G dye and the chemotherapeutic agent, Paclitaxel, was incorporated into the outer phospholipid layer. The surface of the nanoparticles was coated with gadolinium chelates for magnetic resonance imaging applications. This engineered nanoparticle formulation was found to be suitable for use in guided imaging therapy. Specifically, we investigated the size-dependent therapeutic response and the uptake of nanoparticles that were 65 nm, 85 nm, and 110 nm in size in the MCTS of the two pancreatic cancer cell lines used. After 24 hours of treatment, the MCTS of both PANC-1 and MIA PaCa-2 cell lines showed an average increase in the uptake of 18.4% for both 65 nm and 85 nm nanoparticles and 24.8% for 110 nm nanoparticles. Furthermore, the studies on therapeutic effects showed that particle size had a slight influence on the overall effectiveness of the formulation. In the MCTS of the MIA PaCa-2 cell line, 65 nm nanoparticles were found to produce the greatest therapeutic effect, whereas 12.8% of cells were apoptotic of which 11.4% of cells were apoptotic for 85

  11. Dependence of SERS enhancement on the chemical composition and structure of Ag/Au hybrid nanoparticles.

    Science.gov (United States)

    Chaffin, Elise; O'Connor, Ryan T; Barr, James; Huang, Xiaohua; Wang, Yongmei

    2016-08-01

    Noble metal nanoparticles (NPs) such as silver (Ag) and gold (Au) have unique plasmonic properties that give rise to surface enhanced Raman scattering (SERS). Generally, Ag NPs have much stronger plasmonic properties and, hence, provide stronger SERS signals than Au NPs. However, Ag NPs lack the chemical stability and biocompatibility of comparable Au NPs and typically exhibit the most intense plasmonic resonance at wavelengths much shorter than the optimal spectral region for many biomedical applications. To overcome these issues, various experimental efforts have been devoted to the synthesis of Ag/Au hybrid NPs for the purpose of SERS detections. However, a complete understanding on how the SERS enhancement depends on the chemical composition and structure of these nanoparticles has not been achieved. In this study, Mie theory and the discrete dipole approximation have been used to calculate the plasmonic spectra and near-field electromagnetic enhancements of Ag/Au hybrid NPs. In particular, we discuss how the electromagnetic enhancement depends on the mole fraction of Au in Ag/Au alloy NPs and how one may use extinction spectra to distinguish between Ag/Au alloyed NPs and Ag-Au core-shell NPs. We also show that for incident laser wavelengths between ∼410 nm and 520 nm, Ag/Au alloyed NPs provide better electromagnetic enhancement than pure Ag, pure Au, or Ag-Au core-shell structured NPs. Finally, we show that silica-core Ag/Au alloy shelled NPs provide even better performance than pure Ag/Au alloy or pure solid Ag and pure solid Au NPs. The theoretical results presented will be beneficial to the experimental efforts in optimizing the design of Ag/Au hybrid NPs for SERS-based detection methods.

  12. Photocurrent generation in carbon nanotube/cubic-phase HfO2 nanoparticle hybrid nanocomposites

    Science.gov (United States)

    Galeckas, Augustinas; Salumaa, Martin; Ducroquet, Frédérique; Rauwel, Erwan

    2016-01-01

    Summary A hybrid material consisting of nonfunctionalized multiwall carbon nanotubes (MWCNTs) and cubic-phase HfO2 nanoparticles (NPs) with an average diameter of 2.6 nm has been synthesized. Free standing HfO2 NPs present unusual optical properties and a strong photoluminescence emission in the visible region, originating from surface defects. Transmission electron microscopy studies show that these NPs decorate the MWCNTs on topological defect sites. The electronic structure of the C K-edge in the nanocomposites was probed by electron energy loss spectroscopy, highlighting the key role of the MWCNT growth defects in anchoring HfO2 NPs. A combined optical emission and absorption spectroscopy approach illustrated that, in contrast to HfO2 NPs, the metallic MWCNTs do not emit light but instead expose their discrete electronic structure in the absorption spectra. The hybrid material manifests characteristic absorption features with a gradual merger of the MWCNT π-plasmon resonance band with the intrinsic defect band and fundamental edge of HfO2. The photoluminescence of the nanocomposites indicates features attributed to combined effects of charge desaturation of HfO2 surface states and charge transfer to the MWCNTs with an overall reduction of radiative recombination. Finally, photocurrent generation under UV–vis illumination suggests that a HfO2 NP/MWCNT hybrid system can be used as a flexible nanodevice for light harvesting applications. PMID:27547626

  13. Microwave-irradiation-assisted hybrid chemical approach for titanium dioxide nanoparticle synthesis: microbial and cytotoxicological evaluation.

    Science.gov (United States)

    Ranjan, Shivendu; Dasgupta, Nandita; Rajendran, Bhavapriya; Avadhani, Ganesh S; Ramalingam, Chidambaram; Kumar, Ashutosh

    2016-06-01

    Titanium dioxide nanoparticles (TNPs) are widely used in the pharmaceutical and cosmetics industries. It is used for protection against UV exposure due to its light-scattering properties and high refractive index. Though TNPs are increasingly used, the synthesis of TNPs is tedious and time consuming; therefore, in the present study, microwave-assisted hybrid chemical approach was used for TNP synthesis. In the present study, we demonstrated that TNPs can be synthesized only in 2.5 h; however, the commonly used chemical approach using muffle furnace takes 5 h. The activity of TNP depends on the synthetic protocol; therefore, the present study also determined the effect of microwave-assisted hybrid chemical approach synthetic protocol on microbial and cytotoxicity. The results showed that TNP has the best antibacterial activity in decreasing order from Escherichia coli, Bacillus subtilis, and Staphylococcus aureus. The IC50 values of TNP for HCT116 and A549 were found to be 6.43 and 6.04 ppm, respectively. Cell death was also confirmed from trypan blue exclusion assay and membrane integrity loss was observed. Therefore, the study determines that the microwave-assisted hybrid chemical approach is time-saving; hence, this technique can be upgraded from lab scale to industrial scale via pilot plant scale. Moreover, it is necessary to find the mechanism of action at the molecular level to establish the reason for greater bacterial and cytotoxicological toxicity. Graphical abstract A graphical representation of TNP synthesis.

  14. Hydrous ruthenium oxide nanoparticles anchored to graphene and carbon nanotube hybrid foam for supercapacitors.

    Science.gov (United States)

    Wang, Wei; Guo, Shirui; Lee, Ilkeun; Ahmed, Kazi; Zhong, Jiebin; Favors, Zachary; Zaera, Francisco; Ozkan, Mihrimah; Ozkan, Cengiz S

    2014-01-01

    In real life applications, supercapacitors (SCs) often can only be used as part of a hybrid system together with other high energy storage devices due to their relatively lower energy density in comparison to other types of energy storage devices such as batteries and fuel cells. Increasing the energy density of SCs will have a huge impact on the development of future energy storage devices by broadening the area of application for SCs. Here, we report a simple and scalable way of preparing a three-dimensional (3D) sub-5 nm hydrous ruthenium oxide (RuO2) anchored graphene and CNT hybrid foam (RGM) architecture for high-performance supercapacitor electrodes. This RGM architecture demonstrates a novel graphene foam conformally covered with hybrid networks of RuO2 nanoparticles and anchored CNTs. SCs based on RGM show superior gravimetric and per-area capacitive performance (specific capacitance: 502.78 F g(-1), areal capacitance: 1.11 F cm(-2)) which leads to an exceptionally high energy density of 39.28 Wh kg(-1) and power density of 128.01 kW kg(-1). The electrochemical stability, excellent capacitive performance, and the ease of preparation suggest this RGM system is promising for future energy storage applications. PMID:24663242

  15. Photocurrent generation in carbon nanotube/cubic-phase HfO2 nanoparticle hybrid nanocomposites.

    Science.gov (United States)

    Rauwel, Protima; Galeckas, Augustinas; Salumaa, Martin; Ducroquet, Frédérique; Rauwel, Erwan

    2016-01-01

    A hybrid material consisting of nonfunctionalized multiwall carbon nanotubes (MWCNTs) and cubic-phase HfO2 nanoparticles (NPs) with an average diameter of 2.6 nm has been synthesized. Free standing HfO2 NPs present unusual optical properties and a strong photoluminescence emission in the visible region, originating from surface defects. Transmission electron microscopy studies show that these NPs decorate the MWCNTs on topological defect sites. The electronic structure of the C K-edge in the nanocomposites was probed by electron energy loss spectroscopy, highlighting the key role of the MWCNT growth defects in anchoring HfO2 NPs. A combined optical emission and absorption spectroscopy approach illustrated that, in contrast to HfO2 NPs, the metallic MWCNTs do not emit light but instead expose their discrete electronic structure in the absorption spectra. The hybrid material manifests characteristic absorption features with a gradual merger of the MWCNT π-plasmon resonance band with the intrinsic defect band and fundamental edge of HfO2. The photoluminescence of the nanocomposites indicates features attributed to combined effects of charge desaturation of HfO2 surface states and charge transfer to the MWCNTs with an overall reduction of radiative recombination. Finally, photocurrent generation under UV-vis illumination suggests that a HfO2 NP/MWCNT hybrid system can be used as a flexible nanodevice for light harvesting applications. PMID:27547626

  16. Hydrous ruthenium oxide nanoparticles anchored to graphene and carbon nanotube hybrid foam for supercapacitors

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Wei [Univ. of California, Riverside, CA (United States); Guo, S. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Lee, I. [Univ. of California, Riverside, CA (United States); Ahmed, K. [Univ. of California, Riverside, CA (United States); Zhong, J. [Univ. of California, Riverside, CA (United States); Favors, Z. [Univ. of California, Riverside, CA (United States); Zaera, F. [Univ. of California, Riverside, CA (United States); Ozkan, M. [Univ. of California, Riverside, CA (United States); Ozkan, C. S [Univ. of California, Riverside, CA (United States)

    2014-03-25

    In real life applications, supercapacitors (SCs) often can only be used as part of a hybrid system together with other high energy storage devices due to their relatively lower energy density in comparison to other types of energy storage devices such as batteries and fuel cells. Increasing the energy density of SCs will have a huge impact on the development of future energy storage devices by broadening the area of application for SCs. Here, we report a simple and scalable way of preparing a three-dimensional (3D) sub-5 nm hydrous ruthenium oxide (RuO₂) anchored graphene and CNT hybrid foam (RGM) architecture for high-performance supercapacitor electrodes. This RGM architecture demonstrates a novel graphene foam conformally covered with hybrid networks of RuO₂ nanoparticles and anchored CNTs. SCs based on RGM show superior gravimetric and per-area capacitive performance (specific capacitance: 502.78 F g⁻¹, areal capacitance: 1.11 F cm⁻²) which leads to an exceptionally high energy density of 39.28 Wh kg⁻¹ and power density of 128.01 kW kg⁻¹. The electrochemical stability, excellent capacitive performance, and the ease of preparation suggest this RGM system is promising for future energy storage applications.

  17. Microwave-irradiation-assisted hybrid chemical approach for titanium dioxide nanoparticle synthesis: microbial and cytotoxicological evaluation.

    Science.gov (United States)

    Ranjan, Shivendu; Dasgupta, Nandita; Rajendran, Bhavapriya; Avadhani, Ganesh S; Ramalingam, Chidambaram; Kumar, Ashutosh

    2016-06-01

    Titanium dioxide nanoparticles (TNPs) are widely used in the pharmaceutical and cosmetics industries. It is used for protection against UV exposure due to its light-scattering properties and high refractive index. Though TNPs are increasingly used, the synthesis of TNPs is tedious and time consuming; therefore, in the present study, microwave-assisted hybrid chemical approach was used for TNP synthesis. In the present study, we demonstrated that TNPs can be synthesized only in 2.5 h; however, the commonly used chemical approach using muffle furnace takes 5 h. The activity of TNP depends on the synthetic protocol; therefore, the present study also determined the effect of microwave-assisted hybrid chemical approach synthetic protocol on microbial and cytotoxicity. The results showed that TNP has the best antibacterial activity in decreasing order from Escherichia coli, Bacillus subtilis, and Staphylococcus aureus. The IC50 values of TNP for HCT116 and A549 were found to be 6.43 and 6.04 ppm, respectively. Cell death was also confirmed from trypan blue exclusion assay and membrane integrity loss was observed. Therefore, the study determines that the microwave-assisted hybrid chemical approach is time-saving; hence, this technique can be upgraded from lab scale to industrial scale via pilot plant scale. Moreover, it is necessary to find the mechanism of action at the molecular level to establish the reason for greater bacterial and cytotoxicological toxicity. Graphical abstract A graphical representation of TNP synthesis. PMID:26976013

  18. Preventing sintering of Au and Ag nanoparticles in silica-based hybrid gels using phenyl spacer groups

    NARCIS (Netherlands)

    N.M. Wichner; J. Beckers; G. Rothenberg; H. Koller

    2010-01-01

    Gold and silver metal salts were reduced in the presence of phenylethylthiol as capping agent to form metal nanoparticles of 2.1-2.4 nm diameter. These clusters were then added to a sol-gel process using phenyltriethoxysilane as a hybrid component to optimize the dispersion of the metal particles in

  19. CaMoO4:TbatFe3O4 hybrid nanoparticles for luminescence and hyperthermia applications

    Science.gov (United States)

    Parchur, A. K.; Kaurav, N.; Ansari, A. A.; Prasad, A. I.; Ningthoujam, R. S.; Rai, S. B.

    2013-02-01

    We have prepared CaMoO4:Tb@Fe3O4 hybrid nanoparticles by co-precipitation and polyol method. Their temperature kinetics for hyperthermia temperature ˜43 °C under different applied AC fields and the luminescence properties under UV-radiation are investigated. A strong green emission is observed due to the presence of Tb3+ ions.

  20. Superhydrophobic hybrid films prepared from silica nanoparticles and ionic liquids via layer-by-layer self-assembly

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, Chenyun; Zhang, Shengnan; Gao, Picheng; Ma, Hongmin, E-mail: mahongmin2002@126.com; Wei, Qin

    2014-11-03

    The construction of superhydrophobic surfaces is of great interest in the fields of materials science and engineering. In this work, a class of hybrid thin films with controlled wetting property was prepared from silica nanoparticles and an ionic liquid via layer-by-layer self-assembly. Positively charged ionic liquid 1-dodecyl-3-methylimidazoliumbromide ([C{sub 12}mim]Br) and negatively charged silica nanoparticles were alternatively adsorbed onto glass substrates. The silica nanoparticles were characterized by transmission electron microscopy, and the hybrid films were characterized by scanning electron microscope and X-ray photoelectron spectroscopy. The wetting property of the bulk films was examined by water contact angle measurements. The hydrophobicity of surfaces originated from the formation of nanostructure and the hydrophobic property of the ionic liquid. The change in the layer numbers, concentration of NH{sub 3}·H{sub 2}O and the type of silica precursor (tetramethoxysilane and tetraethoxysilane) could control the wettability. Under the optimum layer numbers and size of SiO{sub 2}, a superhydrophobic (SiO{sub 2}/[C{sub 12}mim]Br){sub 13} hybrid film with a contact angle of 152.3 ± 5.0° was obtained. - Highlights: • The combination of inorganic nanoparticles and ionic liquids • Superhydrophobic hybrid thin films with controlled wetting property • Layer-by-layer self-assembled nanostructures • Stability in superhydrophobic properties.

  1. Superhydrophobic hybrid films prepared from silica nanoparticles and ionic liquids via layer-by-layer self-assembly

    International Nuclear Information System (INIS)

    The construction of superhydrophobic surfaces is of great interest in the fields of materials science and engineering. In this work, a class of hybrid thin films with controlled wetting property was prepared from silica nanoparticles and an ionic liquid via layer-by-layer self-assembly. Positively charged ionic liquid 1-dodecyl-3-methylimidazoliumbromide ([C12mim]Br) and negatively charged silica nanoparticles were alternatively adsorbed onto glass substrates. The silica nanoparticles were characterized by transmission electron microscopy, and the hybrid films were characterized by scanning electron microscope and X-ray photoelectron spectroscopy. The wetting property of the bulk films was examined by water contact angle measurements. The hydrophobicity of surfaces originated from the formation of nanostructure and the hydrophobic property of the ionic liquid. The change in the layer numbers, concentration of NH3·H2O and the type of silica precursor (tetramethoxysilane and tetraethoxysilane) could control the wettability. Under the optimum layer numbers and size of SiO2, a superhydrophobic (SiO2/[C12mim]Br)13 hybrid film with a contact angle of 152.3 ± 5.0° was obtained. - Highlights: • The combination of inorganic nanoparticles and ionic liquids • Superhydrophobic hybrid thin films with controlled wetting property • Layer-by-layer self-assembled nanostructures • Stability in superhydrophobic properties

  2. Holey graphene/polypyrrole nanoparticle hybrid aerogels with three-dimensional hierarchical porous structure for high performance supercapacitor

    Science.gov (United States)

    He, Yibo; Bai, Yonglong; Yang, Xiaofan; Zhang, Jinyang; Kang, Liping; Xu, Hua; Shi, Feng; Lei, Zhibin; Liu, Zong-Huai

    2016-06-01

    Holey graphene/polypyrrole hybrid aerogels (HGPAs) with three-dimensional (3D) hierarchical structure have been fabricated by freeze-drying holey graphene/polypyrrole hydrogels, which are assembled by using holey graphene (HG) nanosheets and polypyrrole (PPy) nanoparticles as assembling primitives. The as-prepared HGPAs materials show an interconnected and stable 3D porous network, and PPy nanoparticles uniformly embedded in the aerogel prevent the restacking of holey graphene (HG) nanosheets. The unique hierarchical porous structure and synergistic effect between PPy nanoparticles and HG nanosheets make HGPA hybrid aerogel electrode with a mass ratio of PPy/HGO = 0.75 exhibits high specific capacitance (418 F g-1) at a current density of 0.5 A g-1, extremely outstanding rate capability (80%) at various current densities from 0.5 to 20 A g-1 and good cycling performance (74%) after 2000 cycles in 1.0 M KOH aqueous electrolyte. Moreover, the effect of the PPy nanoparticle sizes in HGPAs on their electrochemical properties is also investigated, and PPy nanoparticles with relatively larger sizes are favorable of the good capacitive performance for the obtained electrodes. The facile and efficient preparation method for HGPAs electrodes may be developed for preparing other holey graphene-based hybrid aerogels with structure-controllable nanostructures.

  3. Effect of natural extracts pH on morphological characteristics of hybrid materials based on gold nanoparticles

    Science.gov (United States)

    Olenic, L.; Vulcu, A.; Chiorean, I.; Crisan, M.; Berghian-Grosan, C.; Dreve, S.; David, L.; Tudoran, L. B.; Kacso, I.; Bratu, I.; Neamtu, C.; Voica, C.

    2013-11-01

    In the present paper we have investigated the pH influence on the morphology of some new hybrid materials based on gold nanoparticles and natural extracts from fruits of Romanian native plants of Adoxaceae family (Viburnum opulus L. and Sambucus nigra L.). It is well known that the natural plants extracts are beneficial for humans thanks to their antioxidant, anti-inflammatory and immunomodulatory effects. The biological activity of these berries is mainly due to their high content of anthocyanins and other polyphenols. The nanoparticles facilitate the penetration of substances in skin, enhancing their antimitotic, anti-inflammatory and antibiotic properties. We have chosen the optimal method to get these materials in which gold nanoparticles of 10-80 nm were obtained. We characterized them by UV-Vis and FT-IR spectroscopy, by TEM and DSC. Creams prepared with the hybrid materials have been tested on psoriatic lesions and the medical results emphasized a remarkable improvement in this diseases.

  4. In vitro performance of lipid-PLGA hybrid nanoparticles as an antigen delivery system: lipid composition matters

    Science.gov (United States)

    Hu, Yun; Ehrich, Marion; Fuhrman, Kristel; Zhang, Chenming

    2014-08-01

    Due to the many beneficial properties combined from both poly(lactic-co-glycolic acid) (PLGA) nanoparticles (NPs) and liposomes, lipid-PLGA hybrid NPs have been intensively studied as cancer drug delivery systems, bio-imaging agent carriers, as well as antigen delivery vehicles. However, the impact of lipid composition on the performance of lipid-PLGA hybrid NPs as a delivery system has not been well investigated. In this study, the influence of lipid composition on the stability of the hybrid NPs and in vitro antigen release from NPs under different conditions was examined. The uptake of hybrid NPs with various surface charges by dendritic cells (DCs) was carefully studied. The results showed that PLGA NPs enveloped by a lipid shell with more positive surface charges could improve the stability of the hybrid NPs, enable better controlled release of antigens encapsulated in PLGA NPs, as well as enhance uptake of NPs by DC.

  5. Magnetic and optical properties of Ag@SiO2-FITC-Fe3O4 hybrid nanoparticles

    International Nuclear Information System (INIS)

    Highlights: • New magnetic/fluorescent nanoparticles were synthesized. • The silver core led to a maximum 4-fold enhanced fluorescence of fluorophore. • Maximum enhancement factor was obtained when metal-fluorophore distance is 5 nm. • Magnetism and fluorescence appeared simultaneously for nanoparticles in solution. -- Abstract: Nanoparticles composed of a silver core coated with a silica shell (Ag@SiO2) were prepared. A dye, fluorescein isothiocyanate (FITC), was further encapsulated during the growth of a second silica shell onto Ag@SiO2 nanoparticles. The proximity of silver nanoparticles led to a 4-fold maximal enhancement in the fluorescence of FITC when the first silica shell thickness was set at 5 nm. After amino-functionalization of Ag@SiO2-FITC nanoparticles, iron oxide nanoparticles were bonded to their surface. The magnetic and metal-enhanced fluorescence properties appeared simultaneously when Ag@SiO2-FITC-Fe3O4 hybrid nanoparticles were dispersed in a solution

  6. Receptor-mediated membrane adhesion of lipid-polymer hybrid (LPH) nanoparticles studied by dissipative particle dynamics simulations

    Science.gov (United States)

    Li, Zhenlong; Gorfe, Alemayehu A.

    2014-12-01

    Lipid-polymer hybrid (LPH) nanoparticles represent a novel class of targeted drug delivery platforms that combine the advantages of liposomes and biodegradable polymeric nanoparticles. However, the molecular details of the interaction between LPHs and their target cell membranes remain poorly understood. We have investigated the receptor-mediated membrane adhesion process of a ligand-tethered LPH nanoparticle using extensive dissipative particle dynamics (DPD) simulations. We found that the spontaneous adhesion process follows a first-order kinetics characterized by two distinct stages: a rapid nanoparticle-membrane engagement, followed by a slow growth in the number of ligand-receptor pairs coupled with structural re-organization of both the nanoparticle and the membrane. The number of ligand-receptor pairs increases with the dynamic segregation of ligands and receptors toward the adhesion zone causing an out-of-plane deformation of the membrane. Moreover, the fluidity of the lipid shell allows for strong nanoparticle-membrane interactions to occur even when the ligand density is low. The LPH-membrane avidity is enhanced by the increased stability of each receptor-ligand pair due to the geometric confinement and the cooperative effect arising from multiple binding events. Thus, our results reveal the unique advantages of LPH nanoparticles as active cell-targeting nanocarriers and provide some general principles governing nanoparticle-cell interactions that may aid future design of LPHs with improved affinity and specificity for a given target of interest.

  7. Facile preparation of TiO2-polyvinyl alcohol hybrid nanoparticles with improved visible light photocatalytic activity

    Science.gov (United States)

    Filippo, Emanuela; Carlucci, Claudia; Capodilupo, Agostina Lina; Perulli, Patrizia; Conciauro, Francesca; Corrente, Giuseppina Anna; Gigli, Giuseppe; Ciccarella, Giuseppe

    2015-03-01

    Hybrid inorganic/organic core/shell nanoparticles were prepared through a two step synthesis procedure. In the first step, pure anatase TiO2 nanoparticles were synthesized though a rapid microwave assisted non-aqueous route. Then, the obtained titania nanoparticles were coated with polyvinyl alcohol (PVA) using a simple solution method followed by relatively low temperature treatment. The PVA-coated titania nanoparticles samples were prepared at different TiO2-PVA weight ratio and they were characterized using X-Ray diffraction, transmission electron microscopy, infrared spectroscopy and Brunauer-Emmett-Teller (BET) analysis. Photocatalytic performance was also evaluated for all samples and the results indicated that TiO2:PVA weight ratio was a key factor to obtain an improvement of the photocatalytic activity with respect to bare TiO2 nanoparticles, since PVA concentration influenced the surface area and the aggregation of nanoparticles and the thickness of the coating layer. This inexpensive system provides a simple, quick and effective approach which allows to obtain core/shell hybrid nanostructures.

  8. Fabrication of Carbon Nanotube/SiO2and Carbon Nanotube/SiO2/Ag Nanoparticles Hybrids by Using Plasma Treatment

    Directory of Open Access Journals (Sweden)

    Li Haiqing

    2009-01-01

    Full Text Available Abstract Based on plasma-treated single wall carbon nanotubes (SWCNTs, SWCNT/SiO2and thiol groups-functionalized SWCNT/SiO2hybrids have been fabricated through a sol–gel process. By means of thiol groups, Ag nanoparticles have been in situ synthesized and bonded onto the SiO2shell of SWCNT/SiO2in the absence of external reducing agent, resulting in the stable carbon nanotube/SiO2/Ag nanoparticles hybrids. This strategy provides a facile, low–cost, and green methodology for the creation of carbon nanotube/inorganic oxides-metal nanoparticles hybrids.

  9. Stability in the memory state of the silica nanoparticle-doped hybrid aligned nematic device

    Science.gov (United States)

    Huang, Chi-Yen; Chen, Jian-Hong; Hsieh, Chia-Ting; Song, Heng-Cheng; Wang, Yu-Wu; Horng, Lance; Tian, Ching-Jui; Hwang, Shug-June

    2011-01-01

    We investigate the stability in the memory state of the silica nanoparticle doped hybrid aligned nematic (SN-HAN) cell. The mixed polyimide (PI)-coated planar substrate provides the SN-HAN cell with a stable memory state. The mixed PI comprises the homogeneous PI and small amounts of the homeotropic PI (H-PI). The tiny H-PI dopant decreases the surface energy, increases the roughness of the planar substrate, and increases the pretilt angle of the liquid crystals (LCs). When the pretilt angle is high, the relaxation torque that rewinds the LCs from the electrically addressed homeotropic state to the originally HAN state is too small to break the formed aggregated silica networks, which stabilize the LCs at the electrically addressed homeotropic state. Consequently, the memory state of the SN-HAN cell is stable when the pretilt angle of the LCs is high.

  10. Engineered Protein Polymer-Gold Nanoparticle Hybrid Materials for Small Molecule Delivery

    Science.gov (United States)

    Dai, Min; Frezzo, JA; Sharma, E; Chen, R; Singh, N; Yuvienco, C; Caglar, E; Xiao, S; Saxena, A; Montclare, JK

    2016-01-01

    We have fabricated protein polymer-gold nanoparticle (P-GNP) nanocomposites that exhibit enhanced binding and delivery properties of the small hydrophobic molecule drug, curcumin, to the model breast cancer cell line, MCF-7. These hybrid biomaterials are constructed via in situ GNP templated-synthesis with genetically engineered histidine tags. The P-GNP nanocomposites exhibit enhanced small molecule loading, sustained release and increased uptake by MCF-7 cells. When compared to the proteins polymers alone, the P-GNPs demonstrate a greater than 7-fold increase in curcumin binding, a nearly 50% slower release profile and more than 2-fold increase in cellular uptake of curcumin. These results suggest that P-GNP nanocomposites serve as promising candidates for drug delivery vehicles. PMID:27081576

  11. Solid-state dye-sensitized solar cells based on ZnO nanoparticle and nanorod array hybrid photoanodes

    Directory of Open Access Journals (Sweden)

    Sue Hung-Jue

    2011-01-01

    Full Text Available Abstract The effect of ZnO photoanode morphology on the performance of solid-state dye-sensitized solar cells (DSSCs is reported. Four different structures of dye-loaded ZnO layers have been fabricated in conjunction with poly(3-hexylthiophene. A significant improvement in device efficiency with ZnO nanorod arrays as photoanodes has been achieved by filling the interstitial voids of the nanorod arrays with ZnO nanoparticles. The overall power conversion efficiency increases from 0.13% for a nanorod-only device to 0.34% for a device with combined nanoparticles and nanorod arrays. The higher device efficiency in solid-state DSSCs with hybrid nanorod/nanoparticle photoanodes is originated from both large surface area provided by nanoparticles for dye adsorption and efficient charge transport provided by the nanorod arrays to reduce the recombinations of photogenerated carriers.

  12. Synthesis and surface immobilization of antibacterial hybrid silver-poly(l-lactide) nanoparticles

    Science.gov (United States)

    Taheri, Shima; Baier, Grit; Majewski, Peter; Barton, Mary; Förch, Renate; Landfester, Katharina; Vasilev, Krasimir

    2014-08-01

    Infections associated with medical devices are a substantial healthcare problem. Consequently, there has been increasing research and technological efforts directed toward the development of coatings that are capable of preventing bacterial colonization of the device surface. Herein, we report on novel hybrid silver loaded poly(L-lactic acid) nanoparticles (PLLA-AgNPs) with narrowly distributed sizes (17 ± 3 nm) prepared using a combination of solvent evaporation and mini-emulsion technology. These particles were then immobilized onto solid surfaces premodified with a thin layer of allylamine plasma polymer (AApp). The antibacterial efficacy of the PLLA-AgNPs nanoparticles was studied in vitro against both gram-positive (Staphylococcus epidermidis) and gram-negative (Escherichia coli) bacteria. The minimal inhibitory concentration values against Staphylococcus epidermidis and Escherichia coli were 0.610 and 1.156 μg · mL-1, respectively. The capacity of the prepared coatings to prevent bacterial surface colonization was assessed in the presence of Staphylococcus epidermidis, which is a strong biofilm former that causes substantial problems with medical device associated infections. The level of inhibition of bacterial growth was 98%. The substrate independent nature and the high antibacterial efficacy of coatings presented in this study may offer new alternatives for antibacterial coatings for medical devices.

  13. Transparent superhydrophobic/translucent superamphiphobic coatings based on silica-fluoropolymer hybrid nanoparticles.

    Science.gov (United States)

    Lee, Seung Goo; Ham, Dong Seok; Lee, Dong Yun; Bong, Hyojin; Cho, Kilwon

    2013-12-01

    This paper describes a simple approach to prepare a transparent superhydrophobic coating and a translucent superamphiphobic coating via spraying silica-fluoropolymer hybrid nanoparticles (SFNs) without any pre- or post-treatment of substrates; these nanoparticles create both microscale and nanoscale roughness, and fluoropolymer acts as a low surface energy binder. We also demonstrate the effects of varying the concentration of the SFN sol on the water and hexadecane repellency and on the transparency of the coated glass substrates. An increase in the concentration of the sol facilitates the transition between the superhydrophobic/transparent and superamphiphobic/translucent states. This transition results from an increase in the discontinuities in the three-phase (solid-liquid-gas) contact line and in the light scattering properties due to micropapillae tuned by varying the concentration of the sol. This versatile and controllable approach can be applied to a variety of substrates over large areas and may provide a wide range of applications for self-cleaning coatings of optoelectronics, liquid-repellent coatings, and microfluidic systems.

  14. Transparent superhydrophobic/translucent superamphiphobic coatings based on silica-fluoropolymer hybrid nanoparticles.

    Science.gov (United States)

    Lee, Seung Goo; Ham, Dong Seok; Lee, Dong Yun; Bong, Hyojin; Cho, Kilwon

    2013-12-01

    This paper describes a simple approach to prepare a transparent superhydrophobic coating and a translucent superamphiphobic coating via spraying silica-fluoropolymer hybrid nanoparticles (SFNs) without any pre- or post-treatment of substrates; these nanoparticles create both microscale and nanoscale roughness, and fluoropolymer acts as a low surface energy binder. We also demonstrate the effects of varying the concentration of the SFN sol on the water and hexadecane repellency and on the transparency of the coated glass substrates. An increase in the concentration of the sol facilitates the transition between the superhydrophobic/transparent and superamphiphobic/translucent states. This transition results from an increase in the discontinuities in the three-phase (solid-liquid-gas) contact line and in the light scattering properties due to micropapillae tuned by varying the concentration of the sol. This versatile and controllable approach can be applied to a variety of substrates over large areas and may provide a wide range of applications for self-cleaning coatings of optoelectronics, liquid-repellent coatings, and microfluidic systems. PMID:24224524

  15. A RNA-DNA Hybrid Aptamer for Nanoparticle-Based Prostate Tumor Targeted Drug Delivery

    Directory of Open Access Journals (Sweden)

    John C. Leach

    2016-03-01

    Full Text Available The side effects of radio- and chemo-therapy pose long-term challenges on a cancer patient’s health. It is, therefore, highly desirable to develop more effective therapies that can specifically target carcinoma cells without damaging normal and healthy cells. Tremendous efforts have been made in the past to develop targeted drug delivery systems for solid cancer treatment. In this study, a new aptamer, A10-3-J1, which recognizes the extracellular domain of the prostate specific membrane antigen (PSMA, was designed. A super paramagnetic iron oxide nanoparticle-aptamer-doxorubicin (SPIO-Apt-Dox was fabricated and employed as a targeted drug delivery platform for cancer therapy. This DNA RNA hybridized aptamer antitumor agent was able to enhance the cytotoxicity of targeted cells while minimizing collateral damage to non-targeted cells. This SPIO-Apt-Dox nanoparticle has specificity to PSMA+ prostate cancer cells. Aptamer inhibited nonspecific uptake of membrane-permeable doxorubic to the non-target cells, leading to reduced untargeted cytotoxicity and endocytic uptake while enhancing targeted cytotoxicity and endocytic uptake. The experimental results indicate that the drug delivery platform can yield statistically significant effectiveness being more cytotoxic to the targeted cells as opposed to the non-targeted cells.

  16. Hybrid Molecular and Spin Dynamics Simulations for Ensembles of Magnetic Nanoparticles for Magnetoresistive Systems

    Directory of Open Access Journals (Sweden)

    Lisa Teich

    2015-11-01

    Full Text Available The development of magnetoresistive sensors based on magnetic nanoparticles which are immersed in conductive gel matrices requires detailed information about the corresponding magnetoresistive properties in order to obtain optimal sensor sensitivities. Here, crucial parameters are the particle concentration, the viscosity of the gel matrix and the particle structure. Experimentally, it is not possible to obtain detailed information about the magnetic microstructure, i.e., orientations of the magnetic moments of the particles that define the magnetoresistive properties, however, by using numerical simulations one can study the magnetic microstructure theoretically, although this requires performing classical spin dynamics and molecular dynamics simulations simultaneously. Here, we present such an approach which allows us to calculate the orientation and the trajectory of every single magnetic nanoparticle. This enables us to study not only the static magnetic microstructure, but also the dynamics of the structuring process in the gel matrix itself. With our hybrid approach, arbitrary sensor configurations can be investigated and their magnetoresistive properties can be optimized.

  17. A RNA-DNA Hybrid Aptamer for Nanoparticle-Based Prostate Tumor Targeted Drug Delivery

    Science.gov (United States)

    Leach, John C.; Wang, Andrew; Ye, Kaiming; Jin, Sha

    2016-01-01

    The side effects of radio- and chemo-therapy pose long-term challenges on a cancer patient’s health. It is, therefore, highly desirable to develop more effective therapies that can specifically target carcinoma cells without damaging normal and healthy cells. Tremendous efforts have been made in the past to develop targeted drug delivery systems for solid cancer treatment. In this study, a new aptamer, A10-3-J1, which recognizes the extracellular domain of the prostate specific membrane antigen (PSMA), was designed. A super paramagnetic iron oxide nanoparticle-aptamer-doxorubicin (SPIO-Apt-Dox) was fabricated and employed as a targeted drug delivery platform for cancer therapy. This DNA RNA hybridized aptamer antitumor agent was able to enhance the cytotoxicity of targeted cells while minimizing collateral damage to non-targeted cells. This SPIO-Apt-Dox nanoparticle has specificity to PSMA+ prostate cancer cells. Aptamer inhibited nonspecific uptake of membrane-permeable doxorubic to the non-target cells, leading to reduced untargeted cytotoxicity and endocytic uptake while enhancing targeted cytotoxicity and endocytic uptake. The experimental results indicate that the drug delivery platform can yield statistically significant effectiveness being more cytotoxic to the targeted cells as opposed to the non-targeted cells. PMID:26985893

  18. Development of a lauric acid/albumin hybrid iron oxide nanoparticle system with improved biocompatibility.

    Science.gov (United States)

    Zaloga, Jan; Janko, Christina; Nowak, Johannes; Matuszak, Jasmin; Knaup, Sabine; Eberbeck, Dietmar; Tietze, Rainer; Unterweger, Harald; Friedrich, Ralf P; Duerr, Stephan; Heimke-Brinck, Ralph; Baum, Eva; Cicha, Iwona; Dörje, Frank; Odenbach, Stefan; Lyer, Stefan; Lee, Geoffrey; Alexiou, Christoph

    2014-01-01

    The promising potential of superparamagnetic iron oxide nanoparticles (SPIONs) in various nanomedical applications has been frequently reported. However, although many different synthesis methods, coatings, and functionalization techniques have been described, not many core-shell SPION drug delivery systems are available for clinicians at the moment. Here, bovine serum albumin was adsorbed onto lauric acid-stabilized SPIONs. The agglomeration behavior, zeta potential, and their dependence on the synthesis conditions were characterized with dynamic light scattering. The existence and composition of the core-shell-matrix structure was investigated by transmission electron microscopy, Fourier transform infrared spectroscopy, and zeta potential measurements. We showed that the iron oxide cores form agglomerates in the range of 80 nm. Moreover, despite their remarkably low tendency to aggregate even in a complex media like whole blood, the SPIONs still maintained their magnetic properties and were well attractable with a magnet. The magnetic properties were quantified by vibrating sample magnetometry and a superconducting quantum interference device. Using flow cytometry, we further investigated the effects of the different types of nanoparticle coating on morphology, viability, and DNA integrity of Jurkat cells. We showed that by addition of bovine serum albumin, the toxicity of nanoparticles is greatly reduced. We also investigated the effect of the particles on the growth of primary human endothelial cells to further demonstrate the biocompatibility of the particles. As proof of principle, we showed that the hybrid-coated particles are able to carry payloads of up to 800 μg/mL of the cytostatic drug mitoxantrone while still staying colloidally stable. The drug-loaded system exhibited excellent therapeutic potential in vitro, exceeding that of free mitoxantrone. In conclusion, we have synthesized a biocompatible ferrofluid that shows great potential for clinical

  19. Biomimetic synthesis of raspberry-like hybrid polymer-silica core-shell nanoparticles by templating colloidal particles with hairy polyamine shell.

    Science.gov (United States)

    Pi, Mengwei; Yang, Tingting; Yuan, Jianjun; Fujii, Syuji; Kakigi, Yuichi; Nakamura, Yoshinobu; Cheng, Shiyuan

    2010-07-01

    The nanoparticles composed of polystyrene core and poly[2-(diethylamino)ethyl methacrylate] (PDEA) hairy shell were used as colloidal templates for in situ silica mineralization, allowing the well-controlled synthesis of hybrid silica core-shell nanoparticles with raspberry-like morphology and hollow silica nanoparticles by subsequent calcination. Silica deposition was performed by simply stirring a mixture of the polymeric core-shell particles in isopropanol, tetramethyl orthosilicate (TMOS) and water at 25 degrees C for 2.5h. No experimental evidence was found for nontemplated silica formation, which indicated that silica deposition occurred exclusively in the PDEA shell and formed PDEA-silica hybrid shell. The resulting hybrid silica core-shell particles were characterized by transmission electron microscopy (TEM), thermogravimetry, aqueous electrophoresis, and X-ray photoelectron spectroscopy. TEM studies indicated that the hybrid particles have well-defined core-shell structure with raspberry morphology after silica deposition. We found that the surface nanostructure of hybrid nanoparticles and the composition distribution of PDEA-silica hybrid shell could be well controlled by adjusting the silicification conditions. These new hybrid core-shell nanoparticles and hollow silica nanoparticles would have potential applications for high-performance coatings, encapsulation and delivery of active organic molecules. PMID:20347275

  20. Biomimetic synthesis of raspberry-like hybrid polymer-silica core-shell nanoparticles by templating colloidal particles with hairy polyamine shell.

    Science.gov (United States)

    Pi, Mengwei; Yang, Tingting; Yuan, Jianjun; Fujii, Syuji; Kakigi, Yuichi; Nakamura, Yoshinobu; Cheng, Shiyuan

    2010-07-01

    The nanoparticles composed of polystyrene core and poly[2-(diethylamino)ethyl methacrylate] (PDEA) hairy shell were used as colloidal templates for in situ silica mineralization, allowing the well-controlled synthesis of hybrid silica core-shell nanoparticles with raspberry-like morphology and hollow silica nanoparticles by subsequent calcination. Silica deposition was performed by simply stirring a mixture of the polymeric core-shell particles in isopropanol, tetramethyl orthosilicate (TMOS) and water at 25 degrees C for 2.5h. No experimental evidence was found for nontemplated silica formation, which indicated that silica deposition occurred exclusively in the PDEA shell and formed PDEA-silica hybrid shell. The resulting hybrid silica core-shell particles were characterized by transmission electron microscopy (TEM), thermogravimetry, aqueous electrophoresis, and X-ray photoelectron spectroscopy. TEM studies indicated that the hybrid particles have well-defined core-shell structure with raspberry morphology after silica deposition. We found that the surface nanostructure of hybrid nanoparticles and the composition distribution of PDEA-silica hybrid shell could be well controlled by adjusting the silicification conditions. These new hybrid core-shell nanoparticles and hollow silica nanoparticles would have potential applications for high-performance coatings, encapsulation and delivery of active organic molecules.

  1. Amino Acid-Dependent Attenuation of Toll-like Receptor Signaling by Peptide-Gold Nanoparticle Hybrids.

    Science.gov (United States)

    Yang, Hong; Fung, Shan-Yu; Xu, Shuyun; Sutherland, Darren P; Kollmann, Tobias R; Liu, Mingyao; Turvey, Stuart E

    2015-07-28

    Manipulation of immune responsiveness using nanodevices provides a potential approach to treat human diseases. Toll-like receptor (TLR) signaling plays a central role in the pathophysiology of many acute and chronic human inflammatory diseases, and pharmacological regulation of TLR responses is anticipated to be beneficial in many of these inflammatory conditions. Here we describe the discovery of a unique class of peptide-gold nanoparticle hybrids that exhibit a broad inhibitory activity on TLR signaling, inhibiting signaling through TLRs 2, 3, 4, and 5. As exemplified using TLR4, the nanoparticles were found to inhibit both arms of TLR4 signaling cascade triggered by the prototypical ligand, lipopolysaccharide (LPS). Through structure-activity relationship studies, we identified the key chemical components of the hybrids that contribute to their immunomodulatory activity. Specifically, the hydrophobicity and aromatic ring structure of the amino acids on the peptides were essential for modulating TLR4 responses. This work enhances our fundamental understanding of the role of nanoparticle surface chemistry in regulating innate immune signaling, and identifies specific nanoparticle hybrids that may represent a unique class of anti-inflammatory therapeutics for human inflammatory diseases.

  2. Hybrid-Type Organic Thermoelectric Materials Containing Nanoparticles as a Carrier Transport Promoter

    Science.gov (United States)

    Oshima, Keisuke; Inoue, Junta; Sadakata, Shifumi; Shiraishi, Yukihide; Toshima, Naoki

    2016-08-01

    Carbon nanotubes (CNTs) have recently received much attention as thermoelectric materials. Although the carrier mobility within a single CNT is very high, the charge carrier transport between CNTs is quite slow. We have utilized nanoparticles (NPs) for promotion of the carrier transport between CNTs for improving their thermoelectric performance. Poly(vinyl chloride) (PVC) was used as a binder of the CNTs. Thus, hybrid-type organic thermoelectric materials containing the NPs were constructed from Pd NPs, CNTs, and PVC. The thermoelectric properties were slightly improved in the three-component films by only mixing the separately-prepared Pd NPs. The NPs of a polymer complex, poly(nickel 1,1,2,2-ethenetetrathiolate) (n-PETT), were also used as a charge carrier transport promoter instead of the Pd NPs to produce n-PETT/CNT/PVC hybrid films. Treatment of the three-component films with methanol produced a high thermoelectric power factor and low thermal conductivity, resulting in a high "apparent" thermoelectric performance (ZT ˜ 0.3 near room temperature) although the thermal conductivity was measured in the through-plane direction, which is a different direction from that for the electrical conductivity.

  3. Gating capacitive field-effect sensors by the charge of nanoparticle/molecule hybrids.

    Science.gov (United States)

    Poghossian, Arshak; Bäcker, Matthias; Mayer, Dirk; Schöning, Michael J

    2015-01-21

    The semiconductor field-effect platform is a powerful tool for chemical and biological sensing with direct electrical readout. In this work, the field-effect capacitive electrolyte-insulator-semiconductor (EIS) structure - the simplest field-effect (bio-)chemical sensor - modified with citrate-capped gold nanoparticles (AuNPs) has been applied for a label-free electrostatic detection of charged molecules by their intrinsic molecular charge. The EIS sensor detects the charge changes in AuNP/molecule inorganic/organic hybrids induced by the molecular adsorption or binding events. The feasibility of the proposed detection scheme has been exemplarily demonstrated by realizing capacitive EIS sensors consisting of an Al-p-Si-SiO2-silane-AuNP structure for the label-free detection of positively charged cytochrome c and poly-d-lysine molecules as well as for monitoring the layer-by-layer formation of polyelectrolyte multilayers of poly(allylamine hydrochloride)/poly(sodium 4-styrene sulfonate), representing typical model examples of detecting small proteins and macromolecules and the consecutive adsorption of positively/negatively charged polyelectrolytes, respectively. For comparison, EIS sensors without AuNPs have been investigated, too. The adsorption of molecules on the surface of AuNPs has been verified via the X-ray photoelectron spectroscopy method. In addition, a theoretical model of the functioning of the capacitive field-effect EIS sensor functionalized with AuNP/charged-molecule hybrids has been discussed. PMID:25470772

  4. Dual Transient Bleaching of Au/PbS Hybrid Core/Shell Nanoparticles.

    Science.gov (United States)

    Kobayashi, Yoichi; Nonoguchi, Yoshiyuki; Wang, Li; Kawai, Tsuyoshi; Tamai, Naoto

    2012-05-01

    We examined the optical response of hybrid Au/PbS core/shell nanoparticles (NPs) using transient absorption spectroscopy. Finite-difference time-domain (FDTD) calculations and transient absorption measurements show that Au/PbS NPs have unique two extinction peaks: the peak at the longer wavelength (∼700 nm) is originated from the plasmon, and that at the shorter wavelength (550 nm) is from the local maximum of the refractive index of PbS. The transient absorption dynamics of Au/PbS NPs excited at 400 nm have clear oscillation behavior, which is assigned to the breathing mode of whole particle. We observed a weak excitation-wavelength dependence of the plasmon band. The time constant of electron-phonon coupling of Au/PbS NPs was obtained by changing the excitation intensity. We show that spectral properties of Au/PbS NPs are strongly altered by the hybrid formations, while their dynamics differ only minimally compared with those of Au NPs. PMID:26288045

  5. Polythiophene-gold nanoparticle hybrid systems: Langmuir-Blodgett assembly of nanostructured films.

    Science.gov (United States)

    Jayaraman, Sundaramurthy; Yu, Liew Ting; Srinivasan, M P

    2013-04-01

    In this work, we demonstrate a simple method of synthesizing nanoscale polythiophene-gold nanoparticle (AuNP) hybrid systems assembled by the Langmuir-Blodgett (LB) method. Regio-regular poly(3-(2-methoxyethoxy)ethoxymethyl)thiophene-2,5-diyl (PMEEMT) and poly(3-dodecylthiophene) (PDDT) were employed as the polymeric constituents. The presence of PDDT improved the amphiphilicity of PMEEMT by addressing the phase separation that occurred due to convective hydrodynamic instability on the substrate. 4 layer stacks of 90% and 99% PMEEMT films exhibited uniform film structure with a significant reduction in phase separation. A detailed mechanism for minimization of the surface effect has been proposed based on the interaction of polythiophenes with the substrate. For the first time, an ex situ approach has been adopted to incorporate AuNPs into LB films without affecting the film morphology and uniformity. The incorporation of AuNPs into the polythiophene matrix, aided by the affinity of sulphur for gold, was strongly dependent on the molecular arrangement of the matrix, which in turn depended on the composition of the matrix. The hybrid polythiophene films exhibited enhanced conductivity and can be applied in sensors, photovoltaics and memory devices.

  6. Optical and electrical effects of plasmonic nanoparticles in high-efficiency hybrid solar cells.

    Science.gov (United States)

    Fu, Wei-Fei; Chen, Xiaoqiang; Yang, Xi; Wang, Ling; Shi, Ye; Shi, Minmin; Li, Han-Ying; Jen, Alex K-Y; Chen, Jun-Wu; Cao, Yong; Chen, Hong-Zheng

    2013-10-28

    Plasmonics have been proven to be an effective way to harness more incident light to achieve high efficiency in photovoltaic devices. Herein, we explore the possibility that plasmonics can be utilized to enhance light trapping and power conversion efficiency (PCE) for polymer-quantum dot (QD) hybrid solar cells (HSCs). Based on a low band-gap polymer poly[2,6-(4,4-bis-(2-ethylhexyl)-4H-cyclopenta[2,1-b;3,4-b']-dithiophene)-alt-4,7-(2,1,3-benzothiadiazole)] (PCPDTBT) and a CdSe QD bulk-heterojunction (BHJ) system, gold nanoparticles were doped at different locations of the devices. Successfully, an improved PCE of 3.20 ± 0.22% and 3.16 ± 0.15% was achieved by doping the hole transporting layer and the active layer, respectively, which are among the highest values reported for CdSe QD based HSCs. A detailed study of processing, characterization, microscopy, and device fabrication is conducted to understand the underlying mechanism for the enhanced device performance. The success of this work provides a simple and generally applicable approach to enhance light harnessing of polymer-QD hybrid solar cells. PMID:24006000

  7. Effect of Refractive Index of Substrate on Fabrication and Optical Properties of Hybrid Au-Ag Triangular Nanoparticle Arrays

    Directory of Open Access Journals (Sweden)

    Jing Liu

    2015-05-01

    Full Text Available In this study, the nanosphere lithography (NSL method was used to fabricate hybrid Au-Ag triangular periodic nanoparticle arrays. The Au-Ag triangular periodic arrays were grown on different substrates, and the effect of the refractive index of substrates on fabrication and optical properties was systematically investigated. At first, the optical spectrum was simulated by the discrete dipole approximation (DDA numerical method as a function of refractive indexes of substrates and mediums. Simulation results showed that as the substrates had the refractive indexes of 1.43 (quartz and 1.68 (SF5 glass, the nanoparticle arrays would have better refractive index sensitivity (RIS and figure of merit (FOM. Simulation results also showed that the peak wavelength of the extinction spectra had a red shift when the medium’s refractive index n increased. The experimental results also demonstrated that when refractive indexes of substrates were 1.43 and 1.68, the nanoparticle arrays and substrate had better adhesive ability. Meanwhile, we found the nanoparticles formed a large-scale monolayer array with the hexagonally close-packed structure. Finally, the hybrid Au-Ag triangular nanoparticle arrays were fabricated on quartz and SF5 glass substrates and their experiment extinction spectra were compared with the simulated results.

  8. Magnetic-responsive hybrids of Fe3O4 nanoparticles with β-lactoglobulin amyloid fibrils and nanoclusters.

    Science.gov (United States)

    Bolisetty, Sreenath; Vallooran, Jijo J; Adamcik, Jozef; Mezzenga, Raffaele

    2013-07-23

    We report on the synthesis and magnetic-responsive behavior of hybrids formed by dispersing negatively charged iron oxide (Fe3O4) magnetic nanoparticles in positively charged β-lactoglobulin protein solutions at acidic pH, followed by heating at high temperatures. Depending on the pH used, different hybrid aggregates can be obtained, such as nanoparticle-modified amyloid fibrils (pH 3) and spherical nanoclusters (pH 4.5). We investigate the effect of magnetic fields of varying strengths (0-5 T) on the alignment of these Fe3O4-modified amyloid fibrils and spherical nanoclusters using a combination of scattering, birefringence and microscopic techniques and we find a strong alignment of the hybrids upon increasing the intensity of the magnetic field, which we quantify via 2D and 3D order parameters. We also demonstrate the possibility of controlling magnetically the sol-gel behavior of these hybrids: addition of salt (NaCl, 150 mM) to a solution containing nanoparticles modified with β-lactoglobulin amyloid fibrils (2 wt % fibrils modified with 0.6 wt % Fe3O4 nanoparticles) induces first the formation of a reversible gel, which can then be converted back to solution upon application of a moderate magnetic field of 1.1 T. These hybrids offer a new appealing functional colloidal system in which the aggregation, orientational order and rheological behavior can be efficiently controlled in a purely noninvasive way by external magnetic fields of weak intensity.

  9. Hemolysin coregulated protein 1 as a molecular gluing unit for the assembly of nanoparticle hybrid structures.

    Science.gov (United States)

    Pham, Tuan Anh; Schreiber, Andreas; Sturm Née Rosseeva, Elena V; Schiller, Stefan; Cölfen, Helmut

    2016-01-01

    Hybrid nanoparticle (NP) structures containing organic building units such as polymers, peptides, DNA and proteins have great potential in biosensor and electronic applications. The nearly free modification of the polymer chain, the variation of the protein and DNA sequence and the implementation of functional moieties provide a great platform to create inorganic structures of different morphology, resulting in different optical and magnetic properties. Nevertheless, the design and modification of a protein structure with functional groups or sequences for the assembly of biohybrid materials is not trivial. This is mainly due to the sensitivity of its secondary, tertiary and quaternary structure to the changes in the interaction (e.g., hydrophobic, hydrophilic, electrostatic, chemical groups) between the protein subunits and the inorganic material. Here, we use hemolysin coregulated protein 1 (Hcp1) from Pseudomonas aeruginosa as a building and gluing unit for the formation of biohybrid structures by implementing cysteine anchoring points at defined positions on the protein rim (Hcp1_cys3). We successfully apply the Hcp1_cys3 gluing unit for the assembly of often linear, hybrid structures of plasmonic gold (Au NP), magnetite (Fe3O4 NP), and cobalt ferrite nanoparticles (CoFe2O4 NP). Furthermore, the assembly of Au NPs into linear structures using Hcp1_cys3 is investigated by UV-vis spectroscopy, TEM and cryo-TEM. One key parameter for the formation of Au NP assembly is the specific ionic strength in the mixture. The resulting network-like structure of Au NPs is characterized by Raman spectroscopy, showing surface-enhanced Raman scattering (SERS) by a factor of 8·10(4) and a stable secondary structure of the Hcp1_cys3 unit. In order to prove the catalytic performance of the gold hybrid structures, they are used as a catalyst in the reduction reaction of 4-nitrophenol showing similar catalytic activity as the pure Au NPs. To further extend the functionality of the

  10. Development of a lauric acid/albumin hybrid iron oxide nanoparticle system with improved biocompatibility

    Directory of Open Access Journals (Sweden)

    Zaloga J

    2014-10-01

    interference device. Using flow cytometry, we further investigated the effects of the different types of nanoparticle coating on morphology, viability, and DNA integrity of Jurkat cells. We showed that by addition of bovine serum albumin, the toxicity of nanoparticles is greatly reduced. We also investigated the effect of the particles on the growth of primary human endothelial cells to further demonstrate the biocompatibility of the particles. As proof of principle, we showed that the hybrid-coated particles are able to carry payloads of up to 800 µg/mL of the cytostatic drug mitoxantrone while still staying colloidally stable. The drug-loaded system exhibited excellent therapeutic potential in vitro, exceeding that of free mitoxantrone. In conclusion, we have synthesized a biocompatible ferrofluid that shows great potential for clinical application. The synthesis is straightforward and reproducible and thus easily translatable into a good manufacturing practice environment. Keywords: iron oxide nanoparticles, drug delivery, protein corona, magnetic drug targeting, colloidal stability

  11. Synthesis and Applications of Multimodal Hybrid Albumin Nanoparticles for Chemotherapeutic Drug Delivery and Photothermal Therapy Platforms

    Science.gov (United States)

    Peralta, Donna V.

    cellular uptake of AuNR-HSAPs via fluorescence microscopy. Finally, camptothecin (CPT) an antineoplastic agent and BACPT (7-butyl-10-aminocamptothecin) were loaded into HSAPs to combat their aqueous insolubility. BACPT-HSAPs loaded up to 5.25 micrograms BACPT/ mg of HSA. CPT encapsulation could not be determined. BACPT-HSAPs and CPT-HSAPs showed cytotoxicity to human sarcoma cells in vitro. Key words: Hybrid Nanoparticles, Photothermal Therapy, Gold Nanomaterials, Drug Delivery, Combinational Cancer Therapies, Materials, Human Serum Albumin, Colloidal Carriers.

  12. Fabrication and study of properties of magnetite nanoparticles in hybrid micelles of polystyrene-block-polyethylene oxide and sodium dodecyl sulfate

    Energy Technology Data Exchange (ETDEWEB)

    Loginova, T. P., E-mail: tlg@ineos.ac.ru; Timofeeva, G. I.; Lependina, O. L.; Shandintsev, V. A. [Russian Academy of Sciences, Nesmeyanov Institute of Organoelement Compounds (Russian Federation); Matyushin, A. A. [Ministry of Public Health of the Russian Federation, First Moscow State Medical University (Russian Federation); Khotina, I. A. [Russian Academy of Sciences, Nesmeyanov Institute of Organoelement Compounds (Russian Federation); Shtykova, E. V. [Russian Academy of Sciences, Shubnikov Institute of Crystallography (Russian Federation)

    2016-01-15

    Magnetite nanoparticles have been formed for the first time in hybrid micelles of polystyrene-block-polyethylene oxide and sodium dodecyl sulfate in water by ultrasonic treatment at room temperature. An analysis by small-angle X-ray scattering and transmission electron microscopy (TEM) showed that magnetite nanoparticles in hybrid micelles of block copolymer and sodium dodecyl sulfate are polydesperse (have sizes from 0.5 to 20 nm). The specific magnetization of solid samples has been measured.

  13. Fabrication and study of properties of magnetite nanoparticles in hybrid micelles of polystyrene- block-polyethylene oxide and sodium dodecyl sulfate

    Science.gov (United States)

    Loginova, T. P.; Timofeeva, G. I.; Lependina, O. L.; Shandintsev, V. A.; Matyushin, A. A.; Khotina, I. A.; Shtykova, E. V.

