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Sample records for silica-coated fe3o4 nanoparticles

  1. Investigation of synthesized silica coating Fe3O4 nanoparticles efficiency in removal of NOM from water

    Directory of Open Access Journals (Sweden)

    E. Karimi pasandideh

    2014-05-01

    Conclusion: Having high number of active surface sites, magnetic properties, easily separation using magnetic field, and its cost-effectiveness, the Fe3O4/SiO2 nanoparticles could be used as an efficient adsorbent in removal of humic acid from water.

  2. Magnetic, Fluorescence and Transition Metal Ion Response Properties of 2,6-Diaminopyridine Modified Silica-Coated Fe3O4 Nanoparticles

    Directory of Open Access Journals (Sweden)

    Yunhui Zhai

    2016-08-01

    Full Text Available Multi-functional nanoparticles possessing magnetic, fluorescence and transition metal ion response properties were prepared and characterized. The particles have a core/shell structure that consists of silica-coated magnetic Fe3O4 and 2,6-diaminopyridine anchored on the silica surface via organic linker molecules. The resultant nanoparticles were found by transmission electron microscopy to be well-dispersed spherical particles with an average diameter of 10–12 nm. X-ray diffraction analysis suggested the existence of Fe3O4 and silica in/on the particle. Fourier transform infrared spectra revealed that 2,6-diaminopyridine molecules were successfully covalently bonded to the surface of magnetic composite nanoparticles. The prepared particles possessed an emission peak at 364 nm with an excitation wavelength of 307 nm and have a strong reversible response property for some transition metal ions such as Cu2+ and Zn2+. This new material holds considerable promise in selective magneto separation and optical determination applications.

  3. Investigation of synthesized silica coating Fe3O4 nanoparticles efficiency in removal of NOM from water

    OpenAIRE

    E. Karimi pasandideh; R Rezaei Kalantary; S. Nasseri; A. H. Mahvi; R Nabizadeh; A Esrafili

    2014-01-01

    Background and Objective: The presence of natural organic materials (NOM) in water resources affects its quality (i.e. color, odor, and taste). In addition, it leads to the fouling of filters and membranes and reduces water treatment efficiency during flocculation/ coagulation. Moreover, NOM reacts with disinfectants and produces byproducts (DBPs), which are harmful to human health. Magnetic nanoparticles have been reported as effective adsorbents for the removal of pollutants from the aqueou...

  4. Fe3O4@polydopamine Composite Theranostic Superparticles Employing Preassembled Fe3O4 Nanoparticles as the Core.

    Science.gov (United States)

    Ge, Rui; Li, Xing; Lin, Min; Wang, Dandan; Li, Shuyao; Liu, Shuwei; Tang, Qi; Liu, Yi; Jiang, Jinlan; Liu, Lidi; Sun, Hongchen; Zhang, Hao; Yang, Bai

    2016-09-01

    Iron oxide (Fe3O4), polydopamine (PDA), and in particular their composites are examples of the safest nanomaterials for developing multifunctional nanodevices to perform noninvasive tumor diagnosis and therapy. However, the structures and performances of Fe3O4-PDA nanocomposites should be further perfected to enhance the theranostic efficiency. In this work, we demonstrate the fabrication of PDA-capped Fe3O4 (Fe3O4@PDA) superparticles (SPs) employing preassembled Fe3O4 nanoparticles (NPs) as the cores. Owing to the collective effect of preassembled Fe3O4 NPs, the superparamagnetism and photothermal performance of Fe3O4@PDA SPs are greatly enhanced, thus producing nanodevices with improved magnetic resonance imaging (MRI)-guided photothermal efficiency. Systematical studies reveal that the molar extinction coefficient of the as-assembled Fe3O4 SPs is 3 orders of magnitude higher than that of individual Fe3O4 NPs. Also due to the high aggregation degree of Fe3O4 NPs, the T2-weighted MRI contrast is greatly enhanced for the SPs with r2 relaxivity of 230.5 mM(-1) s(-1), which is ∼2.5 times larger than that of individual Fe3O4 NPs. The photothermal stability, physiological stability, and biocompatibility, as well as the photothermal performance of Fe3O4 SPs, are further improved by enveloping with PDA shell.

  5. 磁性Fe3O4纳米颗粒%Fe3O4 Magnetic Nanoparticle

    Institute of Scientific and Technical Information of China (English)

    赵朝辉; 姚素薇; 张卫国

    2005-01-01

      介绍了机械球磨法、水热法、微乳液法、超声沉淀法、水解法制备磁性纳米Fe3O4颗粒的工艺,归纳了各种制备方法的特点。针对当前纳米 Fe3O4颗粒的两大研究热点⎯⎯Fe3O4复合纳米颗粒和磁流体进行了综述,并展望了Fe3O4纳米颗粒的研究前景。%  Various preparation methods of Fe3O4 nanoparticle, such as mechanical milling, hydrothermal method, micro-emulsion method, sonochemical synthesis and hydrolytic method, are introduced, and the characteristics of these methods are summarized. Brief introduction is also given to the Fe3O4 composite material and magneto-fluid, which are two recent focusing fields on Fe3O4 nanoparticle research. Furthermore, research prospect of Fe3O4 nanoparticle is presented.

  6. Synthesis of Fe3O4@SiO2@polymer nanoparticles for controlled drug release

    Institute of Scientific and Technical Information of China (English)

    2010-01-01

    Novel multifunctional nanoparticles containing a magnetic Fe3O4@SiO2 sphere and a biocompatible block copolymer poly(ethylene glycol)-b-poly(aspartate)(PEG-b-PAsp) were prepared.The silica coated on the superparamagnetic core was able to achieve a magnetic dispersivity,as well as to protect Fe3O4 against oxidation and acid corrosion.The PAsp block was grafted to the surface of Fe3O4@SiO2 nanoparticles by amido bonds,and the PEG block formed the outermost shell.The anticancer agent doxorubicin(DOX) was loaded into the hybrid nanoparticles via an electrostatic interaction between DOX and PAsp.The release rate of DOX could be adjusted by the pH value.

  7. Surface Modfication of Fe3O4 Nanoparticles

    Institute of Scientific and Technical Information of China (English)

    LIU Yong-jian; JIA Hong-yi; ZHUANG Hong

    2006-01-01

    Nanometer particles are important portion of magnetic fluid. Fe3O4 magnetic nanoparticles were studied in this paper and the surface modification of Fe3O4 nanoparticles was investigated by a series of experiments. Fe3O4 magnetic nanoparticles were synthesized with pH value, temperature, and the dosage of surfactant. The phase, structure, size and magnetism of nanoparticles were tested by X-ray diffration (XRD), transmission electron microscopy (TEM) and magnetic balance. On the basis of the surface modification coating mechanism, the experimental phenomena and the effects on the variation of size, magnetism and stability of Fe3O4 nanoparticles were theoretically analyzed. X-Ray diffraction spectrum and TEM photograph show that 1) the nanoparticles structure is perfect, 2) the diameter of namoparticles is small and have good deliquescence, and 3) Sodium oleate is the anion surfactant. Therefore 1) the good condition of surface modification is in an acidic solution, 2) the best temperature of surface modification is at 80 ℃, and 3) the dosage of surfactant should be about 0.6 times of that of Fe2+.

  8. Solvothermal synthesis of magnetic Fe3O4 microparticles via self-assembly of Fe3O4 nanoparticles

    Institute of Scientific and Technical Information of China (English)

    Wei Zhang; Fenglei Shen; Ruoyu Hong

    2011-01-01

    Ferromagnetic Fe3O4 nanoparticles were synthesized and then self-assembled into microparticles via a solvothermal method, using FeCI3.6H2O as the iron source, sodium oleate as the surfactant, and ethylene glycol as the reducing agent and solvent. The obtained Fe3O4 microparticles were characterized by X-ray powder diffraction (XRD), X-ray photoelectron spectroscopy (XPS), Raman spectroscopy and vibrating sample magnetometer (VSM). The size and morphology of the particles were examined using transmission electron microscopy (TEM) and scanning electron microscopy (SEM). The Fe3O4 microparticles of nearly monodisperse diameters, controllable in the range of 120-400 nm, consist of assemblies of Fe3O4nanoparticles with a diameter of 22 nm. The effects of reaction time, amount of surfactant and NaAc on the products were discussed. Interestingly, by using the pre-synthesized Fe3O4 microparticles as the growth substrates, spherical and smooth-looking Fe3O4 microparticles with average diameter of lμmwere obtained. A plausible formation process was discussed.

  9. Facile synthesis of superparamagnetic Fe3O4@Au nanoparticles for photothermal destruction of cancer cells.

    Science.gov (United States)

    Ren, Jinfeng; Shen, Shun; Pang, Zhiqing; Lu, Xiaohui; Deng, Chunhui; Jiang, Xinguo

    2011-11-14

    Superparamagnetic Fe(3)O(4) nanoparticles with positive surface ξ-potential were synthesized via a solvothermal route. After Fe(3)O(4) was mixed with HAuCl(4) and NaBH(4), the reduced Au nanoparticles could be directly adsorbed onto the surface of Fe(3)O(4) nanoparticles. The as-synthesized nanocomposites were successfully applied to photothermal destruction of cancer cells. PMID:21952492

  10. Polyethyleneimine-modified superparamagnetic Fe3O4 nanoparticles for lipase immobilization: Characterization and application

    International Nuclear Information System (INIS)

    Magnetically separable nanospheres consisting of polyethyleneimine (PEI) and succinated PEI grafted on silica coated magnetite (Fe3O4) were prepared and characterized using Fourier transform infrared spectroscopy, thermogravimetric analysis, X-ray diffraction, vibrating sample magnetometer, scanning electron microscopy and transmission electron microscopy. The prepared magnetic nanoparticles were then applied for physical adsorption or covalent attachment of Thermomyces lanuginosa lipase (TLL) via glutaraldehyde or hexamethylene diisocyanate. The reusability, storage, pH and thermal stabilities of the immobilized enzymes compared to that of free lipase were examined. The obtained results showed that the immobilized lipase on MNPs@PEI-GLU was the best biocatalyst which retained 80% of its initial activity after 12 cycles of application. The immobilized lipase on the selected support (MNPs@PEI-GLU) was also applied for the synthesis of ethyl valerate. Following 24 h incubation of the immobilized lipase on the selected support in n-hexane and solvent free media, the esterification percentages were 72.9% and 28.9%, respectively. - Graphical abstract: A schematic of the preparation of PEI- and succinated PEI-grafted Fe3O4 MNPs (MNPs@PEI) and the immobilization of lipase by covalent bonding and adsorption. - Highlights: • Functionalized polyethylenimine-grafted magnetic nanoparticles were synthesized. • The prepared supports were fully characterized by various analysis methods. • Lipase was immobilized on the nanostructures by adsorption and covalent attachment. • Immobilized lipase produced ethyl valerate in solvent free medium

  11. CHARACTERIZATION OF MANGANESE PHTHALOCYANINE-Fe3O4 NANOPARTICLE COMPOSITE AND ITS ELECTROMAGNETORHEOLOGICAL FLUID

    Institute of Scientific and Technical Information of China (English)

    1999-01-01

    Manganese phthalocyanine (MnPc)-Fe3O4 nanoparticles composite was prepared and characterized. The results show that MnPc are complexed on the surface of Fe3O4 nanoparticles in the state of single molecule. There is effective composite between MnPc and Fe3O4 nanoparticles which can improve the antioxidization ability of Fe3O4 nanoparticles greatly. The composite was dispersed into chlorinated paraffin oil to form electromagnetorheological (EMR) fluid with high activity,and the EMR properties of this EMR fluid are studied.

  12. Magnetite Fe3O4 nanoparticles synthesis by wet chemical reduction and their characterization

    Science.gov (United States)

    Chaki, S. H.; Malek, Tasmira J.; Chaudhary, M. D.; Tailor, J. P.; Deshpande, M. P.

    2015-09-01

    The authors report the synthesis of Fe3O4 nanoparticles by wet chemical reduction technique at ambient temperature and its characterization. Ferric chloride hexa-hydrate (FeCl3 · 6H2O) and sodium boro-hydrate (NaBH4) were used for synthesis of Fe3O4 nanoparticles at ambient temperature. The elemental composition of the synthesized Fe3O4 nanoparticles was determined by energy dispersive analysis of x-rays technique. The x-ray diffraction (XRD) technique was used for structural characterization of the nanoparticles. The crystallite size of the nanoparticles was determined using XRD data employing Scherrer’s formula and Hall-Williamson’s plot. Surface morphology of as-synthesized Fe3O4 nanoparticles was studied by scanning electron microscopy. High resolution transmission electron microscopy analysis of the as-synthesized Fe3O4 nanoparticles showed narrow range of particles size distribution. The optical absorption of the synthesized Fe3O4 nanoparticles was studied by UV-vis-NIR spectroscopy. The as-synthesized nanoparticles were analyzed by Fourier transform infrared spectroscopy technique for absorption band study in the infrared region. The magnetic properties of the as-synthesized Fe3O4 nanoparticles were evaluated by vibrating sample magnetometer technique. The thermal stability of the as-synthesized Fe3O4 nanoparticles was studied by thermogravimetric technique. The obtained results are elaborated and discussed in details in this paper.

  13. Synthesis, characterization and magnetorheological study of 3-aminopropyltriethoxysilane-modified Fe3O4 nanoparticles

    Science.gov (United States)

    Wang, Guangshuo; Ma, Yingying; Tong, Yu; Dong, Xufeng

    2016-03-01

    In this study, monodisperse Fe3O4 nanoparticles were synthesized successfully using a sonochemical method in the presence of 3-aminopropyltriethoxysilane (APTES). The morphology, microstructure and magnetic properties of the bare Fe3O4 and APTES-coated Fe3O4 were investigated in detail by TEM, XRD, FTIR and SQUID. It was found that APTES-coated Fe3O4 showed relatively good dispersion with a narrow size distribution of 8.4 ± 2.1 nm diameter. The functionalization of Fe3O4 was proved to be covalent linking between Fe3O4 and APTES. The field-dependent magnetization curve indicated superparamagnetic behavior of Fe3O4-APTES with a saturation magnetization (M s) of 70.5 emu g-1 at room temperature. A magnetorheological (MR) fluid was prepared using the obtained Fe3O4-APTES nanoparticles with 25 wt% particles, and its MR properties were tested using a Physica MCR301 rheometer fitted with an MRmodule. The results showed that the as-prepared APTES-coated Fe3O4 nanoparticle-based MR fluid exhibited typical MR effects, with increasing viscosity, shear stress and yield stress depending on the applied magnetic field strength.

  14. Hydrothermal synthesis, off-axis electron holography and magnetic properties of Fe3O4 nanoparticles

    DEFF Research Database (Denmark)

    Almeida, Trevor P.; Muxworthy, Adrian R.; Williams, Wyn;

    2014-01-01

    The hydrothermal synthesis of Fe3O4 nanoparticles (NPs) (<50 nm) from mixed FeCl3 / FeCl2 precursor solution at pH ~ 12 has been confirmed using complementary characterisation techniques of transmission electron microscopy and X-ray diffractometry. Off-axis electron holography allowed for visuali......The hydrothermal synthesis of Fe3O4 nanoparticles (NPs) (

  15. Study on the Properties of Metallophthalocyanine-Fe3O4 Nanoparticles Composite

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    The solubility,antioxidation ability,thermal stability,coercivity Hc and long term stability of MPc-Fe3O4-nanoparticles composite(M=Co,Cu,Ni,Mn) have been studied.The results show that MPc-Fe3O4 nanoparticles composite can be easily dissolved in dilute acid.The dissolving rate of different MPc-Fe3O4 nanoparticles composite is in the following order:M=Mn~M=Co<M=Cu<M=Ni.The antioxidation ability of Fe3O4 nanoparticles are improved greatly after their complex with MPc and there is good relationship between Toxidation of Fe3O4 nanoparticles and n ,the complex layers of MPc on the surface of the composite.The results also show that the thermal stability of Fe3O4 nanoparticles increases greatly and the Hc of them decreases dramatically after Fe3O4 nanoparticles form nanoscale composite with MPc.MPc-Fe3O4 nanoparticles composite have high long term stability.

  16. Preparation and characterization of magnetic Fe3O4-chitosan nanoparticles loaded with isoniazid

    Science.gov (United States)

    Qin, H.; Wang, C. M.; Dong, Q. Q.; Zhang, L.; Zhang, X.; Ma, Z. Y.; Han, Q. R.

    2015-05-01

    A novel and simple method has been proposed to prepare magnetic Fe3O4-chitosan nanoparticles loaded with isoniazid (Fe3O4/CS/INH nanocomposites). Efforts have been made to develop isoniazid (INH) loaded chitosan (CS) nanoparticles by ionic gelation of chitosan with tripolyphosphate (TPP). The factors that influence the preparation of chitosan nanoparticles, including the TPP concentration, the chitosan/TPP weight ratio and the chitosan concentration on loading capacity and encapsulation efficiency of chitosan nanoparticles were studied. The magnetic Fe3O4 nanoparticles were prepared by co-precipitation method of Fe2+ and Fe3+. Then the magnetic Fe3O4/CS/INH nanocomposites were prepared by ionic gelation method. The magnetic Fe3O4 nanoparticles and magnetic Fe3O4/CS/INH nanocomposites were characterized by XRD, TEM, FTIR and SQUID magnetometry. The in vitro release of Fe3O4/CS/INH nanocomposites showed an initial burst release in the first 10 h, followed by a more gradual and sustained release for 48 h. It is suggested that the magnetic Fe3O4/CS/INH nanocomposites may be exploited as potential drug carriers for controlled-release applications in magnetic targeted drugs delivery system.

  17. Preparation and characterization of magnetic Fe3O4–chitosan nanoparticles loaded with isoniazid

    International Nuclear Information System (INIS)

    A novel and simple method has been proposed to prepare magnetic Fe3O4–chitosan nanoparticles loaded with isoniazid (Fe3O4/CS/INH nanocomposites). Efforts have been made to develop isoniazid (INH) loaded chitosan (CS) nanoparticles by ionic gelation of chitosan with tripolyphosphate (TPP). The factors that influence the preparation of chitosan nanoparticles, including the TPP concentration, the chitosan/TPP weight ratio and the chitosan concentration on loading capacity and encapsulation efficiency of chitosan nanoparticles were studied. The magnetic Fe3O4 nanoparticles were prepared by co-precipitation method of Fe2+ and Fe3+. Then the magnetic Fe3O4/CS/INH nanocomposites were prepared by ionic gelation method. The magnetic Fe3O4 nanoparticles and magnetic Fe3O4/CS/INH nanocomposites were characterized by XRD, TEM, FTIR and SQUID magnetometry. The in vitro release of Fe3O4/CS/INH nanocomposites showed an initial burst release in the first 10 h, followed by a more gradual and sustained release for 48 h. It is suggested that the magnetic Fe3O4/CS/INH nanocomposites may be exploited as potential drug carriers for controlled-release applications in magnetic targeted drugs delivery system. - Highlights: • A novel and simple method for preparation of nanocomposites for biomedicine. • All the materials are non-toxic and biocompatibility. • This paper gives systematic study of the nanocomposites in biomedicine

  18. Surface organic modification of Fe3O4 nanoparticles by silane-coupling agents

    Institute of Scientific and Technical Information of China (English)

    CUI Sheng; SHEN Xiaodong; LIN Benlan

    2006-01-01

    Fe3O4 nanoparticles were prepared by chemistry co-precipitation and the mean crystal size was 17.9 nm measured by XRD. After it had been treated by silane-coupling agents KH570, magnetic micro-spheres dispersed in organic medium glycol were gained and the mean size of Fe3O4 nanopowders was 33.7 nm . So it can be concluded that magnetic micro-sphere is made of a few Fe3O4 crystals. Many factors of modification were researched, such as the time of ball milling, the content of Fe3O4 and the content of KH570. The modification of Fe3O4 is relative to the time of ball milling, but the dominant function is affected by the content of Fe3O4 and KH570. When the content of Fe3O4 is known, there is a suitable content of KH570. Different content of Fe3O4 will make the different suitable content of KH570, but the range of latter is less than former, which is relative to the distribution of KH570 on Fe3O4 surface or in the solution .

  19. Biomimetic Mussel Adhesive Inspired Clickable Anchors Applied to the Functionalization of Fe3O4 Nanoparticles

    NARCIS (Netherlands)

    Goldmann, Anja S.; Schoedel, Christine; Walther, Andreas; Yuan, Jiayin; Loos, Katja; Mueller, Axel H. E.; Müller, Axel H.E.

    2010-01-01

    The functionalization of magnetite (Fe3O4) nanoparticles with dopamine-derived clickable biomimetic anchors is reported. Herein, an alkyne-modified catechol-derivative is employed as the anchor, as i) the catechol-functional anchor groups possess irreversible covalent binding affinity to Fe3O4 nanop

  20. Radiation preparation and properties of Fe3O4-chitosan magnetic nanoparticles

    International Nuclear Information System (INIS)

    Fe3O4 nanoparticles were dispersed in paraffin and mixed with chitosan by various ratios into homogenous solutions, then gamma irradiated at dose of 40 kGy for preparation of Fe3O4-chitosan nanoparticles. The resulting Fe3O4-chitosan materials were characterized by transmission electron microscopy (TEM), vibrating sample magnetization (VMS) and X-ray diffraction (XRD). Average diameter of obtained nanoparticles increased, whereas its saturated magnetization reduced with chitosan ratio in the solution. The Fe3O4-chitosan nanoparticles obtained from the 5:1 Fe3O4/chitosan admixture were used as absorbents for removal of lead ions (Pb(II)) in aqueous solutions. The results revealed that adsorption capacity depended on the initial amount of Fe3O4-chitosan nanoparticles, and their maximum adsorption capacity for Pb(CH3COO)2.3H2O was 41.4 mg/g at ambient conditions. These results suggested that Fe3O4-chitosan nanoparticles can be applied as a promising adsorbent for removal of heavy metals from contaminated solutions in practice. (author)

  1. Preparation and enhanced properties of Fe3O4 nanoparticles reinforced polyimide nanocomposites

    Science.gov (United States)

    Ding, Daowei; Yan, Xingru; Zhang, Xi; He, Qingliang; Qiu, Bin; Jiang, Dawei; Wei, Huige; Guo, Jiang; Umar, Ahmad; Sun, Luyi; Wang, Qiang; Khan, Mojammel A.; Young, David P.; Zhang, Xin; Weeks, Brandon; Ho, Thomas C.; Guo, Zhanhu; Wei, Suying

    2015-09-01

    Polyimide (PI) nanocomposite reinforced with Fe3O4 nanoparticles (NPs) at various NPs loadings levels of 5.0, 10.0, 15.0, and 20.0 wt% were prepared. The chemical interactions of the Fe3O4 NPs/PI nanocomposites were characterized using Fourier Transform Infrared (FT-IR) spectroscopy. X-ray Diffraction (XRD) results revealed that the addition of NPs had a significant effect on the crystallization of PI. Scanning electron microscope (SEM) and the atomic force microscope (AFM) were used to characterize the dispersion and surface morphology of the Fe3O4 NPs and the PI nanocomposites. The obtained optical band gap of the nanocomposites characterized using Ultraviolet-Visible Diffuse Reflectance Spectroscopy (UV-Vis DRS) was decreased with increasing the Fe3O4 loading. Differential scanning calorimetry (DSC) results showed a continuous increase of Tg with increasing the Fe3O4 NPs loading. Some differences were observed in the onset decomposition temperature between the pure PI and nanocomposites since the NPs and the PI matrix were physically entangled together to form the nanocomposites. The contact angle of pure PI was larger than that of Fe3O4/PI nanocomposites films, and increased with increasing the loading of Fe3O4. The degree of swelling was increased with increasing the Fe3O4 loading and the swelling time. The dielectric properties of the nanocomposite were strongly related to the Fe3O4 loading levels. The Fe3O4/PI magnetic property also had been improved with increasing the loading of the magnetic nanoparticles.

  2. Characteristics of magnetic Fe3O4 nanoparticles encapsulated with human serum albumin

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    Magnetic nanoparticles (Fe3O4) were prepared by chemical precipitation method using Fe2+ and Fe3+salts with sodium hydroxide in the nitrogen atmosphere. Fe3O4 nanoparticles were coated with human serum albumin(HSA) for magnetic resonance imaging as contrast agent. Characteristics of magnetic particles coated or uncoated were carried out using scanning electron microscopy and X-ray diffraction. Zeta potentials, package effects and distributions of colloid particles were measured to confirm the attachment of HSA on magnetic particles. Effects of Fe3O4 nanoparticles coated with HSA on magnetic resonance imaging were investigated with rats. The experimental results show that the adsorption of HSA on magnetic particles is very favorable to dispersing of magnetic Fe3O4 particles, while the sizes of Fe3O4 particles coated are related to the molar ratio of Fe3O4 to HSA. The diameters of the majority of particles coated are less than 100 nm. Fe3O4 nanoparticle coated with HSA has a good biocompatibility and low toxicity. This new contrast agent has some effects on the nuclear magnetic resonance imaging of liver and the lowest dosage is 20 μmol/kg for the demands of diagnosis.

