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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.

    2016-05-01

    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.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. Electronic supplementary information (ESI) available: Additional TEM images and extinction spectra of Si-metal hybrid NPs are shown in Fig. S1

  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. 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 indefinit...

  7. 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

  8. Hybrid gold nanoparticles in molecular imaging and radiotherapy

    International Nuclear Information System (INIS)

    Metallic nanoparticles, because of their size, chemical and physical properties, are particularly attractive as therapeutic probes in treating cancer. Central to any clinical advances in nanoparticulate based therapy will be to produce hybrid nanoparticles that can be targeted to vascular, extracellular or cell surface receptors. Development of hybrid nanoparticles that specifically target cancer vasculature has received considerable attention. Most cancers have leaky vasculature and the defective vascular architecture, created due to the rapid vascularization necessary to serve fast growing cancers, in combination with poor lymphatic drainage allows increased permeation and retention effects. The leaky vasculature, because of higher porosity and permeability, serve as natural high affinity targets to metallic nanoparticles. Another attractive approach toward the application of nanotechnology to nanomedicine is the utility of nanoparticles that display inherent therapeutic properties. For example radioactive gold nanoparticles present attractive prospects in therapy of cancer. The radioactive properties of Au-198 (βmax = 0.96 MeV; t1/2 = 2.7 d) and Au-199 (βmax = 0.46 MeV; t1/2 = 3.14 d) make them ideal candidates for use in radiotherapeutic applications. In addition, they both have imageable gamma emissions for dosimetry and pharmacokinetic studies and Au-199 can be made carrier-free by indirect methods. Gold nanoparticles are of interest for treatment of disease as they can deliver agents directly into cells and cellular components with a higher concentration of radioactivity, e.g. higher dose of radioactivity, to cancerous tumour cells. This presentation will provide latest results on (i) the production of biocompatible hybrid gold nanoparticles; (ii) production, characterization and biodistribution of Au-198 nanoparticles and (iii) details on the utility of gold nanoparticles in molecular imaging using X ray contrast (CT) techniques. (author)

  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. 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

  11. 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...

  12. 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.

  13. Amphiphilic polymer-coated hybrid nanoparticles as CT/MRI dual contrast agents

    Science.gov (United States)

    Kim, Dongkyu; Yu, Mi Kyung; Lee, Tae Sup; Park, Jae Jun; Jeong, Yong Yeon; Jon, Sangyong

    2011-04-01

    We describe hybrid nanoparticles, composed of iron oxide and gold nanoparticles, as potential dual contrast agents for both computed tomography (CT) and magnetic resonance imaging (MRI). The hybrid nanoparticles are synthesized by thermal decomposition of mixtures of Fe-oleate and Au-oleylamine complexes. Using a nano-emulsion method, the nanoparticles are coated with amphiphilic poly(DMA-r-mPEGMA-r-MA) to impart water-dispersity and antibiofouling properties. An in vitro phantom study shows that the hybrid nanoparticles have high CT attenuation, because of the constituent gold nanoparticles, and afford a good MR signal, attributable to the contained iron oxide nanoparticles. Intravenous injection of the hybrid nanoparticles into hepatoma-bearing mice results in high contrast between the hepatoma and normal hepatic parenchyma in both CT and MRI. These results suggest that the hybrid nanoparticles may be useful as CT/MRI dual contrast agents for in vivo hepatoma imaging.

  14. Amphiphilic polymer-coated hybrid nanoparticles as CT/MRI dual contrast agents

    International Nuclear Information System (INIS)

    We describe hybrid nanoparticles, composed of iron oxide and gold nanoparticles, as potential dual contrast agents for both computed tomography (CT) and magnetic resonance imaging (MRI). The hybrid nanoparticles are synthesized by thermal decomposition of mixtures of Fe-oleate and Au-oleylamine complexes. Using a nano-emulsion method, the nanoparticles are coated with amphiphilic poly(DMA-r-mPEGMA-r-MA) to impart water-dispersity and antibiofouling properties. An in vitro phantom study shows that the hybrid nanoparticles have high CT attenuation, because of the constituent gold nanoparticles, and afford a good MR signal, attributable to the contained iron oxide nanoparticles. Intravenous injection of the hybrid nanoparticles into hepatoma-bearing mice results in high contrast between the hepatoma and normal hepatic parenchyma in both CT and MRI. These results suggest that the hybrid nanoparticles may be useful as CT/MRI dual contrast agents for in vivo hepatoma imaging.

  15. 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.

  16. Hybrid Nanomaterials: One Dimensional Nanoparticle Assemblies

    Science.gov (United States)

    Sharma, Nikhil; Pochan, Darrin

    2007-03-01

    One-dimensional nanoparticle assemblies have potential applications in sensing, as plasmon and energy waveguides and in the conduction of novel signals such as phonons and spin states. Herein we present two strategies for the fabrication of such assemblies. Micro and meso-scale particle assemblies have been produced via a coaxial electrospinning process that results in assemblies of particles (silica and silver) encapsulated within a polymer nanofiber (polyethylene oxide). The method has been demonstrated successfully in the creation of 1D assemblies of differently sized silica particles. The effect of change in solution concentrations and relative flow rates in internal and external channels of the coaxial electrospinning apparatus on the structure of these assemblies has been investigated. Nano-scale assemblies of gold particles have been prepared by templating gold nanoparticles on a 20 amino acid peptide that displays laminated morphology. These assemblies are formed as laterally spaced one-dimensional nanoparticle assemblies.

  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. 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.

  19. 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.

  20. 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.

  1. Synthesis of polymeric and hybrid nanoparticles for electroplating applications

    International Nuclear Information System (INIS)

    Monodisperse polymeric particles with diameters in the range of 60-1400 nm were prepared by (emulsifier-free) emulsion polymerization and incorporated into electrolytic zinc coatings aiming to improve the corrosion resistance of electrogalvanized steel. Various types of polymeric nanoparticles were thus synthesized in order to assess the effect of the emulsifier, initiator and comonomer type on the particle morphology, stability and codeposition behavior. The polymerization experiments were carried out in laboratory-scale glass reactors and the most promising recipes were successfully scaled-up in a fully automated pilot-scale reactor. Replicates of some representative experiments, which were run both in lab and pilot-scale reactors, indicated excellent reproducibility of the polymerization process. Uniform, polymer-containing zinc coatings were produced by electrolytic codeposition of the nanoparticles from an acid zinc plating bath using a rotating disk electrode (RDE). Hybrid polystyrene/silica nanoparticles with increased silica content were also prepared via emulsifier-free emulsion polymerization, in the presence of an ultrafine aqueous silica sol, to be used in electrocoating applications. The effect of key process parameters, such as initial monomers molar ratio and pH on the size, morphology and silica content of the produced hybrid nanoparticles was investigated

  2. Vermiculite decorated with copper nanoparticles: Novel antibacterial hybrid material

    Science.gov (United States)

    Drelich, Jaroslaw; Li, Bowen; Bowen, Patrick; Hwang, Jiann-Yang; Mills, Owen; Hoffman, Daniel

    2011-09-01

    Vermiculite decorated with copper nanoparticles is a new antibacterial material that was prepared in this study through ion-exchange process and hydrogen reduction. The replacement of magnesium ions in interlayer structure was carried out using concentrated copper sulfate solutions at elevated temperature. Copper ions were reduced to elemental copper at 400-600 °C using hydrogen as the reducing agent. During the reduction process copper diffused primarily to vermiculite surface regions and formed copper nanoparticles with a broad range of sizes, from ˜1 to 400 nm. Strong adhesion of copper nanoparticles to the vermiculite carrier makes this hybrid very stable and durable. The new vermiculite-metallic copper hybrid material shows strong antibacterial activity against Staphylococcus aureus at 37 °C. Vermiculite is an inexpensive mineral that is very stable under a wide range of industrial and environmental conditions, and extensively used as filler in fireproof materials, plastics, paints and lightweight concrete, so the addition of copper as an antibacterial agent opens new avenues for the application of vermiculite in consumer products and other areas.

  3. Metal sulfide nanoparticle/polymer hybrid solar cells

    International Nuclear Information System (INIS)

    Full text: The decomposition of metal xanthates directly in a matrix of a conjugated polymer have been recently been introduced for copper indium sulphide polymer solar cells reaching efficiencies up to 3 %. Using this process the nanoparticles are naked without a ligand shell. In this contribution we show the versatility of this process to other metal sulphides-polymer systems. Aspects of materials synthesis and devices physics will be discussed. Different electrodes (Ag, Ag/Al, Al) have a strong influence on efficiency as well as devices stability. In addition, first results on tandem hybrid solar cells using the xanthate approach will be presented. (author)

  4. 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.

  5. Synthesis and Characterization of Lipid-Polymer Hybrid Nanoparticles with pH-Triggered PEG Shedding

    OpenAIRE

    Clawson, Corbin; Ton, Linh; Aryal, Santosh; Fu, Victoria; Esener, Sadik; Zhang, Liangfang

    2011-01-01

    Novel lipid-polymer hybrid nanoparticles are designed with a poly(ethylene glycol) coating that is shed in response to a low pH trigger. This allows the nanoparticles to be stable during systemic circulation and at neutral pH, but destabilize and fuse with lipid membranes in acidic environments. The hybrid nanoparticles consist of a poly(lactic-co-glycolic acid) core with a lipid and lipid-PEG monolayer shell. To make the hybrid nanoparticles pH sensitive, a lipid-(succinate)-mPEG conjugate i...

  6. 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.

  7. 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

  8. 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.

  9. 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.

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

    International Nuclear Information System (INIS)

    In this study, Poly (3-hexylthiophene) (P3HT): [6,6]-phenyl C61-butyric (PCBM): titania (TiO2): 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 H2PtCl6·6H2O 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/cm2 and 2.17% to 10.10 mA/cm2 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:TiO2. - Highlights: • A P3HT:PCBM:TiO2 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

  11. 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.

  12. Synthesis and Properties of Hybrid Colloidal Au-CdSe Nanoparticles

    OpenAIRE

    O.A. Balitskii

    2012-01-01

    The communication is devoted to the synthesis procedure and properties of hybrid nanoparticles of colloidal gold with cadmium selenide. Optical and morphological characteristics of the above mentioned particles, as well as the formation mechanism, are discussed.

  13. Synthesis and Properties of Hybrid Colloidal Au-CdSe Nanoparticles

    Directory of Open Access Journals (Sweden)

    O.A. Balitskii

    2012-05-01

    Full Text Available The communication is devoted to the synthesis procedure and properties of hybrid nanoparticles of colloidal gold with cadmium selenide. Optical and morphological characteristics of the above mentioned particles, as well as the formation mechanism, are discussed.

  14. Strontium eluting graphene hybrid nanoparticles augment osteogenesis in a 3D tissue scaffold

    Science.gov (United States)

    Kumar, Sachin; Chatterjee, Kaushik

    2015-01-01

    The objective of this work was to prepare hybrid nanoparticles of graphene sheets decorated with strontium metallic nanoparticles and demonstrate their advantages in bone tissue engineering. Strontium-decorated reduced graphene oxide (RGO_Sr) hybrid nanoparticles were synthesized by the facile reduction of graphene oxide and strontium nitrate. X-ray diffraction, transmission electron microscopy, and atomic force microscopy revealed that the hybrid particles were composed of RGO sheets decorated with 200-300 nm metallic strontium particles. Thermal gravimetric analysis further confirmed the composition of the hybrid particles as 22 wt% of strontium. Macroporous tissue scaffolds were prepared by incorporating RGO_Sr particles in poly(ε-caprolactone) (PCL). The PCL/RGO_Sr scaffolds were found to elute strontium ions in aqueous medium. Osteoblast proliferation and differentiation was significantly higher in the PCL scaffolds containing the RGO_Sr particles in contrast to neat PCL and PCL/RGO scaffolds. The increased biological activity can be attributed to the release of strontium ions from the hybrid nanoparticles. This study demonstrates that composites prepared using hybrid nanoparticles that elute strontium ions can be used to prepare multifunctional scaffolds with good mechanical and osteoinductive properties. These findings have important implications for designing the next generation of biomaterials for use in tissue regeneration.The objective of this work was to prepare hybrid nanoparticles of graphene sheets decorated with strontium metallic nanoparticles and demonstrate their advantages in bone tissue engineering. Strontium-decorated reduced graphene oxide (RGO_Sr) hybrid nanoparticles were synthesized by the facile reduction of graphene oxide and strontium nitrate. X-ray diffraction, transmission electron microscopy, and atomic force microscopy revealed that the hybrid particles were composed of RGO sheets decorated with 200-300 nm metallic strontium

  15. 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 ...

  16. Electrophoretically prepared hybrid materials for biopolymer hydrogel and layered ceramic nanoparticles

    OpenAIRE

    Gwak, Gyeong-Hyeon; Choi, Ae-Jin; Bae, Yeoung-Seuk; Choi, Hyun-Jin; Oh, Jae-Min

    2016-01-01

    Background In order to obtain biomaterials with controllable physicochemical properties, hybrid biomaterials composed of biocompatible biopolymers and ceramic nanoparticles have attracted interests. In this study, we prepared biopolymer/ceramic hybrids consisting of various natural biopolymers and layered double hydroxide (LDH) ceramic nanoparticles via an electrophoretic method. We studied the structures and controlled-release properties of these materials. Results and discussion X-ray diffr...

  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. 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

  19. Novel hybrid nanostructured materials of magnetite nanoparticles and pectin

    International Nuclear Information System (INIS)

    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. - 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 materials has

  20. 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

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

    Science.gov (United States)

    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.

  2. Carbon Dioxide-Mediated Generation of Hybrid Nanoparticles for Improved Bioavailability of Protein Kinase Inhibitors

    OpenAIRE

    Jesson, Gérald; Brisander, Magnus; Andersson, Per; Demirbüker, Mustafa; Derand, Helene; Lennernäs, Hans; Malmsten, Martin

    2013-01-01

    ABSTRACT Purpose A versatile methodology is demonstrated for improving dissolution kinetics, gastrointestinal (GI) absorption, and bioavailability of protein kinase inhibitors (PKIs). Methods The approach is based on nanoparticle precipitation by sub- or supercritical CO2 together with a matrix-forming polymer, incorporating surfactants either during or after nanoparticle formation. Notably, striking synergistic effects between hybrid PKI/polymer nanoparticles and surfactant added after parti...

  3. 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.

  4. 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

  5. Hybrid composite thin films composed of tin oxide nanoparticles and cellulose

    International Nuclear Information System (INIS)

    This paper reports the preparation and characterization of hybrid thin films consisting of tin oxide (SnO2) nanoparticles and cellulose. SnO2 nanoparticle loaded cellulose hybrid thin films were fabricated by a solution blending technique, using sodium dodecyl sulfate as a dispersion agent. Scanning and transmission electron microscopy studies revealed uniform dispersion of the SnO2 nanoparticles in the cellulose matrix. Reduction in the crystalline melting transition temperature and tensile properties of cellulose was observed due to the SnO2 nanoparticle loading. Potential application of these hybrid thin films as low cost, flexible and biodegradable humidity sensors is examined in terms of the change in electrical resistivity of the material exposed to a wide range of humidity as well as its response–recovery behavior. (paper)

  6. Color-tunable magnetic and luminescent hybrid nanoparticles: Synthesis, optical and magnetic properties

    Energy Technology Data Exchange (ETDEWEB)

    Lou Lei [Key Laboratory of Polar Materials and Devices (Ministry of Education of China), Department of Electronic Engineering, East China Normal University, Shanghai 200241 (China); Yu Ke, E-mail: yk5188@263.net [Key Laboratory of Polar Materials and Devices (Ministry of Education of China), Department of Electronic Engineering, East China Normal University, Shanghai 200241 (China); Wang Yiting [Institutes for Advanced Interdisciplinary Research, East China Normal University, Shanghai 200062 (China); Zhu Ziqiang [Key Laboratory of Polar Materials and Devices (Ministry of Education of China), Department of Electronic Engineering, East China Normal University, Shanghai 200241 (China)

    2012-02-01

    A facile method for synthesizing color-tunable magnetic and luminescent hybrid bifunctional nanoparticles is presented. A series of CdSe/ZnS core-shell quantum dots (QDs) with different sizes were successfully fabricated and self-assembled to Fe{sub 3}O{sub 4} magnetic nanoparticles (MNP), which were subsequently coated with a polyethyleneimine (PEI) layer to prevent large aggregates. The hydrophobic QDs capped with trioctylphosphine oxide (TOPO) formed a coating surrounding MNP, and were transferred into hydrophilic phase by PEI with high efficiency. The samples were characterized by TEM, FT-IR, XRD, EDS, UV-vis spectrophotometer, fluorescent spectrophotometer and PPMS. Results show that the original properties of the nanoparticles were well-preserved in the hybrid structure. All MNP-QDs hybrid nanoparticles showed paramagnetic behavior and the nanocomposites were still highly luminescent with no shift in the PL peak position.

  7. Surface-enhanced Raman effect in hybrid metal-semiconductor nanoparticle assemblies

    Energy Technology Data Exchange (ETDEWEB)

    Lughi, Vanni, E-mail: vanni.lughi@di3.units.it; Bonifacio, Alois [University of Trieste, Department of Engineering and Architecture (Italy); Barbone, Matteo [University of Cambridge, Electrical Engineering Division, Engineering Department (United Kingdom); Marsich, Lucia; Sergo, Valter [University of Trieste, Department of Engineering and Architecture (Italy)

    2013-05-15

    Hybrid metal-semiconductor nanoparticles consisting of silver nanoparticle cores (AgNPs) coated with a layer of CdSe quantum dots (QDs) have been studied by Raman spectroscopy. The hybrid nanoparticles were prepared via electrostatic interaction by mixing aqueous suspensions of QDs and AgNPs, where opposite charges on the AgNPs and QDs surfaces were induced by opportunely selected capping agents. Assemblies of such hybrid nanoparticles show an increased intensity of the Raman spectrum of up to 500 times, when compared to that of the sole QDs. This enhancement is attributed to the SERS effect (Surface-enhanced Raman scattering). Such enhancement of the Raman modes suggests several opportunities for further research, both in imaging and sensing applications.

  8. Extraordinarily high conductivity of flexible adhesive films by hybrids of silver nanoparticle-nanowires.

    Science.gov (United States)

    Ajmal, C Muhammed; Menamparambath, Mini Mol; Choi, Hyouk Ryeol; Baik, Seunghyun

    2016-06-01

    Highly conductive flexible adhesive (CFA) film was developed using micro-sized silver flakes (primary fillers), hybrids of silver nanoparticle-nanowires (secondary fillers) and nitrile butadiene rubber. The hybrids of silver nanoparticle-nanowires were synthesized by decorating silver nanowires with silver nanoparticle clusters using bifunctional cysteamine as a linker. The dispersion in ethanol was excellent for several months. Silver nanowires constructed electrical networks between the micro-scale silver flakes. The low-temperature surface sintering of silver nanoparticles enabled effective joining of silver nanowires to silver flakes. The hybrids of silver nanoparticle-nanowires provided a greater maximum conductivity (54 390 S cm(-1)) than pure silver nanowires, pure multiwalled carbon nanotubes, and multiwalled carbon nanotubes decorated with silver nanoparticles in nitrile butadiene rubber matrix. The resistance change was smallest upon bending when the hybrids of silver nanoparticle-nanowires were employed. The adhesion of the film on polyethylene terephthalate substrate was excellent. Light emitting diodes were successfully wired to the CFA circuit patterned by the screen printing method for application demonstration. PMID:27109551

  9. 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.

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

    International Nuclear Information System (INIS)

    Graphical abstract: - Highlights: • Photothermal processing of TiO2 and hybrid Au/TiO2 nanoparticles using continuous-wave lasers is demonstrated. • Processing of TiO2 nanoparticles at 355 nm results in a transition from anatase to rutile. • Decoration of TiO2 nanoparticles with Au nanoparticles results in an increased absorbance in the visible range. • Hybrid Au/TiO2 nanoparticles can be processed at 355 nm and 532 nm in a large laser parameter window. • Processing of hybrid Au/TiO2 nanoparticles at 532 nm can be carried out at low laser powers and short laser pulse lengths. - Abstract: 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

  11. 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.

  12. Tunnelling conductive hybrid films of gold nanoparticles and cellulose and their applications as electrochemical electrodes.

    Science.gov (United States)

    Liu, Zhiming; Wang, Xuefeng; Li, Mei; Wu, Wenjian

    2015-11-20

    Conductive hybrid films of metal nanoparticles and polymers have practical applications in the fields of sensing, microelectronics and catalysis, etc. Herein, we present the electrochemical availability of tunnelling conductive hybrid films of gold nanoparticles (GNPs) and cellulose.The hybrid films were provided with stable tunnelling conductive properties with 12 nm GNPs of 12.7% (in weight). For the first time, the conductive hybrid films were used as substrates of electrochemical electrodes to load calmodulin (CaM) proteins for sensing of calcium cations.The electrodes of hybrid films with 20 nm GNPs of 46.7% (in weight) exhibited stable electrochemical properties, and showed significant responses to calcium cations with concentrations as low as 10(−9) M after being loaded with CaM proteins. PMID:26511782

  13. 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.

  14. 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.

  15. 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.

  16. 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.

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

    International Nuclear Information System (INIS)

    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−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

  18. 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.

  19. A Sustainable Approach to Fabricating Ag Nanoparticles/PVA Hybrid Nanofiber and Its Catalytic Activity

    Directory of Open Access Journals (Sweden)

    Yongde Meng

    2015-06-01

    Full Text Available Ag nanoparticles were synthesized by using Ficus altissima Blume leaf extract as a reducing agent at room temperature. The resulting Ag nanoparticles/PVA mixture was employed to create Ag nanoparticles/PVA (polyvinyl alcohol hybrid nanofibers via an electrospinning technique. The obtained nanofibers were confirmed by means of UV-Vis spectroscopy, The X-ray diffraction (XRD, Fourier transform infrared (FTIR spectroscopy, scanning electron microscopy (SEM, transmission electron microscopy (TEM, and then tested to catalyze KBH4 reduction of methylene blue (MB. The catalytic results demonstrate that the MB can be reduced completely within 15 min. In addition, the Ag nanoparticles/PVA hybrid nanofibers show reusability for three cycles with no obvious losses in degradation ratio of the MB.

  20. Synthesis and Catalytic Features of Hybrid Metal Nanoparticles Supported on Cellulose Nanofibers

    OpenAIRE

    Hirotaka Koga; Akihiro Azetsu; Akira Isogai; Takuya Kitaoka

    2011-01-01

    The structural and functional design of metal nanoparticles has recently allowed remarkable progress in the development of high-performance catalysts. Gold nanoparticles (AuNPs) are among the most innovative catalysts, despite bulk Au metal being regarded as stable and inactive. The hybridization of metal NPs has attracted major interest in the field of advanced nanocatalysts, due to electro-mediated ligand effects. In practical terms, metal NPs need to be supported on a suitable matrix to av...

  1. 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...

  2. 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.

  3. 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......-energy-loss range as a contrast enhancement mechanism for imaging the organic shells of such particles. We also study electron-beam-induced crystallization and amorphization of the shells and the formation of graphitic-like layers that contain both C and N. The resistance of the samples to irradiation by high...

  4. 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...

  5. 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

  6. Silica nanoparticles as inorganic scaffolds for the preparation of hybrid materials for the optical detection of anions

    OpenAIRE

    CALERO RODRIGUEZ, MARÍA PILAR

    2016-01-01

    [EN] The PhD Thesis entitled "Silica nanoparticles as inorganic scaffolds for the preparation of hybrid materials for the optical detection of anions" deals with the combination of supramolecular and material chemistry concepts to prepare hybrid sensing materials with the ability to detect selected ions through color and emission changes. The first hybrid material prepared is based in the use of silica nanoparticles as inorganic scaffold functionalized with spirobenzopyrans (signaling uni...

  7. 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

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

    International Nuclear Information System (INIS)

    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 AgNO3 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: ► Antibacterial activity of films (zirconia–polyether glycol) modified with silver nanoparticles. ► Biofilm formation is prevented. ► High sensibility against gram positive bacteria.

  9. 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

  10. Carbon nanotube anions for the preparation of gold nanoparticle-nanocarbon hybrids.

    Science.gov (United States)

    Bayazit, Mustafa K; Hodge, Stephen A; Clancy, Adam J; Menzel, Robert; Chen, Shu; Shaffer, Milo S P

    2016-01-31

    Gold nanoparticles (AuNPs) can be evenly deposited on single-walled carbon nanotubes (SWCNTs) via the reduction of the highly stable complex, chloro(triphenylphosphine) gold(I), with SWCNT anions ('nanotubides'). This methodology highlights the unusual chemistry of nanotubides and provides a blueprint for the generation of many other hybrid nanomaterials. PMID:26679693

  11. 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.

  12. Hyperbranched polymer mediated fabrication of water soluble carbon nanotube-metal nanoparticle hybrids

    Science.gov (United States)

    Li, Haiqing; Cooper-White, Justin J.

    2013-03-01

    1-Pyrenemethanol initiated hyperbranched polyglycerol (PiHP) has been synthesized and utilized to non-covalently functionalize pristine multi-walled carbon nanotubes (CNTs) through π-π stacking interactions. Mediated with the PiHP coating, a variety of metal nanoparticles (Au, Ag, Pd and Pt) were in situ generated and randomly tethered on the CNT sidewalls, producing various water-soluble CNT/PiHP/metal hybrids. Particularly, the resulting CNT/PiHP/Pt hybrids possess improved metal coverage in comparison to the reported CNT/Pt nanohybrids obtained by the use of conventional non-covalent CNT surface-modifiers. Depending on the using concentration of Pt2+ precursor, Pt coverage in CNT/PiHP/Pt hybrids can be effectively controlled. In the meanwhile, Pt component on the CNT sidewalls can be either well isolated nanoparticles or loose ``nanoclusters''. To test the promising catalytic application of these obtained CNT/PiHP/Pt hybrids, a systematic investigation on their catalytic performance towards the reduction of 4-nitrophenol to produce 4-aminophenol was performed. Surprisingly, these hybrids exhibited significantly enhanced catalytic activity compared with the conventionally utilized Au and Ag nanoparticles. Moreover, they can be easily recovered and reused without significant loss in catalytic activity after running 6 circles.