    2016-01-01

    Magnetite nanoparticles have been formed for the first time in hybrid micelles of polystyrene- block-polyethylene oxide and sodium dodecyl sulfate in water by ultrasonic treatment at room temperature. An analysis by small-angle X-ray scattering and transmission electron microscopy (TEM) showed that magnetite nanoparticles in hybrid micelles of block copolymer and sodium dodecyl sulfate are polydesperse (have sizes from 0.5 to 20 nm). The specific magnetization of solid samples has been measured.

  14. The hybrid of SnO2 nanoparticle and polypyrrole aerogel: an excellent electromagnetic wave absorbing materials

    Science.gov (United States)

    Wang, Yu; Dai, Xiaoqing; Jiang, Wanchun; Wu, Fan; Xie, Aming

    2016-07-01

    As a kind of costless and lightweight material, SnO2 nanoparticles@polypyrrole hybrid aerogels have been synthesized and displayed electromagnetic wave absorbing (EWA) performance. Only with 10 wt% of nano-SnO2 filler loading in wax, effective EWA bandwidth of the hybrid aerogel can reach 7.28 GHz which is the widest lightweight EWA material among the reported absorbents. Through the regulation of sample thicknesses, effective EWA at lower frequencies can also be achieved. It was demonstrated that this aerogel can be used as an effective lightweight broadband EWA material.

  15. Photocatalytic Reactive Oxygen Species Formation by Semiconductor-Metal Hybrid Nanoparticles. Toward Light-Induced Modulation of Biological Processes.

    Science.gov (United States)

    Waiskopf, Nir; Ben-Shahar, Yuval; Galchenko, Michael; Carmel, Inbal; Moshitzky, Gilli; Soreq, Hermona; Banin, Uri

    2016-07-13

    Semiconductor-metal hybrid nanoparticles manifest efficient light-induced spatial charge separation at the semiconductor-metal interface, as demonstrated by their use for hydrogen generation via water splitting. Here, we pioneer a study of their functionality as efficient photocatalysts for the formation of reactive oxygen species. We observed enhanced photocatalytic activity forming hydrogen peroxide, superoxide, and hydroxyl radicals upon light excitation, which was significantly larger than that of the semiconductor nanocrystals, attributed to the charge separation and the catalytic function of the metal tip. We used this photocatalytic functionality for modulating the enzymatic activity of horseradish peroxidase as a model system, demonstrating the potential use of hybrid nanoparticles as active agents for controlling biological processes through illumination. The capability to produce reactive oxygen species by illumination on-demand enhances the available peroxidase-based tools for research and opens the path for studying biological processes at high spatiotemporal resolution, laying the foundation for developing novel therapeutic approaches. PMID:27224678

  16. A hybrid-assembly approach towards nitrogen-doped graphene aerogel supported cobalt nanoparticles as high performance oxygen reduction electrocatalysts.

    Science.gov (United States)

    Liu, Ruili; Jin, Yeqing; Xu, Peimin; Xing, Xia; Yang, Yuxing; Wu, Dongqing

    2016-02-15

    As a novel electrocatalyst for oxygen reduction reaction (ORR), nitrogen-doped graphene aerogel supported cobalt nanoparticles (Co-NGA) is archived by a hybrid-assembly of graphene oxide (GO), o-phthalonitrile and cobalt acetate and the following thermal treatment. The hybrid-assembly process successfully combines the ionic assembly of GO sheets and Co ions with the coordination between o-phthalonitrile and Co ions, which can be converted to nitrogen doped carbon and Co nanoparticles in the pyrolysis process under nitrogen flow. Remarkable features of Co-NGA including the macroporous graphene scaffolds, high surface area, and N/Co-doping effect can lead to a high catalytic efficiency for ORR. As the results, the composites pyrolyzed at 600°C (Co-NGA600) shows excellent electrocatalytic activities and kinetics for ORR in basic media, which are comparable with those of Pt/C catalyst, together with superior durability.

  17. Three-dimensional graphene/metal oxide nanoparticle hybrids for high-performance capacitive deionization of saline water.

    Science.gov (United States)

    Yin, Huajie; Zhao, Shenlong; Wan, Jiawei; Tang, Hongjie; Chang, Lin; He, Liangcan; Zhao, Huijun; Gao, Yan; Tang, Zhiyong

    2013-11-20

    A novel and general method is proposed to construct three-dimensional graphene/metal oxide nanoparticle hybrids. For the first time, it is demonstrated that this graphene-based composite with open pore structures can be used as the high-performance capacitive deionization (CDI) electrode materials, which outperform currently reported materials. This work will offer a promising way to develop highly effective CDI electrode materials. PMID:23963808

  18. Nanocomposite thin films for miniaturized multi-ayer ceramic capacitors prepared from barium titanate nanoparticle based hybrid solutions

    OpenAIRE

    Schneller, T.; Halder, S; Waser, R.; Pithan, C.; Dornseiffer, J.; Shiratori, Y; Houben, L.; Vyshnavi, N.; Majumber, S.B.

    2011-01-01

    In the present work a flexible approach for the wet chemical processing of nanocomposite functional thin films is demonstrated. Barium titanate (BTO) based nanocomposite thin films for future miniaturized multi-layer ceramic capacitors are chosen as model systems to introduce the concept of "hybrid solutions" which consist of stabile mixtures of reverse micelle derived BTO nanoparticle dispersions and conventional molecular precursor solutions of either the same (BTO:BTO) or a specifically di...

  19. Effect of Refractive Index of Substrate on Fabrication and Optical Properties of Hybrid Au-Ag Triangular Nanoparticle Arrays

    OpenAIRE

    Jing Liu; Yushan Chen; Haoyuan Cai; Xiaoyi Chen; Changwei Li; Cheng-Fu Yang

    2015-01-01

    In this study, the nanosphere lithography (NSL) method was used to fabricate hybrid Au-Ag triangular periodic nanoparticle arrays. The Au-Ag triangular periodic arrays were grown on different substrates, and the effect of the refractive index of substrates on fabrication and optical properties was systematically investigated. At first, the optical spectrum was simulated by the discrete dipole approximation (DDA) numerical method as a function of refractive indexes of substrates and mediums. S...

  20. Nucleation and Growth of Ordered Arrays of Silver Nanoparticles on Peptide Nanofibers: Hybrid Nanostructures with Antimicrobial Properties.

    Science.gov (United States)

    Pazos, Elena; Sleep, Eduard; Rubert Pérez, Charles M; Lee, Sungsoo S; Tantakitti, Faifan; Stupp, Samuel I

    2016-05-01

    Silver nanoparticles have been of great interest as plasmonic substrates for sensing and imaging, catalysts, or antimicrobial systems. Their physical properties are strongly dependent on parameters that remain challenging to control such as size, chemical composition, and spatial distribution. We report here on supramolecular assemblies of a novel peptide amphiphile containing aldehyde functionality in order to reduce silver ions and subsequently nucleate silver metal nanoparticles in water. This system spontaneously generates monodisperse silver particles at fairly regular distances along the length of the filamentous organic assemblies. The metal-organic hybrid structures exhibited antimicrobial activity and significantly less toxicity toward eukaryotic cells. Metallized organic nanofibers of the type described here offer the possibility to create hydrogels, which integrate the useful functions of silver nanoparticles with controllable metallic content. PMID:27103596

  1. Controlled association and delivery of nanoparticles from jet-sprayed hybrid microfibrillar matrices.

    Science.gov (United States)

    Keloglu, Nermin; Verrier, Bernard; Trimaille, Thomas; Sohier, Jérôme

    2016-04-01

    To develop bioactive scaffolds of targeted properties for tissue repair or biomedical applications, hybrid microfiber-nanoparticle (MF-NP) matrices capable of controlled nanoparticle (NP) delivery were prepared through two novel approaches. In a first strategy, the suppleness of the jet-spraying method to produce polymer microfibers (MF) was used to deposit poly(d,l-lactide) (PLA) NP on poly(lactic-co-glycolic acid) (PLGA) MF by direct co-projection. The second approach relied on the post-incubation of PLA NP aqueous dispersion with MF preliminarily prepared by jet-spraying. NP coverage density onto MF and NP release was assessed by scanning electron microscopy and fluorescence measurements using coumarin-6 loaded NP. The first process was shown to allow high coverage density of NP onto MF (300 μg/mg MF) and strong association, with no NP release observed over time. In the second approach, direct incubation of PLA NP with PLA MF led to lower NP coverage density (40 μg/mg MF) with very fast release of NP from MF. The pre-coating of MF with poly-l-lysine (PLL) or the one of NP with lysozyme as a model protein drug afforded a higher coverage density and stronger association, coupled with a more sustained release of NP from MF over time. These results show the possibility to control the immobilization density and release of NP through appropriate preparation process and surface modification, and are of prime interest for the development of complex scaffolds with orchestrated bioactivity. PMID:26752211

  2. Metal-Semiconductor Nanoparticle Hybrids Formed by Self-Organization: A Platform to Address Exciton-Plasmon Coupling.

    Science.gov (United States)

    Strelow, Christian; Theuerholz, T Sverre; Schmidtke, Christian; Richter, Marten; Merkl, Jan-Philip; Kloust, Hauke; Ye, Ziliang; Weller, Horst; Heinz, Tony F; Knorr, Andreas; Lange, Holger

    2016-08-10

    Hybrid nanosystems composed of excitonic and plasmonic constituents can have different properties than the sum of of the two constituents, due to the exciton-plasmon interaction. Here, we report on a flexible model system based on colloidal nanoparticles that can form hybrid combinations by self-organization. The system allows us to tune the interparticle distance and to combine nanoparticles of different sizes and thus enables a systematic investigation of the exciton-plasmon coupling by a combination of optical spectroscopy and quantum-optical theory. We experimentally observe a strong influence of the energy difference between exciton and plasmon, as well as an interplay of nanoparticle size and distance on the coupling. We develop a full quantum theory for the luminescence dynamics and discuss the experimental results in terms of the Purcell effect. As the theory describes excitation as well as coherent and incoherent emission, we also consider possible quantum optical effects. We find a good agreement of the observed and the calculated luminescence dynamics induced by the Purcell effect. This also suggests that the self-organized hybrid system can be used as platform to address quantum optical effects.

  3. Biocompatible hybrid nanomaterials involving polymers and hydrogels interfaced with phosphorescent complexes and toxin-free metallic nanoparticles for biomedical applications

    Science.gov (United States)

    Marpu, Sreekar B.

    The major topics discussed are all relevant to interfacing brightly phosphorescent and non-luminescent coinage metal complexes of [Ag(I) and Au(I)] with biopolymers and thermoresponsive gels for making hybrid nanomaterials with an explanation on syntheses, characterization and their significance in biomedical fields. Experimental results and ongoing work on determining outreaching consequences of these hybrid nanomaterials for various biomedical applications like cancer therapy, bio-imaging and antibacterial abilities are described. In vitro and in vivo studies have been performed on majority of the discussed hybrid nanomaterials and determined that the cytotoxicity or antibacterial activity are comparatively superior when compared to analogues in literature. Consequential differences are noticed in photoluminescence enhancement from hybrid phosphorescent hydrogels, phosphorescent complex ability to physically crosslink, Au(I) sulfides tendency to form NIR (near-infrared) absorbing AuNPs compared to any similar work in literature. Syntheses of these hybrid nanomaterials has been thoroughly investigated and it is determined that either metallic nanoparticles syntheses or syntheses of phosphorescent hydrogels can be carried in single step without involving any hazardous reducing agents or crosslinkers or stabilizers that are commonly employed during multiple step syntheses protocols for syntheses of similar materials in literature. These astounding results that have been discovered within studies of hybrid nanomaterials are an asset to applications ranging from materials development to health science and will have striking effect on environmental and green chemistry approaches.

  4. Facile method to synthesize magnetic iron oxides/TiO2 hybrid nanoparticles and their photodegradation application of methylene blue

    Directory of Open Access Journals (Sweden)

    Wu Wei

    2011-01-01

    Full Text Available Abstract Many methods have been reported to improving the photocatalytic efficiency of organic pollutant and their reliable applications. In this work, we propose a facile pathway to prepare three different types of magnetic iron oxides/TiO2 hybrid nanoparticles (NPs by seed-mediated method. The hybrid NPs are composed of spindle, hollow, and ultrafine iron oxide NPs as seeds and 3-aminopropyltriethyloxysilane as linker between the magnetic cores and TiO2 layers, respectively. The composite structure and the presence of the iron oxide and titania phase have been confirmed by transmission electron microscopy, X-ray diffraction, and X-ray photoelectron spectra. The hybrid NPs show good magnetic response, which can get together under an external applied magnetic field and hence they should become promising magnetic recovery catalysts (MRCs. Photocatalytic ability examination of the magnetic hybrid NPs was carried out in methylene blue (MB solutions illuminated under Hg light in a photochemical reactor. About 50% to 60% of MB was decomposed in 90 min in the presence of magnetic hybrid NPs. The synthesized magnetic hybrid NPs display high photocatalytic efficiency and will find recoverable potential applications in cleaning polluted water with the help of magnetic separation.

  5. Hybrid ZnO nanowire/a-Si:H thin-film radial junction solar cells using nanoparticle front contacts

    Energy Technology Data Exchange (ETDEWEB)

    Pathirane, M., E-mail: minoli.pathirane@uwaterloo.ca; Iheanacho, B.; Lee, C.-H.; Wong, W. S. [Department of Electrical and Computer Engineering, University of Waterloo, 200 University Avenue West, Waterloo, Ontario N2L 3G1 (Canada); Tamang, A.; Knipp, D. [Research Center for Functional Materials and Nanomolecular Science, Jacobs University Bremen, Bremen 28759 (Germany); Lujan, R. [Electronic Materials and Devices Laboratory, Palo Alto Research Center, Palo Alto, California 93003 (United States)

    2015-10-05

    Hydrothermally synthesized disordered ZnO nanowires were conformally coated with a-Si:H thin-films to fabricate three dimensional hybrid nanowire/thin-film structures. The a-Si:H layer formed a radial junction p-i-n diode solar cell around the ZnO nanowire. The cylindrical hybrid solar cells enhanced light scattering throughout the UV-visible-NIR spectrum (300 nm–800 nm) resulting in a 22% increase in short-circuit current density compared to the reference planar p-i-n device. A fill factor of 69% and a total power conversion efficiency of 6.5% were achieved with the hybrid nanowire solar cells using a spin-on indium tin oxide nanoparticle suspension as the top contact.

  6. Gold Nanoparticle-based Layer-by-Layer Enhancement of DNA Hybridization Electrochemical Signal at Carbon Nanotube Modified Carbon Paste Electrode

    Institute of Scientific and Technical Information of China (English)

    Li Bo NIE; Jian Rong CHEN; Yu Qing MIAO; Nong Yue HE

    2006-01-01

    Colloid gold nanoparticle-based layer-by-layer amplification approach was applied to enhance the electrochemical detection sensitivity of DNA hybridization at carbon nanotube modified carbon paste electrodes (CNTPEs). Streptavidin was immobilized onto the surface of CNTPEs, and the conjugation of biotin labeled target oligonucleotides to the above immobilized streptavidin was performed, followed by the hybridization of target oligonucleotides with the gold nanoparticle-labeled DNA probe and then the layer-by-layer enhanced connection of gold nanoparticles, on which oligonucleotides complementary to the DNA probe were attached, to the hybridization system. The differential pulse voltammetry (DPV) signal of total gold nanoparticles was monitored. It was found that the layer-by-layer colloidal gold DPV detection enhanced the sensitivity by about one order of magnitude compared with that of one-layer detection. One-base mismatched DNA and complementary DNA could be distinguished clearly.

  7. Single Nanometric Memory Unit Based On a Protein-Nanoparticle Hybrid

    Science.gov (United States)

    Medalsy, Izhar; Heyman, Arnon; Shoseyov, Oded; Porath, Danny

    2009-03-01

    Proteins as an isolating template and nanoparticle (NP) as an electric storage component can form a single addressable unit cell isolated from the conductive surface and adjacent NPs. This setup gives rise to a wide range of nanoelectronic applications. Here we demonstrate, by Conductive AFM, a single nanometric memory unit using individual protein-NP hybrids. SP1 is a boiling-stable ring-shaped protein, 11 nm in diameter. Mutants of SP1 were synthesized allowing its selective attachment to gold surface and the formation of 2D arrays using methods such as phospholipids trough and Langmuir Blodgett. The SP1 inner pore was connected to Si NP forming a chargeable entity embedded in an isolating unit over a conductive surface. Each NP holds three charging states: natural, positive and negative. The charging life times are 10 min in ambient and days in vacuum. Using this setup, and the relative long charging time, we were able to apply a read and write operations on individual 5nm Si NP embedded in a stable protein.

  8. Synthesis of zinc oxide nanoparticles on graphene-carbon nanotube hybrid for glucose biosensor applications.

    Science.gov (United States)

    Hwa, Kuo-Yuan; Subramani, Boopathi

    2014-12-15

    Synthesis of zinc oxide nanoparticles incorporated graphene-carbon nanotubes hybrid (GR-CNT-ZnO) through a simple, one-pot method is demonstrated. The as-synthesized GR-CNT-ZnO composite is applied to fabricate an enzyme based glucose biosensor. The GOx immobilized on GR-CNT-ZnO composite exhibits well-defined redox peaks with a peak potential separation (ΔEp) of about 26 mV with enhanced peak currents, indicating a fast electron transfer at the modified electrode surface. The cyclic voltammetry measurements revealed that the modified film has high electrocatalytic ability towards glucose detection in the presence of oxygen. The proposed sensor has a wide linear detection range from 10 μM to 6.5 mM of glucose with a limit of detection (LOD) of 4.5 (±0.08) μM. In addition, the sensor possessed appreciable repeatability, reproducibility and remarkable stability for the sensitive determination of glucose. The practicality of this sensor has been demonstrated in human serum samples, with results being in good agreement with those determined using a standard photometric method. PMID:24997365

  9. Gold nanoparticle/carbon nanotube hybrids as an enhanced material for sensitive amperometric determination of tryptophan

    Energy Technology Data Exchange (ETDEWEB)

    Guo Yujing [State Key Laboratory of Electroanalytical Chemistry, Changchun Institute of Applied Chemistry, Chinese Academy of Sciences, Renmin Street 5625, Changchun 130022, Jilin (China); Research Center for Environmental Science and Engineering, Shanxi University, Taiyuan 030006 (China); Guo Shaojun; Fang Youxing [State Key Laboratory of Electroanalytical Chemistry, Changchun Institute of Applied Chemistry, Chinese Academy of Sciences, Renmin Street 5625, Changchun 130022, Jilin (China); Dong Shaojun, E-mail: dongsj@ciac.jl.c [State Key Laboratory of Electroanalytical Chemistry, Changchun Institute of Applied Chemistry, Chinese Academy of Sciences, Renmin Street 5625, Changchun 130022, Jilin (China)

    2010-04-30

    In this work, a highly sensitive electrochemical sensor for the determination of tryptophan (Trp) was fabricate by electrodeposition of gold nanoparticles (AuNPs) onto carbon nanotube (CNT) films pre-cast on a glassy carbon electrode (GCE), forming an AuNP-CNT composite-modified GCE (AuNP-CNT/GCE). Scanning electron microscopy (SEM), electrochemical impedance spectroscopy (EIS) and cyclic voltammetry (CV) were used for the surface analysis of the electrode. The results indicate that the hybrid nanomaterials induced a substantial decrease in the overpotential of the Trp oxidation reaction and exhibited a remarkable synergistic effect on the electrocatalytic activity toward the oxidation of Trp. In phosphate buffer solution (pH 7.4), the modified electrode showed excellent analytical performance for the amperometric determination of Trp. The peak currents possess a linear relationship with the concentration of Trp in the range of 30 nM to 2.5 muM, and the detection limit is 10 nM (S/N = 3). In addition, the modified electrode was used to determine Trp concentration in pharmaceutical samples with satisfactory results.

  10. High surface enhanced Raman scattering activity of BN nanosheets–Ag nanoparticles hybrids

    Energy Technology Data Exchange (ETDEWEB)

    Yang, Shanshan; Zhang, Zhaochun, E-mail: zhangzhaochun@shu.edu.cn; Zhao, Jun; Zheng, Houli

    2014-01-15

    Highlights: • Boron nitride–silver nanohybrid was acquired through a liquid-phase reducing route. • The composite shown a high-quality SERS activity. • 2-Mercaptobenzimidazole was chemisorbed on silver surface in vertical orientation. -- Abstract: A facile liquid-phase reducing route was developed to modify boron nitride (BN) nanosheets with silver nanoparticles (AgNPs) in order to fabricate BN–AgNPs hybrids with high surface enhanced Raman scattering (SERS) activity. The layered structure and morphology of BN–AgNPs nanohybrids were characterized by transmission electron microscopy and atomic force microscopy, meanwhile, Fourier transform infrared spectroscopy and ultraviolet–visible were used for studying optical properties and surface plasmon resonance applied to the optical sensor. The SERS of adsorbed 2-mercaptobenzimidazole (MBI) molecule was investigated which shown that the BN–AgNPs substrate exhibited a very strong SERS activity, offering a great potential application in molecular probe sensor. On the basis of the analysis of SERS and the Raman surface selection rules, we could draw a conclusion that the MBI molecule was adsorbed upright on the AgNPs surface through the sulphur and nitrogen atoms. What is more, the cyclic voltammetry experiment indicated the electrochemically irreversible behavior of BN–AgNPs nanohybrids in KCl solution.

  11. Large 2D-arrays of size-controllable silver nanoparticles prepared by hybrid deposition

    Science.gov (United States)

    Dieu Thuy Ung, Thi; Hoa Nguyen, Thi; Liem Nguyen, Quang

    2016-09-01

    Two main results are presented in this paper. (i) Silver nanoparticles (AgNPs) with uniform size-distribution and controllability in the range of 20-50 nm were synthesized by seeding and growing at ambient conditions. The single-crystal Ag nano-seeds were created by reduction of AgNO3 in presence of citrate surfactant at 70 °C. Then, importantly, the fresh AgCl precursor was used in the presence of polyvinylpyrrolidone to adjust the reaction rate with ascorbic acid to generate Ag for growing on the surface of single-crystal Ag nano-seeds. The AgNPs size could be well-controlled by varying the amount of Ag nano-seeds while keeping the AgCl precursor concentration to be constant. (ii) The large 2D-arrays with homogeneous and dense monolayers of AgNPs were prepared on ITO substrates by hybrid method, in which the key technological point is the surface functionalization of AgNPs using mixed alkanethiols (dodecanethiol:octadecanethiol = 6:1). We have used the fabricated 2D-arrays from the 50 nm AgNPs as a surface enhanced Raman scattering substrate to take the Raman scattering spectra of rhodamine B (RhB), glucose and viral pathogen (H5N1) at very low concentrations of 10-10 M, 10-12 M and 4 ng μl-1, respectively.

  12. Hybrid palm-oil/styrene-maleimide nanoparticles synthesized in aqueous dispersion under different conditions.

    Science.gov (United States)

    Samyn, Pieter; Van Nieuwkerke, Dieter; Schoukens, Gustaaf; Stanssens, Dirk; Vonck, Leo; Van den Abbeele, Henk

    2015-01-01

    Poly(styrene-co-maleic anhydride) was imidized with ammonium hydroxide and palm oil, resulting in an aqueous dispersion of hybrid nanoparticles with diameters 85-180 nm (dispersed) or 20-50 nm (dried). The reaction conditions were optimized for different precursors by evaluating the relative amount ammonium hydroxide and maximizing the incorporated palm oil up to 70 wt.%. The interactions between palm oil and polymer phase have been studied by TEM, IR, Raman spectroscopy and thermal analysis (TGA, [TM] DSC). From Raman spectra, the amount of imide and reacted oil were quantified. Through concurring effects of imidization and coupling of fatty acids, the imidization needs a slight excess of NH3 relatively to maleic anhydride. The oxidative stability highly depends on oxidative crosslinking of free or non-reacted oil. Comparing the imide content from spectroscopic and thermal analysis suggests that a complex rigid imide phase without strong relaxation behavior has formed in combination with oil.

  13. Development of Novel Polymer-Lipid Hybrid Nanoparticles of Tamoxifen: In Vitro and In Vivo Evaluation.

    Science.gov (United States)

    Varthya, Mansingh; Pawar, Harish; Singh, Charan; Dora, Chander Parkash; Jena, Sunil Kumar; Suresh, Sarasija

    2016-01-01

    This study was undertaken to develop and investigate the effect of tamoxifen polymer-lipid hybrid nanoparticles (Tmx-PLN) on its oral bioavailability and efficacy in the 7,12-dimethylbenzanthracene (DMBA)-induced breast cancer model. Modified solvent emulsification-evaporation method was optimized to obtain Tmx-PLN, composed of chitosan and lecithin, of 169.66 ± 4.84 nm particle size. The PLN exhibited prolonged in vitro release in phosphate-buffered saline. Further, PLN displayed enhanced oral bioavailability with considerable increase in AUC (1277.46 vs. 585.01 ng/ml · h), pro- longed t½ (27.87 ± 15.62 vs. 10.18 ± 6.5 h) and mean residence time (40.11 ± 25.72 vs. 17.42 ± 12.04 h) in comparison to pure Tmx. In addition, PLN exhibited significantly increased (P < 0.05) antitumor efficacy in DMBA-induced breast cancer model, when administered once in three days in comparison to Tmx daily dosing. This enhancement may be attributed to a probable reduction in Pgp efflux, decreased first-pass metabolism and lymphatic drug transport. Thus, Tmx-PLN exhibited enhanced potential to increase Tmx therapeutic efficacy in chronic treatment of breast cancer. PMID:27398452

  14. Electrochemical determination of cysteine based on conducting polymers/gold nanoparticles hybrid nanocomposites

    Energy Technology Data Exchange (ETDEWEB)

    Hsiao, Ya-Ping; Su, Wan-Yu; Cheng, Jin-Ru [Department of Applied Chemistry, National Chi Nan University, Puli, Nantou Hsien 545, Taiwan (China); Cheng, Shu-Hua, E-mail: shcheng@ncnu.edu.t [Department of Applied Chemistry, National Chi Nan University, Puli, Nantou Hsien 545, Taiwan (China)

    2011-08-01

    In this study, a hybrid nanocomposite consisting of a conducting polymer and gold nanoparticles (AuNPs) is fabricated onto a screen-printed carbon electrode (SPCE). A thin layer of poly(3,4-ethylenedioxythiophene) (PEDOT) is coated electrochemically on a bare SPCE; then, the nano-sized AuNPs are embedded by electrochemical deposition. The resultant SPCE/PEDOT/AuNPs-modified electrode is characterized by electrochemical methods, field emission scanning electron microscopy (FE-SEM) and X-ray photoelectron spectroscopy (XPS). The SPCE/PEDOT/AuNPs-modified electrode possesses great catalytic activity for the oxidation of cysteine in various pH buffer solutions (pH 2.0-8.0). The selectivity of the method is demonstrated by the separation of the oxidation peaks at up to 240 mV for cysteine and glutathione in pH 6.0 buffer solutions. The effects of the oxidizable interferences are also investigated. Flow-injection amperometry is performed for 0.5-200 {mu}M of cysteine in pH 4.0 buffer solutions, and a linear calibration plot with a slope of 0.115 {mu}A/{mu}M is obtained. The detection limit (S/N = 3) is 0.05 {mu}M. Additionally, the proposed methods obtain satisfactory results in the detection of cysteine-containing medicine samples.

  15. Hybridized plasmon modes and near-field enhancement of metallic nanoparticle-dimer on a mirror

    Science.gov (United States)

    Huang, Yu; Ma, Lingwei; Hou, Mengjing; Li, Jianghao; Xie, Zheng; Zhang, Zhengjun

    2016-07-01

    For the attractive plasmonic structure consisting of metal nanoparticles (NPs) on a mirror, the coexistence of near-field NP-NP and NP-mirror couplings is numerically studied at normal incidence. By mapping their 3D surface charge distributions directly, we have demonstrated two different kinds of mirror-induced bonding dipole plasmon modes and confirmed the bonding hybridizations of the mirror and the NP-dimer which may offer a much stronger near-field enhancement than that of the isolated NP dimers over a broad wavelength range. Further, it is revealed that the huge near-field enhancement of these two modes exhibit different dependence on the NP-NP and NP-mirror hot spots, while both of their near-field resonance wavelengths can be tuned to the blue exponentially by increasing the NP-NP gaps or the NP-mirror separation. Our results here benifit significantly the fundamental understanding and practical applications of metallic NPs on a mirror in plasmonics.

  16. A rechargeable Na–CO 2 /O 2 battery enabled by stable nanoparticle hybrid electrolytes

    KAUST Repository

    Xu, Shaomao

    2014-09-10

    © the Partner Organisations 2014. We report on rechargeable batteries that use metallic sodium as the anode, a mixture of CO2 and O2 as the active material in the cathode, and an organic-inorganic hybrid liquid as electrolyte. The batteries are attractive among energy storage technologies because they provide a mechanism for simultaneously capturing CO2 emissions while generating electrical energy. Through in and ex situ chemical analysis of the cathode we show that NaHCO3 is the principal discharge product, and that its relative instability permits cell recharging. By means of differential electrochemical mass spectrometry (DEMS) based on 12C and 13C we further show that addition of as little as 10% of 1-methyl-3-propylimidazolium bis(trifluoromethanesulfone)imide ionic liquid tethered to SiO2 nanoparticles extends the high-voltage stability of the electrolyte by at least 1 V, allowing recharge of the Na-CO2/O2 cells. This journal is

  17. Hybridized plasmon modes and near-field enhancement of metallic nanoparticle-dimer on a mirror

    Science.gov (United States)

    Huang, Yu; Ma, Lingwei; Hou, Mengjing; Li, Jianghao; Xie, Zheng; Zhang, Zhengjun

    2016-01-01

    For the attractive plasmonic structure consisting of metal nanoparticles (NPs) on a mirror, the coexistence of near-field NP-NP and NP-mirror couplings is numerically studied at normal incidence. By mapping their 3D surface charge distributions directly, we have demonstrated two different kinds of mirror-induced bonding dipole plasmon modes and confirmed the bonding hybridizations of the mirror and the NP-dimer which may offer a much stronger near-field enhancement than that of the isolated NP dimers over a broad wavelength range. Further, it is revealed that the huge near-field enhancement of these two modes exhibit different dependence on the NP-NP and NP-mirror hot spots, while both of their near-field resonance wavelengths can be tuned to the blue exponentially by increasing the NP-NP gaps or the NP-mirror separation. Our results here benifit significantly the fundamental understanding and practical applications of metallic NPs on a mirror in plasmonics. PMID:27418039

  18. Synthesis of titanium oxide nanoparticles using DNA-complex as template for solution-processable hybrid dielectric composites

    Energy Technology Data Exchange (ETDEWEB)

    Ramos, J.C. [Center for Sustainable Materials Chemistry, 153 Gilbert Hall, Oregon State University, Corvallis, OR (United States); Mejia, I.; Murphy, J.; Quevedo, M. [Department of Materials Science and Engineering, University of Texas at Dallas, Dallas, TX (United States); Garcia, P.; Martinez, C.A. [Engineering and Technology Institute, Autonomous University of Ciudad Juarez, Ciudad Juarez, Chihuahua (Mexico)

    2015-09-15

    Highlights: • We developed a synthesis method to produce TiO{sub 2} nanoparticles using a DNA complex. • The nanoparticles were anatase phase (~6 nm diameter), and stable in alcohols. • Composites showed a k of 13.4, 4.6 times larger than the k of polycarbonate. • Maximum processing temperature was 90 °C. • Low temperature enables their use in low-voltage, low-cost, flexible electronics. - Abstract: We report the synthesis of TiO{sub 2} nanoparticles prepared by the hydrolysis of titanium isopropoxide (TTIP) in the presence of a DNA complex for solution processable dielectric composites. The nanoparticles were incorporated as fillers in polycarbonate at low concentrations (1.5, 5 and 7 wt%) to produce hybrid dielectric films with dielectric constant higher than thermally grown silicon oxide. It was found that the DNA complex plays an important role as capping agent in the formation and suspension stability of nanocrystalline anatase phase TiO{sub 2} at room temperature with uniform size (∼6 nm) and narrow distribution. The effective dielectric constant of spin-cast polycarbonate thin-films increased from 2.84 to 13.43 with the incorporation of TiO{sub 2} nanoparticles into the polymer host. These composites can be solution processed with a maximum temperature of 90 °C and could be potential candidates for its application in low-cost macro-electronics.

  19. Fabrication of hybrid nanocomposite scaffolds by incorporating ligand-free hydroxyapatite nanoparticles into biodegradable polymer scaffolds and release studies

    Directory of Open Access Journals (Sweden)

    Balazs Farkas

    2015-11-01

    Full Text Available We report on the optical fabrication approach of preparing free-standing composite thin films of hydroxyapatite (HA and biodegradable polymers by combining pulsed laser ablation in liquid and mask-projection excimer laser stereolithography (MPExSL. Ligand-free HA nanoparticles were prepared by ultrafast laser ablation of a HA target in a solvent, and then the nanoparticles were dispersed into the liquid polymer resin prior to the photocuring process using MPExSL. The resin is poly(propylene fumarate (PPF, a photo-polymerizable, biodegradable material. The polymer is blended with diethyl fumarate in 7:3 w/w to adjust the resin viscosity. The evaluation of the structural and mechanical properties of the fabricated hybrid thin film was performed by means of SEM and nanoindentation, respectively, while the chemical and degradation studies were conducted through thermogravimetric analysis, and FTIR. The photocuring efficiency was found to be dependent on the nanoparticle concentration. The MPExSL process yielded PPF thin films with a stable and homogenous dispersion of the embedded HA nanoparticles. Here, it was not possible to tune the stiffness and hardness of the scaffolds by varying the laser parameters, although this was observed for regular PPF scaffolds. Finally, the gradual release of the hydroxyapatite nanoparticles over thin film biodegradation is reported.

  20. Engineering of a novel adjuvant based on lipid-polymer hybrid nanoparticles: A quality-by-design approach.

    Science.gov (United States)

    Rose, Fabrice; Wern, Jeanette Erbo; Ingvarsson, Pall Thor; van de Weert, Marco; Andersen, Peter; Follmann, Frank; Foged, Camilla

    2015-07-28

    The purpose of this study was to design a novel and versatile adjuvant intended for mucosal vaccination based on biodegradable poly(DL-lactic-co-glycolic acid) (PLGA) nanoparticles (NPs) modified with the cationic surfactant dimethyldioctadecylammonium (DDA) bromide and the immunopotentiator trehalose-6,6'-dibehenate (TDB) (CAF01) to tailor humoral and cellular immunity characterized by antibodies and Th1/Th17 responses. Such responses are important for the protection against diseases caused by intracellular bacteria such as Chlamydia trachomatis and Mycobacterium tuberculosis. The hybrid NPs were engineered using an oil-in-water single emulsion method and a quality-by-design approach was adopted to define the optimal operating space (OOS). Four critical process parameters (CPPs) were identified, including the acetone concentration in the water phase, the stabilizer [polyvinylalcohol (PVA)] concentration, the lipid-to-total solid ratio, and the total concentration. The CPPs were linked to critical quality attributes consisting of the particle size, polydispersity index (PDI), zeta-potential, thermotropic phase behavior, yield and stability. A central composite face-centered design was performed followed by multiple linear regression analysis. The size, PDI, enthalpy of the phase transition and yield were successfully modeled, whereas the models for the zeta-potential and the stability were poor. Cryo-transmission electron microscopy revealed that the main structural effect on the nanoparticle architecture is caused by the use of PVA, and two different morphologies were identified: i) A PLGA core coated with one or several concentric lipid bilayers, and ii) a PLGA nanoshell encapsulating lipid membrane structures. The optimal formulation, identified from the OOS, was evaluated in vivo. The hybrid NPs induced antibody and Th1/Th17 immune responses that were similar in quality and magnitude to the response induced by DDA/TDB liposomes, showing that the adjuvant

  1. Hierarchical organization of Au nanoparticles in a poly(vinyl carbazole) matrix for hybrid electronic devices

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Sangkyu; Amarnath, Chellachamy A; Paik, Ungyu [Division of Advanced Materials Science Engineering, Hanyang University, Seoul 133-791 (Korea, Republic of); Yoon, Seon-Mi; Shin, Hyeon-Jin; Joo, Won-Jae; Choi, Jae-Young [Display Device and Processing Laboratory, Samsung Advanced Institute of Technology, Yongin-si 449-712 (Korea, Republic of); Yi, Dong Kee [Gachon Bionano Research Institute, Kyungwon University, Sungnam-si, 461-701 (Korea, Republic of)], E-mail: pandora@hanyang.ac.kr, E-mail: sm76.yoon@samsung.com, E-mail: hyeonjin.shin@samsung.com, E-mail: wj.joo@samsung.com, E-mail: vitalis@kyungwon.ac.kr, E-mail: jaeyoung88.choi@samsung.com, E-mail: ca_amar@yahoo.com, E-mail: upaik@hanyang.ac.kr

    2008-02-20

    We report a novel one-step method for the preparation of hierarchically patterned Au nanoparticles in a conducting polymer matrix by controlling the interface properties between Au nanoparticles and the conducting polymer matrix. The terminal group of capping molecules for the Au nanoparticles was modified to change the interface properties, not to change the size of the Au nanoparticles which affects their intrinsic properties. By modulating the interface properties, it is possible to construct Au nanoparticle-conducting polymer composites with two different structures: one presents a triple layer in which the conducting polymer layer is sandwiched between Au nanoparticle layers at the top and bottom; the other exhibits a form like a raisin cake in which Au nanoparticles are homogeneously organized in the conducting polymer matrix. High-resolution transmission electron microscopy was used to study the morphology and patterning of Au nanoparticles in the conducting polymer matrix.

  2. Hybrid composites made of multiwalled carbon nanotubes functionalized with Fe3O4 nanoparticles for tissue engineering applications

    Science.gov (United States)

    Cunha, C.; Panseri, S.; Iannazzo, D.; Piperno, A.; Pistone, A.; Fazio, M.; Russo, A.; Marcacci, M.; Galvagno, S.

    2012-11-01

    A straightforward technique for functionalization of multiwalled carbon nanotubes (MWCNTs) with magnetite (Fe3O4) nanoparticles was developed. Iron oxide nanoparticles were deposited on MWCNT surfaces by a deposition-precipitation method using Fe3+/Fe2+ salts precursors in basic solution. The characterizations by HRTEM, XRD, SEM/EDX, AAS and TPR analyses confirmed the successful formation of magnetic iron oxide nanoparticles on the MWCNT surface. Fe3O4/MWCNT hybrid composites were analysed in vitro by incubation with mesenchymal stem cells for 1, 3 and 7 days, either in the presence or absence of a static magnetic field. Analysis of cell proliferation was performed by the MTT assay, quantification of cellular stress was performed by the Lactate Dehydrogenase assay and analysis of cell morphology was performed by actin immunofluorescence and scanning electron microscopy. Results demonstrate that the introduction of magnetite into the MWCNT structure increases biocompatibility of oxidized MWCNTs. In addition, the presence of a static magnetic field further increases Fe3O4/MWCNT influence on cell behaviour. These results demonstrate this novel Fe3O4/MWCNT hybrid composite has good potential for tissue engineering applications.

  3. One-pot synthesis of hollow NiSe-CoSe nanoparticles with improved performance for hybrid supercapacitors

    Science.gov (United States)

    Chen, Haichao; Fan, Meiqiang; Li, Chao; Tian, Guanglei; Lv, Chunju; Chen, Da; Shu, Kangying; Jiang, Jianjun

    2016-10-01

    Hollow NiSe-CoSe samples have been synthesized for the first time via a one-pot solvothermal approach. The strategy is robust enough to synthesize NiSe-CoSe nanoparticles with different NiSe to CoSe ratios but with a similar hollow structure. Co ions in the NiSe-CoSe nanoparticles play decisive role for formation of the hollow structure; otherwise, the nanoparticles become solid for the NiSe sample. When used as the positive electroactive materials for energy storage, the NiSe-CoSe samples show excellent electrochemical activity in alkaline electrolyte. Using the synergistic effect between NiSe and CoSe, the electrochemical performance of NiSe-CoSe can be tuned by varying the NiSe to CoSe ratios. The NiSe-CoSe sample with a NiSe to CoSe ratio of 4:2 shows the best electrochemical performance in terms of superior specific capacity, improved rate capability and excellent cycling stability. In addition, the electrochemical performance of NiSe-CoSe sample with a NiSe to CoSe ratio of 4:2 is also evaluated via assembling hybrid supercapacitors with RGO, and the hybrid supercapacitor delivers both high power and energy densities (41.8 Wh kg-1 at 750 W kg-1 and 20.3 Wh kg-1 at 30 kW kg-1).

  4. Study of Antibacterial Efficacy of Hybrid Chitosan-Silver Nanoparticles for Prevention of Specific Biofilm and Water Purification

    Directory of Open Access Journals (Sweden)

    Somnath Ghosh

    2011-01-01

    Full Text Available Antibacterial efficacy of silver nanoparticles (Ag NPs deposited alternatively layer by layer (LBL on chitosan polymer in the form of a thin film over a quartz plate and stainless steel strip has been studied. An eight-bilayer chitosan/silver (Cs/Ag8 hybrid was prepared having a known concentration of silver. Techniques such as UV-visible spectroscopy, inductively coupled plasma optical emission spectroscopy (ICP-OES, and atomic force microscopy (AFM were carried out to understand and elucidate the physical nature of the film. Gram-negative bacteria, Escherichia coli (E. coli, were used as a test sample in saline solution for antibacterial studies. The growth inhibition at different intervals of contact time and, more importantly, the antibacterial properties of the hybrid film on repeated cycling in saline solution have been demonstrated. AFM studies are carried out for the first time on the microbe to know the morphological changes affected by the hybrid film. The hybrid films on aging (3 months are found to be as bioactive as before. Cytotoxicity experiments indicated good biocompatibility. The hybrid can be a promising bioactive material for the prevention of biofilms specific to E. coli and in purification of water for safe drinking.

  5. Highly flexible room temperature NO2 sensor based on WO3 nanoparticles loaded MWCNTs-RGO hybrid

    Science.gov (United States)

    Yaqoob, Usman; Chung, Gwiy-Sang

    2016-02-01

    Fabrication and characterizations of a flexible NO2 sensor based on tungsten trioxide nanoparticles-loaded multi-walled carbon nanotubes-reduced graphene oxide hybrid (WO3 NPs-loaded MWCNTs-RGO) on a polyimide/polyethylene terephthalate (PI/PET) substrate have been investigated. A viscous gel of the hybrid materials (WO3-MWCNTs-RGO) was prepared with the assistance of α-terpineol. To observe the physical and crystalline properties of hybrid materials FESEM, TEM and XRD was carried-out. Afterwards, sensor was fabricated by drop casting hybrid solution between two fingers gold (Au) electrodes. Finally, gas sensing properties were taken out in open air environment. The sensor showed excellent sensing performance towards NO2 including a maximum response of 17% (to 5 ppm), a limit of detection (LOD) of 1 ppm, and relatively short response/recovery time (7/15 min). The sensing behaviors of the fabricated flexible sensor were evaluated systematically at different curvature angles (0-90°) and after several times bending and relaxing (0-107). The sensor exhibited excellent mechanical flexibility and sensing properties at room temperature without any significant performance degradation even at a curvature angle of 90° and after 106 times bending and relaxing process. The results indicates that economical, light weight and mechanical robustness of the proposed WO3 NPs-MWCNTs- RGO hybrid based sensor can be a promising building block for the development of high performance flexible NO2 sensors.

  6. Gold nanoparticles modified with self-assembled hybrid monolayer of triblock aptamers as a photoreversible anticoagulant.

    Science.gov (United States)

    Huang, San-Shan; Wei, Shih-Chun; Chang, Huan-Tsung; Lin, Han-Jia; Huang, Chih-Ching

    2016-01-10

    We demonstrated that thrombin-binding aptamer-conjugated gold nanoparticles (TBA-Au NPs), prepared from a self-assembled hybrid monolayer (SAHM) of triblock aptamers on Au NPs (13 nm), can effectively inhibit thrombin activity toward fibrinogen. The first block poly(adenine) at the end of the triblock TBA was used for the self-assembly on Au NP surface. The second block, in the middle of TBA, was composed of oligonucleotides that could hybridize with each other. The third block, containing TBA15 (15-base, binding to the exosite I of thrombin) and TBA29 (29-base, binding to the exosite II of thrombin) provided bivalent interaction with thrombin. The SAHM triblock aptamers have optimal distances between TBA15 and TBA29, aptamer density, and orientation on the Au NP surfaces. These properties strengthen the interactions with thrombin (Kd=1.5 × 10(-11)M), resulting in an extremely high anticoagulant potency. The thrombin clotting time mediated by SAHM TBA15/TBA29-Au NPs was >10 times longer than that of four commercially available drugs (heparin, argatroban, hirudin, or warfarin). In addition, the rat-tail bleeding assay time further demonstrated that the SAHM TBA15/TBA29-Au NPs were superior to heparin. The SAHM TBA15/TBA29-Au NPs exhibited excellent stability in the human plasma (half-life >14 days) and good biocompatibility (low cytotoxicity and hemolysis). Most interestingly, the inhibition by SAHM TBA15/TBA29-Au NPs was controllable by the irradiation of green laser, via heat transfer-induced TBA release from Au NPs. Therefore, these easily prepared (self-assembled), low cost (non-thiolated aptamer), photo-controllable, multivalent TBA15/TBA29-Au NPs (high density of TBA15/TBA29 on Au NPs) show good potential for the treatment of various diseases related to blood-clotting disorders. Our study opens up the possibility of regulation of molecule binding, protein recognition, and enzyme activity using SAHM aptamer-functionalized nanomaterials. PMID:26643617

  7. Plasmonic Effect on the Population Dynamics and the Optical Response in a Hybrid V-Type Three-Level Quantum Dot-Metallic Nanoparticle Nanosystem

    CERN Document Server

    Ko, Myong-Chol; Choe, Song-Il; So, Gwang-Hyok; Kim, Pong-Ryol Jang Yong-Jin; Kim, Il-Gwang; Li, Jian-Bo

    2016-01-01

    We investigated theoretically the exciton-plasmon coupling effects on the population dynamics and the absorption properties of a hybrid nanosystem composed of a metal nanoparticle (MNP) and a V-type three level semiconductor quantum dot (SQD), which are created by the interaction with the induced dipole moments in the SQD and the MNP, respectively. Excitons of the SQD and the plasmons of the MNP in such a hybrid nanosystem could be coupled strongly or weakly to demonstrate novel properties of the hybrid system. Our results show that the nonlinear optical response of the hybrid nanosystem can be greatly enhanced or depressed due to the exciton-plasmon couplings.

  8. Pulmonary delivery of antitubercular drugs using spray-dried lipid-polymer hybrid nanoparticles.

    Science.gov (United States)

    Bhardwaj, Ankur; Mehta, Shuchi; Yadav, Shailendra; Singh, Sudheer K; Grobler, Anne; Goyal, Amit Kumar; Mehta, Abhinav

    2016-09-01

    The present study aimed to develop lipid-polymer hybrid nanoparticles (LPNs) for the combined pulmonary delivery of isoniazid (INH) and ciprofloxacin hydrochloride (CIP HCl). Drug-loaded LPNs were prepared by the double-emulsification solvent evaporation method using the three-factor three-level Box-Behnken design. The optimized formulation had a size of 111.81 ± 1.2 nm, PDI of 0.189 ± 1.4, and PDE of 63.64 ± 2.12% for INH-loaded LPN, and a size of 172.23 ± 2.31 nm, PDI of 0.169 ± 1.23, and PDE of 68.49 ± 2.54% for CIP HCl-loaded LPN. Drug release was found to be sustained and controlled at lower pH and followed the Peppas model. The in vitro uptake study in alveolar macrophage (AM) showed that uptake of the drugs was increased significantly if administered in the form of LPN. The stability study proved the applications of adding PLGA in LPN as the polymeric core, which leads to a much more stable product as compared to other novel drug delivery systems. Spray drying was done to produce an inhalable, dry, powdered form of drug-loaded LPN. The spray-dried (SD) powder was equally capable of producing nano-aggregates having morphology, density, flowability and reconstitutibility in the range ideal for inhaled drug delivery. The nano aggregates produced by spray drying manifested their aerosolization efficiency in terms of the higher emitted dose and fine particle fraction with lower mass median aerodynamic diameter. The in vivo study using pharmacokinetic and pharmacodynamic approaches revealed that maximum internalization efficiency was achieved by delivering LPN in SD powdered forms by pulmonary route. PMID:26178768

  9. Platinum porous nanoparticles hybrid with metal ions as probes for simultaneous detection of multiplex cancer biomarkers.

    Science.gov (United States)

    Wang, Zifeng; Liu, Na; Ma, Zhanfang

    2014-03-15

    In this work, platinum porous nanoparticles (PtPNPs) absorbed metal ions as electrochemical signals were fabricated. Clean-surface PtPNPs were prepared by a surfactant-free method and decorated with amino groups via 2-aminoethanethiol. Amino capped PtPNPs complexation with Cd(2+) and Cu(2+) to form PtPNPs-Cd(2+) and PtPNPs-Cu(2+) hybrids, respectively. Anti-CEA and Anti-AFP separately labeled with PtPNPs-Cd(2+) and PtPNPs-Cu(2+) were used as distinguishable signal tags for capturing antigens. The metal ions were detected in a single run through differential pulse voltammetry (DPV) without acid dissolution, electric potentials and peak heights of which reflected the identity and concentrations of the corresponding antigen. Ionic liquid reduced graphene oxide (IL-rGO) modified glassy carbon electrode (GCE) was used as a substrate, which was rich in amino groups to immobilize antibodies by glutaraldehyde through cross-link between aldehyde groups and amino groups. Using the proposed probes and platform, a novel sandwich-type electrochemical immunosensor for simultaneous detecting carcinoembryonic antigen (CEA) and alpha-fetoprotein (AFP) was successfully developed. This immunoassay possessed good linearity from 0.05 ng mL(-1) to 200 ng mL(-1) for both CEA and AFP. The detection limit of CEA was 0.002 ng mL(-1) and that of AFP was 0.05 ng mL(-1) (S/N=3). Furthermore, analysis of clinical serum samples using this immunosensor was well consistent with the data determined by the enzyme-linked immunosorbent assay (ELISA). It suggested that the proposed electrochemical immunoassay provided a potential application of clinical screening for early-stage cancers. PMID:24176967

  10. Synthesis and Characterization of Hybrid-Magnetic Nanoparticles and Their Application for Removal of Arsenic from Groundwater

    Directory of Open Access Journals (Sweden)

    Marta A. Bavio

    2013-01-01

    Full Text Available Multiwall carbon nanotubes (MWCNTs were oxidized with different agents and a characterization study was carried out. Then, hybrid-magnetic nanoparticles (HMNPs were synthesized as iron oxide supported on the selected multiwalled carbon nanotubes (MWCNTs-Fe3O4 obtained from MWCNTs oxidized with HNO3. The HMNPs characterization revealed the presence of iron oxide as magnetite onto the MWCNTs surfaces. These HMNPs were used for arsenic removal from groundwater. The adsorption process variables were optimized (concentration of NPs, contact time, and pH, and these systems could remove 39.93 mg As/g adsorbent. Therefore, these nanoparticles appear as a good alternative for removing arsenic from water samples.

  11. Degradation of Pollutant and Antibacterial Activity of Waterborne Polyurethane/Doped TiO2 Nanoparticle Hybrid Films

    Institute of Scientific and Technical Information of China (English)

    QIU Shan; DENG Fengxia; XU Shanwen; LIU Peng; MIN Xinmin; MA Fang

    2015-01-01

    The waterborne polyurethane/doped TiO2 nanoparticle hybrid films were prepared. Nd, I doped TiO2 was prepared with a 50 nm particle sizefi rstly. The hybridfi lm was prepared by mixing doped TiO2 with waterborne polyurethane, followed by heat treatment. The presence and nanometric distribution of doped TiO2 nanoparticles in prepared membranes is evident according to SEM images. The photocatalytic activities of doped TiO2 were signifi cantly enhanced compared with pure TiO2 powders. After the hybridfi lm fabrication, the photocatalytic activities were almost the same as the pure catalysts withkMB of 0.046. In the antibacterial testing, the hybridfi lms can inhibitE. coli growth. A signifi cant decrease in membranefl uidity and increase of permeability ofE. coli were observed.

  12. Efficiency Investigations of Organic/Inorganic Hybrid ZnO Nanoparticles Based Dye-Sensitized Solar Cells

    Directory of Open Access Journals (Sweden)

    Satbir Singh

    2016-01-01

    Full Text Available The present research study focuses upon the synthesis, characterization, and performances of optoelectronic properties of organic-inorganic (hybrid ZnO based dye sensitized solar cells. Initially, polymer dye A was synthesized using condensation reaction between 2-thiophenecarboxaldehyde and polyethylenimine and was capped to ZnO nanoparticles. Size and morphology of polymer dye A capped ZnO nanoparticles were analyzed using DLS, SEM, and XRD analysis. Further, the polymer dye was added to ruthenium metal complex (RuCl3 to form polymer-ruthenium composite dye B. Absorption and emission profiles of polymer dye A and polymer-ruthenium composite dye B capped ZnO nanoparticles were monitored using UV-Vis and fluorescence spectroscopy. Polymer dye A and polymer-ruthenium composite dye B capped ZnO nanoparticles were further processed to solar cells using wet precipitation method under room temperature. The results of investigations revealed that, after addition of ruthenium chloride (RuCl3 metal complex dye, the light harvesting capacity of ZnO solar cell was enhanced compared to polymer dye A capped ZnO based solar cell. The polymer-ruthenium composite dye B capped ZnO solar cell exhibited good photovoltaic performance with excellent cell parameters, that is, exciting open circuit voltage (Voc of 0.70 V, a short circuit current density (Jsc of 11.6 mA/cm2, and a fill factor (FF of 0.65. A maximum photovoltaic cell efficiency of 5.28% had been recorded under standard air mass (AM 1.5 simulated solar illuminations for polymer-ruthenium composite dye B based hybrid ZnO solar cell. The power conversion efficiency of hybrid ZnO based dye sensitized solar cell was enhanced by 1.78% and 3.88% compared to polymer dye A (concentrated and polymer dye A (diluted capped ZnO based dye sensitized solar cells, respectively. The hybrid organic/inorganic ZnO nanostructures can be implemented in a variety of optoelectronic applications in the future of clean and

  13. UCST-like hybrid PAAm-AA/Fe3O4 microgels. Effect of Fe3O4 nanoparticles on morphology, thermosensitivity and elasticity.

    Science.gov (United States)

    Echeverria, Coro; Mijangos, Carmen

    2011-07-01

    The incorporation of metal oxide nanoparticles into microgels forming hybrid systems gives additional functionalities to the system and widens the field of potential application in biomedicine, biotechnology, and other fields. In particular, there have been very few investigations regarding UCST-like hybrid microgels. In connection with this, we report the preparation of UCST-like hybrid microgels of magnetite nanoparticles (Fe(3)O(4)) encapsulated in poly(acrylamide-acrylic acid) microgel matrix via an inverse emulsion polymerization method. The key factor in the preparation of hybrid microgels is the need to divide in two the aqueous phase of the emulsion and feed them separately in order to avoid the aggregation of magnetic nanoparticles prior to polymerization reaction. The morphology, size, and spherical shape of hybrid microgels are determined by scanning electron microscopy. The encapsulation of magnetite nanoparticles within the polymer matrix is confirmed by transmission electron microscopy. Dynamic light scattering is employed to study both the swelling UCST-like behavior and the surface charge of the hybrid microgels. Swelling measurements confirm that the incorporation of magnetite does not affect the thermosensitivity of the system. In order to highlight the rheological behavior that can affect the final potential applications of these hybrid systems, a deep study of the viscoelastic properties is carried out by means of an oscillatory rheometer. The dependence of G' and G'' of the microgel dispersions with the frequency suggests a gel-like behavior and hence the occurrence of structural organization. In order to understand this structure formation and the influence of the magnetite in the interaction between hybrid microgels, scaling theory was applied. In terms of rheology, the addition of magnetite leads to a change in the interaction between hybrid microgels giving rise to an increase in the elasticity of the system.

  14. Performance of hybrid buffer Poly(3,4-ethylenedioxythiophene) poly(styrenesulfonate) layers doped with plasmonic silver nanoparticles

    Energy Technology Data Exchange (ETDEWEB)

    Kalfagiannis, N., E-mail: nkalf@physics.auth.gr [Laboratory for Thin Films-Nanosystems and Nanometrology (LTFN), Physics Department, Aristotle University of Thessaloniki, GR-54124 Thessaloniki (Greece); School of Science and Technology, Nottingham Trent University, NG11 8NS Nottingham (United Kingdom); Karagiannidis, P.G.; Pitsalidis, C. [Laboratory for Thin Films-Nanosystems and Nanometrology (LTFN), Physics Department, Aristotle University of Thessaloniki, GR-54124 Thessaloniki (Greece); Hastas, N. [Aristotle University of Thessaloniki, Physics Department, GR-54124 Thessaloniki (Greece); Panagiotopoulos, N.T.; Patsalas, P. [University of Ioannina, Department of Materials Science and Engineering, GR-45110 Ioannina (Greece); Logothetidis, S. [Laboratory for Thin Films-Nanosystems and Nanometrology (LTFN), Physics Department, Aristotle University of Thessaloniki, GR-54124 Thessaloniki (Greece)

    2014-06-02

    We compare the performance of a typical hole transport layer for organic photovoltaics (OPVs), Poly(3,4-ethylenedioxythiophene) poly(styrenesulfonate) (PEDOT:PSS) thin film with a series of PEDOT:PSS layers doped with silver (Ag) nanoparticles (NPs) of various size distributions. These hybrid layers have attracted great attention as buffer layers in plasmonic OPVs, although there is no report up to date on their isolated performance. In the present study we prepared a series of PEDOT:PSS layers sandwiched between indium tin oxide (ITO) and gold (Au) electrodes. Ag NPs were deposited on top of the ITO by electron beam evaporation followed by spin coating of PEDOT:PSS. Electrical characterization performed in the dark showed linear resistive behavior for all the samples; lower resistance was observed for the hybrid ones. It was found that the resistivity of the samples decreases with increasing the particle's size. A substantial increase of the electric field between the ITO and the Au electrodes was seen through the formation of current paths through the Ag NPs. A striking observation is the slight increase in the slope of the current density versus voltage curves when measured under illumination for the case of the plasmonic layers, indicating that changes in the electric field in the vicinity of the NP due to plasmonic excitation is a non-vanishing factor. - Highlights: • Maximized diffused scattering of light for the hybrid layers is observed. • Resistivity decreases as the particle size, for the hybrid layers, is increased. • Under illumination, plasmonic excitations affect the hybrid layer's performance. • These hybrid layers could provide lower series resistance to photovoltaic devices.