  3. Size-dependent peroxidase-like catalytic activity of Fe3O4 nanoparticles

    Institute of Scientific and Technical Information of China (English)

    Fang Fang Peng; Yu Zhang; Ning Gu

    2008-01-01

    Peroxidase-like catalytic properties of Fe3O4 nanoparticles (NPs) with three different sizes, synthesized by chemical coprecipitation and sol-gel methods, were investigated by UV-vis spectrum analysis. By comparing Fe3O4 NPs with average diameters of 11,20, and 150 nm, we found that the catalytic activity increases with the reduced nanoparticle size. The electrochemical method to characterize the catalytic activity of Fe3O4 NPs using the response currents of the reaction product and substrate was also developed.

  4. A Facile Solvothermal Synthesis of Octahedral Fe3O4 Nanoparticles

    Energy Technology Data Exchange (ETDEWEB)

    Ooi, Frances; DuChene, Joseph S.; Qiu, Jianqing; Graham, Jeremy O.; Engelhard, Mark H.; Cao, Guixin; Gai, Zheng; Wei, Wei

    2015-06-01

    Magnetic nanoparticles are of great technological interest because they promise numerous potential opportunities in biomedicine and data storage. Although intriguing, these applications require exquisite control over nanostructure morphology in order to appropriately harness their magnetic properties. Most synthesis strategies reported to date are unable to routinely produce anisotropic Fe3O4 nanostructures with appropriate sizes to enable integration into biological systems. Here, we report a simple solvothermal synthesis for obtaining octahedral Fe3O4 nanoparticles with suitable sizes for cellular internalization. Furthermore, these ferromagnetic Fe3O4 octahedrons exhibit substantial saturation magnetization with minimal remanence, suggesting their potential applicability for a host of biomedical applications.

  5. Assembly of Fe3O4 nanoparticles on SiO2 monodisperse spheres

    Indian Academy of Sciences (India)

    K C Barick; D Bahadur

    2006-11-01

    The assembly of superparamagnetic Fe3O4 nanoparticles on submicroscopic SiO2 spheres have been prepared by an in situ reaction using different molar ratios of Fe3+/Fe2+ (50–200%). It has been observed that morphology of the assembly and properties of these hybrid materials composed of SiO2 as core and Fe3O4 nanoparticles as shell depend on the molar ratio of Fe3+/Fe2+.

  6. PREPARATION,COMPLEX MECHANISM AND STRUCTURE MODEL OF METALLOPHTHALOC- YANINE-Fe3O4 NANOPARTICLES COMPOSITE

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    MPc-Fe3O4-nanoparticles composite(M=Co, Cu, Ni, Mn) have been prepared and the factors that influence their mean size have been studied. The mean size of the nanoparticles composite increase with the increase of complex temperature. The interaction of MPc with Fe3O4 nanoparticles has been studied. There are M-O covalent bonding and ionic bonding between MPc and Fe3O4 nanoparticles. The intensities of M-O bonding and ionic bonding are in vestigated .The complex mechanism of MPc with Fe3O4 nanoparticles have been studied. First, there are complex between MPc and all Fe3O4 nanoparticles. Then, Fe3O4 nanoparticles accumulate together to form the accumulators, MPc have the function of cohering Fe3O4 nanoparticles. A considerable number of MPc combine with Fe3O4 nanoparticles on the surface of the accumulators to form MPc-Fe3O4 nanoparticles composite. All the above proesses take place spontaneously. The structure model of MPc-Fe3O4 nanoparticles composite has also been investigated. Inside the MPc-Fe3O4 nanoparticles composite, Fe3O4 nanoparticles accumulate together without order, on the surface of the composite, MPc form molecular dispersion layer. The threshold of molecular dispersion layer are also investigated.

  7. 磁性纳米粒子Fe3O4@Au和Fe3O4@Ag的制备及表征%Synthesis and Characterization of Magnetic Fe3O4@Au and Fe3O4 @Ag Nanoparticles

    Institute of Scientific and Technical Information of China (English)

    庄严; 周群; 周全法

    2011-01-01

    利用化学共沉淀法将铁盐和亚铁盐溶液按一定比例混合制备磁性纳米Fe3O4,再用3-巯基丙基三甲氧基硅烷修饰磁性粒子,连接金、银纳米粒子制备了核壳结构的功能性微粒.通过X-射线粉末衍射(XRD)、透射电子显微镜(TEM)及紫外-可见光吸收光谱仪(UV - Vis)对粒子的结构与性质进行表征.结果表明:磁性Fe3O4纳米粒子属立方晶型,Fe3O4@Au和Fe3O4@Ag粒子包裹完全,形状趋近于球形,兼有磁性和金、银纳米粒子的特性,对硝基化合物具有良好的催化性能.%Magnetic nanoparticles of Fe3O4 were prepared by co - deposition. Fe3O4 and gold/silver nano-particles were conjoined with (3 - mercapto - propyl) trimethoxysilane, and then core - shell functional Fe3O4@ Au and Fe3O4@ Ag nanoparticles were prepared by multi - step reduction with sodiumcitrate. These particles were characterized by TEM, XRD, UV - Vis. The analysis results showed that the prepared Fe3O4 nanoparticles are cubic structure. Spherical Fe3O4@ Au and Fe3O4@ Ag nanoparticles have excellent catalytic activity for the reduction of nitrocompounds by borohydride.

  8. Inductive heat property of Fe3O4 nanoparticles in AC magnetic field for local hyperthermia

    Institute of Scientific and Technical Information of China (English)

    ZHAO Donglin; ZENG Xianwei; XIA Qisheng; TANG Jintian

    2006-01-01

    Magnetite (Fe3O4) nanoparticles with different magnetic properties were prepared by coprecipitation of Fe3+ and Fe2+ with aqueous NaOH solution.The inductive heat properties of Fe3O4 nanoparticles in an alternating current (AC) magnetic field were investigated for local hyperthermia. The maximum saunder the optimum conditions of Fe3+:Fe2+ molar ratio at 1.8:1. The Ms of Fe3O4 nanoparticles decreased as the Fe3+ /Fe2+ molar ratio increased. But the coercivity Hc increases with the increasing of Fe3+ /Fe2+ molar ratio. Exposed in the AC magnetic field for 29 min, the temperatures of physiological saline suspension containing Fe3O4 nanoparticles were 42-97.5 ℃.The inductive heat property of Fe3O4 nanoparticles in AC magnetic field decreases as Hc increases, but increases with the increasing of Ms. The Fe3O4 nanoparticles would be useful as good thermoseeds for localized hyperthermia treatment of cancers.

  9. Pharmacokinetic parameters and tissue distribution of magnetic Fe3O4 nanoparticles in mice

    Directory of Open Access Journals (Sweden)

    Jun Wang

    2010-10-01

    Full Text Available Jun Wang1, Yue Chen1, Baoan Chen1, Jiahua Ding1, Guohua Xia1, Chong Gao1, Jian Cheng1, Nan Jin1, Ying Zhou1, Xiaomao Li1, Meng Tang2, Xue Mei Wang21Department of Hematology, Zhongda Hospital, Clinical Medical School, Southeast University, Nanjing, People’s Republic of China; 1Department of Physics, University of Saarland, D-266041 Saarbruechen, Germany; 2National Key Laboratory of Bioelectronics (Chien-Shiung Wu Laboratory, Southeast University, Nanjing, People’s Republic of ChinaBackground: This study explored the pharmacokinetic parameters and tissue distribution of magnetic iron oxide nanoparticles (Fe3O4 MNPs in imprinting control region (ICR mice.Methods: The Fe3O4 MNPs were synthesized by chemical coprecipitation, and their morphology and appearance were observed by transmission electron microscopy. ICR mice were divided into a control group and a Fe3O4 MNP-treated group. Probable target organs in ICR mice were observed, and the pharmacokinetic parameters and biodistribution of Fe3O4 MNPs in tissues were identified using atomic absorption spectrophotometry.Results: Fe3O4 MNPs were spherical with a well distributed particle diameter, and were distributed widely in various target organs and tissues including the heart, liver, spleen, lungs, kidneys, brain, stomach, small intestine, and bone marrow. The majority of Fe3O4 MNPs were distributed to the liver and the spleen. Fe3O4 MNP levels in brain tissue were higher in the Fe3O4 MNP-treated group than in the control group, indicating that Fe3O4 MNPs can penetrate the blood–brain barrier.Conclusion: These results suggest that the distribution of Fe3O4 MNPs was mostly in the liver and spleen, so the curative effect of these compounds could be more pronounced for liver tumors. Furthermore, Fe3O4 MNPs might be used as drug carriers to overcome physiologic barriers.Keywords: magnetic nanoparticles, Fe3O4, tissue distribution, mice

  10. Magnetic field synthesis of Fe 3O 4 nanoparticles used as a precursor of ferrofluids

    Science.gov (United States)

    Hong, R. Y.; Pan, T. T.; Han, Y. P.; Li, H. Z.; Ding, J.; Han, Sijin

    2007-03-01

    Methods to synthesize magnetic Fe 3O 4 nanoparticles and to modify the nanoparticle surface are presented in this paper. In these methods, Fe 3O 4 nanoparticles were prepared by co-precipitation, and the aging of nanoparticles was improved by applied magnetic field. The obtained nanoparticles were characterized by Fourier transform infrared spectroscopy (FT-IR), scanning electron microscopy (SEM), X-ray powder diffraction (XRD), and vibrating sample magnetometer (VSM). Thereafter, to enhance the compatibility between nanoparticles and water, an effective surface modification method was developed by grafting acrylic acid onto the nanoparticle surface. FT-IR, XRD, transmission electron microscopy (TEM), and thermogravimetry (TG) were used to characterize the resultant sample. The testing results indicated that the polyacrylic acid chains have been covalently bonded to the surface of magnetic Fe 3O 4 nanoparticles. The effects of initiator dosage, monomer concentration, and reaction temperature on the characteristics of surface-modified Fe 3O 4 nanoparticles were investigated. Moreover, the Fe 3O 4-g-PAA hybrid nanoparticles were dispersed in water to form ferrofluids (FFs). The obtained FFs were characterized by UV-vis spectrophotometer, Gouy magnetic balance and laser particle-size analyzer. The testing results showed that the high-concentration FF had excellent stability, with high susceptibility and high saturation magnetization. The rheological properties of the FFs were also investigated using a rotating rheometer.

  11. Synthesis of composite magnetic nanoparticles Fe3O4 with alendronate for osteoporosis treatment

    Science.gov (United States)

    Lee, Ming-Song; Su, Chao-Ming; Yeh, Jih-Chao; Wu, Pei-Ru; Tsai, Tien-Yao; Lou, Shyh-Liang

    2016-01-01

    Osteoporosis is a result of imbalance between bone formation by osteoblasts and resorption by osteoclasts (OCs). In the present study, we investigated the potential of limiting the aggravation of osteoporosis by reducing the activity of OCs through thermolysis. The proposed method is to synthesize bisphosphonate (Bis)-conjugated iron (II, III) oxide (Fe3O4) nanoparticles and incorporate them into OCs. The cells should be subsequently exposed to radiofrequency (RF) to induce thermolysis. In this study, particles of Fe3O4 were first synthesized by chemical co-precipitation and then coated with dextran (Dex). The Dex/Fe3O4 particles were then conjugated with Bis to form Bis/Dex/Fe3O4. Transmission electron microscopy revealed that the average diameter of the Bis/Dex/Fe3O4 particles was ~20 nm. All three kinds of nanoparticles were found to have cubic inverse spinel structure of Fe3O4 by the X-ray diffraction analysis. Fourier transform infrared spectroscopy confirmed that the Dex/Fe3O4 and Bis/Dex/Fe3O4 nanoparticles possessed their respective Dex and Bis functional groups, while a superconducting quantum interference device magnetometer measured the magnetic moment to be 24.5 emu. In addition, the Bis/Dex/Fe3O4 nanoparticles were fully dispersed in double-distilled water. Osteoblasts and OCs were individually cultured with the nanoparticles, and an MTT assay revealed that they were non-cytotoxic. An RF system (42 kHz and 450 A) was used to raise the temperature of the nanoparticles for 20 minutes, and the thermal effect was found to be sufficient to destroy OCs. Furthermore, in vivo studies verified that nanoparticles were indeed magnetic resonance imaging contrast agents and that they accumulated after being injected into the body of rats. In conclusion, we developed a water-dispersible magnetic nanoparticle that had RF-induced thermogenic properties, and the results indicated that the Bis/Dex/Fe3O4 nanoparticle had the potential for controlling osteoporosis.

  12. Effect of silica capping on the oxidation of Fe3O4 nanoparticles in dispersion revealed by x-ray absorption spectroscopy

    Science.gov (United States)

    Warland, A.; Antoniak, C.; Darbandi, M.; Weis, C.; Landers, J.; Keune, W.; Wende, H.

    2012-06-01

    Fe3O4 nanoparticles have been investigated as they are biocompatible and their surface can be functionalized. We synthesized iron oxide nanoparticles using a water-in-oil microemulsion method. Bare and silica-coated iron oxide nanoparticles of a core size of 6 nm dispersed in ethanol have been investigated by means of x-ray absorption spectroscopy (XAS). Due to a dedicated experimental setup the particles can be measured directly in dispersion. XAS allows us to disentangle the contributions of the Fe2+ and Fe3+ ions and therefore to estimate the amount of Fe3O4 in the particles. In case of the silica coated particles a high amount of magnetite was obtained. In contrast, the bare nanoparticles showed indications of a further oxidation into γ-Fe2O3 even in dispersion.

  13. Fe3O4/Au composite nano-particles and their optical properties

    Institute of Scientific and Technical Information of China (English)

    CUI; Yali; HUI; Wenli; SU; Jing; WANG; Yani; CHEN; Chao

    2005-01-01

    Fe3O4/Au composite particles with core/shell structure were prepared by reduction of Au3+ with hydroxylamine in the presence of an excess of Fe3O4 as seeds.The resultant colloids, with an average diameter of less than 100 nm, were obtained; the remaining non-reacted Fe3O4 seeds can be removed by treatment with diluted HCl solution.The Fe3O4/Au colloids exhibit a characteristic peak of UV-visible spectra, which largely depend on the size of the particle and the suspension medium.The localized surface plasmon resonance peaks red shift and broaden with increased nanoparticle diameter or increased solvent ionic strength.The optical property is very important in the establishment of means for the detection of biomolecules.

  14. TEA controllable preparation of magnetite nanoparticles (Fe3O4 NPs) with excellent magnetic properties

    Science.gov (United States)

    Han, Chengliang; Zhu, Dejie; Wu, Hanzhao; Li, Yao; Cheng, Lu; Hu, Kunhong

    2016-06-01

    A fast and controllable synthesis method for superparamagnetic magnetite nanoparticles (Fe3O4 NPs) was developed in Fe(III)-triethanolamine (TEA) solution. The phase structure, morphology and particle size of the as-synthesized samples were characterized by X-ray diffraction (XRD) and transmission electron microscopy (TEM). The results showed that the magnetic particles were pure Fe3O4 with mean sizes of approximately 10 nm. The used TEA has key effects on the formation of well dispersing Fe3O4 NPs. Vibrating sample magnetometer (VSM) result indicated that the as-obtained Fe3O4 NPs exhibited superparamagnetic behavior and the saturation magnetization (Ms) was about 70 emu/g, which had potential applications in magnetic science and technology.

  15. Green Synthesis of Magnetite (Fe3O4) Nanoparticles Using Seaweed ( Kappaphycus alvarezii) Extract

    Science.gov (United States)

    Yew, Yen Pin; Shameli, Kamyar; Miyake, Mikio; Kuwano, Noriyuki; Bt Ahmad Khairudin, Nurul Bahiyah; Bt Mohamad, Shaza Eva; Lee, Kar Xin

    2016-06-01

    In this study, a simple, rapid, and eco-friendly green method was introduced to synthesize magnetite nanoparticles (Fe3O4-NPs) successfully. Seaweed Kappaphycus alvarezii ( K. alvarezii) was employed as a green reducing and stabilizing agents. The synthesized Fe3O4-NPs were characterized with X-ray diffraction (XRD), ultraviolet-visible spectroscopy (UV-Vis), Fourier transform infrared (FT-IR), and transmission electron microscopy (TEM) techniques. The X-ray diffraction planes at (220), (311), (400), (422), (511), (440), and (533) were corresponding to the standard Fe3O4 patterns, which showed the high purity and crystallinity of Fe3O4-NPs had been synthesized. Based on FT-IR analysis, two characteristic absorption peaks were observed at 556 and 423 cm-1, which proved the existence of Fe3O4 in the prepared nanoparticles. TEM image displayed the synthesized Fe3O4-NPs were mostly in spherical shape with an average size of 14.7 nm.

  16. Green Synthesis of Magnetite (Fe3O4) Nanoparticles Using Seaweed (Kappaphycus alvarezii) Extract.

    Science.gov (United States)

    Yew, Yen Pin; Shameli, Kamyar; Miyake, Mikio; Kuwano, Noriyuki; Bt Ahmad Khairudin, Nurul Bahiyah; Bt Mohamad, Shaza Eva; Lee, Kar Xin

    2016-12-01

    In this study, a simple, rapid, and eco-friendly green method was introduced to synthesize magnetite nanoparticles (Fe3O4-NPs) successfully. Seaweed Kappaphycus alvarezii (K. alvarezii) was employed as a green reducing and stabilizing agents. The synthesized Fe3O4-NPs were characterized with X-ray diffraction (XRD), ultraviolet-visible spectroscopy (UV-Vis), Fourier transform infrared (FT-IR), and transmission electron microscopy (TEM) techniques. The X-ray diffraction planes at (220), (311), (400), (422), (511), (440), and (533) were corresponding to the standard Fe3O4 patterns, which showed the high purity and crystallinity of Fe3O4-NPs had been synthesized. Based on FT-IR analysis, two characteristic absorption peaks were observed at 556 and 423 cm(-1), which proved the existence of Fe3O4 in the prepared nanoparticles. TEM image displayed the synthesized Fe3O4-NPs were mostly in spherical shape with an average size of 14.7 nm. PMID:27251326

  17. Controllable synthesis and characterization of Fe3O4/Au composite nanoparticles

    International Nuclear Information System (INIS)

    Fe3O4/Au composite nanoparticles (GoldMag NPs) have received considerable attention because of their advantageous properties arisen from both individual Au and Fe3O4 nanoparticles. Many efforts have been devoted to the synthesis of these composite nanoparticles. Herein, GoldMag NPs were reported to be synthesized by two-step method. Fe3O4 nanoparticles were prepared by co-precipitation and modified by the citric acid, and then citric acid-coated Fe3O4 nanoparticles were used as seeds in sodium citrate solution to reduce the HAuCl4. The size of obtained nanoparticles was geared from 25 to 300 nm by controlling the concentration of reactants. The GoldMag NPs were characterized by UV–vis spectrometer, dynamic light scattering (DLS), transmission electron microscopy (TEM), X-ray photoelectron spectroscopy (XPS), X-ray diffraction (XRD), and vibrating sample magnetometer (VSM). The GoldMag NPs showed good superparamagnetism at room temperature and were well dispersed in water with surface plasmon resonance absorption peak varied from 538 nm to 570 nm. - Highlights: • A low cost, simple manipulation and nontoxic approach was designed for preparation of magnetic Fe3O4/Au (GoldMag NPs) nanocomposites. • The size of GoldMag NPs could be controlled from 25 to 300 nm by varying the concentration of reactants. • GoldMag NPs possessed good magnetic response, high dispersion, and good stability

  18. Controlled Synthesis and Characterization of Monodisperse Fe3O4 Nanoparticles

    Institute of Scientific and Technical Information of China (English)

    SHI,Rongrong; GAO,Guanhua; YI,Ran; ZHOU,Kechao; QIU,Guanzhou; LIU,Xiaohe

    2009-01-01

    Monodisperse Fe3O4 nanoparticles were successfully synthesized through the thermal decomposition of iron acetylacetonate in octadecene solvent in the presence of oleic acid and oleylamine.The influences of experimental parameters,such as reacting temperature,amounts and kinds of surfactants,solvents,oleic acid and oleylamine,on the size and shape of monodisperse Fe3O4 nanoparticles were discussed.The phase structures,morphology,and size of the as-prepared products were investigated in detail by X-ray diffraction (XRD),transmission electron microscopy (TEM),selected area electron diffraction (SAED) and high-resolution transmission electron microscopy (HRTEM).Magnetic property was measured using a vibrating sample magnetometer (VSM) at room temperature,which revealed that Fe3O4 nanoparticles were of ferromagnetism with a saturation magnetization (Ms) of 74.0 emu/g and coercivity (Hc) of 72.6 Oe.

  19. Inductive heat property of Fe3O4/polymer composite nanoparticles in an ac magnetic field for localized hyperthermia.

    Science.gov (United States)

    Zhao, Dong-Lin; Zhang, Hai-Long; Zeng, Xian-Wei; Xia, Qi-Sheng; Tang, Jin-Tian

    2006-12-01

    The magnetite (Fe(3)O(4)) nanoparticles were prepared by coprecipitation of Fe(3+) and Fe(2+) with an aqueous NaOH solution. The Fe(3)O(4)/polyaniline (PANI) magnetic composite nanoparticles with a core-shell structure with a diameter of 30-50 nm were prepared via an in situ polymerization of aniline in an aqueous solution containing the Fe(3)O(4) magnetic fluid. The inductive heat property of Fe(3)O(4)/PANI composite nanoparticles in an alternating current (ac) magnetic field was investigated. The potential of Fe(3)O(4)/PANI nanoparticles was evaluated for localized hyperthermia treatment of cancers. The saturation magnetization, M(s), and coercivity, H(c), are 50.05 emu g(-1) and 137 Oe for Fe(3)O(4) nanoparticles and 26.34 emu g(-1) and 0 Oe for Fe(3)O(4)/PANI composite nanoparticles, respectively. Exposed in the ac magnetic field for 29 min, the temperatures of physiological saline suspensions containing Fe(3)O(4) nanoparticles or Fe(3)O(4)/PANI composite nanoparticles are 63.6 degrees C and 52.4 degrees C, respectively. The Fe(3)O(4)/PANI composite nanoparticles would be useful as good thermoseeds for localized hyperthermia treatment of cancers. PMID:18458406

  20. Hydrothermal fabrication of octahedral-shaped Fe3O4 nanoparticles and their magnetorheological response

    Science.gov (United States)

    Jung, H. S.; Choi, H. J.

    2015-05-01

    Octahedral-shaped Fe3O4 nanoparticles were synthesized in the presence of 1,3-diaminopropane using a hydrothermal method and assessed as a potential magnetorheological (MR) material. Their morphology, crystal structure, and magnetic properties were examined by scanning electron microscopy, transmission electron microscopy, X-ray diffraction, and vibrating sample magnetometry, respectively. The MR characteristics of the octahedral-shaped, Fe3O4 nanoparticle-based MR particles when dispersed in silicone oil with a 10 vol. % particle concentration were examined using a rotational rheometer under an external magnetic field. The resulting MR fluids exhibited a Bingham-like behavior with a distinctive yield stress from their flow curves.

  1. Green synthesis and characterization of superparamagnetic Fe 3O 4 nanoparticles

    Science.gov (United States)

    Lu, Wensheng; Shen, Yuhua; Xie, Anjian; Zhang, Weiqiang

    2010-07-01

    In this paper, we have first demonstrated a facile and green synthetic approach for preparing superparamagnetic Fe 3O 4 nanoparticles using α- D-glucose as the reducing agent and gluconic acid (the oxidative product of glucose) as stabilizer and dispersant. The X-ray powder diffraction (XRD), X-ray photoelectron spectrometry (XPS), and selected area electron diffraction (SAED) results showed that the inverse spinel structure pure phase polycrystalline Fe 3O 4 was obtained. The scanning electron microscopy (SEM) and transmission electron microscopy (TEM) results exhibited that Fe 3O 4 nanoparticles were roughly spherical shape and its average size was about 12.5 nm. The high-resolution TEM (HRTEM) result proved that the nanoparticles were structurally uniform with a lattice fringe spacing about 0.25 nm, which corresponded well with the values of 0.253 nm of the (3 1 1) lattice plane of the inverse spinel Fe 3O 4 obtained from the JCPDS database. The superconducting quantum interference device (SQUID) results revealed that the blocking temperature ( Tb) was 190 K, and that the magnetic hysteresis loop at 300 K showed a saturation magnetization of 60.5 emu/g, and the absence of coercivity and remanence indicated that the as-synthesized Fe 3O 4 nanoparticles had superparamagnetic properties. Fourier transform infrared spectroscopy (FT-IR) spectrum displayed that the characteristic band of Fe-O at 569 cm -1 was indicative of Fe 3O 4. This method might provide a new, mild, green, and economical concept for the synthesis of other nanomaterials.