  13. Multifunctional Hybrid Fe2O3-Au Nanoparticles for Efficient Plasmonic Heating.

    Science.gov (United States)

    Murph, Simona E Hunyadi; Larsen, George K; Lascola, Robert J

    2016-01-01

    One of the most widely used methods for manufacturing colloidal gold nanospherical particles involves the reduction of chloroauric acid (HAuCl4) to neutral gold Au(0) by reducing agents, such as sodium citrate or sodium borohydride. The extension of this method to decorate iron oxide or similar nanoparticles with gold nanoparticles to create multifunctional hybrid Fe2O3-Au nanoparticles is straightforward. This approach yields fairly good control over Au nanoparticle dimensions and loading onto Fe2O3. Additionally, the Au metal size, shape, and loading can easily be tuned by changing experimental parameters (e.g., reactant concentrations, reducing agents, surfactants, etc.). An advantage of this procedure is that the reaction can be done in air or water, and, in principle, is amenable to scaling up. The use of such optically tunable Fe2O3-Au nanoparticles for hyperthermia studies is an attractive option as it capitalizes on plasmonic heating of gold nanoparticles tuned to absorb light strongly in the VIS-NIR region. In addition to its plasmonic effects, nanoscale Au provides a unique surface for interesting chemistries and catalysis. The Fe2O3 material provides additional functionality due to its magnetic property. For example, an external magnetic field could be used to collect and recycle the hybrid Fe2O3-Au nanoparticles after a catalytic experiment, or alternatively, the magnetic Fe2O3 can be used for hyperthermia studies through magnetic heat induction. The photothermal experiment described in this report measures bulk temperature change and nanoparticle solution mass loss as functions of time using infrared thermocouples and a balance, respectively. The ease of sample preparation and the use of readily available equipment are distinct advantages of this technique. A caveat is that these photothermal measurements assess the bulk solution temperature and not the surface of the nanoparticle where the heat is transduced and the temperature is likely to be higher

  14. 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.

  15. 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.

  16. 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

  17. 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.

  18. Increased optical contrast in imaging of epidermal growth factor receptor using magnetically actuated hybrid gold/iron oxide nanoparticles

    Science.gov (United States)

    Aaron, Jesse S.; Oh, Junghwan; Larson, Timothy A.; Kumar, Sonia; Milner, Thomas E.; Sokolov, Konstantin V.

    2006-12-01

    We describe a new approach for optical imaging that combines the advantages of molecularly targeted plasmonic nanoparticles and magnetic actuation. This combination is achieved through hybrid nanoparticles with an iron oxide core surrounded by a gold layer. The nanoparticles are targeted in-vitro to epidermal growth factor receptor, a common cancer biomarker. The gold portion resonantly scatters visible light giving a strong optical signal and the superparamagnetic core provides a means to externally modulate the optical signal. The combination of bright plasmon resonance scattering and magnetic actuation produces a dramatic increase in contrast in optical imaging of cells labeled with hybrid gold/iron oxide nanoparticles.

  19. 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 ...

  20. 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.

  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. Synthesis, characterization, and controllable drug release of pH-sensitive hybrid magnetic nanoparticles

    Energy Technology Data Exchange (ETDEWEB)

    Zhou Lilin [Key Laboratory of Organic Optoelectronics and Molecular Engineering of the Ministry of Education, Department of Chemistry, Tsinghua University, Beijing 100084 (China); Yuan Jinying [Key Laboratory of Organic Optoelectronics and Molecular Engineering of the Ministry of Education, Department of Chemistry, Tsinghua University, Beijing 100084 (China)], E-mail: yuanjy@mail.tsinghua.edu.cn; Yuan Weizhong; Sui Xiaofeng [Key Laboratory of Organic Optoelectronics and Molecular Engineering of the Ministry of Education, Department of Chemistry, Tsinghua University, Beijing 100084 (China); Wu Sizhu [Key Laboratory of Science and Technology of Controlled Chemical Reactions, Beijing University of Chemical Technology, Beijing 100029 (China); Li Zhaolong [Key Laboratory of Organic Optoelectronics and Molecular Engineering of the Ministry of Education, Department of Chemistry, Tsinghua University, Beijing 100084 (China); Shen Dezhong [Department of Chemistry, Tsinghua University, Beijing 100084 (China)

    2009-09-15

    The synthesis of magnetite nanoparticles coated with pH-sensitive poly((2-dimethylamino) ethyl methacrylate) (PDMAEMA) via atom transfer radical polymerization (ATRP) for use as novel potential carriers for targeted drug delivery and controllable release is reported. The organic/inorganic hybrid nanoparticles were obtained with a narrow molecular weight distribution. The pH-sensitivity of the nanoparticles was investigated by the measurement of the pH dependence of hydrodynamic radius and the superparamagnetism was illustrated by vibrating sample magnetometer (VSM). The behavior of model drug phenolphthalein released from the nanoparticles indicated that the rate of drug release could be effectively controlled by altering the pH values of the environment.

  3. Antibacterial continuous nanofibrous hybrid yarn through in situ synthesis of silver nanoparticles: Preparation and characterization

    International Nuclear Information System (INIS)

    Nanofibrous hybrid yarns of polyvinyl alcohol (PVA) and poly-L-lactide acid (PLLA) with the antibacterial activity were prepared that contains 0, 5, 10, 20, and 30 wt.% of silver nanoparticles according to the PVA polymer content. This was performed by electrospinning using distilled water and 2, 2, 2-trifluoroethanol as a solvent for PVA and PLLA respectively, and sodium borohydride was used as a reducing agent. The scanning electron microscope observation confirmed the formation of AgNPs into the PVA nanofiber structure, and they were uniform, bead free, cylindrical and smooth. The diameter of hybrid yarns and their nanofiber component was decreased as the silver nitrate concentration in electrospinning solutions was increased. The differential scanning calorimetry results indicated that the silver nanoparticles can form interactions with polymer chains and decrease the melting enthalpy. The mechanical analysis showed a lower stress and strain at break of the AgNP-loaded nanofibrous hybrid yarns than the unloaded hybrid yarn. However, there wasn't a statistically significant difference between the strain at break of electrospun nanofibrous hybrid yarns. Moreover, the bactericidal efficiency of all loaded samples was over 99.99%. - Highlights: • Nanofibrous hybrid yarns of PVA/PLLA with antibacterial activity were prepared. • The diameter of nanofibers was decreased as the AgNP concentration was increased. • AgNPs make interactions with amorphous phase of polymer and increase the Tg. • All loaded samples presented a good bactericidal and bacteriostatic efficiency

  4. 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.

  5. 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.

  6. Preparation of magnetic fluorochromate hybrid nanomaterials with triphenylphosphine surface modified iron oxide nanoparticles and their characterization

    International Nuclear Information System (INIS)

    In this study, a new magnetic hybrid nanomaterial Fe3O4@SiO2@PPh3@[CrO3F]− is instituted. Firstly, magnetic Fe3O4 nanoparticles have been synthesized by hydrothermal method. Next, the produced magnetic nanoparticles were covered with a silica shell via modified Stöber method. Then, the core–shell magnetic nanoparticles system Fe3O4@SiO2 functionalization was combined by utilizing (3-chloropropyl)trimethoxysilane and triphenylphosphine, to give the cationic part for immobilization of the anionic part of the Cr(VI) catalysts including [CrO3F]−. The structure of the catalyst after immobilization was investigated by using elemental analysis, X-ray fluorescence (XRF), X-ray diffraction (XRD), Fourier transform infrared (FT-IR), and solid state UV–vis. The particle size and morphology were identified by scanning electron microscope (SEM) and XRD. Magnetization properties of nanoparticles were confirmed by vibrating sample magnetometer (VSM). - Highlights: • Fe3O4 magnetic nanoparticles were synthesized with hydrothermal method. • Fe3O4@SiO2 were prepared through a modified Stober method. • Fe3O4@SiO2 was functionalized with triphenylphosphonium reagent. • Target hybrid nanomaterial was synthesized by immobilization of fluorochromate anion

  7. Antibacterial activity of hybrid chitosan-cupric oxide nanoparticles on cotton fabric.

    Science.gov (United States)

    Dhineshbabu, Nattanmi Raman; Rajendran, Venkatachalam

    2016-02-01

    In this study, cupric oxide (CuO) nanoparticles were prepared using sonochemical method. The prepared nanoparticles were studied using X-ray diffraction (XRD) pattern, Fourier transform infrared (FTIR) spectroscopy, scanning electron microscopy (SEM), and transmission electron microscopy (TEM) methods. The colloidal chitosan (CS) solution was prepared using ultrasound irradiation method and simultaneously mixed with CuO nanoparticles. The coatings of colloidal solution with and without CuO nanoparticles were studied through TEM images. The cotton fabrics were separately soaked in the prepared nanoparticle-containing (hybrid) solutions by sonication method followed by pad-dry-cure method. The structural, functional, and morphological analyses of the coated and uncoated fabrics were performed using XRD, FTIR-attenuated total reflectance, and SEM analyses, respectively. The hybrid-coated cotton fabrics showed better antibacterial activity against Staphylococcus aureus and Escherichia coli. The bioactivity performance of the coated fabrics was in the order of CuO-coated fabric > CS-coated fabric. PMID:26766868

  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 chro-matography (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 chromatography(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. 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.

  14. 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.

  15. 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...

  16. Hybrid silica coated magnetic nanoparticles decorated with gold

    Czech Academy of Sciences Publication Activity Database

    Koktan, Jakub; Kaman, Ondřej; Veverka, Miroslav; Veverka, Pavel; Herynek, V.; Řezanka, P.

    Dresden : Technische Universität, 2014. s. 98-98. [International Conference on the Scientific and Clinical Applications of Magnetic Carriers /10./. 10.06.2014-14.06.2014, Dresden] R&D Projects: GA MPO FR-TI3/521; GA ČR(CZ) GAP108/11/0807 Institutional support: RVO:68378271 Keywords : magnetic nanoparticles * cobalt-zinc ferrite * silica encapsulation * manganite perovskites * gold decoration Subject RIV: BM - Solid Matter Physics ; Magnetism

  17. 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

  18. Synthetic Strategies in the Preparation of Polymer/Inorganic Hybrid Nanoparticles

    Directory of Open Access Journals (Sweden)

    Matthew A. Hood

    2014-05-01

    Full Text Available This article reviews the recent advances and challenges in the preparation of polymer/inorganic hybrid nanoparticles. We mainly focus on synthetic strategies, basing our classification on whether the inorganic and the polymer components have been formed in situ or ex situ, of the hybrid material. Accordingly, four types of strategies are identified and described, referring to recent examples: (i ex situ formation of the components and subsequent attachment or integration, either by covalent or noncovalent bonding; (ii in situ polymerization in the presence of ex situ formed inorganic nanoparticles; (iii in situ precipitation of the inorganic components on or in polymer structures; and (iv strategies in which both polymer and inorganic component are simultaneously formed in situ.

  19. 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

    2016-07-15

    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. PMID:27255659

  20. 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 ...

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

    OpenAIRE

    Pham, Tuan Anh; Schreiber, Andreas; Sturm, 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 modificati...

  3. 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.

  4. 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...

  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. 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

  8. Biotemplated preparation of CdS nanoparticles/bacterial cellulose hybrid nanofibers for photocatalysis application

    International Nuclear Information System (INIS)

    In this work, we describe a novel facile and effective strategy to prepare micrometer-long hybrid nanofibers by deposition of CdS nanoparticles onto the substrate of hydrated bacterial cellulose nanofibers (BCF). Hexagonal phase CdS nanocrystals were achieved via a simple hydrothermal reaction between CdCl2 and thiourea at relatively low temperature. The prepared pristine BCF and the CdS/BCF hybrid nanofibers were characterized by transmission electron microscopy (TEM), X-ray diffraction (XRD), thermogravimetric analysis (TGA), UV-vis absorption spectroscopy (UV-vis), and X-ray photoelectron spectroscopy (XPS). The results reveal that the CdS nanoparticles were homogeneously deposited on the BCF surface and stabilized via coordination effect. The CdS/BCF hybrid nanofibers demonstrated high-efficiency photocatalysis with 82% methyl orange (MO) degradation after 90 min irradiation and good recyclability. The results indicate that the CdS/BCF hybrid nanofibers are promising candidate as robust visible light responsive photocatalysts.

  9. Biotemplated preparation of CdS nanoparticles/bacterial cellulose hybrid nanofibers for photocatalysis application

    Energy Technology Data Exchange (ETDEWEB)

    Yang, Jiazhi; Yu, Junwei [Key Laboratory of Soft Chemistry and Functional Materials (Ministry of Education), Nanjing University of Science and Technology, Nanjing 210094 (China); Fan, Jun [School of Environment, Nanjing University, Nanjing 210093 (China); Sun, Dongping, E-mail: dongpingsun@163.com [Key Laboratory of Soft Chemistry and Functional Materials (Ministry of Education), Nanjing University of Science and Technology, Nanjing 210094 (China); Tang, Weihua, E-mail: whtang@mail.njust.edu.cn [Key Laboratory of Soft Chemistry and Functional Materials (Ministry of Education), Nanjing University of Science and Technology, Nanjing 210094 (China); Yang, Xuejie [Key Laboratory of Soft Chemistry and Functional Materials (Ministry of Education), Nanjing University of Science and Technology, Nanjing 210094 (China)

    2011-05-15

    In this work, we describe a novel facile and effective strategy to prepare micrometer-long hybrid nanofibers by deposition of CdS nanoparticles onto the substrate of hydrated bacterial cellulose nanofibers (BCF). Hexagonal phase CdS nanocrystals were achieved via a simple hydrothermal reaction between CdCl{sub 2} and thiourea at relatively low temperature. The prepared pristine BCF and the CdS/BCF hybrid nanofibers were characterized by transmission electron microscopy (TEM), X-ray diffraction (XRD), thermogravimetric analysis (TGA), UV-vis absorption spectroscopy (UV-vis), and X-ray photoelectron spectroscopy (XPS). The results reveal that the CdS nanoparticles were homogeneously deposited on the BCF surface and stabilized via coordination effect. The CdS/BCF hybrid nanofibers demonstrated high-efficiency photocatalysis with 82% methyl orange (MO) degradation after 90 min irradiation and good recyclability. The results indicate that the CdS/BCF hybrid nanofibers are promising candidate as robust visible light responsive photocatalysts.

  10. 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.

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

    International Nuclear Information System (INIS)

    This paper presents the preparation of epoxy/inorganic-nanoparticle hybrid materials synthesized from diglycidyl ether of bisphenol A and colloidal titania (TiO2) 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 TiO2 to hybrid films. The refractive index at 633 nm increased from 1.450 to 1.639 as the TiO2 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

  12. Porous carbon protected magnetite and silver hybrid nanoparticles: morphological control, recyclable catalysts, and multicolor cell imaging.

    Science.gov (United States)

    Wang, Hui; Shen, Jing; Li, Yingyu; Wei, Zengyan; Cao, Guixin; Gai, Zheng; Hong, Kunlun; Banerjee, Probal; Zhou, Shuiqin

    2013-10-01

    A simple and facile synthetic strategy is developed to prepare a new class of multifunctional hybrid nanoparticles (NPs) that can integrate a magnetic core with silver nanocrystals embedded in porous carbon shell. The method involves a one-step solvothermal synthesis of Fe3O4@C template NPs with Fe3O4nanocrystals in the core protected by a porous carbon shell, followed by loading and in situ reduction of silver ions in the carbon shell in water at room temperature. The core-satellite and dumbbell-like nanostructures of the resulted Fe3O4@C-Ag hybrid NPs can be readily controlled by loading amount of silver ions. The hybrid NPs can efficiently catalyze the reduction reaction of organic dyes in water. The easy magnetic separation and high stability of the catalytically active silver nanocrystals embedded in the carbon shell enable the hybrid NPs to be recycled for reuse as catalysts. The hybrid NPs can also overcome cellular barriers to enter the intracellular region and light up the mouse melanoma B16F10 cells in multicolor modal, with no cytotoxicity. Such porous carbon protected Fe3O4@C-Ag hybrid NPs with controllable nanostructures and a combination of magnetic and noble metallic components have great potential for a broad range of applications in the catalytic industry and biomedical field. PMID:24001139

  13. 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.

  14. 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.

  15. Controlled Dissolution of Phenytoin by Hybridizing with Silica Nanoparticles

    International Nuclear Information System (INIS)

    A sparingly soluble model drug, phenytoin (5,5-diphenyl-hydantoin, denoted as PT), was incorporated during or after hydrolysis and polycondensation of tetra orthoethyl silicate (TEOS) to obtain silica-drug hybrids. We also compare the hybrids obtained by sol-gel process with those obtained by simple adsorption on nonporous silica particles. The initial rate of dissolution in water increases by a factor of 40 with respect to the intact PT by aging silica before drug addition. The IR results show that νC=O in the position 2 of PT and νN-H shift toward the higher wavenumber, showing that intermolecular hydrogen bonds between C=O and N-H are loosened or broken to form new hydrogen bonds between C=O in PT and Si-OH in silica. The dissolution rate of PT is determined by the degree of the breakage of hydrogen bonds between PT molecules and the intensity of the interaction between silica and PT

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

    International Nuclear Information System (INIS)

    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

  17. 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

  18. 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.

  19. Hybrid chitosan–Pluronic F-127 films with BaTiO3:Co nanoparticles: Synthesis and properties

    International Nuclear Information System (INIS)

    In this study, magnetic BaTiO3: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 BaTiO3: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 BaTiO3: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

  20. Study of ZnO nanoparticles based hybrid nanocomposites for optoelectronic applications

    Science.gov (United States)

    Belhaj, Marwa; Dridi, Cherif; Elhouichet, Habib; Valmalette, Jean Cristophe

    2016-03-01

    We report on the effect of nanoparticle concentration on the performance of hybrid polymer/zinc oxide (ZnO) thin films. We used scanning electron microscopy, atomic force microscopy, Raman spectroscopy, UV-Vis absorption, and photoluminescence spectroscopies to study the morphology, structure, and optical behavior of the different nanocomposites. Topographical analysis has shown that ZnO nanoparticles (n-ZnO) affect the morphology of thin film and indicated that the roughness of the samples was found to increase with the concentration of n-ZnO until 50 wt. %, then decreased for higher concentration. A clear contribution of nanoparticles in the nanocomposites absorption has been demonstrated in UV-Vis spectra with maintaining the absorption features of the polymer. Further investigations have revealed a decrease in band gap energy (Eg) with increasing nanoparticles amount in the polymer showing size variation depending on n-ZnO. The structures have shown overlapping emission bands from both ZnO and the polymer. The origins of this emission and its evolution with nanoparticles concentration were also discussed.

  1. 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.

  2. 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

  3. 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

  4. 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

  5. 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.

  6. 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.

  7. 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.

  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. PMID:27288818

  9. 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.

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

    International Nuclear Information System (INIS)

    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.

  11. 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

  12. 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

  13. 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

  14. 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.

  15. Memory effects in annealed hybrid gold nanoparticles/block copolymer bilayers

    Directory of Open Access Journals (Sweden)

    Ruffino Francesco

    2011-01-01

    Full Text Available Abstract We report on the use of the self-organization process of sputtered gold nanoparticles on a self-assembled block copolymer film deposited by horizontal precipitation Langmuir-Blodgett (HP-LB method. The morphology and the phase-separation of a film of poly-n-butylacrylate-block-polyacrylic acid (PnBuA-b-PAA were studied at the nanometric scale by using atomic force microscopy (AFM and Time of Flight Secondary Ion Mass Spectrometry (TOF-SIMS. The templating capability of the PnBuA-b-PAA phase-separated film was studied by sputtering gold nanoparticles (NPs, forming a film of nanometric thickness. The effect of the polymer chain mobility onto the organization of gold nanoparticle layer was assessed by heating the obtained hybrid PnBuA-b-PAA/Au NPs bilayer at T >Tg. The nanoparticles' distribution onto the different copolymer domains was found strongly affected by the annealing treatment, showing a peculiar memory effect, which modifies the AFM phase response of the Au NPs layer onto the polar domains, without affecting their surfacial composition. The effect is discussed in terms of the peculiar morphological features induced by enhanced mobility of polymer chains on the Au NPs layer.

  16. Rheological behavior of clay-nanoparticle hybrid-added bentonite suspensions: specific role of hybrid additives on the gelation of clay-based fluids.

    Science.gov (United States)

    Jung, Youngsoo; Son, You-Hwan; Lee, Jung-Kun; Phuoc, Tran X; Soong, Yee; Chyu, Minking K

    2011-09-01

    Two different types of clay nanoparticle hybrid, iron oxide nanoparticle clay hybrid (ICH) and Al(2)O(3)-SiO(2) nanoparticle clay hybrid (ASCH), were synthesized and their effects on the rheological properties of aqueous bentonite fluids in steady state and dynamic state were explored. When ICH particles were added, bentonite particles in the fluid cross-link to form relatively well-oriented porous structure. This is attributed to the development of positively charged edge surfaces in ICH that leads to strengthening of the gel structure of the bentonite susensions. The role of ASCH particles on the interparticle association of the bentonite fluids is different from that of ICH and sensitive to pH. As pH of ASCH-added bentonite suspensions increased, the viscosity, yield stress, storage modulus, and flow stress decreased. In contrast, at low pH, the clay suspensions containing ASCH additives were coagulated and their rheological properties become close to those of ICH added bentonite fluids. A correlation between the net surface charge of the hybrid additives and the rheological properties of the fluids indicates that the embedded nanoparticles within the interlayer space control the variable charge of the edge surfaces of the platelets and determine the particles association behavior of the clay fluids. PMID:21888313

  17. Electrogenerated chemiluminescence detection for deoxyribonucleic acid hybridization based on gold nanoparticles carrying multiple probes

    International Nuclear Information System (INIS)

    A novel sensitive electrogenerated chemiluminescence (ECL) method for the detection deoxyribonucleic acid (DNA) hybridization based on gold nanoparticles carrying multiple probes was developed. Ruthenium bis(2,2'-bipyridine)(2,2'-bipyridine-4,4'-dicarboxylic acid)-N-hydroxysuccinimide ester (Ru(bpy)2(dcbpy)NHS) was used as a ECL label and gold nanoparticle as a carrier. Probe single strand DNA (ss-DNA) was self-assembled at the 3'-terminal with a thiol group to the surface of gold nanoparticle and covalently labeled at the 5'-terminal of a phosphate group with Ru(bpy)2(dcbpy)NHS and the resulting conjugate (Ru(bpy)2(dcbpy)NHS)-ss-DNA-Au, was taken as a ECL probe. When target analyte ss-DNA was immobilized on a gold electrode by self-assembled monolayer technique and then hybridized with the ECL probe to form a double-stranded DNA (ds-DNA), a strong ECL response was electrochemically generated. The ECL intensity was linearly related to the concentration of the complementary sequence (target ss-DNA) in the range from 1.0 x 10-11 to 1.0 x 10-8 mol L-1, and the linear regression equation was S = 57301 + 4579.6 lg C (unit of C is mol L-1). A detection limit of 5.0 x 10-12 mol L-1 for target ss-DNA was achieved. The ECL signal generated from many reporters of ECL probe prepared is greatly amplified, compared to the convention scheme which is based on one reporter per hybridization event

  18. Synthesis of Silica Hybrid Nanoparticles and the Effect of Their Addition on the Hardness of the Dental Nanocomposites

    Directory of Open Access Journals (Sweden)

    Roziamarni Che Abdul Aziz

    2012-01-01

    Full Text Available The objective of this study is to investigate the effect of silica hybrid nanoparticles on the hardness of the dental nanocomposites. The silica hybrid nanoparticles were synthesized by sol-gel method. The powders were modified with 3-methacryloxy-propyltrimethoxy silane (γ-MPS either by co-condensation method or one-pot method. The silanized silica were then mixed with  a mixture of bisglycidyl methacrylate (BisGMA, triethylene glycol methacrylate (TEGDMA, camphorquinone (CQ and dimethylaminoethyl methacrylate (DMAEMA to form dental nanocomposites.  The hardness of the nanocomposites were determined using vickers hardness. The results shown that hardness of the dental composites using silica hybrid nanoparticles synthesized via one-pot method was higher compared to the synthesized via co-condensation method. Transmission Electron Microscope (TEM, and Fourier Transform Infrared Spectroscopy (FTIR were used for characterization.

  19. A facile route to synthesize core/shell structured carbon/magnetic nanoparticles hybrid and their magnetic properties

    International Nuclear Information System (INIS)

    Graphical abstract: Controllable synthesis of core/shell structured carbon/magnetic nanoparticles hybrid and their tunable magnetic properties. - Highlights: • The paper reports a simple route for core/shell structured carbon/magnetic nanoparticles hybrid. • By controlling the temperature, Fe3O4@CNCs, Fe@HCNTs and Fe@LCNTs were produced selectively. • The magnetic properties of the obtained core/shell structured hybrid could be tuned effectively. - Abstract: By controlling the pyrolysis temperature, core/shell structured Fe3O4/carbon nanocages, Fe/helical carbon nanotubes and Fe/low helicity of carbon nanotubes could be synthesized selectively over Fe2O3 nanotubes generated by a hydrothermal method. The transmission electron microscopic and scanning electron microscopic investigations revealed that the efficiency of generating core/shell structured hybrid was high, exceeding 90%. Because of the magnetic nanoparticles tightly wrapped in graphitic layers, the obtained core/shell structured hybrids showed high stability and good magnetic properties. And the magnetic properties of the obtained core/shell structured hybrid could be tuned by the decomposition temperature and time. Therefore, a simple, inexpensive and environment-benign route was proposed to produce magnetism-tunable core/shell structured hybrid in large quantities

  20. 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.