  15. Adsorption of environmental pollutants using magnetic hybrid nanoparticles modified with β-cyclodextrin

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Niejun [Key Lab of Organic Optoelectronic and Molecular Engineering, Department of Chemistry, Tsinghua University, Beijing 100084 (China); Beijing Key Laboratory of Microanalytical Method and Instrumentation, Department of Chemistry, Tsinghua University, Beijing, 100084 (China); Zhou, Lilin; Guo, Jun; Ye, Qiquan [Key Lab of Organic Optoelectronic and Molecular Engineering, Department of Chemistry, Tsinghua University, Beijing 100084 (China); Lin, Jin-Ming [Beijing Key Laboratory of Microanalytical Method and Instrumentation, Department of Chemistry, Tsinghua University, Beijing, 100084 (China); Yuan, Jinying, E-mail: yuanjy@mail.tsinghua.edu.cn [Key Lab of Organic Optoelectronic and Molecular Engineering, Department of Chemistry, Tsinghua University, Beijing 100084 (China)

    2014-06-01

    Graft through strategy was utilized to coat magnetic Fe{sub 3}O{sub 4} nanoparticles with poly(glycidyl methacrylate) using ordinary radical polymerization and then β-cyclodextrin was linked onto the surface of nanoparticles. With these nanoparticles modified with cyclodextrin groups, adsorption of two model environmental pollutants, bisphenol A and copper ions, was studied. Host–guest interactions between cyclodextrin and aromatic molecules had a great contribution to the adsorption of bisphenol A, while multiple hydroxyls of cyclodextrin also helped the adsorption of copper ions. These magnetic nanoparticles could be applied in the elimination, enrichment and detection of some environmental pollutants.

  16. Adsorption of environmental pollutants using magnetic hybrid nanoparticles modified with β-cyclodextrin

    Science.gov (United States)

    Wang, Niejun; Zhou, Lilin; Guo, Jun; Ye, Qiquan; Lin, Jin-Ming; Yuan, Jinying

    2014-06-01

    Graft through strategy was utilized to coat magnetic Fe3O4 nanoparticles with poly(glycidyl methacrylate) using ordinary radical polymerization and then β-cyclodextrin was linked onto the surface of nanoparticles. With these nanoparticles modified with cyclodextrin groups, adsorption of two model environmental pollutants, bisphenol A and copper ions, was studied. Host-guest interactions between cyclodextrin and aromatic molecules had a great contribution to the adsorption of bisphenol A, while multiple hydroxyls of cyclodextrin also helped the adsorption of copper ions. These magnetic nanoparticles could be applied in the elimination, enrichment and detection of some environmental pollutants.

  17. Oxaliplatin immuno hybrid nanoparticles for active targeting: an approach for enhanced apoptotic activity and drug delivery to colorectal tumors.

    Science.gov (United States)

    Tummala, Shashank; Gowthamarajan, K; Satish Kumar, M N; Wadhwani, Ashish

    2016-06-01

    Tumor necrosis factor related apoptosis inducing ligand (TRAIL) proved to be a promising new target for colorectal cancer treatment. Elevated expression of TRAIL protein in tumor cells distinguishes it from healthy cells, thereby delivering the drug at the specific site. Here, we formulated oxaliplatin immunohybrid nanoparticles (OIHNPs) to deliver oxaliplatin and anti-TRAIL for colorectal cancer treatment in xenograft tumor models. The polymeric chitosan layer binds to the lipid film with the mixture of phospholipids by an ultra sound method followed by conjugating with thiolated antibody using DSPE-PEG-mal3400, resulting in the formation of OIHNPs. The polymer layer helps in more encapsulation of the drug (71 ± 0.09%) with appreciable particle size (95 ± 0.01 nm), and lipid layer prevents degradation of the drug in serum by preventing nanoparticle aggregation. OIHNPs have shown a 4-fold decrease in the IC50 value compared to oxaliplatin in HT-29 cells by the MTT assay. These immuno-nanoparticles represent the successful uptake and internalization of oxaliplatin in HT-29 cells rather than in MCF-7 cells determined by triple fluorescence method. Apoptotic activity in vitro of OIHNPs was determined by the change in the mitochondria membrane potential that further elevates its anti-tumor property. Furthermore, the conjugated nanoparticles can effectively deliver the drug to the tumor sites, which can be attributed to its ability in reducing tumor mass and tumor volume in xenograft tumor models in vivo along with sustaining its release in vitro. These findings indicated that the oxaliplatin immuno-hybrid nanoparticles would be a promising nano-sized active targeted formulation for colorectal-tumor targeted therapy. PMID:26377238

  18. Half-Antibody Functionalized Lipid-Polymer Hybrid Nanoparticles for Targeted Drug Delivery to Carcinoembryonic Antigen (CEA) Presenting Pancreatic Cancer Cells

    Science.gov (United States)

    Hu, Che-Ming Jack; Kaushal, Sharmeela; Tran Cao, Hop S.; Aryal, Santosh; Sartor, Marta; Esener, Sadik; Bouvet, Michael; Zhang, Liangfang

    2010-01-01

    Current chemotherapy regimens against pancreatic cancer are met with little success as poor tumor vascularization significantly limits the delivery of oncological drugs. High-dose targeted drug delivery, through which a drug delivery vehicle releases a large payload upon tumor localization, is thus a promising alternative strategy against this lethal disease. Herein, we synthesize anti-CEA half-antibody conjugated lipid-polymer hybrid nanoparticles and characterize their ligand conjugation yields, physicochemical properties, and targeting ability against pancreatic cancer cells. Under the same drug loading, the half-antibody targeted nanoparticles show enhanced cancer killing effect compared to the corresponding non-targeted nanoparticles. PMID:20394436

  19. Controlled growth of silica-titania hybrid functional nanoparticles through a multistep microfluidic approach.

    Science.gov (United States)

    Shiba, K; Sugiyama, T; Takei, T; Yoshikawa, G

    2015-11-11

    Silica/titania-based functional nanoparticles were prepared through controlled nucleation of titania and subsequent encapsulation by silica through a multistep microfluidic approach, which was successfully applied to obtaining aminopropyl-functionalized silica/titania nanoparticles for a highly sensitive humidity sensor.

  20. Designing novel hybrid materials by one-pot co-condensation: from hydrophobic mesoporous silica nanoparticles to superamphiphobic cotton textiles.

    Science.gov (United States)

    Pereira, C; Alves, C; Monteiro, A; Magén, C; Pereira, A M; Ibarra, A; Ibarra, M R; Tavares, P B; Araújo, J P; Blanco, G; Pintado, J M; Carvalho, A P; Pires, J; Pereira, M F R; Freire, C

    2011-07-01

    This work reports the synthesis and characterization of mesoporous silica nanoparticles (MSNs) functionalized with tridecafluorooctyltriethoxysilane (F13) and their in situ incorporation onto cotton textiles. The hybrid MSNs and the functional textiles were prepared by a one-pot co-condensation methodology between tetraethylorthosilicate (TEOS) and F13, with hexadecyltrimethylammonium chloride (CTAC) as the template and triethanolamine as the base. The influence of the F13 to TEOS molar ratio (1:10, 1:5 and 1:3) on the nanoparticle morphology, porosity, degree of functionalization, and hydro/oleophobic properties is discussed. The hybrid nanosilicas presented high colloidal stability and were spherical and monodispersed with average particle size of ∼45 nm. They also showed high surface areas, large pore volumes, and a wormhole-type mesoporous structure. The increase in the organosilane proportion during the co-condensation process led to a more radially branched wormhole-like mesoporosity, a decrease in the surface area, pore volume, and amount of surface silanol groups, and an enrichment of the surface with fluorocarbon moieties. These changes imparted hydrophobic and oleophobic properties to the materials, especially to that containing the highest F13 loading. Cotton textiles were coated with the F13-MSNs through an efficient and less time-consuming route. The combination between surface roughness and mesoporosity imparted by the MSNs, and the low surface energy provided by the organosilane resulted in superhydrophobic functional textiles. Moreover, the textile with the highest loading of fluorocarbon groups was superamphiphobic. PMID:21615151

  1. Hybrid silica-gold core-shell nanoparticles for fluorescence enhancement

    Science.gov (United States)

    Grzelak, J.; Krajewska, A.; Krajnik, B.; Jamiola, D.; Choma, J.; Jankiewicz, B.; Piątkowski, D.; Nyga, P.; Mackowski, S.

    2016-06-01

    We demonstrate that SiO2 nanoparticles coated with a gold island film (GIF) provide an efficient plasmonic platform for enhancing fluorescence intensity of chlorophyll-containing photosynthetic complexes. Fluorescence images obtained for single SiO2-Au coreshell nanoparticles mixed with photosynthetic complexes reveal very uniform emission patterns of a circular shape, similarly as observed for bare SiO2 nanoparticles. The fluorescence enhancement of chlorophyll emission for SiO2-Au nanostructures is up to four-fold compared to bare SiO2 nanoparticles and shortening of fluorescence decay indicates its plasmonic origin. For doublets or triplets of core-shell SiO2-Au nanoparticles, the intensity of emission is further increased as a result of hot-spot formation at the interfaces of such assemblies.

  2. Preparation of composite PMMA microbeads hybridized with fluorescent YVO{sub 4}:Bi{sup 3+},Eu{sup 3+} nanoparticles

    Energy Technology Data Exchange (ETDEWEB)

    Akisada, K; Noguchi, Y; Isobe, T, E-mail: isobe@applc.keio.ac.jp [Department of Applied Chemistry, Faculty of Science and Technology, Keio University, 3-14-1 Hiyoshi, Kohoku-ku, Yokohama 223-8522 (Japan)

    2011-10-29

    Poly(methyl methacrylate) (PMMA) microbeads are hybridized with fluorescent YVO{sub 4}:Bi{sup 3+},Eu{sup 3+} nanoparticles using the layer-by-layer adsorption technique. The composite beads A are prepared by adsorbing negatively-charged YVO{sub 4}:Bi{sup 3+},Eu{sup 3+} nanoparticles onto positively-charged PMMA beads modified with poly(allylamine hydrochloride) (PAH). The composite beads B are prepared by adsorbing nanoparticles onto PMMA beads with multiple alternate layers of PAH and poly(sodium 4-styrenesulfonate) (PSS), i.e., with (PAH/PSS){sub 4}/PAH layers. The composite beads C are prepared by adsorbing 300 deg. C heated nanoparticles with negative charge onto PMMA beads with single PAH layer. These three kinds of composite beads are compared in terms of the amount of adsorbed nanoparticles and the fluorescent intensity.

  3. Multifunctional Peptide-Conjugated Hybrid Silica Nanoparticles for Photodynamic Therapy and MRI

    Directory of Open Access Journals (Sweden)

    Hamanou Benachour, Aymeric Sève, Thierry Bastogne, Céline Frochot, Régis Vanderesse, Jordane Jasniewski, Imen Miladi, Claire Billotey, Olivier Tillement, François Lux, Muriel Barberi-Heyob

    2012-01-01

    Full Text Available Photodynamic therapy (PDT is an emerging theranostic modality for various cancer as well as non-cancer diseases. Its efficiency is mainly based on a selective accumulation of PDT and imaging agents in tumor tissue. The vascular effect is widely accepted to play a major role in tumor eradication by PDT. To promote this vascular effect, we previously demonstrated the interest of using an active- targeting strategy targeting neuropilin-1 (NRP-1, mainly over-expressed by tumor angiogenic vessels. For an integrated vascular-targeted PDT with magnetic resonance imaging (MRI of cancer, we developed multifunctional gadolinium-based nanoparticles consisting of a surface-localized tumor vasculature targeting NRP-1 peptide and polysiloxane nanoparticles with gadolinium chelated by DOTA derivatives on the surface and a chlorin as photosensitizer. The nanoparticles were surface-functionalized with hydrophilic DOTA chelates and also used as a scaffold for the targeting peptide grafting. In vitro investigations demonstrated the ability of multifunctional nanoparticles to preserve the photophysical properties of the encapsulated photosensitizer and to confer photosensitivity to MDA-MB-231 cancer cells related to photosensitizer concentration and light dose. Using binding test, we revealed the ability of peptide-functionalized nanoparticles to target NRP-1 recombinant protein. Importantly, after intravenous injection of the multifunctional nanoparticles in rats bearing intracranial U87 glioblastoma, a positive MRI contrast enhancement was specifically observed in tumor tissue. Real-time MRI analysis revealed the ability of the targeting peptide to confer specific intratumoral retention of the multifunctional nanoparticles.

  4. Label-Free Dengue Detection Utilizing PNA/DNA Hybridization Based on the Aggregation Process of Unmodified Gold Nanoparticles

    Directory of Open Access Journals (Sweden)

    Samsulida Abdul Rahman

    2014-01-01

    Full Text Available A label-free optical detection method based on PNA/DNA hybridization using unmodified gold nanoparticles (AuNPs for dengue virus detection has been successfully developed. In this study, no immobilization method is involved and the hybridization of PNA/DNA occurs directly in solution. Unmodified AuNPs undergo immediate aggregation in the presence of neutral charge peptide nucleic acid (PNA due to the coating of PNA on AuNPs surface. However, in the presence of complementary targets DNA, the hybridization of PNA probe with target DNA forms negatively charged complexes due to the negatively charged phosphate backbone of the target DNA. The negatively charged complexes adsorbed onto the AuNPs surface ensure sufficient charge repulsion, need for AuNPs dispersion, and stability in solution. The detection procedure is a naked eye method based on immediate color changes and also through UV-vis adsorption spectra. The selectivity of the proposed method was studied successfully by single base mismatch and noncomplementary target DNA.

  5. Fluorescence energy transfer-based multiplexed hybridization assay using gold nanoparticles and quantum dot conjugates on photonic crystal beads

    International Nuclear Information System (INIS)

    A multiplexed assay strategy was developed for the detection of nucleic acid hybridization. It is based on fluorescence resonance energy transfer (FRET) between gold nanoparticles (AuNPs) and multi-sized quantum dots (QDs) deposited on the surface of silica photonic crystal beads (SPCBs). The SPCBs were first coated with a three-layer primer film formed by the alternating adsorption of poly(allylamine hydrochloride) and poly(sodium 4-styren sulfonate). Probe DNA sequences were then covalently attached to the carboxy groups at the surface of the QD-coated SPCBs. On addition of DNA-AuNPs and hybridization, the fluorescence of the donor QDs is quenched because of the close proximity of the AuNPs. However, the addition of target DNA causes a recovery of the fluorescence of the QD-coated SPCBs, thus enabling the quantitative assay of hybridized DNA. Compared to fluorescent dyes acting as acceptors, the use of AuNPs results in much higher quenching efficiency. The multiplexed assay displays a wide linear range, high sensitivity, and very little cross-reactivity. This work, where such SPCBs are used for the first time in a FRET assay, is deemed to present a new and viable approach towards high-throughput multiplexed gene assays. (author)

  6. Synthesis and characterization of magnetic cobalt ferrite nanoparticles covered with 3-aminopropyltriethoxysilane for use as hybrid material in nano technology

    International Nuclear Information System (INIS)

    Nowadays with the appear of nano science and nano technology, magnetic nanoparticles have been finding a variety of applications in the fields of biomedicine, diagnosis, molecular biology, biochemistry, catalysis, etc. The magnetic functionalized nanoparticles are constituted of a magnetic nucleus, involved by a polymeric layer with active sites, which ones could anchor metals or selective organic compounds. These nanoparticles are considered organic inorganic hybrid materials and have great interest as materials for commercial applications due to the specific properties. Among the important applications it can be mentioned: magneto hyperthermia treatment, drugs delivery in specific local of the body, molecular recognition, biosensors, enhancement of nuclear magnetic resonance images quality, etc. This work was developed in two parts: 1) the synthesis of the nucleus composed by superparamagnetic nanoparticles of cobalt ferrite and, 2) the recovering of nucleus by a polymeric bifunctional 3-aminopropyltriethoxysilane. The parameters studied in the first part of the research were: pH, hydroxide molar concentration, hydroxide type, reagent order of addition, reagent way of addition, speed of shake, metals initial concentrations, molar fraction of cobalt and thermal treatment. In the second part it was studied: pH, temperature, catalyst type, catalyst concentration, time of reaction, relation ratios of H2O/silane, type of medium and the efficiency of the recovering regarding to pH. The products obtained were characterized using the following techniques X-ray powder diffraction (DRX), transmission electronic microscopy (TEM), scanning electronic microscopy (SEM), spectroscopy of scatterbrained energy spectroscopy (DES), atomic emission spectroscopy (ICP-AES), thermogravimetric analysis (TGA/DTGA), Fourier transform infrared spectroscopy (FTIR), differential scanning calorimetry (DSC) and magnetization curves (VSM). (author)

  7. A ternary hybrid of carbon nanotubes/graphitic carbon nitride nanosheets/gold nanoparticles used as robust substrate electrodes in enzyme biofuel cells.

    Science.gov (United States)

    Gai, Panpan; Song, Rongbin; Zhu, Cheng; Ji, Yusheng; Chen, Yun; Zhang, Jian-Rong; Zhu, Jun-Jie

    2015-10-11

    A novel ternary hybrid of carbon nanotubes/graphitic carbon nitride nanosheets/gold nanoparticles was prepared and used as robust substrate electrodes for fabricating membrane-less glucose/O2 enzyme biofuel cells (EBFCs), and a remarkably improved power output was observed for the prepared EBFC.

  8. Poly(lactic acid)/chitosan hybrid nanoparticles for controlled release of anticancer drug.

    Science.gov (United States)

    Wang, Wenlong; Chen, Shu; Zhang, Liang; Wu, Xi; Wang, Jiexin; Chen, Jian-Feng; Le, Yuan

    2015-01-01

    Poly(lactic acid) (PLA) is a kind of non-toxic biological materials with excellent absorbability, biocompatibility and biodegradability, which can be used for drug release, tissue engineering and surgical treatment applications. In this study, we prepared chitosan modified PLA nanoparticles as carriers for encapsulation of docetaxel by anti-solvent precipitation method. The morphology, particle size, zeta potential and composition of the PLA/chitosan were characterized by SEM, DLS, FTIR and XPS. As-prepared PLA/chitosan particles exhibited average size of 250 nm and showed very narrow distribution with polydispersity index of 0.098. Their large surface charge-ability was confirmed by zeta potential value of 53.9 mV. Docetaxel was released from PLA/chitosan nanoparticles with 40% initial burst release in 5 h and 70% cumulative release within 24 h, while from PLA nanoparticles 65% of docetaxel was released in 5h. In vitro drug release study demonstrated that PLA/chitosan nanoparticles prolonged drug release and decreased the burst release over the unmodified PLA nanoparticles. These results illustrated high potential of chitosan modified PLA nanoparticles for usage as anticancer drug carriers. PMID:25492016

  9. Poly(lactic acid)/chitosan hybrid nanoparticles for controlled release of anticancer drug.

    Science.gov (United States)

    Wang, Wenlong; Chen, Shu; Zhang, Liang; Wu, Xi; Wang, Jiexin; Chen, Jian-Feng; Le, Yuan

    2015-01-01

    Poly(lactic acid) (PLA) is a kind of non-toxic biological materials with excellent absorbability, biocompatibility and biodegradability, which can be used for drug release, tissue engineering and surgical treatment applications. In this study, we prepared chitosan modified PLA nanoparticles as carriers for encapsulation of docetaxel by anti-solvent precipitation method. The morphology, particle size, zeta potential and composition of the PLA/chitosan were characterized by SEM, DLS, FTIR and XPS. As-prepared PLA/chitosan particles exhibited average size of 250 nm and showed very narrow distribution with polydispersity index of 0.098. Their large surface charge-ability was confirmed by zeta potential value of 53.9 mV. Docetaxel was released from PLA/chitosan nanoparticles with 40% initial burst release in 5 h and 70% cumulative release within 24 h, while from PLA nanoparticles 65% of docetaxel was released in 5h. In vitro drug release study demonstrated that PLA/chitosan nanoparticles prolonged drug release and decreased the burst release over the unmodified PLA nanoparticles. These results illustrated high potential of chitosan modified PLA nanoparticles for usage as anticancer drug carriers.

  10. Magnetic and optical properties of Ag@SiO{sub 2}-FITC-Fe{sub 3}O{sub 4} hybrid nanoparticles

    Energy Technology Data Exchange (ETDEWEB)

    Sui, Ning [Université de Lyon, Institut des Nanotechnologies de Lyon–INL, UMR CNRS 5270, Site Ecole Centrale de Lyon, 36 Avenue Guy de Collongue, F-69134 Ecully Cedex (France); College of Material Science and Engineering, Qingdao University of Science and Technology, Qingdao 266042 (China); Monnier, Virginie, E-mail: virginie.monnier@ec-lyon.fr [Université de Lyon, Institut des Nanotechnologies de Lyon–INL, UMR CNRS 5270, Site Ecole Centrale de Lyon, 36 Avenue Guy de Collongue, F-69134 Ecully Cedex (France); Salvia, Marie-Virginie; Chevolot, Yann; Souteyrand, Eliane [Université de Lyon, Institut des Nanotechnologies de Lyon–INL, UMR CNRS 5270, Site Ecole Centrale de Lyon, 36 Avenue Guy de Collongue, F-69134 Ecully Cedex (France)

    2014-03-15

    Highlights: • New magnetic/fluorescent nanoparticles were synthesized. • The silver core led to a maximum 4-fold enhanced fluorescence of fluorophore. • Maximum enhancement factor was obtained when metal-fluorophore distance is 5 nm. • Magnetism and fluorescence appeared simultaneously for nanoparticles in solution. -- Abstract: Nanoparticles composed of a silver core coated with a silica shell (Ag@SiO{sub 2}) were prepared. A dye, fluorescein isothiocyanate (FITC), was further encapsulated during the growth of a second silica shell onto Ag@SiO{sub 2} nanoparticles. The proximity of silver nanoparticles led to a 4-fold maximal enhancement in the fluorescence of FITC when the first silica shell thickness was set at 5 nm. After amino-functionalization of Ag@SiO{sub 2}-FITC nanoparticles, iron oxide nanoparticles were bonded to their surface. The magnetic and metal-enhanced fluorescence properties appeared simultaneously when Ag@SiO{sub 2}-FITC-Fe{sub 3}O{sub 4} hybrid nanoparticles were dispersed in a solution.

  11. Coexistence of superparamagnetism and optical activity in Ni{sub x}Pt{sub 1-x}/CdSe hybrid nanoparticles

    Energy Technology Data Exchange (ETDEWEB)

    Albrecht, Ole; Menke, Torben; Nielsch, Kornelius; Goerlitz, Detlef [Institut fuer Angewandte Physik und Zentrum fuer Mikrostrukturforschung, Universitaet Hamburg, Jungiusstrasse 11, 20355 Hamburg (Germany); Niehaus, Jan; Ahrenstorf, Kirsten; Weller, Horst [Institut fuer Physikalische Chemie, Universitaet Hamburg, Grindelallee 117, 20146 Hamburg (Germany)

    2008-07-01

    NiPt-nanoparticles, the synthesis of which have been described previously together with their magnetical properties, where used as starting point for the synthesis of new complex hybrid nanoparticles. Covering Ni{sub x}Pt{sub 1-x}-particles with CdSe, an optically active semiconductor, a core-shell hybrid particle is formed featuring magnetic and, moreover, optical properties: the particles luminesce between 680 nm and 695 nm, detected by ensemble photoluminescence spectroscopy. The pure Ni{sub x}Pt{sub 1-x}-particles exhibit a superparamagnetic behavior with a blocking temperature T{sub b}{approx}4 K shown by SQUID-magnetometry. In the hybrid particles, T{sub b} is shifted to lower temperatures. Possible reasons for this are discussed.

  12. Generation of Localized Surface Plasmon Resonance Using Hybrid Au–Ag Nanoparticle Arrays as a Sensor of Polychlorinated Biphenyls Detection

    Directory of Open Access Journals (Sweden)

    Jing Liu

    2016-08-01

    Full Text Available In this study, the hybrid Au–Ag hexagonal lattice of triangular and square lattice of quadrate periodic nanoparticle arrays (PNAs were designed to investigate their extinction spectra of the localized surface plasmon resonances (LSPRs. First, their simulating extinction spectra were calculated by discrete dipole approximation (DDA numerical method by changing the media refractive index. Simulation results showed that as the media refractive index was changed from 1.0 to 1.2, the maximum peak intensity of LSPRs spectra had no apparent change and the wavelength to reveal the maximum peak intensity of LSPRs spectra was shifted lower value. Polystyrene (PS nanospheres with two differently arranged structures were used as the templates to deposit the hybrid Au–Ag hexagonal lattice of triangular and square lattice of quadrate periodic PNAs by evaporation method. The hybrid Au–Ag hexagonal lattice of triangular and square lattice of quadrate PNAs were grown on single crystal silicon (c-Si substrates, and their measured extinction spectra were compared with the calculated results. Finally, the fabricated hexagonal lattices of triangular PNAs were investigated as a sensor of polychlorinated biphenyl solution (PCB-77 by observing the wavelength to reveal the maximum extinction efficiency (λmax. We show that the adhesion of β-cyclodextrins (SH-β-CD on the hybrid Au–Ag hexagonal lattice of triangular PNAs could be used to increase the variation of λmax. We also demonstrate that the adhesion of SH-β-CD increases the sensitivity and detection effect of PCB-77 in hexagonal lattice of triangular PNAs.

  13. Room temperature synthesis of an optically and thermally responsive hybrid PNIPAM-gold nanoparticle

    Energy Technology Data Exchange (ETDEWEB)

    Morones, J. Ruben, E-mail: morones@bu.ed [Boston University, Department of Biomedical Engineering (United States); Frey, Wolfgang, E-mail: wfrey@mail.utexas.ed [University of Texas at Austin, Department of Biomedical Engineering (United States)

    2010-05-15

    Composites of metal nanoparticles and environmentally sensitive polymers are useful as nanoactuators that can be triggered externally using light of a particular wavelength. We demonstrate a synthesis route that is easier than grafting techniques and allows for the in situ formation of individual gold nanoparticles encapsulated by an environmentally sensitive polymer, while also providing a strong interaction between the polymer and the metal particle. We present a one-pot, room-temperature synthesis route for gold metal nanoparticles that uses poly-N-isopropyl acrylamide as the capping and stabilizing agent and ascorbic acid as the reducing agent and achieves size control similar to the most common citric acid synthesis. We show that the composite can be precipitated reversibly by temperature or light using the non-radiative decay and conversion to heat of the surface plasmon resonance of the metal nanoparticle. The precipitation is induced by the collapse of the polymer cocoon surrounding each gold nanoparticle, as can be seen by surface plasmon spectroscopy. The experiments agree with theoretical models for the heat generation in a colloidal suspension that support fast switching with low laser power densities. The synthesized composite is a simple nanosized opto-thermal switch.

  14. Modelling the size and polydispersity of magnetic hybrid nanoparticles for luminescent sensing of oxygen

    International Nuclear Information System (INIS)

    We report on a strategy to model both the size (d) and the polydispersity (PdI) of magnetic oxygen-sensitive nanoparticles with a typical size of 200 nm in order to increase the surface area. The strategy is based on experimental design and Response Surface Methodology. Nanoparticles were prepared by mini emulsion solvent evaporation of solutions of poly(styrene-co-maleic anhydride). Features of this strategy include (1) a quick selection of the most important variables that govern d and PdI; (2) a better understanding of the parameters that affect the performance of the polymer; and (3) optimized conditions for the synthesis of nanoparticles of targeted d and PdI. The results were used to produce nanoparticles in sizes that range from 100 to 300 nm and with small polydispersity. The addition of a platinum porphyrin complex that acts as a luminescent probe for oxygen and of magnetite (Fe3O4) to the polymeric particles, did not affect d and PdI, thus demonstrating that this strategy simplifies their synthesis. The resulting luminescent and magnetic sensor nanoparticles respond to dissolved oxygen with sensitivity (Stern-Volmer constant) of around 35 bar−1. (author)

  15. Ag nanoparticle-ZnO nanowire hybrid nanostructures as enhanced and robust antimicrobial textiles via a green chemical approach

    Science.gov (United States)

    Li, Zhou; Tang, Haoying; Yuan, Weiwei; Song, Wei; Niu, Yongshan; Yan, Ling; Yu, Min; Dai, Ming; Feng, Siyu; Wang, Menghang; Liu, Tengjiao; Jiang, Peng; Fan, Yubo; Wang, Zhong Lin

    2014-04-01

    A new approach for fabrication of a long-term and recoverable antimicrobial nanostructure/textile hybrid without increasing the antimicrobial resistance is demonstrated. Using in situ synthesized Ag nanoparticles (NPs) anchored on ZnO nanowires (NWs) grown on textiles by a ‘dip-in and light-irradiation’ green chemical method, we obtained ZnONW@AgNP nanocomposites with small-size and uniform Ag NPs, which have shown superior performance for antibacterial applications. These new Ag/ZnO/textile antimicrobial composites can be used for wound dressings and medical textiles for topical and prophylactic antibacterial treatments, point-of-use water treatment to improve the cleanliness of water and antimicrobial air filters to prevent bioaerosols accumulating in ventilation, heating, and air-conditioning systems.

  16. Sensitive DNA-hybridization biosensors based on gold nanoparticles for testing DNA damage by Cd(II) ions

    International Nuclear Information System (INIS)

    A DNA biosensor was constructed by immobilizing a 20-mer oligonucleotide probe and hybridizing it with its complementary oligomer on the surface of a glassy carbon electrode modified with gold nanoparticles. The properties of the biosensor and its capability of recognizing its complementary sequence were studied by electrochemical impedance spectroscopy. The oxidative stress caused by cadmium ions can be monitored by differential pulse voltammetry using the cobalt(III)tris(1,10-phenanthroline) complex and methylene blue as electrochemical indicators. The biosensor is capable of indicating damage caused by Cd(II) ions in pH 6.0 solution. The results showed that the biosensor can be used for rapid screening for DNA damage. (author)

  17. Discovery and in Vivo Evaluation of Novel RGD-Modified Lipid-Polymer Hybrid Nanoparticles for Targeted Drug Delivery

    Directory of Open Access Journals (Sweden)

    Yinbo Zhao

    2014-09-01

    Full Text Available In the current study, the lipid-shell and polymer-core hybrid nanoparticles (lpNPs modified by Arg–Gly–Asp(RGD peptide, loaded with curcumin (Cur, were developed by emulsification-solvent volatilization method. The RGD-modified hybrid nanoparticles (RGD–lpNPs could overcome the poor water solubility of Cur to meet the requirement of intravenous administration and tumor active targeting. The obtained optimal RGD-lpNPs, composed of PLGA (poly(lactic-co-glycolic acid–mPEG (methoxyl poly(ethylene- glycol, RGD–polyethylene glycol (PEG–cholesterol (Chol copolymers and lipids, had good entrapment efficiency, submicron size and negatively neutral surface charge. The core-shell structure of RGD–lpNPs was verified by TEM. Cytotoxicity analysis demonstrated that the RGD–lpNPs encapsulated Cur retained potent anti-tumor effects. Flow cytometry analysis revealed the cellular uptake of Cur encapsulated in the RGD–lpNPs was increased for human umbilical vein endothelial cells (HUVEC. Furthermore, Cur loaded RGD–lpNPs were more effective in inhibiting tumor growth in a subcutaneous B16 melanoma tumor model. The results of immunofluorescent and immunohistochemical studies by Cur loaded RGD–lpNPs therapies indicated that more apoptotic cells, fewer microvessels, and fewer proliferation-positive cells were observed. In conclusion, RGD–lpNPs encapsulating Cur were developed with enhanced anti-tumor activity in melanoma, and Cur loaded RGD–lpNPs represent an excellent tumor targeted formulation of Cur which might be an attractive candidate for cancer therapy.

  18. Composit, Nanoparticle-Based Anode material for Li-ion Batteries Applied in Hybrid Electric (HEV's)

    Energy Technology Data Exchange (ETDEWEB)

    Dr. Malgorzata Gulbinska

    2009-08-24

    Lithium-ion batteries are promising energy storage devices in hybrid and electric vehicles with high specific energy values ({approx}150 Wh/kg), energy density ({approx}400 Wh/L), and long cycle life (>15 years). However, applications in hybrid and electric vehicles require increased energy density and improved low-temperature (<-10 C) performance. Silicon-based anodes are inexpensive, environmentally benign, and offer excellent theoretical capacity values ({approx}4000 mAh/g), leading to significantly less anode material and thus increasing the overall energy density value for the complete battery (>500 Wh/L). However, tremendous volume changes occur during cycling of pure silicon-based anodes. The expansion and contraction of these silicon particles causes them to fracture and lose electrical contact to the current collector ultimately severely limiting their cycle life. In Phase I of this project Yardney Technical Products, Inc. proposed development of a carbon/nano-silicon composite anode material with improved energy density and silicon's cycleability. In the carbon/nano-Si composite, silicon nanoparticles were embedded in a partially-graphitized carbonaceous matrix. The cycle life of anode material would be extended by decreasing the average particle size of active material (silicon) and by encapsulation of silicon nanoparticles in a ductile carbonaceous matrix. Decreasing the average particle size to a nano-region would also shorten Li-ion diffusion path and thus improve rate capability of the silicon-based anodes. Improved chemical inertness towards PC-based, low-temperature electrolytes was expected as an additional benefit of a thin, partially graphitized coating around the active electrode material.

  19. Fluorescence quenching method for the determination of catechol with gold nanoparticles and tyrosinase hybrid system

    Institute of Scientific and Technical Information of China (English)

    Martin; M.F.Choi

    2010-01-01

    The determination method of catechol by fluorescence quenching was developed.The assay was based on the combination of the unique property of gold nanoparticles with tyrosinase enzymatic reaction.In the presence of tyrosinase,the fluorescence of gold nanoparticles was quenched by catechol which can be employed to detect catechol.Under the optimal conditions,a linear range 5.0×10~(-7)-1.0×10~(-3) mol L~(-1) and a detection limit 1.0×10~(-7) mol L~(-1) of catechol were obtained.o-Quinone intermediate produ...

  20. Improved Efficiency of Silicon Nanoholes/Gold Nanoparticles/Organic Hybrid Solar Cells via Localized Surface Plasmon Resonance

    Science.gov (United States)

    Lu, Ronghua; Xu, Ling; Ge, Zhaoyun; Li, Rui; Xu, Jun; Yu, Linwei; Chen, Kunji

    2016-03-01

    Silicon is the most widely used material for solar cells due to its abundance, non-toxicity, reliability, and mature fabrication process. In this paper, we fabricated silicon nanoholes (SiNHS)/gold nanoparticles (AuNPS)/organic hybrid solar cells and investigated their spectral and opto-electron conversion properties. SiNHS nanocomposite films were fabricated by metal-assisted electroless etching (EE) method. Then, we modified the surface of the nanocomposite films by exposing the samples in the air. After that, polymer poly(3,4-ethylenedioxythiophene):poly (styrenesulfonate) (PEDOT:PSS) blended with AuNPS were spin-coated on the surface of the SiNHS nanocomposite films as a hole-transporting layer. The external quantum efficiency (EQE) values of the solar cells with AuNPS are higher than that of the samples without AuNPS in the spectral region of 600-1000 nm, which were essential to achieve high performance photovoltaic cells. The power conversion efficiency (PCE) of the solar cells incorporating AuNPS exhibited an enhancement of 27 %, compared with that of the solar cells without AuNPS. We thought that the improved efficiency were attributed to localized surface plasmon resonance (LSPR) triggered by gold nanoparticles in SiNHS nanocomposite films.

  1. Spectroscopic Investigation of the Canopy Configurations in Nanoparticle Organic Hybrid Materials of Various Grafting Densities during CO 2 Capture

    KAUST Repository

    Petit, Camille

    2012-01-12

    Novel liquid-like nanoparticle organic hybrid materials (NOHMs) made of polyetheramine chains tethered onto functionalized silica nanoparticles were synthesized and characterized before and after exposure to CO 2 using NMR, Raman, and ATR FT-IR spectroscopies in order to investigate the effect of the grafting densities on the NOHM canopy structure. Considering the promising tunable properties for CO 2 capture of NOHMs, this study was conducted to provide important structural information to better design NOHMs for CO 2 capture. In order to minimize the CO 2 absorption via enthalpic effect and provide a more accurate assessment of the structural effects, the NOHMs were synthesized without task-specific groups. A greater chain ordering and decreased intermolecular interactions were observed in NOHMs compared to the unbound polymer. This was attributed to the specific structural arrangement of the frustrated canopy. The distinct configuration of grafted polymer chains caused different CO 2 packing and CO 2-induced swelling behaviors between the NOHMs and the unbound polymer. The grafting density influenced the ordering and coupling of the polymer chains and CO 2-induced swelling. Its effect on the CO 2 packing behavior was less pronounced. © 2011 American Chemical Society.

  2. Investigation of CO2 capture mechanisms of liquid-like nanoparticle organic hybrid materials via structural characterization

    KAUST Repository

    Park, Youngjune

    2011-01-01

    Nanoparticle organic hybrid materials (NOHMs) have been recently developed that comprise an oligomeric or polymeric canopy tethered to surface-modified nanoparticles via ionic or covalent bonds. It has already been shown that the tunable nature of the grafted polymeric canopy allows for enhanced CO 2 capture capacity and selectivity via the enthalpic intermolecular interactions between CO2 and the task-specific functional groups, such as amines. Interestingly, for the same amount of CO2 loading NOHMs have also exhibited significantly different swelling behavior compared to that of the corresponding polymers, indicating a potential structural effect during CO2 capture. If the frustrated canopy species favor spontaneous ordering due to steric and/or entropic effects, the inorganic cores of NOHMs could be organized into unusual structural arrangements. Likewise, the introduction of small gaseous molecules such as CO2 could reduce the free energy of the frustrated canopy. This entropic effect, the result of unique structural nature, could allow NOHMs to capture CO2 more effectively. In order to isolate the entropic effect, NOHMs were synthesized without the task-specific functional groups. The relationship between their structural conformation and the underlying mechanisms for the CO2 absorption behavior were investigated by employing NMR and ATR FT-IR spectroscopies. The results provide fundamental information needed for evaluating and developing novel liquid-like CO2 capture materials and give useful insights for designing and synthesizing NOHMs for more effective CO2 capture. © the Owner Societies 2011.

  3. Ultrasensitive electrochemical sensor for Hg(2+) by using hybridization chain reaction coupled with Ag@Au core-shell nanoparticles.

    Science.gov (United States)

    Li, Zongbing; Miao, Xiangmin; Xing, Ke; Peng, Xue; Zhu, Aihua; Ling, Liansheng

    2016-06-15

    A novel electrochemical biosensor for Hg(2+) detection was reported by using DNA-based hybridization chain reaction (HCR) coupled with positively charged Ag@Au core-shell nanoparticles ((+)Ag@Au CSNPs) amplification. To construct the sensor, capture probe (CP ) was firstly immobilized onto the surface of glass carbon electrode (GCE). In the presence of Hg(2+), the sandwiched complex can be formed between the immobilized CP on the electrode surface and the detection probe (DP) modified on the gold nanoparticles (AuNPs) based on T-Hg(2+)-T coordination chemistry. The carried DP then opened two ferrocene (Fc) modified hairpin DNA (H1 and H2) in sequence and propagated the happen of HCR to form a nicked double-helix. Numerous Fc molecules were formed on the neighboring probe and produced an obvious electrochemical signal. Moreover, (+)Ag@Au CSNPs were assembly onto such dsDNA polymers as electrochemical signal enhancer. Under optimal conditions, such sensor presents good electrochemical responses for Hg(2+) detection with a detection limit of 3.6 pM. Importantly, the methodology has high selectivity for Hg(2+) detection. PMID:26852203

  4. Enzymatically Degradable Hybrid Organic-Inorganic Bridged Silsesquioxane Nanoparticles for In-Vitro Imaging

    KAUST Repository

    Fatieiev, Yevhen

    2015-06-30

    Non-aggregated dense bridged silsesquioxane (BS) nanoparticles based on nature-inspired oxamide bridges are shown to degrade in simulated biological media upon cleavage with endopeptidase. Fluorescent BS nanoprobes with incorporated fluorescein dyes were applied for in-vitro imaging in cancer cells.

  5. Silica nanoparticle-based dual imaging colloidal hybrids: cancer cell imaging and biodistribution

    Directory of Open Access Journals (Sweden)

    Lee H

    2015-08-01

    Full Text Available Haisung Lee,1 Dongkyung Sung,2 Jinhoon Kim,3 Byung-Tae Kim,3 Tuntun Wang,4 Seong Soo A An,5 Soo-Won Seo,6 Dong Kee Yi4 1Molecular Diagnostics, In Vitro Diagnostics Unit, New Business Division, SK Telecom, 2Department of Life Sciences, Graduate School of Korea University, 3Interdisciplinary Graduate Program of Biomedical Engineering, School of Medicine, Sungkyunkwan University, Samsung Medical Center, 4Department of Chemistry, Myongji University, Seoul, 5Department of Bionanotechnology, Gachon Medical Research Institute, Gachon University, Seongnam, 6Medical Device Development Center, Daegu-Gyeongbuk Medical Innovation Foundation, Daegu, Republic of Korea Abstract: In this study, fluorescent dye-conjugated magnetic resonance (MR imaging agents were investigated in T mode. Gadolinium-conjugated silica nanoparticles were successfully synthesized for both MR imaging and fluorescence diagnostics. Polyamine and polycarboxyl functional groups were modified chemically on the surface of the silica nanoparticles for efficient conjugation of gadolinium ions. The derived gadolinium-conjugated silica nanoparticles were investigated by zeta potential analysis, transmission electron microscopy, inductively coupled plasma mass spectrometry, and energy dispersive x-ray spectroscopy. MR equipment was used to investigate their use as contrast-enhancing agents in T1 mode under a 9.4 T magnetic field. In addition, we tracked the distribution of the gadolinium-conjugated nanoparticles in both lung cancer cells and organs in mice. Keywords: dual bioimaging, MR imaging, silica colloid, T1 contrast imaging, nanohybrid

  6. Molecular-like Redox Activity and Size-dependent Electrocatalysis of Inorganic Hybrid Nanoparticles

    DEFF Research Database (Denmark)

    Chi, Qijin; Zhu, Nan; Ulstrup, Jens

    The development of low-cost, robust and high-efficient nanoscale electrocatalysts is arguably a dream approach to the use of nanomaterials as key building blocks in design and construction of chemical and biological sensing devices as well as fuel cells. Electroactive nanoparticles are a type of ...

  7. PVDF membranes containing hybrid nanoparticles for adsorbing cationic dyes: physical insights and mechanism

    Science.gov (United States)

    Sharma, Maya; Madras, Giridhar; Bose, Suryasarathi

    2016-07-01

    In this study, Fe (iron) and Ag (silver) based adsorbents were synthesized using solution combustion and in situ reduction techniques. The synthesized adsorbents were comprehensively characterized by different techniques including electron microscopy, BET, XRD, Zeta potential etc. Three chlorinated cationic dyes used were malachite green, methyl violet and pyronin Y. These dyes were adsorbed on various synthesized adsorbents [iron III oxide (Fe2O3)], iron III oxide decorated silver nanoparticles by combustion synthesis technique [Fe2O3–Ag(C)] and iron III oxide decorated silver nanoparticles using in situ reduction, [Fe2O3–Ag (S)]. The isotherm and the adsorption kinetics have been studied systematically. The kinetic data can be explained by the pseudo second order model and the adsorption equilibrium followed Langmuir isotherm. The equilibrium and kinetics results suggest that Fe2O3–Ag(S) nanoparticles showed the maximum adsorption among all the adsorbents. Hence, Polyvinylidene fluoride based membranes containing Fe2O3–Ag(S) nanoparticles were prepared via phase inversion (precipitation immersion using DMF/water) technique. The adsorption kinetics were studied in detail and it was observed that the composite membrane showed synergistic improvement in dye adsorption. Such membranes can be used for water purification.

  8. PEO-b-P4VP/Yttrium Hydroxide Hybrid Nanotubes as Supporter for Catalyst Gold Nanoparticles

    Institute of Scientific and Technical Information of China (English)

    Qian Yang; Dao-yong Chen

    2012-01-01

    The adsorption of poly (ethylene oxide)-b-poly(4-vinylpyridine)(PEO-b-P4VP) micelles onto the surface of yttrium hydroxide nanotubes (YNTs) resulted in the hybrid nanotubes with a dense P4VP inner layer and a stretched PEO outer layer surrounding YNTs. The dense P4VP layer was further stabilized by the crosslinking using 1,4-dibromobutane as the crosslinker.Then,the crosslinked hybrid nanotubes (CHNTs) were used as a novel nano supporter for loading the catalyst gold nanoparticles (GNPs) within the crosslinkcd P4VP layer.The resultant GNPs/CHNTs (GNTs loaded on CHNTs) were applied to catalyze the reduction reaction of p-nitrophenol.The results indicate that this novel nano supporter has advantages such as good dispersity in the suspension,high capacity in loading GNPs (0.87 mmol/g),high catalytic activity of the loaded GNPs (12.9 μmol-1min-1),and good reusability of GNTs/CHNTs.

  9. Electrogenerated Chemiluminescence Behavior of Au nanoparticles-hybridized Pb (II) metal-organic framework and its application in selective sensing hexavalent chromium

    OpenAIRE

    Hongmin Ma; Xiaojian Li; Tao Yan; Yan Li; Haiyang Liu; Yong Zhang; Dan Wu; Bin Du; Qin Wei

    2016-01-01

    In this work, a novel electrochemiluminescence (ECL) sensor based on Au nanoparticles-hybridized Pb (II)-β-cyclodextrin (Pb-β-CD) metal-organic framework for detecting hexavalent chromium (Cr(VI)) was developed. Pb-β-CD shows excellent ECL behavior and unexpected reducing ability towards Au ions. Au nanoparticles could massively form on the surface of Pb-β-CD (Au@Pb-β-CD) without use of any additional reducing agent. In the presence of coreactant K2S2O8, the ECL emission of Pb-β-CD was enhanc...

  10. Revealing the synergetic effects in Ni nanoparticle-carbon nanotube hybrids by scanning transmission X-ray microscopy and their application in the hydrolysis of ammonia borane

    Science.gov (United States)

    Zhao, Guanqi; Zhong, Jun; Wang, Jian; Sham, Tsun-Kong; Sun, Xuhui; Lee, Shuit-Tong

    2015-05-01

    The hybrids of carbon nanotubes (CNTs) and the supported Ni nanoparticles (NPs) have been studied by scanning transmission X-ray microscopy (STXM) and tested by the hydrolysis reaction of ammonia borane (AB, NH3BH3). Data clearly showed the existence of a strong interaction between Ni NPs and thin CNTs (C-O-Ni bonds), which favored the tunable (buffer) electronic structure of Ni NPs facilitating the catalytic process. The hydrolysis process of AB confirmed the hypothesis that the hybrids with a strong interfacial interaction would show superior catalytic performance, while the hybrids with a weak interfacial interaction show poor performance. Our results provide a wealth of detailed information regarding the electronic structure of the NP-CNT hybrids and provide guidance towards the rational design of high-performance catalysts for energy applications.The hybrids of carbon nanotubes (CNTs) and the supported Ni nanoparticles (NPs) have been studied by scanning transmission X-ray microscopy (STXM) and tested by the hydrolysis reaction of ammonia borane (AB, NH3BH3). Data clearly showed the existence of a strong interaction between Ni NPs and thin CNTs (C-O-Ni bonds), which favored the tunable (buffer) electronic structure of Ni NPs facilitating the catalytic process. The hydrolysis process of AB confirmed the hypothesis that the hybrids with a strong interfacial interaction would show superior catalytic performance, while the hybrids with a weak interfacial interaction show poor performance. Our results provide a wealth of detailed information regarding the electronic structure of the NP-CNT hybrids and provide guidance towards the rational design of high-performance catalysts for energy applications. Electronic supplementary information (ESI) available: Magnified TEM images, high resolution TEM images and the particle size distributions of the samples, the STXM results of a thick tube at different positions, XPS results, stability test. See DOI: 10.1039/c5nr01168j

  11. Exploiting energy transfer in hybrid metal and semiconductor nanoparticle systems for biosensing and energy harvesting

    Energy Technology Data Exchange (ETDEWEB)

    Mayilo, Sergiy

    2009-06-19

    In this work, gold and semiconductor nanoparticles are used as building blocks for nanostructures, in which energy transfer is investigated. Fluorescence quenching by gold nanoparticles is investigated and used to develop novel immunoassays for medically relevant molecules. The influence of gold nanoparticles on radiative and non-radiative rates of Cy3 and Cy3B dyes is studied here. A competitive, homogeneous immunoassay for digoxigenin and digoxin, a drug used to cure heart diseases, is developed. The assay has a limit of detection of 0.5 nM in buffer and 50 nM in serum. Time resolved spectroscopy reveals that the quenching is due to energy transfer with an efficiency of 70%. A homogeneous sandwich immunoassay for cardiac troponin T, an indicator of damage to the heart muscle, is developed. Gold nanoparticles and fluorophores are functionalized with anti-troponin T antibodies. In the presence of troponin T the nanoparticles and fluorophores form a sandwich structure, in which the dye fluorescence is quenched by a gold nanoparticle. The limit of detection of the immunoassay in buffer is 0.02 nM and 0.11 nM in serum. Energy transfer is demonstrated in clusters of CdTe nanocrystals assembled using three methods. In the first method, clusters of differently-sized water soluble CdTe nanocrystals capped by negatively charged mercaptoacid stabilizers are produced through electrostatic interactions with positively charged Ca{sup 2+} cations. The two other methods employ covalent binding through dithiols and thiolated DNA as linkers between nanocrystals. Energy transfer from smaller nanocrystals to larger nanocrystals in aggregates is demonstrated by means of steady-state and time-resolved photoluminescence spectroscopy, paving the way for nanocrystal-based light harvesting structures in solution. Multi-shell onion-like CdSe/ZnS/CdSe/ZnS nanocrystals are presented. The shade of the white light can be controlled by annealing the particles. Evidence for intra

  12. Dispersion of Iron Nanoparticles by Polymer-Based Hybrid Material for Reduction of Hexavalent Chromium

    Directory of Open Access Journals (Sweden)

    Syed Wasim Ali

    2015-01-01

    Full Text Available A gel type acrylic acid resin, based on ethyl acrylate-co-1,7-octadiene, has been synthesized by suspension polymerization at 20% cross-linking and subsequent hydrolysis by H2SO4. Capacity of the resin was observed to be 8.90 meq/g or 3.28 meq/mL. The iron nanoparticles used in this study were synthesized by ferrous sulphate method by using LiBH4 as a reductant and characterized by SEM, TEM, XRD, surface area, and electrical properties. Later, the resin was applied for the dispersion of iron nanoparticles over its surface for the reduction of Cr(VI and subsequent adsorption of Fe(III and Cr(III as byproducts. In the column studies the reduction of Cr(VI and the adsorption of Cr(III and Fe(III have been observed up to 240 μmole/L.

  13. Hybrid Hydroxyapatite Nanoparticle Colloidal Gels are Injectable Fillers for Bone Tissue Engineering

    OpenAIRE

    Wang, Qun; Gu, Zhen; Jamal, Syed; Detamore, Michael S.; Berkland, Cory

    2013-01-01

    Injectable bone fillers have emerged as an alternative to the invasive surgery often required to treat bone defects. Current bone fillers may benefit from improvements in dynamic properties such as shear thinning during injection and recovery of material stiffness after placement. Negatively charged inorganic hydroxyapatite (HAp) nanoparticles (NPs) were assembled with positively charged organic poly(d,l-lactic-co-glycolic acid) (PLGA) NPs to create a cohesive colloidal gel. This material is ...

  14. Electronic Tongue Based on Nanostructured Hybrid Films of Gold Nanoparticles and Phthalocyanines for Milk Analysis

    Directory of Open Access Journals (Sweden)

    Luiza A. Mercante

    2015-01-01

    Full Text Available The use of gold nanoparticles combined with other organic and inorganic materials for designing nanostructured films has demonstrated their versatility for various applications, including optoelectronic devices and chemical sensors. In this study, we reported the synthesis and characterization of gold nanoparticles stabilized with poly(allylamine hydrochloride (Au@PAH NPs, as well as the capability of this material to form multilayer Layer-by-Layer (LbL nanostructured films with metal tetrasulfonated phthalocyanines (MTsPc. Film growth was monitored by UV-Vis absorption spectroscopy, atomic force microscopy (AFM, and Fourier transform infrared spectroscopy (FTIR. Once LbL films have been applied as active layers in chemical sensors, Au@PAH/MTsPc and PAH/MTsPc LbL films were used in an electronic tongue system for milk analysis regarding fat content. The capacitance data were treated using Principal Component Analysis (PCA, revealing the role played by the gold nanoparticles on the LbL films electrical properties, enabling this kind of system to be used for analyzing complex matrices such as milk without any prior pretreatment.

  15. Synthesis and luminescent properties of PEO/lanthanide oxide nanoparticle hybrid films

    International Nuclear Information System (INIS)

    In this study, we investigate the optical properties of lanthanide oxide nanoparticles dispersed in poly(ethylene oxide) (PEO) network as thermally stable polymeric films. The aim of this work is both to keep a good optical transparency in the visible domain and to obtain luminescent materials after incorporation of nanoparticles. For this purpose, we develop luminescent nanocrystals of oxides containing terbium ion as a doping element in Gd2O3. These sub-5-nm lanthanide oxides nanoparticles have been prepared by direct oxide precipitation in high-boiling polyalcohol solutions and characterized by luminescence spectroscopy. PEO/lanthanide oxide nanohybrid films are prepared by radical polymerization of poly(ethylene glycol) methacrylate after introduction of lanthanide oxide particles. As a first result; the obtained films present interesting luminescence properties with a very low lanthanide oxide content (up to 0.29 wt%). Furthermore, these films are still transparent and keep their original mechanical properties. Prior to describe the specific applications to optical use, we report here the dynamic mechanical analysis (DMA), X-ray diffraction (XRD) analysis, transmission electron microscopy (TEM), and luminescent properties of. nanohybrid films

  16. Effects of ceria nanoparticle concentrations on the morphology and corrosion resistance of cerium–silane hybrid coatings on electro-galvanized steel substrates

    Energy Technology Data Exchange (ETDEWEB)

    Zandi Zand, Roohangiz [Department of Analytical Chemistry, Ghent University, Krijgslaan 281-S12, B-9000 Ghent (Belgium); Verbeken, Kim [Department of Materials Science and Engineering, Ghent University, Technologiepark 903, Zwijnaarde, B-9052 Ghent (Belgium); Flexer, Victoria [Department of Analytical Chemistry, Ghent University, Krijgslaan 281-S12, B-9000 Ghent (Belgium); Adriaens, Annemie, E-mail: annemie.adriaens@ugent.be [Department of Analytical Chemistry, Ghent University, Krijgslaan 281-S12, B-9000 Ghent (Belgium)

    2014-06-01

    This work investigates the effect of the ceria nanoparticle concentration on the morphology and electrochemical behavior of cerium–silane hybrid coatings deposited on electro-galvanized steel substrates. The substrates were pre-treated with 3-glycidoxypropyl-trimethoxysilane and bisphenol A, modified with cerium ion-activated CeO{sub 2} nanoparticles. The morphology of the coating before and after corrosion tests was examined using atomic force microscopy and scanning electron microscopy. The results indicate the formation of nanostructured surfaces with relatively uniform thicknesses and nanoparticle distribution. Microscopic observations explain the increased durability of the silane coating doped with the lowest content of activated ceria nanoparticles after short-term corrosion tests (456 h). The corrosion behavior of the sol–gel coatings was also investigated using natural salt spray tests, electrochemical impedance spectroscopy, and potentiodynamic polarization tests. The results show that the concentration of nanoparticles has a significant impact on the barrier properties of the silane films, which are improved for films with lower nanoparticle contents. - Graphical abstract: Display Omitted - Highlights: • We investigate the effect of ceria content on corrosion resistance of silane coating. • Microscopic images explain longer durability of the coating contain the lowest ceria. • The EIS results confirm the lower ceria content results in better barrier properties.

  17. Silsesquioxane-based hybrid nanocomposites with methacrylate units containing titania and/or silver nanoparticles as antibacterial/antifungal coatings for monumental stones

    Energy Technology Data Exchange (ETDEWEB)

    Aflori, Magdalena [“Petru Poni” Institute of Macromolecular Chemistry, 41A Grigore Ghica Voda Alley, 700487 Iasi (Romania); Simionescu, Bogdana [“Petru Poni” Institute of Macromolecular Chemistry, 41A Grigore Ghica Voda Alley, 700487 Iasi (Romania); “Costin D. Nenitescu” Centre of Organic Chemistry, 202B Splaiul Independentei, 7114 Bucharest (Romania); Bordianu, Irina-Elena; Sacarescu, Liviu; Varganici, Cristian-Dragos; Doroftei, Florica; Nicolescu, Alina [“Petru Poni” Institute of Macromolecular Chemistry, 41A Grigore Ghica Voda Alley, 700487 Iasi (Romania); Olaru, Mihaela, E-mail: olaruma@icmpp.ro [“Petru Poni” Institute of Macromolecular Chemistry, 41A Grigore Ghica Voda Alley, 700487 Iasi (Romania)

    2013-11-20

    Highlights: • Synthesis of nanocomposites with noble metals having high antibacterial efficiency. • Silver nanoparticles antibacterial activity for monumental stone conservation. • A high antibacterial activity while assuring good stone protection. -- Abstract: The present paper reports on the evaluation of two silsesquioxane-based hybrid nanocomposites with methacrylate units containing titania and/or silver nanoparticles aimed as antibacterial coatings for monumental stones. Sol–gel reaction of titanium isopropoxide and/or 3-(trimethoxysilyl)propyl methacrylate, in the presence of silver nitrate and a primary amine surfactant, yielded new types of hybrid nanocomposites with high antibacterial/antifungal efficacy. Different polymer behaviours regarding a frequently used monumental stone originating from Romania were evidenced through Fourier-transform infrared (FTIR) spectroscopy and powder X-ray diffraction (PXRD) technique. Conclusions regarding the stones acid-resistant character and lower influence of salt weathering on its durability, as well as a better protective coating containing titania units were revealed.