  2. Mössbauer investigations of Fe and Fe3O4 magnetic nanoparticles for hyperthermia applications

    Science.gov (United States)

    Kamzin, A. S.

    2016-03-01

    Magnetic nanoparticles of magnetite Fe3O4 and Fe synthesized by physical vapor deposition with a fast highly effective method using a solar energy have been studied. Targets have been prepared from tablets pressed from Fe3O4 or Fe powders. Relationships between the structure of nanoparticles and their magnetic properties have been investigated in order to understand principles of the control of the parameters of magnetic nanoparticles. Mössbauer investigations have revealed that the nanoparticles synthesized from tablets of both pure iron and Fe3O4 consist of two phases: pure iron and iron oxides (γ-Fe2O3 and Fe3O4). The high iron oxidability suggests that the synthesized nanoparticles have a core/shell structure, where the core is pure iron and the shell is an oxidized iron layer. Magnetite nanoparticles synthesized at a pressure of 80 Torr have the best parameters for hyperthermia due to their core/shell structure and core-to-shell volume ratio.

  3. Tunable fluorescence enhancement based on bandgap-adjustable 3D Fe3O4 nanoparticles

    Science.gov (United States)

    Hu, Fei; Gao, Suning; Zhu, Lili; Liao, Fan; Yang, Lulu; Shao, Mingwang

    2016-06-01

    Great progress has been made in fluorescence-based detection utilizing solid state enhanced substrates in recent years. However, it is still difficult to achieve reliable substrates with tunable enhancement factors. The present work shows liquid fluorescence enhanced substrates consisting of suspensions of Fe3O4 nanoparticles (NPs), which can assemble 3D photonic crystal under the external magnetic field. The photonic bandgap induced by the equilibrium of attractive magnetic force and repulsive electrostatic force between adjacent Fe3O4 NPs is utilized to enhance fluorescence intensity of dye molecules (including R6G, RB, Cy5, DMTPS-DCV) in a reversible and controllable manner. The results show that a maximum of 12.3-fold fluorescence enhancement is realized in the 3D Fe3O4 NP substrates without the utilization of metal particles for PCs/DMTPS-DCV (1.0 × 10‑7 M, water fraction (f w) = 90%).

  4. Magnetic Fe3O4 nanoparticle catalyzed chemiluminescence for detection of nitric oxide in living cells.

    Science.gov (United States)

    Wang, Huiliang; Li, Mei; Wang, Bing; Wang, Meng; Kurash, Ibrahim; Zhang, Xiangzhi; Feng, Weiyue

    2016-08-01

    Direct and real-time measurement of nitric oxide (NO) in biological media is very difficult due to its transient nature. Fe3O4 nanoparticles (nanoFe3O4) because of their unique catalytic activities have attracted much attention as catalysts in a variety of organic and inorganic reactions. In this work, we have developed a magnetic Fe3O4 nanoparticle-based rapid-capture system for real-time detection of cellular NO. The basic principle is that the nanoFe3O4 can catalyze the decomposition of H2O2 in the system to generate superoxide anion (O2 (·-)) and the O2 (·-) can serve as an effective NO(·) trapping agent yielding peroxynitrite oxide anion, ONOO(-). Then the concentration of NO in cells can be facilely determined via peroxynitrite-induced luminol chemiluminescence. The linear range of the method is from 10(-4) to 10(-8) mol/L, and the detection of limit (3σ, n = 11) is as low as 3.16 × 10(-9) mol/L. By using this method, the NO concentration in 0.1 and 0.5 mg/L LPS-stimulated BV2 cells was measured as 4.9 and 11.3 μM, respectively. Surface measurements by synchrotron X-ray photoelectron spectroscopy (SRXPS) and scanning transmission X-ray microscopy (STXM) demonstrate the catalytic mechanism of the nanoFe3O4-based system is that the significantly excess Fe(II) exists on the surface of nanoFe3O4 and mediates the rapid heterogeneous electron transfer, thus presenting a new Fe2O3 phase on the surface.

  5. Magnetic Fe3O4 nanoparticle catalyzed chemiluminescence for detection of nitric oxide in living cells.

    Science.gov (United States)

    Wang, Huiliang; Li, Mei; Wang, Bing; Wang, Meng; Kurash, Ibrahim; Zhang, Xiangzhi; Feng, Weiyue

    2016-08-01

    Direct and real-time measurement of nitric oxide (NO) in biological media is very difficult due to its transient nature. Fe3O4 nanoparticles (nanoFe3O4) because of their unique catalytic activities have attracted much attention as catalysts in a variety of organic and inorganic reactions. In this work, we have developed a magnetic Fe3O4 nanoparticle-based rapid-capture system for real-time detection of cellular NO. The basic principle is that the nanoFe3O4 can catalyze the decomposition of H2O2 in the system to generate superoxide anion (O2 (·-)) and the O2 (·-) can serve as an effective NO(·) trapping agent yielding peroxynitrite oxide anion, ONOO(-). Then the concentration of NO in cells can be facilely determined via peroxynitrite-induced luminol chemiluminescence. The linear range of the method is from 10(-4) to 10(-8) mol/L, and the detection of limit (3σ, n = 11) is as low as 3.16 × 10(-9) mol/L. By using this method, the NO concentration in 0.1 and 0.5 mg/L LPS-stimulated BV2 cells was measured as 4.9 and 11.3 μM, respectively. Surface measurements by synchrotron X-ray photoelectron spectroscopy (SRXPS) and scanning transmission X-ray microscopy (STXM) demonstrate the catalytic mechanism of the nanoFe3O4-based system is that the significantly excess Fe(II) exists on the surface of nanoFe3O4 and mediates the rapid heterogeneous electron transfer, thus presenting a new Fe2O3 phase on the surface. PMID:27289465

  6. Biocompatibility of magnetic Fe3O4 nanoparticles and their cytotoxic effect on MCF-7 cells

    Directory of Open Access Journals (Sweden)

    Chen DZ

    2012-09-01

    Full Text Available Daozhen Chen,1,3,* Qiusha Tang,2,* Xiangdong Li,3,* Xiaojin Zhou,1 Jia Zang,1 Wen-qun Xue,1 Jing-ying Xiang,1 Cai-qin Guo11Central Laboratory, Wuxi Hospital for Matemaland Child Health Care Affiliated Medical School of Nanjing, Jiangsu Province; 2Department of Pathology and Pathophysiology, Medical College, Southeast University, Jiangsu Province; 3The People’s Hospital of Aheqi County, Xinjiang, China *These authors contributed equally to this workBackground: The objective of this study was to evaluate the synthesis and biocompatibility of Fe3O4 nanoparticles and investigate their therapeutic effects when combined with magnetic fluid hyperthermia on cultured MCF-7 cancer cells.Methods: Magnetic Fe3O4 nanoparticles were prepared using a coprecipitation method. The appearance, structure, phase composition, functional groups, surface charge, magnetic susceptibility, and release in vitro were characterized by transmission electron microscopy, x-ray diffraction, scanning electron microscopy-energy dispersive x-ray spectroscopy, and a vibrating sample magnetometer. Blood toxicity, in vitro toxicity, and genotoxicity were investigated. Therapeutic effects were evaluated by MTT [3-(4, 5-dimethyl-2-thiazolyl-2, 5-diphenyl-2H-tetrazolium bromide] and flow cytometry assays.Results: Transmission electron microscopy revealed that the shapes of the Fe3O4 nanoparticles were approximately spherical, with diameters of about 26.1 ± 5.2 nm. Only the spinel phase was indicated in a comparison of the x-ray diffraction data with Joint Corporation of Powder Diffraction Standards (JCPDS X-ray powder diffraction files. The O-to-Fe ratio of the Fe3O4 was determined by scanning electron microscopy-energy dispersive x-ray spectroscopy elemental analysis, and approximated pure Fe3O4. The vibrating sample magnetometer hysteresis loop suggested that the Fe3O4 nanoparticles were superparamagnetic at room temperature. MTT experiments showed that the toxicity of the material

  7. Water dispersible oleic acid-coated Fe3O4 nanoparticles for biomedical applications

    International Nuclear Information System (INIS)

    Fe3O4 magnetic nanoparticles (MNPs) have proved their tremendous potential to be used for various biomedical applications. Oleic acid (OA) is widely used in ferrite nanoparticle synthesis because it can form a dense protective monolayer, thereby producing highly uniform and monodispersed particles. Capping agents such as oleic acid are often used because they form a protective monolayer, which is strongly bonded to the surface of nanoparticles. This is necessary for making monodisperse and highly uniform MNPs. Coating of Fe3O4 MNPs with OA makes the particles dispersible only in organic solvents and consequently limits their use for biomedical applications. Hence, in this work, the OA coated MNPs were again functionalized with chitosan (CS), in order to impart hydrophilicity on their surface. All the morphological, magnetic, colloidal and cytotoxic characteristics of the resulting core–shells were studied thoroughly. Their heating induction ability was studied to predict their possible use in hyperthermia therapy of cancer. Specific absorption rate was found to be increased than that of bare MNPs. - Highlights: • Fe3O4 nanoparticles synthesized FeCl2 as the sole source by alkaline precipitation. • Hydrophilicity imparted to OA-Fe3O4 MNPs. • Improved heating induction ability. • Highly stabilized colloidal suspension. • Improved biocompatiblity

  8. Reversed ageing of Fe3O4 nanoparticles by hydrogen plasma

    Science.gov (United States)

    Schmitz-Antoniak, Carolin; Schmitz, Detlef; Warland, Anne; Svechkina, Nataliya; Salamon, Soma; Piamonteze, Cinthia; Wende, Heiko

    2016-02-01

    Magnetite (Fe3O4) nanoparticles suffer from severe ageing effects when exposed to air even when they are dispersed in a solvent limiting their applications. In this work, we show that this ageing can be fully reversed by a hydrogen plasma treatment. By x-ray absorption spectroscopy and its associated magnetic circular dichroism, the electronic structure and magnetic properties were studied before and after the plasma treatment and compared to results of freshly prepared magnetite nanoparticles. While aged magnetite nanoparticles exhibit a more γ-Fe2O3 like behaviour, the hydrogen plasma yields pure Fe3O4 nanoparticles. Monitoring the temperature dependence of the intra-atomic spin dipole contribution to the dichroic spectra gives evidence that the structural, electronic and magnetic properties of plasma treated magnetite nanoparticles can outperform the ones of the freshly prepared batch.

  9. Effect of annealing temperature on magnetic phase transition in Fe3O4 nanoparticles

    International Nuclear Information System (INIS)

    Fe3O4 (magnetite) nanoparticles (NPs) were synthesized using a co-precipitation method, and then annealed at various temperatures between 50 and 850 °C for 1 h in air. After annealing, the NPs were characterized by X-ray diffraction (XRD), Fourier transform infrared (FT-IR) spectroscopy and vibrating sample magnetometer (VSM). The FTIR and XRD results indicated that Fe3O4 NPs were converted to γ-Fe2O3 (maghemite) by annealing at 250 °C for 1 h and then to α-Fe2O3 (hematite) on annealing in the range of 550–650 °C. The average crystallite size of the NPs estimated by the Debye–Scherrer equation increased from 6.6 to 37.6 nm by increasing annealing temperature from 50 to 850 °C. According to VSM results, the magnetite NPs were superparamagnetic and converted to the maghemite with superparamagnetic phase by annealing up to 550 °C. A phase transition from soft to hard ferromagnetic was occurred at annealing temperature 650 and 850 °C, respectively °C. This phase transition was attributed to the conversion of magnetite to hematite. The VSM analysis confirmed the XRD and FTIR results. The saturation magnetization (Ms) of Fe3O4 NPs was increased from 41.69 to 53.61 emu/g by increasing annealing temperature from 50 to 550 °C, and then decreased intensively to 0.49 emu/g after annealing at 850 °C. By increasing annealing temperature from 50 to 550, the crystallite size of NPs was increased from 6.6 to 12.7 and the coercive force (Hc) was reached to 4.20 Oe after annealing at 550 °C and then intensively increased to 1459.02 Oe for any further increasing of particle size up to 850 °C. - Highlights: • Fe3O4 nanoparticles (NPs) were synthesized using a co-precipitation method. • Prepared NPs annealed at 50, 250, 350, 450, 550, 650, 750, and 850°C for 1h in air. • Transform of superpara Fe3O4 to superpara γ-Fe2O3 occurred by annealing at 250 °C. • Superpara Fe3O4 transformed into α-Fe2O3, with soft ferromagnetic phase at 650 °C.

  10. Simple solvothermal synthesis of hydrophobic magnetic monodispersed Fe3O4 nanoparticles

    International Nuclear Information System (INIS)

    Graphical abstract: A facile method to produce monodispersed magnetite nanoparticles is based on the solvothermal reaction of iron acetylacetonate (Fe(acac)3) decomposition. The sizes ranged from 7 to 12 nm, which could be controlled by adjusting the volume ratio of oleylamine to n-hexane. Display Omitted Highlights: ► The solvethermal reaction of Fe(acac)3 decomposition was carried out at mild temperature in the presence of oleylamine and n-hexane. ► The size of nanocrystals is controlled by adjusting the volume ratio of oleylamine to n-hexane. ► The low-boiling-point solvent n-hexane offered autogenous pressure parameter after gasified in the reaction temperature. ► The as prepared hydrophobic monodisperse Fe3O4 NPs can be used to prepare the magnetic micelles for future biomedical applications. -- Abstract: A new solvothermal method is proposed for the preparation of Fe3O4 nanoparticles (NPs) from iron acetylacetonate in the presence of oleylamine and n-hexane. The products are characterized by X-ray powder diffraction, infrared (IR) spectroscopy, transmission electron microscopy, thermogravimetry/differential thermogravimetry (TG/DTG) analysis, and vibrating sample magnetometery. The new procedure yields superparamagnetic monodispersed Fe3O4 particles with sizes ranging from 7 nm to 12 nm. The nanocrystal sizes are controlled by adjusting the volume ratio of oleylamine to n-hexane. IR and TG/DTG analyses indicate that the oleylamine molecules, as stabilizers, are adsorbed on the surface of Fe3O4 NPs as bilayer adsorption models. The surface adsorption quantities of oleylamine on 7.5 and 10.4 nm-diameter Fe3O4 NPs are 18% and 11%, respectively. The hydrophobic surface of the obtained nanocrystals is passivated by adsorbed organic solvent molecules. These molecules provide stability against agglomeration, enable solubility in nonpolar solvents, and allow the formation of magnetic polymer micelles.

  11. Removal of Pb2+, Hg2+, and Cu2+ by Chain-Like Fe3O4@SiO2@Chitosan Magnetic Nanoparticles.

    Science.gov (United States)

    Shi, Haowei; Yang, Junya; Zhu, Lizhong; Yang, Yuxiang; Yuan, Hongming; Yang, Yubing; Liu, Xiangnong

    2016-02-01

    In this paper, the chain-like core-shell structure Fe3O4@SiO2@Chitosan composite nanoparticles were synthesized by a two-step coating and following crosslinking glutaraldehyde on chitosan shell. The composite particles showed nearly monodisperse 105 sized particles with a core diameter of 80 nm and chitosan shell thickness of 12 nm. The synthesis conditions of the product were studied, and the morphology and properties of the composite nanoparticles were characterized by IR, XRD, TEM, SEM, EDS and VSM. The adsorption properties of Hg2+, Pb2+ or Cu2+ ions on Fe3O4, Fe3O4@SiO2 and the composite particles were in detail studied using the colorimetric method based on forming colored mercuric dithizone, rhodamine-Pb2+ complex and DDTC-Cu(2+) complex. The results showed, adsorption isotherm, kinetics and separation coefficient of heavy metal ions on these three magnetic nanoparticles were concerned with pH, metal ions' electronic configuration, silica coating and chitosan shell respectively. In addition, the recycle efficiency was also studied. The findings demonstrated that Fe3O4@SiO2@Chitosan composite nanoparticles have great application value in the adsorption and separation of heavy metal ions. PMID:27433691

  12. Aloe vera plant-extracted solution hydrothermal synthesis and magnetic properties of magnetite (Fe3O4) nanoparticles

    Science.gov (United States)

    Phumying, Santi; Labuayai, Sarawuth; Thomas, Chunpen; Amornkitbamrung, Vittaya; Swatsitang, Ekaphan; Maensiri, Santi

    2013-06-01

    Magnetite (Fe3O4) nanoparticles have been successfully synthesized by a novel hydrothermal method using ferric acetylacetonate (Fe(C5H8O2)3) and aloe vera plant-extracted solution. The influences of different reaction temperatures and times on the structure and magnetic properties of the synthesized Fe3O4 nanoparticles were investigated. The synthesized nanoparticles are crystalline and have particle sizes of ˜6-30 nm, as revealed by transmission electron microscopy (TEM). The results of X-ray diffraction (XRD), High resolution TEM (HRTEM) and selected area electron diffraction (SAED) indicate that the synthesized Fe3O4 nanoparticles have the inverse cubic spinel structure without the presence of any other phase impurities. The hysteresis loops of the Fe3O4 nanoparticles at room temperature show superparamagnetic behavior and the saturation magnetization of the Fe3O4 samples increases with increasing reaction temperature and time.

  13. Multifunctional glucose biosensors from Fe3O4 nanoparticles modified chitosan/graphene nanocomposites

    OpenAIRE

    Wenjing Zhang; Xiaojian Li; Ruitao Zou; Huizi Wu; Haiyan Shi; Shanshan Yu; Yong Liu

    2015-01-01

    Novel water-dispersible and biocompatible chitosan-functionalized graphene (CG) has been prepared by a one-step ball milling of carboxylic chitosan and graphite. Presence of nitrogen (from chitosan) at the surface of graphene enables the CG to be an outstanding catalyst for the electrochemical biosensors. The resulting CG shows lower ID/IG ratio in the Raman spectrum than other nitrogen-containing graphene prepared using different techniques. Magnetic Fe3O4 nanoparticles (MNP) are further int...

  14. The Magnetorheological Finishing (MRF) of Potassium Dihydrogen Phosphate (KDP) Crystal with Fe3O4 Nanoparticles

    OpenAIRE

    Ji, Fang; Xu, Min; Wang, Chao; Li, Xiaoyuan; Gao, Wei; Zhang, Yunfei; Wang, Baorui; Tang, Guangping; Yue, Xiaobin

    2016-01-01

    The cubic Fe3O4 nanoparticles with sharp horns that display the size distribution between 100 and 200 nm are utilized to substitute the magnetic sensitive medium (carbonyl iron powders, CIPs) and abrasives (CeO2/diamond) simultaneously which are widely employed in conventional magnetorheological finishing fluid. The removal rate of this novel fluid is extremely low compared with the value of conventional one even though the spot of the former is much bigger. This surprising phenomenon is gene...

  15. Seeded preparation of ultrathin FeS2 nanosheets from Fe3O4 nanoparticles

    Science.gov (United States)

    Li, Tingting; Liu, Huiwen; Wu, Zhennan; Liu, Yi; Guo, Zuoxing; Zhang, Hao

    2016-06-01

    FeS2 nanomaterials with two-dimensional features hold great promise for electrochemical and photovoltaic applications. However, the preparation of ultrathin FeS2 nanosheets is still challenging because of the lack of a tailor-made approach. In this work, FeS2 nanosheets with a thickness of 2.1 nm are prepared through a Fe3O4-seeded approach. Uniform Fe3O4 nanoparticles are foremost synthesized via the standard method in organic media. The injection of a S solution leads to the replacement of O in Fe3O4 through anion-exchange, which generates (110) facet-enriched FeS2 nuclei. The subsequent (110) facet-mediated oriented attachment and fusion of FeS2 nuclei produce ultrathin FeS2 nanosheets. As catalysts in the hydrogen evolution reaction, FeS2 nanosheets exhibit good electrochemical activity.FeS2 nanomaterials with two-dimensional features hold great promise for electrochemical and photovoltaic applications. However, the preparation of ultrathin FeS2 nanosheets is still challenging because of the lack of a tailor-made approach. In this work, FeS2 nanosheets with a thickness of 2.1 nm are prepared through a Fe3O4-seeded approach. Uniform Fe3O4 nanoparticles are foremost synthesized via the standard method in organic media. The injection of a S solution leads to the replacement of O in Fe3O4 through anion-exchange, which generates (110) facet-enriched FeS2 nuclei. The subsequent (110) facet-mediated oriented attachment and fusion of FeS2 nuclei produce ultrathin FeS2 nanosheets. As catalysts in the hydrogen evolution reaction, FeS2 nanosheets exhibit good electrochemical activity. Electronic supplementary information (ESI) available: EDX, AFM images, small-angle XRD pattern, SAED pattern, and TEM images of FeS2 nanosheets. See DOI: 10.1039/c6nr02211a

  16. Synthesis and characterization of Fe3O4-TiO2 core-shell nanoparticles

    Science.gov (United States)

    Stefan, M.; Pana, O.; Leostean, C.; Bele, C.; Silipas, D.; Senila, M.; Gautron, E.

    2014-09-01

    Composite core-shell nanoparticles may have morpho-structural, magnetic, and optical (photoluminescence (PL)) properties different from each of the components considered separately. The properties of Fe3O4-TiO2 nanoparticles can be controlled by adjusting the titania amount (shell thinness). Core-shell nanoparticles were prepared by seed mediated growth of semiconductor (TiO2) through a modified sol-gel process onto preformed magnetite (Fe3O4) cores resulted from the co-precipitation method. The structure and morphology of samples were characterized by X-ray diffraction, transmission electron microscopy (TEM), and high resolution-TEM respectively. X-ray photoelectron spectroscopy was correlated with ICP-AES. Magnetic measurements, optical absorption spectra, as well as PL spectroscopy indicate the presence of a charge/spin transfer from the conduction band of magnetite into the band gap of titania nanocrystals. The process modifies both Fe3O4 and TiO2 magnetic and optical properties, respectively.

  17. Synthesis and control of Fe3O4 magnetic nanoparticles%Fe_3O_4磁性纳米颗粒的合成及其调控

    Institute of Scientific and Technical Information of China (English)

    王海成; 汪凡曦; 于广华

    2012-01-01

    The fcc structured Fe3O4 nanoparticles are prepared using hydrolysis coprecipitation in this paper. The effect of temperature and pH on the grain size and shape of the Fe3O4 magnetic nanoparticles were discussed. The results show that, reaction temperature affects the size of Fe3O4 nanoparticles. As the temperature rising from 30 to 90℃, the grain size increases from 6-Snm to 10-12nm and the saturation magnetic moment also increases. Meanwhile, the shape of Fe3O4 nanoparticles varies according to the pH of the solution. High pH leads to cubic particles while low pH Causes spherical shape. The controllable size and shape of Fe3O4 nanoparticles lay a good foundation for further synthesis, regulation of electro-magnetic functional Fe3O4 composites.%利用水解共沉淀法制备了Fe3O4纳米颗粒,研究了温度和pH值对Fe3O4纳米颗粒粒径、形貌的影响关系。研究结果表明,反应温度从30℃升高到90℃,Fe3O4颗粒的粒径从6~8nm增大到10~12nm;同时,Fe3O4颗粒的饱和磁矩也随着Fe3O4颗粒粒径的增加而升高。溶液pH值会影响Fe3O4纳米颗粒的形状,高pH值易使合成的Fe3O4纳米颗粒为四方形,随着pH值的降低,Fe3O4纳米颗粒向球形转变。Fe3O4纳米颗粒的粒径和形状的可控性为进一步合成、调控Fe3O4电磁功能复合材料奠定了良好基础。

  18. Ultrafast Preparation of Monodisperse Fe3 O4 Nanoparticles by Microwave-Assisted Thermal Decomposition.

    Science.gov (United States)

    Liang, Yi-Jun; Zhang, Yu; Guo, Zhirui; Xie, Jun; Bai, Tingting; Zou, Jiemeng; Gu, Ning

    2016-08-01

    Thermal decomposition, as the main synthetic procedure for the synthesis of magnetic nanoparticles (NPs), is facing several problems, such as high reaction temperatures and time consumption. An improved a microwave-assisted thermal decomposition procedure has been developed by which monodisperse Fe3 O4 NPs could be rapidly produced at a low aging temperature with high yield (90.1 %). The as-synthesized NPs show excellent inductive heating and MRI properties in vitro. In contrast, Fe3 O4 NPs synthesized by classical thermal decomposition were obtained in very low yield (20.3 %) with an overall poor quality. It was found for the first time that, besides precursors and solvents, magnetic NPs themselves could be heated by microwave irradiation during the synthetic process. These findings were demonstrated by a series of microwave-heating experiments, Raman spectroscopy and vector-network analysis, indicating that the initially formed magnetic Fe3 O4 particles were able to transform microwave energy into heat directly and, thus, contribute to the nanoparticle growth. PMID:27381301

  19. Polyethyleneimine-modified superparamagnetic Fe3O4 nanoparticles: An efficient, reusable and water tolerance nanocatalyst

    International Nuclear Information System (INIS)

    A novel magnetically separable catalyst was prepared based on surface modification of Fe3O4 magnetic nanoparticle (MNPs) with polyethyleneimine (PEI) via covalent bonding. [3-(2,3-Epoxypropoxy)propyl]trimethoxysilane (EPO) was used as cross linker to bond PEI on the surface of MNPs with permanent stability in contrast to PEI coating via electrostatic interactions. The synthesized catalyst was characterized by Fourier transform infrared (FT-IR), thermogravimetric analysis (TGA), X-ray powder diffraction (XRD), transmission electron microscopy (TEM) and vibrating sample magnetometry (VSM). The catalyst show high efficiency for one-pot synthesis of 2-amino-3-cyano-4H-pyran derivatives via multi-component reaction (MCR). This procedure offers the advantages of green reaction media, high yield, short reaction time, easy purification of the products and simple recovery and reuse of the catalyst by simple magnetic decantation without significant loss of catalytic activity. - Graphical abstract: Covalently grafted polyethyleneimine on Fe3O4 magnetic nanoparticles as easily reusable catalyst for the synthesis of various 4H-pyrans. - Highlights: • Polyethyleneimine modified Fe3O4 via covalent bonding as a novel water tolerance catalyst. • The catalyst showed high efficiency for one-pot synthesis of 2-amino-3-cyano-4H-pyrans in water. • Catalysts could be easily recovered and reused for several times without a significant loss in their catalytic activity

  20. Magnetic hyperthermia in brick-like Ag@Fe3O4 core-shell nanoparticles

    Science.gov (United States)

    Brollo, M. E. F.; Orozco-Henao, J. M.; López-Ruiz, R.; Muraca, D.; Dias, C. S. B.; Pirota, K. R.; Knobel, M.