  1. 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...... transfection-competent siRNA-DOTAP lipoplexes from the LPNs. Based on these results, we suggest a model for the nanostructural characteristics of the LPNs, in which the siRNA is organized in lamellar superficial assemblies and/or as complexes entrapped in the polymeric matrix....

  2. 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

  3. 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

  4. 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

  5. Self-assembly of diblock copolymer-maghemite nanoparticle hybrid thin films.

    Science.gov (United States)

    Yao, Yuan; Metwalli, Ezzeldin; Moulin, Jean-François; Su, Bo; Opel, Matthias; Müller-Buschbaum, Peter

    2014-10-22

    The arrangement of maghemite (γ-Fe2O3) nanoparticles (NPs) in poly(styrene-d8-block-n-butyl methacrylate) P(Sd-b-BMA) diblock copolymer (DBC) films via a self-assembly process was investigated toward the fabrication of highly ordered maghemite-polymer hybrid thin films. The resulting thin films exhibited a perforated lamella with an enrichment layer containing NPs as investigated with X-ray reflectometry, scanning electron microscopy, atomic force microscopy, and time-of-flight grazing incidence small angle neutron scattering as a function of the NP concentrations. The NPs were selectively deposited in the PSd domains of the DBC during the microphase separation process. At low NP concentrations, the incorporation of the NPs within the DBC thin films resulted in an enhanced microphase separation process and formation of highly oriented and ordered nanostructured hybrid films. At higher NP concentrations, the aggregation of the NPs was dominating and large sized metal oxide clusters were observed. The superparamagnetic properties of the metal oxide-polymer hybrid films at various NP concentrations were probed by a superconducting quantum interference device magnetometer, which shows that the hybrid films are highly attractive for optical devices, magnetic sensors, and magnetic recording devices. PMID:25243575

  6. Iodinated silica/porphyrin hybrid nanoparticles for X-ray computed tomography/fluorescence dual-modal imaging of tumors

    OpenAIRE

    Koichiro Hayashi; Sakamoto Wataru; Toshinobu Yogo

    2014-01-01

    Silica nanoparticles containing covalently linked iodine and a near-infrared (NIR) fluorescence dye, namely porphyrin, have been synthesized through a one-pot sol–gel reaction. These particles are called iodinated silica/porphyrin hybrid nanoparticles (ISP HNPs). The ISP HNPs have both high X-ray absorption coefficient and NIR fluorescence. The ISP HNPs modified with folic acid (FA) and polyethylene glycol (PEG), denoted as FA-PEG-ISP HNPs, enabled the successful visualization of tumors in mi...

  7. 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.

  8. 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.

  9. 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

  10. Fabrication, Light Emission, and Magnetism of Silica Nanoparticles Hybridized with AIE Luminogens and Inorganic Nanostructures

    Science.gov (United States)

    Faisal, Mahtab

    Much research efforts have been devoted in developing new synthetic approaches for fluorescent silica nanoparticles (FSNPs) due to their potential high-technological applications. However, light emissions from most of the FSNPs prepared so far have been rather weak. This is due to the emission quenching caused by the aggregation of fluorophores in the solid state. We have observed a novel phenomenon of aggregation-induced emission (AIE): a series of propeller-shaped molecules such as tetraphenylethene (TPE) and silole are induced to emit efficiently by aggregate formation. Thus, they are ideal fluorophors for the construction of FSNPs and my thesis work focuses on the synthesis of silica nanoparticles containing these luminogens and magnetic nanostructures. Highly emissive FSNPs with core-shell structures are fabricated by surfactant-free sol-gel reactions of tetraphenylethene- (TPE) and silole-functionalized siloxanes followed by the reactions with tetraethoxysilane. The FSNPs are uniformly sized, surface-charged and colloidally stable. The diameters of the FSNPs are tunable in the range of 45--295 nm by changing the reaction conditions. Whereas their TPE and silole precursors are non-emissive, the FSNPs emit strong visible lights, thanks to the novel aggregation-induced emission characteristics of the TPE and silole aggregates in the hybrid nanoparticles. The FSNPs pose no toxicity to living cells and can be utilized to selectively image cytoplasm of HeLa cells. Applying the same tool in the presence of citrate-coated magnetite nanoparticles, uniform magnetic fluorescent silica nanoparticles (MFSNPs) with smooth surfaces are fabricated. These particles exhibit appreciable surface charges and hence good colloidal stability. They are superparamagnetic, exhibiting no hysteresis at room temperature. UV irradiation of a suspension of MFSNPs in ethanol gives strong blue and green emissions. The MFSNPs can selectively stain the cytoplasmic regions of the living cells

  11. 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.

  12. 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.

  13. Design and feasibility of high temperature nanoparticle fluid filter in hybrid thermal/photovoltaic concentrating solar power

    Science.gov (United States)

    DeJarnette, Drew; Brekke, Nick; Tunkara, Ebrima; Hari, Parameswar; Roberts, Kenneth; Otanicar, Todd

    2015-09-01

    A nanoparticle fluid filter used with concentrating hybrid solar/thermal collector design is presented. Nanoparticle fluid filters could be situated on any given concentrating system with appropriate customized engineering. This work shows the design in the context of a trough concentration system. Geometric design and physical placement in the optical path was modeled using SolTrace. It was found that a design can be made that blocks 0% of the traced rays. The nanoparticle fluid filter is tunable for different concentrating systems using various PV cells or operating at varying temperatures.

  14. 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

    ) grafted 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...... two-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...

  15. Physical stability, biocompatibility and potential use of hybrid iron oxide-gold nanoparticles as drug carriers

    International Nuclear Information System (INIS)

    Hybrid nanoparticles (HNPs) such as iron oxide-gold nanoparticles are currently being exploited for their potential application in image-guided therapies. However, little investigation has been carried out into their physical or chemical stability and potential cytotoxicity in biological systems. Here, we determine the HNPs physical stability over 6 months and chemical stability in physiological conditions, and estimate the biological activity of uncoated and poly(ethylene glycol) coated nanoparticles on human pancreatic adenocarcinoma (BxPC-3) and differentiated human monocyte cells (U937). The potential of these HNPs to act as drug carrier vehicles was determined using the model drug 6-Thioguanine (6-TG). The data showed that the HNPs maintained their structural integrity both physically and chemically throughout the duration of the studies. In addition, negligible cytotoxicity or free radical production was observed in the cell lines tested. The 6-TG was successfully conjugated; with a ratio of 3:1:10 Fe:Au:6-TG (wt:wt:wt). After incubation with BxPC-3 cells, enhanced cellular uptake was reported with the 6-TG-conjugated HNPs compared with free drug along with a 10-fold decrease in IC50. This exciting data highlights the potential of HNPs for use in image-guided drug delivery.

  16. 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

  17. 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

  18. 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

  19. 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

  20. 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.

  1. 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

  2. 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.

  3. 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.

  4. 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

  5. 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.

  6. 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.

  7. 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.

  8. 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

  9. Graphene oxide and shape-controlled silver nanoparticle hybrids for ultrasensitive single-particle surface-enhanced Raman scattering (SERS) sensing

    Science.gov (United States)

    Fan, Wei; Lee, Yih Hong; Pedireddy, Srikanth; Zhang, Qi; Liu, Tianxi; Ling, Xing Yi

    2014-04-01

    Graphene oxide (GO) is an emerging material for surface-enhanced Raman scattering (SERS) due to its strong chemical enhancement. Studying the SERS performance of plasmonic nanoparticle/GO hybrid materials at the single particle level is crucial for direct probing of the chemical effect of GO on plasmonic nanoparticles. In this work, we integrate GO and shape-controlled Ag nanoparticles to create hybrid nanomaterials, and the chemical enhancement arising from GO is investigated using single-particle SERS measurements. Ag nanoparticle@GO hybrid nanostructures are prepared by assembling Ag nanoparticles, including spheres, cubes and octahedra with GO sheets. The SERS behaviors of the hybrid nanostructures are characterized, and 2-3 times enhanced SERS intensities are detected from the Ag nanoparticle@GO hybrid nanostructures as compared to pure Ag nanoparticles. Furthermore, we probe the mechanism of SERS enhancement in the hybrid nanostructures by changing the surface coverage of GO on Ag octahedra, by using reduced GO in place of GO as well as by using probe molecules of different electronegativities. This hybrid system is an excellent candidate for single-particle SERS sensors. Sub-nanomolar levels of aromatic molecules are detected using a single Ag/GO hybrid nanomaterial. This as-prepared GO and shape-controlled Ag nanoparticle hybrid is capable of serving as a high performance SERS platform, providing new opportunities for efficient chemical and biological sensing applications.Graphene oxide (GO) is an emerging material for surface-enhanced Raman scattering (SERS) due to its strong chemical enhancement. Studying the SERS performance of plasmonic nanoparticle/GO hybrid materials at the single particle level is crucial for direct probing of the chemical effect of GO on plasmonic nanoparticles. In this work, we integrate GO and shape-controlled Ag nanoparticles to create hybrid nanomaterials, and the chemical enhancement arising from GO is investigated using single

  10. A novel thermal and pH responsive drug delivery system based on ZnO@PNIPAM hybrid nanoparticles

    Energy Technology Data Exchange (ETDEWEB)

    Tan, Licheng; Liu, Jian; Zhou, Weihua [Department of Chemistry, Nanchang University, Nanchang 330031 (China); Wei, Junchao, E-mail: weijunchao@ncu.edu.cn [Department of Chemistry, Nanchang University, Nanchang 330031 (China); State Key Laboratory of Molecular Engineering of Polymers, Department of Macromolecular Science, Fudan University, 220 Handan Road, Shanghai 200433 (China); Peng, Zhiping [Department of Chemistry, Nanchang University, Nanchang 330031 (China)

    2014-12-01

    A smart ZnO@PNIPAM hybrid was prepared by grafting thermal responsive poly(N-isopropylacrylamide) (PNIPAM) on zinc oxide (ZnO) nanoparticles via surface-initiated atom transfer radical polymerization (ATRP). The thermal gravimetric analysis (TGA) shows that the grafting amount of PNIPAM was about 38%, and the SEM images show that the PNIPAM chains can prevent the aggregation of ZnO nanoparticles. The responsive properties of ZnO@PNIPAM were measured by photoluminescence spectra, and the results demonstrate that the PNIPAM chains grafted on ZnO surfaces can realize reversible thermal responsive and photoluminescence properties. An anticancer drug, doxorubicin (Dox), was used as a model drug and loaded into the hybrid nanoparticles, and an in vitro drug release test implied that ZnO@PNIPAM could work as a thermal responsive drug delivery system. Furthermore, pH sensitive drug releases were carried out in acetate buffer at pH 5.0 and pH 6.0 and in water at pH 7.0, and the results showed evident pH dependency, showing its pH responsive properties. - Graphical abstract: In this manuscript, thermal responsive poly(N-isopropylacrylamide) (PNIPAM) was grafted on the surface of ZnO nanoparticles. The obtained ZnO@PNIPAM hybrid showed reversible thermal responsive photoluminescent properties, and can also work as a thermal and pH responsive drug delivery system. - Highlights: • The ZnO@PNIPAM hybrid was prepared via ATRP. • The ZnO@PNIPAM hybrid showed thermal responsive properties. • The ZnO@PNIPAM hybrid can work as a thermal and pH responsive drug delivery system.

  11. 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.

  12. 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.

  13. Hybrid silver nanoparticle/conjugated polyelectrolyte nanocomposites exhibiting controllable metal-enhanced fluorescence

    Science.gov (United States)

    Wang, Xiaoyu; He, Fang; Zhu, Xi; Tang, Fu; Li, Lidong

    2014-03-01

    Metal-enhanced fluorescence of conjugated polyelectrolytes (CPs) is realized using a simple, green hybrid Ag nanocomposite film. Ag nanoparticles (Ag NPs) are pre-prepared by sodium citrate reduction and incorporated into agarose by mixing to form an Ag-containing agarose film (Ag@agarose). Through variation of the amount of Ag NPs in the Ag@agarose film as well as the thickness of the interlayer between CPs and the Ag@agarose film prepared of layer-by-layer assembly of chitosan and sodium alginate, a maximum 8.5-fold increase in the fluorescence of CPs is obtained. After introducing tyrosinase, this system also can be used to detect phenolic compounds with high sensitivity and good visualization under ultraviolet light.

  14. 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

  15. 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.

  16. Synthesis and Catalytic Features of Hybrid Metal Nanoparticles Supported on Cellulose Nanofibers

    Directory of Open Access Journals (Sweden)

    Hirotaka Koga

    2011-11-01

    Full Text Available The structural and functional design of metal nanoparticles has recently allowed remarkable progress in the development of high-performance catalysts. Gold nanoparticles (AuNPs are among the most innovative catalysts, despite bulk Au metal being regarded as stable and inactive. The hybridization of metal NPs has attracted major interest in the field of advanced nanocatalysts, due to electro-mediated ligand effects. In practical terms, metal NPs need to be supported on a suitable matrix to avoid any undesirable aggregation; many researchers have reported the potential of polymer-supported AuNPs. However, the use of conventional polymer matrices make it difficult to take full advantage of the inherent properties of the metal NPs, since most of active NPs are imbedded inside the polymer support. This results in poor accessibility for the reactants. Herein, we report the topochemical synthesis of Au and palladium (Pd bimetallic NPs over the surfaces of 2,2,6,6-tetramethylpiperidine-1-oxyl (TEMPO-oxidized cellulose nanofibers (TOCNs, and their exceptional catalytic performance. Highly-dispersed AuPdNPs were successfully synthesized in situ on the crystal surfaces of TOCNs with a very high density of carboxylate groups. The AuPdNPs@TOCN nanocomposites exhibit excellent catalytic efficiencies in the aqueous reduction of 4-nitrophenol to 4-aminophenol, depending on the molar ratios of Au and Pd.

  17. 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.

  18. 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.

  19. 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.

  20. Hybrid gold-iron oxide nanoparticles as a multifunctional platform for biomedical application

    Directory of Open Access Journals (Sweden)

    Hoskins Clare

    2012-06-01

    Full Text Available Abstract Background Iron oxide nanoparticles (IONPs have increasing applications in biomedicine, however fears over long term stability of polymer coated particles have arisen. Gold coating IONPs results in particles of increased stability and robustness. The unique properties of both the iron oxide (magnetic and gold (surface plasmon resonance result in a multimodal platform for use as MRI contrast agents and as a nano-heater. Results Here we synthesize IONPs of core diameter 30 nm and gold coat using the seeding method with a poly(ethylenimine intermediate layer. The final particles were coated in poly(ethylene glycol to ensure biocompatibility and increase retention times in vivo. The particle coating was monitored using FTIR, PCS, UV–vis absorption, TEM, and EDX. The particles appeared to have little cytotoxic effect when incubated with A375M cells. The resultant hybrid nanoparticles (HNPs possessed a maximal absorbance at 600 nm. After laser irradiation in agar phantom a ΔT of 32°C was achieved after only 90 s exposure (50 μgmL-1. The HNPs appeared to decrease T2 values in line with previously clinically used MRI contrast agent Feridex®. Conclusions The data highlights the potential of these HNPs as dual function MRI contrast agents and nano-heaters for therapies such as cellular hyperthermia or thermo-responsive drug delivery.

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

    International Nuclear Information System (INIS)

    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. (paper)

  2. 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

  3. 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

  4. 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

  5. Multi-functional hybrid coatings containing silica nanoparticles and anti-corrosive acrylate monomer for scratch and corrosion resistance

    International Nuclear Information System (INIS)

    Multi-functional hybrid coatings having both anti-corrosion and scratch resistance were prepared from modified silica nanoparticles and functional acrylates. To improve the dispersion properties of silica nanoparticles in the organic/inorganic hybrid coatings, the surface of the nanoparticles was modified with γ-methacryloxypropyltrimethoxysilane. The coating solution could be prepared by mixing modified silica nanoparticles, tetrasiloxane acrylate, di-acrylate monomer containing an anti-corrosion functional group, acrylic acid, and an initiator in a solvent. The mixture was then dip-coated on iron substrates and finally polymerized by ultraviolet (UV) irradiation. Corrosion and scratch resistance of the coated iron was evaluated by electrochemical impedance spectroscopy (EIS) and a pencil hardness test, respectively. From the EIS results, the coatings with tetrasiloxane acrylate and di-acrylate did not show any decrease in impedance or phase angle, even after 50 days' exposure to 0.1 M NaCl electrolyte, whereas the conventional acrylate coatings started to fail after only 24 h. A hybrid coating containing the amine-quinone functional group exhibited excellent corrosion protection properties with 4-5H pencil hardness.

  6. Multi-functional hybrid coatings containing silica nanoparticles and anti-corrosive acrylate monomer for scratch and corrosion resistance

    Science.gov (United States)

    Seo, Ji Yeon; Han, Mijeong

    2011-01-01

    Multi-functional hybrid coatings having both anti-corrosion and scratch resistance were prepared from modified silica nanoparticles and functional acrylates. To improve the dispersion properties of silica nanoparticles in the organic/inorganic hybrid coatings, the surface of the nanoparticles was modified with γ-methacryloxypropyltrimethoxysilane. The coating solution could be prepared by mixing modified silica nanoparticles, tetrasiloxane acrylate, di-acrylate monomer containing an anti-corrosion functional group, acrylic acid, and an initiator in a solvent. The mixture was then dip-coated on iron substrates and finally polymerized by ultraviolet (UV) irradiation. Corrosion and scratch resistance of the coated iron was evaluated by electrochemical impedance spectroscopy (EIS) and a pencil hardness test, respectively. From the EIS results, the coatings with tetrasiloxane acrylate and di-acrylate did not show any decrease in impedance or phase angle, even after 50 days' exposure to 0.1 M NaCl electrolyte, whereas the conventional acrylate coatings started to fail after only 24 h. A hybrid coating containing the amine-quinone functional group exhibited excellent corrosion protection properties with 4-5H pencil hardness.

  7. Targeted delivery of 10-hydroxycamptothecin to human breast cancers by cyclic RGD-modified lipid–polymer hybrid nanoparticles

    International Nuclear Information System (INIS)

    Lipid–polymer hybrid nanoparticles (NPs) combining the positive attributes of both liposomes and polymeric NPs are increasingly being considered as promising candidates to carry therapeutic agents safely and efficiently into targeted sites. Herein, a modified emulsification technique was developed and optimized for the targeting lipid–polymer hybrid NPs fabrication; the surface properties and stability of the hybrid NPs were systematically investigated, which confirmed that the hybrid NPs consisted of a poly (lactide-co-glycolide) core with ∼90% surface coverage of the lipid monolayer and a ∼4.4 nm hydrated polyethylene glycol (PEG) shell. Optimization results showed that the lipid:polymer mass ratio and the lipid-PEG:lipid molar ratio could affect the size, lipid association efficiency and stability of hybrid NPs. Furthermore, a model chemotherapy drug, 10-hydroxycamptothecin, was encapsulated into hybrid NPs with a higher drug loading compared to PLGA NPs. Surface modification of the lipid layer and the PEG conjugated targeting ligand did not affect their drug release kinetics. Finally, the cytotoxicity and cellular uptake studies indicated that the lipid coverage and the c(RGDyk) conjugation of the hybrid NPs gained a significantly enhanced ability of cell killing and endocytosis. Our results suggested that lipid–polymer hybrid NPs prepared by the modified emulsion technique have great potential to be utilized as an engineered drug delivery system with precise control ability of surface targeting modification. (paper)

  8. Mildly reduced graphene oxide-Ag nanoparticle hybrid films for surface-enhanced Raman scattering

    Science.gov (United States)

    Li, Xiaocheng; Tay, Beng Kang; Li, Junshuai; Tan, Dunlin; Tan, Chong Wei; Liang, Kun

    2012-04-01

    Large-area mildly reduced graphene oxide (MR-GO) monolayer films were self-assembled on SiO2/Si surfaces via an amidation reaction strategy. With the MR-GO as templates, MR-GO-Ag nanoparticle (MR-GO-Ag NP) hybrid films were synthesized by immersing the MR-GO monolayer into a silver salt solution with sodium citrate as a reducing agent under UV illumination. SEM image indicated that Ag NPs with small interparticle gap are uniformly distributed on the MR-GO monolayer. Raman spectra demonstrated that the MR-GO monolayer beneath the Ag NPs can effectively quench the fluorescence signal emitted from the Ag films and dye molecules under laser excitation, resulting in a chemical enhancement (CM). The Ag NPs with narrow gap provided numerous hot spots, which are closely related with electromagnetic mechanism (EM), and were believed to remarkably enhance the Raman signal of the molecules. Due to the co-contribution of the CM and EM effects as well as the coordination mechanism between the MR-GO and Ag NPs, the MR-GO-Ag NP hybrid films showed more excellent Raman signal enhancement performance than that of either Ag films or MR-GO monolayer alone. This will further enrich the application of surface-enhanced Raman scattering in molecule detection.

  9. 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

  10. 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

  11. 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

  12. 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.

  13. 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

  14. 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.

  15. 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.

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

    International Nuclear Information System (INIS)

    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

  17. 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.

  18. 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

  19. 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.

  20. 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

  1. 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. PMID:26609926

  2. 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...

  3. 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

  4. Preparation and characterization of hybrid material consisting of gold nanoparticles and poly(N-ethyl-2-ethynyl-pyridinium iodide)

    Czech Academy of Sciences Publication Activity Database

    Dammer, Ondřej; Šišková, Karolína; Vlčková, B.; Slaný, L.; Pfleger, Jiří

    Darmstadt: Elsevier in association with Solid State Sciences, 2008 - (Albert, B.; Attfield, J.; Grin, Y.; Ruck, M.). P3-48_1-P3-48_2 [International Conference on Inorganic Materials /6./. 28.09.2008-30.09.2008, Dresden] R&D Projects: GA AV ČR KAN100500652 Institutional research plan: CEZ:AV0Z40500505 Keywords : hybrid materials * plasmonic nanoparticles * pi-conjugated polymers Subject RIV: CF - Physical ; Theoretical Chemistry http://www.im-conference.elsevier.com/

  5. Morphology and Properties of a Hybrid Organic-Inorganic System: Al Nanoparticles Embedded Into CuPc Thin Film

    OpenAIRE

    Molodtsova, Olga; Aristova, I. M.; Babenkov, S. V.; Vilkov, O. V.; Aristov, Victor

    2014-01-01

    The evolution of the morphology and the electronic structure of the hybrid organic-inorganic system composed of aluminum nanoparticles (NPs) distributed in an organic semiconductor matrix—copper phthalocyanine (CuPc)—as a function of nominal aluminum content was studied by transmission electron microscopy and by photoemission spectroscopy methods. The aluminum atoms deposited onto the CuPc surface diffuse into the organic matrix and self-assemble to NPs in a well-defined manner with a narrow ...

  6. 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...

  7. Resonant Infrared Matrix-Assisted Pulsed Laser Evaporation Of Inorganic Nanoparticles And Organic/Inorganic Hybrid Nanocomposites

    International Nuclear Information System (INIS)

    In this research, resonant infrared matrix-assisted pulsed laser evaporation (RIR-MAPLE) has been used to deposit different classes of inorganic nanoparticles, including bare, un-encapsulated ZnO and Au nanoparticles, as well as ligand-encapsulated CdSe colloidal quantum dots (CQDs). RIR-MAPLE has been used for thin-film deposition of different organic/inorganic hybrid nanocomposites using some of these inorganic nanoparticles, including CdSe CQD-poly[2-methoxy-5-(2'-ethylhexyloxy )-1,4-(1-cyanovinylene)phenylene](MEH-CN-PPV) nanocomposites and Au nanoparticle-poly(methyl methacrylate)(PMMA) nanocomposites. The unique contribution of this research is that a technique is demonstrated for the deposition of organic-based thin-films requiring solvents with bond energies that do not have to be resonant with the laser energy. By creating an emulsion of solvent and ice in the target, RIR-MAPLE using a 2.94 μm laser can deposit most material systems because the hydroxyl bonds in the ice component of the emulsion matrix are strongly resonant with the 2.94 μm laser. In this way, the types of materials that can be deposited using RIR-MAPLE has been significantly expanded. Furthermore, materials with different solvent bond energies can be co-deposited without concern for material degradation and without the need to specifically tune the laser energy to each material solvent bond energy, thereby facilitating the realization of organic/inorganic hybrid nanocomposite thin-films. In addition to the structural characterization of the inorganic nanoparticle and hybrid nanocomposite thin-films deposited using this RIR-MAPLE technique, optical characterization is presented to demonstrate the potential of such films for optoelectronic device applications.

  8. 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

  9. Gold Nanoparticle@Polyhedral Oligomeric Silsesquioxane Hybrid Scaffolds in Microfluidic Format – Highly Efficient and Green Catalytic Platforms

    Science.gov (United States)

    Scholder, Pascal; Hafner, Martina; Hassel, Achim W.; Nischang, Ivo

    2016-01-01

    Abstract We report on the preparation of new hybrid organic–inorganic multiporous monolithic capillary columns carrying gold nanoparticles of 5, 10, 50, and 100 nm size and their use as flow‐through catalytic platforms for aqueous liquid‐phase reduction reactions. We found that the flow‐through performance of the reactors depends not only on the size of the gold nanoparticles but also on the interplay of the pore size of the scaffolds and the catalytically available gold surface within the system, that is, loading an increased number of gold nanoparticles of smaller size does not necessarily result in strictly improved performance. This indicates the importance of the interplay between the nanopore size of the scaffolds and the catalytically active gold surface existing within the system. Demonstration of the highly efficient catalytic flow‐through operation within seconds and the repeated use of the reactors without loss of performance indicates their excellent suitability as microfluidic device elements.