  18. Silsesquioxane-based hybrid nanocomposites with methacrylate units containing titania and/or silver nanoparticles as antibacterial/antifungal coatings for monumental stones

    International Nuclear Information System (INIS)

    Highlights: • Synthesis of nanocomposites with noble metals having high antibacterial efficiency. • Silver nanoparticles antibacterial activity for monumental stone conservation. • A high antibacterial activity while assuring good stone protection. -- Abstract: The present paper reports on the evaluation of two silsesquioxane-based hybrid nanocomposites with methacrylate units containing titania and/or silver nanoparticles aimed as antibacterial coatings for monumental stones. Sol–gel reaction of titanium isopropoxide and/or 3-(trimethoxysilyl)propyl methacrylate, in the presence of silver nitrate and a primary amine surfactant, yielded new types of hybrid nanocomposites with high antibacterial/antifungal efficacy. Different polymer behaviours regarding a frequently used monumental stone originating from Romania were evidenced through Fourier-transform infrared (FTIR) spectroscopy and powder X-ray diffraction (PXRD) technique. Conclusions regarding the stones acid-resistant character and lower influence of salt weathering on its durability, as well as a better protective coating containing titania units were revealed

  19. Dynamic control of the location of nanoparticles in hybrid co-assemblies

    Science.gov (United States)

    Su, Zhilong; Li, Xiaokang; Jiang, Xuesong; Lin, Shaoliang; Yin, Jie

    2015-03-01

    We herein demonstrated an approach to control the spatial distribution of components in hybrid microspheres. Hybrid core-shell structured microspheres (CSMs) prepared through co-assembly were used as starting materials, which are comprised of anthracene-ended hyperbranched poly(ether amine) (AN-hPEA) in the shell and crystallized anthracene containing polyhedral oligomer silsesquioxane (AN-POSS). Upon thermal annealing at a temperature higher than the melting point of AN-POSS, the diffusion of AN-POSS from the core to the shell of CSM leads to a transition of morphology from the core-shell structure to core-transition-shell to the more stable homogeneous morphology, which has been revealed by experimental results of TEM and DSC. The mechanism for the morphology transition of CSM induced by the diffusion of AN-POSS was disclosed by a dissipative particle dynamics (DPD) simulation. A mathematical model for the diffusion of POSS in the hybrid microsphere is established according to Fick's law of diffusion and can be used to quantify its distribution in CSM. Thus, the spatial distribution of POSS in the microsphere can be controlled dynamically by tuning the temperature and time of thermal annealing.We herein demonstrated an approach to control the spatial distribution of components in hybrid microspheres. Hybrid core-shell structured microspheres (CSMs) prepared through co-assembly were used as starting materials, which are comprised of anthracene-ended hyperbranched poly(ether amine) (AN-hPEA) in the shell and crystallized anthracene containing polyhedral oligomer silsesquioxane (AN-POSS). Upon thermal annealing at a temperature higher than the melting point of AN-POSS, the diffusion of AN-POSS from the core to the shell of CSM leads to a transition of morphology from the core-shell structure to core-transition-shell to the more stable homogeneous morphology, which has been revealed by experimental results of TEM and DSC. The mechanism for the morphology transition

  20. Cobalt nanoparticle-embedded carbon nanotube/porous carbon hybrid derived from MOF-encapsulated Co3O4 for oxygen electrocatalysis.

    Science.gov (United States)

    Dou, Shuo; Li, Xingyue; Tao, Li; Huo, Jia; Wang, Shuangyin

    2016-08-11

    We successfully obtained a novel bi-functional electrocatalyst towards the ORR and OER: Co nanoparticle-embedded N-doped carbon nanotube (CNT)/porous carbon (PC) by pyrolyzing metal organic framework (MOF) encapsulated Co3O4. The as-obtained hybrid exhibited highly efficient electrocatalytic activity for the ORR and OER. Furthermore, the assembled Zn-air batteries also revealed promising performance and long-term stability. PMID:27411845

  1. CaMoO{sub 4}:Tb-Fe{sub 3}O{sub 4} hybrid nanoparticles for luminescence and hyperthermia applications

    Energy Technology Data Exchange (ETDEWEB)

    Parchur, A. K.; Rai, S. B. [Department of Physics, Banaras Hindu University, Varanasi-221 005 (India); Kaurav, N. [Department of Physics, Government Holkar Science College, Indore-452 001 (India); Ansari, A. A. [King Abdullah Institute for Nanotechnology, King Saud University, Riyadh-11451 (Saudi Arabia); Prasad, A. I.; Ningthoujam, R. S. [Chemistry Division, Bhabha Atomic Research Centre, Mumbai-400 085 (India)

    2013-02-05

    We have prepared CaMoO{sub 4}:Tb-Fe{sub 3}O{sub 4} hybrid nanoparticles by co-precipitation and polyol method. Their temperature kinetics for hyperthermia temperature {approx}43 Degree-Sign C under different applied AC fields and the luminescence properties under UV-radiation are investigated. A strong green emission is observed due to the presence of Tb{sup 3+} ions.

  2. Synthesis and mechanical behavior of carbon nanotube-magnesium composites hybridized with nanoparticles of alumina

    International Nuclear Information System (INIS)

    Carbon nanotubes reinforced magnesium based composites were prepared with diligence and care using the powder metallurgy route coupled with rapid microwave sintering. Nanometer-sized particles of alumina were used to hybridize the carbon nanotubes reinforcement in the magnesium matrix so as to establish the intrinsic influence of hybridization on mechanical behavior of the resultant composite material. The yield strength, tensile strength and strain-to-failure of the carbon nanotubes-magnesium composites were found to increase with the addition of nanometer-sized alumina particles to the composite matrix. Scanning electron microscopy observations of the fracture surfaces of the samples deformed and failed in uniaxial tension revealed the presence of cleavage-like features on the fracture surface indicative of the occurrence of locally brittle fracture mechanism in the composite microstructure

  3. Synthetic Polymer Hybridization with DNA and RNA Directs Nanoparticle Loading, Silencing Delivery, and Aptamer Function

    OpenAIRE

    Zhou, Zhun; Xia, Xin; Bong, Dennis

    2015-01-01

    We report herein discrete triplex hybridization of DNA and RNA with polyacrylates. Length-monodisperse triazine-derivatized polymers were prepared on gram-scale by reversible addition–fragmentation chain-transfer polymerization. Despite stereoregio backbone heterogeneity, the triazine polymers bind T/U-rich DNA or RNA with nanomolar affinity upon mixing in a 1:1 ratio, as judged by thermal melts, circular dichroism, gel-shift assays, and fluorescence quenching. We call these polyacrylates “bi...

  4. Hybrid Antifouling and Antimicrobial Coatings Prepared by Electroless Co-Deposition of Fluoropolymer and Cationic Silica Nanoparticles on Stainless Steel: Efficacy against Listeria monocytogenes.

    Science.gov (United States)

    Huang, Kang; Chen, Juhong; Nugen, Sam R; Goddard, Julie M

    2016-06-29

    Controlling formation, establishment, and proliferation of microbial biofilms on surfaces is critical for ensuring public safety. Herein, we report on the synthesis of antimicrobial nanoparticles and their co-deposition along with fluorinated nanoparticles during electroless nickel plating of stainless steel. Plating bath composition is optimized to ensure sufficiently low surface energy to resist fouling and microbial adhesion as well as to exert significant (>99.99% reduction) antimicrobial activity against Listeria monocytogenes. The resulting coatings present hybrid antifouling and antimicrobial character, can be applied onto stainless steel, and do not rely on leaching or migration of the antimicrobial nanoparticles to be effective. Such coatings can support reducing public health issues related to microbial cross-contamination in areas such as food processing, hospitals, and water purification. PMID:27268033

  5. Facile Preparation of TiO2 Nanobranch/Nanoparticle Hybrid Architecture with Enhanced Light Harvesting Properties for Dye-Sensitized Solar Cells

    Directory of Open Access Journals (Sweden)

    Ju Seong Kim

    2015-01-01

    Full Text Available We report TiO2 nanobranches/nanoparticles (NBN hybrid architectures that can be synthesized by a facile solution phase method. The hybrid architecture simultaneously improves light harvesting and charge collection performances for a dye-sensitized solar cell. First, TiO2 nanorods with a trunk length of 2 μm were grown on a fluorine-doped tin oxide (FTO/glass substrate, and then nanobranches and nanoparticles were deposited on the nanorods’ trunks through a solution method using an aqueous TiCl3 solution at 80°C. The relative amount of nanobranches and nanoparticles can be controlled by multiplying the number of TiCl3 treatments to maximize the amount of surface area. We found that the resultant TiO2 NBN hybrid architecture greatly improves the amount of dye adsorption (five times compared to bare nanorods due to the enhanced surface area, while maintaining a fast charge collection, leading to a three times higher current density and thus tripling the maximum power conversion efficiency for a dye-sensitized solar cell.

  6. Preparation of Core-Shell Hybrid Materials by Producing a Protein Corona Around Magnetic Nanoparticles

    Science.gov (United States)

    Weidner, A.; Gräfe, C.; von der Lühe, M.; Remmer, H.; Clement, J. H.; Eberbeck, D.; Ludwig, F.; Müller, R.; Schacher, F. H.; Dutz, S.

    2015-07-01

    Nanoparticles experience increasing interest for a variety of medical and pharmaceutical applications. When exposing nanomaterials, e.g., magnetic iron oxide nanoparticles (MNP), to human blood, a protein corona consisting of various components is formed immediately. The composition of the corona as well as its amount bound to the particle surface is dependent on different factors, e.g., particle size and surface charge. The actual composition of the formed protein corona might be of major importance for cellular uptake of magnetic nanoparticles. The aim of the present study was to analyze the formation of the protein corona during in vitro serum incubation in dependency of incubation time and temperature. For this, MNP with different shells were incubated in fetal calf serum (FCS, serving as protein source) within a water bath for a defined time and at a defined temperature. Before and after incubation the particles were characterized by a variety of methods. It was found that immediately (seconds) after contact of MNP and FCS, a protein corona is formed on the surface of MNP. This formation led to an increase of particle size and a slight agglomeration of the particles, which was relatively constant during the first minutes of incubation. A longer incubation (from hours to days) resulted in a stronger agglomeration of the FCS incubated MNP. Quantitative analysis (gel electrophoresis) of serum-incubated particles revealed a relatively constant amount of bound proteins during the first minutes of serum incubation. After a longer incubation (>20 min), a considerably higher amount of surface proteins was determined for incubation temperatures below 40 °C. For incubation temperatures above 50 °C, the influence of time was less significant which might be attributed to denaturation of proteins during incubation. Overall, analysis of the molecular weight distribution of proteins found in the corona revealed a clear influence of incubation time and temperature on corona

  7. Preparation of Core-Shell Hybrid Materials by Producing a Protein Corona Around Magnetic Nanoparticles.

    Science.gov (United States)

    Weidner, A; Gräfe, C; von der Lühe, M; Remmer, H; Clement, J H; Eberbeck, D; Ludwig, F; Müller, R; Schacher, F H; Dutz, S

    2015-12-01

    Nanoparticles experience increasing interest for a variety of medical and pharmaceutical applications. When exposing nanomaterials, e.g., magnetic iron oxide nanoparticles (MNP), to human blood, a protein corona consisting of various components is formed immediately. The composition of the corona as well as its amount bound to the particle surface is dependent on different factors, e.g., particle size and surface charge. The actual composition of the formed protein corona might be of major importance for cellular uptake of magnetic nanoparticles. The aim of the present study was to analyze the formation of the protein corona during in vitro serum incubation in dependency of incubation time and temperature. For this, MNP with different shells were incubated in fetal calf serum (FCS, serving as protein source) within a water bath for a defined time and at a defined temperature. Before and after incubation the particles were characterized by a variety of methods. It was found that immediately (seconds) after contact of MNP and FCS, a protein corona is formed on the surface of MNP. This formation led to an increase of particle size and a slight agglomeration of the particles, which was relatively constant during the first minutes of incubation. A longer incubation (from hours to days) resulted in a stronger agglomeration of the FCS incubated MNP. Quantitative analysis (gel electrophoresis) of serum-incubated particles revealed a relatively constant amount of bound proteins during the first minutes of serum incubation. After a longer incubation (>20 min), a considerably higher amount of surface proteins was determined for incubation temperatures below 40 °C. For incubation temperatures above 50 °C, the influence of time was less significant which might be attributed to denaturation of proteins during incubation. Overall, analysis of the molecular weight distribution of proteins found in the corona revealed a clear influence of incubation time and temperature on

  8. One-pot synthesis of hybrid multifunctional silica nanoparticles with tunable coating by click chemistry in reverse w/o microemulsion.

    Science.gov (United States)

    Tissandier, Cédric; Diop, Noël; Martini, Matteo; Roux, Stéphane; Tillement, Olivier; Hamaide, Thierry

    2012-01-10

    Multifunctional hybrid silica nanoparticles with a fluorescent core and tunable organic or polymeric shell can easily be prepared by a sol-gel process followed by 1,3 dipolar cycloaddition (CuAAC) in the same reverse quaternary W/O microemulsion. Compared to a classical multistep process, this one-pot synthesis reduces greatly the number of purification steps and avoids aggregation phenomena. The confinement of reactants inside the micellar system gives rise to a noticeable increase of the CuAAC reaction rate. In addition, using simultaneously two different substrates for CuAAC on silica allows us to obtain directly multifunctional hybrid nanoparticles displaying a double grafting without any separation or purification steps except the final recovery by centrifugation, which opens the door to a tunable coating of the nanoparticles. Particularly, the hydrophilic-lipophilic balance of the coating can be adjusted by implementing the pertinent MPEG:dodecyl azide ratio. As an application, the great versatility of this strategy has been proved by the one-pot synthesis of fluorescent silica nanoparticles with a PEG coating and encapsulating silver clusters. PMID:22066823

  9. Self-assembled block copolymer-nanoparticle hybrids: interplay between enthalpy and entropy.

    Science.gov (United States)

    Sarkar, Biswajit; Alexandridis, Paschalis

    2012-11-13

    The dispersion of nanoparticles in ordered block copolymer nanostructures can provide control over particle location and orientation, and pave the way for engineered nanomaterials that have enhanced mechanical, electrical, or optical properties. Fundamental questions pertaining to the role of enthalpic and entropic particle-polymer interactions remain open and motivate the present work. We consider here a system of 10.6 nm silica nanoparticles (NPs) dispersed in ordered cylinders formed by hydrated poly(ethylene oxide)-poly(propylene oxide) block copolymers (Pluronic P105: EO(37)PO(56)EO(37)). Protonation of silica was used to vary the NP-polymer enthalpic interactions, while polar organic solvents (glycerol, DMSO, ethanol, and DMF) were used to modulate the NP-polymer entropic interactions. The introduction of deprotonated NPs in the place of an equal mass of water did not affect the lattice parameter of the PEO-PPO-PEO block copolymer hexagonal lyotropic liquid crystalline structures. However, the dispersion of protonated NPs led to an increase in the lattice parameter, which was attributed to stronger NP-polymer hydrogen bonding (enthalpic) interactions. Dispersion of protonated NPs into cylindrical structures formed by Pluronic P105 in 80/20 water/organic solvents does not influence the lattice parameter, different from the case of protonated NP in plain water. Organic solvents appear to screen the NP-polymer hydrogen bonding interactions.

  10. Thermally Reversible Physically Cross-Linked Hybrid Network Hydrogels Formed by Thermosensitive Hairy Nanoparticles.

    Science.gov (United States)

    Wright, Roger A E; Henn, Daniel M; Zhao, Bin

    2016-08-18

    This Article reports on thermally induced reversible formation of physically cross-linked, three-dimensional network hydrogels from aqueous dispersions of thermosensitive diblock copolymer brush-grafted silica nanoparticles (hairy NPs). The hairy NPs consisted of a silica core, a water-soluble polyelectrolyte inner block of poly(2-(methacryloyloxy)ethyltrimethylammonium iodide), and a thermosensitive poly(methoxydi(ethylene glycol) methacrylate) (PDEGMMA) outer block synthesized by sequential surface-initiated atom transfer radical polymerizations and postpolymerization quaternization of tertiary amine moieties. Moderately concentrated dispersions of these hairy nanoparticles in water underwent thermally induced reversible transitions between flowing liquids to self-supporting gels upon heating. The gelation was driven by the lower critical solution temperature (LCST) transition of the PDEGMMA outer block, which upon heating self-associated into hydrophobic domains acting as physical cross-linking points for the gel network. Rheological studies showed that the sol-gel transition temperature decreased with increasing hairy NP concentration, and the gelation was achieved at concentrations as low as 3 wt %. PMID:27455167

  11. Hybrid micellar hydrogels of a thermosensitive ABA triblock copolymer and hairy nanoparticles: effect of spatial location of hairy nanoparticles on gel properties.

    Science.gov (United States)

    Hu, Bin; Henn, Daniel M; Wright, Roger A E; Zhao, Bin

    2014-09-23

    This article reports a method for control of spatial location of nanoparticles (NPs) in hybrid micellar hydrogels of a thermosensitive ABA triblock copolymer and polymer brush-grafted NPs (hairy NPs), either inside or outside the core of micelles, and the study of the effect of different locations of NPs on gel properties. Two batches of thermosensitive polymer brush-grafted, 17 nm silica NPs with different lower critical solution temperatures (LCSTs) and a thermosensitive ABA triblock copolymer composed of a poly(ethylene oxide) central block and thermosensitive outer blocks (ABA-D) were synthesized. The different locations of NPs were achieved by controlling the LCST of hairy NPs (LCST(NP)) relative to that of the thermosensitive outer blocks of ABA-D (LCST(ABA)). When the LCST(NP) and LCST(ABA) were similar, the NPs resided in the core of micelles upon heating from below the LCST(NP) and LCST(ABA). When the LCST(NP) was significantly higher, the NPs were located outside the core of micelles as confirmed by fluorescent resonance energy transfer. The effects of different locations of hairy NPs and NP-to-polymer mass ratio on properties of hybrid micellar hydrogels formed from aqueous solutions of ABA-D with a concentration of 10 wt % and various amounts of hairy NPs were studied by rheological measurements. The sol-gel transition temperature (T(sol-gel)) and dynamic storage modulus G' of the gels with NPs inside the core of micelles did not change much with increasing the NP-to-polymer mass ratio. In contrast, the T(sol-gel) of gels with NPs in the interstitial space among micelles increased slightly and the G' decreased significantly with the increase of the NP-to-polymer ratio. The hairy NPs in the interstitial space appeared to affect the formation of polymer networks and increase the fraction of polymer loops, resulting in a lower density of bridging chains and thus a lower G'. In addition, for gels with NPs in the interstitial space, a noticeable increase in

  12. Aqueous Hybrids of Silica Nanoparticles and Hydrophobically Associating Hydrolyzed Polyacrylamide Used for EOR in High-Temperature and High-Salinity Reservoirs

    Directory of Open Access Journals (Sweden)

    Dingwei Zhu

    2014-06-01

    Full Text Available Water-soluble polymers are known to be used in chemically enhanced oil recovery (EOR processes, but their applications are limited in high-temperature and high-salinity oil reservoirs because of their inherent poor salt tolerance and weak thermal stability. Hydrophobic association of partially hydrolyzed polyacryamide (HAHPAM complexed with silica nanoparticles to prepare nano-hybrids is reported in this work. The rheological and enhanced oil recovery (EOR properties of such hybrids were studied in comparison with HAHPAM under simulated high-temperature and high-salinity oil reservoir conditions (T: 85 °C; total dissolved solids: 32,868 mg∙L−1; [Ca2+] + [Mg2+]: 873 mg∙L−1. It was found that the apparent viscosity and elastic modulus of HAHPAM solutions increased with addition of silica nanoparticles, and HAHPAM/silica hybrids exhibit better shear resistance and long-term thermal stability than HAHPAM in synthetic brine. Moreover, core flooding tests show that HAHPAM/silica hybrid has a higher oil recovery factor than HAHPAM solution.

  13. Hydrous Ruthenium Oxide Nanoparticles Anchored to Graphene and Carbon Nanotube Hybrid Foam for Supercapacitors

    OpenAIRE

    Wei Wang; Shirui Guo; Ilkeun Lee; Kazi Ahmed; Jiebin Zhong; Zachary Favors; Francisco Zaera; Mihrimah Ozkan; Ozkan, Cengiz S.

    2014-01-01

    In real life applications, supercapacitors (SCs) often can only be used as part of a hybrid system together with other high energy storage devices due to their relatively lower energy density in comparison to other types of energy storage devices such as batteries and fuel cells. Increasing the energy density of SCs will have a huge impact on the development of future energy storage devices by broadening the area of application for SCs. Here, we report a simple and scalable way of preparing a...

  14. Bio-inspired synthesis of hybrid silica nanoparticles templated from elastin-like polypeptide micelles

    Science.gov (United States)

    Han, Wei; MacEwan, Sarah R.; Chilkoti, Ashutosh; López, Gabriel P.

    2015-07-01

    The programmed self-assembly of block copolymers into higher order nanoscale structures offers many attractive attributes for the development of new nanomaterials for numerous applications including drug delivery and biosensing. The incorporation of biomimetic silaffin peptides in these block copolymers enables the formation of hybrid organic-inorganic materials, which can potentially enhance the utility and stability of self-assembled nanostructures. We demonstrate the design, synthesis and characterization of amphiphilic elastin-like polypeptide (ELP) diblock copolymers that undergo temperature-triggered self-assembly into well-defined spherical micelles. Genetically encoded incorporation of the silaffin R5 peptide at the hydrophilic terminus of the diblock ELP leads to presentation of the silaffin R5 peptide on the coronae of the micelles, which results in localized condensation of silica and the formation of near-monodisperse, discrete, sub-100 nm diameter hybrid ELP-silica particles. This synthesis method, can be carried out under mild reaction conditions suitable for bioactive materials, and will serve as the basis for the development and application of functional nanomaterials. Beyond silicification, the general strategies described herein may also be adapted for the synthesis of other biohybrid nanomaterials as well.The programmed self-assembly of block copolymers into higher order nanoscale structures offers many attractive attributes for the development of new nanomaterials for numerous applications including drug delivery and biosensing. The incorporation of biomimetic silaffin peptides in these block copolymers enables the formation of hybrid organic-inorganic materials, which can potentially enhance the utility and stability of self-assembled nanostructures. We demonstrate the design, synthesis and characterization of amphiphilic elastin-like polypeptide (ELP) diblock copolymers that undergo temperature-triggered self-assembly into well

  15. Platinum nanoparticles decorated robust binary transition metal nitride-carbon nanotubes hybrid as an efficient electrocatalyst for the methanol oxidation reaction

    Science.gov (United States)

    Zhan, Guohe; Fu, Zhenggao; Sun, Dalei; Pan, Zhanchang; Xiao, Chumin; Wu, Shoukun; Chen, Chun; Hu, Guanghui; Wei, Zhigang

    2016-09-01

    Titanium cobalt nitride (TiCoN)-CNTs hybrid support is prepared by a facile and efficient method, including a one-pot solvothermal process followed by a nitriding process, and this hybrid support is further decorated with Pt nanoparticles to catalyze the oxidation of methanol. The catalyst is characterized by X-ray diffraction (XRD), transmission electron microscopy (TEM), X-ray photoelectron spectroscopy (XPS) and electrochemical measurements. Notably, Pt/CNTs@TiCoN catalyst exhibits a much higher mass activity and durability than that of the conventional Pt/C (JM) for methanol oxidation. The experimental data indicates that the CNTs@TiCoN hybrid support combines the merits of the CNTs's high conductivity and the superb corrosion resistance of external TiCoN coating.

  16. Yolk-shell hybrid nanoparticles with magnetic and pH-sensitive properties for controlled anticancer drug delivery

    Science.gov (United States)

    Li, Shunxing; Zheng, Jianzhong; Chen, Dejian; Wu, Yijin; Zhang, Wuxiang; Zheng, Fengying; Cao, Jing; Ma, Heran; Liu, Yaling

    2013-11-01

    A facile and effective way for the preparation of nano-sized Fe3O4@graphene yolk-shell nanoparticles via a hydrothermal method is developed. Moreover, the targeting properties of the materials for anticancer drug (doxorubicin hydrochloride) delivery are investigated. Excitingly, these hybrid materials possess favorable dispersibility, good superparamagnetism (the magnetic saturation value is 45.740 emu g-1), high saturated loading capacity (2.65 mg mg-1), and effective loading (88.3%). More importantly, the composites exhibit strong pH-triggered drug release response (at the pH value of 5.6 and 7.4, the release rate was 24.86% and 10.28%, respectively) and good biocompatibility over a broad concentration range of 0.25-100 μg mL-1 (the cell viability was 98.52% even at a high concentration of 100 μg mL-1) which sheds light on their potentially bright future for bio-related applications.

  17. Tailored polymer-lipid hybrid nanoparticles for the delivery of drug conjugate: dual strategy for brain targeting.

    Science.gov (United States)

    Agrawal, Udita; Chashoo, Gousia; Sharma, Parduman Raj; Kumar, Ashok; Saxena, Ajit Kumar; Vyas, S P

    2015-02-01

    The object of the present study was to investigate the glioma targeting propensity of folic acid (F) decorated polymer-lipid hybrid nanoparticles (PLNs) encapsulating cyclo-[Arg-Gly-Asp-D-Phe-Lys] (cRGDfK) modified paclitaxel (PtxR-FPLNs). The prepared PLNs were supposed to bypass the blood-brain barrier (BBB) efficiently and subsequently target integrin rich glioma cells. The developed formulations were characterized for size, shape, drug entrapment efficiency, and in vitro release profile. PtxR-FPLNs demonstrated highest in vitro inhibitory effect, cell apoptosis and cell uptake. Pharmacokinetics and biodistribution studies showed efficacy of PtxR-FPLNs in vivo. In vivo anti-tumor studies clearly revealed that the median survival time for Balb/C mice treated with PtxR-FPLNs (42 days) was extended significantly as compared to PtxR-PLNs (35 days), free PtxR (18 days), Ptx-FPLNs (38 days), Ptx-PLNs (30 days), free Ptx (14 days) and control group (12 days). From the results it can be concluded that the developed dual targeted nanoformulation was able to efficiently cross the BBB and significantly deliver higher amounts of drug to brain tumor for better therapeutic outcome.

  18. Hybrid effects of zirconia nanoparticles with aluminum borate whiskers on mechanical properties of denture base resin PMMA.

    Science.gov (United States)

    Zhang, Xiu-Yin; Zhang, Xin-Jing; Huang, Zhuo-Li; Zhu, Bang-Shang; Chen, Rong-Rong

    2014-01-01

    The aim of this study was to investigate the hybrid effects of ZrO₂ nanoparticles (nano-ZrO₂) and aluminum borate whiskers (ABWs) on flexural strength and surface hardness of denture base resin, polymethyl methacrylate (PMMA). Both nano-ZrO₂ and ABWs were modified by silane coupling agent (Z6030) before being mixed with PMMA. Various amounts of silanized nano-ZrO₂ and ABWs were mixed with PMMA to prepare ZrO₂-ABW/PMMA composites. Flexural strength and surface hardness were evaluated using three- point bending test and Vickers hardness test respectively. Fractured surfaces were also observed by scanning electron microscopy (SEM). The mechanical behaviors of silanized ZrO₂-ABW/PMMA composites were significantly improved. Flexural strength reached a maximum value of 108.01 ± 5.54 MPa when 2 wt% of nano-ZrO₂ was mixed with ABWs at a ZrO₂/ABW ratio of 1:2, amounting to an increase of 52% when compared with pure PMMA. Surface hardness achieved a maximum value of 22.50 ± 0.86 MPa when 3 wt% of nano-ZrO₂ was mixed with ABWs at the same ZrO₂/ABW ratio, which was an increase of 27% when compared with pure PMMA.

  19. Neutral red interlinked gold nanoparticles/multiwalled carbon nanotubes hybrid nanomaterial and its application for the detection of NADH

    International Nuclear Information System (INIS)

    Graphical abstract: - Highlights: • Fabricated a nanostructured hybrid material of GNPs/neutral red/MWCNTs. • GNPs decorated on MWCNT template by using neutral red as interlinker for first time. • Nanocomposite modified electrode employed successfully as sensor for NADH. • The electrode has high stability as it does not involve any biological entity. - Abstract: A novel nanocomposite of gold nanoparticles/neutral red/MWCNTs was prepared which was used to modify glassy carbon electrode. The prepared nanocomposite was physically characterized by scanning electron microscopy, transmission electron microscopy, zeta potential measurement, energy dispersive X-ray, FTIR spectroscopy, UV–visible spectroscopy. Electrochemical characterization was done using cyclic voltammetry technique. The modified glassy carbon electrode showed electrocatalytic activity toward the oxidation of NADH in 0.1 M phosphate buffer solution, pH 5.0. The modified electrode has better adhesion over the electrode surface, good stability as no leaching of neutral red based nanocomposite was observed. The oxidation of NADH started at 0.37 V and reached maxima at 0.52 V at the modified electrode surface. So the prepared composite modified electrode can be applied as electrochemical sensor for NADH. The sensitivity and detection limits of the modified glassy carbon electrode were found to be 0.588 μA/mM and 5 × 10−7 at signal to noise ratio 3

  20. Engineering of a novel adjuvant based on lipid-polymer hybrid nanoparticles

    DEFF Research Database (Denmark)

    Rose, Fabrice; Wern, Jeanette Erbo; Ingvarsson, Pall Thor;

    2015-01-01

    The purpose of this study was to design a novel and versatile adjuvant intended for mucosal vaccination based on biodegradable poly(DL-lactic-co-glycolic acid) (PLGA) nanoparticles (NPs) modified with the cationic surfactant dimethyldioctadecylammonium (DDA) bromide and the immunopotentiator...... were engineered using an oil-in-water single emulsion method and a quality-by-design approach was adopted to define the optimal operating space (OOS). Four critical process parameters (CPPs) were identified, including the acetone concentration in the water phase, the stabilizer [polyvinylalcohol (PVA......)] concentration, the lipid-to-total solid ratio, and the total concentration. The CPPs were linked to critical quality attributes consisting of the particle size, polydispersity index (PDI), zeta-potential, thermotropic phase behavior, yield and stability. A central composite face-centered design was performed...

  1. Omnidirectional excitation of sidewall gap-plasmons in a hybrid gold-nanoparticle/aluminum-nanopore structure

    Science.gov (United States)

    Lumdee, Chatdanai; Kik, Pieter G.

    2016-06-01

    The gap-plasmon resonance of a gold nanoparticle inside a nanopore in an aluminum film is investigated in polarization dependent single particle microscopy and spectroscopy. Scattering and transmission measurements reveal that gap-plasmons of this structure can be excited and observed under normal incidence excitation and collection, in contrast to the more common particle-on-a-mirror structure. Correlation of numerical simulations with optical spectroscopy suggests that a local electric field enhancement factor in excess of 50 is achieved under normal incidence excitation, with a hot-spot located near the top surface of the structure. It is shown that the strong field enhancement from this sidewall gap-plasmon mode can be efficiently excited over a broad angular range. The presented plasmonic structure lends itself to implementation in low-cost, chemically stable, easily addressable biochemical sensor arrays providing large optical field enhancement factors.

  2. Silver nanoparticles coated with thioxanthone derivative as hybrid photoinitiating systems for free radical polymerization.

    Science.gov (United States)

    Nehlig, Emilie; Schneider, Raphaël; Vidal, Loic; Clavier, Gilles; Balan, Lavinia

    2012-12-21

    A new type of photoinitiator for free radical polymerization was synthesized and characterized. 2-(11-Mercaptoundecyloxy)thioxanthone (1) was anchored at the surface of silver nanoparticles (NPs), and the interaction of plasmon field generated in the immediate vicinity of Ag NPs carrying the chromophores was evaluated. The optical features and structure of the silver-initiator nanoassemblies (Ag@1) were characterized by UV-vis and fluorescence spectroscopy, X-ray diffraction (XRD), transmission electron microscopy (TEM), and X-ray photoelectron spectroscopy (XPS). TEM and XRD studies revealed the presence of ca. 5-6 nm diameter Ag NPs, and XPS also confirmed the successful anchorage of 1 at their periphery. The nanoassemblies Ag@1 were successfully used as macroinitiator for radical polymerization of acrylate monomers, triggered photochemically, to obtain Ag(0)-polyacrylate nanocomposite materials. The nanocomposite materials synthesized with the use of Ag@1 exhibit attractive possibilities for patterning the surface of thin films. PMID:23231028

  3. Synthesis of hybrid inorganic/organic nitric oxide-releasing silica nanoparticles for biomedical applications

    Science.gov (United States)

    Carpenter, Alexis Wells

    Nitric oxide (NO) is an endogenously produced free radical involved in a number of physiological processes. Thus, much research has focused on developing scaffolds that store and deliver exogenous NO. Herein, the synthesis of N-diazeniumdiolate-modified silica nanoparticles of various physical and chemical properties for biomedical applications is presented. To further develop NO-releasing silica particles for antimicrobial applications, a reverse microemulsion synthesis was designed to achieve nanoparticles of distinct sizes and similar NO release characteristics. Decreasing scaffold size resulted in improved bactericidal activity against Pseudomonas aeruginosa. Confocal microscopy revealed that the improved efficacy resulted from faster particle-bacterium association kinetics. To broaden the therapeutic potential of NO-releasing silica particles, strategies to tune NO release characteristics were evaluated. Initially, surface hydrophobicity and NO release kinetics were tuned by grafting hydrocarbon- and fluorocarbon-based silanes onto the surface of N-diazeniumdiolate-modified particles. The addition of fluorocarbons resulted in a 10x increase in the NO release half-life. The addition of short-chained hydrocarbons to the particle surface increased their stability in hydrophobic electrospun polyurethanes. Although NO release kinetics were longer than that of unmodified particles, durations were still limited to controls. The greater chemical flexibility of macromolecular scaffolds is a major advantage over LMW NO donors as it allows for the incorporation of multiple functionalities onto a single scaffold. To demonstrate this advantage, dual functional particles were synthesized by covalently binding quaternary ammonium (QA) functionalities to the surface of NO-releasing silica particles. The QA functionality proved more effective against Staphylococcus aureus than P. aeruginosa, and increasing alkyl chain length correlated with increased efficacy. Nitric oxide

  4. Enhanced Reduced Nicotinamide Adenine Dinucleotide electrocatalysis onto multi-walled carbon nanotubes-decorated gold nanoparticles and their use in hybrid biofuel cell

    Science.gov (United States)

    Aquino Neto, S.; Almeida, T. S.; Belnap, D. M.; Minteer, S. D.; De Andrade, A. R.

    2015-01-01

    We report the preparation of Au nanoparticles synthetized by different protocols and supported on the surface of multi-walled carbon nanotubes containing different functional groups, focusing on their electrochemical performance towards NADH oxidation, ethanol bioelectrocatalysis, and ethanol/O2 biofuel cell. We describe four different synthesis protocols: microwave-assisted heating, water-in-oil, and dendrimer-encapsulated nanoparticles using acid or thiol species in the extraction step. The physical characterization of the metallic nanoparticles indicated that both the synthetic protocol as well as the type of functional groups on the carbon nanotubes affect the final particle size (varying from 13.4 to 2.4 nm) and their distribution onto the carbon surface. Moreover, the electrochemical data indicated that these two factors also influence their performance toward the electrooxidation of NADH. We observed that the samples containing Au nanoparticles with smaller size leads to higher catalytic currents and also shifts the oxidation potential of the targeted reaction, which varied from 0.13 to -0.06 V vs Ag/AgCl. Ethanol/O2 biofuel cell tests indicated that the hybrid bioelectrodes containing smaller and better distributed Au nanoparticles on the surface of carbon nanotubes generates higher power output, confirming that the electrochemical regeneration of NAD+ plays an important role in the overall biofuel cell performance.

  5. nanoparticles

    Science.gov (United States)

    Andreu-Cabedo, Patricia; Mondragon, Rosa; Hernandez, Leonor; Martinez-Cuenca, Raul; Cabedo, Luis; Julia, J. Enrique

    2014-10-01

    Thermal energy storage (TES) is extremely important in concentrated solar power (CSP) plants since it represents the main difference and advantage of CSP plants with respect to other renewable energy sources such as wind, photovoltaic, etc. CSP represents a low-carbon emission renewable source of energy, and TES allows CSP plants to have energy availability and dispatchability using available industrial technologies. Molten salts are used in CSP plants as a TES material because of their high operational temperature and stability of up to 500°C. Their main drawbacks are their relative poor thermal properties and energy storage density. A simple cost-effective way to improve thermal properties of fluids is to dope them with nanoparticles, thus obtaining the so-called salt-based nanofluids. In this work, solar salt used in CSP plants (60% NaNO3 + 40% KNO3) was doped with silica nanoparticles at different solid mass concentrations (from 0.5% to 2%). Specific heat was measured by means of differential scanning calorimetry (DSC). A maximum increase of 25.03% was found at an optimal concentration of 1 wt.% of nanoparticles. The size distribution of nanoparticle clusters present in the salt at each concentration was evaluated by means of scanning electron microscopy (SEM) and image processing, as well as by means of dynamic light scattering (DLS). The cluster size and the specific surface available depended on the solid content, and a relationship between the specific heat increment and the available particle surface area was obtained. It was proved that the mechanism involved in the specific heat increment is based on a surface phenomenon. Stability of samples was tested for several thermal cycles and thermogravimetric analysis at high temperature was carried out, the samples being stable.

  6. Hybrid electrode obtained by sol-gel derived Ni0.3Co2.7O4 nanoparticles incorporated into polypyrrole: Electrocatalysis of O2 reduction

    Directory of Open Access Journals (Sweden)

    Mourad Mechouet

    2016-06-01

    Full Text Available A hybrid electrode was formed on glassy carbon (GC electrode with polypyrrole (PPy and mixed valence Ni0.3Co2.7O4 nanoparticles to study their behaviour towards the oxygen reduction reaction (ORR. The oxide nanoparticles were prepared by sol-gel route using various parameters and characterized by XRD, SEM, EDX and BET methods. The result showed that desired oxide was obtained and nanocrystallites exhibit a specific surface area ranging from 39 to 73 m2/g with diameter varying from 13 to 25 nm. The hybrid electrode was then fabricated by electropolymerization of pyrrole (Py in the presence of the smallest Ni0.3Co2.7O4 nanoparticles in KCl (0.15 mol/L at room temperature and characterized by EDX, SEM and LSV methods. Investigation of the hybrid electrode confirmed that O2 reduction mechanism changes by applying potential. Thus, at low overpotential the O2 reduction involves two electrons and provides H2O2, with cathodic transfer coefficients (β of 0.33 and exchange current density ( j0 of about 8×10-3 mA/cm2, while, at high overpotential H2O2 is further reduced into H2O. The results also show that sol-gel method led to the preparation of Ni0.3Co2.7O4 nanoparticles having a spinel structure with a desired stoichiometry which exhibits a high electrocatalytic activity for reducing oxygen mostly to H2O2.

  7. Towards the development of a novel bioinspired functional material: Synthesis and characterization of hybrid TiO{sub 2}/DHICA-melanin nanoparticles

    Energy Technology Data Exchange (ETDEWEB)

    Pezzella, Alessandro; Capelli, Luigia [Dept. of Chemical Sciences, Via Cintia 4, 80126 Napoli (Italy); Costantini, Aniello [Dept. of Materials and Production Engineering, Piazzale Tecchio 80, 80125 Napoli (Italy); Luciani, Giuseppina, E-mail: luciani@unina.it [Dept. of Materials and Production Engineering, Piazzale Tecchio 80, 80125 Napoli (Italy); Tescione, Fabiana; Silvestri, Brigida [Dept. of Materials and Production Engineering, Piazzale Tecchio 80, 80125 Napoli (Italy); Vitiello, Giuseppe [Dept. of Chemical Sciences, Via Cintia 4, 80126 Napoli (Italy); Branda, Francesco [Dept. of Materials and Production Engineering, Piazzale Tecchio 80, 80125 Napoli (Italy)

    2013-01-01

    A large number of recent literature data focus on modification/modulation of surface chemistry of inorganic materials in order to improve their functional properties. Melanins, a wide class of natural pigments, are recently emerging as a powerful organic component for developing bioinspired active material for a large number of applications from organoelectronics to bioactive compounds. Here we report the use of the approach referred as 'chimie douce', involving in situ formation of the hybrids through reactions of precursors under mild conditions, to prepare novel hybrid functional architectures based on eumelanin like 5,6 dihydroxyindole-2-carboxylic acid (DHICA) polymer and TiO{sub 2}. Two synthesis procedures were carried out to get DHICA-melanin coated TiO{sub 2} nanoparticles as well as mixed DHICA/TiO{sub 2} hybrid nanostructures. Such systems were characterized through EPR, FT-IR and fluorescence spectroscopy, thermogravimetric analysis (TGA), X-ray diffraction (XRD), and TEM microscopy in order to assess the effect of synthesis path as well as of DHICA content on structural, morphological and optical properties of TiO{sub 2} nanostructures. In particular, EPR, FT-IR spectra and TGA analysis confirmed the presence of DHICA-melanin in these samples. TEM measurements indicated the formation of the nanoparticles having relatively narrow size distribution with average particle size of about 10 nm. DHICA-melanin does act as a morphological agent affecting morphology of hybrid nanostructures. XRD analysis proved that TiO{sub 2} hybrid nanoparticles kept anatase structures for DHICA-melanin contents within the range of investigated compositions, i.e. up to 50% wt/wt. - Highlights: Black-Right-Pointing-Pointer TiO{sub 2}/DHICA melanin blends are novel hybrid functional architectures. Black-Right-Pointing-Pointer Two synthetic approaches were explored to produce TiO{sub 2}/DHICA nanostructures. Black-Right-Pointing-Pointer TiO{sub 2} nanorods prepared

  8. Electret Polyvinylidene Fluoride Nanofibers Hybridized by Polytetrafluoroethylene Nanoparticles for High-Efficiency Air Filtration.

    Science.gov (United States)

    Wang, Shan; Zhao, Xinglei; Yin, Xia; Yu, Jianyong; Ding, Bin

    2016-09-14

    Airborne particulate matter (PM) pollution has become a severe environmental concern calling for electret fibrous materials with high filtration efficiency and low pressure drop. However, restraining the dissipation of the electric charges in service to ensure the stabilized electrostatic force of the fibers for effectively adsorbing particles is extremely important and also challenging. Herein, we report novel electret nanofibrous membranes with numerous charges and desirable charge stability using polyvinylidene fluoride (PVDF) as the matrix polymer and polytetrafluoroethylene nanoparticles (PTFE NPs) as an inspiring charge enhancer through the in situ charging technology of electrospinning. Benefiting from the employment of PTFE NPs and optimized injection energy, the fibrous membranes are endowed with elevated surface potentials from 0.42 to 3.63 kV and reduced decrement of charges from 75.4 to 17.5%, which contribute to the ameliorative stability of filtration efficiency. Significantly, an electret mechanism is proposed, while deepened depth of the energy level and incremental polarized dipole charges with increasing PTFE NP concentrations and injection energy have been confirmed through the measurement of open-circuit thermally stimulated discharge and surface potential decay. Ultimately, the resultant fibrous membrane exhibited a high filtration efficiency of 99.972%, a low pressure drop of 57 Pa, a satisfactory quality factor of 0.14 Pa(-1), and superior long-term service performance. The successful fabrication of such an intriguing material may provide a new approach for the design and development of electret materials for PM2.5 governance. PMID:27552028

  9. Solution-processed zinc oxide nanoparticles/single-walled carbon nanotubes hybrid thin-film transistors

    Science.gov (United States)

    Liu, Fangmei; Sun, Jia; Qian, Chuan; Hu, Xiaotao; Wu, Han; Huang, Yulan; Yang, Junliang

    2016-09-01

    Solution-processed thin-film transistors (TFTs) are the essential building blocks for manufacturing the low-cost and large-area consumptive electronics. Herein, solution-processed TFTs based on the composites of zinc oxide (ZnO) nanoparticles and single-walled carbon nanotubes (SWCNTs) were fabricated by the methods of spin-coating and doctor-blading. Through controlling the weight of SWCNTs, the ZnO/SWCNTs TFTs fabricated by spin-coating demonstrated a field-effect mobility of 4.7 cm2/Vs and a low threshold voltage of 0.8 V, while the TFTs devices fabricated by doctor-blading technique showed reasonable electrical performance with a mobility of 0.22 cm2/Vs. Furthermore, the ion-gel was used as an efficient electrochemical gate dielectric because of its large electric double-layer capacitance. The operating voltage of all the TFTs devices is as low as 4.0 V. The research suggests that ZnO/SWCNTs TFTs have the potential applications in low-cost, large-area and flexible consumptive electronics, such as chemical-biological sensors and smart label.

  10. Incorporating different vegetable oils into an aqueous dispersion of hybrid organic nanoparticles

    Energy Technology Data Exchange (ETDEWEB)

    Samyn, Pieter, E-mail: Pieter.Samyn@fobawi.uni-freiburg.de [Albert-Luedwigs-University Freiburg, Institute for Forest Utilization (Germany); Schoukens, Gustaaf [Ghent University, Department of Textiles (Belgium); Stanssens, Dirk; Vonck, Leo; Van den Abbeele, Henk [Topchim N.V. (Belgium)

    2012-08-15

    Different vegetable oils including soy oil, high-oleic sunflower oil, corn oil, castor oil (CO), rapeseed oil, and hydrogenated CO were added to the imidization reaction of poly(styrene-maleic anhydride) or SMA, with ammonium hydroxide in aqueous medium. The oils favorably reduce viscosity during ammonolysis of the anhydride moieties and increase the maximum solid content of the dispersed imidized SMA to at least 50 wt%, compared to a maximum of 35 wt% for pure imidized SMA. The viscosity of imidized SMA with polyunsaturated oils was generally larger than for monosaturated oils, but it was highest for COs due to high contents of hydroxyl groups. Depending on the oil reactivity, homogeneous or core-shell nanoparticles with 20-60 nm diameters formed. The interactions of oil and organic phase were studied by Fourier-transform infrared spectroscopy, indicating qualitative variances between different oils, the fraction imidized SMA and remaining fraction of ammonolyzed SMA without leakage of oil upon diluting the dispersion and precipitation at low pH. A quantitative analysis with calculation of imide contents, amounts of reacted oil and chemical interactions was made by Fourier-transform-Raman spectroscopy suggesting that most interactions take place around the unsaturated oil moieties and ammonolyzed anhydride.

  11. Amplified electrochemical detection of nucleic acid hybridization via selective preconcentration of unmodified gold nanoparticles.

    Science.gov (United States)

    Li, Yuan; Tian, Rui; Zheng, Xingwang; Huang, Rongfu

    2016-08-31

    The common drawback of optical methods for rapid detection of nucleic acid by exploiting the differential affinity of single-/double-stranded nucleic acids for unmodified gold nanoparticles (AuNPs) is its relatively low sensitivity. In this article, on the basis of selective preconcentration of AuNPs unprotected by single-stranded DNA (ssDNA) binding, a novel electrochemical strategy for nucleic acid sequence identification assay has been developed. Through detecting the redox signal mediated by AuNPs on 1, 6-hexanedithiol blocked gold electrode, the proposed method is able to ensure substantial signal amplification and a low background current. This strategy is demonstrated for quantitative analysis of the target microRNA (let-7a) in human breast adenocarcinoma cells, and a detection limit of 16 fM is readily achieved with desirable specificity and sensitivity. These results indicate that the selective preconcentration of AuNPs for electrochemical signal readout can offer a promising platform for the detection of specific nucleic acid sequence. PMID:27506344

  12. Hybrid optoacoustic and ultrasound biomicroscopy monitors’ laser-induced tissue modifications and magnetite nanoparticle impregnation

    Science.gov (United States)

    Estrada, Héctor; Sobol, Emil; Baum, Olga; Razansky, Daniel

    2014-12-01

    Tissue modification under laser radiation is emerging as one of the advanced applications of lasers in medicine, with treatments ranging from reshaping and regeneration of cartilage to normalization of the intraocular pressure. Laser-induced structural alterations can be studied using conventional microscopic techniques applied to thin specimen. Yet, development of non-invasive imaging methods for deep tissue monitoring of structural alterations under laser radiation is of great importance, especially for attaining efficient feedback during the procedures. We developed a fast scanning biomicroscopy system that can simultaneously deliver both optoacoustic and pulse-echo ultrasound contrast from intact tissues and show that both modalities allow manifesting the laser-induced changes in cartilage and sclera. Furthermore, images of the sclera samples reveal a crater developing around the center of the laser-irradiated spot as well as a certain degree of thickening within the treated zone, presumably due to pore formation. Finally, we were able to observe selective impregnation of magnetite nanoparticles into the cartilage, thus demonstrating a possible contrast enhancement approach for studying specific treatment effects. Overall, the new imaging approach holds promise for development of noninvasive feedback control systems that could guarantee efficacy and safety of laser-based medical procedures.

  13. Formation of gel of preformed size-selected titanium-oxo-alkoxy nanoparticles: towards organic-inorganic hybrid material with efficient interfacial electron transfer

    International Nuclear Information System (INIS)

    We report on preparation of a new organic–inorganic hybrid material with high photonic sensitivity, of which the inorganic component is gel of preformed size-selected titanium-oxo-alkoxy (TOA) nanoparticles. The inorganic nanoparticles of 5 nm size are generated in perfect micromixing conditions and assembled into the gel network in monomer HEMA (2-hydroxyethyl methacrylate) solutions at sufficiently slow input of water molecules in neutral pH conditions. The gelation is found to compete with precipitation and is promoted by an increase of the nanoparticle concentration. As a result, homogeneous optical-grade gels are obtained at titanium molar concentrations of 1.5 M and higher. After the organic polymerization, the organicinorganic pHEMA-TOA hybrids (pHEMA = poly(2-hydroxyethyl methacrylate)) show a high quantum yield of photoinduced charges separation (Ti3+/absorbed photons) and storage capacity (Ti3+/Ti4+), respectively 75% and 25%, which confirm the importance of the material nanoscale morphology control. (paper)

  14. Electrocatalytic glucose oxidation via hybrid nanomaterial catalyst of multi-wall TiO2 nanotubes supported Ni(OH)2 nanoparticles: Optimization of the loading level

    International Nuclear Information System (INIS)

    Highlights: • Multi-wall TiO2 nanotube supported Ni(OH)2 nanoparticles, Ni(OH)2/TNTs, was prepared and investigated as anode electro-catalysts for glucose oxidation. • Ni(OH)2-24.2%/TNTs obtains the best catalytic activity. • Compared with Ni(OH)2, the current density of Ni(OH)2-24.2%/TNTs increased 5.9 times in 0.1 M NaOH solution. - Abstract: The novel hybrid nanomaterial catalyst of multi-wall TiO2 nanotube supported Ni(OH)2 nanoparticles (Ni(OH)2/TNTs) was prepared through hydrothermal method and investigated as anode electro-catalysts for glucose oxidation. The nanostructure was characterized by X-ray diffraction (XRD), scanning electron microscope (SEM), transmission electron microscopy (TEM), thermogravimetry-differential thermal analysis (TGA) and nitrogen adsorption-desorption (BET-BJH). The electrochemical performance was measured by a range of electrochemical measurements. Compared with Ni(OH)2, the current density of Ni(OH)2/TNTs modified GC electrode increased 5.9 times in 0.1 M NaOH solution. The results indicated that the synthesized nanoparticles exhibited good electro-catalytic activity and stability for glucose oxidation. Meanwhile, the hybrid nanomaterial of Ni(OH)2/TNTs may be a potential candidate catalyst for direct glucose fuel cell

  15. Preparation of an aptamer based organic-inorganic hybrid monolithic column with gold nanoparticles as an intermediary for the enrichment of proteins.

    Science.gov (United States)

    Zhao, Jin-Cheng; Zhu, Qing-Yun; Zhao, Ling-Yu; Lian, Hong-Zhen; Chen, Hong-Yuan

    2016-08-01

    A novel strategy for the preparation of an aptamer based organic-inorganic hybrid affinity monolithic column was developed successfully using gold nanoparticles (GNPs) as an intermediary for a sandwich structure to realize the functional modification of the surface of the monolithic matrix. This monolithic matrix was facilely pre-synthesized via one-step co-condensation. Due to the high surface-to-volume ratio of GNPs and the large specific surface area of the hybrid matrix, the average coverage density of aptamers on the hybrid monolith reached 342 pmol μL(-1). With the combination of an aptamer based hybrid affinity monolithic column and enzymatic chromogenic assay, the quantitation and detection limits of thrombin were as low as 5 nM and 2 nM, respectively. These results indicated that the GNPs attached monolith provided a novel technique to immobilize aptamers on an organic-inorganic hybrid monolith and it could be used to achieve highly selective recognition and determination of trace proteins. PMID:27307035

  16. A novel surface-enhanced Raman spectroscopy substrate based on a large area of MoS2 and Ag nanoparticles hybrid system

    Science.gov (United States)

    Chen, P. X.; Qiu, H. W.; Xu, S. C.; Liu, X. Y.; Li, Z.; Hu, L. T.; Li, C. H.; Guo, J.; Jiang, S. Z.; Huo, Y. Y.

    2016-07-01

    Few layers MoS2 were directly synthesized on Ag nanoparticles (AgNPs) by thermal decomposion method to fabricate a MoS2/AgNPs hybrid system for surface-enhanced Raman scattering (SERS). The MoS2/AgNPs hybrid system shows high performance in terms of sensitivity, signal-to-noise ratio, reproducibility and stability. The minimum detected concentration from MoS2/AgNPs hybrid system for R6 G can reach 10-9 M, which is one order of magnitude lower than that from AgNPs system. The hybrid system shows the reasonable linear response between the Raman intensity and concentration that R2 is reached to 0.988. The maximum deviations of SERS intensities from 20 positions of the SERS substrate are less than 13%. Besides, the hybrid system has a good stability, the Raman intensity only drop by 20% in a month. This work can provide a basis for the fabrication of novel SERS substrates.

  17. Gold nanoparticles-induced enhancement of the analytical response of an electrochemical biosensor based on an organic-inorganic hybrid composite material.

    Science.gov (United States)

    Barbadillo, M; Casero, E; Petit-Domínguez, M D; Vázquez, L; Pariente, F; Lorenzo, E

    2009-12-15

    The design and characterization of a new organic-inorganic hybrid composite material for glucose electrochemical sensing are described. This material is based on the entrapment of both gold nanoparticles (AuNPs) and glucose oxidase, which was chosen as a model, into a sol-gel matrix. The addition of spectroscopic grade graphite to this system, which confers conductivity, leads to the development of a material particularly attractive for electrochemical biosensor fabrication. The characterization of the hybrid composite material was performed using atomic force microscopy and scanning electron microscopy techniques. This composite material was applied to the determination of glucose in presence of hydroxymethylferrocene as a redox mediator. The system exhibits a clear electrocatalytic activity towards glucose, allowing its determination at 250 mV vs Ag/AgCl. The performance of the resulting enzyme biosensor was evaluated in terms of sensitivity, detection limit, linear response range, stability and accuracy. Finally, the enhancement of the analytical response of the resulting biosensor induced by the presence of gold nanoparticles was evaluated by comparison with a similar organic-inorganic hybrid composite material without AuNPs.

  18. Cellulose acetate fibers covered by CdS nanoparticles for hybrid solar cell applications

    Energy Technology Data Exchange (ETDEWEB)

    Cortina, Hugo; Martinez-Alonso, Claudia [Centro de Investigacion en Energia, UNAM, Priv. Xochicalco S/N, Temixco, Morelos 62580 (Mexico); Castillo-Ortega, Monica [Universidad de Sonora, Hermosillo, Sonora 83000 (Mexico); Hu, Hailin, E-mail: hzh@cie.unam.mx [Centro de Investigacion en Energia, UNAM, Priv. Xochicalco S/N, Temixco, Morelos 62580 (Mexico)

    2012-09-20

    In this work cellulose acetate (CA) fibers with a diameter of approximately 1 {mu}m were immersed in a cadmium sulfide (CdS) precursor solution. After 3 h the original white color CA fibers became yellow and maintained the same form, suggesting the deposition of CdS on fiber surface. SEM images showed that CA fibers were covered by uniformly sized CdS nanoparticles of approximately 100 nm. XRD and optical absorption spectra indicated that they contained mostly cubic crystalline phase with the optical band gap of 2.43 eV. CdS coated CA fibers, called CdS(CA) fibers, were dispersed in a polar dispersant (dimethyl sulfoxide, DMSO) and then mixed with a poly(3-hexylthiophene) (P3HT) solution in a non-polar solvent (dichlorobenzene, DCB). The mixture was cast onto a transparent conductive glass substrate (Indium-Tin-Oxide, ITO), and after solvent evaporation a thin layer of CdS(CA)-P3HT composite was formed. It is observed that the volume relation between the polar dispersant and non-polar solvent influences the solubility of the P3HT product in the composite coating and the photovoltaic performance of the corresponding cell as well. The mass ratio between CdS(CA) fibers and P3HT in the composite layer affects the optical absorption of the composite. The best photovoltaic performance was obtained in CdS(CA)-P3HT based cells with a volume relation between DCB and DMSO of 3.5-1, a mass ratio between CdS(CA) and P3HT of 1:1, and a rapid drying process for composite coatings.

  19. Quaternized Carboxymethyl Chitosan-Based Silver Nanoparticles Hybrid: Microwave-Assisted Synthesis, Characterization and Antibacterial Activity

    Directory of Open Access Journals (Sweden)

    Siqi Huang

    2016-06-01

    Full Text Available A facile, efficient, and eco-friendly approach for the preparation of uniform silver nanoparticles (Ag NPs was developed. The synthesis was conducted in an aqueous medium exposed to microwave irradiation for 8 min, using laboratory-prepared, water-soluble quaternized carboxymethyl chitosan (QCMC as a chemical reducer and stabilizer and silver nitrate as the silver source. The structure of the prepared QCMC was characterized using Fourier transform infrared (FT-IR and 1H nuclear magnetic resonance (NMR. The formation, size distribution, and dispersion of the Ag NPs in the QCMC matrix were determined using X-ray diffraction (XRD, X-ray photoelectron spectroscopy (XPS, ultraviolet-visible (UV-Vis, transmission electron microscopy (TEM, and field emission scanning electron microscope (FESEM analysis, and the thermal stability and antibacterial properties of the synthesized QCMC-based Ag NPs composite (QCMC-Ag were also explored. The results revealed that (1 QCMC was successfully prepared by grafting quaternary ammonium groups onto carboxymethyl chitosan (CMC chains under microwave irradiation in water for 90 min and this substitution appeared to have occurred at -NH2 sites on C2 position of the pyranoid ring; (2 uniform and stable spherical Ag NPs could be synthesized when QCMC was used as the reducing and stabilizing agent; (3 Ag NPs were well dispersed in the QCMC matrix with a narrow size distribiution in the range of 17–31 nm without aggregation; and (4 due to the presence of Ag NPs, the thermal stability and antibacterial activity of QCMC-Ag were dramatically improved relative to QCMC.