    2016-01-01

    Heating efficiency of multifunctional Ag@Fe3O4 brick-like nanoparticles under alternating magnetic field was investigated by means of specific absorption rate (SAR) measurements, and compared with equivalent measurements for plain magnetite and dimer heteroparticles. The samples were synthesized by thermal decomposition reactions and present narrow size polydispersity and high degree of crystallinity. The SAR values are analyzed using the superparamagnetic theory, in which the basic morphology, size and dispersion of sizes play key roles. The results suggest that these novel brick-like nanoparticles are good candidates for hyperthermia applications, displaying heating efficiencies comparable with the most efficient plain nanoparticles.

  1. Recent advances in the synthesis of Fe3O4@AU core/shell nanoparticles

    Science.gov (United States)

    Salihov, Sergei V.; Ivanenkov, Yan A.; Krechetov, Sergei P.; Veselov, Mark S.; Sviridenkova, Natalia V.; Savchenko, Alexander G.; Klyachko, Natalya L.; Golovin, Yury I.; Chufarova, Nina V.; Beloglazkina, Elena K.; Majouga, Alexander G.

    2015-11-01

    Fe3O4@Au core/shell nanoparticles have unique magnetic and optical properties. These nanoparticles are used for biomedical applications, such as magnetic resonance imaging, photothermal therapy, controlled drug delivery, protein separation, biosensors, DNA detection, and immunosensors. In this review, recent methods for the synthesis of core/shell nanoparticles are discussed. We divided all of the synthetic methods in two groups: methods of synthesis of bi-layer structures and methods of synthesis of multilayer composite structures. The latter methods have a layer of "glue" material between the core and the shell.

  2. Preparation and properties of bio-compatible magnetic Fe3O4 nanoparticles

    International Nuclear Information System (INIS)

    In this work, we study the preparation and properties of bio-compatible magnetic nanoparticles for immunoassay and DNA detection. The magnetite (Fe3O4) nanoparticles were prepared by a chemical co-precipitation method and dextran was selected as the surfactant to suspend the nanoparticles. Suspended particles associated with avidin followed by biotin were qualitatively analyzed by enzyme-linked immunosorbent assay (ELISA) method. We found further the ethylenediamine blocked activated residual groups efficiently, hence enhancing the attachment of biotin for probing the avidin

  3. Electrostatic self-assembly of Fe 3O 4 nanoparticles on carbon nanotubes

    Science.gov (United States)

    Liu, Yong; Jiang, Wei; Li, Song; Li, Fengsheng

    2009-06-01

    Carbon nanotubes (CNTs)-based magnetic nanocomposites can find numerous applications in nanotechnology, integrated functional system, and in medicine owing to their great potentialities. Herein, densely distributed magnetic Fe 3O 4 nanoparticles were successfully attached onto the convex surfaces of carbon nanotubes (CNTs) by an in situ polyol-medium solvothermal method via non-covalent functionalization of CNTs with cationic surfactant, cetyltrimethylammonium bromide (CTAB), and anionic polyelectrolyte, poly(sodium 4-styrenesulfonate) (PSS), through the polymer-wrapping technique, in which the negatively charged PSS-grafted CNTs can be used as primer for efficiently adsorption of positively metal ions on the basis of electrostatic attraction. X-ray diffractometry (XRD), X-ray photoelectron spectroscopy (XPS) and transmission electron microscopy (TEM) analysis have been used to study the formation of Fe 3O 4/CNTs. The Fe 3O 4/CNTs nanocomposites were proved to be superparamagnetic with saturation magnetization of 43.5 emu g -1. A mechanism scheme was proposed to illustrate the formation process of the magnetic nanocomposites.

  4. The Magnetorheological Finishing (MRF) of Potassium Dihydrogen Phosphate (KDP) Crystal with Fe3O4 Nanoparticles

    Science.gov (United States)

    Ji, Fang; Xu, Min; Wang, Chao; Li, Xiaoyuan; Gao, Wei; Zhang, Yunfei; Wang, Baorui; Tang, Guangping; Yue, Xiaobin

    2016-02-01

    The cubic Fe3O4 nanoparticles with sharp horns that display the size distribution between 100 and 200 nm are utilized to substitute the magnetic sensitive medium (carbonyl iron powders, CIPs) and abrasives (CeO2/diamond) simultaneously which are widely employed in conventional magnetorheological finishing fluid. The removal rate of this novel fluid is extremely low compared with the value of conventional one even though the spot of the former is much bigger. This surprising phenomenon is generated due to the small size and low saturation magnetization ( M s) of Fe3O4 and corresponding weak shear stress under external magnetic field according to material removal rate model of magnetorheological finishing (MRF). Different from conventional D-shaped finishing spot, the low M s also results in a shuttle-like spot because the magnetic controllability is weak and particles in the fringe of spot are loose. The surface texture as well as figure accuracy and PSD1 (power spectrum density) of potassium dihydrogen phosphate (KDP) is greatly improved after MRF, which clearly prove the feasibility of substituting CIP and abrasive with Fe3O4 in our novel MRF design.

  5. The Magnetorheological Finishing (MRF) of Potassium Dihydrogen Phosphate (KDP) Crystal with Fe3O4 Nanoparticles.

    Science.gov (United States)

    Ji, Fang; Xu, Min; Wang, Chao; Li, Xiaoyuan; Gao, Wei; Zhang, Yunfei; Wang, Baorui; Tang, Guangping; Yue, Xiaobin

    2016-12-01

    The cubic Fe3O4 nanoparticles with sharp horns that display the size distribution between 100 and 200 nm are utilized to substitute the magnetic sensitive medium (carbonyl iron powders, CIPs) and abrasives (CeO2/diamond) simultaneously which are widely employed in conventional magnetorheological finishing fluid. The removal rate of this novel fluid is extremely low compared with the value of conventional one even though the spot of the former is much bigger. This surprising phenomenon is generated due to the small size and low saturation magnetization (M s) of Fe3O4 and corresponding weak shear stress under external magnetic field according to material removal rate model of magnetorheological finishing (MRF). Different from conventional D-shaped finishing spot, the low M s also results in a shuttle-like spot because the magnetic controllability is weak and particles in the fringe of spot are loose. The surface texture as well as figure accuracy and PSD1 (power spectrum density) of potassium dihydrogen phosphate (KDP) is greatly improved after MRF, which clearly prove the feasibility of substituting CIP and abrasive with Fe3O4 in our novel MRF design. PMID:26858161

  6. A selective nanocatalyst for an efficient Ugi reaction: Magnetically recoverable Cu(acac)2/NH2-T/SiO2@Fe3O4 nanoparticles

    Indian Academy of Sciences (India)

    Monireh Ghavami; Maryam Koohi; Mohammad Zaman Kassaee

    2013-11-01

    A novel, magnetically recoverable nanocatalyst is fabricated through simple immobilization of copper(II) acetylacetonate on the surface of amine-terminated silica-coated Fe3O4 nanoparticles: Cu(acac)2/NH2-T/SiO2@Fe3O4NPs. Unambiguous bonding of Cu to the terminal amine is indicated by Xray photoelectron spectroscopy (XPS). Further characterizations are carried out by different techniques. Selectivity of this catalyst is demonstrated through one-pot synthesis of fourteen α-aminoacyl amides using Ugi four-component reaction of cyclohexyl isocyanide, acetic acid, amines and various aldehydes. Interestingly, all aromatic aldehydes react with short reaction times and high yields, but heteroaromatic aldehydes do not yield any product. Catalyst efficiency remains unaltered through three consecutive experiments.

  7. Micro-optical coherence tomography tracking of magnetic gene transfection via Au-Fe3O4 dumbbell nanoparticles

    Science.gov (United States)

    Shi, Wei; Liu, Xinyu; Wei, Chao; Xu, Zhichuan J.; Sim, Stanley Siong Wei; Liu, Linbo; Xu, Chenjie

    2015-10-01

    Heterogeneous Au-Fe3O4 dumbbell nanoparticles (NPs) are composed of Au NPs and Fe3O4 NPs that bring in optical and magnetic properties respectively. This article reports the engineering of Au-Fe3O4 NPs as gene carriers for magnetic gene transfection as well as contrast agents for micro-optical coherence tomography (μOCT). As a proof-of-concept, Au-Fe3O4 NPs are used to deliver the green fluorescent protein to HEK 293T cells and their entrance into the cells is monitored through μOCT.Heterogeneous Au-Fe3O4 dumbbell nanoparticles (NPs) are composed of Au NPs and Fe3O4 NPs that bring in optical and magnetic properties respectively. This article reports the engineering of Au-Fe3O4 NPs as gene carriers for magnetic gene transfection as well as contrast agents for micro-optical coherence tomography (μOCT). As a proof-of-concept, Au-Fe3O4 NPs are used to deliver the green fluorescent protein to HEK 293T cells and their entrance into the cells is monitored through μOCT. Electronic supplementary information (ESI) available. See DOI: 10.1039/c5nr05459a

  8. Preparation of multi-functionalized Fe3O4/Au nanoparticles for medical purposes.

    Science.gov (United States)

    del Mar Ramos-Tejada, María; Viota, Julian L; Rudzka, Katarzyna; Delgado, Angel V

    2015-04-01

    In this work, we investigate a route towards the synthesis of multi-functionalized nanoparticles for medical purposes. The aim is to produce magnetite/gold (Fe3O4/Au) nanoparticles combining several complementary properties, specifically, being able to carry simultaneously an antitumor drug and a selected antibody chosen so as to improve specificity of the drug vehicle. The procedure included, firstly, the preparation of Fe3O4 cores coated with Au nanoparticles: this was achieved by using initially the layer-by-layer technique in order to coat the magnetite particles with a three polyelectrolyte (cationic-anionic-cationic) layer. With this, the particles became a good substrate for the growth of the gold layer in a well-defined core-shell structure. The resulting nanoparticles benefit from the magnetic properties of the magnetite and the robust chemistry and the biostability of gold surfaces. Subsequently, the Fe3O4/Au nanoparticles were functionalized with a humanized monoclonal antibody, bevacizumab, and a chemotherapy drug, doxorubicin. Taken together, bevacizumab enhances the therapeutic effect of chemotherapy agents on some kinds of tumors. In this work we first discuss the morphology of the particles and the electrical characteristics of their surface in the successive synthesis stages. Special attention is paid to the chemical stability of the final coating, and the physical stability of the suspensions of the nanoparticles in aqueous solutions and phosphate buffer. We describe how optical absorbance and electrokinetic data provide a follow up of the progress of the nanostructure formation. Additionally, the same techniques are employed to demonstrate that the composite nanoparticles are capable of loading/releasing doxorubicin and/or bevacizumab.

  9. Fe3O4 nanoparticles and nanocomposites with potential application in biomedicine and in communication technologies: Nanoparticle aggregation, interaction, and effective magnetic anisotropy

    Science.gov (United States)

    Allia, P.; Barrera, G.; Tiberto, P.; Nardi, T.; Leterrier, Y.; Sangermano, M.

    2014-09-01

    Magnetite nanoparticles with a size of 5-6 nm with potential impact on biomedicine and information/communication technologies were synthesized by thermal decomposition of Fe(acac)3 and subsequently coated with a silica shell exploiting a water-in-oil synthetic procedure. The as-produced powders (comprised of either Fe3O4 or Fe3O4@silica nanoparticles) were mixed with a photocurable resin obtaining two magnetic nanocomposites with the same nominal amount of magnetic material. The static magnetic properties of the two nanopowders and the corresponding nanocomposites were measured in the 10 K-300 K temperature range. Magnetic measurements are shown here to be able to give unambiguous information on single-particle properties such as particle size and magnetic anisotropy as well as on nanoparticle aggregation and interparticle interaction. A comparison between the size distribution functions obtained from magnetic measurements and from TEM images shows that figures estimated from properly analyzed magnetic measurements are very close to the actual values. In addition, the present analysis allows us to determine the value of the effective magnetic anisotropy and to estimate the anisotropy contribution from the surface. The Field-cooled/zero field cooled curves reveal a high degree of particle aggregation in the Fe3O4 nanopowder, which is partially reduced by silica coating and strongly decreased by dissolution in the host polymer. In all considered materials, the nanoparticles are magnetically interacting, the interaction strength being a function of nanoparticle environment and being the lowest in the nanocomposite containing bare, well-separate Fe3O4 particles. All samples behave as interacting superparamagnetic materials instead of ideal superparamagnets and follow the corresponding scaling law.

  10. Preparation of Fe3O4 magnetic nanoparticles coated with gallic acid for drug delivery

    Directory of Open Access Journals (Sweden)

    Dorniani D

    2012-11-01

    Full Text Available Dena Dorniani,1 Mohd Zobir Bin Hussein,1,2 Aminu Umar Kura,3 Sharida Fakurazi,3 Abdul Halim Shaari,4 Zalinah Ahmad51Chemistry Department, Faculty of Science, 2Advanced Materials and Nanotechnology Laboratory, Institute of Advanced Technology, 3Vaccines and Immunotherapeutics Laboratory, 4Physics Department, Faculty of Science, 5Chemical Pathology Unit, Department of Pathology, Faculty of Medicine and Health Sciences, Universiti Putra Malaysia, Selangor, MalaysiaBackground and methods: Magnetic iron oxide nanoparticles were prepared using a sonochemical method under atmospheric conditions at a Fe2+ to Fe3+ molar ratio of 1:2. The iron oxide nanoparticles were subsequently coated with chitosan and gallic acid to produce a core-shell structure.Results: X-ray diffraction demonstrated that the magnetic nanoparticles were pure Fe3O4 with a cubic inverse spinel structure. Transmission electron microscopy showed that the Fe3O4 nanoparticles were of spherical shape with a mean diameter of 11 nm, compared with 13 nm for the iron oxide-chitosan-gallic acid (FCG nanocarriers.Conclusion: The magnetic nanocarrier enhanced the thermal stability of the drug, gallic acid. Release of the active drug from the FCG nanocarrier was found to occur in a controlled manner. The gallic acid and FCG nanoparticles were not toxic in a normal human fibroblast (3T3 line, and anticancer activity was higher in HT29 than MCF7 cell lines.Keywords: magnetic nanoparticles, chitosan, superparamagnetic, controlled-release, gallic acid, drug delivery

  11. Gum arabic modified Fe3O4 nanoparticles cross linked with collagen for isolation of bacteria

    Directory of Open Access Journals (Sweden)

    Chittor Raghuraman

    2010-12-01

    Full Text Available Abstract Background Multifunctional magnetic nanoparticles are important class of materials in the field of nanobiotechnology, as it is an emerging area of research for material science and molecular biology researchers. One of the various methods to obtain multifunctional nanomaterials, molecular functionalization by attaching organic functional groups to nanomagnetic materials is an important technique. Recently, functionalized magnetic nanoparticles have been demonstrated to be useful in isolation/detection of dangerous pathogens (bacteria/viruses for human life. Iron (Fe based material especially FePt is used in the isolation of ultralow concentrations (2 cfu/ml of bacteria in less time and it has been demonstrated that van-FePt may be used as an alternative fast detection technique with respect to conventional polymerase chain reaction (PCR method. However, still further improved demonstrations are necessary with interest to biocompatibility and green chemistry. Herein, we report the synthesis of Fe3O4 nanoparticles by template medication and its application for the detection/isolation of S. aureus bacteria. Results The reduction of anhydrous Iron chloride (FeCl3 in presence of sodium borohydride and water soluble polyelectrolyte (polydiallyldimethyl ammonium chloride, PDADMAC produces black precipitates. The X-ray diffraction (XRD, XPS and TEM analysis of the precipitates dried at 373 K demonstrated the formation of nanocrystalline Fe3O4. Moreover, scanning electron microscopy (SEM showed isolated staphylococcous aureus (S. aureus bacteria at ultralow concentrations using collagen coated gum arabic modified iron oxide nanoparticles (CCGAMION. Conclusion We are able to synthesize nanocrystalline Fe3O4 and CCGAMION was able to isolate S. aureus bacteria at 8-10 cfu (colony forming units/ml within ~3 minutes.

  12. Study on Electromagnetorheological Fluid Containing CuPc-Fe3O4 Nanoparticles Composite

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    Electromagnetorheological(EMR) fluids containing CuPc-Fe3O4 nanopareticles composite were prepared and their properties were studied.The results show that Δτ of this kind of EMR fluids increases with the increments of applied electric field, magnetic field and volume fraction of the nanoparticles composite. Δτ has an approximate linear relationship with γ.When an electric and magnetic field are applied simultaneously,the EMR fluids have a synergistic effect. The EMR fluids have a good long-term stability.

  13. Ferroic ordering and charge-spin-lattice order coupling in Gd doped Fe3O4 nanoparticles

    Science.gov (United States)

    Laha, Suvra; Abdelhamid, Ehab; Palihawadana Arachchige, Maheshika; Dixit, Ambesh; Lawes, Gavin; Naik, Vaman; Naik, Ratna

    Rare earth doped spinels have been extensively studied for their potential applications in magneto-optical recording and as MRI contrast agents. In the present study, we have investigated the effect of gadolinium doping (1-5 at.%) on the magnetic and dielectric properties of Fe3O4nanoparticles synthesized by the chemical co-precipitation method. The structure and morphology of the as-synthesized gadolinium doped Fe3O4(Gd-Fe3O4) nanoparticles were characterized by XRD, SEM and TEM, and the magnetic properties were measured by a Quantum Design physical property measurement system. We find that the penetration of excess Gd3+ ions into Fe3O4 spinel matrix significantly influences the average crystallite size and saturation magnetization in Gd-Fe3O4. The average crystallite size, estimated from XRD using Scherrer equation, increases with increasing Gd doping percentage and the saturation magnetization drops monotonically with excess Gd3+ ions. Interestingly, Gd- Fe3O4develops enhanced ferroelectric ordering at low temperatures. The details of the temperature dependent dielectric, ferroelectric and magnetocapacitance measurements to understand the onset of charge-spin-lattice coupling in Gd-Fe3O4 system will be presented.

  14. Efficient purification of lysozyme from egg white by 2-mercapto-5-benzimidazolesulfonic acid modified Fe3O4/Au nanoparticles.

    Science.gov (United States)

    Zhu, Xinjun; Zhang, Lianying; Fu, Aiyun; Yuan, Hao

    2016-02-01

    2-Mercapto-5-benzimidazolesulfonic acid (MBISA) modified Fe3O4/Au nanoparticles were synthesized in aqueous solution and characterized by photo correlation spectroscopy (PCS) and vibrating sample magnetometer (VSM). The so-obtained Fe3O4/Au-MBISA nanoparticles were capable of specific adsorbing lysozyme. The maximum amount of lysozyme adsorbed on 1.0mg Fe3O4/Au-MBISA nanoparticles was 346μg. The lysozyme desorption behavior was studied and the lysozyme recovery from Fe3O4/Au-MBISA nanoparticles approached 100% under optimal conditions, and the reusability studies showed that the nanoparticles could maintain about 91% of the initial lysozyme adsorption capacity after 7 repeated adsorption-elution cycles. The Fe3O4/Au-MBISA nanoparticles were used in the purification of lysozyme from chicken egg white, which was verified by a single SDS-PAGE band. Therefore, the obtained Fe3O4/Au-MBISA nanoparticles exhibited excellent performance in the direct purification of lysozyme from egg white.

  15. Multifunctional polypyrrole@fe3o4 nanoparticles for dual-modal imaging and in vivo photothermal cancer therapy

    KAUST Repository

    Tian, Qiwei

    2013-11-27

    Magnetic Fe3O4 crystals are produced in situ on preformed polypyrrole (PPY) nanoparticles by rationally converting the residual Fe species in the synthetic system. The obtained PPY@Fe3O4 composite nanoparticles exhibit good photostability and biocompatibility, and they can be used as multifunctional probes for MRI, thermal imaging, and photothermal ablation of cancer cells. © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  16. Ethylene glycol methacrylate phosphate coated Fe3O4 nanoparticles for selective separation of plutonium

    International Nuclear Information System (INIS)

    Recovery of lanthanides and actinides from high level nuclear waste is an area of world-wide concern. Recently, interest has been focused on magnetic fluidized bed separation technology and the development of magnetically assisted chemical separation (MACS) systems for nuclear waste remediation. The magnetic-sorbent have larger surface area, can be quickly recovered from the medium using external magnetic field, and secondary waste is not generated. However, sorption selectivity and efficiency of these materials towards targeted radionuclides have still scope for improvement. Ethylene glycol methacrylate phosphate takes up actinides. Yudhisthira Sahoo and co-workers demonstrates that alkyl phosphonates and phosphates bind efficiently to iron oxide particle surfaces and can serve, in general, as potential alternatives to fatty acids as coating agents for oxide nanoparticles. In the present work, 0.1 g of Fe3O4 nanoparticles (20-30 nm) were dispersed in 10 mL 0.1 M Ethylene glycol methacrylate phosphate (EGMP) solution in methanol at room temperature under shaking condition for 24 h. Organic layer is then removed and the particles were washed 3 times with 1 mL methanol. It was the dried in air at room temperature overnight. Weighed amount of EGMP coated Fe3O4 nanoparticles were equilibrated with 241Am, 233U or 239Pu activity spiked in feed having acid concentration varying from 0.01-3.0 M HNO3

  17. Water dispersible oleic acid-coated Fe3O4 nanoparticles for biomedical applications

    Science.gov (United States)

    Shete, P. B.; Patil, R. M.; Tiwale, B. M.; Pawar, S. H.

    2015-03-01

    Fe3O4 magnetic nanoparticles (MNPs) have proved their tremendous potential to be used for various biomedical applications. Oleic acid (OA) is widely used in ferrite nanoparticle synthesis because it can form a dense protective monolayer, thereby producing highly uniform and monodispersed particles. Capping agents such as oleic acid are often used because they form a protective monolayer, which is strongly bonded to the surface of nanoparticles. This is necessary for making monodisperse and highly uniform MNPs. Coating of Fe3O4 MNPs with OA makes the particles dispersible only in organic solvents and consequently limits their use for biomedical applications. Hence, in this work, the OA coated MNPs were again functionalized with chitosan (CS), in order to impart hydrophilicity on their surface. All the morphological, magnetic, colloidal and cytotoxic characteristics of the resulting core-shells were studied thoroughly. Their heating induction ability was studied to predict their possible use in hyperthermia therapy of cancer. Specific absorption rate was found to be increased than that of bare MNPs.

  18. Interface composition between Fe3O4 nanoparticles and GaAs for spintronic applications

    Science.gov (United States)

    Hihath, Sahar; Kiehl, Richard A.; Benthem, Klaus van

    2014-08-01

    Recent interest in spintronic applications has necessitated the study of magnetic materials in contact with semiconductor substrates; importantly, the structure and composition of these interfaces can influence both device functionality and the magnetic properties. Nanoscale ferromagnet/semiconductor structures are of particular interest. In this study, the interface structure between a monolayer of ferromagnetic magnetite (Fe3O4) nanoparticles and a GaAs substrate was studied using cross-sectional transmission electron microscopy techniques. It was found that a continuous amorphous oxide interface layer separates the nanoparticles from the GaAs substrate, and that iron diffused into the interface layer forming a compositional gradient. Electron energy-loss near-edge fine structures of the O K absorption edge revealed that the amorphous oxide is composed of γ-Fe2O3 directly underneath the Fe3O4 nanoparticles, followed by a solid solution of Ga2O3 and FeO and mostly Ga2O3 when approaching the buckled oxide/substrate interface. Real-space density functional theory calculations of the dynamical form factor confirmed the experimental observations. The implication of the findings on the optimization of these structures for spin injection is discussed.