  10. Fabrication of Uniform Janus Micorparticles by Photopolymerization-Driven Phase Separation and their Asymmetric Hybridization with Metal Nanoparticles

    Science.gov (United States)

    Cho, Jangwoo; Kim, Jeong Won; Kim, Jin Woong

    2015-03-01

    In the field of colloid science, there is growing interest in synthesis of anisotropic particles, since they are desirable for controlling light scattering. These anisotropic particles have been developed by using sophisticated techniques, including clusterization, stamping, microfluidics, and controlled nucleation and precipitation. This study introduces a facile approach for fabrication of uniform Janus microparticles with anisotropic phases as well as selected surface chemistry. The technique we employed to synthesize these microparticles was the seeded swelling and polymerization method, in which complete compartmentalization of the particles into two distinct phases occurred upon polymerizing the monomer-swollen droplets. Then, we patched nanoparticles, such as gold nanoparticles and magnetic nanoparticles, onto one of the compartmentalized phases of the Janus microparticles. Finally we demonstrate that these asymmetrically hybridized Janus microparticles are of great importance and play a role in the designated colloidal 2D array.

  11. Folate-modified lipid–polymer hybrid nanoparticles for targeted paclitaxel delivery

    Directory of Open Access Journals (Sweden)

    Zhang L

    2015-03-01

    Full Text Available Linhua Zhang,1 Dunwan Zhu,1 Xia Dong,1 Hongfan Sun,1 Cunxian Song,1 Chun Wang,2 Deling Kong1 1Tianjin Key Laboratory of Biomaterials, Institute of Biomedical Engineering, Peking Union Medical College and Chinese Academy of Medical Sciences, Tianjin, People’s Republic of China; 2Department of Biomedical Engineering, University of Minnesota, Minneapolis, MN, USA Abstract: The purpose of this study was to develop a novel lipid–polymer hybrid drug carrier comprised of folate (FA modified lipid-shell and polymer-core nanoparticles (FLPNPs for sustained, controlled, and targeted delivery of paclitaxel (PTX. The core-shell NPs consist of 1 a poly(ε-caprolactone hydrophobic core based on self-assembly of poly(ε-caprolactone–poly(ethylene glycol–poly(ε-caprolactone (PCL-PEG-PCL amphiphilic copolymers, 2 a lipid monolayer formed with 1,2-distearoyl-sn-glycero-3-phosphoethanolamine-N-[methoxy (polyethylene glycol-2000] (DSPE-PEG2000, 3 a targeting ligand (FA on the surface, and were prepared using a thin-film hydration and ultrasonic dispersion method. Transmission electron microscopy and dynamic light scattering analysis confirmed the coating of the lipid monolayer on the hydrophobic polymer core. Physicochemical characterizations of PTX-loaded FLPNPs, such as particle size and size distribution, zeta potential, morphology, drug loading content, encapsulation efficiency, and in vitro drug release, were also evaluated. Fluorescent microscopy proved the internalization efficiency and targeting ability of the folate conjugated on the lipid monolayer for the EMT6 cancer cells which overexpress folate receptor. In vitro cytotoxicity assay demonstrated that the cytotoxic effect of PTX-loaded FLPNPs was lower than that of Taxol®, but higher than that of PTX-loaded LPNPs (without folate conjugation. In EMT6 breast tumor model, intratumoral administration of PTX-loaded FLPNPs showed similar antitumor efficacy but low toxicity compared to Taxol®. More

  12. Hybrid calcium carbonate/polymer microparticles containing silver nanoparticles as antibacterial agents

    Energy Technology Data Exchange (ETDEWEB)

    Dlugosz, Maciej; Bulwan, Maria; Kania, Gabriela; Nowakowska, Maria; Zapotoczny, Szczepan, E-mail: zapotocz@chemia.uj.edu.pl [Jagiellonian University, Faculty of Chemistry (Poland)

    2012-12-15

    We report here on synthesis and characterization of novel hybrid material consisting of silver nanoparticles (nAgs) embedded in calcium carbonate microparticles ({mu}-CaCO{sub 3}) serving as carriers for sustained release. nAgs are commonly used as antimicrobial agents in many commercial products (textiles, cosmetics, and drugs). Although they are considered to be safe, their interactions with human organisms are still not fully understood; therefore it is important to apply them with caution and limit their presence in the environment. The synthesis of the new material was based on the co-precipitation of CaCO{sub 3} and nAg in the presence of poly(sodium 4-styrenesulfonate). Such designed system enables sustained release of nAg to the environment. This hybrid colloidal material (nAg/{mu}-CaCO{sub 3}) was characterized by microscopic and spectroscopic methods. The release of nAg from {mu}-CaCO{sub 3} microparticles was followed in water at various pH values. Microbiological tests confirmed the effectiveness of these microparticles as an antibacterial agent. Importantly, the material can be stored as a dry powder and subsequently re-suspended in water without the risk of losing its antimicrobial activity. nAg/{mu}-CaCO{sub 3} was applied here to insure bacteriostatic properties of down feathers that may significantly prolong their lifetime in typical applications. Such microparticles may be also used as, e.g., components of coatings and paints protecting various surfaces against microorganism colonization.

  13. Synthesis and Application of Hybrid Polymer Composites Based on Silver Nanoparticles as Corrosion Protection for Line Pipe Steel

    Directory of Open Access Journals (Sweden)

    Ayman M. Atta

    2014-05-01

    Full Text Available A facile method was developed to synthesize in high yield dispersed silver nanoparticles (AgNPs with small particle sizes of less than 10 nm. Silver nitrate was reduced to silver nanoparticles by p-chloroaniline in the presence of polyoxyethylene maleate 4-nonyl-2-propylene-phenol (NMA as a stabilizer. The produced AgNPs were used to prepare hybrid polymer based on N-isopropylacrylamide (NIPAm, 2-acrylamido-2-methylpropane sulfonic acid (AMPS, N,N-methylenebisacrylamide (MBA and potassium persulfate (KPS using a semi-batch solution polymerization method. The prepared AgNPs and hybrid polymer were characterized by Fourier transform infrared (FTIR spectroscopy, X-ray diffraction (XRD patterns and transmission electron microscopy (TEM. The corrosion inhibition activity of the AgNPs and hybrid polymer towards steel corrosion in the presence of hydrochloric acid has been investigated by polarization and electrochemical impedance spectroscopy (EIS methods. Polarization measurements indicate that the AgNPs and hybrid polymer acts as a mixed type-inhibitor and the inhibition efficiency increases with inhibitor concentration. The results of potentiodynamic polarization and EIS measurements clearly showed that the inhibition mechanism involves blocking of the steel surface by inhibitor molecules via adsorption.

  14. 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.

  15. 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.

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

    International Nuclear Information System (INIS)

    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

  17. Self-consistent scheme for optical response of large hybrid networks of semiconductor quantum dots and plasmonic metal nanoparticles

    Science.gov (United States)

    Hayati, L.; Lane, C.; Barbiellini, B.; Bansil, A.; Mosallaei, H.

    2016-06-01

    We discuss a self-consistent scheme for treating the optical response of large, hybrid networks of semiconducting quantum dots (SQDs) and plasmonic metallic nanoparticles (MNPs). Our method is efficient and scalable and becomes exact in the limiting case of weakly interacting SQDs. The self-consistent equations obtained for the steady state are analogous to the von Neumann equations of motion for the density matrix of a SQD placed in an effective electric field computed within the discrete dipole approximation. Illustrative applications of the theory to square and honeycomb SQD, MNP, and hybrid SDQ-MNP lattices as well as SQD-MNP dimers are presented. Our results demonstrate that hybrid SQD-MNP lattices can provide flexible platforms for light manipulation with tunable resonant characteristics.

  18. 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.

  19. 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.

  20. Biosynthesis of bacterial cellulose in the presence of different nanoparticles to create novel hybrid materials.

    Science.gov (United States)

    Erbas Kiziltas, Esra; Kiziltas, Alper; Blumentritt, Melanie; Gardner, Douglas J

    2015-09-20

    The unique micro-nano porous three-dimensional network of bacterial cellulose (BC) can facilitate the incorporation of nanoparticles (NPs) into the BC matrix to create advanced BC-based functional nanomaterials for diverse applications. In this study, novel nanomaterials comprised of bacterial cellulose (BC) synthesized in the presence of different NPs (cellulose nanofibrils (CNF), exfoliated graphite nanoplatelets (xGnP), and nanoclay (NC)) were prepared using an in situ approach. NPs at 0.5 wt.% loading were added into the BC culture medium and their effect on the resulting nanocomposite structure was studied by field emission scanning electron microscopy (FE-SEM), X-Ray diffraction (XRD), Fourier transform infrared spectroscopy (FT-IR), and thermogravimetric analysis (TGA). All BC-based nanomaterials produced, exhibited good dispersion of the NPs within the BC matrix and the NPs were found embedded among the voids and microfibrils. The thermal stability and residual mass of BC-xGnP and BC-NC nanomaterials was significantly increased compared with the neat BC. CNF incorporation into the BC matrix did not change the thermal stability and residual mass of the BC matrix. This study also provides novel insights into the properties of the hybrid materials, and shows the approach used to make these materials which results in increased performance for chosen applications. PMID:26050900

  1. 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.

  2. Polyaniline nanoparticle-carbon nanotube hybrid network vapour sensors with switchable chemo-electrical polarity

    International Nuclear Information System (INIS)

    Chemo-resistive sensors were prepared from monodisperse poly(aniline) nanoparticles (PaniNP) synthesized via oxidative dispersion polymerization. Poly(styrene sulfonic acid) (PSSA) was used as the stabilizer and dopant agent. PaniNP transducers were assembled by spraying layer by layer a solution containing different concentrations of PaniNP and multi-wall carbon nanotubes (MWNT) onto interdigitated electrodes. This process led to stable sensors with reproducible responses upon chemical cycling. Chemo-electrical properties of these sensors have been investigated in sequential flows of pure nitrogen and nitrogen saturated with a set of volatile organic compounds (VOC). Interestingly the sensing mode of PaniNP transducers (the NVC or PVC effect) can be switched simply by increasing PaniNP content or by the addition of only 0.5% of MWNT to reach a resistance lower than 150 Ω. Due to their original conducting architecture well imaged by atomic force microscopy (AFM), i.e. a double percolated conductive network, PaniNP-MWNT hybrids present both higher sensitivity and selectivity than other formulations, demonstrating a positive synergy. Mechanisms are proposed to describe the original chemo-electrical behaviours of PaniNP-based sensors and explain the origin of their selectivity and sensing principle. These features make them attractive to be integrated in e-noses.

  3. 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.

  4. 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

  5. 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

  6. 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

  7. 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.

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

    International Nuclear Information System (INIS)

    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 μM of cysteine in pH 4.0 buffer solutions, and a linear calibration plot with a slope of 0.115 μA/μM is obtained. The detection limit (S/N = 3) is 0.05 μM. Additionally, the proposed methods obtain satisfactory results in the detection of cysteine-containing medicine samples.

  9. 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.

  10. 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.

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

    Science.gov (United States)

    Farkas, Balazs; Rodio, Marina; Romano, Ilaria; Diaspro, Alberto; Intartaglia, Romuald; Beke, Szabolcs

    2015-01-01

    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. PMID:26734513

  12. 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.

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

    International Nuclear Information System (INIS)

    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

  14. Facile Fabrication of Binder-free Metallic Tin Nanoparticle/Carbon Nanofiber Hybrid Electrodes for Lithium-ion Batteries

    International Nuclear Information System (INIS)

    In this work, a Sn nanoparticle (NP)/carbon nanofiber (CNF) hybrid with unique structure has been designed and fabricated via electrospinning and subsequent heat treatment. The cell assembled by the binder-free Sn NP/CNF hybrid demonstrates an effective capacity (46 mAh g−1 at 200 mA g−1 after 200 cycles) with high coulombic efficiency (up to 99.8%), suggesting a facile strategy for the scalable fabrication of electrochemically stable electrodes for LIBs. For understanding the electrochemical behaviors of the metallic Sn and carbon nanofibers in the lithiation/delithiation process, in situ transmission electron microscopy was applied to study the single hybrid structure. In the first charge/discharge process, real-time size variation of the Sn NP and CNFs was mainly focused, suggesting a two-step lithiation process in the metallic Sn NP. Structural characterization also indicates an irreversible delithiation in a single Sn NP/CNF hybrid structure. The electrochemical performance based on influence of carbonization temperature has also been discussed. The results and fundamental understanding of the lithiation/delithiation in the Sn-based hybrid anodes enables the communities to design flexible high-performance electrodes based on metallic active materials in a rational way

  15. 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.

  16. Controlled preparation of carbon nanotube-iron oxide nanoparticle hybrid materials by a modified wet impregnation method

    Energy Technology Data Exchange (ETDEWEB)

    Tsoufis, Theodoros, E-mail: ttsoufis@cc.uoi.gr [University of Ioannina, Department of Materials Science and Engineering (Greece); Douvalis, Alexios P. [University of Ioannina, Physics Department (Greece); Lekka, Christina E. [University of Ioannina, Department of Materials Science and Engineering (Greece); Trikalitis, Pantelis N. [University of Crete, Department of Chemistry (Greece); Bakas, Thomas [University of Ioannina, Physics Department (Greece); Gournis, Dimitrios [University of Ioannina, Department of Materials Science and Engineering (Greece)

    2013-09-15

    We report a novel, simple, versatile, and reproducible approach for the in situ synthesis of iron oxide nanoparticles (NP) on the surface of carbon nanotubes (CNT). Chemically functionalized single- or multi-wall CNT were used as nanotemplates for the synthesis of a range of very small (<10 nm) ferrimagnetic and/or anti-ferromagnetic iron oxide NP on their surface. For the synthesis of the hybrid materials, we employed for the first time a modified wet impregnation method involving the adsorption of ferric cations (as nanoparticle's precursor) on the functionalized nanotube surface and the subsequent interaction with acetic acid vapors followed by calcination at 400 Degree-Sign C under different atmospheres (air, argon, and oxygen). X-ray diffraction, transmission electron microscopy, Moessbauer spectroscopy, and magnetization measurements were used to study in-detail the morphology, size, and type of crystalline phases in the resulting hybrid materials. In addition, Raman measurements were used to monitor possible structural changes of the nanotubes during the synthetic approach. The experimental results were further supported by density functional theory calculations. These calculations were also used to disclose, how the type of the carbon nanotube template affects the nature and the size of the resulting NP in the final hybrids.

  17. 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.

  18. 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

  19. Synthesis, Characterization, and Functionalization of Hybrid Au/CdS and Au/ZnS Core/Shell Nanoparticles.

    Science.gov (United States)

    Tobias, Andrew; Qing, Song; Jones, Marcus

    2016-01-01

    Plasmonic nanoparticles are an attractive material for light harvesting applications due to their easily modified surface, high surface area and large extinction coefficients which can be tuned across the visible spectrum. Research into the plasmonic enhancement of optical transitions has become popular, due to the possibility of altering and in some cases improving photo-absorption or emission properties of nearby chromophores such as molecular dyes or quantum dots. The electric field of the plasmon can couple with the excitation dipole of a chromophore, perturbing the electronic states involved in the transition and leading to increased absorption and emission rates. These enhancements can also be negated at close distances by energy transfer mechanism, making the spatial arrangement of the two species critical. Ultimately, enhancement of light harvesting efficiency in plasmonic solar cells could lead to thinner and, therefore, lower cost devices. The development of hybrid core/shell particles could offer a solution to this issue. The addition of a dielectric spacer between a gold nanoparticles and a chromophore is the proposed method to control the exciton plasmon coupling strength and thereby balance losses with the plasmonic gains. A detailed procedure for the coating of gold nanoparticles with CdS and ZnS semiconductor shells is presented. The nanoparticles show high uniformity with size control in both the core gold particles and shell species allowing for a more accurate investigation into the plasmonic enhancement of external chromophores. PMID:26967555

  20. Iodinated silica/porphyrin hybrid nanoparticles for X-ray computed tomography/fluorescence dual-modal imaging of tumors

    Directory of Open Access Journals (Sweden)

    Koichiro Hayashi

    2014-12-01

    Full Text Available Silica nanoparticles containing covalently linked iodine and a near-infrared (NIR fluorescence dye, namely porphyrin, have been synthesized through a one-pot sol–gel reaction. These particles are called iodinated silica/porphyrin hybrid nanoparticles (ISP HNPs. The ISP HNPs have both high X-ray absorption coefficient and NIR fluorescence. The ISP HNPs modified with folic acid (FA and polyethylene glycol (PEG, denoted as FA-PEG-ISP HNPs, enabled the successful visualization of tumors in mice by both X-ray computed tomography (CT and fluorescence imaging (FI. Thus, the FA-PEG-ISP HNPs are useful as contrast agents or probes for CT/FI dual-modal imaging.

  1. 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.

  2. 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.

  3. DNA hybridization activity of single-stranded DNA-conjugated gold nanoparticles used as probes for DNA detection

    Science.gov (United States)

    Kira, Atsushi; Matsuo, Kosuke; Nakajima, Shin-ichiro

    2016-02-01

    Colloidal nanoparticles (NPs) have potential applications in bio-sensing technologies as labels or signal enhancers. In order to meet demands for a development of biomolecular assays by a quantitative understanding of single-molecule, it is necessary to regulate accuracy of the NPs probes modified with biomolecules to optimize the characteristics of NPs. However, to our knowledge, there is little information about the structural effect of conjugated biomolecules to the NPs. In this study, we investigated the contribution of a density of single-stranded DNA (ssDNA) conjugating gold NP to hybridization activity. Hybridization activity decreased in accordance with increases in the density of attached ssDNAs, likely due to electrostatic repulsion generated by negatively charged phosphate groups in the ssDNA backbone. These results highlight the importance of controlling the density of ssDNAs attached to the surface of NPs used as DNA detection probes.

  4. Direct Observation of Photoinduced Charge Separation in Ruthenium Complex/Ni(OH)2 nanoparticle Hybrid

    Energy Technology Data Exchange (ETDEWEB)

    Tang, Yu; Pattengale, Brian A.; Ludwig, John M.; Atifi, Abderrahman; Zinovev, Alexander V.; Dong, Bin; Kong, Qingyu; Zuo, Xiaobing; Zhang, Xiaoyi; Huang, Jier

    2015-12-17

    Ni(OH)2 have emerged as important functional materials for solar fuel conversion because of their potential as cost-effective bifunctional catalysts for both hydrogen and oxygen evolution reactions. However, their roles as photocatalysts in the photoinduced charge separation (CS) reactions remain unexplored. In this paper, we investigate the CS dynamics of a newly designed hybrid catalyst by integrating a Ru complex with Ni(OH)2 nanoparticles (NPs). Using time resolved X-ray absorption spectroscopy (XTA), we directly observed the formation of the reduced Ni metal site (~60 ps), unambiguously demonstrating CS process in the hybrid through ultrafast electron transfer from Ru complex to Ni(OH)2 NPs. Compared to the ultrafast CS process, the charge recombination in the hybrid is ultraslow (>>50 ns). These results not only suggest the possibility of developing Ni(OH)2 as solar fuel catalysts, but also represent the first time direct observation of efficient CS in a hybrid catalyst using XTA.

  5. Hybrid nanostructured solar cells based on the incorporation of inorganic nanoparticles in polymer-fullerene mixtures

    Science.gov (United States)

    de Freitas, Jilian N.; Nogueira, Ana Flávia

    2010-08-01

    Ternary systems based on mixtures of polymer, PCBM and CdSe nanoparticles were investigated. The photophysical and electrochemical properties were modulated by changing the size of the inorganic nanoparticles and their effects on the performance of the solar cells were analyzed. At the optimized conditions, the presence of the nanoparticles increased the photocurrent and photovoltage, improving the efficiency of the devices. A complete study on the morphologic effects induced by the presence of these nanoparticles was performed using AFM, HR-TEM and optical microscopy techniques.

  6. 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.

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

    International Nuclear Information System (INIS)

    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.

  8. 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

  9. 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

  10. Visual discrimination of dihydroxybenzene isomers based on a nitrogen-doped graphene quantum dot-silver nanoparticle hybrid

    Science.gov (United States)

    Shi, Bingfang; Su, Yubin; Zhao, Jingjin; Liu, Rongjun; Zhao, Yan; Zhao, Shulin

    2015-10-01

    A room temperature reducing agent-free strategy for the synthesis of a nitrogen-doped graphene quantum dot-silver nanoparticle (N-GQD/AgNP) hybrid was presented. In this strategy, N-GQDs were used as a reducing agent and stabilizer for the formation of the N-GQD/AgNP hybrid, and the formation of the N-GQD/AgNP hybrid may result from the extraordinary reduction properties of N-GQDs, which are attributed to the nature of the surface oxygen-containing functional groups. The N-GQD/AgNP hybrid exhibits good dispersity and outstanding catalytic ability toward the oxidation of catechol (CC) and hydroquinone (HQ) by Ag+. In the presence of the N-GQD/AgNP hybrid, the reduction of Ag+ by CC and HQ was improved. CC enhanced the absorbance of the N-GQD/AgNP-Ag+ system the most, and HQ followed, while resorcinol (RC) had only a little effect on the absorption intensity of the system. Thus, a sensitive and selective colorimetric sensing method based on the N-GQD/AgNP-Ag+ system was developed for the discrimination of CC, HQ and RC. A good linear relationship was obtained from 0.1 to 15.0 μM for CC and from 0.3 to 20.0 μM for HQ. The detection limits of CC and HQ were 0.03 and 0.1 μM, respectively. In addition, the proposed method also shows a high selectivity for the detection of CC and HQ, and appreciable changes in color of the N-GQD/AgNP-Ag+ system toward CC, RC and HQ were observed.A room temperature reducing agent-free strategy for the synthesis of a nitrogen-doped graphene quantum dot-silver nanoparticle (N-GQD/AgNP) hybrid was presented. In this strategy, N-GQDs were used as a reducing agent and stabilizer for the formation of the N-GQD/AgNP hybrid, and the formation of the N-GQD/AgNP hybrid may result from the extraordinary reduction properties of N-GQDs, which are attributed to the nature of the surface oxygen-containing functional groups. The N-GQD/AgNP hybrid exhibits good dispersity and outstanding catalytic ability toward the oxidation of catechol (CC) and

  11. 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.

  12. 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.

  13. 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

  14. 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.

  15. 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.

  16. 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)

  17. Supramolecular hybrid of gold nanoparticles and semiconducting single-walled carbon nanotubes wrapped by a porphyrin-fluorene copolymer.

    Science.gov (United States)

    Ozawa, Hiroaki; Yi, Xun; Fujigaya, Tsuyohiko; Niidome, Yasuro; Asano, Tanemasa; Nakashima, Naotoshi

    2011-09-21

    We describe the design, synthesis, and characterization of a supramolecular hybrid of gold nanometals and semiconducting single-walled carbon nanotubes (SWNTs) wrapped by a porphyrin-fluorene copolymer (1), as well as fabrication of a thin-film transistor (TFT) device using the hybrid. Photoluminescence mapping revealed that the copolymer selectively dissolved SWNTs with chirality indices of (8,6), (8,7), (9,7), (7,6), and (7,5); dissolution of (8,6), and (8,7) SWNTs was especially efficient. The solubilized SWNTs were connected to gold nanoparticles (AuNPs) via a coordination bond to prepare a supramolecular hybrid composed of AuNPs/copolymer 1-wrapped SWNTs, which were studied by atomic force and scanning and transmission electron microscopies. A fabricated TFT device using the semiconducting SWNTs/copolymer 1 shows evident p-type transport with an On/Off ratio of ~10(5). The transport properties of the TFT changed after coordination of the AuNPs with the SWNTs/copolymer 1. PMID:21827201

  18. Facile Synthesis of Au or Ag Nanoparticles-Embedded Hollow Carbon Microspheres from Metal-Organic Framework Hybrids and Their Efficient Catalytic Activities.

    Science.gov (United States)

    Choi, Sora; Lee, Hee Jung; Oh, Moonhyun

    2016-05-01

    Au or Ag nanoparticles-embedded hollow carbon spheres, which display outstanding catalytic activity and excellent recyclability, are prepared by a one-step pyrolysis of metal-organic framework (MOF) hybrids consisting of polystyrene cores and MOF shells loaded with noble metal ions (polystyrene@ZIF-8/M(n+) ; M(n+) = Au(3+) or Ag(+) ). PMID:27151828

  19. 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)

  20. Novel theranostics based on hybrid nanoparticles for early cancer detection and treatment

    OpenAIRE

    Li, Siyue; 李思越

    2013-01-01

    Nanoscience and nanotechnology have advanced rapidly in recent years and have made a profound impact in the medical field. Nanoparticles have attracted great attention for their potential as diagnostic and/or therapeutic tools in oncology owing to their unique properties. Theranostics are nanodevices with diagnostic, therapeutic and possibly treatment-monitoring functions for treating cancers. Different noble metal nanoparticles can provide the basic unit for theranostics. Suitably designed a...

  1. 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.

  2. 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.

  3. 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.