  20. Synthesis of Ag/CNT hybrid nanoparticles and fabrication of their Nylon-6 polymer nanocomposite fibers for antimicrobial applications

    Energy Technology Data Exchange (ETDEWEB)

    Rangari, Vijaya K; Mohammad, Ghouse M; Jeelani, Shaik [Materials Science and Engineering, Center for Advanced Materials, Tuskegee University, Tuskegee, AL 36088 (United States); Hundley, Angel; Vig, Komal; Singh, Shree Ram; Pillai, Shreekumar, E-mail: rangariv@tuskegee.edu [Center for NanoBiotechnology Research, Alabama State University, Montgomery, AL 36104 (United States)

    2010-03-05

    Ag-coated CNTs hybrid nanoparticles (Ag/CNTs) were prepared by ultrasonic irradiation of dimethylformamide (DMF) and silver (I) acetate precursors in the presence of CNTs. The morphology of Ag/CNTs was characterized using x-ray diffraction and transmission electron microscopy (TEM) techniques. The Nylon-6 powder and 1 wt% Ag/CNTs mixture was dispersed uniformly using a noncontact spinning technique. The dried mixture was melted in a single screw extrusion machine and then extruded through an orifice. Extruded filaments were later stretched and stabilized by sequentially passing them through a set of tension adjusters and a secondary heater. The Nylon-6/Ag/CNT hybrid polymer nanocomposite (HPNC) fibers, which were of {approx} 80 {mu}m size, were tested for their tensile properties. The failure stress and modulus of the extruded HPNC fibers (doped with 1% Ag/CNTs) was about 72.19 % and 342.62% higher than the neat extruded Nylon-6 fiber, respectively. DSC results indicated an increase in the thermal stability and crystallization for HPNC fibers. The antibacterial activity of the Ag-coated CNTs, commercial Ag, neat Nylon-6 and plain CNTs were evaluated. Ag-coated CNTs at 25 {mu}g demonstrated good antimicrobial activity against four common bacterial pathogens as tested by the Kirby-Bauer assay. The mean diameters of the zones of inhibition were 27.9 {+-} 6.72 mm, 19.4 {+-} 3.64 mm, 21.9 {+-} 4.33 mm, and 24.1 {+-} 4.14 mm, respectively, for Staphylococcus aureus, Streptococcus pyogenes, Escherichia coli and Salmonella enterica serovar Typhimurium. By comparison, those obtained using the broad spectrum antibiotic amoxicillin-clavulanic acid were 37.7 {+-} 2.13 mm, 28.6 {+-} 4.27 mm, 22.6 {+-} 1.27 mm, and 27.0 {+-} 1.41 mm, respectively, for the same strains. The zones of inhibition obtained for Nylon-6 Ag-coated CNT powder at 25 {mu}g were also high, ranging from 15.2 to 25.3 mm in contrast to commercial silver or neat Nylon-6, which did not inhibit the bacterial

  1. Excitonic emission of hybrid nanosystem ''spherical semiconductor quantum dot + spherical metal nanoparticle''

    International Nuclear Information System (INIS)

    The hybrid nanosystem composed of a spherical metal nanoparticle (NP) and a spherical semiconductor quantum dot (QD) of a direct-band semiconductor with a cubic lattice structure and a fourfold degenerate valence band G8 has been studied. The excitonic emission of the system is considered as a sum of contributions from point dipoles located at the QD lattice sites. The description of the QD + NP nanosystem, nonspherical as a whole, is based on using three spherical coordinate systems and finding the relations between the coefficients of multipole expansions of electromagnetic (EM) fields in those systems. The origins of two of them are fixed at the centers of NP and QD, and their polar axes are directed along the line connecting the centers. The orientation of the third coordinate system with the origin in the QD is determined by the orientation of the QD crystal lattice. It is shown that, unlike the electric scalar potential, which is induced by the exciton state in the QD and looks like a point-dipole potential, the EM field of the QD excitonic emission cannot be represented as that of a point dipole emission, because it contains only dipole, quadrupole, and octupole components. The multiple scattering, between the NP and the QD, of the EM field emitted by the QD is taken into account. The dependences of the excitonic emission efficiency on the separation distance between the QD and the NP surfaces are calculated in a particular case of the CdTe QD and a silver or gold NP for various QD and NP sizes

  2. Self-assembled organic–inorganic magnetic hybrid adsorbent ferrite based on cyclodextrin nanoparticles

    Directory of Open Access Journals (Sweden)

    Ângelo M. L. Denadai

    2012-11-01

    Full Text Available Organic–inorganic magnetic hybrid materials (MHMs combine a nonmagnetic and a magnetic component by means of electrostatic interactions or covalent bonds, and notable features can be achieved. Herein, we describe an application of a self-assembled material based on ferrite associated with β-cyclodextrin (Fe-Ni/Zn/βCD at the nanoscale level. This MHM and pure ferrite (Fe-Ni/Zn were used as an adsorbent system for Cr3+ and Cr2O72− ions in aqueous solutions. Prior to the adsorption studies, both ferrites were characterized in order to determine the particle size distribution, morphology and available binding sites on the surface of the materials. Microscopy analysis demonstrated that both ferrites present two different size domains, at the micro- and nanoscale level, with the latter being able to self-assemble into larger particles. Fe-Ni/Zn/βCD presented smaller particles and a more homogeneous particle size distribution. Higher porosity for this MHM compared to Fe-Ni/Zn was observed by Brunauer–Emmett–Teller isotherms and positron-annihilation-lifetime spectroscopy. Based on the pKa values, potentiometric titrations demonstrated the presence of βCD in the inorganic matrix, indicating that the lamellar structures verified by transmission electronic microscopy can be associated with βCD assembled structures. Colloidal stability was inferred as a function of time at different pH values, indicating the sedimentation rate as a function of pH. Zeta potential measurements identified an amphoteric behavior for the Fe-Ni/Zn/βCD, suggesting its better capability to remove ions (cations and anions from aqueous solutions compared to that of Fe-Ni/Zn.

  3. Schottky diodes between Bi2S3 nanorods and metal nanoparticles in a polymer matrix as hybrid bulk-heterojunction solar cells

    International Nuclear Information System (INIS)

    We report the use of metal-semiconductor Schottky junctions in a conjugated polymer matrix as solar cells. The Schottky diodes, which were formed between Bi2S3 nanorods and gold nanoparticles, efficiently dissociated photogenerated excitons. The bulk-heterojunction (BHJ) devices based on such metal-semiconductor Schottky diodes in a polymer matrix therefore acted as an efficient solar cell as compared to the devices based on only the semiconductor nanorods in the polymer matrix or when gold nanoparticles were added separately to the BHJs. In the latter device, gold nanoparticles offered plasmonic enhancement due to an increased cross-section of optical absorption. We report growth and characteristics of the Schottky junctions formed through an intimate contact between Bi2S3 nanorods and gold nanoparticles. We also report fabrication and characterization of BHJ solar cells based on such heterojunctions. We highlight the benefit of using metal-semiconductor Schottky diodes over only inorganic semiconductor nanorods or quantum dots in a polymer matrix in forming hybrid BHJ solar cells

  4. Schottky diodes between Bi2S3 nanorods and metal nanoparticles in a polymer matrix as hybrid bulk-heterojunction solar cells

    Science.gov (United States)

    Saha, Sudip K.; Pal, Amlan J.

    2015-07-01

    We report the use of metal-semiconductor Schottky junctions in a conjugated polymer matrix as solar cells. The Schottky diodes, which were formed between Bi2S3 nanorods and gold nanoparticles, efficiently dissociated photogenerated excitons. The bulk-heterojunction (BHJ) devices based on such metal-semiconductor Schottky diodes in a polymer matrix therefore acted as an efficient solar cell as compared to the devices based on only the semiconductor nanorods in the polymer matrix or when gold nanoparticles were added separately to the BHJs. In the latter device, gold nanoparticles offered plasmonic enhancement due to an increased cross-section of optical absorption. We report growth and characteristics of the Schottky junctions formed through an intimate contact between Bi2S3 nanorods and gold nanoparticles. We also report fabrication and characterization of BHJ solar cells based on such heterojunctions. We highlight the benefit of using metal-semiconductor Schottky diodes over only inorganic semiconductor nanorods or quantum dots in a polymer matrix in forming hybrid BHJ solar cells.

  5. Schottky diodes between Bi{sub 2}S{sub 3} nanorods and metal nanoparticles in a polymer matrix as hybrid bulk-heterojunction solar cells

    Energy Technology Data Exchange (ETDEWEB)

    Saha, Sudip K.; Pal, Amlan J., E-mail: sspajp@iacs.res.in [Department of Solid State Physics, Indian Association for the Cultivation of Science, Jadavpur, Kolkata 700032 (India)

    2015-07-07

    We report the use of metal-semiconductor Schottky junctions in a conjugated polymer matrix as solar cells. The Schottky diodes, which were formed between Bi{sub 2}S{sub 3} nanorods and gold nanoparticles, efficiently dissociated photogenerated excitons. The bulk-heterojunction (BHJ) devices based on such metal-semiconductor Schottky diodes in a polymer matrix therefore acted as an efficient solar cell as compared to the devices based on only the semiconductor nanorods in the polymer matrix or when gold nanoparticles were added separately to the BHJs. In the latter device, gold nanoparticles offered plasmonic enhancement due to an increased cross-section of optical absorption. We report growth and characteristics of the Schottky junctions formed through an intimate contact between Bi{sub 2}S{sub 3} nanorods and gold nanoparticles. We also report fabrication and characterization of BHJ solar cells based on such heterojunctions. We highlight the benefit of using metal-semiconductor Schottky diodes over only inorganic semiconductor nanorods or quantum dots in a polymer matrix in forming hybrid BHJ solar cells.

  6. CO 2 Capture Capacity and Swelling Measurements of Liquid-like Nanoparticle Organic Hybrid Materials via Attenuated Total Reflectance Fourier Transform Infrared Spectroscopy

    KAUST Repository

    Park, Youngjune

    2012-01-12

    Novel nanoparticle organic hybrid materials (NOHMs), which are comprised of organic oligomers or polymers tethered to an inorganic nanosized cores of various sizes, have been synthesized, and their solvating property for CO 2 was investigated using attenuated total reflectance (ATR) Fourier transform infrared (FT-IR) spectroscopy. Simultaneous measurements of CO 2 capture capacity and swelling behaviors of polyetheramine (Jeffamine M-2070) and its corresponding NOHMs (NOHM-I-PE2070) were reported at temperatures of (298, 308, 323 and 353) K and CO 2 pressure conditions ranging from (0 to 5.5) MPa. The polymeric canopy, or polymer bound to the nanoparticle surface, showed significantly less swelling behavior with enhanced or comparable CO 2 capture capacity compared to pure unbound polyetheramine. © 2011 American Chemical Society.

  7. A method of layer-by-layer gold nanoparticle hybridization in a quartz crystal microbalance DNA sensing system used to detect dengue virus

    International Nuclear Information System (INIS)

    Dengue virus (DENV) is nowadays the most important arthropod-spread virus affecting humans existing in more than 100 countries worldwide. A rapid and sensitive detection method for the early diagnosis of infectious dengue virus urgently needs to be developed. In the present study, a circulating-flow quartz crystal microbalance (QCM) biosensing method combining oligonucleotide-functionalized gold nanoparticles (i.e. AuNP probes) used to detect DENV has been established. In the DNA-QCM method, two kinds of specific AuNP probes were linked by the target sequences onto the QCM chip to amplify the detection signal, i.e. oscillatory frequency change (ΔF) of the QCM sensor. The target sequences amplified from the DENV genome act as a bridge for the layer-by-layer AuNP probes' hybridization in the method. Besides being amplifiers of the detection signal, the specific AuNP probes used in the DNA-QCM method also play the role of verifiers to specifically recognize their target sequences in the detection. The effect of four AuNP sizes on the layer-by-layer hybridization has been evaluated and it is found that 13 nm AuNPs collocated with 13 nm AuNPs showed the best hybridization efficiency. According to the nanoparticle application, the DNA-QCM biosensing method was able to detect dengue viral RNA in virus-contaminated serum as plaque titers being 2 PFU ml-1 and a linear correlation (R2 = 0.987) of ΔF versus virus titration from 2 x 100 to 2 x 106 PFU ml-1 was found. The sensitivity and specificity of the present DNA-QCM method with nanoparticle technology showed it to be comparable to the fluorescent real-time PCR methods. Moreover, the method described herein was shown to not require expensive equipment, was label-free and highly sensitive.

  8. A method of layer-by-layer gold nanoparticle hybridization in a quartz crystal microbalance DNA sensing system used to detect dengue virus

    Science.gov (United States)

    Chen, Sz-Hau; Chuang, Yao-Chen; Lu, Yi-Chen; Lin, Hsiu-Chao; Yang, Yun-Liang; Lin, Chih-Sheng

    2009-05-01

    Dengue virus (DENV) is nowadays the most important arthropod-spread virus affecting humans existing in more than 100 countries worldwide. A rapid and sensitive detection method for the early diagnosis of infectious dengue virus urgently needs to be developed. In the present study, a circulating-flow quartz crystal microbalance (QCM) biosensing method combining oligonucleotide-functionalized gold nanoparticles (i.e. AuNP probes) used to detect DENV has been established. In the DNA-QCM method, two kinds of specific AuNP probes were linked by the target sequences onto the QCM chip to amplify the detection signal, i.e. oscillatory frequency change (ΔF) of the QCM sensor. The target sequences amplified from the DENV genome act as a bridge for the layer-by-layer AuNP probes' hybridization in the method. Besides being amplifiers of the detection signal, the specific AuNP probes used in the DNA-QCM method also play the role of verifiers to specifically recognize their target sequences in the detection. The effect of four AuNP sizes on the layer-by-layer hybridization has been evaluated and it is found that 13 nm AuNPs collocated with 13 nm AuNPs showed the best hybridization efficiency. According to the nanoparticle application, the DNA-QCM biosensing method was able to detect dengue viral RNA in virus-contaminated serum as plaque titers being 2 PFU ml-1 and a linear correlation (R2 = 0.987) of ΔF versus virus titration from 2 × 100 to 2 × 106 PFU ml-1 was found. The sensitivity and specificity of the present DNA-QCM method with nanoparticle technology showed it to be comparable to the fluorescent real-time PCR methods. Moreover, the method described herein was shown to not require expensive equipment, was label-free and highly sensitive.

  9. Optical and electrochemical evaluation of colloidal Au nanoparticle-ITO hybrid optically transparent electrodes and their application to attenuated total reflectance spectroelectrochemistry

    Energy Technology Data Exchange (ETDEWEB)

    Richardson, John N.; Aguilar, Zoraida; Kaval, Necati; Andria, Sara E.; Shtoyko, Tanya; Seliskar, Carl J.; Heineman, William R

    2003-12-15

    Colloidal Au nanoparticle monolayers covalently deposited on conductive layers of indium tin oxide (ITO) were fabricated and evaluated as optically transparent electrodes (OTEs) for spectroelectrochemical applications. Specifically, the electrodes were characterized using UV-Vis spectroscopy and cyclic voltammetry; comparisons are made with other types of hybrid ITO optically transparent electrodes. The optical modulation of surface-bound colloidal Au in response to potential cycling over a wide potential window (0.6 to -1.0 V) was acquired in an attenuated total reflectance (ATR) spectroelectrochemical cell. Finally, uptake of a model analyte, tris-(2,2'-bipyridyl)ruthenium(II) chloride, into a Nafion charge selective film spin coated onto the colloidal Au-ITO hybrid electrode was examined using ATR absorbance spectroelectrochemistry. Dependence of uptake on film thickness is addressed, and non-optimized detection limits of 10 nM are reported.

  10. Hybrid solar cells based on poly(3-hexylthiophene) and electrospun TiO2 nanofibers modified with CdS nanoparticles

    Institute of Scientific and Technical Information of China (English)

    Shingchung Lo; Zhike Liu; Jinhua Li; Helen Laiwa Chan; Feng Yann

    2013-01-01

    Organic-inorganic hybrid solar cells based on poly(3-hexylthiophene) and electrospun TiO2 nanofibers were fabricated by solution process. The efficiency of the device was improved by modifying CdS nanoparticles on the surface of TiO2 by electrochemical method. The CdS layer can lead to the increase of both open circuit voltage and short circuit current of the device, which are attributed to enhanced exciton dissociation and light absorption and suppressed carrier recombination by CdS at the heterojunction. However, too thick CdS layer led to increased series resistance and decreased efficiency of the device. Therefore, the optimum condition of the CdS deposition was obtained, which increased the power conversion efficiency of the device for about 50%. Our results indicate that the surface modification on the inorganic semiconductor layer is an effect way to improve the performance of the hybrid solar cells.

  11. Hybrid membrane with TiO2 based bio-catalytic nanoparticle suspension system for the degradation of bisphenol-A.

    Science.gov (United States)

    Hou, Jingwei; Dong, Guangxi; Luu, Belinda; Sengpiel, Robert G; Ye, Yun; Wessling, Matthias; Chen, Vicki

    2014-10-01

    The removal of micropollutant in wastewater treatment has become a key environmental challenge for many industrialized countries. One approach is to use enzymes such as laccase for the degradation of micropollutants such as bisphenol-A. In this work, laccase was covalently immobilized on APTES modified TiO2 nanoparticles, and the effects of particle modification on the bio-catalytic performance were examined and optimized. These bio-catalytic particles were then suspended in a hybrid membrane reactor for BPA removal with good BPA degradation efficiency observed. Substantial improvement in laccase stability was achieved in the hybrid system compared with free laccase under simulated harsh industrial wastewater treatment conditions (such as a wide range of pH and presence of inhibitors). Kinetic study provided insight of the effect of immobilization on the bio-degradation reaction. PMID:25084046

  12. Interface-directed self-assembly of gold nanoparticles and fabrication of hybrid hollow capsules by interfacial cross-linking polymerization.

    Science.gov (United States)

    Tian, Jia; Yuan, Liang; Zhang, Mingming; Zheng, Fan; Xiong, Qingqing; Zhao, Hanying

    2012-06-26

    Amphiphilic gold nanoparticles (AuNPs) were produced at liquid-liquid interface via ligand exchange between hydrophilic AuNPs and disulfide-containing polymer chains. By using oil droplets as templates, hybrid hollow capsules with AuNPs on the surfaces were obtained after interfacial cross-linking polymerization. The volume ratio of toluene to water exerts an important effect on the size of capsules. The average size of the capsules increases with the volume ratio. Transmission electron microscopy (TEM), scanning electron microscopy (SEM), and atomic force microscopy (AFM) were used to characterize the hollow structures. In this research, not only one-component but also multicomponent hollow capsules were prepared by copolymerization of acrylamide and hybrid AuNPs at liquid-liquid interface. Because of the improvement in hydrophilicity of the hollow capsules, the average size of multicomponent capsules is bigger than one-component ones in aqueous solution.

  13. One-step fabrication of antibacterial (silver nanoparticles/poly(ethylene oxide)) - Polyurethane bicomponent hybrid nanofibrous mat by dual-spinneret electrospinning

    Energy Technology Data Exchange (ETDEWEB)

    Tijing, Leonard D., E-mail: ltijing@jbnu.ac.kr [Division of Mechanical Design Engineering, Chonbuk National University, Jeonju, Jeonbuk 561-756 (Korea, Republic of); Ruelo, Michael Tom G. [Division of Mechanical Design Engineering, Chonbuk National University, Jeonju, Jeonbuk 561-756 (Korea, Republic of); Amarjargal, Altangerel [Department of Bionanosystem Engineering, Chonbuk National University, Jeonju, Jeonbuk 561-756 (Korea, Republic of); Power Engineering School, Mongolian University of Science and Technology, Ulaanbaatar (Mongolia); Pant, Hem Raj [Department of Bionanosystem Engineering, Chonbuk National University, Jeonju, Jeonbuk 561-756 (Korea, Republic of); Department of Engineering Science and Humanities, Institute of Engineering, Pulchowk Campus, Tribhuvan University, Kathmandu (Nepal); Park, Chan-Hee [Department of Bionanosystem Engineering, Chonbuk National University, Jeonju, Jeonbuk 561-756 (Korea, Republic of); Kim, Cheol Sang, E-mail: chskim@jbnu.ac.kr [Division of Mechanical Design Engineering, Chonbuk National University, Jeonju, Jeonbuk 561-756 (Korea, Republic of); Department of Bionanosystem Engineering, Chonbuk National University, Jeonju, Jeonbuk 561-756 (Korea, Republic of)

    2012-06-15

    The one-step electrospinning fabrication of novel materials with added functionalities is being widely studied because of their wide array of applications. Here, the fabrication of a hybrid, bimodal nanofibrous mat made of two polymeric nanofibers: polyurethane (PU) and silver (Ag) nanoparticle (NP) -in situ - decorated poly(ethylene oxide) (PEO) utilizing an angled dual-spinneret electrospinning system is reported. Silver nitrate (AgNO{sub 3}) is in-situ reduced in high-molecular weight PEO, and Ag NPs with sizes from 6 to 90 nm as checked by scanning electron microscoy and transmission electron microscopy, are subsequently formed on the surface of PEO nanofibers depending on the reduction time. Successful fabrication of bicomponent polymer matrices (PU and PEO) in the hybrid mat is confirmed by Fourier transform infrared spectroscopy. Metallic Ag NPs are verified to be present in the hybrid mats by energy dispersive X-ray spectroscopy and ultraviolet-vis spectroscopy, showing plasmon resonance band peaks at 415 and 425 nm. The hybrid nanofibrous mat containing Ag NPs with an average size of 8 nm (i.e., reduction time of 3 h) exhibits strong antibacterial activity. - Graphical abstract: Black-Small-Square Highlights: Black-Right-Pointing-Pointer We have fabricated a bicomponent nanofibrous mat by dual-spinneret electrospinning. Black-Right-Pointing-Pointer The hybrid mat was composed of PU and PEO nanofibers with bimodal fiber sizes. Black-Right-Pointing-Pointer The PEO nanofibers are selectively decorated with Ag NPs without the use of chemicals. Black-Right-Pointing-Pointer High MW PEO was used as both reductant and template for the formed Ag NPs. Black-Right-Pointing-Pointer The hybrid mat containing Ag NPs exhibits strong antibacterial activity.

  14. Elaboration of hybrid materials by templating with mineral liquid crystals stabilization of a mixed sol of YSZ nanoparticles and V2O5 ribbon-like colloids

    International Nuclear Information System (INIS)

    The purpose of this PhD was to investigate innovative soft chemistry ways to prepare hybrid materials with ordered nano-structures. Concretely, research were conducted on the development of a hybrid material made of an yttria-stabilized zirconia (YSZ) matrix templated by a mineral liquid crystal, namely V2O5. In aqueous solutions, vanadium oxide exhibits ribbon-like colloids of typical dimensions 1 nm x 25 nm x 500 nm, stabilized by a strong negative surface charge. Above a critical concentration, the anisotropic colloids assemble into a nematic liquid crystal, whose domains can be oriented within the same direction over a macroscopic range under a weak magnetic field. The idea is to use V2O5 anisotropic colloids as a template for a hybrid material, taking advantage of their ordering behavior. Preliminary experiments revealed a strong reactivity between molecular compounds of zirconium and vanadium oxide. Therefore, the studies were directed toward the preparation of a mixed colloidal sol containing YSZ nanoparticles and vanadium oxide ribbon-like colloids, as a precursor sol for the intended hybrid material. The YSZ nanoparticles are obtained through an outstanding hydrothermal synthesis leading to a stable suspension of nanocrystalline particles of ca. 5 nm, in pure water. Providing a mixed sol of YSZ and V2O5 is a key challenge for it implies the co-stabilization of two types of colloids having different shape, size and surface properties. Besides, the existence of V2O5 in its ribbon-like form requires acidic conditions and very low ionic strength. The first part of this work was then dedicated to the study of electro-steric stabilization of zirconia suspension by addition of acidic poly-electrolytes. Different polymers with carboxylic and/or sulfonic acidic functions were investigated. Based on zeta potential measurements and adsorption isotherms, the influence of molecular weight and polymer charge were discussed. Among the studied polymers, poly vinylsulfonic

  15. A paper-based resonance energy transfer nucleic acid hybridization assay using upconversion nanoparticles as donors and quantum dots as acceptors

    International Nuclear Information System (INIS)

    Highlights: • Covalent immobilization of upconversion nanoparticles on paper. • LRET-based label free DNA detection using quantum dots as acceptors. • Use of polyethylene glycol to eliminate non-specific adsorption of quantum dots. • Improved analytical performance compared to analogous assays. - Abstract: Monodisperse aqueous upconverting nanoparticles (UCNPs) were covalently immobilized on aldehyde modified cellulose paper via reduction amination to develop a luminescence resonance energy transfer (LRET)-based nucleic acid hybridization assay. This first account of covalent immobilization of UCNPs on paper for a bioassay reports an optically responsive method that is sensitive, reproducible and robust. The immobilized UCNPs were decorated with oligonucleotide probes to capture HPRT1 housekeeping gene fragments, which in turn brought reporter conjugated quantum dots (QDs) in close proximity to the UCNPs for LRET. This sandwich assay could detect unlabeled oligonucleotide target, and had a limit of detection of 13 fmol and a dynamic range spanning nearly 3 orders of magnitude. The use of QDs, which are excellent LRET acceptors, demonstrated improved sensitivity, limit of detection, dynamic range and selectivity compared to similar assays that have used molecular fluorophores as acceptors. The selectivity of the assay was attributed to the decoration of the QDs with polyethylene glycol to eliminate non-specific adsorption. The kinetics of hybridization were determined to be diffusion limited and full signal development occurred within 3 min

  16. A paper-based resonance energy transfer nucleic acid hybridization assay using upconversion nanoparticles as donors and quantum dots as acceptors

    Energy Technology Data Exchange (ETDEWEB)

    Doughan, Samer; Uddayasankar, Uvaraj; Krull, Ulrich J., E-mail: ulrich.krull@utoronto.ca

    2015-06-09

    Highlights: • Covalent immobilization of upconversion nanoparticles on paper. • LRET-based label free DNA detection using quantum dots as acceptors. • Use of polyethylene glycol to eliminate non-specific adsorption of quantum dots. • Improved analytical performance compared to analogous assays. - Abstract: Monodisperse aqueous upconverting nanoparticles (UCNPs) were covalently immobilized on aldehyde modified cellulose paper via reduction amination to develop a luminescence resonance energy transfer (LRET)-based nucleic acid hybridization assay. This first account of covalent immobilization of UCNPs on paper for a bioassay reports an optically responsive method that is sensitive, reproducible and robust. The immobilized UCNPs were decorated with oligonucleotide probes to capture HPRT1 housekeeping gene fragments, which in turn brought reporter conjugated quantum dots (QDs) in close proximity to the UCNPs for LRET. This sandwich assay could detect unlabeled oligonucleotide target, and had a limit of detection of 13 fmol and a dynamic range spanning nearly 3 orders of magnitude. The use of QDs, which are excellent LRET acceptors, demonstrated improved sensitivity, limit of detection, dynamic range and selectivity compared to similar assays that have used molecular fluorophores as acceptors. The selectivity of the assay was attributed to the decoration of the QDs with polyethylene glycol to eliminate non-specific adsorption. The kinetics of hybridization were determined to be diffusion limited and full signal development occurred within 3 min.

  17. In situ plasma sputtering synthesis of ZnO nanorods-Ag nanoparticles hybrids and their application in non-enzymatic hydrogen peroxide sensing

    Science.gov (United States)

    Zhang, Dan; Zhang, Yuxia; Yang, Chi; Ge, Cunwang; Wang, Yuanhong; Wang, Hao; Liu, Hongying

    2015-08-01

    In this paper, ZnO nanorods-Ag nanoparticles hybrids were first synthesized via a facile, rapid, and in situ plasma sputtering method without using any silver precursor. The obtained materials were then characterized by scanning electron microscopy, high-resolution transmission electron microscopy, energy-dispersive x-ray spectroscopy, and cyclic voltammetry. Based on the electrochemical catalytic properties of the obtained nanohybrids, a non-enzymatic hydrogen peroxide biosensor was constructed by immobilizing the obtained ZnO nanorods-Ag nanoparticles hybrids on the surface of a glassy carbon electrode. Under optimal conditions, the resulting biosensor displayed a good response for H2O2 with a linear range of 0.2 to 12.8 mM, and a detection limit of 7.8 μM at a signal-to-noise ratio of 3. In addition, it exhibited excellent anti-interference ability and fast response. The current work provides a feasible platform to fabricate a variety of non-enzymatic biosensors.

  18. In situ plasma sputtering synthesis of ZnO nanorods-Ag nanoparticles hybrids and their application in non-enzymatic hydrogen peroxide sensing.

    Science.gov (United States)

    Zhang, Dan; Zhang, Yuxia; Yang, Chi; Ge, Cunwang; Wang, Yuanhong; Wang, Hao; Liu, Hongying

    2015-08-21

    In this paper, ZnO nanorods-Ag nanoparticles hybrids were first synthesized via a facile, rapid, and in situ plasma sputtering method without using any silver precursor. The obtained materials were then characterized by scanning electron microscopy, high-resolution transmission electron microscopy, energy-dispersive x-ray spectroscopy, and cyclic voltammetry. Based on the electrochemical catalytic properties of the obtained nanohybrids, a non-enzymatic hydrogen peroxide biosensor was constructed by immobilizing the obtained ZnO nanorods-Ag nanoparticles hybrids on the surface of a glassy carbon electrode. Under optimal conditions, the resulting biosensor displayed a good response for H2O2 with a linear range of 0.2 to 12.8 mM, and a detection limit of 7.8 μM at a signal-to-noise ratio of 3. In addition, it exhibited excellent anti-interference ability and fast response. The current work provides a feasible platform to fabricate a variety of non-enzymatic biosensors.

  19. Dual-targeting hybrid nanoparticles for the delivery of SN38 to Her2 and CD44 overexpressed human gastric cancer

    Science.gov (United States)

    Yang, Zhe; Luo, Huiyan; Cao, Zhong; Chen, Ya; Gao, Jinbiao; Li, Yingqin; Jiang, Qing; Xu, Ruihua; Liu, Jie

    2016-06-01

    Gastric cancer (GC), particularly of the type with high expression of both human epidermal growth factor receptor 2 (Her2) and cluster determinant 44 (CD44), is one of the most malignant human tumors which causes a high mortality rate due to rapid tumor growth and metastasis. To develop effective therapeutic treatments, a dual-targeting hybrid nanoparticle (NP) system was designed and constructed to deliver the SN38 agent specifically to human solid gastric tumors bearing excessive Her2 and CD44. The hybrid NPs consist of a particle core made of the biodegradable polymer PLGA and a lipoid shell prepared by conjugating the AHNP peptides and n-hexadecylamine (HDA) to the carboxyl groups of hyaluronic acid (HA). Upon encapsulation of the SN38 agent in the NPs, the AHNP peptides and HA on the NP surface allow preferential delivery of the drug to gastric cancer cells (e.g., HGC27 cells) by targeting Her2 and CD44. Cellular uptake and in vivo biodistribution experiments verified the active targeting and prolonged in vivo circulation properties of the dual-targeting hybrid NPs, leading to enhanced accumulation of the drug in tumors. Furthermore, the anti-proliferation mechanism studies revealed that the inhibition of the growth and invasive activity of HGC27 cells was not only attributed to the enhanced cellular uptake of dual-targeting NPs, but also benefited from the suppression of CD44 and Her2 expression by HA and AHNP moieties. Finally, intravenous administration of the SN38-loaded dual-targeting hybrid NPs induced significant growth inhibition of HGC27 tumor xenografted in nude mice compared with a clinical antitumor agent, Irinotecan (CPT-11), and the other NP formulations. These results demonstrate that the designed dual-targeting hybrid NPs are promising for targeted anti-cancer drug delivery to treat human gastric tumors over-expressing Her2 and CD44.Gastric cancer (GC), particularly of the type with high expression of both human epidermal growth factor receptor

  20. Development of aptamer-conjugated magnetic graphene/gold nanoparticle hybrid nanocomposites for specific enrichment and rapid analysis of thrombin by MALDI-TOF MS.

    Science.gov (United States)

    Xiong, Ya; Deng, Chunhui; Zhang, Xiangmin

    2014-11-01

    Simple, rapid and sensitive analysis of thrombin (a tumor biomarker) in complex samples is quite clinical relevant and essential for the development of disease diagnosis and pharmacotherapy. Herein, we developed a novel method based on aptamer-conjugated magnetic graphene/gold nanoparticles nanocomposites (MagG@Au) for specific enrichment and rapid analysis of thrombin in biological samples using MALDI-TOF-MS. At first, gold nanoparticles were compactly deposited on PDDA functionalized magnetic graphene through electrostatic interaction. Afterwards, aptamer was easily conjugated to gold nanoparticles via Au-S bond formation. The as-made aptamer-conjugated nanocomposites took advantage of the magnetism of magnetic graphene, the high affinity and specificity of aptamer, facilitating a high-efficient separation and enrichment of thrombin. More importantly, due to the large surface area of the hybrid substrate, the average coverage density of aptamer achieved 0.34 nmol/mg, which enhanced the thrombin binding capacity and the recovery of thrombin in real samples. In turn, the enriched thrombin attributed to the sensitive output of MALDI-TOF mass spectrometry signal, 0.085 ng μL(-1) (2.36 nM) thrombin could be detected. This proposed method has a relatively wide linear relation ranging from 0.1 ng μL(-1) to 10 ng μL(-1), and satisfactory specificity. The proposed high-throughput method based on MALDI-TOF MS is expected to the application in the disease biomarker detection and clinical diagnosis. PMID:25127596

  1. Electrogenerated Chemiluminescence Behavior of Au nanoparticles-hybridized Pb (II) metal-organic framework and its application in selective sensing hexavalent chromium.

    Science.gov (United States)

    Ma, Hongmin; Li, Xiaojian; Yan, Tao; Li, Yan; Liu, Haiyang; Zhang, Yong; Wu, Dan; Du, Bin; Wei, Qin

    2016-01-01

    In this work, a novel electrochemiluminescence (ECL) sensor based on Au nanoparticles-hybridized Pb (II)-β-cyclodextrin (Pb-β-CD) metal-organic framework for detecting hexavalent chromium (Cr(VI)) was developed. Pb-β-CD shows excellent ECL behavior and unexpected reducing ability towards Au ions. Au nanoparticles could massively form on the surface of Pb-β-CD (Au@Pb-β-CD) without use of any additional reducing agent. In the presence of coreactant K2S2O8, the ECL emission of Pb-β-CD was enhanced by the formation of Au nanoparticles. Cr(VI) can collisionally quench the ECL behavior of Au@Pb-β-CD/S2O8(2-) system and the detection mechanism was investigated. This ECL sensor is found to have a linear response in the range of 0.01-100 μM and a low detection limit of 3.43 nM (S/N = 3) under the optimal conditions. These results suggest that metal-organic framework Au@Pb-β-CD has great potential in extending the application in the ECL field as an efficient luminophore. PMID:26902375

  2. Visible light-driven photocatalytic degradation of the organic pollutant methylene blue with hybrid palladium–fluorine-doped titanium oxide nanoparticles

    International Nuclear Information System (INIS)

    The synthesis of mesoporous aggregates of titanium oxide nanoparticles (F0) is described using a very cheap and simple synthetic protocol. This consists of the reaction of titanium tetraisopropoxide and a solution of HNO3 in water (pH 2.0) and subsequent filtration. In addition, fluorine-doped titanium oxides (F1, F2, F5 and F10) were synthesized using the same method, adding increasing amounts of NaF to the reaction mixture (avoiding the use of expensive reagents such as NH4F or trifluoroacetic acid). The resulting materials were calcined at different temperatures (500, 600 and 650 °C) giving particles sized between 10 and 20 nm. Furthermore, a hybrid F-doped TiO2 with supported palladium nanoparticles of ca. 20 nm (F5-500-Pd1) was synthesized by grafting an organometallic palladium(II) salt namely [Pd(cod)Cl2] (cod = 1,5-cyclooctadiene). Photocatalytic studies of the degradation of methylene blue (MB) were carried out under UV light using all the synthesized material (non-doped an F-doped TiO2), observing that the increase in the quantity of fluorine has a positive effect on the photocatalytic activity. F5-500 is apparently the material which has the most convenient structural properties (in terms of surface area and anatase/rutile ratio) and thus a higher photocatalytic activity. The hybrid material F-doped TiO2–Pd nanoparticles (F5-500-Pd1) has a lower band gap value than F5-500, and thus photocatalytic degradation of MB under LED visible light was achieved using F5-500-Pd1 as photocatalyst

  3. Visible light-driven photocatalytic degradation of the organic pollutant methylene blue with hybrid palladium–fluorine-doped titanium oxide nanoparticles

    Energy Technology Data Exchange (ETDEWEB)

    Lázaro-Navas, Sonia; Prashar, Sanjiv; Fajardo, Mariano; Gómez-Ruiz, Santiago, E-mail: santiago.gomez@urjc.es [Universidad Rey Juan Carlos, Departamento de Biología y Geología, Física y Química Inorgánica, ESCET (Spain)

    2015-02-15

    The synthesis of mesoporous aggregates of titanium oxide nanoparticles (F0) is described using a very cheap and simple synthetic protocol. This consists of the reaction of titanium tetraisopropoxide and a solution of HNO{sub 3} in water (pH 2.0) and subsequent filtration. In addition, fluorine-doped titanium oxides (F1, F2, F5 and F10) were synthesized using the same method, adding increasing amounts of NaF to the reaction mixture (avoiding the use of expensive reagents such as NH{sub 4}F or trifluoroacetic acid). The resulting materials were calcined at different temperatures (500, 600 and 650 °C) giving particles sized between 10 and 20 nm. Furthermore, a hybrid F-doped TiO{sub 2} with supported palladium nanoparticles of ca. 20 nm (F5-500-Pd1) was synthesized by grafting an organometallic palladium(II) salt namely [Pd(cod)Cl{sub 2}] (cod = 1,5-cyclooctadiene). Photocatalytic studies of the degradation of methylene blue (MB) were carried out under UV light using all the synthesized material (non-doped an F-doped TiO{sub 2}), observing that the increase in the quantity of fluorine has a positive effect on the photocatalytic activity. F5-500 is apparently the material which has the most convenient structural properties (in terms of surface area and anatase/rutile ratio) and thus a higher photocatalytic activity. The hybrid material F-doped TiO{sub 2}–Pd nanoparticles (F5-500-Pd1) has a lower band gap value than F5-500, and thus photocatalytic degradation of MB under LED visible light was achieved using F5-500-Pd1 as photocatalyst.

  4. Synthesis and characterization of organic–inorganic hybrid materials prepared by sol–gel and containing Zn{sub x}Cd{sub 1−x}S nanoparticles prepared by a colloidal method

    Energy Technology Data Exchange (ETDEWEB)

    Gonçalves, Luis F.F.F., E-mail: luisf@quimica.uminho.pt [Centro de Química, Departamento de Química, Universidade do Minho, 4710-057 Braga (Portugal); Centro de Física, Departamento de Física, Universidade do Minho, 4710-057 Braga (Portugal); Silva, Carlos J.R. [Centro de Química, Departamento de Química, Universidade do Minho, 4710-057 Braga (Portugal); Kanodarwala, Fehmida K.; Stride, John A. [School of Chemistry, University of New South Wales, Sydney 2052 (Australia); Pereira, Mário R.; Gomes, Maria J.M. [Centro de Física, Departamento de Física, Universidade do Minho, 4710-057 Braga (Portugal)

    2013-12-15

    Nanocomposite materials based on a hybrid organic–inorganic ureasilicate matrix doped with Zn{sub x}Cd{sub 1−x}S nanoparticles were prepared. Zn{sub x}Cd{sub 1−x}S nanoparticles with different compositions (Zn/Cd mole ratio) were prepared through a colloidal method using reverse micelles. Previously to dispersion within the matrix precursors used to prepare the hybrid gel composite, the nanoparticles surface was modified in order to improve compatibility and stability with the matrix and to assure the preservation of the original optical properties of the nanoparticles. The matrix was obtained by the reaction between a silicon alkoxide modified by an isocyanate group and a di-amine functionalized oligopolyoxyethylene (Jeffamine ED-600), which by subsequent hydrolysis and condensation reactions formed a mechanically stable and highly transparent solid network containing the Zn{sub x}Cd{sub 1−x}S nanoparticles. The materials were characterized by absorption, steady-state and time-resolved photoluminescence spectroscopy and by HRTEM. The obtained nanocomposites show a high transparency in the visible range accounting for the good dispersion of the nanoparticles within the matrix. The results obtained confirmed the preservation of the original optical properties of the nanoparticles after their incorporation into the ureasilicate matrix, showing that the developed method is suitable for the production of materials with potential applications in which it is necessary to take advantage of the optical properties of the nanoparticles incorporated. The HRTEM analysis confirmed that the dispersed nanoparticles show a high level of crystallinization. -- Highlights: • Synthesis of a hybrid ureasilicate matrix doped with Zn{sub x}Cd{sub 1−x}S nanoparticles. • The influence of the composition of the nanoparticles plays an important role in the optical properties of the nanocomposites. • Preservation of the optical properties of the nanoparticles associated with

  5. Magnetic Fe3O4/Ag Hybrid Nanoparticles as Surface-Enhanced Raman Scattering Substrate for Trace Analysis of Furazolidone in Fish Feeds

    Directory of Open Access Journals (Sweden)

    Wansong Yu

    2014-01-01

    Full Text Available Nanoparticles (NPs composed of ferromagnetic and noble metal materials show dual functions of magnetic activity and local surface plasmon response and have great potential as substrates for surface-enhanced Raman scattering (SERS in trace analysis. Easy-to-prepare superparamagnetic Fe3O4/Ag hybrid NPs were synthesized and optimized by adjusting the ratio of silver particles aggregated with APTMS-modified Fe3O4 NPs. The hybrid NPs were assembled under an external magnetic field before being used as substrate for SERS analysis. The SERS spectral features of furazolidone standard solution were clearly identified at concentrations as low as 40 ng mL−1, and furazolidone in fish feeds could be detected at 500 ng g−1. The results indicated that the Fe3O4/Ag hybrid NPs as SERS substrates had a great potential for detection of trace amount of furazolidone and other prohibited or restricted antibiotics in the animal and fish feeds.

  6. Sol-gel encapsulation of binary Zn(II) compounds in silica nanoparticles. Structure-activity correlations in hybrid materials targeting Zn(II) antibacterial use.

    Science.gov (United States)

    Halevas, E; Nday, C M; Kaprara, E; Psycharis, V; Raptopoulou, C P; Jackson, G E; Litsardakis, G; Salifoglou, A

    2015-10-01

    In the emerging issue of enhanced multi-resistant properties in infectious pathogens, new nanomaterials with optimally efficient antibacterial activity and lower toxicity than other species attract considerable research interest. In an effort to develop such efficient antibacterials, we a) synthesized acid-catalyzed silica-gel matrices, b) evaluated the suitability of these matrices as potential carrier materials for controlled release of ZnSO4 and a new Zn(II) binary complex with a suitably designed well-defined Schiff base, and c) investigated structural and textural properties of the nanomaterials. Physicochemical characterization of the (empty-loaded) silica-nanoparticles led to an optimized material configuration linked to the delivery of the encapsulated antibacterial zinc load. Entrapment and drug release studies showed the competence of hybrid nanoparticles with respect to the a) zinc loading capacity, b) congruence with zinc physicochemical attributes, and c) release profile of their zinc load. The material antimicrobial properties were demonstrated against Gram-positive (Staphylococcus aureus, Bacillus subtilis, Bacillus cereus) and negative (Escherichia coli, Pseudomonas aeruginosa, Xanthomonas campestris) bacteria using modified agar diffusion methods. ZnSO4 showed less extensive antimicrobial behavior compared to Zn(II)-Schiff, implying that the Zn(II)-bound ligand enhances zinc antimicrobial properties. All zinc-loaded nanoparticles were less antimicrobially active than zinc compounds alone, as encapsulation controls their release, thereby attenuating their antimicrobial activity. To this end, as the amount of loaded zinc increases, the antimicrobial behavior of the nano-agent improves. Collectively, for the first time, sol-gel zinc-loaded silica-nanoparticles were shown to exhibit well-defined antimicrobial activity, justifying due attention to further development of antibacterial nanotechnology.

  7. A binary functional substrate for enrichment and ultrasensitive SERS spectroscopic detection of folic acid using graphene oxide/Ag nanoparticle hybrids.

    Science.gov (United States)

    Ren, Wen; Fang, Youxing; Wang, Erkang

    2011-08-23

    Herein graphene oxide/Ag nanoparticle hybrids (GO/PDDA/AgNPs) were fabricated according to a self-assembly procedure. Using the obtained GO/PDDA/AgNPs as SERS substrates, an ultrasensitive and label-free detection of folic acid in water and serum was demonstrated based on the inherent SERS spectra of folic acid. The modified graphene oxide exhibited strong enrichment of folic acid due to the electrostatic interaction, and the self-assembled Ag nanoparticles greatly enhanced the SERS spectra of folic acid, both of which led to an ultrahigh sensitivity. Therefore, although the SERS enhancement of p-ATP on GO/PDDA/AgNPs was weaker than that on Ag nanoparticles, the SERS signals of folic acid on GO/PDDA/AgNPs were much stronger than that on Ag nanoparticles. To improve the detection, the concentration of GO/PDDA/AgNPs was optimized to reduce background of the graphene oxide. The SERS spectra of the folic acid showed that the minimum detected concentration of folic acid in water was as low as 9 nM with a linear response range from 9 to 180 nM. To estimate the feasibility of the detection method based on GO/PDDA/AgNPs for the practical applications, diluted serum containing different concentrations of folic acid was taken as real samples. It was established that the sensitivity and the linear range for the folic acid in serum were comparable to that in water. This ultrasensitive and label-free SERS detection of folic acid based on GO/PDDA/AgNPs offers great potential for practical applications of medicine and biotechnology.

  8. Real-time electrochemical detection of hydrogen peroxide secretion in live cells by Pt nanoparticles decorated graphene-carbon nanotube hybrid paper electrode.

    Science.gov (United States)

    Sun, Yimin; He, Kui; Zhang, Zefen; Zhou, Aijun; Duan, Hongwei

    2015-06-15

    In this work, we develop a new type of flexible and lightweight electrode based on highly dense Pt nanoparticles decorated free-standing graphene-carbon nanotube (CNT) hybrid paper (Pt/graphene-CNT paper), and explore its practical application as flexible electrochemical biosensor for the real-time tracking hydrogen peroxide (H2O2) secretion by live cells. For the fabrication of flexible nanohybrid electrode, the incorporation of CNT in graphene paper not only improves the electrical conductivity and the mechanical strength of graphene paper, but also increases its surface roughness and provides more nucleation sites for metal nanoparticles. Ultrafine Pt nanoparticles are further decorated on graphene-CNT paper by well controlled sputter deposition method, which offers several advantages such as defined particle size and dispersion, high loading density and strong adhesion between the nanoparticles and the substrate. Consequently, the resultant flexible Pt/graphene-CNT paper electrode demonstrates a variety of desirable electrochemical properties including large electrochemical active surface area, excellent electrocatalytic activity, high stability and exceptional flexibility. When used for nonenzymatic detection of H2O2, Pt/graphene-CNT paper exhibits outstanding sensing performance such as high sensitivity, selectivity, stability and reproducibility. The sensitivity is 1.41 µA µM(-1) cm(-2) with a linear range up to 25 µM and a low detection limit of 10 nM (S/N=3), which enables the resultant biosensor for the real-time tracking H2O2 secretion by live cells macrophages.

  9. A method of layer-by-layer gold nanoparticle hybridization in a quartz crystal microbalance DNA sensing system used to detect dengue virus

    Energy Technology Data Exchange (ETDEWEB)

    Chen, S-H; Chuang, Y-C; Lu, Y-C; Lin, H-C; Yang, Y-L; Lin, C-S [Department of Biological Science and Technology, National Chiao Tung University, Hsinchu 30068, Taiwan (China)], E-mail: lincs@mail.nctu.edu.tw

    2009-05-27

    Dengue virus (DENV) is nowadays the most important arthropod-spread virus affecting humans existing in more than 100 countries worldwide. A rapid and sensitive detection method for the early diagnosis of infectious dengue virus urgently needs to be developed. In the present study, a circulating-flow quartz crystal microbalance (QCM) biosensing method combining oligonucleotide-functionalized gold nanoparticles (i.e. AuNP probes) used to detect DENV has been established. In the DNA-QCM method, two kinds of specific AuNP probes were linked by the target sequences onto the QCM chip to amplify the detection signal, i.e. oscillatory frequency change ({delta}F) of the QCM sensor. The target sequences amplified from the DENV genome act as a bridge for the layer-by-layer AuNP probes' hybridization in the method. Besides being amplifiers of the detection signal, the specific AuNP probes used in the DNA-QCM method also play the role of verifiers to specifically recognize their target sequences in the detection. The effect of four AuNP sizes on the layer-by-layer hybridization has been evaluated and it is found that 13 nm AuNPs collocated with 13 nm AuNPs showed the best hybridization efficiency. According to the nanoparticle application, the DNA-QCM biosensing method was able to detect dengue viral RNA in virus-contaminated serum as plaque titers being 2 PFU ml{sup -1} and a linear correlation (R{sup 2} = 0.987) of {delta}F versus virus titration from 2 x 10{sup 0} to 2 x 10{sup 6} PFU ml{sup -1} was found. The sensitivity and specificity of the present DNA-QCM method with nanoparticle technology showed it to be comparable to the fluorescent real-time PCR methods. Moreover, the method described herein was shown to not require expensive equipment, was label-free and highly sensitive.

  10. Cu2ZnSnS4 (CZTS) nanoparticle based nontoxic and earth-abundant hybrid pn-junction solar cells.

    Science.gov (United States)

    Saha, Sudip K; Guchhait, Asim; Pal, Amlan J

    2012-06-14

    A heterojunction between a layer of CZTS nanoparticles and a layer of fullerene derivatives forms a pn-junction. We have used such an inorganic-organic hybrid pn-junction device for solar cell applications. As routes to optimize device performance, interdot separation has been reduced by replacing long-chain ligands of the quantum dots with short-chain ligands and thickness of the CZTS layer has been varied. We have shown that the CZTS-fullerene interface could dissociate photogenerated excitons due to the depletion region formed at the pn-junction. From capacitance-voltage characteristics, we have determined the width of the depletion region, and compared it with the parameters of devices based on the components of the heterojunction. The results demonstrate solar cell applications based on nontoxic and earth-abundant materials. PMID:22539133

  11. Hierarchical Self-Assembly of Polyoxometalate-Based Hybrids Driven by Metal Coordination and Electrostatic Interactions: From Discrete Supramolecular Species to Dense Monodisperse Nanoparticles.

    Science.gov (United States)

    Izzet, Guillaume; Abécassis, Benjamin; Brouri, Dalil; Piot, Madeleine; Matt, Benjamin; Serapian, Stefano Artin; Bo, Carles; Proust, Anna

    2016-04-20

    The metal-driven self-assembly processes of a covalent polyoxometalate (POM)-based hybrid bearing remote terpyridine binding sites have been investigated. In a strongly dissociating solvent, a discrete metallomacrocycle, described as a molecular triangle, is formed and characterized by 2D diffusion NMR spectroscopy (DOSY), small-angle X-ray scattering (SAXS), and molecular modeling. In a less dissociating solvent, the primary supramolecular structure, combining negatively charged POMs and cationic metal linkers, further self-assemble through intermolecular electrostatic interactions in a reversible process. The resulting hierarchical assemblies are dense monodisperse nanoparticles composed of ca. 50 POMs that were characterized by SAXS and transmission electron microscopy (TEM). This multiscale organized system directed by metal coordination and electrostatic interactions constitutes a promising step for the future design of POM self-assemblies with controllable structure-directing factors. PMID:27019075

  12. Detection of Helicobacter Pylori Genome with an Optical Biosensor Based on Hybridization of Urease Gene with a Gold Nanoparticles-Labeled Probe

    Science.gov (United States)

    Shahrashoob, M.; Mohsenifar, A.; Tabatabaei, M.; Rahmani-Cherati, T.; Mobaraki, M.; Mota, A.; Shojaei, T. R.

    2016-05-01

    A novel optics-based nanobiosensor for sensitive determination of the Helicobacter pylori genome using a gold nanoparticles (AuNPs)-labeled probe is reported. Two specific thiol-modified capture and signal probes were designed based on a single-stranded complementary DNA (cDNA) region of the urease gene. The capture probe was immobilized on AuNPs, which were previously immobilized on an APTES-activated glass, and the signal probe was conjugated to different AuNPs as well. The presence of the cDNA in the reaction mixture led to the hybridization of the AuNPs-labeled capture probe and the signal probe with the cDNA, and consequently the optical density of the reaction mixture (AuNPs) was reduced proportionally to the cDNA concentration. The limit of detection was measured at 0.5 nM.

  13. Photospintronics: Magnetic Field-Controlled Photoemission and Light-Controlled Spin Transport in Hybrid Chiral Oligopeptide-Nanoparticle Structures.

    Science.gov (United States)

    Mondal, Prakash Chandra; Roy, Partha; Kim, Dokyun; Fullerton, Eric E; Cohen, Hagai; Naaman, Ron

    2016-04-13

    The combination of photonics and spintronics opens new ways to transfer and process information. It is shown here that in systems in which organic molecules and semiconductor nanoparticles are combined, matching these technologies results in interesting new phenomena. We report on light induced and spin-dependent charge transfer process through helical oligopeptide-CdSe nanoparticles' (NPs) architectures deposited on ferromagnetic substrates with small coercive force (∼100-200 Oe). The spin control is achieved by the application of the chirality-induced spin-dependent electron transfer effect and is probed by two different methods: spin-controlled electrochemichemistry and photoluminescence (PL) at room temperature. The injected spin could be controlled by excitation of the nanoparticles. By switching the direction of the magnetic field of the substrate, the PL intensity could be alternated. PMID:27027885

  14. MoS2/reduced graphene oxide hybrid with CdS nanoparticles as a visible light-driven photocatalyst for the reduction of 4-nitrophenol.

    Science.gov (United States)

    Peng, Wen-chao; Chen, Ying; Li, Xiao-yan

    2016-05-15

    Photocatalytic reduction of nitroaromatic compounds to aromatic amines using visible light is an attractive process that utilizes sunlight as the energy source for the chemical conversions. Herewith we synthesized a composite material consisting of CdS nanoparticles grown on the surface of MoS2/reduced graphene oxide (rGO) hybrid as a novel photocatalyst for the reduction of 4-nitrophenol (4-NP). The CdS-MoS2/rGO composite is shown as a high-performance visible light-driven photocatalyst. Even without a noble-metal cocatalyst, the catalyst exhibited a great activity under visible light irradiation for the reduction of 4-NP to much less toxic 4-aminophenol (4-AP) with ammonium formate as the sacrificial agent. Composite CdS-0.03(MoS2/0.01rGO) was found to be the most effective photocatalyst for 4-NP reduction. The high photocatalytic performance is apparently resulted from the synergetic functions of MoS2 and graphene in the composite, i.e. the cocatalysts serve as both the active adsorption sites for 4-NP and electron collectors for the separation of electron-hole pairs generated by CdS nanoparticles. The laboratory results show that the CdS-MoS2/rGO composite is a low-cost and stable photocatalyst for effective reduction and detoxification of nitroaromatic compounds using solar energy.

  15. Effects of Bonding Types and Functional Groups on CO 2 Capture using Novel Multiphase Systems of Liquid-like Nanoparticle Organic Hybrid Materials

    KAUST Repository

    Lin, Kun-Yi Andrew

    2011-08-01

    Novel liquid-like nanoparticle organic hybrid materials (NOHMs) which possess unique features including negligible vapor pressure and a high degree of tunability were synthesized and their physical and chemical properties as well as CO 2 capture capacities were investigated. NOHMs can be classified based on the synthesis methods involving different bonding types, the existence of linkers, and the addition of task-specific functional groups including amines for CO 2 capture. As a canopy of polymeric chains was grafted onto the nanoparticle cores, the thermal stability of the resulting NOHMs was improved. In order to isolate the entropy effect during CO 2 capture, NOHMs were first prepared using polymers that do not contain functional groups with strong chemical affinity toward CO 2. However, it was found that even ether groups on the polymeric canopy contributed to CO 2 capture in NOHMs via Lewis acid-base interactions, although this effect was insignificant compared to the effect of task-specific functional groups such as amine. In all cases, a higher partial pressure of CO 2 was more favorable for CO 2 capture, while a higher temperature caused an adverse effect. Multicyclic CO 2 capture tests confirmed superior recyclability of NOHMs and NOHMs also showed a higher selectivity toward CO 2 over N 2O, O 2 and N 2. © 2011 American Chemical Society.

  16. Effects of bonding types and functional groups on CO2 capture using novel multiphase systems of liquid-like nanoparticle organic hybrid materials.

    Science.gov (United States)

    Lin, Kun-Yi Andrew; Park, Ah-Hyung Alissa

    2011-08-01

    Novel liquid-like nanoparticle organic hybrid materials (NOHMs) which possess unique features including negligible vapor pressure and a high degree of tunability were synthesized and their physical and chemical properties as well as CO(2) capture capacities were investigated. NOHMs can be classified based on the synthesis methods involving different bonding types, the existence of linkers, and the addition of task-specific functional groups including amines for CO(2) capture. As a canopy of polymeric chains was grafted onto the nanoparticle cores, the thermal stability of the resulting NOHMs was improved. In order to isolate the entropy effect during CO(2) capture, NOHMs were first prepared using polymers that do not contain functional groups with strong chemical affinity toward CO(2). However, it was found that even ether groups on the polymeric canopy contributed to CO(2) capture in NOHMs via Lewis acid-base interactions, although this effect was insignificant compared to the effect of task-specific functional groups such as amine. In all cases, a higher partial pressure of CO(2) was more favorable for CO(2) capture, while a higher temperature caused an adverse effect. Multicyclic CO(2) capture tests confirmed superior recyclability of NOHMs and NOHMs also showed a higher selectivity toward CO(2) over N(2)O, O(2) and N(2).

  17. Multifunctional Fe{sub 3}O{sub 4}@C@Ag hybrid nanoparticles: Aqueous solution preparation, characterization and photocatalytic activity

    Energy Technology Data Exchange (ETDEWEB)

    Liang, Hongxia [School of Chemistry and Chemical Engineering, Anhui University, Hefei 230039 (China); Niu, Helin, E-mail: niuhelin@ahu.edu.cn [School of Chemistry and Chemical Engineering, Anhui University, Hefei 230039 (China); Li, Ping; Tao, Zhiyin; Mao, Changjie; Song, Jiming; Zhang, Shengyi [School of Chemistry and Chemical Engineering, Anhui University, Hefei 230039 (China)

    2013-07-15

    Highlights: ► Ag-loaded Fe{sub 3}O{sub 4}@C magnetic-optical bifunctional materials have been investigated. ► The magnetism was studied at the room temperature. ► The photocatalytic activity was evaluated under visible light irradiation. ► Ag-loaded Fe{sub 3}O{sub 4}@C nanocomposites show superior magnetism and photocatalytic activity. ► A simple synthetic process was discussed. - Abstract: The paper describes a kind of multifunctional Fe{sub 3}O{sub 4}@C@Ag hybrid nanoparticles, which can be successfully synthesized using a simple route based on directly adsorption and spontaneous reduction of silver ions onto the surface shell of carbon-coated magnetic nanoparticles. The as-prepared samples have been characterized by transmission electron microscopy (TEM), X-ray powder diffraction (XRD), Fourier transform infrared (FT-IR) spectrum, vibrating sample magnetometer (VSM) and UV–vis spectrum (UV–vis). The Ag nanocrystals loaded on the surface shell of carbon-coated magnetic nanoparticles are nearly spherical with an average diameter of 10 nm. And the carbonaceous polysaccharides shell obtained using an glucose hydrothermal reaction act as a role of a bridge between magnetic Fe{sub 3}O{sub 4} core and noble metallic Ag nanocrystals. The as-prepared samples can be used as an effective catalyst for the photodegradation of organic dyes (neutral red) under the exposure of visible light. Results show that the as-prepared samples have a degradation rate of 93.7% for dyes within 30 min, which indicates their high-efficiency and rapid photocatalytic activity.