  19. The Preparation of Glucan-Fe3O4 Magnetic Nanoparticles and Its In Vivo Distribution in Mice

    Directory of Open Access Journals (Sweden)

    Fengdan Jin

    2014-01-01

    Full Text Available The glucan-Fe3O4 magnetic nanoparticles were prepared by hydrothermal method. The mixture of FeCl2 and glucan was stirred vigorously for half an hour under low temperature (15°C. KOH of 1 mol/L was dropwise added, slowly, into the solution until the pH to 12. Immediately, KNO3 was added and the temperature was raised to 75°C for an hour. All the processes of Fe3O4 crystal particles generation were under nitrogen. An atomic absorption spectrometry quantitative analysis method was built to determine the in vivo distribution of the glucan-Fe3O4 magnetic nanoparticles in mice. The diameter of glucan-Fe3O4 magnetic nanoparticles was about 25 nm and they were up taken by the liver primarily after intravenous administration via the tail.

  20. Fabrication of Docetaxel Surfaced Fe3O4 Magnetite Nanoparticles and their Cytotoxicity on 4 T1 Breast Cancer Cells

    Directory of Open Access Journals (Sweden)

    MH Yazdi

    2012-08-01

    Full Text Available Background:In the recent years, there is an increasing attention to the using of Fe3O4 magnetite nanoparticles (MNPs as drug delivery systems. Application of this nanoparticles could profit advantages of nanomedicine to enhance biological activity of pharmaceutical ingredients. Methods:Fe3O4 MNPs were synthesised by a chemical method and characterized by transmission electron microscopy and energy-dispersive spectroscopy techniques. In the next step, docetaxel-coated Fe3O4 MNPs were prepared, using percipitation method. The surface chemistry of docetaxel-coated Fe3O4 MNPs as well as their thermal decomposition characteristics were examined using fourier transform infrared spectroscopy and thermogravimetric analyzer equipment, respectively. The cytotoxicity assay was conducted on 4 T1 breast cancer carsinoma by MTT assay to evaluate the possible in vitro antiproliferative effects of docetaxel-coated Fe3O4 MNPs. Results:During precipitation process, docetaxel molecules were precipitated on the surface of Fe3O4 MNPs by the ratio of 3:100 w/w which indicates that each milligram of coated Fe3O4 MNPs averagely contained 30 mug pure docetaxel compound. Docetaxel showed aniproliferative effects against mentioned cell line. The higestest concentartion of docetaxel (80 mug/ml caused about 80% cell death. However, the results demostarted that much lower amounts of docetaxel will be needed in combination of Fe3O4 MNPs to produce the potent antiproliferative effect compared to docetaxel alone. Dose response cytotoxicity assay of docetaxel-coated Fe3O4 MNPs against 4 T1 breast cancer cells showed that lower amount of docetaxel (0.6 mug/ml can exhibit higher cytotoxic effect against this cancer cell line (90% cell death.

  1. In situ anchor of magnetic Fe3O4 nanoparticles onto natural maifanite as efficient heterogeneous Fenton-like catalyst

    Science.gov (United States)

    Zhao, Hang; Weng, Ling; Cui, Wei-Wei; Zhang, Xiao-Rui; Xu, Huan-Yan; Liu, Li-Zhu

    2016-09-01

    In situ anchor of magnetic Fe3O4 nanoparticles (NPs) onto the surface of natural maifanite was realized by chemical oxidation coprecipitation in hot alkaline solution. The Fe3O4/maifanite composites were characterized by XRD, FTIR, SEM, and TEM. These results indicated that polycrystalline Fe3O4 NPs with inverse spinel structure were formed and tightly dispersed on maifanite surface. Based on the measurement of surface Zeta potential of maifanite at different medium pHs, the possible combination mechanism between natural maifanite and Fe3O4 NPs was proposed. Then, the asobtained composites were developed as highly efficient heterogeneous Fenton-like catalyst for the discoloration of an azo dye, Methyl Orange (MO). The comparative tests on MO discoloration in different systems revealed that Fe3O4/maifanite composite exhibited much higher Fenton-like catalytic activity than Fe3O4 NPs and the heterogeneous Fentonlike reaction governed the discoloration of MO. Kinetic results clearly showed that MO discoloration process followed the second-order kinetic model. Fe3O4/maifanite composites exhibited the typical ferromagnetic property detected by VSM and could be easily separated from solution by an external magnetic field.

  2. Glucose sensor based on Fe3 O4-PEI nanoparticles%基于Fe3 O4-PEI纳米粒子构建葡萄糖传感器的研究

    Institute of Scientific and Technical Information of China (English)

    何传新; 任圣颖; 谢敏随; 袁安朋; 洪飞; 张黔玲; 刘剑洪

    2015-01-01

    Fe3O4-PEI nanoparticles with Fe3O4 core and polyethylenimine (PEI) shell were prepared via the co-precipitation method. Results from scanning electron microscope ( SEM ) and transmission electron microscope ( TEM) show that Fe3 O4-PEI nanoparticles present globular shape with almost uniform diameters of about 25 nm. Magnetic hysteresis loops of Fe3 O4-PEI and Fe3 O4 nanoparticles were obtained by a vibrating sample magnetometer ( VSM) . The magnetism of Fe3 O4 nanoparticles still remains a lot after coating with PEI, and the saturation magneti-zation value of Fe3 O4-PEI nanoparticles is 38. 2 emu/g. Thermogravimetry ( TG) analysis indicats that the loading amount of PEI on the surface of Fe3 O4 nanoparticles is about 23. 26%. The glucose oxidase ( GOx) enzyme was im-mobilized on the Fe3 O4-PEI nanoparticles surface by electrostatic interaction. Fe3 O4-PEI-GOx/Pt glucose sensor was prepared with platinum ( Pt) as its basal electrode, which exhibits a good electrochemical catalysis for glucose, high sensitivity, strong anti-interference ability and long-term durability for glucose detection under an optimal preparation condition.%采用共沉淀法制备核层为四氧化三铁( Fe3 O4)壳层为聚乙烯亚胺( polyethyleneimine, PEI)的磁性复合纳米粒子Fe3 O4-PEI.扫描电子显微镜和透射电子显微镜表征结果显示,制备的磁性复合纳米粒子Fe3 O4-PEI粒径均匀,直径约为25 nm.通过振动样品磁强计比较Fe3 O4-PEI和Fe3 O4纳米粒子的磁滞回线,结果表明,经PEI包覆后复合纳米粒子饱和磁化值为38.2 emu/g,仍具有较好的磁性.热重分析表明,包覆在Fe3 O4纳米粒子表面的PEI质量分数约为23.26%.通过静电作用,实现了Fe3 O4-PEI复合纳米粒子对葡萄糖氧化酶的负载,以铂电极为基底电极,制备了Fe3 O4-PEI-GOx/Pt葡萄糖传感器.在最优测试条件下,该修饰电极对葡萄糖表现出优异的电化学催化性能,具有灵敏度高、抗干扰能力强、稳定性好的特点.

  3. Contribution of Fe3O4 nanoparticles to the fouling of ultrafiltration with coagulation pre-treatment

    Science.gov (United States)

    Yu, Wenzheng; Xu, Lei; Graham, Nigel; Qu, Jiuhui

    2015-08-01

    A coagulation (FeCl3)-ultrafiltration process was used to treat two different raw waters with/without the presence of Fe3O4 nanoparticle contaminants. The existence of Fe3O4 nanoparticles in the raw water was found to increase both irreversible and reversible membrane fouling. The trans-membrane pressure (TMP) increase was similar in the early stages of the membrane runs for both raw waters, while it increased rapidly after about 15 days in the raw water with Fe3O4 nanoparticles, suggesting the involvement of biological effects. Enhanced microbial activity with the presence of Fe3O4 nanoparticles was evident from the measured concentrations of extracellular polymeric substances (EPS) and deoxyribonucleic acid (DNA), and fluorescence intensities. It is speculated that Fe3O4 nanoparticles accumulated in the cake layer and increased bacterial growth. Associated with the bacterial growth is the production of EPS which enhances the bonding with, and between, the coagulant flocs; EPS together with smaller sizes of the nano-scale primary particles of the Fe3O4-CUF cake layer, led to the formation of a lower porosity, more resilient cake layer and membrane pore blockage.

  4. Alpha chymotrypsin coated clusters of Fe3O4 nanoparticles for biocatalysis in low water media

    Directory of Open Access Journals (Sweden)

    Mukherjee Joyeeta

    2012-11-01

    Full Text Available Abstract Background Enzymes in low water containing non aqueous media are useful for organic synthesis. For example, hydrolases in such media can be used for synthetic purposes. Initial work in this area was carried out with lyophilized powders of enzymes. These were found to have poor activity. Drying (removing bulk water by precipitation turned out to be a better approach. As enzymes in such media are heterogeneous catalysts, spreading these precipitates over a large surface gave even better results. In this context, nanoparticles with their better surface to volume ratio provide obvious advantage. Magnetic nanoparticles have an added advantage of easy separation after the reaction. Keeping this in view, alpha chymotrypsin solution in water was precipitated over a stirred population of Fe3O4 nanoparticles in n-propanol. This led to alpha chymotrypsin activity coated over clusters of Fe3O4 nanoparticles. These preparations were found to have quite high transesterification activity in low water containing n-octane. Results Precipitation of alpha chymotrypsin over a stirred suspension of Fe3O4 nanoparticles (3.6 nm diameter led to the formation of enzyme coated clusters of nanoparticles (ECCNs. These clusters were also magnetic and their hydrodynamic diameter ranged from 1.2- 2.6 microns (as measured by dynamic light scattering. Transmission electron microscopy (TEM, showed that these clusters had highly irregular shapes. Transesterification assay of various clusters in anhydrous n-octane led to optimization of concentration of nanoparticles in suspension during precipitation. Optimized design of enzyme coated magnetic clusters of nanoparticles (ECCN 3 showed the highest initial rate of 465 nmol min-1 mg-1protein which was about 9 times higher as compared to the simple precipitates with an initial rate of 52 nmol min-1 mg-1 protein. Circular Dichroism (CD(with a spinning cell accessory showed that secondary structure content of the alpha

  5. Magnetic Behaviour and Heating Effect of Fe3O4 Ferrofluids Composed of Monodisperse Nanoparticles

    Institute of Scientific and Technical Information of China (English)

    ZHANG Li-Ying; DOU Yong-Hua; ZHANG Ling; GU Hong-Chen

    2007-01-01

    Fe3O4 ferrofluids containing monodisperse Fe3O4 nanoparticles with different diameters of 8, 12, 16 and 18 nm are prepared by using high-temperature solution phase reaction. The particles have single crystal structures with narrow size distributions. At room temperature, the 8-nm ferrofluid shows superparamagnetic behaviour,whereas the others display hysteresis properties and the coercivity increases with the increasing particle size.The spin glass-like behaviour and cusps near 190K are observed on all ferrofluids according to the temperature variation of field-cooled (FC) and zero-field-cooled (ZFC) magnetization measurements. The cusps are found to be associated with the freezing point of the solvent. As a comparison, the ferrofluids are dried and the FC and ZFC magnetization curves of powdery samples are also investigated. It is found that the blocking temperatures for the powdery samples are higher than those for their corresponding ferrofluids. Moreover, the size dependent heating effect of the ferrofluids is also investigated in ac magnetic field with a frequency of 55 kHz and amplitude of 200 Oe.

  6. Linear birefringence and dichroism measurement in oil-based Fe3O4 magnetic nanoparticles

    Science.gov (United States)

    Lin, Jing-Fung; Wang, Chia-Hung; Lee, Meng-Zhe

    2013-04-01

    To prepare dispersed Fe3O4 magnetic nanoparticles (MNPs), we adopt a co-precipitation method and consider surfactant amount, stirring speed, dispersion mode, and molar ratio of Fe3+/Fe2+. Via transmission electronic microscopy and X-ray diffractometry, we characterize the dispersibility and size of the products and determine the appropriate values of experimental parameters. The stirring speed is 1000 rpm in titration. There is simultaneous ultrasonic vibration and mechanical stirring in the titration and surface coating processes. The surfactant amount of oleic acid is 1.2 ml for molar ratios of Fe3+/Fe2+ as 1.7:1, 1.8:1, and 1.9:1. The average diameters of these Fe3O4 MNPs are 11 nm, and the ratios of saturation magnetization for these MNPs to that of bulk magnetite range from 45% to 65%, with remanent magnetization close to zero and low coercivity. Above all, the linear birefringence and dichroism measurements of the kerosene-based ferrofluid (FF) samples are investigated by a Stokes polarimeter. The influences of particle size distribution and magnetization in the birefringence and dichroism measurements of FFs are discussed.

  7. Preparation and superparamagnetism of Fe3O4 nanoparticles%Fe3O4纳米粒子的制备与超顺磁性

    Institute of Scientific and Technical Information of China (English)

    秦润华; 姜炜; 刘宏英; 李凤生

    2007-01-01

    采用红外光谱、X射线衍射、透射电子显微镜和振动样品磁强计对用化学共沉淀法制备出的纳米Fe3O4粒子进行了形貌、结构及磁性能表征.其中,红外和XRD测试结果表明制备出的Fe3O4粒子的物态和晶相结构;透射电子显微镜照片表明制备出的纳米四氧化三铁成球性好,且大部分四氧化三铁粒子的粒径在10nm左右;磁化曲线表明制备出的Fe3O4粒子无剩磁和矫顽力,具有超顺磁性.并且,将制备出的纳米Fe3O4粒子和块状Fe3O4的磁性能进行对比,探讨了Fe3O4由块状的亚铁磁性向纳米级的超顺磁性转变的原因.

  8. 包覆层厚度对 Fe3O4@SiO2核壳结构纳米粒子磁共振性能的影响%The effect of coating thickness on the magnetic resonance imaging properties of Fe3O4@SiO2 core-shall structured nanoparticles

    Institute of Scientific and Technical Information of China (English)

    万家齐; 陈克正; 王书宪

    2015-01-01

    Silica coated core-shell structured magnetite nanoparticles have great potential in diverse biomedical applications.In this paper,water-soluble monodisperse Fe3 O4 nanoparticles as cores were prepared by polyol process.The silica coating was deposited on the surface of the Fe3 O4 nanoparticles via hydrolysis of silicon powder.The thickness of silica coating layer was adjusted by changing the mass of silicon powder in the reaction system.Finally,the proton relaxation properties of Fe3 O4 @SiO2 nanoparti-cles with various coating thickness were investigated.It was found that the transverse relaxation rate was reduced as the thickness of SiO2 coating increases.The decrease in relaxivity is attributed to the increased distance between water molecules and magnetic core.%二氧化硅包覆四氧化三铁核壳结构纳米粒子在生物医学领域有着广泛的用途。本文采用单质硅粉水解法,以单分散水溶性 Fe3 O4纳米粒子为内核,通过改变反应体系中单质硅粉的加入质量,制备了不同包覆厚度的 Fe3 O4@SiO2纳米粒子,并对SiO2包覆层厚度对 Fe3 O4纳米粒子磁共振性能的影响进行了研究。结果表明:随着 SiO2壳层厚度的增加,横向弛豫效率 r2逐渐降低。弛豫效率降低是由水分子与磁性纳米粒子内核之间的距离逐渐增大引起的。

  9. The effect of Fe3O4 nanoparticles on the thermal conductivities of various base fluids.

    Science.gov (United States)

    Altan, Cem L; Bucak, Seyda

    2011-07-15

    Conventional heat transfer fluids have intrinsically poor heat transfer properties compared to solids. Enhancing the efficiency of heat transfer is of great interest for various industrial applications. Suspending solid particles in a fluid increases the thermal conductivity of the resulting suspension and enhances the heat transfer properties. In this work, changes in thermal conductivities of fluids upon the addition of magnetic nanoparticles have been investigated. Fe(3)O(4) nanoparticles are synthesized using different synthesis methods and are suspended in various oils. The effect of the base fluid and the type of magnetic particle on the thermal conductivity is investigated in detail. Up to 28% increase in the thermal conductivity is obtained with 2.5 wt% magnetic particles in hexane. The thermal conductivity enhancement is found to depend on the particle concentration, method of preparation and base fluid. The enhancements obtained are higher than those estimated using any theoretical model present in the literature. PMID:21659690

  10. The effect of Fe3O4 nanoparticles on the thermal conductivities of various base fluids

    Science.gov (United States)

    Altan, Cem L.; Bucak, Seyda

    2011-07-01

    Conventional heat transfer fluids have intrinsically poor heat transfer properties compared to solids. Enhancing the efficiency of heat transfer is of great interest for various industrial applications. Suspending solid particles in a fluid increases the thermal conductivity of the resulting suspension and enhances the heat transfer properties. In this work, changes in thermal conductivities of fluids upon the addition of magnetic nanoparticles have been investigated. Fe3O4 nanoparticles are synthesized using different synthesis methods and are suspended in various oils. The effect of the base fluid and the type of magnetic particle on the thermal conductivity is investigated in detail. Up to 28% increase in the thermal conductivity is obtained with 2.5 wt% magnetic particles in hexane. The thermal conductivity enhancement is found to depend on the particle concentration, method of preparation and base fluid. The enhancements obtained are higher than those estimated using any theoretical model present in the literature.

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

    Science.gov (United States)

    Echeverria, Coro; Mijangos, Carmen

    2011-07-01

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

  12. Exchange bias effect in Au-Fe3O4 dumbbell nanoparticles induced by the charge transfer from gold

    Energy Technology Data Exchange (ETDEWEB)

    Feygenson, Mikhail; Bauer, John C.; Gai, Zheng; Marques, Carlos; Aronson, Meigan C.; Teng, Xiaowei; Su, Dong; Stanic, Vesna; Urban, Volker S.; Beyer, Kevin A.; Dai, Sheng

    2015-08-10

    We have studied the origin of the exchange bias effect in the Au-Fe3O4 dumbbell nanoparticles in two samples with different sizes of the Au seed nanoparticles (4.1 and 2.7 nm) and same size of Fe3O4 nanoparticles (9.8 nm). The magnetization, small-angle neutron-scattering, synchrotron x-ray diffraction, and scanning transmission electron microscope measurements determined the antiferromagnetic FeO wustite phase within Fe3O4 nanoparticles, originating at the interface with the Au nanoparticles. The interface between antiferromagnetic FeO and ferrimagnetic Fe3O4 is giving rise to the exchange bias effect. The strength of the exchange bias fields depends on the interfacial area and lattice mismatch between both phases. We propose that the charge transfer from the Au nanoparticles is responsible for a partial reduction of the Fe3O4 into the FeO phase at the interface with Au nanoparticles. The Au-O bonds are formed, presumably across the interface to accommodate an excess of oxygen released during the reduction of magnetite

  13. Colorimetric aptasensing of ochratoxin A using Au@Fe3O4 nanoparticles as signal indicator and magnetic separator.

    Science.gov (United States)

    Wang, Chengquan; Qian, Jing; Wang, Kun; Yang, Xingwang; Liu, Qian; Hao, Nan; Wang, Chengke; Dong, Xiaoya; Huang, Xingyi

    2016-03-15

    Gold nanoparticles (Au NPs) doped Fe3O4 (Au@Fe3O4) NPs have been synthesized by a facile one-step solvothermal method. The peroxidase-like activity of Au@Fe3O4 NPs was effectively enhanced due to the synergistic effect between the Fe3O4 NPs and Au NPs. On this basis, an efficient colorimetric aptasensor has been developed using the intrinsic dual functionality of the Au@Fe3O4 NPs as signal indicator and magnetic separator. Initially, the amino-modified aptamer specific for a typical mycotoxin, ochratoxin A (OTA), was surface confined on the amino-terminated glass beads surafce using glutaraldehyde as a linker. Subsequently, the amino-modified capture DNA (cDNA) was labeled with the amino-functionalized Au@Fe3O4 NPs and the aptasensor was thus fabricated through the hybridization reaction between cDNA and the aptamers. While upon OTA addition, aptamers preferred to form the OTA-aptamer complex and the Au@Fe3O4 NPs linked on the cDNA were released into the bulk solution. Through a simple magnetic separation, the collected Au@Fe3O4 NPs can produce a blue colored solution in the presence of 3,3',5,5'-tetramethylbenzidine and H2O2. When the reaction was terminated by addition of H(+) ions, the blue product could be changed into a yellow one with higher absorption intensity. This colorimetric aptasensor can detect as low as 30 pgmL(-1) OTA with high specificity. To the best of our knowledge, the present colorimetric aptasensor is the first attempt to use the peroxidase-like activity of nanomaterial for OTA detection, which may provide an acttractive path toward routine quality control of food safety. PMID:26583358

  14. Preparation and photocatalytic properties of magnetically reusable Fe3O4@ZnO core/shell nanoparticles

    Science.gov (United States)

    Wang, Jian; Yang, Jinghai; Li, Xiuyan; Wang, Dandan; Wei, Bing; Song, Hang; Li, Xuefei; Fu, Siwei

    2016-01-01

    Fe3O4@ZnO binary nanoparticles were synthesized by a simple two-step chemical method and characterized using various analytical instruments. TEM result proved the binary nanoparticles have core/shell structures and average particle size is 60 nm. Photocatalytic investigation of Fe3O4@ZnO core/shell nanoparticles was carried out using rhodamine B (RhB) solution under UV light. Fe3O4@ZnO core/shell nanoparticles showed enhanced photocatalytic performance in comparison with the as prepared ZnO nanoparticles. The enhanced photocatalytic activity for Fe3O4@ZnO might be resulting from the higher concentration of surface oxygen vacancies and the suppressing effect of the Fe3+ ions on the recombination of photoinduced electron-hole pairs. Magnetization saturation value (5.96 emu/g) of Fe3O4@ZnO core/shell nanoparticles is high enough to be magnetically removed by applying a magnetic field. The core/shell photocatalyst can be easily separated by using a commercial magnet and almost no decrease in photocatalytic efficiency was observed even after recycling six times.

  15. Structural and magnetic properties of Fe3O4 nanoparticles prepared by arc-discharge in water

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    By using a simple and low-cost arc-discharge method in deionized water, high purity Fe3O4 nanoparticles have been synthesized on large scale. The structure of these nanoparticles has been studied by means of transmission electron microscope and X-ray diffraction. The synthesized Fe3O4 nanoparticles show well-defined spherical shape, with diameters ranging from 10 to 30 nm and the average diameter about 20 nm. By investigating the effects of the different processing conditions, optimum parameters were obtained. Moreover, the size of the as-grown nanoparticles can also be controlled through adjusting the processing parameters. These Fe3O4 nanoparticles were magnetic materials, showing saturation magnetization of 64.97 emu/g at room temperature.

  16. Functionalized Fe3O4@silica core-shell nanoparticles as microalgae harvester and catalyst for biodiesel production.

    Science.gov (United States)

    Chiang, Ya-Dong; Dutta, Saikat; Chen, Ching-Tien; Huang, Yu-Tzu; Lin, Kuen-Song; Wu, Jeffrey C S; Suzuki, Norihiro; Yamauchi, Yusuke; Wu, Kevin C-W

    2015-03-01

    Core-shell Fe3O4@silica magnetic nanoparticles functionalized with a strong base, triazabicyclodecene (TBD), were successfully synthesized for harvesting microalgae and for one-pot microalgae-to-fatty acid methyl ester (FAME, or so-called biodiesel) conversion. Three types of algae oil sources (i.e., dried algae, algae oil, and algae concentrate) were used and the reaction conditions were optimized to achieve the maximum biodiesel yield. The results obtained in this study show that our TBD-functionalized Fe3O4@silica nanoparticles could effectively convert algae oil to biodiesel with a maximum yield of 97.1 %. Additionally, TBD-Fe3O4@silica nanoparticles act as an efficient algae harvester because of their adsorption and magnetic properties. The method presented in this study demonstrates the wide scope for the use of covalently functionalized core-shell nanoparticles for the production of liquid transportation fuels from algal biomass.