  4. Anisotropic silver nanoparticles as filler for the formation of hybrid nanocomposites

    International Nuclear Information System (INIS)

    Graphical abstract: Display Omitted Highlights: ► Prismatic and plate-like Ag nanoparticles were used as a precursors for preparation Ag/poly(vinyl alcohol) nanocomposite films. ► Results showed that the degree of crystallinity of the polymer decreases with Ag nanoparticles content. ► The presence of Ag nanoparticles in PVA induces higher thermo-oxidative stability with respect to PVA. -- Abstract: Prismatic and plate-like silver nanoparticles (Ag NPs) were synthesized according to the seed-mediated method. These particles were used as precursors for preparation of homogenous, transparent and colored Ag/poly(vinyl alcohol) (PVA) nanocomposite films with different concentrations of Ag by solution-casting technique. Optical and structural characterization of these nanocomposites includes UV–visible spectroscopy, X-ray diffraction (XRD), FTIR spectroscopy and SEM measurements. Further, the effect of embedded nanoparticles on the thermal properties of the PVA matrix was studied. The value of the glass transition temperature of polymer is found to increase after embedding Ag NPs. Comparison of thermal properties of pure PVA and nanocomposite films showed that the thermo-oxidative stability of polymer slightly increased in the presence of Ag NPs. Furthermore, the effect of the Ag NPs on the crystallinity of polymer was also observed.

  5. 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.

  6. 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)

  7. 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.

  8. 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)

  9. Improving interfacial adhesion with epoxy matrix using hybridized carbon nanofibers containing calcium phosphate nanoparticles for bone repairing.

    Science.gov (United States)

    Gao, Xukang; Lan, Jinle; Jia, Xiaolong; Cai, Qing; Yang, Xiaoping

    2016-04-01

    Hybridized carbon nanofibers containing calcium phosphate nanoparticles (CNF/CaP) were investigated as osteocompatible nanofillers for epoxy resin. The CNF/CaP was produced by electrospinning mixture solution of polyacrylonitrile and CaP precursor sol-gel, followed by preoxidation and carbonization. The continuous and long CNF/CaP was ultrasonically chopped, mixed into epoxy resin and thermo-cured. Compared to pure CNFs with similar ultrasonication treatment, the shortened CNF/CaP reinforced composites demonstrated significant enhancement in flexural properties of epoxy composites, benefiting from the improved interfacial adhesion between CNF/CaP and resin matrix. The resulting composites also displayed good biocompatibility and sustained calcium ion release, which categorized them as promising materials for bone repairing. PMID:26838838

  10. 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.

  11. 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.

  12. Ligand Doping on the Hybrid Thermoelectric Materials Based on Terthiophene-Capped Silicon Nanoparticles

    Science.gov (United States)

    Ashby, Shane P.; Bian, Tiezheng; Guélou, Gabin; Powell, Anthony V.; Chao, Yimin

    2016-03-01

    Over the past 2 years, silicon nanoparticles (SiNPs) functionalised with conjugated molecules have been shown to have potential as low-temperature thermoelectric materials. One key challenge with such materials relates to the introduction of charge carriers. There are two components of organic/silicon nanocomposite materials in which charge carriers can be introduced: the silicon nanoparticle or the organic ligand. Investigation into the effect of introducing charge carriers on the ligands via oxidation is another step towards understanding and optimising this kind of system. Terthiophene-capped SiNPs have been synthesised and characterised before and after doping. Using different ratios and the oxidant NOBF4 to dope the surface ligands, the electrical conductivity has been measured at ambient temperature. The ratio of oxidant to nanoparticles shows similar trends in electrical resistivity to that of conventional conductive polymers and shows significant improvements over the undoped material.

  13. Magnetic behavior of iron (III) oxyhydroxy nanoparticles in organic-inorganic hybrid matrices

    International Nuclear Information System (INIS)

    Magnetic properties of iron(III) oxyhydroxy nanoparticles stabilized within a sol-gel derived organic-inorganic matrix are investigated. Depending on the size of the polymer chain and on the sol-gel route, ferrihydrite or Fe(III) oxyhydroxynitrate can be formed. Comparing different sets of samples we can address the observed magnetic features to the different oxyhydroxy phases. The ferrihydrite particles exhibit thermal and field irreversibility below 30 K, with coercive and exchange fields characteristic of antiferromagnetic nanoparticles uncompensated/canted spins. The existence of antiferromagnetic interactions in the Fe(III) oxyhydroxynitrate phase can be inferred

  14. 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...

  15. Hyaluronic Acid-Modified Cationic Lipid-PLGA Hybrid Nanoparticles as a Nanovaccine Induce Robust Humoral and Cellular Immune Responses.

    Science.gov (United States)

    Liu, Lanxia; Cao, Fengqiang; Liu, Xiaoxuan; Wang, Hai; Zhang, Chao; Sun, Hongfan; Wang, Chun; Leng, Xigang; Song, Cunxian; Kong, Deling; Ma, Guilei

    2016-05-18

    Here, we investigated the use of hyaluronic acid (HA)-decorated cationic lipid-poly(lactide-co-glycolide) acid (PLGA) hybrid nanoparticles (HA-DOTAP-PLGA NPs) as vaccine delivery vehicles, which were originally developed for the cytosolic delivery of genes. Our results demonstrated that after the NPs uptake by dendritic cells (DCs), some of the antigens that were encapsulated in HA-DOTAP-PLGA NPs escaped to the cytosolic compartment, and whereas some of the antigens remained in the endosomal/lysosomal compartment, where both MHC-I and MHC-II antigen presentation occurred. Moreover, HA-DOTAP-PLGA NPs led to the up-regulation of MHC, costimulatory molecules, and cytokines. In vivo experiments further revealed that more powerful immune responses were induced from mice immunized with HA-DOTAP-PLGA NPs when compared with cationic lipid-PLGA nanoparticles and free ovalbumin (OVA); the responses included antigen-specific CD4(+) and CD8(+) T-cell responses, the production of antigen-specific IgG antibodies and the generation of memory CD4(+) and CD8(+) T cells. Overall, these data demonstrate the high potential of HA-DOTAP-PLGA NPs for use as vaccine delivery vehicles to elevate cellular and humoral immune responses. PMID:27088457

  16. 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.

  17. 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

  18. A hybrid approach for the simulation of a nearly neutrally buoyant nanoparticle thermal motion in an incompressible Newtonian fluid medium.

    Science.gov (United States)

    Uma, B; Radhakrishnan, R; Eckmann, D M; Ayyaswamy, P S

    2013-01-01

    A hybrid scheme based on Markovian fluctuating hydrodynamics of the fluid and a non-Markovian Langevin dynamics with the Ornstein-Uhlenbeck noise perturbing the translational and rotational equations of motion of a nanoparticle is employed to study the thermal motion of a nearly neutrally buoyant nanoparticle in an incompressible Newtonian fluid medium. A direct numerical simulation adopting an arbitrary Lagrangian-Eulerian based finite element method is employed in simulating the thermal motion of the particle suspended in the fluid contained in a cylindrical vessel. The instantaneous flow around the particle and the particle motion are fully resolved. The numerical results show that (a) the calculated temperature of the nearly neutrally buoyant Brownian particle in a quiescent fluid satisfies the equipartition theorem; (b) the translational and rotational decay of the velocity autocorrelation functions result in algebraic tails, over long time; (c) the translational and rotational mean square displacements of the particle obeys Stokes-Einstein and Stokes-Einstein-Debye relations, respectively; and (d) the parallel and perpendicular diffusivities of the particle closer to the wall are consistent with the analytical results, where available. The study has important implications for designing nanocarriers for targeted drug delivery. PMID:23814315

  19. 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.

  20. 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.

  1. Multifunctional Fe3O4@C@Ag hybrid nanoparticles: Aqueous solution preparation, characterization and photocatalytic activity

    International Nuclear Information System (INIS)

    Highlights: ► Ag-loaded Fe3O4@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 Fe3O4@C nanocomposites show superior magnetism and photocatalytic activity. ► A simple synthetic process was discussed. - Abstract: The paper describes a kind of multifunctional Fe3O4@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 Fe3O4 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

  2. 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.

  3. h-BN Nanosheets as 2D Substrates to Load 0D Fe3 O4 Nanoparticles: A Hybrid Anode Material for Lithium-Ion Batteries.

    Science.gov (United States)

    Duan, Zhi-Qiang; Liu, Yi-Tao; Xie, Xu-Ming; Ye, Xiong-Ying; Zhu, Xiao-Dong

    2016-03-18

    h-BN, as an isoelectronic analogue of graphene, has improved thermal mechanical properties. Moreover, the liquid-phase production of h-BN is greener since harmful oxidants/reductants are unnecessary. Here we report a novel hybrid architecture by employing h-BN nanosheets as 2D substrates to load 0D Fe3 O4 nanoparticles, followed by phenol/formol carbonization to form a carbon coating. The resulting carbon-encapsulated h-BN@Fe3 O4 hybrid architecture exhibits synergistic interactions: 1) The h-BN nanosheets act as flexible 2D substrates to accommodate the volume change of the Fe3 O4 nanoparticles; 2) The Fe3 O4 nanoparticles serve as active materials to contribute to a high specific capacity; and 3) The carbon coating not only protects the hybrid architecture from deformation but also keeps the whole electrode highly conductive. The synergistic interactions translate into significantly enhanced electrochemical performances, laying a basis for the development of superior hybrid anode materials. PMID:26833884

  4. Sporocidic properties of poly(vinyl alcohol)/silver nanoparticles/TEOS thin hybrid films.

    Science.gov (United States)

    Pencheva, Daniela; Bryaskova, Rayna; Lad, Umesh; Kale, Girish M; Kantardjiev, T

    2012-06-01

    The sporocidic activity of hybrid materials based on PVA/AgNps/TEOS thin films has been investigated. Deep Agar Method has been applied to study the sporocidic properties of these hybrid materials with different silver concentrations. This method has been used because of the lack of standard methods for testing the sporocidic activity in such materials and due to the specific characteristics of bacterial spore. Clear and pronounced presence of sporocidic activity of the hybrid materials towards spores of control strains Bacillus subtilis ATCC 6633 and Geobacillus stearothermophilus ATCC 7953 has been established. The use of chromatographic paper disks impregnated with PVA/AgNps/TEOS showed the advantages in testing the biological properties of the hybrid material in comparison to the disks obtained by directly cutting the PVA/AgNps/TEOS films. The highest sporocidic activity, although with small deviation of 0.5-1.0 mm, was established at the PVA/AgNps/TEOS hybrid films with concentration of silver precursor 9.2 mg/mL and 18.3 mg/mL. The experiments were performed with the aim to reveal the opportunities for a practical application of the material. PMID:22764416

  5. 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 ...

  6. 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

  7. 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.

  8. Compartmentalization in hybrid metallacarborane nanoparticles formed by block copolymers with star-like architecture

    Czech Academy of Sciences Publication Activity Database

    Ďorďovič, V.; Uchman, M.; Zhigunov, Alexander; Nykänen, A.; Ruokolainen, J.; Matějíček, P.

    2014-01-01

    Roč. 3, č. 11 (2014), s. 1151-1155. ISSN 2161-1653 R&D Projects: GA ČR(CZ) GA14-14608S Institutional support: RVO:61389013 Keywords : nanoparticles * block copolymers * star-like architecture Subject RIV: CD - Macromolecular Chemistry Impact factor: 5.764, year: 2014

  9. 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.

  10. Surface and related bulk properties of titania nanoparticles recovered from aramid–titania hybrid films: A novel attempt

    International Nuclear Information System (INIS)

    Highlights: ► Aramid–titania hybrid films (5 and 10 wt%-TiO2) were prepared via sol–gel processing. ► 450 °C calcination of the films yield anatase-TiO2 nanoparticles of rod-like morphology. ► The titania nanoparticle, crystal structure, high surface area are stable up to 800 °C. ► The novel approach has the advantage of nearly 100% recovery of titania. ► Increasing calcination temperature up to 1100 °C triggers anatase → rutile transition. -- Abstract: 5 and 10 wt%-TiO2-containing aramid–titania hybrid films were prepared using sol–gel processing improved by the inclusion of 3-isocyanato-propyltriethoxysilane (ICTOS) to strengthen bonding of the titania species to the polymer backbone and, hence, lessen its agglomeration. The films were thermally degraded by heating at 450 °C in a dynamic atmosphere of air. The solid residues were found by thermogravimetry, X-ray diffractometry and electron microscopy to consist dominantly of uniformly agglomerated rod-like anatase-TiO2 nanoparticles, irrespective of the titania content of the film. The recovered titania particle morphology and surface microstructure were examined by field emission scanning and high-resolution transmission electron microscopy, respectively. Whereas, the particle surface chemistry and texture were assessed, respectively, by means of X-ray photoelectron spectroscopy and N2 sorptiometry. The recovered titanias were found, irrespective of the film content of titania, to enjoy not only a high temperature (up to 800 °C) stable nanoscopic anatase bulk structure, but also a high-temperature stable surface chemical composition (lattice Ti4+ and O2−, and adsorbed OH/CHx species), (101)-faceted microstructure and highly accessible (145–112 m2/g), uniform mesoporous texture with average pore diameter in the narrow range of 3.9–6.3 nm. Increasing the calcination temperature up to 1100 °C enhances an anatase → rutile transition, the extent of which is larger the higher the

  11. Thickness Dependent Nanostructural, Morphological, Optical and Impedometric Analyses of Zinc Oxide-Gold Hybrids: Nanoparticle to Thin Film.

    Science.gov (United States)

    Perumal, Veeradasan; Hashim, Uda; Gopinath, Subash C B; Haarindraprasad, R; Liu, Wei-Wen; Poopalan, P; Balakrishnan, S R; Thivina, V; Ruslinda, A R

    2015-01-01

    The creation of an appropriate thin film is important for the development of novel sensing surfaces, which will ultimately enhance the properties and output of high-performance sensors. In this study, we have fabricated and characterized zinc oxide (ZnO) thin films on silicon substrates, which were hybridized with gold nanoparticles (AuNPs) to obtain ZnO-Aux (x = 10, 20, 30, 40 and 50 nm) hybrid structures with different thicknesses. Nanoscale imaging by field emission scanning electron microscopy revealed increasing film uniformity and coverage with the Au deposition thickness. Transmission electron microscopy analysis indicated that the AuNPs exhibit an increasing average diameter (5-10 nm). The face center cubic Au were found to co-exist with wurtzite ZnO nanostructure. Atomic force microscopy observations revealed that as the Au content increased, the overall crystallite size increased, which was supported by X-ray diffraction measurements. The structural characterizations indicated that the Au on the ZnO crystal lattice exists without any impurities in a preferred orientation (002). When the ZnO thickness increased from 10 to 40 nm, transmittance and an optical bandgap value decreased. Interestingly, with 50 nm thickness, the band gap value was increased, which might be due to the Burstein-Moss effect. Photoluminescence studies revealed that the overall structural defect (green emission) improved significantly as the Au deposition increased. The impedance measurements shows a decreasing value of impedance arc with increasing Au thicknesses (0 to 40 nm). In contrast, the 50 nm AuNP impedance arc shows an increased value compared to lower sputtering thicknesses, which indicated the presence of larger sized AuNPs that form a continuous film, and its ohmic characteristics changed to rectifying characteristics. This improved hybrid thin film (ZnO/Au) is suitable for a wide range of sensing applications. PMID:26694656

  12. 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...

  13. 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

  14. 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.

  15. 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 ...

  16. 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.

  17. 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

  18. 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.

  19. 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

  20. 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

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

    International Nuclear Information System (INIS)

    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 CeO2 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

  2. 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.

  3. 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

  4. 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.

  5. 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

  6. Hybrid organic-inorganic coatings and films containing conducting polyaniline nanoparticles

    Czech Academy of Sciences Publication Activity Database

    Špírková, Milena; Stejskal, Jaroslav; Prokeš, J.

    2004-01-01

    Roč. 212, č. 1 (2004), s. 343-348. ISSN 1022-1360. [Electrical and Related Properties of Polymers and Other Organic Solids /9./. Prague, 14.07.2002-18.07.2002] R&D Projects: GA AV ČR KSK4050111; GA ČR GA203/01/0735 Institutional research plan: CEZ:AV0Z4050913 Keywords : atomic force microscopy * films * hybrid networks Subject RIV: CD - Macromolecular Chemistry Impact factor: 0.691, year: 2004

  7. 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...

  8. 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.

  9. Hybrid photoelectrode by using vertically aligned rutile TiO2 nanowires inlaid with anatase TiO2 nanoparticles for dye-sensitized solar cells

    International Nuclear Information System (INIS)

    We report a hybrid photoelectrode fabricated by using single crystalline rutile TiO2 nanowires (NWs) inlaid with anatase TiO2 nanoparticles (NPs) for efficient dye-sensitized solar cells. For this purpose, ∼4-μm-thick vertically aligned NWs were synthesized on the FTO glass substrate through a solvothermal treatment. Then, as-prepared NW film was treated with the NP colloidal dispersion to construct the NW–NP film. In particular, the NWs offer a fast pathway for electron transport as well as light scattering effect. On the other hand, the inlaid NPs give an extra amount of space for the dye-uptake. Accordingly, the present NW–NP electrode exhibited 6.2% of the conversion efficiency, which corresponds to ∼48% improvement over the efficiency of the NP-DSC. We attribute this notable result to the synergetic effects of the enhanced light confinement, charge collection, and dye-loading. - Highlights: • The hybrid system was designed by combining TiO2 nanowires with TiO2 nanoparticles. • Vertically aligned nanowires show rapid charge transfer and light scattering effects. • The inlaid nanoparticles provide an additional surface area for dye loading. • The hybrid structure exhibits a noticeable enhancement in the conversion efficiency

  10. 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

  11. 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

  12. Chitosan-pectin hybrid nanoparticles prepared by coating and blending techniques.

    Science.gov (United States)

    Rampino, A; Borgogna, M; Bellich, B; Blasi, P; Virgilio, F; Cesàro, A

    2016-03-10

    The preparation of chitosan nanoparticles in combination with pectins, as additional mucoadhesive biopolymers, was investigated. Pectins from apple and from citrus fruit were considered; polygalacturonic acid was taken as a reference. Tripolyphosphate was used as an anionic cross-linker. Two different techniques were compared, namely the coating and the blending. Coated nanoparticles (NPs) in the ratio pectin:NPs from 2:1 to 5:1 evidenced that the size of NPs increased as the amount of pectin (both from apple and citrus fruit) was increased. In particular, for NPs coated with pectin from citrus fruit the size ranges from 200 to 260nm; while for NPs coated with pectin from apple the size ranges from 330 to 450nm. A minimum value of Z-potential around -35mV was obtained for the ratio pectin:NPs 4:1, while further addition of pectin did not decrease the Z-potential. Also blended NPs showed a dependence of the size on the ratio of the components: for a given ratio pectin:tripolyphosphate the size increases as the fraction of chitosan increases; for a low ratio chitosan:pectin a high amount of tripolyphosphate was needed to obtain a compact structure. The effect of the additional presence of loaded proteins in chitosan-pectin nanoparticles was also investigated, since proteins contribute to alter the electrostatic interactions among charged species. FT-IR and DSC characterization are presented to confirm the interactions between biopolymers. Finally, the biocompatibility of the used materials was assessed by the chorioallantoic membrane assay, confirming the safety of the materials. PMID:26772898

  13. Electrical and optical properties of hybrid polymer solar cells incorporating Au and CuO nanoparticles

    OpenAIRE

    Aruna P. Wanninayake; Shengyi Li; Benjamin C. Church; Nidal Abu-Zahra

    2015-01-01

    In this study, to enhance the power conversion efficiency (PCE) of the polymer solar cells (PSCs), Gold (Au) and Copper oxide nanoparticles (CuO-NPs) are incorporated into the PEDOT:PSS and P3HT/PCBM active layers respectively. PSCs with a constant CuO-NP content were fabricated with varying amounts of Au NPs. Addition of Au NPs increased the power conversion efficiency by up to 18% compared to a reference cell without Au-NPs. The short circuit current(Jsc) of the cells containing 0.06 mg of ...

  14. 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

  15. Electrical and optical properties of hybrid polymer solar cells incorporating Au and CuO nanoparticles

    Directory of Open Access Journals (Sweden)

    Aruna P. Wanninayake

    2015-12-01

    Full Text Available In this study, to enhance the power conversion efficiency (PCE of the polymer solar cells (PSCs, Gold (Au and Copper oxide nanoparticles (CuO-NPs are incorporated into the PEDOT:PSS and P3HT/PCBM active layers respectively. PSCs with a constant CuO-NP content were fabricated with varying amounts of Au NPs. Addition of Au NPs increased the power conversion efficiency by up to 18% compared to a reference cell without Au-NPs. The short circuit current(Jsc of the cells containing 0.06 mg of Au NPs was measured at 7.491 mA/cm2 compared to 6.484 mA/cm2 in the reference cells with 0.6 mg of CuO nanoparticles; meanwhile, the external quantum efficiency(EQE increased from 53% to 61%, showing an enhancement of 15.1%. Au-NPs improved the charge collection at the anode, which results in higher short circuit current and fill factor. However, the strong near field surrounding Au-NPs due to localized surface plasmonic resonance (LSPR effect is not distributed into the active layer. Instead, it is spread horizontally through the PEDOT:PSS layer, thus minimizing the light absorption in the active layer.

  16. 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

  17. 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.

  18. 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.

  19. 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...

  20. 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

  1. 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.

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

    Energy Technology Data Exchange (ETDEWEB)

    Tiwari, Ida, E-mail: sensorsbhu@yahoo.co.in; Gupta, Mandakini

    2014-01-01

    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{sup −7} at signal to noise ratio 3.

  3. A facile green approach to prepare core-shell hybrid PLGA nanoparticles for resveratrol delivery.

    Science.gov (United States)

    Kumar, Sandeep; Lather, Viney; Pandita, Deepti

    2016-03-01

    Green approach has revolutionized the area of nanoparticles (NPs) synthesis by virtue of eco and health friendly protocols. Advancing this further, the study proposes a captivating solvent free method for the preparation of green PLGA-oil nanohybrids (G-PONHs) using acrysol oil and encapsulation of resveratrol therein. G-PONHs were structurally similar to the standard PONHs, but had larger particle size of 375 nm. Avoidance of organic solvents resulted in the formation of smooth NPs which showed a considerable improvement in drug release profile and antioxidant properties. G-PONHs exhibited superior biocompatibility with normal Vero cells, while the cytotoxicity on breast cancer cells was moderate in comparison to standard NPs owing to their large size. The size of NPs was found to be a critical factor governing the amplitude of cytotoxicity. The comparative high stability of G-PONHs further favors the tremendous potential of this novel preparation method and delivery platform. PMID:26708438

  4. 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.

  5. 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

  6. 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

  7. Effect of acid or alkaline catalyst and of different capping agents on the optical properties of CdS nanoparticles incorporated within a diureasil hybrid matrix

    Science.gov (United States)

    Gonçalves, Luis F. F. F.; Silva, Carlos J. R.; Kanodarwala, Fehmida K.; Stride, John A.; Pereira, Mario R.

    2015-11-01

    CdS nanoparticles (NPs) were synthesized using colloidal methods and incorporated within a diureasil hybrid matrix. The surface capping of the CdS NPs by 3-mercaptopropyltrimethoxysilane (MPTMS) and 3-aminopropyltrimethoxysilane (APTMS) organic ligands during the incorporation of the NPs within the hybrid matrix has been investigated. The matrix is based on poly(ethylene oxide)/poly(propylene oxide) chains grafted to a siliceous skeleton through urea bonds and was produced by sol-gel process. Both alkaline and acidic catalysis of the sol-gel reaction were used to evaluate the effect of each organic ligand on the optical properties of the CdS NPs. The hybrid materials were characterized by absorption, steady-state and time-resolved photoluminescence spectroscopy and High Resolution Transmission Electron Microscopy (HR-TEM). The preservation of the optical properties of the CdS NPs within the diureasil hybrids was dependent on the experimental conditions used. Both organic ligands (APTMS and MPTMS) demonstrated to be crucial in avoiding the increase of size distribution and clustering of the NPs within the hybrid matrix. The use of organic ligands was also shown to influence the level of interaction between the hybrid host and the CdS NPs. The CdS NPs showed large Stokes shifts and long average lifetimes, both in colloidal solution and in the xerogels, due to the origin of the PL emission in surface states. The CdS NPs capped with MPTMS have lower PL lifetimes compared to the other xerogel samples but still larger than the CdS NPs in the original colloidal solution. An increase in PL lifetimes of the NPs after their incorporation within the hybrid matrix is related to interaction between the NPs and the hybrid host matrix.

  8. 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

  9. 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.

  10. Solution-processed copper phthalocyanine–gold nanoparticle hybrid nanocomposite thin films

    International Nuclear Information System (INIS)

    Copper phthalocyanine (CuPc) thin film and gold nanoparticles (Au NPs) of size ∼ 20 nm were deposited on conducting indium tin oxide coated glass substrates. Thin films were ∼ 500 nm thick having crystalline nature determined by surface profilometer and X-ray diffraction technique. The concentration of Au NPs in the films was varied whereas the concentration of CuPc was constant. It was observed that surface morphology varied with Au NP concentration increase in the films accompanied by changes in the optical spectra over 300-1000 nm range and increase in the electrical conduction but no changes in the Fourier transform infra-red spectra. Such nanocomposite films would be useful in the fabrication of organic solar cells. - Highlights: • Optical and electrical properties of CuPc film are enhanced upon loading of Au NPs. • Upon loading of Au NPs in CuPc the surface morphology changes from sheets to fibers. • The systematic enhancement in current is observed by increasing Au NPs in CuPc film. • The XRD peak intensity of CuPc reduced with an increase in the concentration of Au NPs

  11. Hybrid optoacoustic and ultrasound biomicroscopy monitors’ laser-induced tissue modifications and magnetite nanoparticle impregnation

    International Nuclear Information System (INIS)

    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. (letter)

  12. 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

  13. 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.

  14. 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

  15. 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.