  18. Hybrid nanostructures of well-organized arrays of colloidal quantum dots and a self-assembled monolayer of gold nanoparticles for enhanced fluorescence

    Science.gov (United States)

    Liu, Xiaoying; McBride, Sean P.; Jaeger, Heinrich M.; Nealey, Paul F.

    2016-07-01

    Hybrid nanomaterials comprised of well-organized arrays of colloidal semiconductor quantum dots (QDs) in close proximity to metal nanoparticles (NPs) represent an appealing system for high-performance, spectrum-tunable photon sources with controlled photoluminescence. Experimental realization of such materials requires well-defined QD arrays and precisely controlled QD-metal interspacing. This long-standing challenge is tackled through a strategy that synergistically combines lateral confinement and vertical stacking. Lithographically generated nanoscale patterns with tailored surface chemistry confine the QDs into well-organized arrays with high selectivity through chemical pattern directed assembly, while subsequent coating with a monolayer of close-packed Au NPs introduces the plasmonic component for fluorescence enhancement. The results show uniform fluorescence emission in large-area ordered arrays for the fabricated QD structures and demonstrate five-fold fluorescence amplification for red, yellow, and green QDs in the presence of the Au NP monolayer. Encapsulation of QDs with a silica shell is shown to extend the design space for reliable QD/metal coupling with stronger enhancement of 11 times through the tuning of QD-metal spatial separation. This approach provides new opportunities for designing hybrid nanomaterials with tailored array structures and multiple functionalities for applications such as multiplexed optical coding, color display, and quantum transduction.

  19. Hybrid nanostructures of well-organized arrays of colloidal quantum dots and a self-assembled monolayer of gold nanoparticles for enhanced fluorescence

    Science.gov (United States)

    Liu, Xiaoying; McBride, Sean P.; Jaeger, Heinrich M.; Nealey, Paul F.

    2016-07-01

    Hybrid nanomaterials comprised of well-organized arrays of colloidal semiconductor quantum dots (QDs) in close proximity to metal nanoparticles (NPs) represent an appealing system for high-performance, spectrum-tunable photon sources with controlled photoluminescence. Experimental realization of such materials requires well-defined QD arrays and precisely controlled QD–metal interspacing. This long-standing challenge is tackled through a strategy that synergistically combines lateral confinement and vertical stacking. Lithographically generated nanoscale patterns with tailored surface chemistry confine the QDs into well-organized arrays with high selectivity through chemical pattern directed assembly, while subsequent coating with a monolayer of close-packed Au NPs introduces the plasmonic component for fluorescence enhancement. The results show uniform fluorescence emission in large-area ordered arrays for the fabricated QD structures and demonstrate five-fold fluorescence amplification for red, yellow, and green QDs in the presence of the Au NP monolayer. Encapsulation of QDs with a silica shell is shown to extend the design space for reliable QD/metal coupling with stronger enhancement of 11 times through the tuning of QD–metal spatial separation. This approach provides new opportunities for designing hybrid nanomaterials with tailored array structures and multiple functionalities for applications such as multiplexed optical coding, color display, and quantum transduction.

  20. Improved nonlinear optical and optical limiting properties in non-covalent functionalized reduced graphene oxide/silver nanoparticle (NF-RGO/Ag-NPs) hybrid

    Science.gov (United States)

    Sakho, El hadji Mamour; Oluwafemi, Oluwatobi S.; Sreekanth, P.; Philip, Reji; Thomas, Sabu; Kalarikkal, Nandakumar

    2016-08-01

    Nonlinear optical (NLO) response under near infrared (800 nm) and visible (532 nm) laser excitations, of 100 fs (fs) and 5 ns (ns) pulse durations respectively, of reduced graphene oxide (RGO), non-covalent functionalized reduced graphene oxide (NF-RGO) and NF-RGO decorated with various concentration of silver nanoparticles (NF-RGO/Ag-NPs) have been investigated using the Open-aperture Z-Scan technique. For both femtosecond and nanosecond laser excitations, the studied graphene-based materials exhibit good nonlinear optical power limiting properties (OL), with NF-RGO/Ag-NPs sample prepared with 0.1 M AgNO3 showing the best nonlinear optical properties. For the ns regime, the optical limiting threshold decreased from 8.3 J/cm2 in NF-RGO to 4.3 J/cm2 in NF-RGO/Ag-NPs, while at fs regime, the nonlinear absorption coefficient (β) was found to increase with decrease in concentration of Ag-NPs in the hybrid. Two-photon absorption (2 PA) in combination with saturable absorption (SA) in femtosecond regime, and reverse saturable absorption (RSA) along with saturable absorption (SA) in the nanosecond regime, are responsible for the observed nonlinear optical absorption (NLA) behavior in these materials. These findings show that the as-synthesized NF-RGO/Ag-NPs hybrid is a relatively better material for nonlinear optical limiting applications.

  1. Assembly of individual TiO2-C60/porphyrin hybrid nanoparticles for enhancement of photoconversion efficiency

    International Nuclear Information System (INIS)

    Rational organization of porphyrin and C60 on the electrode surface in photovoltaic structures is essential to yield high quantum efficiency. In the present work, individual TiO2 nanoparticles were modified by introducing C60 and porphyrin units on the surface, and then electrophoretically deposited on an ITO/SnO2 electrode. The morphology of the photoactive layer on the electrode was significantly different from that of the layer produced as a result of separate deposition of C60 and porphyrin. The maximum incident photon to current efficiency of the resulting electrode approached 88% at 410 nm, which is the highest value among molecule-based photovoltaic cells reported to date. This indicates that molecular assembly of the C60 and porphyrin units on the individual nanoparticles through strong chemical attachment is a key factor in improving effective electron transfer between the photoactive units and the electrodes.

  2. Photospintronics: Magnetic Field-Controlled Photoemission and Light-Controlled Spin Transport in Hybrid Chiral Oligopeptide-Nanoparticle Structures

    Science.gov (United States)

    2016-01-01

    The combination of photonics and spintronics opens new ways to transfer and process information. It is shown here that in systems in which organic molecules and semiconductor nanoparticles are combined, matching these technologies results in interesting new phenomena. We report on light induced and spin-dependent charge transfer process through helical oligopeptide–CdSe nanoparticles’ (NPs) architectures deposited on ferromagnetic substrates with small coercive force (∼100–200 Oe). The spin control is achieved by the application of the chirality-induced spin-dependent electron transfer effect and is probed by two different methods: spin-controlled electrochemichemistry and photoluminescence (PL) at room temperature. The injected spin could be controlled by excitation of the nanoparticles. By switching the direction of the magnetic field of the substrate, the PL intensity could be alternated. PMID:27027885

  3. Multilayered Si nanoparticle/reduced graphene oxide hybrid as a high-performance lithium-ion battery anode.

    Science.gov (United States)

    Chang, Jingbo; Huang, Xingkang; Zhou, Guihua; Cui, Shumao; Hallac, Peter B; Jiang, Junwei; Hurley, Patrick T; Chen, Junhong

    2014-02-01

    Multilayered Si/RGO anode nanostructures, featuring alternating Si nanoparticle (NP) and RGO layers, good mechanical stability, and high electrical conductivity, allow Si NPs to easily expand between RGO layers, thereby leading to high reversible capacity up to 2300 mAh g(-1) at 0.05 C (120 mA g(-1) ) and 87% capacity retention (up to 630 mAh g(-1) ) at 10 C after 152 cycles.

  4. Photospintronics: Magnetic Field-Controlled Photoemission and Light-Controlled Spin Transport in Hybrid Chiral Oligopeptide-Nanoparticle Structures

    OpenAIRE

    Mondal, Prakash Chandra; Roy, Partha; Kim, Dokyun; Fullerton, Eric E.; Cohen, Hagai; Naaman, Ron

    2016-01-01

    The combination of photonics and spintronics opens new ways to transfer and process information. It is shown here that in systems in which organic molecules and semiconductor nanoparticles are combined, matching these technologies results in interesting new phenomena. We report on light induced and spin-dependent charge transfer process through helical oligopeptide–CdSe nanoparticles’ (NPs) architectures deposited on ferromagnetic substrates with small coercive force (∼100–200 Oe). The spin c...

  5. Hybrid nanocomposite from aniline and CeO2 nanoparticles: Surface protective performance on mild steel in acidic environment

    Science.gov (United States)

    Sasikumar, Y.; Kumar, A. Madhan; Gasem, Zuhair M.; Ebenso, Eno E.

    2015-03-01

    This present work contributes to the development of a new generation of active corrosion inhibitors composed of CeO2 nanoparticles covered with polyaniline that are able to release entrapped nanoparticles in acidic medium. Nanocomposites of aniline and CeO2 nanoparticles have been chemically synthesized by in-situ polymerization. The structural evolutions and morphological characteristics of PANI/CeO2 nanocomposite (PCN) have performed using various techniques such as XRD, IR, XPS, SEM and TEM analysis. It was illustrated from SEM and TEM observation that the PCN has globular particle with core-shell structure. The inhibition properties of synthesized PCN on mild steel (MS) corrosion in 0.5 M HCl were estimated using weight loss and electrochemical techniques. Potentiodynamic polarization results revealed PCN to be a mixed-type inhibitor, while impedance results indicate the adsorption of the PCN film on the MS surface. The inhibition efficiency of PCN was found to increase almost linearly with concentration. Moreover, an increase in the water contact-angle with PCN indicated its adsorption at the MS surface, and ATR-IR, SEM/EDAX and AFM visualization confirmed the formation of a protective film adsorbed on a MS surface. Finally, it was concluded that the PCN is a potential inhibitor for mild steel in HCl medium.

  6. Correlating bulk properties and nanoscale rearrangement during UV-initiated gelation of hybrid nanoparticle/ block copolymer systems

    Science.gov (United States)

    Juggernauth, K. Anne; Seifert, Soenke; Love, Brian

    2013-03-01

    We use rheology and Small Angle X-Ray Scattering (SAXS) to investigate UV initiated gel formation in aqueous dispersions of clay nanoparticles in the presence of poly(ethyleneoxide-b-propyleneoxide-b-ethyleneoxide) block copolymer surfactants (Pluronics®) and small amounts of a photoacid generator (PAG). This material system demonstrates stable liquid-like behavior in the absence of UV but undergoes bulk gelation upon UV exposure. Rheology was used to monitor the bulk properties of a series of samples undergoing UV exposure and confirm bulk gel formation. We further probe nanoparticle rearrangement using time resolved synchrotron SAXS with simultaneous UV exposure. Time dependent SAXS indicate an absence of long range order and crystallinity while changes in the scattering profile are related to short range interparticle interactions leading to a stable or arrested structure. Finally, we compare the time scales for structural rearrangement of nanoparticles with the bulk gelation behavior. Our results show that the kinetics for local structural changes between particles and bulk gelation from UV exposure are strongly correlated.

  7. Nanoscale Organic Hybrid Electrolytes

    KAUST Repository

    Nugent, Jennifer L.

    2010-08-20

    Nanoscale organic hybrid electrolytes are composed of organic-inorganic hybrid nanostructures, each with a metal oxide or metallic nanoparticle core densely grafted with an ion-conducting polyethylene glycol corona - doped with lithium salt. These materials form novel solvent-free hybrid electrolytes that are particle-rich, soft glasses at room temperature; yet manifest high ionic conductivity and good electrochemical stability above 5V. © 2010 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  8. Comprehensive analysis of photonic effects on up-conversion of β-NaYF4:Er3+ nanoparticles in an organic-inorganic hybrid 1D photonic crystal

    Science.gov (United States)

    Hofmann, C. L. M.; Fischer, S.; Reitz, C.; Richards, B. S.; Goldschmidt, J. C.

    2016-04-01

    Upconversion (UC) presents a possibility to exploit sub-bandgap photons for current generation in solar cells by creating one high-energy photon out of at least two lower-energy photons. Photonic structures can enhance UC by two effects: a locally increased irradiance and a modified local density of photon states (LDOS). Bragg stacks are promising photonic structures for this application, because they are straightforward to optimize and overall absorption can be increased by adding more layers. In this work, we present a comprehensive simulation-based analysis of the photonic effects of a Bragg stack on UC luminescence. The investigated organic-inorganic hybrid Bragg stack consists of alternating layers of Poly(methylmethacrylate) (PMMA), containing purpose-built β-NaYF4:25% Er3+ core-shell nanoparticles and titanium dioxide (TiO2). From optical characterization of single thin layers, input parameters for simulations of the photonic effects are generated. The local irradiance enhancement and modulated LDOS are first simulated separately. Subsequently they are coupled in a rate equation model of the upconversion dynamics. Using the integrated model, UC luminescence is maximized by adapting the Bragg stack design. For a Bragg stack of only 5 bilayers, UC luminescence is enhanced by a factor of 3.8 at an incident irradiance of 2000 W/m2. Our results identify the Bragg stack as promising for enhancing UC, especially in the low-irradiance regime, relevant for the application in photovoltaics. Therefore, we experimentally realized optimized Bragg stack designs. The PMMA layers, containing UC nanoparticles, are produced via spin-coating from a toluene based solution. The TiO2 layers are produced by atomic layer deposition from molecular precursors. The reflectance measurements show that the realized Bragg stacks are in good agreement with predictions from simulation.

  9. Development of a simple bioelectrode for the electrochemical detection of hydrogen peroxide using Pichia pastoris catalase immobilized on gold nanoparticle nanotubes and polythiophene hybrid.

    Science.gov (United States)

    Nandini, Seetharamaiah; Nalini, Seetharamaiah; Sanetuntikul, Jakkid; Shanmugam, Sangaraju; Niranjana, Pathappa; Melo, Jose Savio; Suresh, Gurukar Shivappa

    2014-11-21

    In this paper, a simple and innovative electrochemical hydrogen peroxide biosensor has been proposed using catalase (CATpp) derived from Pichia pastoris as bioelectrocatalyst. The model biocomponent was immobilized on gold nanoparticle nanotubes (AuNPNTs) and polythiophene composite using 1-ethyl-3-(3-dimethylaminopropyl)-carbodiimide and N-hydroxysuccinimide (EDC-NHS) coupling reagent. In this present work, we have successfully synthesized gold nanoparticles (AuNPs) by ultrasonic irradiation. The tubular gold nanostructures containing coalesced AuNPs were obtained by sacrificial template synthesis. The assembly of AuNPNTs onto the graphite (Gr) electrode was achieved via S-Au chemisorption. The latter was pre-coated with electropolymerized thiophene (PTh) to enable S groups to bind AuNPNTs. The combination of AuNPNTs-PTh, i.e., an inorganic-organic hybrid, provides a stable enzyme immobilization platform. The physical morphology of the fabricated biosensor Gr/PTh/AuNPNTs/EDC-NHS/CATpp was investigated using scanning electron microscopy and energy-dispersive microscopy. The analytical performance of the bioelectrode was examined using cyclic voltammetry, differential pulse voltammetry and chronoamperometry. Operational parameters such as working potential, pH, and thermal stability of the modified electrode were examined. The beneficial analytical characteristics of the proposed electrode were demonstrated. Our results indicate that the Gr/PTh/AuNPNTs/EDC-NHS/CATpp bioelectrode exhibits a wide linear range from 0.05 mM to 18.5 mM of H2O2, fast response time of 7 s, excellent sensitivity of 26.2 mA mM(-1) cm(-2), good detection limit of 0.12 μM and good Michaelis-Menten constant of 1.4 mM. In addition, the bioelectrode displayed good repeatability, high stability and acceptable reproducibility, which can be attributed to the AuNPNTs-PTh composite that provides a biocompatible micro-environment. PMID:25208248

  10. Co-encapsulation of multi-lipids and polymers enhances the performance of vancomycin in lipid-polymer hybrid nanoparticles: In vitro and in silico studies.

    Science.gov (United States)

    Seedat, Nasreen; Kalhapure, Rahul S; Mocktar, Chunderika; Vepuri, Suresh; Jadhav, Mahantesh; Soliman, Mahmoud; Govender, Thirumala

    2016-04-01

    Nano-drug delivery systems are being widely explored to overcome the challenges with existing antibiotics to treat bacterial infections [1]. Lipid-polymer hybrid nanoparticles (LPNs) display unique advantages of both liposomes and polymeric nanoparticles while excluding some of their limitations, particularly the structural integrity of the polymeric particles and the biomimetic properties of the liposome [1]. The use of helper lipids and polymers in LPNs has not been investigated, but has shown potential in other nano-drug delivery systems to improve drug encapsulation, antibacterial activity and drug release. Therefore, LPNs using co-excipients were prepared using vancomycin (VCM), glyceryl triplamitate and Eudragit RS100 as the drug, lipid and polymer respectively. Oleic acid (OA), Chitosan (CHT) and Sodium alginate (ALG) were explored as co-excipients. Results indicated rod-shaped LPNs with suitable size, PDI and zeta potential, while encapsulation efficiency (%EE) increased from 27.8% to 41.5%, 54.3% and 69.3% with the addition of OA, CHT and ALG respectively. Drug release indicated that VCM-CHT had the best performance in sustained drug release of 36.1 ± 5.35% after 24h. The EE and drug release were further corroborated by in silico and release kinetics data. In vitro antibacterial studies of all formulations exhibited better activity against bare VCM and sustained activity up to day 5 against both Staphylococcus aureus and MRSA, with VCM-OA and VCM-CHT showing better activity against MRSA. Therefore, this LPN proves to be a promising system for delivery of VCM as well as other antibiotics.

  11. Plasmon resonance hybridization in self-assembled copper nanoparticle clusters: efficient and precise localization of surface plasmon resonance (LSPR) sensing based on Fano resonances.

    Science.gov (United States)

    Ahmadivand, Arash; Pala, Nezih

    2015-01-01

    In this work, we have investigated the hybridization of plasmon resonance modes in completely copper (Cu)-based subwavelength nanoparticle clusters from simple symmetric dimers to complex asymmetric self-assembled structures. The quality of apparent bonding and antibonding plasmon resonance modes for all of the clusters has been studied, and we examined the spectral response of each one of the proposed configurations numerically using the finite-difference time domain (FDTD) method. The effect of the geometric sizes of nanoparticles used and substrate refractive index on the cross-sectional profiles of each of the studied structures has been calculated and drawn. We proved that Fano-like resonance can be formed in Cu-based heptamer clusters as in analogous noble metallic particles (e.g., Au and Ag) by determining the coupling strength and interference between sub-radiant and super-radiant resonance modes. Employing certain Cu nanodiscs in designing an octamer structure, we measured the quality of the Fano dip formation along the scattering diagram. Accurate tuning of the geometric sizes for the Cu-based octamer yields an opportunity to observe isotropic, deep, and narrow Fano minima along the scattering profile that are in comparable condition with the response of other plasmonic metallic substances. Immersing investigated final Cu-based octamer in various liquids with different refractive indices, we determined the sensing accuracy of the cluster based on the performance of the Fano dip. Plotting a linear diagram of plasmon energy differences over the refractive index variations as a figure of merit (FoM), which we have quantified as 13.25. With this method, the precision of the completely Cu-based octamer is verified numerically using the FDTD tool. This study paves the way toward the use of Cu as an efficient, low-cost, and complementary metal-oxide semiconductor (CMOS)-compatible plasmonic material with optical properties that are similar to analogous plasmonic

  12. cRGD-directed, NIR-responsive and robust AuNR/PEG-PCL hybrid nanoparticles for targeted chemotherapy of glioblastoma in vivo.

    Science.gov (United States)

    Zhong, Yinan; Wang, Chao; Cheng, Ru; Cheng, Liang; Meng, Fenghua; Liu, Zhuang; Zhong, Zhiyuan

    2014-12-10

    cRGD-directed, NIR-responsive and robust AuNR/PEG-PCL hybrid nanoparticles (cRGD-HNs) were designed and developed for targeted chemotherapy of human glioma xenografts in mice. As expected, cRGD-HNs had excellent colloidal stability. The in vitro release studies showed that drug release from DOX-loaded cRGD-HNs (cRGD-HN-DOX) was minimal under physiological conditions but markedly accelerated upon NIR irradiation at a low power density of 0.2 W/cm2, due to photothermally induced phase transition of PCL regime. MTT assays showed that the antitumor activity of cRGD-HN-DOX in αvβ3 integrin over-expressed human glioblastoma U87MG cells was greatly boosted by mild NIR irradiation, which was significantly more potent than non-targeting HN-DOX counterpart under otherwise the same conditions and was comparable or superior to free DOX, supporting receptor-mediated endocytosis mechanism. The in vivo pharmacokinetics studies showed that cRGD-HN-DOX had much longer circulation time than free DOX. The in vivo imaging and biodistribution studies revealed that cRGD-HN-DOX could actively target human U87MG glioma xenograft in nude mice. The therapeutic studies in human U87MG glioma xenografts exhibited that cRGD-HN-DOX in combination with NIR irradiation completely inhibited tumor growth and possessed much lower side effects than free DOX. The Kaplan-Meier survival curves showed that all mice treated with cRGD-HN-DOX plus NIR irradiation survived over an experimental period of 48 days while control groups treated with PBS, cRGD-HN-DOX, cRGD-HNs with NIR irradiation, free DOX, or HN-DOX with NIR irradiation (non-targeting control) had short life spans of 15-40 days. Ligand-directed AuNR/PEG-PCL hybrid nanoparticles with evident tumor-targetability as well as superior spatiotemporal and rate control over drug release have emerged as an appealing platform for cancer chemotherapy in vivo.

  13. A simple approach to obtain hybrid Au-loaded polymeric nanoparticles with a tunable metal load† †Electronic supplementary information (ESI) available. See DOI: 10.1039/c5nr06850a Click here for additional data file.

    Science.gov (United States)

    Luque-Michel, Edurne; Larrea, Ane; Lahuerta, Celia; Imbuluzqueta, Edurne; Arruebo, Manuel; Santamaría, Jesús

    2016-01-01

    A new strategy to nanoengineer multi-functional polymer–metal hybrid nanostructures is reported. By using this protocol the hurdles of most of the current developments concerning covalent and non-covalent attachment of polymers to preformed inorganic nanoparticles (NPs) are overcome. The strategy is based on the in situ reduction of metal precursors using the polymeric nanoparticle as a nanoreactor. Gold nanoparticles and poly(dl-lactic-co-glycolic acid), PLGA, are located in the core and shell, respectively. This novel technique enables the production of PLGA NPs smaller than 200 nm that bear either a single encapsulated Au NP or several smaller NPs with tunable sizes and a 100% loading efficiency. In situ reduction of Au ions inside the polymeric NPs was achieved on demand by using heat to activate the reductive effect of citrate ions. In addition, we show that the loading of the resulting Au NPs inside the PLGA NPs is highly dependent on the surfactant used. Electron microscopy, laser irradiation, UV-Vis and fluorescence spectroscopy characterization techniques confirm the location of Au nanoparticles. These promising results indicate that these hybrid nanomaterials could be used in theranostic applications or as contrast agents in dark-field imaging and computed tomography. PMID:26612770

  14. Simultaneous determination of epinephrine and dopamine by electrochemical reduction on the hybrid material SiO₂/graphene oxide decorated with Ag nanoparticles.

    Science.gov (United States)

    Cincotto, Fernando H; Canevari, Thiago C; Campos, Anderson M; Landers, Richard; Machado, Sérgio A S

    2014-09-21

    This paper describes the synthesis, characterization and applications of a new hybrid material composed of mesoporous silica (SiO2) modified with graphene oxide (GO), SiO2/GO, obtained by the sol-gel process using HF as the catalyst. The hybrid material, SiO2/GO, was decorated with silver nanoparticles (AgNPs) with a size of less than 20 nanometres, prepared directly on the surface of the material using N,N-dimethylformamide (DMF) as the reducing agent. The resulting material was designated as AgNP/SiO2/GO. The Ag/SiO2/GO material was characterized by X-ray photoelectron spectroscopy (XPS), scanning electron microscopy (SEM), energy-dispersive X-ray (EDX) and high-resolution transmission electron microscopy (HR-TEM). A glassy carbon electrode modified with AgNP/SiO2/GO was used in the development of a sensitive electrochemical sensor for the simultaneous determination of epinephrine and dopamine employing electrocatalytic reduction using squarewave voltammetry. Well-defined and separate reduction peaks were observed in PBS buffer at pH 7. No significant interference was seen for primarily biological interferents such as uric acid and ascorbic acid in the detection of dopamine and epinephrine. Our study demonstrated that the resultant AgNP/SiO2/GO-modified electrode is highly sensitive for the simultaneous determination of dopamine and epinephrine, with the limits of detection being 0.26 and 0.27 μmol L(-1), respectively. The AgNP/SiO2/GO-modified electrode is highly selective and can be used to detect dopamine and epinephrine in a human urine sample.

  15. Hybrid biocomposite with a tunable antibacterial activity and bioactivity based on RF magnetron sputter deposited coating and silver nanoparticles

    Energy Technology Data Exchange (ETDEWEB)

    Ivanova, A.A. [Department of Theoretical and Experimental Physics, Center of Technology, National Research Tomsk Polytechnic University, 634050 Tomsk (Russian Federation); Surmenev, R.A., E-mail: rsurmenev@gmail.com [Department of Theoretical and Experimental Physics, Center of Technology, National Research Tomsk Polytechnic University, 634050 Tomsk (Russian Federation); Fraunhofer Institute for Interfacial Engineering and Biotechnology IGB, 70569 Stuttgart (Germany); Surmeneva, M.A.; Mukhametkaliyev, T. [Department of Theoretical and Experimental Physics, Center of Technology, National Research Tomsk Polytechnic University, 634050 Tomsk (Russian Federation); Loza, K.; Prymak, O.; Epple, M. [Inorganic Chemistry and Center for Nanointegration Duisburg-Essen (CeNIDE), University of Duisburg-Essen, 45117 Essen (Germany)

    2015-02-28

    Highlights: • A biocomposite of hydroxyapatite film and silver nanoparticles (AgNPs) was tested. • The concentration of the released silver in phosphate or acetate buffer was studied. • The concentration and release rate of AgNPs can be controlled in a tailored manner. - Abstract: In this work, we describe fabrication techniques used to prepare a multifunctional biocomposite based on a hydroxyapatite (HA) coating and silver nanoparticles (AgNPs). AgNPs synthesized by a wet chemical reduction method were deposited on Ti substrates using a dripping/drying method followed by deposition of calcium phosphate (CaP) coating via radio-frequency (RF) magnetron sputter-deposition. The negatively charged silver nanoparticles (zeta potential −21 mV) have a spherical shape with a metallic core diameter of 50 ± 20 nm. The HA coating was deposited as a dense nanocrystalline film over a surface of AgNPs. The RF-magnetron sputter deposition of HA films on the AgNPs layer did not affect the initial content of AgNPs on the substrate surface as well as NPs size and shape. SEM cross-sectional images taken using the backscattering mode revealed a homogeneous layer of AgNPs under the CaP layer. The diffraction patterns from the coatings revealed reflexes of crystalline HA and silver. The concentration of Ag ions released from the biocomposites after 7 days of immersion in phosphate and acetate buffers was estimated. The obtained results revealed that the amount of silver in the solutions was 0.27 ± 0.02 μg mL{sup −1} and 0.54 ± 0.02 μg mL{sup −1} for the phosphate and acetate buffers, respectively, which corresponded well with the minimum inhibitory concentration range known for silver ions in literature. Thus, this work establishes a new route to prepare a biocompatible layer using embedded AgNPs to achieve a local antibacterial effect.

  16. Effect of water on the physical properties and carbon dioxide capture capacities of liquid-like Nanoparticle Organic Hybrid Materials and their corresponding polymers

    KAUST Repository

    Petit, Camille

    2013-10-01

    Binary systems composed of liquid-like Nanoparticle Organic Hybrid Materials (NOHMs) and the secondary fluid (i.e., water) were prepared, and their thermal stabilities, densities, viscosities, and CO2 absorption capacities were investigated. Recent work has suggested NOHMs as an alternative CO2 capture media with interesting chemical and physical tunability. Anhydrous CO2 capture solvents often degrade when they are exposed to water, while flue gas generally contains about 8-16% water. Thus, this study was conducted to investigate the effect of water on the NOHMs\\' properties relevant to CO2 capture as well as the chemical and thermal stabilities of H2O-loaded NOHMs. It was found that water acted as an antisolvent of NOHMs, and therefore, caused a decreased CO2 capture capacity. On the other hand, the results indicated that while water did not affect the NOHMs\\' thermal stability, it significantly helped lowering their density and viscosity. In order to investigate the effect of intermolecular interactions among two fluids on the density and viscosity, the excess volumes and viscosity deviations were calculated and correlated with Redlich-Kister equations. The trends revealed the existence of strong intermolecular interactions between water molecules and the poly(ethlyne glycol) component of NOHMs, which may have caused the drastic decrease in the NOHMs\\' viscosity with the addition of water. © 2013 Elsevier Inc.

  17. Self-Volatilization Approach to Mesoporous Carbon Nanotube/Silver Nanoparticle Hybrids: The Role of Silver in Boosting Li Ion Storage.

    Science.gov (United States)

    Jiang, Hao; Zhang, Haoxuan; Fu, Yao; Guo, Shaojun; Hu, Yanjie; Zhang, Ling; Liu, Yu; Liu, Honglai; Li, Chunzhong

    2016-01-26

    One of the biggest challenging issues of carbon nanomaterials for Li ion batteries (LIBs) is that they show low initial Coulombic efficiency (CE), leading to a limited specific capacity. Herein, we demonstrate a simple template self-volatilization strategy for in situ synthesis of mesoporous carbon nanotube/Ag nanoparticle (NP) hybrids (Ag-MCNTs) to boost the LIBs' performance. The key concept of Ag-MCNTs for enhancing LIBs is that a small trace of Ag NPs on MCNTS can greatly restrict the formation of a thicker solid electrolyte interphase film, which has been well verified by both transmission electron microscopy results and quantum density functional theory calculations, leading to the highest initial CE in all the reported carbon nanomaterials. This uncovered property of Ag NPs from Ag-MCNTs makes them exhibit a very high reversible capacity of 1637 mAh g(-1) after 400 discharge/charge cycles at 100 mA g(-1), approximately 5 times higher than the theoretical value of a graphite anode (372 mAh g(-1)), excellent rate capability, and long cycle life.

  18. Identification of human DNA in forensic evidence by loop-mediated isothermal amplification combined with a colorimetric gold nanoparticle hybridization probe.

    Science.gov (United States)

    Watthanapanpituck, Khanistha; Kiatpathomchai, Wansika; Chu, Eric; Panvisavas, Nathinee

    2014-11-01

    A DNA test based on loop-mediated isothermal amplification (LAMP) and colorimetric gold nanoparticle (AuNP) hybridization probe to detect the presence of human DNA in forensic evidence was developed. The LAMP primer set targeted eight regions of the human cytochrome b, and its specificity was verified against the DNA of 11 animal species, which included animals closely related to humans, such as chimpanzee and orangutan. By using the AuNP probe, sequence-specific LAMP product could be detected and the test result could be visualized through the change in color. The limit of detection was demonstrated with reproducibility to be as low as 718 fg of genomic DNA, which is equivalent to approximately 100 plasmid DNA copies containing the cytochrome b DNA target region. A simple DNA extraction method for the commonly found forensic biological samples was also devised to streamline the test process. This LAMP-AuNP human DNA test showed to be a robust, specific, and cost-effective tool for the forensic identification of human specimens without requiring sophisticated laboratory instruments.

  19. Water-dispersable hybrid Au-Pd nanoparticles as catalysts in ethanol oxidation, aqueous phase Suzuki-Miyaura and Heck reactions

    KAUST Repository

    Song, HyonMin

    2012-01-01

    The catalytic activities of water-dispersable Au@Pd core-shell nanoparticles (NPs) and Au-Pd alloy NPs were examined. There is growing interest in Au-Pd hybridized NPs in a supported matrix or non-supported forms as catalysts in various reactions that are not limited to conventional Pd-related reactions. Four different Au@Pd core-shell NPs in this study were prepared at room temperature with help from the emulsion phase surrounding the Au core NPs. Au-Pd alloy NPs were prepared over 90 °C, and underwent phase transfer to aqueous medium for their catalytic use. Au@Pd core-shell NPs show catalytic activity in ethanol oxidation reactions as electrocatalysts, and both core-shell and alloy NPs are good to excellent catalysts in various Suzuki-Miyaura and Heck reactions as heterogeneous catalysts. Specifically, Au@Pd core-shell NPs with sharp branched arms show the highest yield in the reactions tested in this study. A relatively small amount (0.25 mol%) was used throughout the catalytic reactions. © 2012 The Royal Society of Chemistry.

  20. Identification of human DNA in forensic evidence by loop-mediated isothermal amplification combined with a colorimetric gold nanoparticle hybridization probe.

    Science.gov (United States)

    Watthanapanpituck, Khanistha; Kiatpathomchai, Wansika; Chu, Eric; Panvisavas, Nathinee

    2014-11-01

    A DNA test based on loop-mediated isothermal amplification (LAMP) and colorimetric gold nanoparticle (AuNP) hybridization probe to detect the presence of human DNA in forensic evidence was developed. The LAMP primer set targeted eight regions of the human cytochrome b, and its specificity was verified against the DNA of 11 animal species, which included animals closely related to humans, such as chimpanzee and orangutan. By using the AuNP probe, sequence-specific LAMP product could be detected and the test result could be visualized through the change in color. The limit of detection was demonstrated with reproducibility to be as low as 718 fg of genomic DNA, which is equivalent to approximately 100 plasmid DNA copies containing the cytochrome b DNA target region. A simple DNA extraction method for the commonly found forensic biological samples was also devised to streamline the test process. This LAMP-AuNP human DNA test showed to be a robust, specific, and cost-effective tool for the forensic identification of human specimens without requiring sophisticated laboratory instruments. PMID:24827529

  1. Enzyme-free fluorescent biosensor for the detection of DNA based on core-shell Fe3O4 polydopamine nanoparticles and hybridization chain reaction amplification.

    Science.gov (United States)

    Li, Na; Hao, Xia; Kang, Bei Hua; Xu, Zhen; Shi, Yan; Li, Nian Bing; Luo, Hong Qun

    2016-03-15

    A novel, highly sensitive assay for quantitative determination of DNA is developed based on hybridization chain reaction (HCR) amplification and the separation via core-shell Fe3O4 polydopamine nanoparticles (Fe3O4@PDA NPs). In this assay, two hairpin probes are designed, one of which is labeled with a 6-carboxyfluorescein (FAM). Without target DNA, auxiliary hairpin probes are stable in solution. However, when target DNA is present, the HCR between the two hairpins is triggered. The HCR products have sticky ends of 24 nt, which are much longer than the length of sticky ends of auxiliary hairpins (6 nt) and make the adsorption much easier by Fe3O4@PDA NPs. With the addition of Fe3O4@PDA NPs, HCR products could be adsorbed because of the strong interaction between their sticky ends and Fe3O4@PDA NPs. As a result, supernatant of the solution with target DNA emits weak fluorescence after separation by magnet, which is much lower than that of the blank solution. The detection limit of the proposed method is as low as 0.05 nM. And the sensing method exhibits high selectivity for the determination between perfectly complementary sequence and target with single base-pair mismatch. Importantly, the application of the sensor for DNA detection in human serum shows that the proposed method works well for biological samples.

  2. An injectable hybrid nanoparticle-in-oil-in-water submicron emulsion for improved delivery of poorly soluble drugs

    Science.gov (United States)

    Wang, Shuo; Wang, Hua; Liang, Wenquan; Huang, Yongzhuo

    2012-04-01

    Poor drugability problems are commonly seen in a class of chemical entities with poor solubility in water and oil, and moreover, physicochemical instability of these compounds poses extra challenges in design of dosage forms. Such problems contribute a significant high failure rate in new drug development. A hybrid nanoparicle-in-oil-in-water (N/O/W) submicron emulsion was proposed for improved delivery of poorly soluble and unstable drugs (e.g., dihydroartemisinin (DHA)). DHA is known for its potent antimalarial effect and antitumor activity. However, its insolubility and instability impose big challenges for formulations, and so far, no injectable dosage forms are clinically available yet. Therefore, an injectable DHA N/O/W system was developed. Unlike other widely-explored systems (e.g., liposomes, micelles, and emulsions), in which low drug load and only short-term storage are often found, the hybrid submicron emulsion possesses three-fold higher drug-loading capacity than the conventional O/W emulsion. Of note, it can be manufactured into a freeze-drying form and can render its storage up to 6 months even in room temperature. The in vivo studies demonstrated that the PK profiles were significantly improved, and this injectable system was effective in suppressing tumor growth. The strategy provides a useful solution to effective delivery of such a class of drugs.

  3. Visual detection of cancer cells by colorimetric aptasensor based on aggregation of gold nanoparticles induced by DNA hybridization.

    Science.gov (United States)

    Borghei, Yasaman-Sadat; Hosseini, Morteza; Dadmehr, Mehdi; Hosseinkhani, Saman; Ganjali, Mohammad Reza; Sheikhnejad, Reza

    2016-01-21

    A simple but highly sensitive colorimetric method was developed to detect cancer cells based on aptamer-cell interaction. Cancer cells were able to capture nucleolin aptamers (AS 1411) through affinity interaction between AS 1411 and nucleolin receptors that are over expressed in cancer cells, The specific binding of AS 1411 to the target cells triggered the removal of aptamers from the solution. Therefore no aptamer remained in the solution to hybridize with complementary ssDNA-AuNP probes as a result the solution color is red. In the absence of target cells or the presence of normal cells, ssDNA-AuNP probes and aptamers were coexisted in solution and the aptamers assembled DNA-AuNPs, produced a purple solution. UV-vis spectrometry demonstrated that this hybridization-based method exhibited selective colorimetric responses to the presence or absence of target cells, which is detectable with naked eye. The linear response for MCF-7 cells in a concentration range from 10 to 10(5) cells was obtained with a detection limit of 10 cells. The proposed method could be extended to detect other cells and showed potential applications in cancer cell detection and early cancer diagnosis. PMID:26724767

  4. Simplifying the growth of hybrid single-crystals by using nanoparticle precursors: the case of AgI

    Science.gov (United States)

    Xu, Biao; Wang, Ruji; Wang, Xun

    2012-03-01

    We report the synthesis of a series of AAgmIn single-crystals within 24 h, at room temperature, utilizing AgI nanoparticles (NPs) as the precursor. The AgI NPs impart high reactivity under mild conditions and favor the growth kinetics. 0D, 1D and 2D iodoargentate crystals can be obtained. This work represents the first application of NPs in the field of organo-metal-halide crystals and will inspire the design of other AMmXn crystals.We report the synthesis of a series of AAgmIn single-crystals within 24 h, at room temperature, utilizing AgI nanoparticles (NPs) as the precursor. The AgI NPs impart high reactivity under mild conditions and favor the growth kinetics. 0D, 1D and 2D iodoargentate crystals can be obtained. This work represents the first application of NPs in the field of organo-metal-halide crystals and will inspire the design of other AMmXn crystals. Electronic supplementary information (ESI) available: XPS spectra of AgI NPs, schematic representation of the formation process of [Ag4I8]4- in 2, UV-Vis spectra of the DTMA-Ag-I clusters, analysis of force balance of a crystal at the interface between H2O and CH2Cl2 and crystal structure depiction of 1-4. CIF files of 1-4 are also provided. CCDC reference numbers 863848, 863849, 863850 and 863851. For ESI and crystallographic data in CIF or other electronic format see DOI: 10.1039/c2nr30139c

  5. Spoof Plasmon Hybridization

    CERN Document Server

    Zhang, Jingjing; Luo, Yu; Shen, Xiaopeng; Maier, Stefan A; Cui, Tie Jun

    2016-01-01

    Plasmon hybridization between closely spaced nanoparticles yields new hybrid modes not found in individual constituents, allowing for the engineering of resonance properties and field enhancement capabilities of metallic nanostructure. Experimental verifications of plasmon hybridization have been thus far mostly limited to optical frequencies, as metals cannot support surface plasmons at longer wavelengths. Here, we introduce the concept of 'spoof plasmon hybridization' in highly conductive metal structures and investigate experimentally the interaction of localized surface plasmon resonances (LSPR) in adjacent metal disks corrugated with subwavelength spiral patterns. We show that the hybridization results in the splitting of spoof plasmon modes into bonding and antibonding resonances analogous to molecular orbital rule and plasmonic hybridization in optical spectrum. These hybrid modes can be manipulated to produce enormous field enhancements (larger than 5000) by tuning the separation between disks or alte...

  6. Threshold voltage manipulation of ZnO-graphene oxide hybrid thin film transistors via Au nanoparticles doping

    Science.gov (United States)

    Song, Wooseok; Kim, Ki Woong; Kim, Seong Jun; Min, Bok Ki; Rang Lim, Yi; Myung, Sung; Lee, Sun Sook; Lim, Jongsun; An, Ki-Seok

    2015-12-01

    In order to fabricate a complementary inverter, precise control of the threshold voltages for n-type semiconductor based thin film transistors (TFTs) is highly required. Here we provided a facile methodology for controlling the threshold voltage of ZnO-based TFTs. Chemically-derived graphene oxide (GO) and Au-decorated GO (Au-GO) flakes were hybridized with solution-processed ZnO thin films to control electron injection determined by the workfunction difference between ZnO and GO or Au-GO. As a result, the threshold voltages for the ZnO, GO/ZnO, and Au-GO/ZnO TFTs were 24 ± 3 V, -11 ± 4 V, and 63 ± 5 V, respectively, which determine depletion or enhancement mode TFTs without any significant change in the field effect mobility and on/off ratio.

  7. Iron Carbide Nanoparticles Encapsulated in Mesoporous Fe-N-Doped Graphene-Like Carbon Hybrids as Efficient Bifunctional Oxygen Electrocatalysts.

    Science.gov (United States)

    Jiang, Hongliang; Yao, Yifan; Zhu, Yihua; Liu, Yanyan; Su, Yunhe; Yang, Xiaoling; Li, Chunzhong

    2015-09-30

    It is highly crucial and challenging to develop bifunctional oxygen electrocatalysts for oxygen reduction reactions (ORRs) and oxygen evolution reactions (OERs) in rechargeable metal-air batteries and unitized regenerative fuel cells (URFCs). Herein, a facile and cost-effective strategy is developed to prepare mesoporous Fe-N-doped graphene-like carbon architectures with uniform Fe3C nanoparticles encapsulated in graphitic layers (Fe3C@NG) via a one-step solid-state thermal reaction. The optimized Fe3C@NG800-0.2 catalyst shows comparable ORR activity with the state-of-the-art Pt/C catalyst and OER activity with the benchmarking RuO2 catalyst. The oxygen electrode activity parameter ΔE (the criteria for judging the overall catalytic activity of bifunctional electrocatalysts) value for Fe3C@NG800-0.2 is 0.780 V, which surpasses those of Pt/C and RuO2 catalysts as well as those of most nonprecious metal catalysts. Significantly, excellent long-term catalytic durability holds great promise in fields of rechargeable metal-air batteries and URFCs. PMID:26371772

  8. Label-Free MicroRNA Detection Based on Fluorescence Quenching of Gold Nanoparticles with a Competitive Hybridization.

    Science.gov (United States)

    Wang, Wei; Kong, Tao; Zhang, Dong; Zhang, Jinan; Cheng, Guosheng

    2015-11-01

    MicroRNAs (miRNAs), critical biomarkers of acute and chronic diseases, play key regulatory roles in many biological processes. As a result, there is great demand for robust assay platforms to enable an accurate and efficient detection of low-level miRNAs in complex biological samples. In this work, a label-free and Au nanoparticles (NPs) quenching-based competition assay system was developed. In the designed system, Au NPs with diameter sizes of 10 and 20 nm displayed fluorescence quenching efficiencies of 84% and 82% for Cy3 dye on slide surface, whereas the quenching efficiency of commercial BHQ2 quencher was roughly 50%. Assay conditions were optimized for miRNA-205 detection. A limit of detection of 3.8 pM and a detection range covering from 3.8 pM to 10 nM were achieved. Furthermore, the proposed system was capable of specifically discriminating miRNAs with slight variations in their nucleotide sequence and was also qualified for assessing miRNA levels in human serum. Our strategy has the potential to provide new perspectives in profiling the pattern of miRNA expression and biomedical utilizations.

  9. Hybrid polymer-CdS solar cell active layers formed by in situ growth of CdS nanoparticles

    International Nuclear Information System (INIS)

    The integration of semiconductor nanoparticles (NPs) into a polymeric matrix has the potential to enhance the performance of polymer-based solar cells taking advantage of the physical properties of NPs and polymers. We synthesize a new class of CdS-NPs-based active layer employing a low-cost and low temperature route compatible with large-scale device manufacturing. Our approach is based on the controlled in situ thermal decomposition of a cadmium thiolate precursor in poly(3-hexylthiophene) (P3HT). The casted P3HT:precursor solid foils were heated up from 200 to 300 °C to allow the precursor decomposition and the CdS-NP formation within the polymer matrix. The CdS-NP growth was controlled by varying the annealing temperature. The polymer:precursor weight ratio was also varied to investigate the effects of increasing the NP volume fraction on the solar cell performances. The optical properties were studied by using UV–Vis absorption and photoluminescence (PL) spectroscopy at room temperature. To investigate the photocurrent response of P3HT:CdS nanocomposites, ITO/P3HT:CdS/Al solar cell devices were realized. We measured the external quantum efficiency (EQE) as a function of the wavelength. The photovoltaic response of the devices containing CdS-NPs showed a variation compared with the devices with P3HT only. By changing the annealing temperature the EQE is enhanced in the 400–600 nm spectral region. By increasing the NPs volume fraction remarkable changes in the EQE spectra were observed. The data are discussed also in relation to morphological features of the interfaces studied by Focused Ion Beam technique.

  10. Magnetically aligned iron oxide/gold nanoparticle-decorated carbon nanotube hybrid structure as a humidity sensor.

    Science.gov (United States)

    Lee, Jaewook; Mulmi, Suresh; Thangadurai, Venkataraman; Park, Simon S

    2015-07-22

    Functionalized carbon nanotubes (f-CNTs), particularly CNTs decorated with nanoparticles (NPs), are of great interest because of their synergic effects, such as surface-enhanced Raman scattering, plasmonic resonance energy transfer, magnetoplasmonic, magnetoelectric, and magnetooptical effects. In general, research has focused on a single type of NP, such as a metal or metal oxide, that has been modified on a CNT surface. In this study, however, a new strategy is introduced for the decoration of two different NP types on CNTs. In order to improve the functionality of modified CNTs, we successfully prepared binary NP-decorated CNTs, namely, iron oxide/gold (Au) NP-decorated CNTs (IA-CNTs), which were created through two simple reactions in deionized water, without high temperature, high pressure, or harsh reducing agents. The physicochemical properties of IA-CNTs were characterized by ultraviolet/visible spectroscopy, Fourier transform infrared spectroscopy, a superconducting quantum interference device, scanning electron microscopy, and transmission electron microscopy. In this study, IA-CNTs were utilized to detect humidity. Magnetic IA-CNTs were aligned on interdigitated platinum electrodes under external magnetic fields to create a humidity-sensing channel, and its electrical conductivity was monitored. As the humidity increased, the electrical resistance of the sensor also increased. In comparison with various gases, for example, H2, O2, CO, CO2, SO2, and dry air, the IA-CNT-based humidity sensor exhibited high-selectivity performances. IA-CNTs also responded to heavy water (D2O), and it was established that the humidity detection mechanism had D2O-sensing capabilities. Further, the humidity from human out-breathing was also successfully detected by this system. In conclusion, these unique IA-CNTs exhibited potential application as gas detection materials. PMID:26112318

  11. Development and in vitro evaluation of core-shell type lipid-polymer hybrid nanoparticles for the delivery of erlotinib in non-small cell lung cancer.

    Science.gov (United States)

    Mandal, Bivash; Mittal, Nivesh K; Balabathula, Pavan; Thoma, Laura A; Wood, George C

    2016-01-01

    Core-shell type lipid-polymer hybrid nanoparticles (CSLPHNPs) have emerged as a multifunctional drug delivery platform. The delivery system combines mechanical advantages of polymeric core and biomimetic advantages of the phospholipid shell into a single platform. We report the development of CSLPHNPs composed of the lipid monolayer shell and the biodegradable polymeric core for the delivery of erlotinib, an anticancer drug, clinically used to treat non-small cell lung cancer (NSCLC). Erlotinib loaded CSLPHNPs were prepared by previously reported single-step sonication method using polycaprolactone (PCL) as the biodegradable polymeric core and phospholipid-shell composed of hydrogenated soy phosphatidylcholine (HSPC) and 1,2-distearoyl-sn-glycero-3-phosphoethanolamine-N-[methoxy(polyethylene glycol)-2000 (DSPE-PEG2000). Erlotinib loaded CSLPHNPs were characterized for physicochemical properties including mean particle size, polydispersity index (PDI), zeta potential, morphology, thermal and infrared spectral analysis, drug loading, in vitro drug release, in vitro serum stability, and storage stability. The effect of critical formulation and process variables on two critical quality attributes (mean particle size and drug entrapment efficiency) of erlotinib loaded CSLPHNPs was studied and optimized. In addition, in vitro cellular uptake, luminescent cell viability assay and colony formation assay were performed to evaluate efficacy of erlotinib loaded CSLPHNPs in A549 cells, a human lung adenocarcinoma cell line. Optimized erlotinib loaded CSLPHNPs were prepared with mean particle size of about 170nm, PDI<0.2, drug entrapment efficiency of about 66% with good serum and storage stability. The evaluation of in vitro cellular efficacy results indicated enhanced uptake and efficacy of erlotinib loaded CSLPHNPs compared to erlotinib solution in A549 cells. Therefore, CSLPHNPs could be a potential delivery system for erlotinib in the therapy of NSCLC.

  12. Magnetic/NIR-responsive drug carrier, multicolor cell imaging, and enhanced photothermal therapy of gold capped magnetite-fluorescent carbon hybrid nanoparticles

    Science.gov (United States)

    Wang, Hui; Cao, Guixin; Gai, Zheng; Hong, Kunlun; Banerjee, Probal; Zhou, Shuiqin

    2015-04-01

    This paper reports a type of multifunctional hybrid nanoparticle (NP) composed of gold nanocrystals coated on and/or embedded in a magnetite-fluorescent porous carbon core-shell NP template (Fe3O4@PC-CDs-Au) for biomedical applications, including magnetic/NIR-responsive drug release, multicolor cell imaging, and enhanced photothermal therapy. The synthesis of the Fe3O4@PC-CDs-Au NPs firstly involves the preparation of core-shell template NPs with magnetite nanocrystals clustered in the cores and fluorescent carbon dots (CDs) embedded in a porous carbon shell, followed by an in situ reduction of silver ions (Ag+) loaded in the porous carbon shell and a subsequent replacement of Ag NPs with Au NPs through a galvanic replacement reaction using HAuCl4 as a precursor. The Fe3O4@PC-CDs-Au NPs can enter the intracellular region and light up mouse melanoma B16F10 cells in multicolor mode. The porous carbon shell, anchored with hydrophilic hydroxyl/carboxyl groups, endows the Fe3O4@PC-CDs-Au NPs with excellent stability in the aqueous phase and a high loading capacity (719 mg g-1) for the anti-cancer drug doxorubicin (DOX). The superparamagnetic Fe3O4@PC-CDs-Au NPs with a saturation magnetization of 23.26 emu g-1 produce localized heat under an alternating magnetic field, which triggers the release of the loaded drug. The combined photothermal effects of the Au nanocrystals and the CDs on/in the carbon shell can not only regulate the release rate of the loaded drug, but also efficiently kill tumor cells under NIR irradiation. Benefitting from their excellent optical properties, their magnetic field and NIR light-responsive drug release capabilities and their enhanced photothermal effect, such nanostructured Fe3O4@PC-CDs-Au hybrid NPs are very promising for simultaneous imaging diagnostics and high efficacy therapy.This paper reports a type of multifunctional hybrid nanoparticle (NP) composed of gold nanocrystals coated on and/or embedded in a magnetite-fluorescent porous

  13. Tuning the Pore Size in Ionic Nanoparticle Networks

    Directory of Open Access Journals (Sweden)

    Marie-Alexandra Neouze Gauthey

    2013-01-01

    Full Text Available Highly promising hybrid materials consisting of silica, titania, or zirconia nanoparticles linked with ionic liquid-like imidazolium units have been developed. The nanoparticle networks are prepared by click-chemistry-like process through a nucleophilic substitution reaction. The type of metal oxide nanoparticles appears to play a key role regarding the pore size of the hybrid material.

  14. Rational design on controlled release ion-exchange polymeric microspheres and polymer-lipid hybrid nanoparticles for the delivery of water-soluble drugs through a multidisciplinary approach

    Science.gov (United States)

    Li, Yongqiang

    Sulfopropyl dextran sulfate (SP-DS) microspheres and polymer-lipid hybrid nanoparticles (PLN) for the delivery of water-soluble anticancer drugs and P-glycoprotein inhibitors were developed by our group recently and demonstrated effectiveness in local chemotherapy. To optimize the delivery performance of these particulate systems, particularly PLN, an integrated multidisciplinary approach was developed, based on an in-depth understanding of drug-excipient interactions, internal structure, drug loading and release mechanisms, and application of advanced modeling/optimization techniques. An artificial neural networks (ANN) simulator capable of formulation optimization and drug release prediction was developed. In vitro drug release kinetics of SP-DS microspheres, with various drug loading and in different release media, were predicted by ANN. The effects of independent variables on drug release were evaluated. Good modeling performance suggested that ANN is a useful tool to predict drug release from ion-exchange microspheres. To further improve the performance of PLN, drug-polymer-lipid interactions were characterized theoretically and experimentally using verapamil hydrochloride (VRP) as a model drug and dextran sulfate sodium (DS) as a counter-ion polymer. VRP-DS complexation followed a stoichiometric rule and solid-state transformation of VRP were observed. Dodecanoic acid (DA) was identified as the lead lipid carrier material. Based upon the optimized drug-polymer-lipid interactions, PLN with high drug loading capacity (36%, w/w) and sustained release without initial burst release were achieved. VRP remained amorphous and was molecularly dispersed within PLN. H-bonding contributed to the miscibility between the VRP-DS complex and DA. Drug release from PLN was mainly controlled by diffusion and ion-exchange processes. Drug loading capacity and particle size of PLN depend on the formulation factors of the weight ratio of drug to lipid and concentrations of

  15. Graphite and Hybrid Nanomaterials as Lubricant Additives

    Directory of Open Access Journals (Sweden)

    Zhenyu J. Zhang

    2014-04-01

    Full Text Available Lubricant additives, based on inorganic nanoparticles coated with organic outer layer, can reduce wear and increase load-carrying capacity of base oil remarkably, indicating the great potential of hybrid nanoparticles as anti-wear and extreme-pressure additives with excellent levels of performance. The organic part in the hybrid materials improves their flexibility and stability, while the inorganic part is responsible for hardness. The relationship between the design parameters of the organic coatings, such as molecular architecture and the lubrication performance, however, remains to be fully elucidated. A survey of current understanding of hybrid nanoparticles as lubricant additives is presented in this review.

  16. Effect of the content of hydroxyapatite nano-particles on the properties and bioactivity of poly(L-lactide) - hybrid membranes

    OpenAIRE

    Deplaine, H.; Ribelles, J. L. Gómez; Ferrer, G. Gallego

    2010-01-01

    Abstract Poly(L-lactide)/hydroxyapatite, PLLA, composite membranes for bone regeneration with different concentrations of nanoparticles have been prepared and their physicochemical properties and bioactivity have been determined. Hydroxyapatite nanoparticles act as nucleating agent of the poly(L-lactide) crystals, as detected by DSC, and as reinforcing filler, as proven by the monotonous increase of the elastic modulus of the microporous membranes with increasing nanofiller content...

  17. A spectroscopic study on interaction between bovine serum albumin and titanium dioxide nanoparticle synthesized from microwave-assisted hybrid chemical approach.

    Science.gov (United States)

    Ranjan, Shivendu; Dasgupta, Nandita; Srivastava, Priyanka; Ramalingam, Chidambaram

    2016-08-01

    The use of nanoparticles in food or pharma requires a molecular-level perceptive of how NPs interact with protein corona once exposed to a physiological environment. In this study, the conformational changes of bovine serum albumin (BSA) were investigated in detail when exposed to different concentration of titanium dioxide nanoparticle by various techniques. To analyze the effects of NPs on proteins, the interaction between bovine serum albumin and titanium dioxide nanoparticles at different concentrations were investigated. The interaction, BSA conformations, kinetics, and adsorption were analyzed by dynamic light scattering, Fourier transform infrared spectroscopy and fluorescence quenching. Dynamic light scattering analysis confirms the interaction with major changes in the size of the protein. Fluorescence quenching analysis confirms the side-on or end-on interaction of 1.1 molecules of serum albumin to titanium dioxide nanoparticles. Further, pseudo-second order kinetics was determined with equilibrium contact time of 20min. The spectroscopic analysis suggests that there is a conformational change both at secondary and tertiary structure levels. A distortion in both α-helix and β-sheets was observed by Fourier transform infrared (FTIR) spectroscopy. Fluorescence quenching analysis confirms the interaction of a molecule of bovine serum albumin to the single TiO2 nanoparticle. Further, pseudo-second order kinetics was determined with equilibrium contact time of 20min. The data of the present study determines the detailed evaluation of BSA adsorption on TiO2 nanoparticle along with mechanism and adsorption kinetics.

  18. A spectroscopic study on interaction between bovine serum albumin and titanium dioxide nanoparticle synthesized from microwave-assisted hybrid chemical approach.