  17. Fe_3O_4磁粉的合成与结构表征%Preparation of Fe3O4 Nanoparticle by Liquid - phase Coprecipitation

    Institute of Scientific and Technical Information of China (English)

    霍涌前; 陈小利; 王升文; 崔华莉; 王潇

    2012-01-01

    Nanometer magnetite Fe3O4 particles were prepared by chemical co -precipitation, NH3·H2O was cho- sen as precipitating agent and added to the mixed aqueous solution containing ferric and ferrous ions to produce nanometer Fe3O4 particles. Some influence factors on the size were investigated. The phase structure of the particle was measured by XRD test, and the average size was about 28 nm.%采用化学共沉淀法制备纳米磁性Fe3O4粒子。选用NH3.H2O作为沉淀剂,加入到Fe2+和Fe3+的混合盐溶液中,制得了纳米磁性Fe3O4粒子。考察了影响产物粒径的一些实验因素。通过X-Ray谱图证实了产物结构特征,平均粒径在37 nm左右,平均晶粒度只有28 nm左右的均分散。

  18. FMR Study of the Porous Silicate Glasses with Fe3O4 Magnetic Nanoparticles Fillers

    Directory of Open Access Journals (Sweden)

    B. Zapotoczny

    2012-01-01

    Full Text Available The results of research on new magnetic materials for biomedical applications are discussed. These materials are porous silicate glasses with magnetic fillers. To ensure the smallest number of components for subsequent removal from the body, the magnetic fillers are bare magnetite nanoparticles (Fe3O4. The magnetic properties of these materials have been investigated using the ferromagnetic resonance method (FMR. The FMR analysis has been complemented by scanning electron microscope (SEM measurements. In order to examine the effect of time degradation on filling the porous glass with bare magnetite nanoparticles the FMR measurement was repeated five months later. For the samples with high degree of pore filling, in contrast to the samples with low degree of pore filling, the FMR signal was still strong. The influence of different pH values of magnetite nanoparticles aqueous suspension on the degree of filling the pores of glasses is also discussed. The experimental results are supported by computer simulations of FMR experiment for a cluster of N magnetic nanoparticles locked in a porous medium based on a stochastic version of the Landau-Lifshitz equation for nanoparticle magnetization.

  19. Preparation of Fe3O4/TiO2 nanoparticles by microemulsion%微乳液法制备Fe3O4/TiO2磁性纳米粒子

    Institute of Scientific and Technical Information of China (English)

    杜雪岩; 马芬; 李芳; 徐凯; 史世毅

    2011-01-01

    The Fe3O4 magnetic nanoparticles with the average particle size of about 6.0 nm were prepared by a polyol reduction method.Fe3O4/TiO2 nanoparticles were synthesized in a OP-10/n-butanol/cyelohexane/ammonia reverse microemulsion system by using of as-prepared Fe3O4 nanoparticles as cores.The composite nanoparticles were characterized by X-ray powder diffraction (XRD) , transmission electron microscopy (TEM) ,and vibrating sample magnetometer ( VSM).The results showed that the primary titanium dioxide coated successfully on the surface of Fe3O4 nanoparticles.After coating performance, their saturation magnetization decreased significantly, while their coercivity was also close to zero indicating super-paramagnetic properties.%采用多元醇还原法制备出平均粒径为6.0 nm的Fe3O4磁性纳米粒子,以此磁性纳米粒子为核,在OP-10/正丁醇/环己烷/浓氨水反向微乳体系中制备出Fe3O4/TiO2磁性纳米复合粒子,通过XRD,TEM,VSM对复合籽子进行性能表征.结果表明,采用微乳液法能够制备出Fe3O4/TiO2磁性纳米复合粒子,并且包覆后比饱和磁化强度有所下降,但矫顽力仍趋近于0,显示超顺磁性.

  20. One-Pot Green Synthesis and Bioapplication of l-Arginine-Capped Superparamagnetic Fe3O4 Nanoparticles

    Science.gov (United States)

    Lai, Yongchao; Yin, Weiwei; Liu, Jinting; Xi, Rimo; Zhan, Jinhua

    2010-02-01

    Water-soluble l-arginine-capped Fe3O4 nanoparticles were synthesized using a one-pot and green method. Nontoxic, renewable and inexpensive reagents including FeCl3, l-arginine, glycerol and water were chosen as raw materials. Fe3O4 nanoparticles show different dispersive states in acidic and alkaline solutions for the two distinct forms of surface binding l-arginine. Powder X-ray diffraction and X-ray photoelectron spectroscopy were used to identify the structure of Fe3O4 nanocrystals. The products behave like superparamagnetism at room temperature with saturation magnetization of 49.9 emu g-1 and negligible remanence or coercivity. In the presence of 1-ethyl-3-(dimethylaminopropyl) carbodiimide hydrochloride, the anti-chloramphenicol monoclonal antibodies were connected to the l-arginine-capped magnetite nanoparticles. The as-prepared conjugates could be used in immunomagnetic assay.

  1. Fe3O4/Salicylic acid nanoparticles behavior on chick CAM vasculature

    International Nuclear Information System (INIS)

    A modified ferrite co-precipitation synthesis was used to obtain core–shell Fe3O4/salicylic acid magnetic nanoparticles (Sa-MNP) with well-dispersed aqueous solution properties. The newly developed iron oxide nanoparticles properties were investigated with X-ray diffraction, Fourier transform infrared spectrometry, transmission electron microscopy, and laser light scattering for their characteristic establishment. The resulting Sa-MNPs have spherical morphology, homogenous size distribution around 60 nm (35 nm FWHM), and a 67 mV Zeta potential value (15.5 mV STDV). In vivo biocompatibility and intravascular behavior of the 60 nm diameter size range synthesized nanoparticles were evaluated on chick chorioallantoic membrane model. The results show a reversible and good controlled intravascular accumulation under static magnetic field, a low risk of embolisation with nanoparticle aggregates detached from venous intravascular nanoblocked areas, a persistent blocking of the arterioles and dependent capillaries network, a good circulating life time and biocompatibility. The beneficial effects of salicylic acid (SA) and in vivo demonstrated capacity of Sa-MNPs to cutoff regional vascular supply under static magnetic field control suggest a possible biomedical application of these MNPs in targeted cancer therapy through magnetic controlled blood flow nanoblocking mechanism

  2. Preparation of nanosized hollow silica spheres from Na2SiO3 using Fe3O4 nanoparticles as templates

    Institute of Scientific and Technical Information of China (English)

    Chun Liu; Aili Wang; Hengbo Yin; Yutang Shen; Tingshun Jiang

    2012-01-01

    Nanosized hollow silica spheres with average diameters from 43 to 70nm were prepared by removal of Fe3O4 templates with hydrochloric acid from silica-coated Fe3O4 core-shell composites.The shells of the hollow silica spheres had nanopores with average diameters of 0.92-1.25 nm.When the silica-coated Fe3O4 core-shell composites were prepared at a high pH value or with a low mole ratio of Na2SiO3 to Fe3O4,the resulting hollow silica spheres consisted of highly porous shells.When the silica-coated Fe3O4 core-shell composites were prepared with a high mole ratio of Na2SiO3 to Fe3O4,the resulting hollow silica spheres had large diameters and thick shells.The release rate of herbicide,ammonium glyphosate,could be tuned by using hollow silica spheres with different shell thicknesses.

  3. Shape-Controllable Synthesis of Peroxidase-Like Fe3O4 Nanoparticles for Catalytic Removal of Organic Pollutants

    Science.gov (United States)

    Wan, Dong; Li, Wenbing; Wang, Guanghua; Wei, Xiaobi

    2016-10-01

    The shape of Fe3O4 nanoparticles is controlled using a simple oxidation-precipitation method without any surfactant. The morphology and structure of the obtained Fe3O4 nanoparticles were characterized by using x-ray diffraction, scanning electron microscopy, x-ray photoelectron spectroscopy, N2 physisorption and vibrating sample magnetometer. As-prepared Fe3O4 samples showed octahedron, cube, hexagonal plate and sphere morphologies. Peroxidase-like activity of the four nanostructures was evaluated for catalytic removal of organic pollutants in the presence of H2O2, using rhodamine B as a model compound. The results showed that the H2O2-activating ability of the Fe3O4 nanocrystals was structure dependent and followed the order sphere > cube > octahedron > hexagonal plate, which was closely related to their surface FeII/FeIII ratios or crystal planes. The reusability of Fe3O4 spheres was also investigated after five successive runs, which demonstrated the promising application of the catalyst in the degradation of organic pollutants. This investigation is of great significance for the heterogeneous catalysts with enhanced activity and practical application.

  4. Shape-Controllable Synthesis of Peroxidase-Like Fe3O4 Nanoparticles for Catalytic Removal of Organic Pollutants

    Science.gov (United States)

    Wan, Dong; Li, Wenbing; Wang, Guanghua; Wei, Xiaobi

    2016-08-01

    The shape of Fe3O4 nanoparticles is controlled using a simple oxidation-precipitation method without any surfactant. The morphology and structure of the obtained Fe3O4 nanoparticles were characterized by using x-ray diffraction, scanning electron microscopy, x-ray photoelectron spectroscopy, N2 physisorption and vibrating sample magnetometer. As-prepared Fe3O4 samples showed octahedron, cube, hexagonal plate and sphere morphologies. Peroxidase-like activity of the four nanostructures was evaluated for catalytic removal of organic pollutants in the presence of H2O2, using rhodamine B as a model compound. The results showed that the H2O2-activating ability of the Fe3O4 nanocrystals was structure dependent and followed the order sphere > cube > octahedron > hexagonal plate, which was closely related to their surface FeII/FeIII ratios or crystal planes. The reusability of Fe3O4 spheres was also investigated after five successive runs, which demonstrated the promising application of the catalyst in the degradation of organic pollutants. This investigation is of great significance for the heterogeneous catalysts with enhanced activity and practical application.

  5. A Facile Approach to Fabricate Water-soluble Au-Fe3O4 Nanoparticle for Liver Cancer Cells Imaging

    Institute of Scientific and Technical Information of China (English)

    梁重时; 吴献荣; 谢叶归; 刘顺英

    2012-01-01

    Au-Fe3O4 nanoparticles were widely used as nanoplatforms for biologic applications through readily further functionalization. Dopamine (DA)-coated superparamagnetic iron oxide (SPIO) nanoparticles (DA@Fe3O4) have been successfully synthesized using a one-step process by modified coprecipitation method. Then 2--3 nm gold nanoparticles were easily conjugated to DA@Fe3O4 nanoparticles by the electrostatic force between gold nanoparti- cles and amino groups of dopamine to afford water-soluble Au-Fe3O4 hybrid nanoparticles. A detailed investigation by dynamic light scatting (DLS), transmission electron microscopy (TEM), fourier transform infrared (FT-IR) and X-ray diffraction (XRD) were performed in order to characterize the physicochemical properties of the hybrid nanoparticles. The hybrid nanoparticles were easily functionalized with a targeted small peptide A54 (AGKGTPSLETTP) and fluorescence probe fluorescein isothiocyanate (FITC) for liver cancer cell BEL-7402 imaging. This simple approach to prepare hybrid nanoparticles provides a facile nanoplatform for muti-functional derivations and may be extended to the immobilization of other metals or bimolecular on SPIO surface.

  6. Fabrication highly dispersed Fe3O4 nanoparticles on carbon nanotubes and its application as a mimetic enzyme to degrade Orange II.

    Science.gov (United States)

    Deng, Jingheng; Wen, Xianghua; Li, Jiaxi

    2016-09-01

    Fe3O4 nanoparticles were grown in situ on carbon nanotubes (CNTs) by a solvothermal method. The Fe3O4/CNTs composites were characterised by the Brunauer-Emmett-Teller method and transmission electron microscopy. The results indicated that the Fe3O4 nanoparticles were uniformly deposited on CNTs, and the average diameter was approximately 7.0 nm. The Fe3O4/CNTs were applied as an enzyme mimetic to decompose Orange II, and the decomposing conditions were optimised. At 500 mg L(-1) of Fe3O4/CNTs in the presence of 15.0 mmol L(-1) of H2O2, at 30°C, it degraded 94.0% of Orange II (0.25 mmol L(-1), pH = 3.5), showing higher catalytic activity than pure Fe3O4 nanoparticles. The high activity was attributed to the uniform Fe3O4 nanoparticles growing on the side walls of the CNTs and the synergetic effect between Fe3O4 and CNTs. The Fe3O4/CNTs maintained their activity at temperatures as high as 65°C. The Fe3O4/CNTs presented high reusability and stability even after eight uses. These data proved that the Fe3O4/CNTs-catalysed degradation is a promising technique for wastewater treatment. Fe3O4 nanoparticles were grown in situ on carbon nanotubes (CNTs) by a solvothermal method. The Fe3O4/CNTs was applied as a mimetic enzyme to decompose Orange II. The Fe3O4/CNTs were collected after the reaction by applying an external magnetic field and can use repeatedly. PMID:26828855

  7. Multifunctional NaYF4:Yb, Er@mSiO2@Fe3O4-PEG nanoparticles for UCL/MR bioimaging and magnetically targeted drug delivery

    Science.gov (United States)

    Liu, Bei; Li, Chunxia; Ma, Ping'an; Chen, Yinyin; Zhang, Yuanxin; Hou, Zhiyao; Huang, Shanshan; Lin, Jun

    2015-01-01

    A low toxic multifunctional nanoplatform, integrating both mutimodal diagnosis methods and antitumor therapy, is highly desirable to assure its antitumor efficiency. In this work, we show a convenient and adjustable synthesis of multifunctional nanoparticles NaYF4:Yb, Er@mSiO2@Fe3O4-PEG (MFNPs) based on different sizes of up-conversion nanoparticles (UCNPs). With strong up-conversion fluorescence offered by UCNPs, superparamagnetism properties attributed to Fe3O4 nanoparticles and porous structure coming from the mesoporous SiO2 shell, the as-obtained MFNPs can be utilized not only as a contrast agent for dual modal up-conversion luminescence (UCL)/magnetic resonance (MR) bio-imaging, but can also achieve an effective magnetically targeted antitumor chemotherapy both in vitro and in vivo. Furthermore, the UCL intensity of UCNPs and the magnetic properties of Fe3O4 in the MFNPs were carefully balanced. Silica coating and further PEG modifying can improve the hydrophilicity and biocompatibility of the as-synthesized MFNPs, which was confirmed by the in vitro/in vivo biocompatibility and in vivo long-time bio-distributions tests. Those results revealed that the UCNPs based magnetically targeted drug carrier system we synthesized has great promise in the future for multimodal bio-imaging and targeted cancer therapy.A low toxic multifunctional nanoplatform, integrating both mutimodal diagnosis methods and antitumor therapy, is highly desirable to assure its antitumor efficiency. In this work, we show a convenient and adjustable synthesis of multifunctional nanoparticles NaYF4:Yb, Er@mSiO2@Fe3O4-PEG (MFNPs) based on different sizes of up-conversion nanoparticles (UCNPs). With strong up-conversion fluorescence offered by UCNPs, superparamagnetism properties attributed to Fe3O4 nanoparticles and porous structure coming from the mesoporous SiO2 shell, the as-obtained MFNPs can be utilized not only as a contrast agent for dual modal up-conversion luminescence (UCL

  8. Fe3O4/Au magnetic nanoparticle amplification strategies for ultrasensitive electrochemical immunoassay of alfa-fetoprotein

    Directory of Open Access Journals (Sweden)

    Gan N

    2011-12-01

    Full Text Available Ning Gan1*, Haijuan Jin1*, Tianhua Li1, Lei Zheng21The State Key Laboratory Base of Novel Functional Materials and Preparation Science, Faculty of Material Science and Chemical Engineering, Ningbo University, Ningbo, 2Department of Laboratory Medicine, Nanfang Hospital, Southern Medical University, Guangzhou, People's Republic of China *Both authors contributed equally to this workBackground: The purpose of this study was to devise a novel electrochemical immunosensor for ultrasensitive detection of alfa-fetoprotein based on Fe3O4/Au nanoparticles as a carrier using a multienzyme amplification strategy.Methods and results: Greatly enhanced sensitivity was achieved using bioconjugates containing horseradish peroxidase (HRP and a secondary antibody (Ab2 linked to Fe3O4/Au nanoparticles (Fe3O4/Au-HRP-Ab2 at a high HRP/Ab2 ratio. After a sandwich immunoreaction, the Fe3O4/Au-HRP-Ab2 captured on the electrode surface produced an amplified electrocatalytic response by reduction of enzymatically oxidized hydroquinone in the presence of hydrogen peroxide. The high content of HRP in the Fe3O4/Au-HRP-Ab2 could greatly amplify the electrochemical signal. Under optimal conditions, the reduction current increased with increasing alfa-fetoprotein concentration in the sample, and exhibited a dynamic range of 0.005–10 ng/mL with a detection limit of 3 pg/mL.Conclusion: The amplified immunoassay developed in this work shows good precision, acceptable stability, and reproducibility, and can be used for detection of alfa-fetoprotein in real samples, so provides a potential alternative tool for detection of protein in the laboratory. Furthermore, this immunosensor could be regenerated by simply using an external magnetic field.Keywords: Fe3O4/Au nanoparticles, alfa-fetoprotein, sandwich immunoassay, electrochemical immunosensor

  9. 酞菁镍与Fe3O4纳米粒子的复合机理及复合粒子的结构模型%COMPLEX MECHANISM OF PHTHALOCYANINE NICKEL WITH Fe3O4 ANOPARTICLES AND THE STRUCTURE MODEL OF THE NANOPARTICLES COMPOSITE

    Institute of Scientific and Technical Information of China (English)

    黄俊; 姜德生; 官建国; 袁润章

    2001-01-01

    In this article, the complex process of phthalocyanine nickel with Fe3O4 nanoparticles has been analyzed, the complex mechanism and the structure model for NiPc-Fe3O4 nanoparticles composite have been studied. For the complexes mechanism of NiPc with Fe3O4 nanoparticles, first, there are complex between NiPc and all Fe3O4 nanoparticles. Then, Fe3O4 nanoparticles accumulate together to form the accumulators; NiPc have the function of cohering Fe3O4 nanoparticles. A considerable number of NiPc combine with Fe3O4 nanoparticles and on the surface of the accumulators to form NiPc-Fe3O4 nanoparticles composite. All the processes above take place spontaneously. Inside the NiPc-Fe3O4 nanoparticles complex, Fe3O4 nanoparticles accumulate together without order, on the surface of composite, NiPc form a molecular dispersion layer. The threshold of the molecular dispersion layer is 0.06 g/g(Fe3O4).%分析了酞菁镍(NiPc)与Fe3O4纳米粒子的复合过程,提出了其复合机理.研究并建立了NiPc-Fe3O4纳米复合粒子的结构模型.

  10. Fabrication of nanoporous nanocomposites entrapping Fe3O4 magnetic nanoparticles and oxidases for colorimetric biosensing.

    Science.gov (United States)

    Kim, Moon Il; Shim, Jongmin; Li, Taihua; Lee, Jinwoo; Park, Hyun Gyu

    2011-09-12

    A nanostructured multicatalyst system consisting of Fe(3)O(4) magnetic nanoparticles (MNPs) as peroxidase mimetics and an oxidative enzyme entrapped in large-pore-sized mesoporous silica has been developed for convenient colorimetric detection of biologically important target molecules. The construction of the nanocomposites begins with the incorporation of MNPs on the walls of mesocellular silica pores by impregnating Fe(NO(3))(3)·9H(2)O, followed by the immobilization of oxidative enzymes. Glutaraldehyde crosslinking was employed to prevent enzymes leaching from the pores and led to over 20 wt% loading of the enzyme. The oxidase in the nanocomposite generates H(2)O(2) through its catalytic action for target molecules and subsequently activates MNPs to convert selected substrates into colored products. Using this strategy, two different biosensing systems were constructed employing glucose oxidase and cholesterol oxidase and their analytical capabilities were successfully verified by colorimetrically detecting the corresponding target molecules with excellent selectivity, sensitivity, reusability, and stability. Future potential applications of this technology range from biosensors to multicatalyst reactors. PMID:21837719

  11. Passively Q-switched EDFL using Fe3O4-nanoparticle saturable absorber

    CERN Document Server

    Bai, Xuekun; Xu, Luxi; Huang, Sujuan; Wang, Tingyun; Pu, Shengli; Zeng, Xianglong

    2015-01-01

    We experimentally demonstrate a passively Q-switched erbium-doped fiber laser (EDFL) operation by using a saturable absorber based on Fe3O4 nanoparticles (FONP) in magnetic fluid (MF). As a kind of transition metal oxide, the FONP has a large nonlinear optical response with a fast response time for saturable absorber. By depositing MF at the end of optical fiber ferrule, we fabricated a FONP-based saturable absorber, which enables a strong light-matter interaction owing to the confined transmitted optical field within the single mode fiber. Because of large third-order optical nonlinearities of FONP-based saturable absorber, large modulation depth of 8.2% and non saturable absorption of 56.6% are demonstrated. As a result, stable passively Q-switched EDFL pulses with maximum output pulse energy of 23.76 nJ, repetition rate of 33.3 kHz, and pulse width of 3.2 {\\mu}s are achieved when the input pump power is 110 mW at the wavelength of 980 nm. The laser features a low threshold pump power of ~15 mW.

  12. Multifunctional glucose biosensors from Fe3O4 nanoparticles modified chitosan/graphene nanocomposites

    Science.gov (United States)

    Zhang, Wenjing; Li, Xiaojian; Zou, Ruitao; Wu, Huizi; Shi, Haiyan; Yu, Shanshan; Liu, Yong

    2015-06-01

    Novel water-dispersible and biocompatible chitosan-functionalized graphene (CG) has been prepared by a one-step ball milling of carboxylic chitosan and graphite. Presence of nitrogen (from chitosan) at the surface of graphene enables the CG to be an outstanding catalyst for the electrochemical biosensors. The resulting CG shows lower ID/IG ratio in the Raman spectrum than other nitrogen-containing graphene prepared using different techniques. Magnetic Fe3O4 nanoparticles (MNP) are further introduced into the as-synthesized CG for multifunctional applications beyond biosensors such as magnetic resonance imaging (MRI). Carboxyl groups from CG is used to directly immobilize glucose oxidase (GOx) via covalent linkage while incorporation of MNP further facilitated enzyme loading and other unique properties. The resulting biosensor exhibits a good glucose detection response with a detection limit of 16 μM, a sensitivity of 5.658 mA/cm2/M, and a linear detection range up to 26 mM glucose. Formation of the multifunctional MNP/CG nanocomposites provides additional advantages for applications in more clinical areas such as in vivo biosensors and MRI agents.

  13. Sulphamic acid-functionalized magnetic Fe3O4 nanoparticles as recyclable catalyst for synthesis of imidazoles under microwave irradiation

    Indian Academy of Sciences (India)

    Javad Safari; Zohre Zarnegar

    2013-07-01

    Trisubstituted imidazoles have been synthesized in high yield in the presence of sulphamic acidfunctionalized magnetic Fe3O4 nanoparticles (SA-MNPs) as a novel solid acid catalyst under solvent-free classical heating conditions or using microwave irradiation. The heterogeneous catalyst could be recovered easily and reused many times without significant loss of catalytic activity.

  14. 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.

  15. Synthesis and characterization of Fe3O4@SiO2 magnetic composite nanoparticles by a one-pot process

    Science.gov (United States)

    Zhang, Le; Shao, Hui-ping; Zheng, Hang; Lin, Tao; Guo, Zhi-meng

    2016-09-01

    Fe3O4@SiO2 core-shell composite nanoparticles were successfully prepared by a one-pot process. Tetraethyl-orthosilicate was used as a surfactant to synthesize Fe3O4@SiO2 core-shell structures from prepared Fe3O4 nanoparticles. The properties of the Fe3O4 and Fe3O4@SiO2 composite nanoparticles were studied by X-ray diffraction, transmission electron microscopy, energy dispersive spectroscopy, and Fourier transform infrared spectroscopy. The prepared Fe3O4 particles were approximately 12 nm in size, and the thickness of the SiO2 coating was approximately 4 nm. The magnetic properties were studied by vibrating sample magnetometry. The results show that the maximum saturation magnetization of the Fe3O4@SiO2 powder (34.85 A·m2·kg-1) was markedly lower than that of the Fe3O4 powder (79.55 A·m2·kg-1), which demonstrates that Fe3O4 was successfully wrapped by SiO2. The Fe3O4@SiO2 composite nanoparticles have broad prospects in biomedical applications; thus, our next study will apply them in magnetic resonance imaging.

  16. Synthesis and characterization of Fe3O4/AuNPs magnetic composite nanoparticles%Fe3O4/AuNPs磁性复合粒子的制备与表征

    Institute of Scientific and Technical Information of China (English)

    代昭; 杨坤; 黄丹丹; 初园园

    2015-01-01

    通过溶剂热法合成了较大粒径的磁性Fe3O4纳米粒子,使用3-氨丙基三乙氧基硅烷(APTES)在乙醇/异丙醇体系中将其表面功能化一层氨基,随后将金纳米粒子(AuNPs)自组装于Fe3O4粒子表面,得到了Fe3O4/AuNPs纳米粒子;采用透射电子显微镜(TEM)、X-射线衍射(XRD)、振动样品磁强计(VSM)和紫外-可见光吸收光谱仪(UV-Vis)对复合粒子的形态、结构及性质进行表征。结果表明:所制备的Fe3O4磁纳米粒子粒径均一,平均粒径约为250 nm,形状几乎都呈球形,磁性Fe3O4/AuNPs复合粒子包覆均匀、具有良好的的分散性和磁化率,同时兼有磁性和金纳米粒子的特性。%Fe3O4 magnetic nanoparticles with large particle size were synthesized by a solvothermal method, and then modified by (3-aminopropyl)triethoxysilane (APTES) in the system of ethanol and isopropanol, which can functionalized the surface a layer of amino groups. Then, magnetic Fe3O4/Au nanoparticles were prepared by connecting gold nanoparticles under the condition of ultrasound. These composite particles have been characterized by transmission electron microscopy (TEM), X-ray powder diffraction (XRD), vibrating sample magnetometer(VSM) and ultraviolet-visible spectrophotometer (UV-Vis). The result shows that the prepared Fe3O4 nanoparticles have a uniform particle size and spherical shape, the average size is 250 nm. Fe3O4/Au composite particles coated evenly, have a good dispersibility and magnetic susceptibility, possess magnetism and characteristics of gold nanoparticles at the same time.