  16. Towards hybrid biocompatible magnetic rHuman serum albumin-based nanoparticles: use of ultra-small (CeLn)3/4+ cation-doped maghemite nanoparticles as functional shell

    International Nuclear Information System (INIS)

    Human serum albumin (HSA) is a protein found in human blood. Over the last decade, HSA has been evaluated as a promising drug carrier. However, not being magnetic, HSA cannot be used for biomedical applications such as magnetic resonance imaging (MRI) and magnetic drug targeting. Therefore, subsequent composites building on iron oxide nanoparticles that are already used clinically as MRI contrast agents are extensively studied. Recently and in this context, innovative fully hydrophilic ultra-small CAN-stabilized maghemite ((CeLn)3/4+-γ-Fe2O3) nanoparticles have been readily fabricated. The present study discusses the design, fabrication, and characterization of a dual phase hybrid core (rHSA)-shell ((CeLn)3/4+-γ-Fe2O3 NPs) nanosystem. Quite importantly and in contrast to widely used encapsulation strategies, rHSA NP surface-attached (CeLn)3/4+-γ-Fe2O3 NPs enabled to exploit both rHSA (protein functionalities) and (CeLn)3/4+-γ-Fe2O3 NP surface functionalities (COOH and ligand L coordinative exchange) in addition to very effective MRI contrast capability due to optimal accessibility of H2O molecules with the outer magnetic phase. Resulting hybrid nanoparticles might be used as a platform modular system for therapeutic (drug delivery system) and MR diagnostic purposes. (paper)

  17. Towards hybrid biocompatible magnetic rHuman serum albumin-based nanoparticles: use of ultra-small (CeLn)3/4+ cation-doped maghemite nanoparticles as functional shell

    Science.gov (United States)

    Israel, Liron L.; Kovalenko, Elena I.; Boyko, Anna A.; Sapozhnikov, Alexander M.; Rosenberger, Ina; Kreuter, Jörg; Passoni, Lorena; Lellouche, Jean-Paul

    2015-01-01

    Human serum albumin (HSA) is a protein found in human blood. Over the last decade, HSA has been evaluated as a promising drug carrier. However, not being magnetic, HSA cannot be used for biomedical applications such as magnetic resonance imaging (MRI) and magnetic drug targeting. Therefore, subsequent composites building on iron oxide nanoparticles that are already used clinically as MRI contrast agents are extensively studied. Recently and in this context, innovative fully hydrophilic ultra-small CAN-stabilized maghemite ((CeLn)3/4+-γ-Fe2O3) nanoparticles have been readily fabricated. The present study discusses the design, fabrication, and characterization of a dual phase hybrid core (rHSA)-shell ((CeLn)3/4+-γ-Fe2O3 NPs) nanosystem. Quite importantly and in contrast to widely used encapsulation strategies, rHSA NP surface-attached (CeLn)3/4+-γ-Fe2O3 NPs enabled to exploit both rHSA (protein functionalities) and (CeLn)3/4+-γ-Fe2O3 NP surface functionalities (COOH and ligand L coordinative exchange) in addition to very effective MRI contrast capability due to optimal accessibility of H2O molecules with the outer magnetic phase. Resulting hybrid nanoparticles might be used as a platform modular system for therapeutic (drug delivery system) and MR diagnostic purposes.

  18. 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

  19. Synthesis and comparative study on the antimicrobial activity of hybrid materials based on silver nanoparticles (AgNps) stabilized by polyvinylpyrrolidone (PVP).

    Science.gov (United States)

    Bryaskova, Rayna; Pencheva, Daniela; Nikolov, Stanislav; Kantardjiev, Todor

    2011-10-01

    Hybrid materials based on polyvinylpyrrolidone (PVP) with silver nanoparticles (AgNps) were synthesized applying two different strategies based on thermal or chemical reduction of silver ions to silver nanoparticles using PVP as a stabilizer. The formation of spherical silver nanoparticles with diameter ranging from 9 to 16 nm was confirmed by TEM analysis. UV-vis and FTIR spectroscopy were also applied to confirm the successful formation of AgNps. The antibacterial activity of the synthesized AgNPs/PVP against etalon strains of three different groups of bacteria-Staphylococcus aureus (S. aureus; gram-positive bacteria), Escherichia coli (E. coli; gram-negative bacteria), Pseudomonas aeruginosa (P. aeruginosa; non-ferment gram-negative bacteria), as well as against spores of Bacillus subtilis (B. subtilis) was studied. AgNps/PVP were tested for the presence of fungicidal activity against different yeasts and mold such as Candida albicans, Candida krusei, Candida tropicalis, Candida glabrata, and Aspergillus brasiliensis. The hybrid materials showed a strong antimicrobial effect against the tested bacterial and fungal strains and therefore have potential applications in biotechnology and biomedical science. PMID:22837793

  20. 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)

  1. Towards solution-processed ambipolar hybrid thin-film transistors based on ZnO nanoparticles and P3HT polymer

    Science.gov (United States)

    Diallo, Abdou Karim; Gaceur, Meriem; Berton, Nicolas; Margeat, Olivier; Ackermann, Jörg; Videlot-Ackermann, Christine

    2013-06-01

    Solution-processed n-channel oxide semiconductor thin-film transistors (TFTs) were fabricated using zinc oxide (ZnO) nanoparticles. Polycrystalline fused-ZnO nanoparticle films were produced by spin-coating ZnO nanosphere dispersions following by a subsequent heat treatment. The solution-processable semiconductor ink based on ZnO was prepared by dispersing the synthesized ZnO nanospheres in isopropanol mixed with ethanolamine to various concentrations from 20 to 80 mg/mL. Such concentration dependence on morphology and microstructure of thin films was studied on spin-coated ZnO films by scanning electron microscopy (SEM) and X-ray diffraction (XRD). Spin-coated ZnO films involved as active layers in transistor configuration delivered an almost ideal output characteristic (Id-Vd) with an electron mobility up to 3 × 10-2 cm2/V s. As a p-channel semiconductor, a poly(3-hexylthiophene) (P3HT) solution-processable ink was deposited by spin-coating on top of closely packed ZnO nanoparticles-based films to form an uniform overlying layer. A hybrid (inorganic-organic) interface was formed by the direct contact between ZnO and P3HT leading to carrier redistribution. Such solution-processed hybrid thin-film transistors delivered in air well balanced electron and hole mobilities as 3.9 × 10-5 and 2 × 10-5 cm2/V s, respectively.

  2. 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

  3. Synthesis of Ag/CNT hybrid nanoparticles and fabrication of their Nylon-6 polymer nanocomposite fibers for antimicrobial applications

    International Nuclear Information System (INIS)

    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 ∼ 80 μm 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 μg 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 μg 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 strains tested. Further, the

  4. 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.

  5. Charge collection enhancement by incorporation of gold-silica core-shell nanoparticles into P3HT:PCBM/ZnO nanorod array hybrid solar cells.

    Science.gov (United States)

    Wang, Ting-Chung; Su, Yen-Hsun; Hung, Yun-Kai; Yeh, Chen-Sheng; Huang, Li-Wen; Gomulya, Widianta; Lai, Lai-Hung; Loi, Maria A; Yang, Jih-Sheng; Wu, Jih-Jen

    2015-08-14

    In this work, gold-silica core-shell (Au@silica) nanoparticles (NPs) with various silica-shell thicknesses are incorporated into P3HT:PCBM/ZnO nanorod (NR) hybrid solar cells. Enhancement in the short-circuit current density and the efficiency of the hybrid solar cells is attained with the appropriate addition of Au@silica NPs regardless of the silica-shell thickness. Compared to the P3HT:PCBM/ZnO NR hybrid solar cell, a 63% enhancement in the efficiency is achieved by the P3HT:PCBM/Au@silica NP/ZnO NR hybrid solar cell. The finite difference time domain simulations indicate that the strength of the Fano resonance, i.e., the electric field of the quasi-static asymmetric quadrupole, on the surface of Au@silica NPs in the P3HT:PCBM/ZnO NR hybrid significantly decreases with increasing thickness of the silica shell. Raman characterization reveals that the degree of P3HT order increases when Au@silica NPs are incorporated into the P3HT:PCBM/ZnO NR hybrid. The charge separation at the interface between P3HT and PCBM as well as the electron transport in the active layer are retarded by the electric field of the Fano resonance. Nevertheless, the prolongation of the electron lifetime and the reduction of the electron transit time in the P3HT:PCBM/ZnO NR hybrid solar cells, which result in an enhancement of electron collection, are achieved by the addition of Au@silica NPs. This may be attributed to the improvement in the degree of P3HT order and connectivity of PCBM when Au@silica NPs are incorporated into the P3HT:PCBM active layer. PMID:26159896

  6. Development of Hybrid Organic/Inorganic Nanocomposite Coating by Electron Beam Curing of Bisphenol a Diglycidyl Ether Diacrylate Containing Surface Modified Silica Nanoparticles

    International Nuclear Information System (INIS)

    The conventional curing processes use solvent-based chemicals formulations, which create environmental pollution by emitting large amount of hazardous air pollutants (HAP) into the atmosphere. Increased awareness regarding the environment, energy conservation, economics and better performance of products have emerged as the driving force to switch from conventional curing to radiation curing process. Nanocomposite material that exhibits a change in structure and composition over nanometer scale have been found to show remarkable property enhancement like scratch resistance, wear resistance, impact resistance, barrier properties and flame retardant property. The aim of the present work was to develop hybrid organic/inorganic nanocomposites clear coatings by electron beam curing of coating formulation (Bisphenol A diglycidyl ether diacrylate mixed with 1,6-hexandioldiacrylate) containing silica nanoparticles. Silica nanoparticles were modified by radiation grafting of vinyl monomers e.g. GMA, HEMA, before dispersing them into coating compositions, for better compatibility with non-polar coating formulations. The rheological behaviour of nanocomposite coating formulations was evaluated using Brookfield viscometer and found to exhibit psuedoplastic type non-newtonian behaviour. The nanocomposites coatings cured on glass sheets were tested for end performance properties viz. abrasion resistance (ASTM: D4060-01), Gloss at 60 degree angle (ASTM: D 523-99)] and pencil hardness (ASTM: D 3363-00). It was found that incorporation of silica nanoparticles into coating formulation improves abrasion resistance property of coating significantly. Gloss of coating reduced significantly upon addition of silica nanoparticles suggesting that the silica nanoparticles could be used as effective matting agent. Moreover, modification of silica nanoparticles further improves abrasion, pencil hardness and gloss of the coating significantly

  7. 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

  8. 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.

  9. Influence of morphology and polymer:nanoparticle ratio on device performance of hybrid solar cells—an approach in experiment and simulation

    International Nuclear Information System (INIS)

    We present a thorough study on the various impacts of polymer:nanoparticle ratios on morphology, charge generation and device performance in hybrid solar cells, comprising active layers consisting of a conjugated polymer and in situ prepared copper indium sulfide (CIS) nanoparticles. We conducted morphological studies through transmission electron microscopy and transient absorption measurements to study charge generation in absorber layers with polymer:nanoparticle weight ratios ranging from 1:3 to 1:15. These data are correlated to the characteristic parameters of the prepared solar cells. To gain a deeper understanding of our experimental findings, three-dimensional drift-diffusion-based simulations were performed. Based on elaborate descriptions of the contributions of polymer and nanoparticle phase to device performances, our results suggest that a polymer:CIS volume ratio of 1:2 (weight ratio 1:9) is necessary to obtain a balanced hole and electron percolation. Also at higher CIS loadings the photocurrent remains surprisingly high due to the contribution of the CIS phase to the charge carrier generation. (paper)

  10. 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

  11. 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.

  12. 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.

  13. 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.

  14. 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.

  15. 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

  16. 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.

  17. Conjugated Polymer-Based Hybrid Nanoparticles with Two-Photon Excitation and Near-Infrared Emission Features for Fluorescence Bioimaging within the Biological Window.

    Science.gov (United States)

    Lv, Yanlin; Liu, Peng; Ding, Hui; Wu, Yishi; Yan, Yongli; Liu, Heng; Wang, Xuefei; Huang, Fei; Zhao, Yongsheng; Tian, Zhiyuan

    2015-09-23

    Hybrid fluorescent nanoparticles (NPs) capable of fluorescing near-infrared (NIR) light (centered ∼730 nm) upon excitation of 800 nm laser light were constructed. A new type of conjugated polymer with two-photon excited fluorescence (TPEF) feature, P-F8-DPSB, was used as the NIR-light harvesting component and the energy donor while a NIR fluorescent dye, DPA-PR-PDI, was used as the energy acceptor and the NIR-light emitting component for the construction of the fluorescent NPs. The hybrid NPs possess δ value up to 2.3 × 10(6) GM per particle upon excitation of 800 nm pulse laser. The excellent two-photon absorption (TPA) property of the conjugated polymer component, together with its high fluorescence quantum yield (ϕ) up to 45% and the efficient energy transfer from the conjugated polymer to NIR-emitting fluorophore with efficiency up to 90%, imparted the hybrid NPs with TPEF-based NIR-input-NIR-output fluorescence imaging ability with penetration depth up to 1200 μm. The practicability of the hybrid NPs for fluorescence imaging in Hela cells was validated. PMID:26340609

  18. 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

  19. A facile "turn-on" fluorescent method with high sensitivity for Hg(2+) detection using magnetic Fe3O4 nanoparticles and hybridization chain reactions.

    Science.gov (United States)

    Lv, Xiaoxiao; Wu, Wenchen; Niu, Chenggang; Huang, Dawei; Wang, Xiaoyu; Zhang, Xuegang

    2016-05-01

    In this manuscript, the authors molecularly engineered a hybridization chain reactions (HCRs) based probe on magnetic Fe3O4 nanoparticles for the sensitive detection of Hg(2+). The sensing system comprised three probes: capture probe H1, report probe H2, and report probe H3. The capture probe was modified on the surface of magnetic Fe3O4 nanoparticles. The report probes were labeled with fluorescein isothiocyanate (FITC). Without Hg(2+), the report probes were stable as molecular beacons in solution. In the presence of Hg(2+), the T-rich capture probes and report probes will hybridize into double-helical DNA domains with the aid of T-Hg(2+)-T coordination chemistry. Trigged by this reaction, more molecular beacons open and form a super tandem structure. Herein, the fluorescence signal was magnified by capturing more report probes. Separating the target and captured report probes from reaction solution was benefit to decrease the background signal and interference from other metal ions. The detection limit of this method was about 0.36nM, which is much lower than the regulations of World Health Organization and U.S. Environmental Protection Agency on Hg(2+) in drink water. This proposed sensing strategy also showed favorable selectivity over other common metal ions. In addition, it has good practicability in real water samples. PMID:26946010

  20. 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

  1. Ultra-small lipid-dendrimer hybrid nanoparticles as a promising strategy for antibiotic delivery: In vitro and in silico studies.

    Science.gov (United States)

    Sonawane, Sandeep J; Kalhapure, Rahul S; Rambharose, Sanjeev; Mocktar, Chunderika; Vepuri, Suresh B; Soliman, Mahmoud; Govender, Thirumala

    2016-05-17

    The purpose of this study was to explore the preparation of a new lipid-dendrimer hybrid nanoparticle (LDHN) system to effectively deliver vancomycin against methicillin-resistant Staphylococcus aureus (MRSA) infections. Spherical LDHNs with particle size, polydispersity index and zeta potential of 52.21±0.22nm, 0.105±0.01, and -14.2±1.49mV respectively were prepared by hot stirring and ultrasonication using Compritol 888 ATO, G4 PAMAM- succinamic acid dendrimer, and Kolliphor RH-40. Vancomycin encapsulation efficiency (%) in LDHNs was almost 4.5-fold greater than in lipid-polymer hybrid nanoparticles formulated using Eudragit RS 100. Differential scanning calorimetry and Fourier transform-infrared studies confirmed the formation of LDHNs. The interactions between the drug-dendrimer complex and lipid molecules using in silico modeling revealed the molecular mechanism behind the enhanced encapsulation and stability. Vancomycin was released from LDHNs over the period of 72h with zero order kinetics and super case II transport mechanism. The minimum inhibitory concentration (MIC) against S. aureus and MRSA were 15.62μg/ml and 7.81μg/ml respectively. Formulation showed sustained activity with MIC of 62.5μg/ml against S. aureus and 500μg/ml against MRSA at the end of 72 and 54h period respectively. The results suggest that the LDHN system can be an effective strategy to combat resistant infections. PMID:26992817

  2. 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.

  3. 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.

  4. 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

  5. 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. PMID:27203688

  6. 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

  7. 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/S2O82− 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

  8. Efficient Synthesis of a Maghemite/Gold Hybrid Nanoparticle System as a Magnetic Carrier for the Transport of Platinum-Based Metallotherapeutics

    Directory of Open Access Journals (Sweden)

    Pavel Štarha

    2015-01-01

    Full Text Available The preparation and thorough characterization of a hybrid magnetic carrier system for the possible transport of activated platinum-based anticancer drugs, as demonstrated for cisplatin (cis-[Pt(NH32Cl2], CDDP, are described. The final functionalized mag/Au–LA–CDDP* system consists of maghemite/gold nanoparticles (mag/Au coated by lipoic acid (HLA; LA stands for deprotonated form of lipoic acid and functionalized by activated cisplatin in the form of cis-[Pt(NH32(H2O2]2+ (CDDP*. The relevant techniques (XPS, EDS, ICP-MS proved the incorporation of the platinum-containing species on the surface of the studied hybrid system. HRTEM, TEM and SEM images showed the nanoparticles as spherical with an average size of 12 nm, while their superparamagnetic feature was proven by 57Fe Mössbauer spectroscopy. In the case of mag/Au, mag/Au–HLA and mag/Au–LA–CDDP*, weaker magnetic interactions among the Fe3+ centers of maghemite, as compared to maghemite nanoparticles (mag, were detected, which can be associated with the non-covalent coating of the maghemite surface by gold. The pH and time-dependent stability of the mag/Au–LA–CDDP* system in different media, represented by acetate (pH 5.0, phosphate (pH 7.0 and carbonate (pH 9.0 buffers and connected with the release of the platinum-containing species, showed the ability of CDDP* to be released from the functionalized nanosystem.

  9. 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

  10. 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.

  11. 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. PMID:26198972

  12. Photovoltage method for the research of CdS and ZnO nanoparticles and hybrid MEH-PPV/nanoparticle structures

    Czech Academy of Sciences Publication Activity Database

    Toušková, J.; Toušek, J.; Rohovec, Jan; Růžička, A.; Polonskyi, O.; Urbánek, P.; Kuřitka, I.

    2014-01-01

    Roč. 16, č. 3 (2014), Art. 2314. ISSN 1388-0764 Institutional support: RVO:67985831 Keywords : CdS * energy conversion * MEH-PPV * nanoparticles * photovoltage spectra * transmission electron microscopy * ZnO Subject RIV: DD - Geochemistry Impact factor: 2.184, year: 2014

  13. Novel magnetite nanoparticle based on BODIPY as fluorescent hybrid material for Ag(I) detection in aqueous medium.

    Science.gov (United States)

    Kursunlu, Ahmed Nuri; Ozmen, Mustafa; Guler, Ersin

    2016-06-01

    This manuscript describes a highly selective and ultra-sensitive detection of Ag(I) in aqueous solution using amine coated magnetite nanoparticles modified boron-dipyrromethene by spectrofluorometer. Fe3O4 nanoparticles were synthesized by co-precipitation of Fe(2+)and Fe(3+)in an ammonia solution. Amine modified Fe3O4 was prepared by using (3-aminopropyl)triethoxysilane as silanization agent. The covalent binding of boron-dipyrromethene to amine modified Fe3O4 was confirmed by means of Fourier Transform infrared spectroscopy, transmission electron microscopy, dynamic light scattering, UV-vis and fluorimeter measurements and obtained nanoparticle-boron dipyrromethene structure. The binding abilities of nanoparticle-boron dipyrromethene towards different metal ions have been investigated by some spectroscopic methods as UV-vis, fluorescence spectroscopy, Job plot, etc. and the novel surface displayed high selectivity and sensitivity for Ag(I) among all tested metals. PMID:27130108

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

    OpenAIRE

    Balazs Farkas; Marina Rodio; Ilaria Romano; Alberto Diaspro; Romuald Intartaglia; Szabolcs Beke

    2015-01-01

    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...

  15. 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.

  16. Electrochemical fabrication of TiO2 nanoparticles/[BMIM]BF4 ionic liquid hybrid film electrode and its application in determination of p-acetaminophen

    International Nuclear Information System (INIS)

    A water soluble ionic liquid, 1‐butyl‐3‐methylimidazolium tetrafluoroborate ([BMIM]BF4), was incorporated into TiO2 nanoparticles to fabricate a hybrid film modified glassy carbon electrode (nano‐TiO2/[BMIM]BF4/GCE) through electrochemical deposition in a tetrabutyltitanate sol solution containing [BMIM]BF4. The obtained nano‐TiO2/[BMIM]BF4/GCEs were characterized scanning electronic microscopy (SEM) and X‐ray photoelectron spectroscopy (XPS). Electrochemical behaviors of p‐acetaminophen at the nano‐TiO2/[BMIM]BF4/GCEs were thoroughly investigated. Compared to the redox reaction of p‐acetaminophen using an unmodified electrode under the same conditions, a new reduction peak was observed clearly at 0.26 V with the modified electrode. In addition, the peak potential for the oxidation of p‐acetaminophen was found to shift negatively about 90 mV and the current response increased significantly. These changes indicate that the nano‐TiO2/[BMIM]BF4 hybrid film can improve the redox reactions of p‐acetaminophen in aqueous medium. Under optimum conditions, a linear relationship was obtained for the p‐acetaminophen solutions with concentration in the range from 5.0 × 10−8 to 5.0 × 10−5 M. The estimated detection limit was 1.0 × 10−8 M (S/N = 3). The newly developed method was applied for the determination of p-acetaminophen in urine samples. - Highlights: ► Nano-TiO2/[BMIM]BF4 hybrid film electrode was fabricated with electrodeposition. ► Voltammetric behavior of p-acetaminophen at the obtained electrode was investigated. ► The hybrid film electrode shows good electrocatalytic response to p-acetaminophen. ► p-acetaminophen in urine samples was successfully determined.

  17. 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

  18. 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

  19. 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.

  20. Highly sensitive gold nanoparticles-based optical sensing of DNA hybridization using bis(8-hydroxyquinoline-5-solphonate)cerium(III) chloride as a novel fluorescence probe.

    Science.gov (United States)

    Shamsipur, Mojtaba; Memari, Zahra; Ganjali, Mohammad Reza; Norouzi, Parviz; Faridbod, Farnoush

    2016-01-25

    A simple and sensitive method for the detection of DNA hybridization in a homogeneous format was developed, using bis(8-hydroxyquinoline-5-solphonate)cerium(III) chloride (Ce(QS)2Cl) as a novel fluorescent probe. The method is based on fluorescence quenching by gold nanoparticles used as both nanoscafolds for the immobilization of the probe DNA sequence, which is related to Alicyclobacillus acidophilus strain TA-67 16S ribosomal RNA, and nanoquenchers of the Ce(QS)2Cl probe. The probe DNA-functionalized GNPs were synthesized by derivatizing the colloidal gold nanoparticles solution with 3-thiolated 16-base oligonucleotides. Addition of sequence-specific target DNAs (16 bases) into the mixture containing probe DNA-functionalized GNPs and fluorescent probe lead to the quenching of Ce(QS)2Cl fluorescence at 360 nm (λex=270 nm), due to DNA hybridization, the resulting quenched intensity being proportional to the concentration of target DNA. Under optimal conditions of pH 7.4 and Ce(QS)2Cl concentration of 1.0 × 10(-7) M, the linear dynamic range found to be 1.0 × 10(-10)-3.0 × 10(-8) M DNA, with a limit of detection of 7.0 × 10(-11) M. The interaction mechanism for the binding of Ce(QS)2Cl to DNA was studied in detail, and results proved that the interaction mode between Ce(QS)2Cl and DNA is groove binding, with a binding constant of 1.0 × 10(5) M(-1). PMID:26600117

  1. Magnetic, optical and relaxometric properties of organically coated gold-magnetite (Au-Fe{sub 3}O{sub 4}) hybrid nanoparticles for potential use in biomedical applications

    Energy Technology Data Exchange (ETDEWEB)

    Umut, E., E-mail: eumut@hacettepe.edu.tr [Hacettepe University Physics Engineering Department, 06800 Beytepe-Ankara (Turkey); Pineider, F. [INSTM and Universita degli Studi di Firenze, Department of Chemistry, Via della Lastruccia 3, 50019 Sesto Fiorentino (Italy); CNR-ISTM Padova, 35131 Padova (Italy); Arosio, P. [INSTM and Universita degli Studi di Milano, Department of Molecular Sciences Applied to Biosystems (DISMAB), I-20134 Milano (Italy); Sangregorio, C. [INSTM and Universita degli Studi di Firenze, Department of Chemistry, Via della Lastruccia 3, 50019 Sesto Fiorentino (Italy); CNR-ISTM Milano, 50123 via C.Golgi 19, 20133 Milano (Italy); Corti, M. [INSTM, CNISM and Dipartimento di Fisica ' A.Volta' , Univ. di Pavia, Via Bassi 6, I-27100 Pavia (Italy); Tabak, F. [Hacettepe University Physics Engineering Department, 06800 Beytepe-Ankara (Turkey); Lascialfari, A. [INSTM and Universita degli Studi di Milano, Department of Molecular Sciences Applied to Biosystems (DISMAB), I-20134 Milano (Italy); INSTM, CNISM and Dipartimento di Fisica ' A.Volta' , Univ. di Pavia, Via Bassi 6, I-27100 Pavia (Italy); Ghigna, P. [INSTM and Dipartimento di Chimica Univ. di Pavia, v.le Taramelli 13, I-27100 Pavia (Italy)

    2012-08-15

    We present the magnetic, optical and relaxometric properties of multifunctional Au-Fe{sub 3}O{sub 4} hybrid nanoparticles (HNPs), as possible novel contrast agents (CAs) for magnetic resonance imaging (MRI). The HNPs have been synthesized by wet chemical methods in heterodimer and core-shell geometries and capped with oleylamine. Structural characterization of the samples have been made by X-ray diffraction and transmission electron microscopy, while magnetic properties have been investigated by means of Superconducting Quantum Interference Device-SQUID magnetometry experiments. As required for MRI applications using negative CAs, the samples resulted superparamagnetic at room temperature and well above their blocking temperatures. Optical properties have been investigated by analyzing the optical absorbtion spectra collected in UV-visible region. Relaxometric measurements have been performed on organic suspensions of HNPs and Nuclear Magnetic Resonance (NMR) dispersion curves have been obtained by measuring the longitudinal 1/T{sub 1} and transverse 1/T{sub 2} relaxation rates of solvent protons in the range 10 kHz/300 MHz at room temperature. NMR relaxivities r{sub 1} and r{sub 2} have been compared with ENDOREM{sup Registered-Sign }, one of the commercial superparamagnetic iron oxide based MRI contrast agents. MRI contrast enhancement efficiencies have been investigated also by examining T{sub 2}-weighted MR images of suspensions. The experimental results suggest that the nanoparticles' suspensions are good candidates as negative CAs. - Highlights: Black-Right-Pointing-Pointer Au-Fe{sub 3}O{sub 4} superparamagnetic Hybrid NanoPrticles (HNPs) enhance contrast in MRI. Black-Right-Pointing-Pointer HNPs are expected to have optical activities through observed SPR phenomena. Black-Right-Pointing-Pointer HNPs have relatively high magnetic anisotropy originating from Au/Fe{sub 3}O{sub 4} interface. Black-Right-Pointing-Pointer Magnetic dipolar interactions have

  2. Synthesis of an optically clear, flexible and stable hybrid ureasilicate matrix doped with CdSe nanoparticles produced by reverse micelles

    International Nuclear Information System (INIS)

    Optically clear and flexible organic–inorganic hybrid materials doped with CdSe nanoparticles (NPs) were synthesized by a sol–gel method based on the hydrolysis and condensation reactions of ureasilicate precursors. The CdSe NPs were produced by a colloidal method using reverse micelles and were then transferred to the ureasilicate precursor solution followed by gelation of the mixture using ammonia/water vapours as catalyst for the sol–gel process. The influence of the NPs surface in the dispersion of the NPs within the matrix was investigated by the addition of a capping agent with both thiol and siloxane groups (3-mercaptopropyltrimethoxysilane, MPTMS). This capping agent was used in order to improve compatibility and avoid aggregation of the NPs within the matrix and to increase the preservation of the original optical properties of the NPs. The nanocomposites obtained were characterized by absorption spectroscopy, steady-state photoluminescence, time resolved photoluminescence, HRTEM and FTIR spectroscopy. The results obtained showed the influence of the use of MPTMS in the preservation of the original optical properties of the CdSe NPs after their transfer into the ureasilicate matrix. The HRTEM analysis showed the presence of well-dispersed spherical NPs with well-defined lattice fringes. The obtained nanocomposites exhibit high transparency in the visible range as a result of the good dispersion of the NPs within the matrix, showing the potentials of the developed method in the production of composite materials in which the optical properties of the NPs incorporated are crucial to the desired application. - Highlights: • Synthesis of a hybrid ureasilicate matrix doped with CdSe nanoparticles. • Absorption and PL spectra of doped xerogels show features of quantum size effect. • Using MPTMS plays an important role in the optical properties of the nanocomposites. • HRTEM analysis showed well-dispersed spherical NPs with well-defined lattice

  3. 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

  4. 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. PMID:26894290

  5. Dual Stimuli-Responsive Hybrid Polymeric Nanoparticles Self-Assembled from POSS-Based Starlike Copolymer-Drug Conjugates for Efficient Intracellular Delivery of Hydrophobic Drugs.