    Science.gov (United States)

    Ranjan, Shivendu; Dasgupta, Nandita; Srivastava, Priyanka; Ramalingam, Chidambaram

    2016-08-01

    The use of nanoparticles in food or pharma requires a molecular-level perceptive of how NPs interact with protein corona once exposed to a physiological environment. In this study, the conformational changes of bovine serum albumin (BSA) were investigated in detail when exposed to different concentration of titanium dioxide nanoparticle by various techniques. To analyze the effects of NPs on proteins, the interaction between bovine serum albumin and titanium dioxide nanoparticles at different concentrations were investigated. The interaction, BSA conformations, kinetics, and adsorption were analyzed by dynamic light scattering, Fourier transform infrared spectroscopy and fluorescence quenching. Dynamic light scattering analysis confirms the interaction with major changes in the size of the protein. Fluorescence quenching analysis confirms the side-on or end-on interaction of 1.1 molecules of serum albumin to titanium dioxide nanoparticles. Further, pseudo-second order kinetics was determined with equilibrium contact time of 20min. The spectroscopic analysis suggests that there is a conformational change both at secondary and tertiary structure levels. A distortion in both α-helix and β-sheets was observed by Fourier transform infrared (FTIR) spectroscopy. Fluorescence quenching analysis confirms the interaction of a molecule of bovine serum albumin to the single TiO2 nanoparticle. Further, pseudo-second order kinetics was determined with equilibrium contact time of 20min. The data of the present study determines the detailed evaluation of BSA adsorption on TiO2 nanoparticle along with mechanism and adsorption kinetics. PMID:27318604

  19. Preparation and the optical nonlinearity of surface chemistry improved titania nanoparticles in poly(methyl methacrylate)-titania hybrid thin films

    International Nuclear Information System (INIS)

    With 800-nm, 120-fs laser pulses, optical nonlinearity has been studied in a series of thin films containing poly(methyl methacrylate) (PMMA), filled with surfactant acetylacetone (Acac) capped TiO2 nanoparticles, which were synthesized by a simple in situ sol-gel/polymerization process, assisted by spin coating and multi-step baking. The resulting nanohybrid thin films have highly optical transparency and demonstrate a unique nonlinear optical (NLO) response. The highest nonlinear refractive index (n2) is observed up to 6.55 x 10-2 cm2 GW-1 in the nanohybrid thin film of 60 wt% Ti(OBu)4 in PMMA, with a negligible two-photon absorption (TPA), as confirmed by the Z-scan technique. The titanium precursor loading combined with the nature of the capping molecules are used to influence the ability of nanoparticles to nonlinear optical response. Indeed, the ligands at the nanoparticles' surface can not only control the extent of the interaction between the organic molecules and the embedded nanoparticles but also influence the optical nonlinearities of nanoparticles.

  20. Electrical wire explosion process of copper/silver hybrid nano-particle ink and its sintering via flash white light to achieve high electrical conductivity

    Science.gov (United States)

    Chung, Wan-Ho; Hwang, Yeon-Taek; Lee, Seung-Hyun; Kim, Hak-Sung

    2016-05-01

    In this work, combined silver/copper nanoparticles were fabricated by the electrical explosion of a metal wire. In this method, a high electrical current passes through the metal wire with a high voltage. Consequently, the metal wire evaporates and metal nanoparticles are formed. The diameters of the silver and copper nanoparticles were controlled by changing the voltage conditions. The fabricated silver and copper nano-inks were printed on a flexible polyimide (PI) substrate and sintered at room temperature via a flash light process, using a xenon lamp and varying the light energy. The microstructures of the sintered silver and copper films were observed using a scanning electron microscope (SEM) and a transmission electron microscope (TEM). To investigate the crystal phases of the flash-light-sintered silver and copper films, x-ray diffraction (XRD) was performed. The absorption wavelengths of the silver and copper nano-inks were measured using ultraviolet-visible spectroscopy (UV-vis). Furthermore, the resistivity of the sintered silver and copper films was measured using the four-point probe method and an alpha step. As a result, the fabricated Cu/Ag film shows a high electrical conductivity (4.06 μΩcm), which is comparable to the resistivity of bulk copper (1.68 μΩcm). In addition, the fabricated Cu/Ag nanoparticle film shows superior oxidation stability compared to the Cu nanoparticle film.

  1. Electrical wire explosion process of copper/silver hybrid nano-particle ink and its sintering via flash white light to achieve high electrical conductivity.

    Science.gov (United States)

    Chung, Wan-Ho; Hwang, Yeon-Taek; Lee, Seung-Hyun; Kim, Hak-Sung

    2016-05-20

    In this work, combined silver/copper nanoparticles were fabricated by the electrical explosion of a metal wire. In this method, a high electrical current passes through the metal wire with a high voltage. Consequently, the metal wire evaporates and metal nanoparticles are formed. The diameters of the silver and copper nanoparticles were controlled by changing the voltage conditions. The fabricated silver and copper nano-inks were printed on a flexible polyimide (PI) substrate and sintered at room temperature via a flash light process, using a xenon lamp and varying the light energy. The microstructures of the sintered silver and copper films were observed using a scanning electron microscope (SEM) and a transmission electron microscope (TEM). To investigate the crystal phases of the flash-light-sintered silver and copper films, x-ray diffraction (XRD) was performed. The absorption wavelengths of the silver and copper nano-inks were measured using ultraviolet-visible spectroscopy (UV-vis). Furthermore, the resistivity of the sintered silver and copper films was measured using the four-point probe method and an alpha step. As a result, the fabricated Cu/Ag film shows a high electrical conductivity (4.06 μΩcm), which is comparable to the resistivity of bulk copper (1.68 μΩcm). In addition, the fabricated Cu/Ag nanoparticle film shows superior oxidation stability compared to the Cu nanoparticle film.

  2. High-energy X-ray powder diffraction and atomic-pair distribution-function studies of charged/discharged structures in carbon-hybridized Li2MnSiO4 nanoparticles as a cathode material for lithiumion batteries

    Energy Technology Data Exchange (ETDEWEB)

    Moriya, Maki; Miyahara, Masahiko; Hokazono, Mana; Sasaki, Hirokazu; Nemoto, Atsushi; Katayama, Shingo; Akimoto, Yuji; Hirano, Shin-ichi; Ren, Yang

    2014-10-01

    The stable cycling performance with a high discharge capacity of similar to 190 mAh g(-1) in a carbon-hybridized Li2MnSiO4 nanostructured powder has prompted an experimental investigation of the charged/discharged structures using synchrotron-based and laboratory-based X-rays and atomic-pair distributionfunction (PDF) analyses. A novel method of in-situ spray pyrolysis of a precursor solution with glucose as a carbon source enabled the successful synthesis of the carbon-hybridized Li2(M)nSiO(4) nanoparticles. The XRD patters of the discharged (lithiated) samples exhibit a long-range ordered structure characteristic of the (beta) Li2MnSiO4 crystalline phase (space group Pmn2(1)) which dissipates in the charged (delithiated) samples. However, upon discharging the long-range ordered structure recovers in each cycle. The disordered structure, according to the PDF analysis, is mainly due to local distortions of the MnO4 tetrahedra which show a mean Mn-O nearest neighbor distance shorter than that of the long-range ordered phase. These results corroborate the notion of the smaller Mn3+/Mn4+ ionic radii in the Li extracted phase versus the larger Mn2+ ionic radius in Li inserted phase. Thus Li extraction/insertion drives the fluctuation between the disordered and the long-range ordered structures. (C) 2014 Elsevier B.V. All rights reserved.

  3. Manipulating Fano resonance via fs-laser melting of hybrid oligomers at nanoscale

    Science.gov (United States)

    Lepeshov, S. I.; Zuev, D. A.; Makarov, S. V.; Milichko, V. A.; Mukhin, I. S.; Krasnok, A. E.; Belov, P. A.

    2016-08-01

    Here, the novel concept of asymmetric metal-dielectric (hybrid) nanoparticles is proposed. The experimental data and the results of numerical simulation of the optical properties of hybrid nanostructures are presented. The change of their optical response after fs- laser modification is shown. The possibility of manipulating Fano resonance in hybrid oligomers by the gold nanoparticles reshaping is demonstrated.

  4. Influence of ZrO2 nanoparticles and thermal treatment on the properties of PMMA/ZrO2 hybrid coatings

    International Nuclear Information System (INIS)

    Highlights: • PMMA/ZrO2 nanocomposites were prepared by melt blending in a single screw extruder. • The nanoparticles of m-, t-ZrO2 were successfully synthesized using sol–gel technique. • The prepared PMMA/ZrO2 nanocomposites have better UV protection than pure PMMA. • The thermal stability of the PMMA increases with low amount of ZrO2 nanoparticles. • PMMA/ZrO2 nanocomposites show superior values of elastic modulus and hardness. - Abstract: In this work, ZrO2 nanoparticles were synthesized by the sol–gel method, treated thermally at different temperatures (400, 600 and 800 °C), and added to a polymer matrix in two different weight percentages (0.5 and 1) by single screw extrusion in order to determine the influence of these parameters on the thermal stability and UV radiation resistance of PMMA/ZrO2 composites. Fourier transform infrared spectroscopy (FT-IR), nuclear magnetic resonance (NMR), X-ray diffraction (XRD), transmission electron microscopy (TEM), confocal laser scanning microscopy (CLSM), ultraviolet–visible spectroscopy (UV–Vis), thermogravimetric analysis (TGA) and nanoindentation techniques were used to evaluate the structural, morphological, optical, thermal and mechanical properties of as-prepared composites. The average crystallite sizes for ZrO2 sintered at 600 and 800 °C were about 17 and 26 nm, respectively. It was found that the incorporation of a low percentage of ZrO2 nanoparticles increased the thermal properties of PMMA as well as its hardness and elastic modulus. The degradation temperature at 10 wt.% loss of the PMMA/ZrO2 (0.5 wt.%, 400 °C) nanocomposite was approximately 48 °C higher than that of pure PMMA. The absorption in the UV region was increased according to the ZrO2 heat treatment temperature and amount added to the polymer matrix

  5. Hybrid nanoantennas for directional emission enhancement

    International Nuclear Information System (INIS)

    Plasmonic and dielectric nanoparticles offer complementary strengths regarding their use as optical antenna elements. While plasmonic nanoparticles are well-known to provide strong decay rate enhancement for localized emitters, all-dielectric nanoparticles can enable high directivity combined with low losses. Here, we suggest a hybrid metal-dielectric nanoantenna consisting of a gold nanorod and a silicon nanodisk, which combines all these advantages. Our numerical analysis reveals a giant enhancement of directional emission together with simultaneously high radiation efficiency (exceeding 70%). The suggested hybrid nanoantenna has a subwavelength footprint, and all parameters and materials are chosen to be compatible with fabrication by two-step electron-beam lithography

  6. Hybrid nanoantennas for directional emission enhancement

    Energy Technology Data Exchange (ETDEWEB)

    Rusak, Evgenia; Staude, Isabelle, E-mail: isabelle.staude@anu.edu.au; Decker, Manuel; Sautter, Jürgen; Miroshnichenko, Andrey E.; Powell, David A.; Neshev, Dragomir N.; Kivshar, Yuri S. [Nonlinear Physics Centre and Centre for Ultrahigh Bandwidth Devices for Optical Systems (CUDOS), Research School of Physics and Engineering, The Australian National University, Canberra, ACT 2601 (Australia)

    2014-12-01

    Plasmonic and dielectric nanoparticles offer complementary strengths regarding their use as optical antenna elements. While plasmonic nanoparticles are well-known to provide strong decay rate enhancement for localized emitters, all-dielectric nanoparticles can enable high directivity combined with low losses. Here, we suggest a hybrid metal-dielectric nanoantenna consisting of a gold nanorod and a silicon nanodisk, which combines all these advantages. Our numerical analysis reveals a giant enhancement of directional emission together with simultaneously high radiation efficiency (exceeding 70%). The suggested hybrid nanoantenna has a subwavelength footprint, and all parameters and materials are chosen to be compatible with fabrication by two-step electron-beam lithography.

  7. From silicon to organic nanoparticle memory devices.

    Science.gov (United States)

    Tsoukalas, D

    2009-10-28

    After introducing the operational principle of nanoparticle memory devices, their current status in silicon technology is briefly presented in this work. The discussion then focuses on hybrid technologies, where silicon and organic materials have been combined together in a nanoparticle memory device, and finally concludes with the recent development of organic nanoparticle memories. The review is focused on the nanoparticle memory concept as an extension of the current flash memory device. Organic nanoparticle memories are at a very early stage of research and have not yet found applications. When this happens, it is expected that they will not directly compete with mature silicon technology but will find their own areas of application.

  8. Controlled photoluminescence from self-assembled semiconductor-metal quantum dot hybrid array films

    International Nuclear Information System (INIS)

    Thin films of hybrid arrays of cadmium selenide quantum dots and polymer grafted gold nanoparticles have been prepared using a BCP template. Controlling the dispersion and location of the respective nanoparticles allows us to tune the exciton-plasmon interaction in such hybrid arrays and hence control their optical properties. The observed photoluminescence of the hybrid array films is interpreted in terms of the dispersion and location of the gold nanoparticles and quantum dots in the block copolymer matrix.

  9. Influence of ZrO{sub 2} nanoparticles and thermal treatment on the properties of PMMA/ZrO{sub 2} hybrid coatings

    Energy Technology Data Exchange (ETDEWEB)

    Reyes-Acosta, M.A. [Instituto Politécnico Nacional, CICATA-Altamira, CIAMS (Mexico); Instituto Politécnico Nacional, CICATA-Altamira, Km 14.5 Carretera Tampico-Puerto Industrial Altamira, C.P. 89600 Altamira, Tamps. (Mexico); Torres-Huerta, A.M., E-mail: atorresh@ipn.mx [Instituto Politécnico Nacional, CICATA-Altamira, Km 14.5 Carretera Tampico-Puerto Industrial Altamira, C.P. 89600 Altamira, Tamps. (Mexico); Domínguez-Crespo, M.A. [Instituto Politécnico Nacional, CICATA-Altamira, Km 14.5 Carretera Tampico-Puerto Industrial Altamira, C.P. 89600 Altamira, Tamps. (Mexico); Flores-Vela, A.I. [Instituto Politécnico Nacional, CMP+L, Av. Acueducto s/n, Barrio La Laguna, Col. Ticomán, C.P. 07340 México D.F. (Mexico); Dorantes-Rosales, H.J. [Instituto Politécnico Nacional, SEPI-ESIQIE, Departamento de Metalurgia, C.P. 07738 México D.F. (Mexico); Ramírez-Meneses, E. [Departamento de Ingeniería y Ciencias Químicas, Universidad Iberoamericana, Prolongación Paseo de la Reforma 880, Lomas de Santa Fe, Distrito Federal C.P. 01219 (Mexico)

    2015-09-15

    Highlights: • PMMA/ZrO{sub 2} nanocomposites were prepared by melt blending in a single screw extruder. • The nanoparticles of m-, t-ZrO{sub 2} were successfully synthesized using sol–gel technique. • The prepared PMMA/ZrO{sub 2} nanocomposites have better UV protection than pure PMMA. • The thermal stability of the PMMA increases with low amount of ZrO{sub 2} nanoparticles. • PMMA/ZrO{sub 2} nanocomposites show superior values of elastic modulus and hardness. - Abstract: In this work, ZrO{sub 2} nanoparticles were synthesized by the sol–gel method, treated thermally at different temperatures (400, 600 and 800 °C), and added to a polymer matrix in two different weight percentages (0.5 and 1) by single screw extrusion in order to determine the influence of these parameters on the thermal stability and UV radiation resistance of PMMA/ZrO{sub 2} composites. Fourier transform infrared spectroscopy (FT-IR), nuclear magnetic resonance (NMR), X-ray diffraction (XRD), transmission electron microscopy (TEM), confocal laser scanning microscopy (CLSM), ultraviolet–visible spectroscopy (UV–Vis), thermogravimetric analysis (TGA) and nanoindentation techniques were used to evaluate the structural, morphological, optical, thermal and mechanical properties of as-prepared composites. The average crystallite sizes for ZrO{sub 2} sintered at 600 and 800 °C were about 17 and 26 nm, respectively. It was found that the incorporation of a low percentage of ZrO{sub 2} nanoparticles increased the thermal properties of PMMA as well as its hardness and elastic modulus. The degradation temperature at 10 wt.% loss of the PMMA/ZrO{sub 2} (0.5 wt.%, 400 °C) nanocomposite was approximately 48 °C higher than that of pure PMMA. The absorption in the UV region was increased according to the ZrO{sub 2} heat treatment temperature and amount added to the polymer matrix.

  10. New ZrO2/Al2O3 Nanocomposite Fabricated from Hybrid Nanoparticles Prepared by CO2 Laser Co-Vaporization

    OpenAIRE

    José F Bartolomé; Anton Smirnov; Heinz-Dieter Kurland; Janet Grabow; Frank A. Müller

    2016-01-01

    Alumina toughened zirconia (ATZ) and zirconia toughened alumina (ZTA) are currently the materials of choice to meet the need for tough, strong, and bioinert ceramics for medical devices. However, the mechanical properties of ZrO2/Al2O3 dispersion ceramics could be considerably increased by reducing the corresponding grain sizes and by improving the homogeneity of the phase dispersion. Here, we prepare nanoparticles with an intraparticular phase distribution of Zr(1−x)AlxO(2−x/2) and (γ-, δ-)A...

  11. Hybrid mesoporous silica nanoparticles with pH-operated and complementary H-bonding caps as an autonomous drug-delivery system.

    Science.gov (United States)

    Théron, Christophe; Gallud, Audrey; Carcel, Carole; Gary-Bobo, Magali; Maynadier, Marie; Garcia, Marcel; Lu, Jie; Tamanoi, Fuyuhiko; Zink, Jeffrey I; Wong Chi Man, Michel

    2014-07-21

    Mesoporous silica nanoparticles (MSNPs) are functionalized with molecular-recognition sites by anchoring a triazine or uracil fragment on the surface. After loading these MSNPs with dyes (propidium iodide or rhodamine B) or with a drug (camptothecin, CPT) they are capped by the complementary fragments, uracil and adenine, respectively, linked to the bulky cyclodextrin ring. These MSNPs are pH-sensitive and indeed, the dye release was observed at acidic pH by continuously monitored fluorescence spectroscopy studies. On the other hand, no dye leakage occurred at neutral pH, hence meeting the non-premature requirement to minimize side effects. In vitro studies were performed and confocal microscopy images demonstrate the internalization of the MSNPs and also dye release in the cells. To investigate the drug-delivery performance, the cytotoxicity of CPT-loaded nanoparticles was tested and cell death was observed. A remarkably lower amount of loaded CPT in the MSNPs (more than 40 times less) proved to be as efficient as free CPT. These results not only demonstrate the drug release after pore opening under lysosomal pH, but they also show the potential use of these MSNPs to significantly decrease the amount of the administered drug. PMID:24986399

  12. Ni/Carbon Hybrid Prepared by Hydrothermal Carbonization and Thermal Treatment as Support for PtRu Nanoparticles for Direct Methanol Fuel Cell

    Institute of Scientific and Technical Information of China (English)

    Marcelo Marques Tusi; Michele Brandalise; Nataly Soares de Oliveira Polanco; Olandir Vercino Correa; Antonio Carlos da Silva; Juan Carlo Villalba; Fauze Jaco Anaissi

    2013-01-01

    Ni/Carbon was prepared in two steps:initially cellulose as carbon source and NiCl2.6H20 as catalyst of the carbonization process were submitted to hydrothermal treatment at 200 ℃ and further to thermal treatment at 900 ℃ under argon atmosphere.The obtained material contains Ni nanoparticles with face-centered cubic (fcc) structure dispersed on amorphous carbon with graphitic domains.PtRu/C electrocatalysts (carbonsupported PtRu nanoparticles) were prepared by an alcohol-reduction process using Ni/Carbon as support.The materials were characterized by thermogravimetric analysis,energy-dispersive X-ray spectroscopy,Fourier transform infrared spectroscopy,X-ray diffraction,transmission electron microscopy and tested as anodes in single direct methanol fuel cell (DMFC).The performances of PtRu/C electrocatalysts using Ni/Carbon as support were superior to those obtained for PtRu/C using commercial carbon black Vulcan XC72 as support.

  13. Enhancing UV-emissions through optical and electronic dual-function tuning of Ag nanoparticles hybridized with n-ZnO nanorods/p-GaN heterojunction light-emitting diodes.

    Science.gov (United States)

    Yao, Yung-Chi; Yang, Zu-Po; Hwang, Jung-Min; Chuang, Yi-Lun; Lin, Chia-Ching; Haung, Jing-Yu; Chou, Chun-Yang; Sheu, Jinn-Kong; Tsai, Meng-Tsan; Lee, Ya-Ju

    2016-02-28

    ZnO nanorods (NRs) and Ag nanoparticles (NPs) are known to enhance the luminescence of light-emitting diodes (LEDs) through the high directionality of waveguide mode transmission and efficient energy transfer of localized surface plasmon (LSP) resonances, respectively. In this work, we have demonstrated Ag NP-incorporated n-ZnO NRs/p-GaN heterojunctions by facilely hydrothermally growing ZnO NRs on Ag NP-covered GaN, in which the Ag NPs were introduced and randomly distributed on the p-GaN surface to excite the LSP resonances. Compared with the reference LED, the light-output power of the near-band-edge (NBE) emission (ZnO, λ = 380 nm) of our hybridized structure is increased almost 1.5-2 times and can be further modified in a controlled manner by varying the surface morphology of the surrounding medium of the Ag NPs. The improved light-output power is mainly attributed to the LSP resonance between the NBE emission of ZnO NRs and LSPs in Ag NPs. We also observed different behaviors in the electroluminescence (EL) spectra as the injection current increases for the treatment and reference LEDs. This observation might be attributed to the modification of the energy band diagram for introducing Ag NPs at the interface between n-ZnO NRs and p-GaN. Our results pave the way for developing advanced nanostructured LED devices with high luminescence efficiency in the UV emission regime.

  14. Hybrid response surface methodology-genetic algorithm optimization of ultrasound-assisted transesterification of waste oil catalysed by immobilized lipase on mesoporous silica/iron oxide magnetic core-shell nanoparticles.

    Science.gov (United States)

    Karimi, Mahmoud; Keyhani, Alireza; Akram, Asadolah; Rahman, Masoud; Jenkins, Bryan; Stroeve, Pieter

    2013-01-01

    The production ofbiodiesel by transesterification of waste cooking oil (WCO) to partially substitute petroleum diesel is one of the measures for solving the twin problems of environment pollution and energy demand. An environmentally benign process for the enzymatic transesterification using immobilized lipase has attracted considerable attention for biodiesel production. Here, a superparamagnetic, high surface area substrate for lipase immobilization is evaluated. These immobilization substrates are composed of mesoporous silica/superparamagnetic iron oxide core-shell nanoparticles. The effects of methanol ratio to WCO, lipase concentration, water content and reaction time on the synthesis of biodiesel were analysed by utilizing the response surface methodology (RSM). A quadratic response surface equation for calculating fatty acid methyl ester (FAME) content as the objective function was established based on experimental data obtained in accordance with the central composite design. The RSM-based model was then used as the fitness function for genetic algorithm (GA) to optimize its input space. Hybrid RSM-GA predicted the maximum FAME content (91%) at the optimum level of medium variables: methanol ratio to WCO, 4.34; lipase content, 43.6%; water content, 10.22%; and reaction time, 6h. Moreover, the immobilized lipase could be used for four times without considerable loss of the activity. PMID:24350474

  15. Hybrid silica nanoparticles for sequestration and luminescence detection of trivalent rare-earth ions (Dy{sup 3+} and Nd{sup 3+}) in solution

    Energy Technology Data Exchange (ETDEWEB)

    Topel, Seda Demirel; Legaria, Elizabeth Polido [Swedish University of Agricultural Sciences (SLU), Department of Chemistry (Sweden); Tiseanu, Carmen [National Institute for Laser, Plasma and Radiation Physics (Romania); Rocha, João [University of Aveiro, Department of Chemistry CICECO (Portugal); Nedelec, Jean-Marie [Clermont Université, ENSCCF, Institute de Chimie de Clermont-Ferrand (France); Kessler, Vadim G.; Seisenbaeva, Gulaim A., E-mail: gulaim.seisenbaeva@slu.se [Swedish University of Agricultural Sciences (SLU), Department of Chemistry (Sweden)

    2014-12-15

    New hybrid material-based adsorbents acting also as luminescent probes upon uptake of trivalent rare-earth (RE) ions Nd{sup 3+} and Dy{sup 3+} have been developed. SiO{sub 2} NPs functionalized by three different organic ligands, N-aminopropylen-amido-iminodiacetic acid (L1), pyridine-α,β-dicarboxylic acid bis(propylenamide) (L2), and N-propylen-iminodiacetic acid (L3), have been produced and fully characterized by {sup 13}C, {sup 1}H, and {sup 29}Si solid-state NMR, FTIR, TGA, XRD, TEM, nitrogen gas adsorption, and also by NTA and DLS in solution. The synthesized hybrid materials are well dispersible and stable in aqueous solutions according to NTA and consist of spheres with diameters less than 100 nm. Their affinities to the lanthanide ions Dy{sup 3+} and Nd{sup 3+} have been investigated in aqueous solution and characterized by SEM–EDS and complexometric titration, demonstrating that they can be successfully used as adsorbents for sequestration of trivalent RE ions. The adsorbed RE ions can efficiently be desorbed from saturated nanoadsorbents by addition of hydrochloric acid. The produced nanomaterials may also be used as luminescent probes for Dy{sup 3+} and Nd{sup 3+} ions in solution.

  16. Organic-Inorganic Hybrid Nanoparticles for Bacterial Inhibition: Synthesis and Characterization of Doped and Undoped ONPs with Ag/Au NPs

    Directory of Open Access Journals (Sweden)

    Carlos Alberto Huerta Aguilar

    2015-04-01

    Full Text Available Organic nanoparticles (ONPs of lipoic acid and its doped derivatives ONPs/Ag and ONPs/Au were prepared and characterized by UV-Visible, EDS, and TEM analysis. The antibacterial properties of the ONPs ONPs/Ag and ONPs/Au were tested against bacterial strains (Staphylococcus aureus, Bacillus cereus, Escherichia coli and Salmonella typhi. Minimal Inhibitory Concentration (MIC and bacterial growth inhibition tests show that ONPs/Ag are more effective in limiting bacterial growth than other NPs, particularly, for Gram positive than for Gram-negative ones. The order of bacterial cell growth inhibition was ONPs/Ag > ONPs > ONPs/Au. The morphology of the cell membrane for the treated bacteria was analyzed by SEM. The nature of bond formation of LA with Ag or Au was analyzed by molecular orbital and density of state (DOS using DFT.

  17. Visual detection of telomerase activity with a tunable dynamic range by using a gold nanoparticle probe-based hybridization protection strategy

    Science.gov (United States)

    Wang, Jiasi; Wu, Li; Ren, Jinsong; Qu, Xiaogang

    2014-01-01

    We developed a novel telomere complementary (TC) oligonucleotide modified AuNP probe (TC-AuNPs) for colorimetric analysis of telomerase activity. The mechanism of this method is that the telomerase reaction products (TRP), which can hybridize with the TC-AuNPs, are able to protect the AuNPs from the aggregation induced by salt. It is demonstrated that the colorimetric method enabled the analysis of the telomerase activity in 1000 HeLa cells with the naked eye, and down to 100 HeLa cells with the aid of UV-Vis spectroscopy. This strategy is not only convenient and sensitive, but also has a tunable dynamic range. The platform is also applicable for the initial screening of a telomerase inhibitor to discover new anticancer drugs.We developed a novel telomere complementary (TC) oligonucleotide modified AuNP probe (TC-AuNPs) for colorimetric analysis of telomerase activity. The mechanism of this method is that the telomerase reaction products (TRP), which can hybridize with the TC-AuNPs, are able to protect the AuNPs from the aggregation induced by salt. It is demonstrated that the colorimetric method enabled the analysis of the telomerase activity in 1000 HeLa cells with the naked eye, and down to 100 HeLa cells with the aid of UV-Vis spectroscopy. This strategy is not only convenient and sensitive, but also has a tunable dynamic range. The platform is also applicable for the initial screening of a telomerase inhibitor to discover new anticancer drugs. Electronic supplementary information (ESI) available. See DOI: 10.1039/c3nr05185d

  18. One-pot deposition of gold on hybrid TiO{sub 2} nanoparticles and catalytic application in the selective oxidation of benzyl alcohol

    Energy Technology Data Exchange (ETDEWEB)

    Mehri, Afef [University Tunis El-Manar, Laboratoire de Chimie des Matériaux et Catalyse, Tunis (Tunisia); Kochkar, Hafedh, E-mail: h_kochkar@yahoo.fr [University Tunis El-Manar, Laboratoire de Chimie des Matériaux et Catalyse, Tunis (Tunisia); Laboratoire de Valorisation des Matériaux Utiles, Centre National de Recherches en Sciences des Matériaux, Technopôle de Borj-Cedria, 2050 Hammam-Lif (Tunisia); Berhault, Gilles [Institut de Recherches sur la Catalyse et de l' Environnement de Lyon, CNRS-Université Lyon I, 69100 Villeurbanne (France); Cómbita Merchán, Diego Fernando; Blasco, Teresa [Instituto de Tecnología Química (UPV-CSIC), Universidad Politécnica de Valencia-Consejo Superior de Investigaciones Científicas, Avda. de los Naranjos, s/n, Valencia (Spain)

    2015-01-15

    One-pot deposition of Au onto TiO{sub 2} has been achieved through directly contacting gold (III) salt with nanosized functionalized TiO{sub 2} support initially obtained by sol–gel process using titanium isopropoxide and citric acid. Citrate groups act as functional moieties able to directly reduce the Au salt avoiding any further reducing treatment. Various gold salts (NaAuCl{sub 4}·2H{sub 2}O or HAuCl{sub 4}·3H{sub 2}O) and titanium to citrate (Ti/Cit) molar ratios (20, 50 and 100) were used in order to study the effect of the nature of the precursor and of the citrate content on the final Au particle size and catalytic properties of the as-obtained Au/TiO{sub 2} materials. Au/(TiO{sub 2}){sub x}(Cit){sub 1} catalysts characterization was performed using N{sub 2} adsorption–desorption, ICP-AES, X-ray diffraction and TEM. The effect of the Ti/Cit molar ratio and of the gold precursor was evaluated. The selective oxidation of benzyl alcohol (BzOH) to benzaldehyde (BzH) was studied as a model reaction. Kinetic analysis showed that the catalytic reaction rate was pseudo first-order and the values of activation energy have been reported. Results showed that the functionalization of TiO{sub 2} by citrate allows tuning the size of the Au nanoparticles deposited onto TiO{sub 2} as well as their morphology. Citrate also strongly enhances the benzyl alcohol oxidation through the control of the size and morphology of gold nanoparticles. - Highlights: • One-pot deposition of Au onto TiO{sub 2} has been achieved. • Citrates act as active sites for selective deposition and reduction of gold. • The presence of citrates influences the size and the morphology of gold NPs. • Au NPs with well-defined morphologies were obtained for Cit/Ti molar ratio of 100. • The selective oxidation of benzyl alcohol was studied as a model reaction.

  19. Angular velocity response of nanoparticles dispersed in liquid crystal

    Science.gov (United States)

    Huang, Pin-Chun; Shih, Wen-Pin

    2013-06-01

    A hybrid material of nanoparticles dispersed in liquid crystal changed capacitance after spinning beyond threshold angular velocity. Once the centrifugal force of nanoparticles overcomes the attractive force between liquid crystals, the nanoparticles begin to move. The order of highly viscous liquid crystals is disturbed by the nanoparticles' penetrative movement, and the dielectric constant of the liquid crystal cell changes as a result. We found that the angular velocity response of nanoparticles dispersed in liquid crystal with higher working temperature and nanoparticles' density provided higher sensitivity. The obtained results are important for the continuous improvement of liquid-crystal-based inertial sensors or nano-viscometers.

  20. New ZrO2/Al2O3 Nanocomposite Fabricated from Hybrid Nanoparticles Prepared by CO2 Laser Co-Vaporization

    Science.gov (United States)

    Bartolomé, José F.; Smirnov, Anton; Kurland, Heinz-Dieter; Grabow, Janet; Müller, Frank A.

    2016-01-01

    Alumina toughened zirconia (ATZ) and zirconia toughened alumina (ZTA) are currently the materials of choice to meet the need for tough, strong, and bioinert ceramics for medical devices. However, the mechanical properties of ZrO2/Al2O3 dispersion ceramics could be considerably increased by reducing the corresponding grain sizes and by improving the homogeneity of the phase dispersion. Here, we prepare nanoparticles with an intraparticular phase distribution of Zr(1−x)AlxO(2−x/2) and (γ-, δ-)Al2O3 by the simultaneous gas phase condensation of laser co-vaporized zirconia and alumina raw powders. During subsequent spark plasma sintering the zirconia defect structures and transition alumina phases transform to a homogeneously distributed dispersion of tetragonal ZrO2 (52.4 vol%) and α-Al2O3 (47.6 vol%). Ceramics sintered by spark plasma sintering are completely dense with average grain sizes in the range around 250 nm. Outstanding mechanical properties (flexural strength σf = 1500 MPa, fracture toughness KIc = 6.8 MPa m1/2) together with a high resistance against low temperature degradation make these materials promising candidates for next generation bioceramics in total hip replacements and for dental implants. PMID:26846310

  1. New ZrO2/Al2O3 Nanocomposite Fabricated from Hybrid Nanoparticles Prepared by CO2 Laser Co-Vaporization

    Science.gov (United States)

    Bartolomé, José F.; Smirnov, Anton; Kurland, Heinz-Dieter; Grabow, Janet; Müller, Frank A.

    2016-02-01

    Alumina toughened zirconia (ATZ) and zirconia toughened alumina (ZTA) are currently the materials of choice to meet the need for tough, strong, and bioinert ceramics for medical devices. However, the mechanical properties of ZrO2/Al2O3 dispersion ceramics could be considerably increased by reducing the corresponding grain sizes and by improving the homogeneity of the phase dispersion. Here, we prepare nanoparticles with an intraparticular phase distribution of Zr(1-x)AlxO(2-x/2) and (γ-, δ-)Al2O3 by the simultaneous gas phase condensation of laser co-vaporized zirconia and alumina raw powders. During subsequent spark plasma sintering the zirconia defect structures and transition alumina phases transform to a homogeneously distributed dispersion of tetragonal ZrO2 (52.4 vol%) and α-Al2O3 (47.6 vol%). Ceramics sintered by spark plasma sintering are completely dense with average grain sizes in the range around 250 nm. Outstanding mechanical properties (flexural strength σf = 1500 MPa, fracture toughness KIc = 6.8 MPa m1/2) together with a high resistance against low temperature degradation make these materials promising candidates for next generation bioceramics in total hip replacements and for dental implants.

  2. Facile fabrication of FeN nanoparticles/nitrogen-doped graphene core-shell hybrid and its use as a platform for NADH detection in human blood serum.

    Science.gov (United States)

    Balamurugan, Jayaraman; Thanh, Tran Duy; Kim, Nam Hoon; Lee, Joong Hee

    2016-09-15

    Herein, we present a novel strategy for the synthesis of an iron nitride nanoparticles-encapsulated nitrogen-doped graphene (FeN NPs/NG) core-shell hierarchical nanostructure to boost the electrochemical performance in a highly sensitive, selective, reproducible, and stable sensing platform for nicotinamide adenine dinucleotide (NADH). This core-shell hierarchical nanostructure provides an excellent conductive network for effective charge transfer and avoids the agglomeration and restacking of NG sheets, which provides better access to the electrode material for NADH oxidation. The FeN NPs/NG core-shell hierarchical nanostructure demonstrates direct and mediatorless responses to NADH oxidation at a low potential. This material displays a high sensitivity of 0.028μA/μMcm(2), a wide linear range from 0.4 to 718μM, and a detection limit of 25nM with a fast response time of less than 3s. The interferences from common interferents, such as glucose, uric acid, dopamine, and ascorbic acid, are negligible. The fabricated sensor was further tested for the determination of NADH in human blood serum. The resulting high sensitivity, excellent selectivity, outstanding stability, and good reproducibility make the proposed FeN NPs/NG core-shell hierarchical nanostructure as a promising candidate for biomedical applications. PMID:27104586

  3. Impedimetric biosensor based on self-assembled hybrid cystein-gold nanoparticles and CramoLL lectin for bacterial lipopolysaccharide recognition.

    Science.gov (United States)

    Oliveira, Maria D L; Andrade, Cesar A S; Correia, Maria T S; Coelho, Luana C B B; Singh, Pankaj R; Zeng, Xiangqun

    2011-10-01

    We report the development of a new selective and specific electrochemical biosensor for bacterial lipolysaccharide (LPS). An electrode interface was constructed using a l-cysteine-gold nanoparticle (AuNpCys) composite to be immobilized by electrostatic interaction in the network of a poly(vinyl chloride-vinyl acetate maleic acid) (PVM) layer on a gold bare electrode. The impedimetric biosensor is fabricated by self-assembled CramoLL lectin on the PVM-AuNpCys-modified gold electrode through electrostatic interaction. CramoLL is used as the recognition interface. AFM images showed that LPS was specifically recognized on the PVM-AuNpCys-CramoLL system surface. The measurements of cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS) showed that the electrochemical response of a redox probe system (K(4)[Fe(CN)(6)](4-)/K(3)[Fe(CN)(6)](3-)) were blocked, due to the procedures of modified electrode with PVM-AuNpCys-CramoLL. In the majority of the experiments the lectin retained its activity as observed through its interaction with LPS from Escherichia coli, Serratia marcescens, Salmonella enterica and Klebsiella pneumoniae. The results are expressed in terms of the charge transfer resistance and current peak anodic using the EIS and CV techniques for the development of a biosensor for contamination by endotoxins. A new type of sensor for selective discrimination of LPS types with a high sensitivity has been obtained. PMID:21752390

  4. DNA immobilization and hybridization on graphene/gold nanoparticles/polypyrrole nanocomposite%DN A在石墨烯/金纳米/聚吡咯复合材料上的固定及杂交

    Institute of Scientific and Technical Information of China (English)

    王明花; 杨光; 张园厂; 康萌萌; 何领好; 冯孝中; 彭东来; 张治红

    2014-01-01

    采用原位化学氧化聚合法制备石墨烯/金纳米/聚吡咯(G/AuNPs/PPy)纳米复合材料,并在其表面进行DNA的固定及杂交.使用傅里叶变换红外光谱、X-射线光电子能谱、场发射扫描电子显微镜及透射电子显微镜对复合材料的化学结构、元素组成和表面形貌进行表征,DNA固定及杂交前后复合材料电化学性能和质量的变化运用电化学循环伏安、交流阻抗和石英晶体微天平等方法测试,结果表明,G/AuNPs/PPy复合材料电化学性能明显优于G/AuNPs二元材料,且DNA在复合材料表面的固定量可达307 ng,同时能检测到357 ng完全匹配靶向DNA.%Graphene/gold nanoparticles/polypyrrole (G/AuNPs/PPy)nanocomposite was prepared by in-situ chemical oxidation method,then DNA was immobilized and hybridized on the surface of the composite. The chemical structure,element composition and surface morphology of the nanocomposite were character-ized by Fourier transform infrared spectroscopy,X-ray photoelectron spectroscopy,field emission scanning electron microscope and transmission electron microscopy,respectively.Afterwards,electrochemical cyclic voltammetry,impedance spectroscopy and electrochemical quartz crystal microbalance were used to deter-mine the variation of electrochemical properties and weight of the nanocomposite before and after DNA im-mobilization/hybridization.It demonstrated that the electrochemical activities of G/AuNPs/PPy were better than that of G/AuNPs nanocomposite.The immobilization amount of DNA on the G/AuNPs/PPy nanocom-posite was 307 ng,and aslo 357 ng of perfectly matched target DNA was detected on the surface.

  5. Core-shell hybrid upconversion nanoparticles carrying stable nitroxide radicals as potential multifunctional nanoprobes for upconversion luminescence and magnetic resonance dual-modality imaging

    Science.gov (United States)

    Chen, Chuan; Kang, Ning; Xu, Ting; Wang, Dong; Ren, Lei; Guo, Xiangqun

    2015-03-01

    Nitroxide radicals, such as 2,2,6,6-tetramethylpiperidine 1-oxyl (TEMPO) and its derivatives, have recently been used as contrast agents for magnetic resonance imaging (MRI) and electron paramagnetic resonance imaging (EPRI). However, their rapid one-electron bioreduction to diamagnetic N-hydroxy species when administered intravenously has limited their use in in vivo applications. In this article, a new approach of silica coating for carrying stable radicals was proposed. A 4-carboxyl-TEMPO nitroxide radical was covalently linked with 3-aminopropyl-trimethoxysilane to produce a silanizing TEMPO radical. Utilizing a facile reaction based on the copolymerization of silanizing TEMPO radicals with tetraethyl orthosilicate in reverse microemulsion, a TEMPO radicals doped SiO2 nanostructure was synthesized and coated on the surface of NaYF4:Yb,Er/NaYF4 upconversion nanoparticles (UCNPs) to generate a novel multifunctional nanoprobe, PEGylated UCNP@TEMPO@SiO2 for upconversion luminescence (UCL) and magnetic resonance dual-modality imaging. The electron spin resonance (ESR) signals generated by the TEMPO@SiO2 show an enhanced reduction resistance property for a period of time of up to 1 h, even in the presence of 5 mM ascorbic acid. The longitudinal relaxivity of PEGylated UCNPs@TEMPO@SiO2 nanocomposites is about 10 times stronger than that for free TEMPO radicals. The core-shell NaYF4:Yb,Er/NaYF4 UCNPs synthesized by this modified user-friendly one-pot solvothermal strategy show a significant enhancement of UCL emission of up to 60 times more than the core NaYF4:Yb,Er. Furthermore, the PEGylated UCNP@TEMPO@SiO2 nanocomposites were further used as multifunctional nanoprobes to explore their performance in the UCL imaging of living cells and T1-weighted MRI in vitro and in vivo.Nitroxide radicals, such as 2,2,6,6-tetramethylpiperidine 1-oxyl (TEMPO) and its derivatives, have recently been used as contrast agents for magnetic resonance imaging (MRI) and electron

  6. Enhancing UV-emissions through optical and electronic dual-function tuning of Ag nanoparticles hybridized with n-ZnO nanorods/p-GaN heterojunction light-emitting diodes

    Science.gov (United States)

    Yao, Yung-Chi; Yang, Zu-Po; Hwang, Jung-Min; Chuang, Yi-Lun; Lin, Chia-Ching; Haung, Jing-Yu; Chou, Chun-Yang; Sheu, Jinn-Kong; Tsai, Meng-Tsan; Lee, Ya-Ju

    2016-02-01

    ZnO nanorods (NRs) and Ag nanoparticles (NPs) are known to enhance the luminescence of light-emitting diodes (LEDs) through the high directionality of waveguide mode transmission and efficient energy transfer of localized surface plasmon (LSP) resonances, respectively. In this work, we have demonstrated Ag NP-incorporated n-ZnO NRs/p-GaN heterojunctions by facilely hydrothermally growing ZnO NRs on Ag NP-covered GaN, in which the Ag NPs were introduced and randomly distributed on the p-GaN surface to excite the LSP resonances. Compared with the reference LED, the light-output power of the near-band-edge (NBE) emission (ZnO, λ = 380 nm) of our hybridized structure is increased almost 1.5-2 times and can be further modified in a controlled manner by varying the surface morphology of the surrounding medium of the Ag NPs. The improved light-output power is mainly attributed to the LSP resonance between the NBE emission of ZnO NRs and LSPs in Ag NPs. We also observed different behaviors in the electroluminescence (EL) spectra as the injection current increases for the treatment and reference LEDs. This observation might be attributed to the modification of the energy band diagram for introducing Ag NPs at the interface between n-ZnO NRs and p-GaN. Our results pave the way for developing advanced nanostructured LED devices with high luminescence efficiency in the UV emission regime.ZnO nanorods (NRs) and Ag nanoparticles (NPs) are known to enhance the luminescence of light-emitting diodes (LEDs) through the high directionality of waveguide mode transmission and efficient energy transfer of localized surface plasmon (LSP) resonances, respectively. In this work, we have demonstrated Ag NP-incorporated n-ZnO NRs/p-GaN heterojunctions by facilely hydrothermally growing ZnO NRs on Ag NP-covered GaN, in which the Ag NPs were introduced and randomly distributed on the p-GaN surface to excite the LSP resonances. Compared with the reference LED, the light-output power of the

  7. Synergetic signal amplification based on electrochemical reduced graphene oxide-ferrocene derivative hybrid and gold nanoparticles as an ultra-sensitive detection platform for bisphenol A

    Energy Technology Data Exchange (ETDEWEB)

    Huang, Na; Liu, Meiling, E-mail: liumeilingww@126.com; Li, Haitao; Zhang, Youyu; Yao, Shouzhuo

    2015-01-01

    Highlights: • A novel (4-ferrocenylethyne) phenylamine was firstly covalently grafted onto GO. • The rGO-Fc-NH{sub 2}/AuNPs composite has good conductivity and compatibility. • The nanocomposite effectively prevent the electron mediator leaking from electrode. • A synergetic amplification platform to ultra-sensitive detect BPA was established. - Abstract: In this paper, a novel electro-active graphene oxide (GO) nanocomposite was firstly prepared by covalently grafted (4-ferrocenylethyne) phenylamine (Fc-NH{sub 2}) onto the surface of GO. The synthesized hybridized nanocomposite of GO-Fc-NH{sub 2} coupled with HAuCl{sub 4} simultaneously electrodeposited on the glassy carbon electrodes (GCE) to obtain rGO-Fc-NH{sub 2}/AuNPs/GCE. The covalently grafted material of the rGO-Fc-NH{sub 2}/AuNPs film can effectively prevent the electron mediator leaking from the electrode surface, which can hold the advantage of both the nanomaterials and electron mediator. By employing the catalysis effect of the nanomaterial and electron mediator coupling with large active surface area and high accumulation capacity of rGO-Fc-NH{sub 2}/AuNPs, a synergetic signal amplification platform for ultra-sensitive detection of bisphenol A (BPA) was successfully established. With this novel sensor, the oxidation peak currents of BPA were linearly dependent on the BPA concentrations in the range of 0.005–10 μM with the detection limit of 2 nM. Modification of electron mediators on nanomaterials can greatly enhance the electrochemical performance of the sensors and will provide a new concept for fabricating newly electro-active nanomaterials-based electrochemical biosensors.

  8. Synergetic signal amplification based on electrochemical reduced graphene oxide-ferrocene derivative hybrid and gold nanoparticles as an ultra-sensitive detection platform for bisphenol A

    International Nuclear Information System (INIS)

    Highlights: • A novel (4-ferrocenylethyne) phenylamine was firstly covalently grafted onto GO. • The rGO-Fc-NH2/AuNPs composite has good conductivity and compatibility. • The nanocomposite effectively prevent the electron mediator leaking from electrode. • A synergetic amplification platform to ultra-sensitive detect BPA was established. - Abstract: In this paper, a novel electro-active graphene oxide (GO) nanocomposite was firstly prepared by covalently grafted (4-ferrocenylethyne) phenylamine (Fc-NH2) onto the surface of GO. The synthesized hybridized nanocomposite of GO-Fc-NH2 coupled with HAuCl4 simultaneously electrodeposited on the glassy carbon electrodes (GCE) to obtain rGO-Fc-NH2/AuNPs/GCE. The covalently grafted material of the rGO-Fc-NH2/AuNPs film can effectively prevent the electron mediator leaking from the electrode surface, which can hold the advantage of both the nanomaterials and electron mediator. By employing the catalysis effect of the nanomaterial and electron mediator coupling with large active surface area and high accumulation capacity of rGO-Fc-NH2/AuNPs, a synergetic signal amplification platform for ultra-sensitive detection of bisphenol A (BPA) was successfully established. With this novel sensor, the oxidation peak currents of BPA were linearly dependent on the BPA concentrations in the range of 0.005–10 μM with the detection limit of 2 nM. Modification of electron mediators on nanomaterials can greatly enhance the electrochemical performance of the sensors and will provide a new concept for fabricating newly electro-active nanomaterials-based electrochemical biosensors

  9. Assembly and magneto-electrical characterization of hybrid organic-inorganic systems

    OpenAIRE

    Gang, Tian

    2011-01-01

    Organic building blocks are increasingly applied in current nanoelectronics research and development. In this thesis, the assembly and magneto-electrical characterization of several hybrid organic-inorganic magnetically active systems were described. Several molecular approaches were developed to assemble magnetic nanoparticles on various substrates with controllable density. This is considered as a step forward towards nanoparticle based hybrid spintronics devices. An electron interferometer...

  10. Nanoparticles in ionic liquids: interactions and organization.

    Science.gov (United States)

    He, Zhiqi; Alexandridis, Paschalis

    2015-07-28

    Ionic liquids (ILs), defined as low-melting organic salts, are a novel class of compounds with unique properties and a combinatorially great chemical diversity. Ionic liquids are utilized as synthesis and dispersion media for nanoparticles as well as for surface functionalization. Ionic liquid and nanoparticle hybrid systems are governed by a combined effect of several intermolecular interactions between their constituents. For each interaction, including van der Waals, electrostatic, structural, solvophobic, steric, and hydrogen bonding, the characterization and quantitative calculation methods together with factors affecting these interactions are reviewed here. Various self-organized structures based on nanoparticles in ionic liquids are generated as a result of a balance of these intermolecular interactions. These structures, including colloidal glasses and gels, lyotropic liquid crystals, nanoparticle-stabilized ionic liquid-containing emulsions, ionic liquid surface-functionalized nanoparticles, and nanoscale ionic materials, possess properties of both ionic liquids and nanoparticles, which render them useful as novel materials especially in electrochemical and catalysis applications. This review of the interactions within nanoparticle dispersions in ionic liquids and of the structure of nanoparticle and ionic liquid hybrids provides guidance on the rational design of novel ionic liquid-based materials, enabling applications in broad areas.

  11. Highly Elastic and Conductive Human-Based Protein Hybrid Hydrogels.

    Science.gov (United States)

    Annabi, Nasim; Shin, Su Ryon; Tamayol, Ali; Miscuglio, Mario; Bakooshli, Mohsen Afshar; Assmann, Alexander; Mostafalu, Pooria; Sun, Jeong-Yun; Mithieux, Suzanne; Cheung, Louis; Tang, Xiaowu Shirley; Weiss, Anthony S; Khademhosseini, Ali

    2016-01-01

    A highly elastic hybrid hydrogel of methacryloyl-substituted recombinant human tropoelastin (MeTro) and graphene oxide (GO) nanoparticles are developed. The synergistic effect of these two materials significantly enhances both ultimate strain (250%), reversible rotation (9700°), and the fracture energy (38.8 ± 0.8 J m(-2) ) in the hybrid network. Furthermore, improved electrical signal propagation and subsequent contraction of the muscles connected by hybrid hydrogels are observed in ex vivo tests.

  12. Hybrid Semiconductor-Metal Nanorods as Photocatalysts.

    Science.gov (United States)

    Ben-Shahar, Yuval; Banin, Uri

    2016-08-01

    Semiconductor-metal hybrid nanoparticles manifest combined and often synergistic properties exceeding the functionality of the individual components, thereby opening up interesting opportunities for controlling their properties through the direct manipulation of their unique semiconductor-metal interface. Upon light absorption, these structures exhibit spatial charge separation across the semiconductor-metal junction. A significant and challenging application involves the use of these nanoparticles as photocatalysts. Through this process, the charge carriers transferred to the metal co-catalyst are available as reduction or oxidation reagents to drive the surface chemical reactions. In this review, we discuss synthesis approaches that offer a high degree of control over the hybrid nanoparticle structure and composition, the number of catalytic sites and the interfacial characteristics, including examples of a variety of photocatalyst architectures. We describe the structural and surface effects with regard to the functionality of hybrid nanosystems in photocatalysis, along with the effects of solution and chemical conditions on photocatalytic activity and efficiency. We conclude with a perspective on the rational design of advanced semiconductor-metal hybrid nanoparticles towards their functionality as highly efficient photocatalysts. PMID:27573406

  13. Hybrid Amyloid Membranes for Continuous Flow Catalysis.

    Science.gov (United States)

    Bolisetty, Sreenath; Arcari, Mario; Adamcik, Jozef; Mezzenga, Raffaele

    2015-12-29

    Amyloid fibrils are promising nanomaterials for technological applications such as biosensors, tissue engineering, drug delivery, and optoelectronics. Here we show that amyloid-metal nanoparticle hybrids can be used both as efficient active materials for wet catalysis and as membranes for continuous flow catalysis applications. Initially, amyloid fibrils generated in vitro from the nontoxic β-lactoglobulin protein act as templates for the synthesis of gold and palladium metal nanoparticles from salt precursors. The resulting hybrids possess catalytic features as demonstrated by evaluating their activity in a model catalytic reaction in water, e.g., the reduction of 4-nitrophenol into 4-aminophenol, with the rate constant of the reduction increasing with the concentration of amyloid-nanoparticle hybrids. Importantly, the same nanoparticles adsorbed onto fibrils surface show improved catalytic efficiency compared to the same unattached particles, pointing at the important role played by the amyloid fibril templates. Then, filter membranes are prepared from the metal nanoparticle-decorated amyloid fibrils by vacuum filtration. The resulting membranes serve as efficient flow catalysis active materials, with a complete catalytic conversion achieved within a single flow passage of a feeding solution through the membrane.

  14. Nanoparticle diffraction gratings for DNA detection on photopatterned glass substrates

    OpenAIRE

    Sendroiu, Luliana E; Corn, Robert M.

    2008-01-01

    An ex situ nanoparticle DNA detection assay utilizing DNA-modified nanoparticles attached to DNA monolayer gratings on glass substrates is developed. The assay utilizes the simultaneous hybridization of a single stranded DNA (ssDNA) target molecule to both an amine-modified DNA oligonucleotide attached to an amine-reactive glass surface and a thiol-modified DNA oligonucleotide attached to a 13 nm gold nanoparticle. Surface plasmon resonance imaging measurements are used to characterize the tw...

  15. Application of chitosan-gold nanoparticles hybrid film biosensor in glucose measurement%壳聚糖和纳米金混合膜生物传感器在葡萄糖检测中的应用

    Institute of Scientific and Technical Information of China (English)

    吴国权; 李忠彦

    2009-01-01

    背景:目前只有通过控制血糖浓度的方法来控制糖尿病发病率,因此创建一种快速、稳定、精确测定血糖浓度的方法成为研究者关注的焦点.目的:观察壳聚糖和纳米金混合膜在电化学葡萄糖传感器中的作用.设计、时间、地点:观察实验,于2009-02/04在解放军广州军区广州总医院医学实验科内完成.材料:将CHIT/AuNPs膜电镀到金电极表面,利用戊二醛交联固定葡萄糖氧化酶,制得葡萄糖传感器.方法:以K3Fe(CN)6为探针离子,采用三电极循环伏安法考察了传感器的组装特性及电催化活性,通过线性扫描伏安法考察了传感器对葡萄糖的响应特性,并对实验条件进行了优化及稳定性与重复性进行考察.主要观察指标:不同修饰电极的循环伏安特性,葡萄糖浓度和响应电流的关系.结果:在0.001~6 mmol/L范围内,葡萄糖浓度和响应峰电流成线性关系.且该传感器具有操作简便,响应速度快(<2 s),重复性及稳定性好,检出限低(26.56 μmol/L),抗干扰能力强等优点.结论:以壳聚糖和纳米金混合膜材料研制的葡萄糖传感器具有好的重复性及稳定性,并且对葡萄糖的响应速度快,评测结果为可以应用于临床.%BACKGROUND:At present,syndromes happening frequency of diabetes mellitus can be controlled through regulating glucose concentration in blood.Therefore,a fast,steady,accurate glucose biosensor has been an intense area of focus for investigators.OBJECTIVE:To observe the effect of chitosan-gold nanoparticles hybrid film on electrochemical glucose biosensor.DESIGN,TIME AND SETTING:The observation experiment was performed at the Department of Medicine Laboratory,General Hospital,Guangzhou Military Command of Chinese PLA from February to April 2009.MATERIALS:Based on the immobilization of glucose oxidase (GOD) with cross-linking in the matrix of chitosan on an Au electrode by glutaraldehyde,a novel glucose biosensor was

  16. Hybrid Metaheuristics

    CERN Document Server

    2013-01-01

    The main goal of this book is to provide a state of the art of hybrid metaheuristics. The book provides a complete background that enables readers to design and implement hybrid metaheuristics to solve complex optimization problems (continuous/discrete, mono-objective/multi-objective, optimization under uncertainty) in a diverse range of application domains. Readers learn to solve large scale problems quickly and efficiently combining metaheuristics with complementary metaheuristics, mathematical programming, constraint programming and machine learning. Numerous real-world examples of problems and solutions demonstrate how hybrid metaheuristics are applied in such fields as networks, logistics and transportation, bio-medical, engineering design, scheduling.

  17. Hybrid intermediaries

    OpenAIRE

    Cetorelli, Nicola

    2014-01-01

    I introduce the concept of hybrid intermediaries: financial conglomerates that control a multiplicity of entity types active in the "assembly line" process of modern financial intermediation, a system that has become known as shadow banking. The complex bank holding companies of today are the best example of hybrid intermediaries, but I argue that financial firms from the "nonbank" space can just as easily evolve into conglomerates with similar organizational structure, thus acquiring the cap...

  18. Synthesis and characterization of magnetic cobalt ferrite nanoparticles covered with 3-aminopropyltriethoxysilane for use as hybrid material in nano technology; Sintese e caracterizacao de nanoparticulas magneticas de ferrita de cobalto recobertas por 3-aminopropiltrietoxissilano para uso como material hibrido em nanotecnologia

    Energy Technology Data Exchange (ETDEWEB)

    Camilo, Ruth Luqueze

    2006-07-01

    Nowadays with the appear of nano science and nano technology, magnetic nanoparticles have been finding a variety of applications in the fields of biomedicine, diagnosis, molecular biology, biochemistry, catalysis, etc. The magnetic functionalized nanoparticles are constituted of a magnetic nucleus, involved by a polymeric layer with active sites, which ones could anchor metals or selective organic compounds. These nanoparticles are considered organic inorganic hybrid materials and have great interest as materials for commercial applications due to the specific properties. Among the important applications it can be mentioned: magneto hyperthermia treatment, drugs delivery in specific local of the body, molecular recognition, biosensors, enhancement of nuclear magnetic resonance images quality, etc. This work was developed in two parts: 1) the synthesis of the nucleus composed by superparamagnetic nanoparticles of cobalt ferrite and, 2) the recovering of nucleus by a polymeric bifunctional 3-aminopropyltriethoxysilane. The parameters studied in the first part of the research were: pH, hydroxide molar concentration, hydroxide type, reagent order of addition, reagent way of addition, speed of shake, metals initial concentrations, molar fraction of cobalt and thermal treatment. In the second part it was studied: pH, temperature, catalyst type, catalyst concentration, time of reaction, relation ratios of H{sub 2}O/silane, type of medium and the efficiency of the recovering regarding to pH. The products obtained were characterized using the following techniques X-ray powder diffraction (DRX), transmission electronic microscopy (TEM), scanning electronic microscopy (SEM), spectroscopy of scatterbrained energy spectroscopy (DES), atomic emission spectroscopy (ICP-AES), thermogravimetric analysis (TGA/DTGA), Fourier transform infrared spectroscopy (FTIR), differential scanning calorimetry (DSC) and magnetization curves (VSM). (author)

  19. Monovalent plasmonic nanoparticles for biological applications

    Science.gov (United States)

    Seo, Daeha; Lee, Hyunjung; Lee, Jung-uk; Haas, Thomas J.; Jun, Young-wook

    2016-03-01

    The multivalent nature of commercial nanoparticle imaging agents and the difficulties associated with producing monovalent nanoparticles challenge their use in biology, where clustering of target biomolecules can perturb dynamics of biomolecular targets. Here, we report production and purification of monovalent gold and silver nanoparticles for their single molecule imaging application. We first synthesized DNA-conjugated 20 nm and 40 nm gold and silver nanoparticles via conventional metal-thiol chemistry, yielding nanoparticles with mixed valency. By employing an anion-exchange high performance liquid chromatography (AE-HPLC) method, we purified monovalent nanoparticles from the mixtures. To allow efficient peak-separation resolution while keeping the excellent colloidal stability of nanoparticles against harsh purification condition (e.g. high NaCl), we optimized surface properties of nanoparticles by modulating surface functional groups. We characterized the monovalent character of the purified nanoparticles by hybridizing two complementary conjugates, forming dimers. Finally, we demonstrate the use of the monovalent plasmonic nanoprobes as single molecule imaging probes by tracking single TrkA receptors diffusing on the cell membrane and compare to monovalent quantum dot probes.