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

    Science.gov (United States)

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

    2012-11-01

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

  18. Novel magnetic Fe3O4-C nanoparticles as adsorbents for removal of organic dyes from aqueous solution

    International Nuclear Information System (INIS)

    Highlights: → In this work, novel magnetic Fe3O4-C nanoparticles have been synthesized and employed as high efficient adsorbent for removal cationic dyes from polluted water. → While up to now, little study is done on adsorption of dyes by the Fe3O4-C nanoparticles. → Hence, here we provide a simply and environment friendly method for removal of cationic dyes or other pollutants from water. - Abstract: The magnetic Fe3O4/C core-shell nanoparticles have been synthesized by a simple strategy and used as adsorbents for removal of organic dyes from aqueous solution. The resulting products are characterized by scanning electron microscope (SEM), energy dispersive X-ray spectrometry (EDX), X-ray photoelectron spectroscopy (XPS), X-ray diffraction (XRD), Raman spectra and Fourier transform infrared spectra (FTIR). Adsorption performances of the nanomaterial adsorbents are tested with removal of methylene blue (MB) and cresol red (CR) from aqueous solution. The effects of solution pH value, adsorption time and capacity of the nanocomposites have been fully investigated. The results reveal that the nanospheres can be easily manipulated by an external magnetic field with high separation efficiency. In addition, the process is clean and safe for purifying water pollution. The prepared Fe3O4/C complex nanomaterials could thus be used as promising adsorbents for the remove organic dyes, especially, cationic dye, from polluted water.

  19. Synthesis of Fe3O4/Pt Nanoparticles Decorated Carbon Nanotubes and Their Use as Magnetically Recyclable Catalysts

    Directory of Open Access Journals (Sweden)

    Hongkun He

    2011-01-01

    Full Text Available We report a facile approach to prepare Fe3O4/Pt nanoparticles decorated carbon nanotubes (CNTs. The superparamagnetic Fe3O4 nanoparticles with average size of 4∼5 nm were loaded on the surfaces of carboxyl groups functionalized CNTs via a high-temperature solution-phase hydrolysis method from the raw material of FeCl3. The synthesis process of magnetic CNTs is green and readily scalable. The loading amounts of Fe3O4 nanopartilces and the magnetizations of the resulting magnetic CNTs show good tunability. The Pt nanopaticles with average size of 2.5 nm were deposited on the magnetic CNTs through a solution-based method. It is demonstrated that the Fe3O4/Pt nanoparticles decorated CNTs have high catalytic activity in the reduction reaction of 4-nitrophenol and can be readily recycled by a magnet and reused in the next reactions with high efficiencies for at least fifteen successive cycles. The novel CNTs-supported magnetically recyclable catalysts are promising in heterogeneous catalysis applications.

  20. Synthesis of composite magnetic nanoparticles Fe3O4 with alendronate for osteoporosis treatment

    Directory of Open Access Journals (Sweden)

    Lee MS

    2016-09-01

    Full Text Available Ming-Song Lee,1,2 Chao-Ming Su,1 Jih-Chao Yeh,1,3 Pei-Ru Wu,4 Tien-Yao Tsai,1 Shyh-Liang Lou1,2 1Department of Biomedical Engineering, 2Department of Nanotechnology, Chung Yuan Christian University, Taoyuan, Taiwan; 3Institute of Urology, University of Southern California, Los Angeles, CA, USA; 4Department of Biomedical Sciences, College of Medicine, Chang Gung University, Taoyuan, Taiwan Abstract: Osteoporosis is a result of imbalance between bone formation by osteoblasts and resorption by osteoclasts (OCs. In the present study, we investigated the potential of limiting the aggravation of osteoporosis by reducing the activity of OCs through thermolysis. The proposed method is to synthesize bisphosphonate (Bis-conjugated iron (II, III oxide (Fe3O4 nanoparticles and incorporate them into OCs. The cells should be subsequently exposed to radiofrequency (RF to induce thermolysis. In this study, particles of Fe3O4 were first synthesized by chemical co-precipitation and then coated with dextran (Dex. The Dex/Fe3O4 particles were then conjugated with Bis to form Bis/Dex/Fe3O4. Transmission electron microscopy revealed that the average diameter of the Bis/Dex/Fe3O4 particles was ~20 nm. All three kinds of nanoparticles were found to have cubic inverse spinel structure of Fe3O4 by the X-ray diffraction analysis. Fourier transform infrared spectroscopy confirmed that the Dex/Fe3O4 and Bis/Dex/Fe3O4 nanoparticles possessed their respective Dex and Bis functional groups, while a superconducting quantum interference device magnetometer measured the magnetic moment to be 24.5 emu. In addition, the Bis/Dex/Fe3O4 nanoparticles were fully dispersed in double-distilled water. Osteoblasts and OCs were individually cultured with the nanoparticles, and an MTT assay revealed that they were non-cytotoxic. An RF system (42 kHz and 450 A was used to raise the temperature of the nanoparticles for 20 minutes, and the thermal effect was found to be sufficient

  1. Use of Fe3O4 Nanoparticles for Enhancement of Biosensor Response to the Herbicide 2,4-Dichlorophenoxyacetic Acid

    Directory of Open Access Journals (Sweden)

    Ishak Zamri

    2008-09-01

    Full Text Available Magnetic nanoparticles of Fe3O4 were synthesized and characterized using transmission electron microscopy and X-ray diffraction. The Fe3O4 nanoparticles were found to have an average diameter of 5.48 ±1.37 nm. An electrochemical biosensor based on immobilized alkaline phosphatase (ALP and Fe3O4 nanoparticles was studied. The amperometric biosensor was based on the reaction of ALP with the substrate ascorbic acid 2-phosphate (AA2P. The incorporation of the Fe3O4 nanoparticles together with ALP into a sol gel/chitosan biosensor membrane has led to the enhancement of the biosensor response, with an improved linear response range to the substrate AA2P (5-120 μM and increased sensitivity. Using the inhibition property of the ALP, the biosensor was applied to the determination of the herbicide 2,4-dichlorophenoxyacetic acid (2,4-D. The use of Fe3O4 nanoparticles gives a two-fold improvement in the sensitivity towards 2,4-D, with a linear response range of 0.5-30 μgL-1. Exposure of the biosensor to other toxicants such as heavy metals demonstrated only slight interference from metals such as Hg2+, Cu2+, Ag2+ and Pb2+. The biosensor was shown to be useful for the determination of the herbicide 2, 4-D because good recovery of 95-100 percent was obtained, even though the analysis was performed in water samples with a complex matrix. Furthermore, the results from the analysis of 2,4-D in water samples using the biosensor correlated well with a HPLC method.

  2. Fe3O4/PS magnetic nanoparticles: Synthesis, characterization and their application as sorbents of oil from waste water

    International Nuclear Information System (INIS)

    In this work, Fe3O4/PS composites with a rough surface and different coating rates were successfully designed and synthesized by emulsion polymerization. We carried out some comparative experiments to compare magnetic properties and oil absorption properties of the nano-magnetic materials. It had been found that several prepared groups of magnetic nanocomposites have a core–shell structure and good coating rates. These nanoparticles combined with unsinked, highly hydrophobic and superoleophilic properties. The absorption capacity of Fe3O4/PS composites for organic solvents and the composites could absorb diesel oil up to 2.492 times of its own weight. It is more important that the oil could be readily removed from the surfaces of nanoparticles by a simple ultrasonic treatment whereas the nanocomposites particles still kept highly hydrophobic and superoleophilic characteristics. With a combination of simple synthesis process, low density, magnetic responsibility and excellent hydrophobicity, Fe3O4/PS nanocomposites as a promising absorbent have great potential in the application of spilled oil recovery and environmental protection. - Graphical abstract: In this article, Fe3O4/PS nanoparticles present a property called selective adsorption. When the nanocomposites are added into watchglass with a layer diesel oil dyed by Sudan red for clarity on a water surface, oil is quickly absorbed in few seconds and then keeps a balance of adsorption. Owing to the presence of Fe3O4 nanoparticles, the nanocomposites could be collected to the oil-polluted region by a magnet bar. The particles can dissolve in ethanol by ultrasonic washing. After that we can regenerate the magnetic composite materials through filtering, washing and drying, the process is showed in the following Figure. Adsorption and desorption of Fe3O4/PS nanoparticles. - Highlights: • We prepared Fe3O4/PS nanocomposites with different coating rates by emulsion polymerization method successfully. • Prepared

  3. Preparation and characterization of biofunctionalized chitosan/Fe3O4 magnetic nanoparticles for application in liver magnetic resonance imaging

    Science.gov (United States)

    Song, Xiaoli; Luo, Xiadan; Zhang, Qingqing; Zhu, Aiping; Ji, Lijun; Yan, Caifeng

    2015-08-01

    Biofunctionalized chitosan@Fe3O4 nanoparticles are synthesized by combining Fe3O4 and CS chemically modified with PEG and lactobionic acid in one step. The biofunctionalized nanoparticles are characterized by TEM, X-ray, DLS, zeta-potential and magnetic measurements. The in vitro and in vivo behaviors of the biofunctionalized nanoparticles, especially, the cytotoxicity, the protein resistance, metabolism and iron toxicity are assessed. The functional groups, PEG enable the nanoparticles more biocompatible and the lactobionic acid groups enable liver targeting. The potential applications of the nanoparticles in liver magnetic resonance imaging are confirmed. The results demonstrated that the nanoparticles are suspension stability, non-cytotoxicity, non-tissue toxicity and sensitive in liver magnetic resonance imaging, representing potential tools for applications in the biomedical field.

  4. Magnetic iron oxide (Fe3O4) nanoparticles from tea waste for arsenic removal

    Science.gov (United States)

    Lunge, Sneha; Singh, Shripal; Sinha, Amalendu

    2014-04-01

    Magnetic iron oxide nanoparticles (MION-Tea) successfully synthesized using tea waste template. MION-Tea exhibit super magnetic properties under external magnetic field with saturation magnetization value of 6.9 emu/g at room temperature. SEM of MION-Tea shows cuboid/pyramid shaped crystals structure of Fe3O4 (magnetite). TEM of MION-Tea shows the particle size in the range of 5-25 nm. XRD pattern of MION-Tea is identical to magnetite. Magnetic nanoparticles are tested for removal of As(III) and As(V) from aqueous solution. The adsorption data obeyed the Langmuir equation with high adsorption capacity of 188.69 mg/g for arsenic (III), and 153.8 mg/g for arsenic (V). The mean sorption energy (E) calculated from D-R model, indicated physico-chemical sorption process. A pseudo-second-order kinetic model fitted best for As(III) adsorption on MION-Tea and the derived activation energy was 64.27 kJ/mol. Thermodynamics revealed the endothermic nature of adsorption. The effects of solution pH, interfering anions and initial As(III) concentration have been investigated. MION-Tea was very low cost (Rs. 136 per kg). MION-Tea can be reused up to 5 adsorption cycles and regenerated using NaOH. Cost of As(III) removal from water of was estimated to be Rs. 14 for 100 L. Comparison with reported adsorbents proved MION-Tea a potential adsorbent for As(III) and As(V) adsorption.

  5. Synthesis of magnetic core-shell structure Fe3O4@MCM-41 nanoparticle by vesicles in aqueous solutions☆

    Institute of Scientific and Technical Information of China (English)

    Weiming Song; Xuesong Liu; Ying Yang; Xuejia Han; Qigang Deng

    2015-01-01

    In this study, magnetic core–shel structure Fe3O4@MCM-41 nanoparticles were synthesized with vesicles as soft templates. In the preparation, FeCl2 and tetraethy orthosilicate (TEOS) were selected as Fe processor and Si pre-cursor, respectively. Stable vesicles first formed in 0.03 mol·L−1 1:2 mixture of anionic surfactant sodium dode-cyl sulfate and cationic surfactant cetyltrimethyl ammonium bromide. Then, TEOS was added in the vesicle aqueous solution, leading to a highly dispersed solution. After high-temperature calcination, Fe3O4@MCM-41 nanoparticles were obtained. Their structure and morphology were characterized by Saturn Digisizer, transmis-sion electron microscope and vibrating sample magneto-meter. The results indicate that the vesicles are spherical and their size could be tuned between 20 and 50 nm. The average grain diameter of synthesize magnetic core–shel Fe3O4@MCM-41 particles is 100–150 nm and most of them are in el iptical shape. The dispersion of magnet-ic particles is very good and magnetization values are up to 33.44 emu·g−1, which are superior to that of other Fe3O4 materials reported.

  6. Electrostatic Self-Assembly of Fe3O4 Nanoparticles on Graphene Oxides for High Capacity Lithium-Ion Battery Anodes

    Directory of Open Access Journals (Sweden)

    Jung Kyoo Lee

    2013-09-01

    Full Text Available Magnetite, Fe3O4, is a promising anode material for lithium ion batteries due to its high theoretical capacity (924 mA h g−1, high density, low cost and low toxicity. However, its application as high capacity anodes is still hampered by poor cycling performance. To stabilize the cycling performance of Fe3O4 nanoparticles, composites comprising Fe3O4 nanoparticles and graphene sheets (GS were fabricated. The Fe3O4/GS composite disks of mm dimensions were prepared by electrostatic self-assembly between negatively charged graphene oxide (GO sheets and positively charged Fe3O4-APTMS [Fe3O4 grafted with (3-aminopropyltrimethoxysilane (APTMS] in an acidic solution (pH = 2 followed by in situ chemical reduction. Thus prepared Fe3O4/GS composite showed an excellent rate capability as well as much enhanced cycling stability compared with Fe3O4 electrode. The superior electrochemical responses of Fe3O4/GS composite disks assure the advantages of: (1 electrostatic self-assembly between high storage-capacity materials with GO; and (2 incorporation of GS in the Fe3O4/GS composite for high capacity lithium-ion battery application.

  7. Influence of Monodisperse Fe3O4 Nanoparticle Size on Electrical Properties of Vegetable Oil-Based Nanofluids

    Directory of Open Access Journals (Sweden)

    Bin Du

    2015-01-01

    Full Text Available Insulating oil modified by nanoparticles (often called nanofluids has recently drawn considerable attention, especially concerning the improvement of electrical breakdown and thermal conductivity of the nanofluids. In this paper, three sized monodisperse Fe3O4 nanoparticles were prepared and subsequently dispersed into insulating vegetable oil to achieve nanofluids. The dispersion stability of nanoparticles in nanofluids was examined by natural sedimentation and zeta potential measurement. The electrical breakdown strength, space charge distribution, and several dielectric characteristics, for example, permittivity, dielectric loss, and volume resistivity of these nanofluids, were comparatively investigated. Experimental results show that the monodisperse Fe3O4 nanoparticles not only enhance the dielectric strength but also uniform the electric field of the nanofluids. The depth of electrical potential well of insulating vegetable oils and nanofluids were analyzed to clarify the influence of nanoparticles on electron trapping and on insulation improvement of the vegetable oil.

  8. Research on Magnetic Fe3O4 Nano-Particles Applied in Water Treatment%用于水处理的磁性Fe3O4纳米微粒研究

    Institute of Scientific and Technical Information of China (English)

    苏洁; 程文; 魏红; 何泽楠; 刘东; 左芬

    2012-01-01

    采用化学共沉淀法和水热法制备Fe3O4纳米磁性粒子及油酸包覆Fe3O4磁流体.通过实验确定最佳反应条件;用XRD分析Fe3O4粒子的晶体结构;用TEM观察磁流体样品的微观结构;用HPLC研究纳米粒子对左旋氧氟沙星溶液模拟废水超声降解的影响.结果表明产物为反尖晶石结构立方晶系的AB2O4型化合物,平均粒径小于15 nm;磁流体基本上为规则的球形,颗粒均匀,无团聚情况;制得的磁流体样品具有较好的流动性和超顺磁性;Fe3O4纳米粒子对左旋氧氟沙星具有一定的降解性能.%The Fe3O4 nano-particles and oil up on the Fe3O4 fluid are prepared by a chemical co-precipitation method and hydrothermal method. The optimum reaction conditions are determined through experiments. The crystal structure of Fe3O4 particles is analyzed via X-ray diffraction (XRD); the microstruc-ture of magnetic fluid sample is observed via transmission electron microscope (TEM); the effects of nano-particles on the degradation of levofloxacin solution imitating wastewater is investigated by high performance liquid chromatography( HPLC). The results show that the product is inverse spinel structure of the cubic crystal system-type compounds of AB204. The average particle size is less than 15 nm; magnetic fluid is regular spherical shape basically, particles uniformly and without agglomeration. Magnetic fluid samples are of good mobility and superparamagneticity; nano-size Fe3O4 can degrada levofloxacin to a certain extent.

  9. Preparation and characterization of poly(glycidyl methacrylate)-grafted magnetic nanoparticles: Effects of the precursor concentration on polyol synthesis of Fe3O4 and [PMDETA]0/[CuBr2]0 ratios on SI-AGET ATRP

    Science.gov (United States)

    Jiang, Liping; Zhou, Xuyang; Wei, Guyun; Lu, Xiaoduo; Wei, Weiping; Qiu, Jianhua

    2015-12-01

    Polymer brushes based on poly(glycidyl methacrylate) (PGMA) have been successfully grafted from the surface of silica coated iron oxide (Fe3O4@SiO2) nanoparticles via surface-initiated activators generated by electron transfer atom transfer radical polymerization (SI-AGET ATRP). The size of the nanoparticles could be adjusted from 7.3 to 9.6 nm by varying the precursor concentration of iron(III) acetylacetonate. The Fe3O4 nanoparticles possessed a highly crystalline structure, and the saturation magnetization of the as-prepared magnetite was strongly related to the particle size. Furthermore, the grafted PGMA content on the magnetic nanoparticles could be controlled by varying the ligand to transition metal ratio in a N,N,N‧,N″,N″-pentamethyldiethylenetriamine (PMDETA)/CuBr2 catalyst system. The maximum grafted content was 23.1% at a ratio of [PMDETA]0/[CuBr2]0 = 2:1.

  10. Effect of spatial confinement on magnetic hyperthermia via dipolar interactions in Fe3O4 nanoparticles for biomedical applications

    Energy Technology Data Exchange (ETDEWEB)

    Sadat, M E [University of Cincinnati; Patel, Ronak [University of Cincinnati; Sookoor, Jason [University of Cincinnati; Bud' ko, Sergey L [Ames Laboratory; Ewing, Rodney C [Stanford University; Zhang, Jiaming [Stanford University; Xu, Hong [Shanghai Jiao Tong University; Wang, Yilong [Tongji University School of Medicine; Pauletti, Giovanni M [University of Cincinnati; Mast, David B [University of Cincinnati; Shi, Donglu [University of Cincinnati

    2014-09-01

    In this work, the effect of nanoparticle confinement on the magnetic relaxation of iron oxide (Fe3O4) nanoparticles (NP) was investigated by measuring the hyperthermia heating behavior in high frequency alternating magnetic field. Three different Fe3O4 nanoparticle systems having distinct nanoparticle configurations were studied in terms of magnetic hyperthermia heating rate and DC magnetization. All magnetic nanoparticle (MNP) systems were constructed using equivalent ~10nm diameter NP that were structured differently in terms of configuration, physical confinement, and interparticle spacing. The spatial confinement was achieved by embedding the Fe3O4 nanoparticles in the matrices of the polystyrene spheres of 100 nm, while the unconfined was the free Fe3O4 nanoparticles well-dispersed in the liquid via PAA surface coating. Assuming the identical core MNPs in each system, the heating behavior was analyzed in terms of particle freedom (or confinement), interparticle spacing, and magnetic coupling (or dipole-dipole interaction). DC magnetization data were correlated to the heating behavior with different material properties. Analysis of DC magnetization measurements showed deviation from classical Langevin behavior near saturation due to dipole interaction modification of the MNPs resulting in a high magnetic anisotropy. It was found that the Specific Absorption Rate (SAR) of the unconfined nanoparticle systems were significantly higher than those of confined (the MNPs embedded in the polystyrene matrix). This increase of SAR was found to be attributable to high Néel relaxation rate and hysteresis loss of the unconfined MNPs. It was also found that the dipole-dipole interactions can significantly reduce the global magnetic response of the MNPs and thereby decrease the SAR of the nanoparticle systems.

  11. Mapping the subcellular localization of Fe3O4@TiO2 nanoparticles by X-ray Fluorescence Microscopy

    International Nuclear Information System (INIS)

    The targeted delivery of Fe3O4@TiO2 nanoparticles to cancer cells is an important step in their development as nanomedicines. We have synthesized nanoparticles that can bind the Epidermal Growth Factor Receptor, a cell surface protein that is overexpressed in many epithelial type cancers. In order to study the subcellular distribution of these nanoparticles, we have utilized the sub-micron resolution of X-ray Fluorescence Microscopy to map the location of Fe3O4@TiO2 NPs and other trace metal elements within HeLa cervical cancer cells. Here we demonstrate how the higher resolution of the newly installed Bionanoprobe at the Advanced Photon Source at Argonne National Laboratory can greatly improve our ability to distinguish intracellular nanoparticles and their spatial relationship with subcellular compartments

  12. Preparation and Characterization of Fe3O4 Magnetic Nano-particles by 60Co γ-ray Irradiation

    Institute of Scientific and Technical Information of China (English)

    Mingcheng YANG; Hongyan SONG; Chengshen ZHU; Suqin HE; Ya GAO

    2007-01-01

    By using a new method, 60C0 γ-ray irradiation, Fe3O4 magnetic nano-particles were successfully synthesized at room temperature under ambient pressure. The structure, morphology and magnetic properties of these nanoparticles were characterized by X-ray diffraction (XRD), transmission electron microscope (TEM) and vibrating sample magnetometer (VSM), respectively. The radiation formation mechanism was also discussed. The results show that the absorbed dose can greatly influence the structure, morphology and magnetic properties of the products. XRD and TEM studies show that the product prepared by γ-ray irradiation (10 kGy) is pure FesO4 phase and the mean diameter of these nano-particles is about 21 nm. The Fe3O4 nano-particles synthesized by γ-ray irradiation (10 kGy) are mainly in small cubic shape and the size uniformity of these particles is good.

  13. Biocompatible PEGylated Fe3O4 Nanoparticles as Photothermal Agents for Near-Infrared Light Modulated Cancer Therapy

    OpenAIRE

    Gang Yuan; Yongjie Yuan; Kan Xu; Qi Luo

    2014-01-01

    In accordance with the World Cancer Report, cancer has become the leading cause of mortality worldwide, and various therapeutic strategies have been developed at the same time. In the present study, biocompatible magnetic nanoparticles were designed and synthesized as high-performance photothermal agents for near-infrared light mediated cancer therapy in vitro. Via a facile one-pot solvothermal method, well-defined PEGylated magnetic nanoparticles (PEG–Fe3O4) were prepared with cheap inhesion...

  14. Effective decolorization and adsorption of contaminant from industrial dye effluents using spherical surfaced magnetic (Fe3O4) nanoparticles

    Science.gov (United States)

    Suriyaprabha, R.; Khan, Samreen Heena; Pathak, Bhawana; Fulekar, M. H.