    Science.gov (United States)

    Yang, Qingqing; Li, Lian; Sun, Wei; Zhou, Zhou; Huang, Yuan

    2016-06-01

    To further fine tune drug release and enhance therapeutic effects of polyhedral oligomericsilsesquioxane (POSS)-based nanomedicine, a starlike organic-inorganic conjugate was synthesized by grafting semitelechelic N-(2-hydroxypropyl) methacrylamide (HPMA) copolymers to a POSS rigid core through reductively degradable disulfide bonds. The hydrophobic docetaxel (DTX) was attached to the grafts by pH-sensitive hydrazone bonds and also encapsulated into the POSS core (SP-DTX). Thus, the final amphiphilic star-shaped conjugates could self-assemble into nanoparticles and exhibited conspicuous drug-loading capacity (20.1 wt %) based on the covalently conjugated accompanied by physically encapsulated DTX. The stimuli-responsive DTX release under acidic lysosomal and reducing cytoplasmic environments was verified, leading to enhanced cytotoxicity against PC-3 human prostate carcinoma cells. To evaluate the in vivo therapeutic effects of the DTX-loaded nanovehicles objectively, a stroma-rich, prostate xenograft tumor model was generated. SP-DTX displayed uniform tumor distribution and suppressed tumor growth to a more pronounced level (tumor inhibition of 78.9%) than nonredox-sensitive SP-DTX-A (67.4%), SP-DTX-C contained DTX only in the core (65.5%) or linear P-DTX (60.7%) through enhanced depletion of cancer-associated fibroblasts and induction of apoptosis. The hybrid POSS-based polymeric nanoparticles offer an efficient approach to transport hydrophobic drugs for cancer therapy. PMID:27167898

  6. 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.

  7. Extended short-wavelength spectral response of organic/(silver nanoparticles/Si nanoholes nanocomposite films) hybrid solar cells due to localized surface plasmon resonance

    International Nuclear Information System (INIS)

    Highlights: • The silver nanoparticles (AgNPs)/Si nanoholes (SiNHs) nanocomposite films were fabricated. • An enhancement of total absorption in the AgNPs/SiNHs nanocomposite films at the short wavelength was exhibited. • Prototype solar cell device with AgNPs exhibits an increase of the power conversion efficiency by a factor of 2–3. - Abstract: In this letter, we investigated spectral and opto-electronic conversion properties of the inorganic/organic hybrid cells by using silver nanoparticles (AgNPs)/Si nanoholes (SiNHs) nanocomposite films, which were fabricated by the modified metal-assisted electroless etching (EE) method. It was found that the optical absorption spectra of the films with AgNPs demonstrate a clear peak and show the enhancement of total absorption at the short wavelength. The results of current–voltage (I–V) measurements show that solar cells with AgNPs exhibit an increase of the power conversion efficiency by a factor of 2–3, in comparison with those of the samples without AgNPs. Moreover, higher external quantum efficiency (EQE) values in AgNPs-decorated solar cells were confirmed in the short-wavelength spectral region (400–700 nm), which were essential to achieve high-performance photovoltaic cells. We thought these were mainly attributed to the localized surface plasmon resonance (LSPR) effects and increased light scattering of AgNPs

  8. 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.

  9. Hybrid fluorescent nanoparticles fabricated from pyridine-functionalized polyfluorene-based conjugated polymer as reversible pH probes over a broad range of acidity-alkalinity

    International Nuclear Information System (INIS)

    Conjugated polymer nanoparticles (CPNs) were developed based on a polyfluorene-based conjugated polymer with thiophene units carrying pyridyl moieties incorporated in the backbone of polymer chains (PFPyT). Hybrid CPNs fabricated from PFPyT and an amphiphilic polymer (NP1) displayed pH-sensitive fluorescence emission features in the range from pH 4.8 to 13, which makes them an attractive nanomaterial for wide range optical sensing of pH values. The fluorescence of hybrid CPNs based on chemically close polyfluorene derivatives without pyridyl moieties (NP3), in contrast, remains virtually unperturbed by pH values in the same range. The fluorescence emission features of NP1 underwent fully reversible changes upon alternating acidification/basification of aqueous dispersions of the CPNs and also displayed excellent repeatability. The observed pH sensing properties of NP1 are attributed to protonation/deprotonation of the nitrogen atoms of the pyridine moieties. This, in turn, leads to the redistribution of electron density of pyridine moieties and their participation in the π-conjugation within the polymer main chains. The optically transparent amphiphilic polymers also exerted significant influence on the pH sensing features of the CPNs, likely by acting as proton sponge and/or acid chaperone. (author)

  10. 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.

  11. 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

    2016-07-15

    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. PMID:27251019

  12. 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.

  13. Photo-induced green synthesis and antimicrobial efficacy of poly (ɛ-caprolactone)/curcumin/grape leaf extract-silver hybrid nanoparticles.

    Science.gov (United States)

    El-Sherbiny, Ibrahim M; El-Shibiny, Ayman; Salih, Ehab

    2016-07-01

    This study reports the photo-induced green synthesis and antimicrobial assessment of poly(ɛ-caprolactone)/curcumin/grape leaf extract-Ag hybrid nanoparticles (PCL/Cur/GLE-Ag NPs). PCL/Cur/GLE NPs were synthesized via emulsion-solvent evaporation in the presence of PVA as a capping agent, then used as active nano-supports for the green synthesis and stabilization of AgNPs on their surfaces. Both Cur and GLE were selected and incorporated into the PCL nano-supports due to their reported promising antimicrobial activity that would further enhance that of the synthesized AgNPs. The developed PCL/Cur/GLE NPs and PCL/Cur/GLE-Ag hybrid NPs were characterized using UV-visible spectrophotometry, high resolution transmission electron microscopy (HRTEM) and X-ray diffraction (XRD). HRTEM images showed that the PCL/Cur/GLE NPs are monodispersed and spherical with size of about 270nm, and the AgNPs were formed mainly on their surfaces with average size in the range 10-30nm. The synthesized AgNPs were found to be crystalline as shown by XRD patterns with fcc phase oriented along the (111), (200), (220) and (311) planes. The antimicrobial characteristics of the newly developed NPs were investigated against gram-positive and gram-negative bacteria in addition to two fungal strains. The results demonstrated that the PCL/Cur/GLE-Ag hybrid NPs have a potential antimicrobial activity against pathogenic bacterial species and could be considered as an alternative antibacterial agent. PMID:27183490

  14. Red florescent Ag2S-CdS hybrid nanoparticles prepared by a one pot and rapid microwave method

    Science.gov (United States)

    Karimipour, Masoud; Molaei, Mehdi

    2016-03-01

    In this work, Ag2S-CdS hybrid composite with novel luminescence property was synthesized using a one pot and rapid microwave method. Structural analysis by means of XRD and TEM obtained the formation of the composite. Optical spectroscopy by means of UV-Vis and Photoluminescence measurements revealed that the functional composite has an intensive red light emission at 657 nm with a large stocks shift of about 150 nm. The quantum efficiency of the prepared hybrid material in red region is 10% which is comparable with the efficiency of pure CdS (11%) with green emission. [Figure not available: see fulltext.

  15. 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.

  16. 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

  17. 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...

  18. 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.

  19. 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.

  20. Electrochemical fabrication of TiO{sub 2} nanoparticles/[BMIM]BF{sub 4} ionic liquid hybrid film electrode and its application in determination of p-acetaminophen

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Bin; Li, Yuan; Qin, Xianjing; Zhan, Guoqing [Key Laboratory of Analytical Chemistry of the State Ethnic Affairs Commission, College of Chemistry and Materials Science, South-Central University for Nationalities, Wuhan 430074 (China); Ma, Ming [Ningbo Entry-Exit Inspection and Quarantine Bureau of P. R. C., Ningbo 315012 (China); Li, Chunya, E-mail: lcychem@yahoo.com [Key Laboratory of Analytical Chemistry of the State Ethnic Affairs Commission, College of Chemistry and Materials Science, South-Central University for Nationalities, Wuhan 430074 (China)

    2012-12-01

    A water soluble ionic liquid, 1-butyl-3-methylimidazolium tetrafluoroborate ([BMIM]BF{sub 4}), was incorporated into TiO{sub 2} nanoparticles to fabricate a hybrid film modified glassy carbon electrode (nano-TiO{sub 2}/[BMIM]BF{sub 4}/GCE) through electrochemical deposition in a tetrabutyltitanate sol solution containing [BMIM]BF{sub 4}. The obtained nano-TiO{sub 2}/[BMIM]BF{sub 4}/GCEs were characterized scanning electronic microscopy (SEM) and X-ray photoelectron spectroscopy (XPS). Electrochemical behaviors of p-acetaminophen at the nano-TiO{sub 2}/[BMIM]BF{sub 4}/GCEs were thoroughly investigated. Compared to the redox reaction of p-acetaminophen using an unmodified electrode under the same conditions, a new reduction peak was observed clearly at 0.26 V with the modified electrode. In addition, the peak potential for the oxidation of p-acetaminophen was found to shift negatively about 90 mV and the current response increased significantly. These changes indicate that the nano-TiO{sub 2}/[BMIM]BF{sub 4} hybrid film can improve the redox reactions of p-acetaminophen in aqueous medium. Under optimum conditions, a linear relationship was obtained for the p-acetaminophen solutions with concentration in the range from 5.0 Multiplication-Sign 10{sup -8} to 5.0 Multiplication-Sign 10{sup -5} M. The estimated detection limit was 1.0 Multiplication-Sign 10{sup -8} M (S/N = 3). The newly developed method was applied for the determination of p-acetaminophen in urine samples. - Highlights: Black-Right-Pointing-Pointer Nano-TiO{sub 2}/[BMIM]BF{sub 4} hybrid film electrode was fabricated with electrodeposition. Black-Right-Pointing-Pointer Voltammetric behavior of p-acetaminophen at the obtained electrode was investigated. Black-Right-Pointing-Pointer The hybrid film electrode shows good electrocatalytic response to p-acetaminophen. Black-Right-Pointing-Pointer p-acetaminophen in urine samples was successfully determined.

  1. Spectroscopic and microscopic study of hybrid organic-inorganic films prepared in the presence of colloidal polyaniline/silica nanoparticles

    Czech Academy of Sciences Publication Activity Database

    Špírková, Milena; Trchová, Miroslava; Brus, Jiří

    Dourdan : Université Paris 6, 2003. s. A4-23. [Journées Polymeres Conducteurs /10./. 15.09.2003-19.09.2003, Dourdan] R&D Projects: GA ČR GA203/01/0735; GA ČR GA202/02/0698 Institutional research plan: CEZ:AV0Z4050913 Keywords : hybrid organic- inorganic films Subject RIV: BM - Solid Matter Physics ; Magnetism

  2. 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

  3. 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

  4. 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. PMID:26838890

  5. 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

  6. Achieving extremely concentrated aqueous dispersions of graphene flakes and catalytically efficient graphene-metal nanoparticle hybrids with flavin mononucleotide as a high-performance stabilizer.

    Science.gov (United States)

    Ayán-Varela, M; Paredes, J I; Guardia, L; Villar-Rodil, S; Munuera, J M; Díaz-González, M; Fernández-Sánchez, C; Martínez-Alonso, A; Tascón, J M D

    2015-05-20

    The stable dispersion of graphene flakes in an aqueous medium is highly desirable for the development of materials based on this two-dimensional carbon structure, but current production protocols that make use of a number of surfactants typically suffer from limitations regarding graphene concentration or the amount of surfactant required to colloidally stabilize the sheets. Here, we demonstrate that an innocuous and readily available derivative of vitamin B2, namely the sodium salt of flavin mononucleotide (FMNS), is a highly efficient dispersant in the preparation of aqueous dispersions of defect-free, few-layer graphene flakes. Most notably, graphene concentrations in water as high as ∼50 mg mL(-1) using low amounts of FMNS (FMNS/graphene mass ratios of about 0.04) could be attained, which facilitated the formation of free-standing graphene films displaying high electrical conductivity (∼52000 S m(-1)) without the need of carrying out thermal annealing or other types of post-treatment. The excellent performance of FMNS as a graphene dispersant could be attributed to the combined effect of strong adsorption on the sheets through the isoalloxazine moiety of the molecule and efficient colloidal stabilization provided by its negatively charged phosphate group. The FMNS-stabilized graphene sheets could be decorated with nanoparticles of several noble metals (Ag, Pd, and Pt), and the resulting hybrids exhibited a high catalytic activity in the reduction of nitroarenes and electroreduction of oxygen. Overall, the present results should expedite the processing and implementation of graphene in, e.g., conductive inks, composites, and hybrid materials with practical utility in a wide range of applications. PMID:25915172

  7. 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.

  8. Catalytic properties of graphene–metal nanoparticle hybrid prepared using an aromatic amino acid as the reducing agent

    International Nuclear Information System (INIS)

    An easy and single step process of making reduced graphene oxide nanosheet from graphene oxide (GO) in water medium has been demonstrated by using a naturally occurring non-proteinaceous amino acid (2,4-dihydroxy phenyl alanine, Dopa) as a new reducing agent and stabilizing agent. This amino acid has also been used to reduce the noble metal salt (AuCl3/AgNO3) to produce the corresponding noble metal nanoparticles (MNP) without using any external reducing and stabilizing agents. So, this amino acid has been used to reduce simultaneously GO to RGO and noble metal salts to produce corresponding MNP to form RGO–MNP nanohybrid system in a single step in water medium and also in absence of any external toxic reducing and stabilizing agents. Different techniques UV–Visible absorption spectroscopy, X-ray diffraction, transmission electron microscopy, atomic force microscopy and others have been used to characterize the reduction of GO to RGO, metal salts to produce corresponding MNPs and the formation of RGO–MNP nanohybrid systems. Moreover, this metal nanoparticle containing RGO–MNP nanohybrid system acts as a potential catalyst for the reduction of aromatic nitro to aromatic amino group. - Graphical abstract: This study demonstrates an easy, single step and eco-friendly method to make RGO and Au/AgNP simultaneously from respective precursors to form a RGO–Au/AgNP nanohybrid system using an aromatic amino acid (2,4-dihydroxy phenyl alanine, Dopa) as a new reducing agent as well as stabilizing agent in water medium. Highlights: ► Synthesis of reduced graphene oxide (RGO) nanosheet using an amino acid. ► The amino acid (Dopa) can reduce noble metal salt (Au3+/Ag+) to metal nanoparticle (MNP). ► Single step and eco-friendly synthesis of RGO-MNP nanohybrid using Dopa. ► Characterization of RGO, MNP and RGO–MNP nanohybrid. ► RGO-MNP nanohybrid acts as a catalyst for the reduction of aromatic nitro

  9. Hybrid biocomposite with a tunable antibacterial activity and bioactivity based on RF magnetron sputter deposited coating and silver nanoparticles

    International Nuclear Information System (INIS)

    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−1 and 0.54 ± 0.02 μg mL−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

  10. 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.

  11. 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

  12. 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.

  13. iRGD decorated lipid-polymer hybrid nanoparticles for targeted co-delivery of doxorubicin and sorafenib to enhance anti-hepatocellular carcinoma efficacy.

    Science.gov (United States)

    Zhang, Jinming; Hu, Jie; Chan, Hon Fai; Skibba, Melissa; Liang, Guang; Chen, Meiwan

    2016-07-01

    The combination of doxorubicin (DOX) with sorafenib (SOR) has proven an effective strategy to enhance anti-hepatocellular carcinoma (HCC) efficacy. However, respective in vivo pharmacokinetic profiles and different endocytosis capacities of these two drugs greatly hinder their current application. Herein, the tumor-targeting peptide iRGD decorated lipid-polymer hybrid nanoparticles (NPs) with a shell-core structure were developed for co-delivery of DOX and SOR (DOX+SOR/iRGD NPs). After the drug ratio was optimized, the stabilized DOX+SOR/iRGD NPs were prepared. Through the iRGD-integrin recognition, DOX+SOR/iRGD NPs showed synergistic cytotoxicity, pro-apoptotic ability and enhanced internalization rate in human liver cancer HepG2 cells. In vivo pharmacokinetic result demonstrated that an extended circulation and bioavailability of DOX+SOR/iRGD NPs than free drugs. More importantly, DOX+SOR/iRGD NPs significantly enhanced antitumor efficiency in HCC xenograft mouse models. Overall, this study describes a promising nanoparticulate drug co-delivery strategy to combine clinical anticancer drugs and enhance anti-HCC efficacy. PMID:26964482

  14. 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.

  15. 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

  16. Comprehensive Investigation of Silver Nanoparticle/Aluminum Electrodes for Copper Indium Sulfide/Polymer Hybrid Solar Cells

    DEFF Research Database (Denmark)

    Arar, Mario; Pein, Andreas; Haas, Wernfried;

    2012-01-01

    Electrode materials are primarily chosen based on their work function to suit the energy levels of the absorber materials. In this paper, we focus on the modification of aluminum cathodes with a thin silver interlayer (2 nm) in copper indium sulfide/poly[(2,7-silafluorene)-alt-(4,7-di-2-thienyl-2......,1,3-benzothiadiazole)] (PSiF-DBT) nanocomposite solar cells, which improves the fill factor compared to pure aluminum electrodes. A comprehensive structural investigation was performed by means of transmission electron microscopy and time-of-flight secondary ion mass spectrometry revealing the presence of silver...... nanoparticles in an aluminum oxide matrix between the absorber layer and the aluminum cathode. In combination with complementary optical investigations, the origin of the improvement is ascribed to a facilitated charge extraction....

  17. 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

  18. Surface self-assembled hybrid nanocomposites with electroactive nanoparticles and enzymes confined in a polymer matrix for controlled electrocatalysis

    DEFF Research Database (Denmark)

    Zhu, Nan; Ulstrup, Jens; Chi, Qijin

    2015-01-01

    A three-dimensional network of highly branched poly(ethyleneimine) (PEI) is designed and synthesized on gold electrode surfaces. A self-assembled monolayer (SAM) of dithiobis(succinimidyl propionate) (DTSP) on a gold electrode was first prepared, which is confirmed by the reductive desorption of ...... oxidase (GOD) was used towards this end, in a proof-of-concept study. This enzyme can be co-trapped in the PEI matrix and is interconnected with PBNPs, leading to highly efficient electrocatalyic oxidation and detection of glucose.......-S units. The PEI polymer was then covalently immobilized onto the DTSP layer, leaving free primary amine groups acting as a 3D skeleton for high loading of electroactive enzyme-size Prussian blue nanoparticles (PBNPs, 6 nm) via electrostatic trapping. Atomic force microscopy was used to disclose the...... achieved as reflected by a large electron transfer (ET) rate constant (ks) of 200 s-1, and the possible electron propagation mechanisms in the polymer network are discussed. This surface/interfacial nanocomposite can be further used in the accommodation of enzymes for electrochemical bio-catalysis. Glucose...

  19. Effects of laser-induced quenching and restoration of photoluminescence in hybrid Si/SiOx nanoparticles

    International Nuclear Information System (INIS)

    We studied the processes of pulsed and continuous-wave (CW) laser excitation of photoluminescence (PL) in nc-Si/SiOx nanoparticles. CW laser irradiation of the nc-Si/SiOx sol in dimethylsulfoxide (DMSO) and in a thin film was found to quench PL with an essentially nonexponential dynamics. The laser-induced variation of the Rayleigh scattering signal from the nc-Si/SiOx sol in DMSO was found to replicate that of the PL quenching. The IR and Raman spectra of the laser-exposed nc-Si/SiOx exhibited no new bands that could be evidence of their chemical transformations. There were also no perceptible effects pointing to laser-induced aggregation of the nc-Si/SiOx particles in the sol. 355 nm pulse-periodic laser irradiation of the nc-Si/SiOx particles preliminarily exposed to a 405 nm CW laser (which causes a strong PL quenching effect) was found to result in a rapid restoration of the original PL signal, which means that the effect of laser quenching of PL can be entirely reversible. We considered a mechanism of the reversible photosensitivity of nc-Si/SiOx, based on the processes of ionization of the photoluminescent oxygen-deficient centers in their suboxide shell and electron capture by traps, followed by their laser-assisted photorecombination. (letter)

  20. Effects of laser-induced quenching and restoration of photoluminescence in hybrid Si/SiOx nanoparticles

    Science.gov (United States)

    Bagratashvili, V. N.; Dorofeev, S. G.; Ischenko, A. A.; Kononov, N. N.; Panchenko, V. Ya; Rybaltovskii, A. O.; Sviridov, A. P.; Senkov, S. N.; Tsypina, S. I.; Yusupov, V. I.; Yuvchenko, S. A.; Zimnyakov, D. A.

    2013-09-01

    We studied the processes of pulsed and continuous-wave (CW) laser excitation of photoluminescence (PL) in nc-Si/SiOx nanoparticles. CW laser irradiation of the nc-Si/SiOx sol in dimethylsulfoxide (DMSO) and in a thin film was found to quench PL with an essentially nonexponential dynamics. The laser-induced variation of the Rayleigh scattering signal from the nc-Si/SiOx sol in DMSO was found to replicate that of the PL quenching. The IR and Raman spectra of the laser-exposed nc-Si/SiOx exhibited no new bands that could be evidence of their chemical transformations. There were also no perceptible effects pointing to laser-induced aggregation of the nc-Si/SiOx particles in the sol. 355 nm pulse-periodic laser irradiation of the nc-Si/SiOx particles preliminarily exposed to a 405 nm CW laser (which causes a strong PL quenching effect) was found to result in a rapid restoration of the original PL signal, which means that the effect of laser quenching of PL can be entirely reversible. We considered a mechanism of the reversible photosensitivity of nc-Si/SiOx, based on the processes of ionization of the photoluminescent oxygen-deficient centers in their suboxide shell and electron capture by traps, followed by their laser-assisted photorecombination.