  20. Nanoporous hybrid electrolytes

    KAUST Repository

    Schaefer, Jennifer L.

    2011-01-01

    Oligomer-suspended SiO2-polyethylene glycol nanoparticles are studied as porous media electrolytes. At SiO2 volume fractions, , bracketing a critical value y ≈ 0.29, the suspensions jam and their mechanical modulus increase by more than seven orders. For >y, the mean pore diameter is close to the anion size, yet the ionic conductivity remains surprisingly high and can be understood, at all , using a simple effective medium model proposed by Maxwell. SiO 2-polyethylene glycol hybrid electrolytes are also reported to manifest attractive electrochemical stability windows (0.3-6.3 V) and to reach a steady-state interfacial impedance when in contact with metallic lithium. © 2010 The Royal Society of Chemistry.

  1. Intermetallic nanoparticles

    Science.gov (United States)

    Singh, Dileep; Yusufoglu, Yusuf; Timofeeva, Elena; Routbort, Jules

    2015-07-14

    A process for preparing intermetallic nanoparticles of two or more metals is provided. In particular, the process includes the steps: a) dispersing nanoparticles of a first metal in a solvent to prepare a first metal solution, b) forming a reaction mixture with the first metal solution and a reducing agent, c) heating the reaction mixture to a reaction temperature; and d) adding a second metal solution containing a salt of a second metal to the reaction mixture. During this process, intermetallic nanoparticles, which contain a compound with the first and second metals are formed. The intermetallic nanoparticles with uniform size and a narrow size distribution is also provided. An electrochemical device such as a battery with the intermetallic nanoparticles is also provided.

  2. METALLIC AND HYBRID NANOSTRUCTURES: FUNDAMENTALS AND APPLICATIONS

    Energy Technology Data Exchange (ETDEWEB)

    Murph, S.

    2012-05-02

    This book chapter presents an overview of research conducted in our laboratory on preparation, optical and physico-chemical properties of metallic and nanohybrid materials. Metallic nanoparticles, particularly gold, silver, platinum or a combination of those are the main focus of this review manuscript. These metallic nanoparticles were further functionalized and used as templates for creation of complex and ordered nanomaterials with tailored and tunable structural, optical, catalytic and surface properties. Controlling the surface chemistry on/off metallic nanoparticles allows production of advanced nanoarchitectures. This includes coupled or encapsulated core-shell geometries, nano-peapods, solid or hollow, monometallic/bimetallic, hybrid nanoparticles. Rational assemblies of these nanostructures into one-, two- and tridimensional nano-architectures is described and analyzed. Their sensing, environmental and energy related applications are reviewed.

  3. Fast, single-step, and surfactant-free oligonucleotide modification of gold nanoparticles using DNA with a positively charged tail

    NARCIS (Netherlands)

    Gill, R.; Goeken, K.; Subramaniam, V.

    2013-01-01

    Fast modification of large gold nanoparticles with DNA is achieved by using DNA with a polycationic tail. The conjugated DNA is available for specific hybridization, and therefore can be used for DNA-based assays or for constructing nanoparticle superstructures based on DNA hybridization.

  4. Dual-responsive mPEG-PLGA-PGlu hybrid-core nanoparticles with a high drug loading to reverse the multidrug resistance of breast cancer: an in vitro and in vivo evaluation.

    Science.gov (United States)

    Xu, Helin; Yang, Dan; Cai, Cuifang; Gou, Jingxin; Zhang, Yu; Wang, Lihui; Zhong, Haijun; Tang, Xing

    2015-04-01

    In this study, monomethoxy (polyethylene glycol)-b-P (d,l-lactic-co-glycolic acid)-b-P (l-glutamic acid) (mPEG-PLGA-PGlu) nanoparticles with the ability to rapidly respond to the endolysosomal pH and hydrolase were prepared and the pH-sensitivity was tuned by adjusting the length of the PGlu segment. The mPEG5k-PLGA20k-PGlu (60) nanoparticles were specifically responsive to an endosomal pH of 5.0-6.0 due to the configuration transition of the PGlu segment and rapidly initiated chemical degradation after incubation with proteinase k for 10 min. Doxorubicin hydrochloride (DOX), used as a model drug, was easily encapsulated into nanoparticles and the DOX-loaded nanoparticles (DOX-NPs) exhibited a pH-dependent and enzyme-sensitive release profile in vitro. The dual sensitivity enabled the rapid escape of DOX-loaded nanoparticles from the endolysosomal system to target cellular nuclei, which resulted in increased cell toxicity against MCF/ADR resistant breast cancer cells and a higher cellular uptake than free DOX. In Vivo Imaging studies indicated that the nanoparticles could continuously accumulate in the tumor tissues through EPR effects and Ex vivo Imaging biodistribution studies indicated that DOX-NPs increased drug penetration into tumors compared with normal tissues. The in vivo antitumor activity demonstrated that DOX-loaded NPs had less body loss and a significant regression of tumor growth, indicating the increased anti-tumor efficacy and lower systemic toxicity. Therefore, this dual sensitive nanoparticle system may be a potential nanocarrier to overcome the multidrug resistance exhibited by breast cancer.

  5. Hybride betongkonstruksjoner

    OpenAIRE

    Bjerve, Tor Øystein

    2010-01-01

    Denne oppgaven tar for seg beregning og testing av hybride betongkonstruksjoner. Den inneholder også beskrivelse av materialtester. Bjelkene som testes er tenkt å være utsnitt av dekkekonstruksjoner. Konstruksjonene skal bestå av et lag fiberarmert lettbetong, som er tenkt å opptre som en prefabrikert betongforskaling, samt en påstøp som kan fungere som ferdig gulv.I teoridelen av oppgaven er det sett på utfordringer og fordeler ved å benytte hybride konstruksjoner. I tillegg er beregningsvei...

  6. Counting Single Rhodamine 6G Dye Molecules in Organosilicate Nanoparticles

    OpenAIRE

    Trenkmann, I.; Bok, S.; Korampally, V.; S. Gangopadhyay; Graaf, H. de; C. von Borczyskowski

    2012-01-01

    Rhodamine 6G (R6G) dye molecules have been embedded into organosilicate nanoparticles to improve thermal and chemical stability of these marker molecules. We demonstrate that the well-established method of optical single-particle microscopy can be used to determine the number of dye molecules per nanoparticle in such hybrid materials. Analysing the fluorescence intensity of R6G in single nanoparticles, we obtain an average number of 1.3 – 1.7 dye molecules per nanoparticle as compared to 1 R6...

  7. The detection of HBV DNA with gold nanoparticle gene probes

    Institute of Scientific and Technical Information of China (English)

    Dong Xi; Xiaoping Luo; Qin Ning; Qianghua Lu; Kailun Yao; Zuli Liu

    2007-01-01

    Objective:Gold nanoparticle Hepatitis B virus (HBV) DNA probes were prepared, and their application for HBV DNA measurement was studied. Methods:Alkanethiol modified oligonucleotide was bound with self-made Au nanoparticles to form nanoparticle HBV DNA gene probes, through covalent binding of Au-S. By using a fluorescence-based method, the number of thiol-derivatized, single-stranded oligonucleotides and their hybridization efficiency with complementary oligonucleotides in solution was determined. With the aid of Au nanoparticle-supported mercapto-modified oligonucleotides serving as detection probes, and oligonucleotides immobilized on a nylon membrane surface acting as capturing probes,HBV DNA was detected visually by sandwich hybridization based on highly sensitive aggregation and silver staining. The modified nanoparticle HBV DNA gene probes were also used to detect the HBV DNA extracted from serum in patients with hepatitis B. Results:Compared with bare Au nanoparticles, oligonucleotide modified nanoparticles had a higher stability in NaCl solution or under high temperature environment and the absorbance peak of modified Au nanoparticles shifted from 520nm to 524nm. For Au nanoparticles, the maximal oligonucleotide surface coverage of hexaethiol 30-mer oligonucleotide was (132 ± 10) oligonucleotides per nanoparticle, and the percentage of hybridization strands on nanoparticles was (22 ± 3% ). Based on a two-probe sandwich hybridization/nanoparticle amplification/silver staining enhancement method, Au nanoparticle gene probes could detect as low as 10-11 mol/L composite HBV DNA molecules on a nylon membrane and the PCR products of HBV DNA visually. As made evident by transmission electron microscopy, the nanoparticles assembled into large network aggregates when nanoparticle HBV DNA gene probes were applied to detect HBV DNA molecules in liquid. Conclusion:Our results showed that successfully prepared Au nanoparticle HBV DNA gene probes could be used to

  8. Probing Compositional Variation within Hybrid Nanostructures

    Energy Technology Data Exchange (ETDEWEB)

    Yuhas, Benjamin D.; Habas, Susan E.; Fakra, Sirine C.; Mokari, Taleb

    2010-06-22

    We present a detailed analysis of the structural and magnetic properties of solution-grown PtCo-CdS hybrid structures in comparison to similar free-standing PtCo alloy nanoparticles. X-ray absorption spectroscopy is utilized as a sensitive probe for identifying subtle differences in the structure of the hybrid materials. We found that the growth of bimetallic tips on a CdS nanorod substrate leads to a more complex nanoparticle structure composed of a PtCo alloy core and thin CoO shell. The core-shell architecture is an unexpected consequence of the different nanoparticle growth mechanism on the nanorod tip, as compared to free growth in solution. Magnetic measurements indicate that the PtCo-CdS hybrid structures are superparamagnetic despite the presence of a CoO shell. The use of X-ray spectroscopic techniques to detect minute differences in atomic structure and bonding in complex nanosystems makes it possible to better understand and predict catalytic or magnetic properties for nanoscale bimetallic hybrid materials.

  9. Antibody-Conjugated Nanoparticles for Biomedical Applications

    Directory of Open Access Journals (Sweden)

    Manuel Arruebo

    2009-01-01

    Full Text Available Nanoscience and Nanotechnology have found their way into the fields of Biotechnology and Medicine. Nanoparticles by themselves offer specific physicochemical properties that they do not exhibit in bulk form, where materials show constant physical properties regardless of size. Antibodies are nanosize biological products that are part of the specific immune system. In addition to their own properties as pathogens or toxin neutralizers, as well as in the recruitment of immune elements (complement, improving phagocytosis, cytotoxicity antibody dependent by natural killer cells, etc., they could carry several elements (toxins, drugs, fluorochroms, or even nanoparticles, etc. and be used in several diagnostic procedures, or even in therapy to destroy a specific target. The conjugation of antibodies to nanoparticles can generate a product that combines the properties of both. For example, they can combine the small size of nanoparticles and their special thermal, imaging, drug carrier, or magnetic characteristics with the abilities of antibodies, such as specific and selective recognition. The hybrid product will show versatility and specificity. In this review, we analyse both antibodies and nanoparticles, focusing especially on the recent developments for antibody-conjugated nanoparticles, offering the researcher an overview of the different applications and possibilities of these hybrid carriers.

  10. Hybrid Qualifications

    DEFF Research Database (Denmark)

    has turned out as a major focus of European education and training policies and certainly is a crucial principle underlying the European Qualifications Framework (EQF). In this context, «hybrid qualifications» (HQ) may be seen as an interesting approach to tackle these challenges as they serve «two...

  11. A Kirchhoff solution to plasmon hybridization

    Science.gov (United States)

    Willingham, Britain; Link, Stephan

    2013-12-01

    Using Ohm's law, a solution to plasmon hybridization via Kirchoff's equations results in a simple and intuitive picture of a metal nanoparticle dimer as a capacitively coupled circuit. Calculated absorption spectra and surface charge densities show that dimers of different metallic composition support different super- and sub-radiant plasmons compared to homodimers. Strong screening of Coulomb interactions between nanoparticles of different metallic background prohibits the excitation of anti-bonding plasmons, while changes to the free electron conductivity upon a collective response result in coupled plasmon lifetimes which shift as a function of interparticle distance. Smaller separations then result in the longest lived plasmons.

  12. Synthesis of AgCI nanoparticles in ionic liquid microemulsion and pervaporation of AgCl/poly ( MMA- co- AM) hybrid membranes%离子液体微乳液中纳米AgCl的合成及AgCl/poly(MMA—co—AM)杂化膜的渗透汽化分离

    Institute of Scientific and Technical Information of China (English)

    滕燕; 王挺; 杜春慧; 吴礼光

    2012-01-01

    以离子液体氯化-1-十二烷基甲基咪唑(C12 mimCl)为表面活性剂,甲基丙烯酸甲酯(MMA)和丙烯酰胺(AM)混合物为油相构筑的反相微乳液合成AgCl纳米粒子。通过微乳液聚合制备AgCl/poly(MMA—co—AM)杂化膜,用于苯-环己烷混合物的渗透汽化分离。利用紫外-可见吸收光谱(UV—Vis)和透射电镜(TEM)分析AgCl纳米粒子的形貌及结构,利用XRD和SEM分析了杂化膜中AgCl粒子的形貌及结构,通过杂化膜的苯-环已烷混合物(质量分数50%,30℃)的渗透汽化实验分析了杂化膜的分离性能。结果表明:纳米AgCl粒子的平均粒径和粒子数随微乳液中AgNO3浓度(CAgNO3)的增大明显增加;增加微乳液中C122mimCl浓度(CC12mimCl),有利于形成数量较多、平均粒径较小的纳米AgCl粒子;AgCl/poly(MMA—co—AM)杂化膜中AgCl粒子粒径较小,且均匀分散于poly(MMA—co—AM)基材中;随着CAgNO3的增加,杂化膜的渗透通量明显增大,分离因子先增大后减小;而随CC12mimCl的增加,杂化膜的分离因子持续增大,渗透通量表现出先增大后减小的趋势;杂化膜的分离因子最高可达5.0,渗透通量约为490g·m^-2·h^-1,表现出较好的分离性能。%Nanoparticles of AgCl were synthesized in W/O reverse microemulsion using ionic liquid 1 - dodecyl - 3 -methyl imidazoium chloride(Cl2mimCl) as surfactant, methyl methacrylate(MMA)-acrylamide(AM) mixture as oil phase. And then AgCl/poly(MMA-co-AM) hybrid membranes were prepared by microemulsion polymerization for separation of benzenecyclohexane (mass fraction 50%) mixture by pervaporation at 30 ℃. The effect of concentration of surfactant (CC12mimCl) and salt (CAgNO3 ) on formation and morphology of AgCl nanoparticles were studied by ultravioletvisible spectrum and transmission electron microscopy(TEM). The structures of hybrid membranes were characterized by XRD and

  13. Hybrid plasmonic devices for sensing and thermal imaging

    OpenAIRE

    Tittl, Andreas

    2015-01-01

    Plasmonics is an emerging field in nanooptics, which focuses on the optical properties of resonant subwavelength metal nanoparticles. Historically, such geometries commonly employed noble metal nanoparticles to achieve a variety of effects ranging from nanofocusing of light to negative refraction. Building on these concepts, this thesis investigates hybrid nanoplasmonic devices, which combine passive noble metal nanostructures with chemically reactive or actively tunable materials to obtain n...

  14. Hybrid microelectronic technology

    Science.gov (United States)

    Moran, P.

    Various areas of hybrid microelectronic technology are discussed. The topics addressed include: basic thick film processing, thick film pastes and substrates, add-on components and attachment methods, thin film processing, and design of thick film hybrid circuits. Also considered are: packaging hybrid circuits, automating the production of hybrid circuits, application of hybrid techniques, customer's view of hybrid technology, and quality control and assurance in hybrid circuit production.

  15. Multifunctional Graphene/Platinum/Nafion Hybrids via Ice Templating

    KAUST Repository

    Estevez, Luis

    2011-04-27

    We report the synthesis of multifunctional hybrids in both films and bulk form, combining electrical and ionic conductivity with porosity and catalytic activity. The hybrids are synthesized by a two-step process: (a) ice templation of an aqueous suspension comprised of Nafion, graphite oxide, and chloroplatinic acid to form a microcellular porous network and (b) mild reduction in hydrazine or monosodium citrate which leads to graphene-supported Pt nanoparticles on a Nafion scaffold. © 2011 American Chemical Society.

  16. Hybrid dextran-iron oxide thin films deposited by laser techniques for biomedical applications

    OpenAIRE

    Predoi, Daniela; Ciobanu, Carmen Steluta; Mihaela RADU; COSTACHE, MARIETA; Dinischiotu, Anca; Gyorgy, Eniko

    2012-01-01

    Iron oxide nanoparticles were prepared by chemical co-precipitation method. The nanoparticles were mixed with dextran in distilled water. The obtained solutions were frozen in liquid nitrogen and used as targets during matrix assisted pulsed laser evaporation for the growth of hybrid, iron oxide nanoparticles-dextran thin films. Fourier Transform Infrared Spectroscopy and X-ray diffraction investigations revealed that the obtained films preserve the structure and composition of the initial, n...

  17. Biopolymeric nanoparticles

    Directory of Open Access Journals (Sweden)

    Sushmitha Sundar, Joydip Kundu and Subhas C Kundu

    2010-01-01

    Full Text Available This review on nanoparticles highlights the various biopolymers (proteins and polysaccharides which have recently revolutionized the world of biocompatible and degradable natural biological materials. The methods of their fabrication, including emulsification, desolvation, coacervation and electrospray drying are described. The characterization of different parameters for a given nanoparticle, such as particle size, surface charge, morphology, stability, structure, cellular uptake, cytotoxicity, drug loading and drug release, is outlined together with the relevant measurement techniques. Applications in the fields of medicine and biotechnology are discussed along with a promising future scope.

  18. Biomedical Applications of Advanced Multifunctional Magnetic Nanoparticles.

    Science.gov (United States)

    Long, Nguyen Viet; Yang, Yong; Teranishi, Toshiharu; Thi, Cao Minh; Cao, Yanqin; Nogami, Masayuki

    2015-12-01

    In this review, we have presented the latest results and highlights on biomedical applications of a class of noble metal nanoparticles, such as gold, silver and platinum, and a class of magnetic nanoparticles, such as cobalt, nickel and iron. Their most important related compounds are also discussed for biomedical applications for treating various diseases, typically as cancers. At present, both physical and chemical methods have been proved very successful to synthesize, shape, control, and produce metal- and oxide-based homogeneous particle systems, e.g., nanoparticles and microparticles. Therefore, we have mainly focused on functional magnetic nanoparticles for nanomedicine because of their high bioadaptability to the organs inside human body. Here, bioconjugation techniques are very crucial to link nanoparticles with conventional drugs, nanodrugs, biomolecules or polymers for biomedical applications. Biofunctionalization of engineered nanoparticles for biomedicine is shown respective to in vitro and in vivo analysis protocols that typically include drug delivery, hyperthermia therapy, magnetic resonance imaging (MRI), and recent outstanding progress in sweep imaging technique with Fourier transformation (SWIFT) MRI. The latter can be especially applied using magnetic nanoparticles, such as Co-, Fe-, Ni-based nanoparticles, α-Fe2O3, and Fe3O4 oxide nanoparticles for analysis and treatment of malignancies. Therefore, this review focuses on recent results of scientists, and related research on diagnosis and treatment methods of common and dangerous diseases by biomedical engineered nanoparticles. Importantly, nanosysems (nanoparticles) or microsystems (microparticles) or hybrid micronano systems are shortly introduced into nanomedicine. Here, Fe oxide nanoparticles ultimately enable potential and applicable technologies for tumor-targeted imaging and therapy. Finally, we have shown the latest aspects of the most important Fe-based particle systems, such as Fe,

  19. Functional Films from Silica/Polymer Nanoparticles

    Directory of Open Access Journals (Sweden)

    Tânia Ribeiro

    2014-05-01

    Full Text Available High performance functional coatings, based on hybrid organic/inorganic materials, are being developed to combine the polymer flexibility and ease of processing with the mechanical properties and versatility of inorganic materials. By incorporating silica nanoparticles (SiNPs in the polymeric matrices, it is possible to obtain hybrid polymer films with increased tensile strength and impact resistance, without decreasing the flexural properties of the polymer matrix. The SiNPs can further be used as carriers to impart other functionalities (optical, etc. to the hybrid films. By using polymer-coated SiNPs, it is possible to reduce particle aggregation in the films and, thus, achieve more homogeneous distributions of the inorganic components and, therefore, better properties. On the other hand, by coating polymer particles with silica, one can create hierarchically structured materials, for example to obtain superhydrophobic coatings. In this review, we will cover the latest developments in films prepared from hybrid polymer/silica functional systems.

  20. Photoelectrochemical glucose biosensor incorporating CdS nanoparticles

    Institute of Scientific and Technical Information of China (English)

    Jinjie Sun; Yihua Zhu; Xiaoling Yang; Chunzhong Li

    2009-01-01

    A novel photoelectrochemical biosensor incorporating nanosized CdS semiconductor crystals with enzyme to enhance photochemical reaction has been investigated. CdS nanoparticles were synthesized by using dendrimer PAMAM as inner templates. The CdS nanoparticles and glucose oxidase (GOD) were immobilized on Pt electrode via layer-by-layer (LbL) technique to fabricate a biological-inorganic hybrid system. Under ultraviolet light, the photo-effect of the CdS nanoparticles showed enhancement of the biosensor to detect glucose. Pt nanoparticles were mixed into the Nation film to immobilize the CdS/enzyme composites and to improve the charge transfer of the hybrid, Experimental results demonstrate the desirable characteristics of this biosensing system, e.g. a sensitivity of 1.83 μA/(mM cm~2), lower detection limit (1 μM), and acceptable reproducibility and stability.

  1. Hybrid Qualifications

    DEFF Research Database (Denmark)

    has turned out as a major focus of European education and training policies and certainly is a crucial principle underlying the European Qualifications Framework (EQF). In this context, «hybrid qualifications» (HQ) may be seen as an interesting approach to tackle these challenges as they serve «two...... masters», i.e. by producing skills for the labour market and enabling individuals to progress more or less directly to higher education. The specific focus of this book is placed on conditions, structures and processes which help to combine VET with qualifications leading into higher education...

  2. Synthesis and properties of core–shell fluorescent hybrids with distinct morphologies based on carbon dots

    KAUST Repository

    Markova, Zdenka

    2012-01-01

    Fluorescent core-shell nanohybrids with the shells derived from carbon dots and cores differing in the chemical nature and morphology were synthesized. Hybrid nanoparticles combine fluorescence with other functionalities such as magnetic response on a single platform. These hybrids can be used in various bioapplications as demonstrated with labeling of stem cells. © The Royal Society of Chemistry 2012.

  3. Label-free DNA biosensor based on resistance change of platinum nanoparticles assemblies.

    Science.gov (United States)

    Skotadis, Evangelos; Voutyras, Konstantinos; Chatzipetrou, Marianneza; Tsekenis, Georgios; Patsiouras, Lampros; Madianos, Leonidas; Chatzandroulis, Stavros; Zergioti, Ioanna; Tsoukalas, Dimitris

    2016-07-15

    A novel nanoparticle based biosensor for the fast and simple detection of DNA hybridization events is presented. The sensor utilizes hybridized DNA's charge transport properties, combining them with metallic nanoparticle networks that act as nano-gapped electrodes. The DNA hybridization events can be detected by a significant reduction in the sensor's resistance due to the conductive bridging offered by hybridized DNA. By modifying the nanoparticle surface coverage, which can be controlled experimentally being a function of deposition time, and the structural properties of the electrodes, an optimized biosensor for the in situ detection of DNA hybridization events is ultimately fabricated. The fabricated biosensor exhibits a wide response range, covering four orders of magnitude, a limit of detection of 1nM and can detect a single base pair mismatch between probe and complementary DNA. PMID:26995284

  4. Intuitionistic hybrid logic

    DEFF Research Database (Denmark)

    Braüner, Torben

    2011-01-01

    Intuitionistic hybrid logic is hybrid modal logic over an intuitionistic logic basis instead of a classical logical basis. In this short paper we introduce intuitionistic hybrid logic and we give a survey of work in the area....

  5. Polyelectrolyte complex nanoparticles from cationised gelatin and sodium alginate for curcumin delivery.

    Science.gov (United States)

    Sarika, P R; James, Nirmala Rachel

    2016-09-01

    Self assembled hybrid polyelectrolyte complex (PEC) nanoparticles are prepared from cationically modified gelatin and sodium alginate (Alg) by electrostatic complexation between the polymers. Cationised gelatin (CG) is prepared by the reaction of gelatin with ethylenediamine. Structural changes in gelatin, after modification with ethylenediamine are investigated by XRD and (1)H NMR spectroscopy. Hybrid polyelectrolyte nanoparticles, labeled CG/Alg, are prepared by simple mixing of CG and Alg. CG/Alg complex shows spherical morphology as confirmed by scanning electron microscopy. These polyelectrolyte complex nanoparticles can be used for the encapsulation and delivery of natural antioxidant curcumin to carcinoma cells. CG/Alg nanoparticles show curcumin encapsulation efficiency of 69% and exhibit sustained release of curcumin in vitro. Anticancer activity of curcumin loaded CG/Alg nanoparticles towards MCF-7 cells is disclosed by MTT assay. Intracellular uptake of the drug encapsulated nanoparticles is confirmed by fluorescent imaging. PMID:27185149

  6. Continuity Controlled Hybrid Automata

    OpenAIRE

    Bergstra, J.A.; Middelburg, C. A.

    2004-01-01

    We investigate the connections between the process algebra for hybrid systems of Bergstra and Middelburg and the formalism of hybrid automata of Henzinger et al. We give interpretations of hybrid automata in the process algebra for hybrid systems and compare them with the standard interpretation of hybrid automata as timed transition systems. We also relate the synchronized product operator on hybrid automata to the parallel composition operator of the process algebra. It turns out that the f...

  7. Nanoscale Organic−Inorganic Hybrid Lubricants

    KAUST Repository

    Kim, Daniel

    2011-03-15

    Silica (SiO2) nanoparticles densely grafted with amphiphilic organic chains are used to create a family of organic-inorganic hybrid lubricants. Short sulfonate-functionalized alkylaryl chains covalently tethered to the particles form a dense corona brush that stabilizes them against aggregation. When these hybrid particles are dispersed in poly-α-olefin (PAO) oligomers, they form homogeneous nanocomposite fluids at both low and high particle loadings. By varying the volume fraction of the SiO2 nanostructures in the PAO nanocomposites, we show that exceptionally stable hybrid lubricants can be created and that their mechanical properties can be tuned to span the spectrum from simple liquids to complex gels. We further show that these hybrid lubricants simultaneously exhibit lower interfacial friction coefficients, enhanced wear and mechanical properties, and superior thermal stability in comparison with either PAO or its nanocomposites created at low nanoparticle loadings. Profilometry and energy dispersive X-ray spectroscopic analysis of the wear track show that the enhanced wear characteristics in PAO-SiO2 composite lubricants originate from two sources: localization of the SiO2 particles into the wear track and extension of the elastohydrodynamic lubrication regime to Sommerfeld numbers more than an order of magnitude larger than for PAO. © 2011 American Chemical Society.

  8. Substrate Size-Selective Catalysis with Zeolite-Encapsulated Gold Nanoparticles

    DEFF Research Database (Denmark)

    Laursen, Anders Bo; Højholt, Karen Thrane; Lundegaard, L.F.;

    2010-01-01

    The Dark Crystal: A hybrid material is reported that is comprised of 1-2 nm sized gold nanoparticles, accessible only through zeolite micropores in a silicalite-1 crystal, as shown by three-dimensional TEM tomography (see picture). Calcination experiments indicate that the embedded nanoparticles ...

  9. Doping silver nanoparticles in AOT lyotropic lamellarphases

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    The organic lyotropic liquid crystal with long-range structural order is used as templateto assemble inorganic/organic hybrid by doping pre-fabricated Ag nanoparticles. The lamellar hy-brid with both hydrophilic and hydrophobic particles doped simultaneously is realized for the firsttime. The change of template structure after doping and the stability origin of dual-doped systemare characterized by small angle X-ray scattering and polarized optical microscopy. Results showthat the interaction and space matching between surfactant bilayers and doped particles are

  10. A Novel Route for the Preparation of Gold Nanoparticles in Polycaprolactone Nanofibers

    OpenAIRE

    Simón Yobanny Reyes-López; Delfino Cornejo-Monroy; Gerardo González-García

    2015-01-01

    A facile strategy for the fabrication of polycaprolactone (PCL) nanofibers containing gold nanoparticles (AuNPs) is proposed. The method is based on electrospinning nanosuspensions loaded with passivated Au nanoparticles. The optical property of gold nanoparticles synthesized was observed by UV-visible absorption spectra. Morphology and structure of the Au-PCL hybrid nanofibers were characterized by scanning electron microscopy, scanning transmission electron microscopy, and Fourier transform...

  11. Nanoparticle Photoresists: Ligand Exchange as a New, Sensitive EUV Patterning Mechanism

    KAUST Repository

    Kryask, Marie

    2013-01-01

    Hybrid nanoparticle photoresists and their patterning using DUV, EUV, 193 nm lithography and e-beam lithography has been investigated and reported earlier. The nanoparticles have demonstrated very high EUV sensitivity and significant etch resistance compared to other standard photoresists. The current study aims at investigating and establishing the underlying mechanism for dual tone patterning of these nanoparticle photoresist systems. Infrared spectroscopy and UV absorbance studies supported by mass loss and dissolution studies support the current model. © 2013SPST.

  12. Covalent immobilization of oligoDNA on the surface of magnetic nanoparticles and surface-enhanced Raman scattering study

    Institute of Scientific and Technical Information of China (English)

    SHEN Hebai; WANG Youbao; YANG Haifeng; JIANG Jisen

    2003-01-01

    The DNA magnetic nanoparticles are potentially useful in isolating and purifying DNA or RNA, directing-target-medicines, the development of DNA biosensors and biochips. Surface functionalized magnetic nanoparticles with monodispersed shape and size were prepared by coating nano-sized γ-Fe2O3 with silica in reverse microemulsion, and then thiol-compounds were immobilized onto the magnetic nanoparticles. After immobilizing oligoDNA modified with thiol-disulfide on the surface of the fictionalized magnetic nanoparticles, we obtained DNA-magnetic nanoparticles. The efficiency of the single-linking probes loading at the surfaces of magnetic nanoparticles was examined via hybridization experiment. Surface-enhanced Raman scattering methods were also effectively applied to observing the immobilization and hybridization processes mentioned above. The results demonstrated oligoDNA being availably connected to the surface of the magnetic nanoparticles.

  13. Hybridized tetraquarks

    Science.gov (United States)

    Esposito, A.; Pilloni, A.; Polosa, A. D.

    2016-07-01

    We propose a new interpretation of the neutral and charged X , Z exotic hadron resonances. Hybridized-tetraquarks are neither purely compact tetraquark states nor bound or loosely bound molecules but rather a manifestation of the interplay between the two. While meson molecules need a negative or zero binding energy, its counterpart for h-tetraquarks is required to be positive. The formation mechanism of this new class of hadrons is inspired by that of Feshbach metastable states in atomic physics. The recent claim of an exotic resonance in the Bs0 π± channel by the D0 Collaboration and the negative result presented subsequently by the LHCb Collaboration are understood in this scheme, together with a considerable portion of available data on X , Z particles. Considerations on a state with the same quantum numbers as the X (5568) are also made.

  14. Hybridized tetraquarks

    Directory of Open Access Journals (Sweden)

    A. Esposito

    2016-07-01

    Full Text Available We propose a new interpretation of the neutral and charged X,Z exotic hadron resonances. Hybridized-tetraquarks are neither purely compact tetraquark states nor bound or loosely bound molecules but rather a manifestation of the interplay between the two. While meson molecules need a negative or zero binding energy, its counterpart for h-tetraquarks is required to be positive. The formation mechanism of this new class of hadrons is inspired by that of Feshbach metastable states in atomic physics. The recent claim of an exotic resonance in the Bs0π± channel by the D0 Collaboration and the negative result presented subsequently by the LHCb Collaboration are understood in this scheme, together with a considerable portion of available data on X,Z particles. Considerations on a state with the same quantum numbers as the X(5568 are also made.

  15. The effect of using hybrid nanomaterials on drying shrinkage and strength of cement pastes

    Directory of Open Access Journals (Sweden)

    Saaid I. Zaki

    2016-04-01

    Full Text Available The aim of this work is to study the effect of nanomaterials on the properties of cement paste, the experimental program included three parts: a- two types of nanosilica, locally produced NS1 and imported NS2, b- nanoclay (NC and c- Hybrid nanoparticles (NS1 & NC. In each part, cement paste was used with different percentages of nanoparticles. Compressive strength and drying shrinkage tests were applied in each part on the cured and uncured samples. The results showed that the compressive strength improved in the cement paste mixtures in the cured condition, the optimum percentages was 1% for NS1, 1% for NS2, 5% for NC, and 5% (0.5%NS1 & 4.5%NC for hybrid nanoparticles. The drying shrinkage increases with adding nanosilica and hybrid nanoparticles, while it decreases when adding NC.

  16. Functionalization of polydopamine coated magnetic nanoparticles with biological entities

    Science.gov (United States)

    Mǎgeruşan, Lidia; Mrówczyński, Radosław; Turcu, Rodica

    2015-12-01

    New hybrid materials, obtained through introduction of cysteine, lysine and folic acid as biological entities into polydopamine-coated magnetite nanoparticles, are reported. The syntheses are straight forward and various methods were applied for structural and morphological characterization of the resulting nanoparticles. XPS proved a very powerful tool for surface chemical analysis and it evidences the functionalization of polydopamine coated magnetite nanoparticles. The superparamagnetic behavior and the high values of saturation magnetization recommend all products for further application where magnetism is important for targeting, separation, or heating by alternative magnetic fields.

  17. Nanoparticles for Imaging, Sensing, and Therapeutic Intervention

    OpenAIRE

    Bogart, Lara K.; Puntes, Victor F.; Lévy, Raphaël

    2014-01-01

    Nanoparticles have the potential to contribute to new modalities in molecular imaging and sensing as well as in therapeutic interventions. In this Nano Focus article, we identify some of the current challenges and knowledge gaps that need to be confronted to accelerate the developments of various applications. Using specific examples, we journey from the characterization of these complex hybrid nanomaterials; continue with surface design and (bio)physicochemical properties, their fate in biol...

  18. Attachment of Gold Nanoparticles to Carbon Nanotubes

    Institute of Scientific and Technical Information of China (English)

    Xi Cheng MA; Ning LUN; Shu Lin WEN

    2005-01-01

    Carbon nanotubes were initially chemically modified with an H2SO4-HNO3 treatment,and subsequently activated with Pd-Sn catalytic nuclei via a one-step activation approach. These activated nanotubes were used as precursors for obtaining gold nanoparticles-attached nanotubes via simple electroless plating. This approach provides an efficient method for attachment of metal nanostructures to carbon nanotubes. Such novel hybrid nanostructures are attractive for many applications.

  19. Hybrid dextran-iron oxide thin films deposited by laser techniques for biomedical applications

    International Nuclear Information System (INIS)

    Iron oxide nanoparticles were prepared by chemical co-precipitation method. The nanoparticles were mixed with dextran in distilled water. The obtained solutions were frozen in liquid nitrogen and used as targets during matrix assisted pulsed laser evaporation for the growth of hybrid, iron oxide nanoparticles-dextran thin films. Fourier Transform Infrared Spectroscopy and X-ray diffraction investigations revealed that the obtained films preserve the structure and composition of the initial, non-irradiated iron oxide-dextran composite material. The biocompatibility of the iron oxide-dextran thin films was demonstrated by 3-(4.5 dimethylthiazol-2yl)-2.5-diphenyltetrazolium bromide-based colorimetric assay, using human liver hepatocellular carcinoma cells. - Highlights: ► Hybrid, dextran-iron oxide nanoparticles and thin films. ► Laser immobilization. ► Biocompatibility of dextran-iron oxide nanoparticles.

  20. Hybrid dextran-iron oxide thin films deposited by laser techniques for biomedical applications

    Energy Technology Data Exchange (ETDEWEB)

    Predoi, D.; Ciobanu, C.S. [National Institute for Physics of Materials, P.O. Box MG 07, Bucharest, Magurele (Romania); Radu, M.; Costache, M.; Dinischiotu, A. [Molecular Biology Center, University of Bucharest, 91-95 Splaiul Independentei, 76201, Bucharest 5 (Romania); Popescu, C.; Axente, E.; Mihailescu, I.N. [National Institute for Lasers, Plasma and Radiations Physics, P. O. Box MG 36, 77125 Bucharest (Romania); Gyorgy, E., E-mail: egyorgy@cin2.es [National Institute for Lasers, Plasma and Radiations Physics, P. O. Box MG 36, 77125 Bucharest (Romania); Consejo Superior de Investigaciones Cientificas, Centre d' Investigacions en Nanociencia i Nanotecnologia (CSIC-CIN2), Campus UAB, 08193 Bellaterra (Spain)

    2012-02-01

    Iron oxide nanoparticles were prepared by chemical co-precipitation method. The nanoparticles were mixed with dextran in distilled water. The obtained solutions were frozen in liquid nitrogen and used as targets during matrix assisted pulsed laser evaporation for the growth of hybrid, iron oxide nanoparticles-dextran thin films. Fourier Transform Infrared Spectroscopy and X-ray diffraction investigations revealed that the obtained films preserve the structure and composition of the initial, non-irradiated iron oxide-dextran composite material. The biocompatibility of the iron oxide-dextran thin films was demonstrated by 3-(4.5 dimethylthiazol-2yl)-2.5-diphenyltetrazolium bromide-based colorimetric assay, using human liver hepatocellular carcinoma cells. - Highlights: Black-Right-Pointing-Pointer Hybrid, dextran-iron oxide nanoparticles and thin films. Black-Right-Pointing-Pointer Laser immobilization. Black-Right-Pointing-Pointer Biocompatibility of dextran-iron oxide nanoparticles.

  1. Self-assembled gold nanochains hybrid based on insulin fibrils

    Energy Technology Data Exchange (ETDEWEB)

    Zhang Longgai; Gao Faming, E-mail: fmgao@ysu.edu.cn [Yanshan University, Department of Applied Chemistry (China)

    2012-05-15

    We reported a facile method for preparing self-assembly gold nanochains by using insulin fibrils as biotemplate in aqueous environment. The gold nanochains hybrid nanostructures, which are insulin fibrils coated by gold nanoparticles, can be fabricated by simply reducing the salt precursors using DMAB. By increasing the molar ratio between salt precursors and insulin, denser hybrid nanochains can be obtained, meanwhile the mean diameter of gold nanoparticles is changing from 8 to 10 nm and then to 12 nm. The fabricated gold nanochains hybrid had helix structure, which was confirmed by circular dichroism spectra. The hybrid nanostructures were also investigated by transmission electron microscope, atomic force microscope, Fourier transform infrared spectra, and UV-Visible spectroscopy. As the wire-like structure become denser, the suspensions show color-changing, corresponding to the surface plasmon resonance red shift, which is attributed to the increasing mean size of nanoparticles. Based on the characterizations, a hypothetic mechanism was suggested to describe the formation processing of hybrid gold nanochains.

  2. Continuity Controlled Hybrid Automata

    NARCIS (Netherlands)

    Bergstra, J.A.; Middelburg, C.A.

    2004-01-01

    We investigate the connections between the process algebra for hybrid systems of Bergstra and Middelburg and the formalism of hybrid automata of Henzinger et al. We give interpretations of hybrid automata in the process algebra for hybrid systems and compare them with the standard interpretation of

  3. Continuity controlled Hybrid Automata

    NARCIS (Netherlands)

    Bergstra, J.A.; Middelburg, C.A.

    2008-01-01

    We investigate the connections between the process algebra for hybrid systems of Bergstra and Middelburg and the formalism of hybrid automata of Henzinger et al. We give interpretations of hybrid automata in the process algebra for hybrid systems and compare them with the standard interpretation of

  4. Metal Oxide Nanoparticle Photoresists for EUV Patterning

    KAUST Repository

    Jiang, Jing

    2014-01-01

    © 2014SPST. Previous studies of methacrylate based nanoparticle have demonstrated the excellent pattern forming capability of these hybrid materials when used as photoresists under 13.5 nm EUV exposure. HfO2 and ZrO2 methacrylate resists have achieved high resolution (∼22 nm) at a very high EUV sensitivity (4.2 mJ/cm2). Further investigations into the patterning process suggests a ligand displacement mechanism, wherein, any combination of a metal oxide with the correct ligand could generate patterns in the presence of the suitable photoactive compound. The current investigation extends this study by developing new nanoparticle compositions with transdimethylacrylic acid and o-toluic acid ligands. This study describes their synthesis and patterning performance under 248 nm KrF laser (DUV) and also under 13.5 nm EUV exposures (dimethylacrylate nanoparticles) for the new resist compositions.

  5. Second harmonic generation spectroscopy on hybrid plasmonic/dielectric nanoantennas

    Institute of Scientific and Technical Information of China (English)

    Heiko Linnenbank; Yevgen Grynko; Jens F(o)rstner; Stefan Linden

    2016-01-01

    Plasmonic nanoantennas provide unprecedented opportunities to concentrate light fields in subwavelength-sized volumes.By placing a nonlinear dielectric nanoparticle in such a hot spot,one can hope to take advantage of beth the field enhancement provided by nanoantennas and the large,nonlinear optical susceptibility of dielectric nanoparticles.To test this concept,we combine gold gap nanoantennas with second-order,nonlinear zinc sulfide nanoparticles,and perform second harmonic generation (SHG) spectroscopy onthe combined hybrid dielectric/plasmonic nanoantennas as well as on the individual constituents.We find that SHG from the bare gold nanoantennas,even though it should be forbidden due to symmetry reasons,is several orders of magnitude larger than that of the bare zinc sulfide nanoparticles.Even stronger second harmonic signals are generated by the hybrid dielectric/plasmonic nanoantennas.Control experiments with nanoantennas containing linear lanthanum fluoride nanoparticles reveal;however,that the increased SHG efficiency of the hybrid dielectric/plasmonic nanoantennas does not depend on the nonlinear optical susceptibility of the dielectric nanoparticles but is an effect of the modification of the dielectric environment.The combination of a hybrid dielectric/plasmonic nanoantenna,which is only resonant for the incoming pump light field,with a second nanoantenna,which is resonant for the generated second harmonic light,allows for a further increase in the efficiency of SHG.As the second nanoantenna mediates the coupling of the second harmonic light to the far field,this double-resonant approach also provides us with control over the polarization of the generated light.

  6. Growth of gold nanoparticles at gelatin-silica bio-interfaces

    Science.gov (United States)

    Bensaid, Imen; Masse, Sylvie; Selmane, Mohamed; Fessi, Shemseddine; Coradin, Thibaud

    2016-01-01

    The growth of gold nanoparticles via chemical reduction of HAuCl4 dispersed in gelatin-silicate mixtures was studied. Gelatin leads to densely packed nanoparticles whereas open colloidal aggregates with tight boundaries are formed within silica. Within the bio-hybrid systems, gold species are located within the gelatin-silicate particles and/or within the gelatin phase, depending on the preparation conditions. These various localizations and their impact on the final nanoparticle structure are discussed considering attractive and repulsive electrostatic interactions existing between the three components. These data suggest that bio-hybrid systems are interesting and versatile interfaces to study crystallization processes in confined environments.

  7. Differential Hybrid Games

    OpenAIRE

    Platzer, André

    2015-01-01

    This article introduces differential hybrid games, which combine differential games with hybrid games. In both kinds of games, two players interact with continuous dynamics. The difference is that hybrid games also provide all the features of hybrid systems and discrete games, but only deterministic differential equations. Differential games, instead, provide differential equations with continuous-time game input by both players, but not the luxury of hybrid games, such as mode switches and d...

  8. Antimicrobial Polymers with Metal Nanoparticles

    Directory of Open Access Journals (Sweden)

    Humberto Palza

    2015-01-01

    Full Text Available Metals, such as copper and silver, can be extremely toxic to bacteria at exceptionally low concentrations. Because of this biocidal activity, metals have been widely used as antimicrobial agents in a multitude of applications related with agriculture, healthcare, and the industry in general. Unlike other antimicrobial agents, metals are stable under conditions currently found in the industry allowing their use as additives. Today these metal based additives are found as: particles, ions absorbed/exchanged in different carriers, salts, hybrid structures, etc. One recent route to further extend the antimicrobial applications of these metals is by their incorporation as nanoparticles into polymer matrices. These polymer/metal nanocomposites can be prepared by several routes such as in situ synthesis of the nanoparticle within a hydrogel or direct addition of the metal nanofiller into a thermoplastic matrix. The objective of the present review is to show examples of polymer/metal composites designed to have antimicrobial activities, with a special focus on copper and silver metal nanoparticles and their mechanisms.

  9. CO responses of sensors based on cerium oxide thick films prepared from clustered spherical nanoparticles.

    Science.gov (United States)

    Izu, Noriya; Matsubara, Ichiro; Itoh, Toshio; Akamatsu, Takafumi; Shin, Woosuck

    2013-03-08

    Various types of CO sensors based on cerium oxide (ceria) have been reported recently. It has also been reported that the response speed of CO sensors fabricated from porous ceria thick films comprising nanoparticles is extremely high. However, the response value of such sensors is not suitably high. In this study, we investigated methods of improving the response values of CO sensors based on ceria and prepared gas sensors from core-shell ceria polymer hybrid nanoparticles. These hybrid nanoparticles have been reported to have a unique structure: The core consists of a cluster of ceria crystallites several nanometers in size. We compared the characteristics of the sensors based on thick films prepared from core-shell nanoparticles with those of sensors based on thick films prepared from conventionally used precipitated nanoparticles. The sensors prepared from the core-shell nanoparticles exhibited a resistance that was ten times greater than that of the sensors prepared from the precipitated nanoparticles. The response values of the gas sensors based on the core-shell nanoparticles also was higher than that of the sensors based on the precipitated nanoparticles. Finally, improvements in sensor response were also noticed after the addition of Au nanoparticles to the thick films used to fabricate the two types of sensors.

  10. Space-selective DNA Deposition Controlled by Photothermal Heating of Gold Nanoparticles

    Science.gov (United States)

    Rajewale, Sarita B.

    Mono-layers of bio-molecules exhibit poor optical absorption. However, nanoparticles of metals such as gold are efficient light absorbers. Surface plasmons generated by laser excitation of gold nanoparticles lead to an enhanced absorption cross section, ultimately producing photothermal energy. This dissertation is focused on implementing laser-induced photothermal energy for space-selective DNA deposition onto a solid surface for high density micro-gene array fabrication. The fabrication method uses visible wavelength laser-irradiation of gold nanoparticles to locally de-hybridize fluorescently labeled DNA oligonucleotides immobilized on a substrate surface. Fluorescently labeled complimentary DNAs were then added to the samples to validate space-selective DNA re-hybridization. Under optimum conditions, the addition of complimentary DNA caused a restoration of fluorescence in the laser-irradiated region thereby confirming successful DNA de-hybridization and re-hybridization. Subsequent experiments were performed to identify optimum conditions for photothermal de-hybridization of DNA. These experiments evaluated the performance of the de-hybridization process with respect to variations in gold nanoparticles size, gold nanoparticle concentration, laser repetition rate, laser exposure time, sample buffer temperature, sample buffer pH, and sample buffer ionic concentrations. Feature sizes as small as 5 micrometers could be attained. This study identified and refined a photothermal method that can be used in generating high density, micro-featured, and uniform DNA arrays that have applications in the DNA chip fabrication technology.

  11. Increasing the Collision Rate of Particle Impact Electroanalysis with Magnetically Guided Pt-Decorated Iron Oxide Nanoparticles.

    Science.gov (United States)

    Robinson, Donald A; Yoo, Jason J; Castañeda, Alma D; Gu, Brett; Dasari, Radhika; Crooks, Richard M; Stevenson, Keith J

    2015-07-28

    An integrated microfluidic/magnetophoretic methodology was developed for improving signal response time and detection limits for the chronoamperometric observation of discrete nanoparticle/electrode interactions by electrocatalytic amplification. The strategy relied on Pt-decorated iron oxide nanoparticles which exhibit both superparamagnetism and electrocatalytic activity for the oxidation of hydrazine. A wet chemical synthetic approach succeeded in the controlled growth of Pt on the surface of FeO/Fe3O4 core/shell nanocubes, resulting in highly uniform Pt-decorated iron oxide hybrid nanoparticles with good dispersibility in water. The unique mechanism of hybrid nanoparticle formation was investigated by electron microscopy and spectroscopic analysis of isolated nanoparticle intermediates and final products. Discrete hybrid nanoparticle collision events were detected in the presence of hydrazine, an electrochemical indicator probe, using a gold microband electrode integrated into a microfluidic channel. In contrast with related systems, the experimental nanoparticle/electrode collision rate correlates more closely with simple theoretical approximations, primarily due to the accuracy of the nanoparticle tracking analysis method used to quantify nanoparticle concentrations and diffusion coefficients. Further modification of the microfluidic device was made by applying a tightly focused magnetic field to the detection volume to attract the magnetic nanoprobes to the microband working electrode, thereby resulting in a 6-fold increase to the relative frequency of chronoamperometric signals corresponding to discrete nanoparticle impact events.

  12. Facile approach to prepare Pt decorated SWNT/graphene hybrid catalytic ink

    International Nuclear Information System (INIS)

    Highlights: • Pt NPs were in situ synthesized onto CNT–graphene support in aqueous solution. • The as-prepared material was used directly as a catalyst ink without further treatment. • Catalyst ink is active toward methanol oxidation. • This approach realizes both scalable and greener production of hybrid catalysts. - Abstract: Platinum nanoparticles were in situ synthesized onto hybrid support involving graphene and single walled carbon nanotube in aqueous solution. We investigate the reduction of graphene oxide, and platinum nanoparticle functionalization on hybrid support by X-ray photoelectron spectroscopy, Raman spectroscopy, X-ray diffraction, scanning electron microscopy and transmission electron microscopy. The as-prepared platinum on hybrid support was used directly as a catalyst ink without further treatment and is active toward methanol oxidation. This work realizes both scalable and greener production of highly efficient hybrid catalysts, and would be valuable for practical applications of graphene based fuel cell catalysts

  13. Facile approach to prepare Pt decorated SWNT/graphene hybrid catalytic ink

    Energy Technology Data Exchange (ETDEWEB)

    Mayavan, Sundar, E-mail: sundarmayavan@cecri.res.in [Centre for Innovation in Energy Research, CSIR–Central Electrochemical Research Institute, Karaikudi 630006, Tamil Nadu (India); Department of Nuclear and Quantum Engineering, Korea Advanced Institute of Science and Technology, Daejeon, 305-701 (Korea, Republic of); Mandalam, Aditya; Balasubramanian, M. [Centre for Innovation in Energy Research, CSIR–Central Electrochemical Research Institute, Karaikudi 630006, Tamil Nadu (India); Sim, Jun-Bo [Department of Nuclear and Quantum Engineering, Korea Advanced Institute of Science and Technology, Daejeon, 305-701 (Korea, Republic of); Choi, Sung-Min, E-mail: sungmin@kaist.ac.kr [Department of Nuclear and Quantum Engineering, Korea Advanced Institute of Science and Technology, Daejeon, 305-701 (Korea, Republic of)

    2015-07-15

    Highlights: • Pt NPs were in situ synthesized onto CNT–graphene support in aqueous solution. • The as-prepared material was used directly as a catalyst ink without further treatment. • Catalyst ink is active toward methanol oxidation. • This approach realizes both scalable and greener production of hybrid catalysts. - Abstract: Platinum nanoparticles were in situ synthesized onto hybrid support involving graphene and single walled carbon nanotube in aqueous solution. We investigate the reduction of graphene oxide, and platinum nanoparticle functionalization on hybrid support by X-ray photoelectron spectroscopy, Raman spectroscopy, X-ray diffraction, scanning electron microscopy and transmission electron microscopy. The as-prepared platinum on hybrid support was used directly as a catalyst ink without further treatment and is active toward methanol oxidation. This work realizes both scalable and greener production of highly efficient hybrid catalysts, and would be valuable for practical applications of graphene based fuel cell catalysts.

  14. Chemical surface tuning electrocatalysis of redox-active nanoparticles

    DEFF Research Database (Denmark)

    Zhu, Nan; Ulstrup, Jens; Chi, Qijin

    This work focuses on electron transfer (ET) and electrocatalysis of inorganic hybrid Prussian blue nanoparticles (PBNPs, 6 nm) immobilized on different chemical surfaces. Through surface self-assembly chemistry, we have enabled to tune chemical properties of the electrode surface. Stable immobili...

  15. Toward efficient modification of large gold nanoparticles with DNA

    NARCIS (Netherlands)

    Gill, R.; Goeken, K.L.; Subramaniam, V.

    2014-01-01

    DNA-coated gold nanoparticles are one of the most researched nano-bio hybrid systems. Traditionally their synthesis has been a long and tedious process, involving slow salt addition and long incubation steps. This stems from the fact that both DNA and gold particles are negatively charged, therefore

  16. Environment-sensitive stabilisation of silver nanoparticles in aqueous solutions

    NARCIS (Netherlands)

    Voets, I.K.; Keizer, de A.; Frederik, P.M.; Jellema, R.; Stuart, M.A.C.

    2009-01-01

    We describe the preparation and characterisation of inorganic-organic hybrid block copolymer silver nanoparticles via the preparation of spherical multi-responsive polymeric micelles of poly(N-methyl-2-vinyl pyridinium iodide)-block-poly(ethylene oxide), P2MVP(38)-b-PEO211, and poly(acrylic acid)-bl

  17. Recent advances in multifunctional silica-based hybrid nanocarriers for bioimaging and cancer therapy

    Science.gov (United States)

    Lim, Wei Qi; Phua, Soo Zeng Fiona; Xu, Hesheng Victor; Sreejith, Sivaramapanicker; Zhao, Yanli

    2016-06-01

    In recent years, there has been a considerable research focus on integrating cancer cell imaging and therapeutic functions into single nanoscale platforms for better treatment of cancer. This task could often be achieved by incorporating multiple components into a hybrid nanosystem. In this minireview, we highlight different types of silica-based hybrid nanosystems and their recent applications as integrated multifunctional platforms for cancer imaging and treatment. The discussions are divided into several sections focusing on various types of materials employed to integrate with silica, which include silica-metallic nanoparticle based hybrid nanocarriers, silica-gold nanoparticle based hybrid nanocarriers, silica-quantum dot based hybrid nanocarriers, silica-upconversion nanoparticle based hybrid nanocarriers, silica-carbon based hybrid nanocarriers, and organosilica nanocarriers. Therapeutic agents loaded in such hybrids include chemodrugs, proteins, DNA/RNA and photosensitizers. For targeted delivery into tumor sites, targeting ligands such as antibodies, peptides, aptamers, and other small molecules are grafted on the surface of the nanocarriers. At the end of the review, a brief summary and research outlook are presented. This minireview aims to provide a quick update of recent research achievements in the field.

  18. Accelerated Blood Clearance Phenomenon Reduces the Passive Targeting of PEGylated Nanoparticles in Peripheral Arterial Disease.

    Science.gov (United States)

    Im, Hyung-Jun; England, Christopher G; Feng, Liangzhu; Graves, Stephen A; Hernandez, Reinier; Nickles, Robert J; Liu, Zhuang; Lee, Dong Soo; Cho, Steve Y; Cai, Weibo

    2016-07-20

    Peripheral arterial disease (PAD) is a leading global health concern. Due to limited imaging and therapeutic options, PAD and other ischemia-related diseases may benefit from the use of long circulating nanoparticles as imaging probes and/or drug delivery vehicles. Polyethylene glycol (PEG)-conjugated nanoparticles have shown shortened circulation half-lives in vivo when injected multiple times into a single subject. This phenomenon has become known as the accelerated blood clearance (ABC) effect. The phenomenon is of concern for clinical translation of nanomaterials as it limits the passive accumulation of nanoparticles in many diseases, yet it has not been evaluated using inorganic or organic-inorganic hybrid nanoparticles. Herein, we found that the ABC phenomenon was induced by reinjection of PEGylated long circulating organic-inorganic hybrid nanoparticles, which significantly reduced the passive targeting of (64)Cu-labeled PEGylated reduced graphene oxide-iron oxide nanoparticles ((64)Cu-RGO-IONP-PEG) in a murine model of PAD. Positron emission tomography (PET) imaging was performed at 3, 10, and 17 days postsurgical induction of hindlimb ischemia. At day 3 postsurgery, the nanoparticles displayed a long circulation half-life with enhanced accumulation in the ischemic hindlimb. At days 10 and 17 postsurgery, reinjected mice displayed a short circulation half-life and lower accumulation of the nanoparticles in the ischemic hindlimb, in comparison to the naïve group. Also, reinjected mice showed significantly higher liver uptake than the naïve group, indicating that the nanoparticles experienced higher sequestration by the liver in the reinjected group. Furthermore, photoacoustic (PA) imaging and Prussian blue staining confirmed the enhanced accumulation of the nanoparticles in the liver tissue of reinjected mice. These findings validate the ABC phenomenon using long circulating organic-inorganic hybrid nanoparticles upon multiple administrations to the same

  19. Synthesis and Characterization of Re.Dispersible Silver Nanoparticles/Polyurethane Hybrid Materials%一种可再分散的纳米银/聚氨酯杂化材料的制备及表征

    Institute of Scientific and Technical Information of China (English)

    杨兆钰; 邱淑璇; 王勇利; 吕宏达; 邢喜红; 罗建斌

    2012-01-01

    Re-dispersible nano-silver particle/polyurethane composites with long stability were prepared in situ using polyurethane with d