  1. Hybrid composite membranes based on polyethylene separator and Al2O3 nanoparticles for lithium-ion batteries.

    Science.gov (United States)

    Shin, Won-Kyung; Lee, Yoon-Sung; Kim, Dong-Won

    2013-05-01

    A hybrid composite membrane is prepared by coating nano-sized Al2O3 powder (13 and 50 nm) and poly(vinylidene fluoride-co-hexafluoropropene) (P(VdF-co-HFP)) binder on both sides of polyethylene separator. The composite membrane shows better thermal stability and improved wettability for organic liquid electrolyte than polyethylene separator, due to the presence of heat-resistant Al2O3 particles with high-surface area in the coating layer. By using the composite membrane, the lithium-ion cells composed of carbon anode and LiNi1/3Co1/3Mn1/3O2 cathode are assembled and their cycling performances are evaluated. The cells assembled with the composite membranes are proven to have better capacity retention than the cell prepared with polyethylene separator, due to the enhanced ability to retain the electrolyte solution in the cell. The cell assembled with the composite membrane containing 13 nm-sized Al2O3 particles has an initial discharge capacity of 173.2 mA h g(-1) with good capacity retention. PMID:23858932

  2. Ceria/POMs hybrid nanoparticles as a mimicking metallopeptidase for treatment of neurotoxicity of amyloid-β peptide.

    Science.gov (United States)

    Guan, Yijia; Li, Meng; Dong, Kai; Gao, Nan; Ren, Jinsong; Zheng, Yongchen; Qu, Xiaogang

    2016-08-01

    Protein misfolding to amyloid aggregates is the hallmark for neurodegenerative disease. While much attention has been paid to screen natural proteases that can degrade amyloid-β peptides (Aβ), it is difficult to apply them in the clinics with the intractable problem of immunogenicity in living organisms. Herein, we rationally designed an artificial nanozyme, Ceria/Polyoxometalates hybrid (CeONP@POMs) with both proteolytic and superoxide dismutase (SOD) activities. Our results indicated that CeONP@POMs could efficiently degrade Aβ aggregates and reduce intracellular reactive oxygen species (ROS). More importantly, CeONP@POMD could not only promote PC12 cell proliferation and can cross blood-brain barrier (BBB), but also inhibit Aβ-induced BV2 microglial cell activation which was demonstrated by immunoluorescence assay and flow cytometry measurements. In vivo studies further indicated that CeONP@POMD as nanozyme possessed good biocompatibility, evidenced by a detailed study of their biodistribution, body weight change, and in vivo toxicology. Therefore, our results pave the way for design of multifunctional artificial nanozyme for treatment of neurotoxicity of amyloid-β peptide. PMID:27179436

  3. Sensitive bi-enzymatic biosensor based on polyphenoloxidases-gold nanoparticles-chitosan hybrid film-graphene doped carbon paste electrode for carbamates detection.

    Science.gov (United States)

    Oliveira, Thiago M B F; Barroso, M Fátima; Morais, Simone; Araújo, Mariana; Freire, Cristina; de Lima-Neto, Pedro; Correia, Adriana N; Oliveira, Maria B P P; Delerue-Matos, Cristina

    2014-08-01

    A bi-enzymatic biosensor (LACC-TYR-AuNPs-CS/GPE) for carbamates was prepared in a single step by electrodeposition of a hybrid film onto a graphene doped carbon paste electrode (GPE). Graphene and the gold nanoparticles (AuNPs) were morphologically characterized by transmission electron microscopy, X-ray photoelectron spectroscopy, dynamic light scattering and laser Doppler velocimetry. The electrodeposited hybrid film was composed of laccase (LACC), tyrosinase (TYR) and AuNPs entrapped in a chitosan (CS) polymeric matrix. Experimental parameters, namely graphene redox state, AuNPs:CS ratio, enzymes concentration, pH and inhibition time were evaluated. LACC-TYR-AuNPs-CS/GPE exhibited an improved Michaelis-Menten kinetic constant (26.9±0.5M) when compared with LACC-AuNPs-CS/GPE (37.8±0.2M) and TYR-AuNPs-CS/GPE (52.3±0.4M). Using 4-aminophenol as substrate at pH5.5, the device presented wide linear ranges, low detection limits (1.68×10(-9)±1.18×10(-10)-2.15×10(-7)±3.41×10(-9)M), high accuracy, sensitivity (1.13×10(6)±8.11×10(4)-2.19×10(8)±2.51×10(7)%inhibitionM(-1)), repeatability (1.2-5.8% RSD), reproducibility (3.2-6.5% RSD) and stability (ca. twenty days) to determine carbaryl, formetanate hydrochloride, propoxur and ziram in citrus fruits based on their inhibitory capacity on the polyphenoloxidases activity. Recoveries at two fortified levels ranged from 93.8±0.3% (lemon) to 97.8±0.3% (orange). Glucose, citric acid and ascorbic acid do not interfere significantly in the electroanalysis. The proposed electroanalytical procedure can be a promising tool for food safety control. PMID:24642204

  4. 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.

  5. 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

  6. 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

  7. 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

  8. 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.

  9. Influence of Cd2+/S2− molar ratio and of different capping environments in the optical properties of CdS nanoparticles incorporated within a hybrid diureasil matrix

    International Nuclear Information System (INIS)

    Graphical abstract: - Highlights: • Optical properties of the CdS NPs are dependent on the experimental conditions. • Better preservation of original optical properties of NPs when MPTMS is used. • Use of MPTMS is affected by the Cd2+/S2− molar ratio of the CdS NPs. • Cd2+/S2− molar ratio influenced the stability of the CdS NPs within the matrix. • The hybrid intrinsic matrix PL is affected by CdS NPs when MPTMS is used. - Abstract: The incorporation of CdS nanoparticles (NPs), as prepared through colloidal methods using reverse micelles, within diureasil hybrid organic–inorganic sol–gel matrices was investigated. Several experimental conditions, namely the influence of capping agent 3-mercaptopropyltrimethoxysilane (MPTMS) or the use of tetraethoxysilane (TEOS), were studied in order to assure the preservation of the original optical properties of colloidal CdS NPs after the incorporation of the NPs within the solid diureasil hybrid matrix. The diureasil matrix is based on a siliceous network cross linked through urea bonds to poly(oxyethylene)/poly(oxypropylene) (PEO/PPO) chains. The influence of the Cd2+/S2− molar ratio of the NPs in the stability and dispersion of the NPs within the diureasil matrix was also investigated. The obtained CdS doped hybrid matrix was characterized by absorption, steady-state and time-resolved photoluminescence (PL) spectroscopy and by transmission electron microscopy (TEM). The stability of the CdS NPs within the hybrid matrix showed to be dependent on the Cd2+/S2− molar ratio used in the synthesis of the NPs. The use of MPTMS proved to be crucial in the preservation of the original optical properties of the colloidal CdS NPs after the incorporation of the NPs within the hybrid matrix. The effect of MPTMS was in turn influenced by the Cd2+/S2− molar ratio employed in the synthesis of the CdS NPs. The use of MPTMS was less effective when Cd2+/S2− molar ratio equal to 0.5 was used. In the absence of MPTMS or

  10. 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...

  11. 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

  12. 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.

  13. 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. PMID:27070756

  14. 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.

  15. Zinc oxide nanoparticles inside microgel

    Energy Technology Data Exchange (ETDEWEB)

    Agrawal, M.; Zafeiropoulos, N.; Stamm, M. [Leibniz-Inst. fuer Polymerforschung Dresden e.V., Dresden (Germany); Pich, A. [Inst. fuer Makromolekulare Chemie und Textilchemie, Technische Univ. Dresden (Germany)

    2007-07-01

    We investigate on the synthesis of temperature and pH-sensitive hybrid microgels containing ZnO nanoparticles. The synthesis of ZnO nanoparticles was carried out in the presence of poly(N-vinylcaprolactum-co-acetoacetoxyethylmethacrylate-co-N-[3-(dimethylamino)propyl] methacryl amide)(VCL/AAEM/PDMAPMAm) and it was observed that these microgels act as the container for deposition of ZnO nanoparticles, under the specific reaction conditions, leading to the formation of hybrid microgels. A close relationship between changes in properties of microgels and the loaded ZnO content was reported. Microscopic studies confirmed the inclusion of nanoparticles into microgels. It has been found that prepared microgels have tendency to form composite films on solid substrates after water evaporation, with homogenous distribution of ZnO nanoparticles in polymer matrix. (orig.)

  16. An inorganic–organic hybrid material based on ZnO nanoparticles anchored to a composite made from polythiophene and hexagonally ordered silica for use in solid-phase fiber microextraction of PAHs

    International Nuclear Information System (INIS)

    We report on an inorganic–organic hybrid nanocomposite that represents a novel kind of fiber coating for solid-phase microextraction (SPME) of polycyclic aromatic hydrocarbons (PAHs). The material is composed of ZnO nanoparticles, polythiophene and hexagonally ordered silica, and displays good extraction capability due to its nanostructure. The nanocomposite was synthesized by an in-situ polymerization technique, and the ZnO nanoparticles were anchored to the pores in the walls. The ZnO/polythiophene/hexagonally ordered silica (ZnO/PT/SBA-15) nanocomposite was then deposited on a stainless steel wire to obtain the fiber for SPME of PAHs. Optimum conditions include an extraction temperature of 85 °C (for 30 min only), a desorption temperature of 260 °C (for 2 min), and a salt concentration (NaCl) of 20 % (w/v). The detection limits are between 8.2 and 20 pg mL−1, and the linear responses extend from 0.1 to 10 ng mL−1. The repeatability for one fiber (for n = 5), expressed as relative standard deviation, is between 4.3 and 9.1 %. The method offers the advantage of being simple to use, rapid, and low-cost (in terms of equipment). The thermal stability of the fiber and high relative recovery (compared to conventional methods) represent additional attractive features. (author)

  17. Carbon Nanotube Addition to Simultaneously Enhance Strength and Ductility of Hybrid AZ31/AA5083 Alloy

    OpenAIRE

    Muralidharan Paramsothy; Manoj Gupta; Jimmy Chan; Richard Kwok

    2011-01-01

    AZ31/AA5083 hybrid alloy nanocomposite containing CNT nanoparticle reinforcement was fabricated using solidification processing followed by hot extrusion. The AZ31/AA5083 hybrid alloy nanocomposite exhibited similar grain size to monolithic AZ31/AA5083 hybrid alloy, reasonable CNT nanoparticle distribution, non-dominant (0 0 0 2) texture in the longitudinal direction, and 20% higher hardness than monolithic AZ31/AA5083 hybrid alloy. Compared to monolithic AZ31/AA5083 hybrid alloy (in tension)...

  18. 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.

  19. 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

  20. 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

  1. 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.

  2. 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.

  3. Topical delivery of anti-TNFα siRNA and capsaicin via novel lipid-polymer hybrid nanoparticles efficiently inhibits skin inflammation in vivo

    OpenAIRE

    Desai, Pinaki R.; Marepally, Srujan; Patel, Apurva R.; Voshavar, Chandrashekhar; Chaudhuri, Arabinda; Singh, Mandip

    2013-01-01

    The barrier properties of the skin pose a significant but not insurmountable obstacle for development of new effective anti-inflammatory therapies. The objective of this study was to design and evaluate therapeutic efficacy of anti-nociception agent Capsaicin (Cap) and anti-TNFα siRNA (siTNFα) encapsulated cyclic cationic head Lipid-Polymer hybrid Nanocarriers (CyLiPns) against chronic skin inflammatory diseases. Physico-chemical characterizations including hydrodynamic size, surface potentia...

  4. 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.

  5. 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...

  6. 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

  7. Highly sensitive hybridization assay using the electrochemiluminescence of an ITO electrode, CdTe quantum dots functionalized with hierarchical nanoporous PtFe nanoparticles, and magnetic graphene nanosheets

    International Nuclear Information System (INIS)

    We report on a disposable microdevice suitable for sandwich-type electrochemiluminescence (ECL) detection of DNA. The method is making use of CdTe quantum dots functionalized with hierarchical nanoporous PtFe (CdTe-PtFe) nanoparticles and with magnetic graphene nanosheets. The latter were selected as carriers for the capture DNA due to their excellent biomagnetic separation capability and electrical properties. The CdTe-PtFe nanoparticles were used to label the signal DNA which resulted in distinctly enhanced ECL owing to the large specific surface area and good electrical conductivity of the PtFe alloy. A DNA sensor was constructed on a disk-shaped indium tin oxide electrode that was fabricated via etching. Under optimal conditions, the biosensor responds linearly to DNA in the 0.02 fM to 5000 fM concentration range, with a detection limit as low as 15 aM. The electrode is regenerable. The method displays excellent specificity, extremely good sensitivity, and is highly reproducible. (author)

  8. Colloidal thermoresponsive gel forming hybrids.

    Science.gov (United States)

    Liu, Ruixue; Tirelli, Nicola; Cellesi, Francesco; Saunders, Brian R

    2010-09-15

    Colloidal hybrids comprise organic and inorganic components and are attracting considerable attention in the literature. Recently, we reported hybrid anisotropic microsheets that formed thermoresponsive gels in polymer solutions [Liu et al., Langmuir, 25, 490, 2009]. Here, we investigate the composition and properties of these hybrid colloids themselves in detail for the first time. Three different cationic PNIPAm (N-isopropylacrylamide) graft copolymers and two inorganic nanoparticle types (laponite and Ludox silica) were used to prepare a range of hybrids. Anisotropic microsheets only formed when laponite particles were added to the copolymer implying directed self-assembly. Aqueous dispersions of the microsheets spontaneously formed gels at room temperature and these gels were thermoresponsive. They represent a new class of gel forming colloid and are termed thermoresponsive gel forming hybrids. The compositions of the hybrids were determined from thermogravimetric analysis and those that gave gel forming behaviour identified. Variable-temperature rheology experiments showed that the elasticity of the gels increased linearly with temperature. The reversibility of the thermally-triggered changes in gel elasticity was investigated. The concentration dependence of the rheology data was well described by elastic percolation scaling theory and the data could be collapsed onto a master curve. The concentration exponent for the elastic modulus was 2.5. The strong attractive interactions that exist between the dispersed gel forming hybrids was demonstrated by the formation of stable thermoresponsive hybrid hydrogels through casting of hybrid dispersions. PMID:20561633

  9. 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

  10. Fast determination of Ziziphora tenuior L. essential oil by inorganic-organic hybrid material based on ZnO nanoparticles anchored to a composite made from polythiophene and hexagonally ordered silica.

    Science.gov (United States)

    Piryaei, Marzieh; Abolghasemi, Mir Mahdi; Nazemiyeh, Hossein

    2015-01-01

    In this paper, for the first time, an inorganic-organic hybrid material based on ZnO nanoparticles was anchored to a composite made from polythiophene and hexagonally ordered silica (ZnO/PT/SBA-15) for use in solid-phase fibre microextraction (SPME) of medicinal plants. A homemade SPME apparatus was used for the extraction of volatile components of Ziziphora tenuior L. A simplex method was used for optimisation of five different parameters affecting the efficiency of the extraction. The main constituents extracted by ZnO/PT/SBA-15 and PDMS fibres and hydrodistillation (HD) methods, respectively, included pulegone (51.25%, 53.64% and 56.68%), limonene (6.73%, 6.58% and 8.3%), caryophyllene oxide (5.33%, 4.31% and 4.53%) and 1,8-cineole (4.21%, 3.31% and 3.18%). In comparison with the HD method, the proposed technique could equally monitor almost all the components of the sample, in an easier way, in a shorter time and requiring a much lower amount of the sample. PMID:25496469

  11. 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.

  12. 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

  13. 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.

  14. 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.

  15. 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.

  16. Chitosan-guar gum-silver nanoparticles hybrid matrix with immobilized enzymes for fabrication of beta-glucan and glucose sensing photometric flow injection system.

    Science.gov (United States)

    Bagal-Kestwal, Dipali R; Kestwal, Rakesh Mohan; Hsieh, Wen-Ting; Chiang, Been-Huang

    2014-01-01

    Simple and fast photometric flow injection analysis system was developed for sensing of β-1,3-glucan from medicinal mushroom Ganoderma lucidum during fermentation. For this purpose, the chitosan-guar gum-silver nanoparticle-beta glucanase (Ch-GG-AgNPs-βG) beads and Ch-GG-AgNPs-GOD (glucose oxidase) beads were prepared. The bead packed mini-columns were then used to assemble a flow injection analysis (FIA) system for the detection of β-(1→3)-d-glucan biomarker or glucose. This colorimetric flow system can detect glucose and glucan with detection limits as low as 50ngmL(-1) and 100ngmL(-1) (S/N=3), respectively. The analysis time of this FIA was approximately 40s, which is faster than the previously reported glucan sensors. The glucose and glucan calibration curves were obtained in the range of 0.25-1.25μgmL(-1) (R(2)=0.988) and 0.2-1.0μgmL(-1)(R(2)=0.979), respectively. The applicability of the nano-bio-composite FIA sensor system for spiked and real β-(1→3)-d-glucan samples were tested, and the accuracy of the results were greater than 95%. Thus, the designed FIA provides a simple, interference free and rapid tool for monitoring glucose and β-glucan content, which can be used for various food samples with a little modification. PMID:24200877

  17. 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

  18. 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

  19. 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

  20. 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

  1. 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

  2. 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...

  3. 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. PMID:26852753

  4. 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.

  5. 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

  6. Fabrication of Hybrid Nanostructures via Nanoscale Laser-Induced Reshaping for Advanced Light Manipulation.

    Science.gov (United States)

    Zuev, Dmitry A; Makarov, Sergey V; Mukhin, Ivan S; Milichko, Valentin A; Starikov, Sergey V; Morozov, Ivan A; Shishkin, Ivan I; Krasnok, Alexander E; Belov, Pavel A

    2016-04-01

    Ordered hybrid nanostructures for nanophotonics applications are fabricated by a novel approach via femtosecond laser melting of asymmetric metal-dielectric (Au/Si) nanoparticles created by lithographical methods. The approach allows selective reshaping of the metal components of the hybrid nanoparticles without affecting the dielectric ones and is applied for tuning of the scattering properties of the hybrid nanostructures in the visible range. PMID:26901635

  7. 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. PMID:26673736

  8. DNA-directed self-assembly of gold nanoparticles into binary and ternary nanostructures

    Science.gov (United States)

    Yao, Hui; Yi, Changqing; Tzang, Chi-Hung; Zhu, Junjie; Yang, Mengsu

    2007-01-01

    The assembly and characterization of gold nanoparticle-based binary and ternary structures are reported. Two strategies were used to assemble gold nanoparticles into ordered nanoscale architectures: in strategy 1, gold nanoparticles were functionalized with single-strand DNA (ssDNA) first, and then hybridized with complementary ssDNA-labelled nanoparticles to assemble designed architectures. In strategy 2, the designed architectures were constructed through hybridization between complementary ssDNA first, then by assembling gold nanoparticles to the scaffolding through gold-sulfur bonds. Both TEM measurements and agarose gel electrophoresis confirmed that the latter strategy is more efficient in generating the designed nanostructures.

  9. 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.

  10. Hybrid microparticles for drug delivery and magnetic resonance imaging.

    Science.gov (United States)

    Serrano-Ruiz, David; Laurenti, Marco; Ruiz-Cabello, Jesús; López-Cabarcos, Enrique; Rubio-Retama, Jorge

    2013-05-01

    In this work, we report the synthesis, characterization, and possible application as drug-delivery system magnetically triggered, of hybrid microparticles formed by magnetic nanoparticles embedded within poly(ε-caprolactone). The magnetism of the microparticles permits their localization within the body using magnetic resonance imaging, and the biodegradable polymer layer allows entrapping drugs that can be released when temperature increases. The synthesis of the hybrid material was performed using "grafting from" technique of conveniently modified magnetic nanoparticles. Subsequently, the resulting hybrid nanoparticles were assembled into spherical particles of 138 ± 49 nm via precipitation technique. The produced hybrid material was evaluated as stimuli-responsive drug delivery system in which the release of the drug was triggered by magnetic induction. Furthermore, the microparticles were injected in rats and their localization within the animal was monitored using the local field inhomogeneities generated by the particles. PMID:22915497

  11. Local energy transfer in hybrid nanoplasmonics

    Science.gov (United States)

    Bachelot, Renaud; Zhou, Xuan; Plain, Jérome; Adam, Pierre-Michel; Baudrion, Anne-Laure; Gray, Stephen K.; Wiederrecht, Gary P.

    2014-05-01

    Incorporating resonant optical properties of metal nanostructures into nanoscale applications such as ultrahigh density storage devices, nanoelectronics, and nanophotonics has gained considerable interest within the last years. Recent advances in hybrid and molecular plasmonics are presented. The approach relies on near-field energy transfer between metal nanoparticles and other molecular material, and is not diffraction-limited. We will see that optical nanosources supported by metal nanoparticles can be used for controlling/triggering photochemical and photo physical processes involving photons, charges and motion transfers at the nanoscale. In particular, three examples will be presented and commented: free radical photopolymerization, photo isomerization and nanoscale strong coupling. These examples open new routes including optical near-field photography of ultra confined fields, mode hybridizing in single nanoparticles, molecular optical nanomotors, and new anisotropic nanoemitters.

  12. 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...

  13. 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

  14. 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...

  15. 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.

  16. 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)

  17. 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.

  18. Multifunctional Chitosan-Copper Oxide Hybrid Material: Photocatalytic and Antibacterial Activities

    OpenAIRE

    Yuvaraj Haldorai; Jae-Jin Shim

    2013-01-01

    Chitosan (CS) anchored copper oxide (CuO) hybrid material was prepared by chemical precipitation method. Fourier transform infrared spectroscopy (FT-IR) and X-ray diffraction (XRD) confirmed the formation of CS-CuO hybrid. Transmission electron microscopy (TEM) analysis showed the immobilization of CuO nanoparticles on the surface of CS. The hybrid was also characterized by thermogravimetric analysis (TGA) and zeta potential. The hybrid exhibited high photocatalytic activity as evident from t...

  19. 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.

  20. 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.

  1. 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...

  2. Flare Hybrids

    OpenAIRE

    M. Tomczak; Dubieniecki, P.

    2015-01-01

    Svestka (Solar Phys. 1989, 121, 399) on the basis of the Solar Maximum Mission observations introduced a new class of flares, the so-called flare hybrids. When they start, they look as typical compact flares (phase 1), but later on they look like flares with arcades of magnetic loops (phase 2). We summarize the features of flare hybrids in soft and hard X-rays as well as in extreme-ultraviolet; these allow us to distinguish them from other flares. Additional energy release or long plasma cool...

  3. 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.

  4. 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...

  5. 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...

  6. 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

  7. 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.

  8. 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.

  9. Hybrid nanostructures for high-sensitivity luminescence nanothermometry in the second biological window.

    Science.gov (United States)

    Cerón, Elizabeth Navarro; Ortgies, Dirk H; Del Rosal, Blanca; Ren, Fuqiang; Benayas, Antonio; Vetrone, Fiorenzo; Ma, Dongling; Sanz-Rodríguez, Francisco; Solé, José García; Jaque, Daniel; Rodríguez, Emma Martín

    2015-08-26

    Hybrid nanostructures containing neodymium-doped nanoparticles and infrared-emitting quantum dots constitute highly sensitive luminescent thermometers operating in the second biological window. They demonstrate that accurate subtissue fluorescence thermal sensing is possible. PMID:26174612

  10. 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

  11. 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...

  12. 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.

  13. In Situ Synthesis of Bimetallic Hybrid Nanocatalysts on a Paper-Structured Matrix for Catalytic Applications

    OpenAIRE

    Hirotaka Koga; Takuya Kitaoka; Yuuka Umemura

    2011-01-01

    Bimetallic nanoparticles have attracted significant attention as their electrochemical and catalytic properties being superior to those of the individual component nanoparticles. In this study, gold-silver hybrid nanoparticles (AuAgNPs) with an Aucore-Agshell nanostructure were successfully synthesized on zinc oxide (ZnO) whiskers. The as-prepared nanocatalyst, denoted AuAgNPs@ZnO whisker, exhibits an excellent catalytic efficiency in the aqueous reduction of 4-nitrophenol to 4-aminophenol; t...

  14. 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...

  15. Hybrid Gear

    Science.gov (United States)

    Handschuh, Robert F. (Inventor); Roberts, Gary D. (Inventor)

    2016-01-01

    A hybrid gear consisting of metallic outer rim with gear teeth and metallic hub in combination with a composite lay up between the shaft interface (hub) and gear tooth rim is described. The composite lay-up lightens the gear member while having similar torque carrying capability and it attenuates the impact loading driven noise/vibration that is typical in gear systems. The gear has the same operational capability with respect to shaft speed, torque, and temperature as an all-metallic gear as used in aerospace gear design.

  16. DNA-scaffolded nanoparticle structures

    Energy Technology Data Exchange (ETDEWEB)

    Hoegberg, Bjoern; Olin, Haakan [Department of Engineering Physics and Mathematics, Mid Sweden University, SE-851 70 Sundsvall, Sweden (Sweden)

    2007-03-15

    DNA self-assembly is a powerful route to the production of very small, complex structures. When used in combination with nanoparticles it is likely to become a key technology in the production of nanoelectronics in the future. Previously, demonstrated nanoparticle assemblies have mainly been periodic and highly symmetric arrays, unsuited as building blocks for any complex circuits. With the invention of DNA-scaffolded origami reported earlier this year (Rothemund P W K 2006 Nature 440 (7082) 297-302), a new route to complex nanostructures using DNA has been opened. Here, we give a short review of the field and present the current status of our experiments were DNA origami is used in conjunction with nanoparticles. Gold nanoparticles are functionalized with thiolated single stranded DNA. Strands that are complementary to the gold particle strands can be positioned on the self-assembled DNA-structure in arbitrary patterns. This property should allow an accurate positioning of the particles by letting them hybridize on the lattice. We report on our recent experiments on this system and discuss open problems and future applications.

  17. 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.

  18. 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.

  19. Biopolymeric nanoparticles

    International Nuclear Information System (INIS)

    This review on nanoparticles highlights the various biopolymers (proteins and polysaccharides) which have recently revolutionized the world of biocompatible a