    2016-04-01

    Treatment of highly concentrated Industrial dye stuff effluents released in the environment is the major issue faced in the era of waste management as well as in water pollution. Though there is availability of conventional techniques in large numbers, there is a need of efficient and effective advance technologies. In account of that, Nanotechnology plays a prominent role to treat the heavy metals, organic and inorganic contaminants using smart materials in nano regime (1 -100 nm). Among these nanomaterials like Iron Oxide (Fe3O4, magnetic nanoparticle) is one of the most promising candidates to remove the heavy metals from the industrial effluent. Fe3O4 is the widely used smart material with magnetic property having high surface area; high surface to volume ratio provides more surface for the chemical reaction for the surface adsorption. Fe3O4 nanoparticles have been synthesized using sonochemical method using ultra frequency in aqueous solution under optimized conditions. The as-synthesized nanoparticle was analyzed using different characterization tool. The Transmission Electron microscope (TEM) images revealed 10-12 nm spherical shape nanoparticles; crystal phase and surface morphology was confirmed by X-Ray Diffraction (XRD) and Scanning Electron Microscopy (SEM), respectively. The functional group were identified by Fourier Transform-Infra Red Spectroscopy (FT-IR), revealed the bending and stretching vibrations associated with Iron Oxide nanoparticle. In present study, for the efficient removal of contaminants, different concentration (10-50 ppm) of dye stuff effluent has been prepared and subjected to adsorption and decolourization at definite time intervals with Fe3O4 nanoparticles. The concentration of Iron oxide and the time (45 mins) was kept fixed for the reaction whereas the concentration of dye stuff effluent was kept varying. It was found that the spherical shaped Fe3O4 proved to be the potential material for the adsorption of corresponding

  15. Study on Preparation and Tribological Performance of Stearic Acid Capped Fe3O4 Nanoparticle%硬脂酸修饰纳米Fe3O4的制备及摩擦学性能的研究

    Institute of Scientific and Technical Information of China (English)

    杜润平; 柴多里

    2015-01-01

    通过微波水热法制备了表面修饰硬脂酸的纳米Fe3O4颗粒。运用红外光谱对其结构进行了分析,该添加剂具有较好的分散性与稳定性。经四球长磨实验表明,当表面修饰硬脂酸的纳米Fe3O4颗粒在液体石蜡油中的添加量为1.00%时,摩擦系数降至0.025,磨斑直径为0.47。%Stearic acid capped Fe3O4 nanoparticle was synthesized by using microwave hydrothermal method. The product was discussed on structure by IR. It has good dispersion and stability. A four-ball tribometer was employed to evaluate its tribological properties. The best tribological performance could be obtained with the coefficient of friction of 0.025,wear scar diameter of 0.47 mm,when the addition weight ratio of Stearic acid capped Fe3O4 nanoparticle in liquid paraffin is 1.00%.

  16. Modification of Fe3O4 Magnetic Nanoparticles by L-dopa or Dopamine as an Enzyme Support

    Institute of Scientific and Technical Information of China (English)

    PENG Hong; ZHANG Xiao; HUANG Kaixun; XU Huibi

    2008-01-01

    Fe3O4 magnetic nanoparticles were prepared by co-precipitation of Fe2+ and Fe3+ in an ammonia solution,and its size was about 36 am measured by an atomic force microscope.Fe3O4 magnetic nanopanicles were modified by L-dopa or dopamine using sonication method.The analysis of FTIR clearly indicated the formation of Fe-O-C bond.Direct immobilization of trypsin(EC:3.4.21.4)on Fe3O4 magnetic nanoparticles with L-dopa and dopamine spacer was investigated using glutaraldehyde as a coupling agent.No significant changes in the size and magnetic property of the three kinds of magnetic nanoparticles linked with or without trypsin were observed.The existence of the spacer molecule on magnetic nanoparticles could greatly improve the activity and the storage stability of bound trypsin through increasing the flexibility of enzyme and changing the microenvironment on nanoparticles surface compared to the naked magnetic nanoparticles.

  17. Effect of Fe3O4 nanoparticles on space charge distribution in propylene carbonate under impulse voltage

    International Nuclear Information System (INIS)

    Addition of nanoparticles of the ferromagnetic material Fe3O4 can increase the positive impulse breakdown voltage of propylene carbonate by 11.65%. To further investigate the effect of ferromagnetic nanoparticles on the space charge distribution in the discharge process, the present work set up a Kerr electro-optic field mapping measurement system using an array photodetector to carry out time-continuous measurement of the electric field and space charge distribution in propylene carbonate before and after modification. Test results show that fast electrons can be captured by Fe3O4 nanoparticles and converted into relatively slow, negatively charged particles, inhibiting the generation and transportation of the space charge, especially the negative space charge

  18. Synthesis and characterization of core-shell type Fe3O4 nanoparticles in poly(organosilsesquioxane).

    Science.gov (United States)

    Ervithayasuporn, Vuthichai; Kawakami, Yusuke

    2009-04-15

    The core-shell type Fe(3)O(4) nanoparticles in poly(organosilsesquioxane) (Fe(3)O(4)@OcTS) were prepared by one-pot synthesis using reverse micelle method. The as-prepared ferrofluid droplets with average size 4-15 nm were in situ encapsulated via polycondensation of molecularly self-assembled octenyltrimethoxysilane (OcTS). The dynamic light scattering and transmission electron microscopy investigations on coated magnetite nanoparticles revealed uniform size of spherical shape and having thin and transparent shells. These nanoparticles showed redispersibility in non-polar solvents without agglomerations due to coated by a layer of hydrophobic shells. The thermogravimetric analysis and infrared spectroscopy suggested the existence of core-shell type. X-ray diffraction confirmed magnetite cores. The superconducting quantum interference device (SQUID) showed that they exhibited superparamagnetic behavior at 300 K and ferromagnetic at 3 K. PMID:19150081

  19. Aqueous nickel-nitrilotriacetate modified Fe3O4-NH3+ nanoparticles for protein purification and cell targeting

    International Nuclear Information System (INIS)

    A comprehensive totally aqueous phase synthesis of nickel-nitrilotriacetate (Ni-NTA) modified superparamagnetic Fe3O4 nanoparticles is presented. The Fe3O4-NTA-Ni nanoparticles are able to perform efficient and specific purification of 6-His tagged proteins from crude cell lysates, as evidenced by sodium dodecyl sulphate polyacrylamide gel electrophoresis (SDS-PAGE) and Western blot analysis. The average binding capacity, as demonstrated by streptopain (MW 42 kDa), is 0.23 mg/mg (protein/Fe3O4-NTA-Ni). Considering the high affinity and specificity of the binding between hexahistidine motif and Ni-NTA, Ni-NTA modified nanoparticles could act as a module to carry 6-His tagged proteins on the particle surface with molecular orientation control, since only the 6-His domain could be attached. These modularly designed functional nanoparticles enhance cancer cell targeting, as supported by the in vitro receptor mediated targeting assay using RGD-4C-6-His fusion peptide. The nanoparticles show no significant hemolysis for human blood and could be investigated further for their in vivo functional imaging applications

  20. Formation and characterization of β-cyclodextrin (β-CD) - polyethyleneglycol (PEG) - polyethyleneimine (PEI) coated Fe3O4 nanoparticles for loading and releasing 5-Fluorouracil drug.

    Science.gov (United States)

    Prabha, G; Raj, V

    2016-05-01

    In this work, β-cyclodextrin (β-CD) - polyethyleneglycol (PEG) - polyethyleneimine (PEI) coated iron oxide nanoparticles (Fe3O4-β-CD-PEG-PEI) were developed as drug carriers for drug delivery applications. The 5- Fluorouracil (5-FU) was chosen as model drug molecule. The developed nanoparticles (Fe3O4-β-CD-PEG-PEI) were characterized by various techniques such as Fourier transform infrared (FTIR) spectroscopy, X-ray diffraction (XRD), Scanning electron microscopy (SEM), transmission electron microscopy (TEM) and vibrating sample magnetometry (VSM). The average particles size range of 5-FU loaded Fe3O4-β-CD, Fe3O4-β-CD-PEG and Fe3O4-β-CD-PEG-PEI nanoparticles were from 151 to 300nm and zeta potential value of nanoparticles were from -43mV to -20mV as measured using Malvern Zetasizer. Finally, encapsulation efficiency (EE), loading capacity (LC) and in-vitro drug release performance of 5-FU drug loaded Fe3O4-β-CD, Fe3O4-β-CD-PEG and Fe3O4-β-CD-PEG-PEI nanoparticles was evaluated by UV-vis spectroscopy. In-vitro cytotoxicity tests investigated by MTT assay indicate that 5-FU loaded Fe3O4-β-CD-PEG-PEI nanoparticles were toxic to cancer cells and non-toxic to normal cells. The in-vitro release behavior of 5-FU from drug (5-FU) loaded Fe3O4-β-CD-PEG-PEI composite at different pH values and temperature was studied. It was found that 5-FU was released faster in pH 6.8 than in the acidic mediums (pH 1.2), and the released quantity was higher. Therefore, the newly prepared Fe3O4-β-CD-PEG-PEI carrier exhibits a promising potential capability for anticancer drug delivery in tumor therapy.

  1. Preparation and evaluation of the effect of Fe3 O4 @piroctone olamine magnetic nanoparticles on matrix metalloproteinase-2: a preliminary in vitro study.

    Science.gov (United States)

    Shakibaie, Mojtaba; Haghiri, Mahboobe; Jafari, Mandana; Amirpour-Rostami, Sahar; Ameri, Alieh; Forootanfar, Hamid; Mehrabani, Mitra

    2014-01-01

    In the present study, Fe3 O4 magnetic nanoparticles were synthesized by the coprecipitation of Fe(2+) and Fe(3+) ions and used as a nanocarrier for the production of piroctone-olamine-loaded Fe3 O4 nanoparticles (Fe3 O4 @PO NPs). The nanocrystalline structure of the prepared iron oxide species was confirmed by the X-ray diffraction spectroscopy method. Particle size distribution analysis showed that the size of Fe3 O4 @PO NPs was in the range of 5-55 nm. The magnetization curve of Fe3 O4 @PO NPs (with saturation magnetization of 28.2 emu/g) confirmed its ferromagnetic property. Loading of PO on the surface of Fe3 O4 NPs qualitatively verified by Fourier transform infrared spectrum obtained from Fe3 O4 @PO NPs. Cytotoxicity studies on the human fibrosarcoma cell line (HT-1080) revealed higher inhibitory effect of Fe3 O4 @PO NPs (50% cell death [IC50 ] of 8.1 µg/mL) as compared with Fe3 O4 NPs (IC50 of 117.1 µg/mL) and PO (IC50 of 71.2 µg/mL) alone. In the case of human normal fibroblast (Hs68), the viability percentage was found to be 75% in the presence of Fe3 O4 @PO NPs (120 µg/mL). Gelatin zymography showed 17.2% and 34.6% inhibition of matrix metalloproteinase-2 (MMP-2) in the presence of Fe3 O4 @PO and PO, respectively, at the same concentration of 40 µg/mL, whereas Fe3 O4 NPs did not inhibit MMP-2 at any concentration. PMID:24716879

  2. Tailoring size and structural distortion of Fe3O4 nanoparticles for the purification of contaminated water.

    Science.gov (United States)

    Shen, Y F; Tang, J; Nie, Z H; Wang, Y D; Ren, Y; Zuo, L

    2009-09-01

    Fe(3)O(4) magnetic nanoparticles with different particle sizes were synthesized using two methods, i.e., a co-precipitation process and a polyol process, respectively. The atomic pair distribution analyses from the high-energy X-ray scattering data and TEM observations show that the two kinds of nanoparticles have different sizes and structural distortions. An average particle size of 6-8 nm with a narrow size distribution was observed for the nanoparticles prepared with the co-precipitation method. Magnetic measurements show that those particles are in ferromagnetic state with a saturation magnetization of 74.3 emu g(-1). For the particles synthesized with the polyol process, a mean diameter of 18-35 nm was observed with a saturation magnetization of 78.2 emu g(-1). Although both kinds of nanoparticles are well crystallized, an obviously higher structural distortion is evidenced for the co-precipitation processed nanoparticles. The synthesized Fe(3)O(4) particles with different mean particle size were used for treating the wastewater contaminated with the metal ions, such as Ni(II), Cu(II), Cd(II) and Cr(VI). It is found that the adsorption capacity of Fe(3)O(4) particles increased with decreasing the particle size or increasing the surface area. While the particle size was decreased to 8 nm, the Fe(3)O(4) particles can absorb almost all of the above-mentioned metal ions in the contaminated water with the adsorption capacity of 34.93 mg/g, which is approximately 7 times higher than that using the coarse particles. We attribute the extremely high adsorption capacity to the highly-distorted surface. PMID:19414249

  3. Breast Tumor Targetable Fe3O4 Embedded Thermo-Responsive Nanoparticles for Radiofrequency Assisted Drug Delivery.

    Science.gov (United States)

    Rejinold, N Sanoj; Thomas, Reju George; Muthiah, Muthunarayanan; Lee, Hwa Jeongong; Jeong, Yong Yeon; Park, In-kyu; Jayakumar, R

    2016-01-01

    Non-invasive radiofrequency (RF) frequency may be utilized as an energy source to activate thermo-responsive nanoparticles for the controlled local delivery of drugs to cancer cells. Herein, we demonstrate that 180 ± 20 nm sized curcumin encapsulated chitosan-graft-poly(N-vinyl caprolactam) nanoparticles containing iron oxide nanoparticles (Fe3O4-CRC-TRC-NPs) were selectively internalized in cancer cells in vivo. Using an RF treatment at 80 watts for 2 min, Fe3O4-CRC-TRC-NPs, dissipated heat energy of 42 degrees C, which is the lower critical solution temperature (LCST) of the chitosan-graft-poly(N-vinyl caprolactam), causing controlled curcumin release and apoptosis to cultured 4T1 breast cancer cells. Further, the tumor localization studies on orthotopic breast cancer model revealed that Fe3O4-CRC-TRC-NPs selectively accumulated at the primary tumor as confirmed by in vivo live imaging followed by ex vivo tissue imaging and HPLC studies. These initial results strongly support the development of RF assisted drug delivery from nanoparticles for improved tumor targeting for breast cancer treatment. PMID:27301171

  4. 叶酸偶联的Fe3O4纳米颗粒对活体肿瘤细胞的标记%Folate-conjugated Fe3O4 nanoparticles for in vivo tumor labeling

    Institute of Scientific and Technical Information of China (English)

    周春姣; 王少华; 周宇; 容鹏飞; 陈孜孜; 刘进言; 周建大

    2013-01-01

    Highly biocompatible superparamagnetic Fe3O4 nanoparticles were synthesized by amide of folic acid (FA) ligands and the NH2-group onto the surface of Fe3O4 nanoparticles. The as-synthesized folate-conjugated Fe3O4 nanoparticles were characterized by X-ray diffraction diffractometer, transmission electron microscope, FT-IR spectrometer, vibrating sample magnetometer, and dynamic light scattering instrument. The in vivo labeling effect of folate-conjugated Fe3O4 nanoparticles on the hepatoma cells was investigated in tumor-bearing rat. The results demonstrate that the as-prepared nanoparticles have cubic structure of Fe3O4 with a particle size of about 8 nm and hydrated diameter of 25.7 nm at a saturation magnetization of 51 A·m2/kg. These nanoparticles possess good physiological stability, low cytotoxicity on human skin fibroblasts and negligible effect on Wistar rats at the concentration as high as 3 mg/kg body mass. The folate-conjugated Fe3O4 nanoparticles could be effectively mediated into the human hepatoma Bel 7402 cells through the binding of folate and folic acid receptor, enhancing the signal contrast of tumor tissue and surrounding normal tissue in MRI imaging. It is in favor of the tumor cells labeling, tracing, magnetic resonance imaging (MRI) target detection and magnetic hyperthermia.%  采用酰胺化反应方法,通过Fe3O4纳米颗粒表面氨基基团和与肿瘤细胞具有高度亲和力的叶酸分子的羧基间反应进行偶联得到目标材料,利用X射线衍射、傅立叶红外光谱仪、透射电镜、振动样品磁强计、动态光散射仪等对所合成的材料进行表征,且以瘤鼠为动物模型,考察其活体肝癌细胞标记效果和MRI成像功能。结果表明,合成的材料为立方相的Fe3O4,粒径约8 nm,水合直径约25.7 nm,呈近似球形形貌,表面分布有羧基等功能基团,呈超顺磁特性,饱和磁化强度为51 A·m2/kg,能靶向进入肝癌细胞内,提高肿瘤与

  5. Adsorption of Pb2+ on amino-functionalized magnetic nanoparticles Fe3O4%氨基化磁纳米Fe3O4对铅离子的吸附研究

    Institute of Scientific and Technical Information of China (English)

    卢爱民; 张宇; 刘伟; 兰叶青; 蒋红梅

    2013-01-01

    采用水热法制备了一种氨基化磁纳米Fe3O4粒子,并采用X-射线衍射、透射电镜和红外光谱对该材料进行了表征.研究了氨基化磁纳米Fe3O4在不同pH、反应时间、添加量和初始金属离子浓度下对pb2+的吸附能力.结果表明:在pH 8.5、分析时间为10 min时对Pb2+的吸附率可达90%以上;随着氨基化磁纳米Fe3O4添加量的增加,其对pb2+的吸附能力也增强;随着Pb2+初始浓度的增加,氨基化磁纳米Fe3O4对pb2+的吸附率降低.氨基化磁纳米Fe3O4对Pb2+的吸附动力学和热力学分别符合准二级吸附模型和Langmuir等温吸附模型.不同浓度盐酸对保留在氨基化磁纳米Fe3O4上的pb2+的脱附影响研究结果显示:0.1 ~2.0 mol·L-1盐酸对氨基化磁纳米Fe3O4材料的脱附率均可达到85%以上,说明该材料具有循环利用的可能.%A novel amino-functionalized magnetic nanoparticle Fe3O4(NH2-MNPs) was prepared through hydro-thermal method and characterized by powder X-ray diffraction,Transmission electron microscopy and Infrared spectrometer. The effects of pH,reaction time, adsorbent dosage and the initial concentration of Pb2+ on the adsorption rate of Pb2+ were evaluated in this study. The results showed that the adsorption rate could be 90% when pH was 8. 5 and reaction time was 10 min. The adsorption rate of Pb2+ was found to have increased with the increasing of adsorbent dosage and decreased with the increasing of initial concentration of Pb2+. The dynamical and the equilibrium isotherm adsorption studies of Pb2* on amino-functionalized magnetic nanopartides Fe3 O4 followed pseudo-second-order rate mechanism and the Langmuir isotherm equation. Finally,the effect of different concentration of HC1 on the desorption ratio of Pb was also examined. And the results indicated that desorption rate could be obtained 85% during the evaluated HC1 concentration from 0. 1 to 2.0 mol·L-1 , which illustrated that it is possible to cyclicly

  6. Selective adsorption of Cr(VI) from aqueous solution by EDA-Fe3O4 nanoparticles prepared from steel pickling waste liquor

    International Nuclear Information System (INIS)

    Highlights: • Fe3O4 nanoparticles prepared from waste liquor were functionalized with EDA. • EDA-Fe3O4 nanoparticles had high adsorption capacity and selectivity for Cr(VI). • The adsorption kinetics, thermodynamics and isotherm were studied. • Electrostatic attraction and complexation were postulated as adsorption mechanisms. • EDA-Fe3O4 nanoparticles retained high capacity after several adsorption processes. - Abstract: In this study, Fe3O4 nanoparticles (NPs) prepared from steel pickling waste liquor were functionalized with ethylenediamine (EDA) to form EDA-Fe3O4 NPs for engineering applications. The obtained EDA-Fe3O4 NPs were characterized by transmission electron microscopy (TEM), scanning electron microscopy (SEM), X-ray diffraction (XRD), Brunauer–Emmett–Teller (BET) surface analyzer and Fourier-transform infrared (FTIR) spectroscopy. The results showed that the EDA-Fe3O4 NPs had a crystalline structure with a particle size range of 20–50 nm and a BET surface area of 28 m2 g−1. Functionalization with EDA was able to improve the adsorption selectivity of Fe3O4 for Cr(VI) in Cr(VI)/Cl−or Cr(VI)/SO42− double-mixture systems. The adsorption isotherm data fitted better to the Langmuir adsorption model, and the adsorption kinetics was better described by the pseudo-second order equation. The spontaneous and endothermic characteristics of this adsorption reaction were confirmed by thermodynamic study. Based on the results of X-ray photoelectron spectroscopy (XPS), electrostatic attraction and surface complexation between Cr(VI) and EDA-Fe3O4 NPs are postulated as mechanisms for the adsorption of Cr(VI) from aqueous solution. The EDA-Fe3O4 NPs retained a high adsorption capacity after several consecutive adsorption–desorption processes, indicating that EDA-Fe3O4 NPs serve as an excellent regenerable adsorbent for Cr(VI)

  7. Fabrication of Poly(γ-glutamic acid)-coated Fe3O4 Magnetic Nanoparticles and Their Application in Heavy Metal Removal

    Institute of Scientific and Technical Information of China (English)

    常菁; 仲兆祥; 徐虹; 姚忠; 陈日志

    2013-01-01

    In this study, poly(γ-glutamic acid)-coated Fe3O4 magnetic nanoparticles (γ-PGA/Fe3O4 MNPs) were successfully fabricated using the co-precipitation method. Fe3O4 MNPs were also prepared for comparison. The av-erage size and specific surface area results reveal thatγ-PGA/Fe3O4 MNPs (52.4 nm, 88.41 m2·g-1) have smaller particle size and larger specific surface area than Fe3O4 MNPs (62.0 nm, 76.83 m2·g-1). Theγ-PGA/Fe3O4 MNPs can remove over 99%of Cr3+, Cu2+and Pb2+, and over 77%of Ni2+in deionized water, much higher thanγ-PGA and Fe3O4 MNPs, attributed to the larger specific surface area ofγ-PGA/Fe3O4 MNPs. With the solution pH higher than 6.0,γ-PGA/Fe3O4 MNPs demonstrate better removal activity. The adsorption isotherm ofγ-PGA/Fe3O4 MNPs for Cr3+ fits the Freundlich model well, with the adsorption capacity of 24.60 mg·g-1. γ-PGA/Fe3O4 MNPs are strongly attracted by permanent magnet, so it is easy to separate them completely from water. With their high effi-ciency for heavy metal removal and easier separation,γ-PGA/Fe3O4 MNPs have great potential applications in wa-ter treatment.

  8. Activated carbon/Fe(3)O(4) nanoparticle composite: fabrication, methyl orange removal and regeneration by hydrogen peroxide.

    Science.gov (United States)

    Do, Manh Huy; Phan, Ngoc Hoa; Nguyen, Thi Dung; Pham, Thi Thu Suong; Nguyen, Van Khoa; Vu, Thi Thuy Trang; Nguyen, Thi Kim Phuong

    2011-11-01

    In the water treatment field, activated carbons (ACs) have wide applications in adsorptions. However, the applications are limited by difficulties encountered in separation and regeneration processes. Here, activated carbon/Fe(3)O(4) nanoparticle composites, which combine the adsorption features of powdered activated carbon (PAC) with the magnetic and excellent catalytic properties of Fe(3)O(4) nanoparticles, were fabricated by a modified impregnation method using HNO(3) as the carbon modifying agent. The obtained composites were characterized by X-ray diffraction, scanning and transmission electron microscopy, nitrogen adsorption isotherms and vibrating sample magnetometer. Their performance for methyl orange (MO) removal by adsorption was evaluated. The regeneration of the composite and PAC-HNO(3) (powdered activated carbon modified by HNO(3)) adsorbed MO by hydrogen peroxide was investigated. The composites had a high specific surface area and porosity and a superparamagnetic property that shows they can be manipulated by an external magnetic field. Adsorption experiments showed that the MO sorption process on the composites followed pseudo-second order kinetic model and the adsorption isotherm date could be simulated with both the Freundlich and Langmuir models. The regeneration indicated that the presence of the Fe(3)O(4) nanoparticles is important for a achieving high regeneration efficiency by hydrogen peroxide. PMID:21840037

  9. One-Pot Green Synthesis and Bioapplication ofl-Arginine-Capped Superparamagnetic Fe3O4 Nanoparticles

    Directory of Open Access Journals (Sweden)

    Lai Yongchao

    2009-01-01

    Full Text Available Abstract Water-solublel-arginine-capped Fe3O4 nanoparticles were synthesized using a one-pot and green method. Nontoxic, renewable and inexpensive reagents including FeCl3,l-arginine, glycerol and water were chosen as raw materials. Fe3O4 nanoparticles show different dispersive states in acidic and alkaline solutions for the two distinct forms of surface bindingl-arginine. Powder X-ray diffraction and X-ray photoelectron spectroscopy were used to identify the structure of Fe3O4 nanocrystals. The products behave like superparamagnetism at room temperature with saturation magnetization of 49.9 emu g−1 and negligible remanence or coercivity. In the presence of 1-ethyl-3-(dimethylaminopropyl carbodiimide hydrochloride, the anti-chloramphenicol monoclonal antibodies were connected to thel-arginine-capped magnetite nanoparticles. The as-prepared conjugates could be used in immunomagnetic assay. (See supplementary material 1 Electronic supplementary material The online version of this article (doi:10.1007/s11671-009-9480-x contains supplementary material, which is available to authorized users. Click here for file

  10. Preparation and imaging study of tumor-targeting MRI contrast agent based on Fe3O4 nanoparticles

    International Nuclear Information System (INIS)

    The detection and diagnosis of early hypoxic tumor is the key for successful cancer therapy, which remains a challenge for radiologists because contrast agents could hardly reach it. Herein, a tumor-targeting MRI contrast agent was prepared by conjugating the small-molecule inhibitor of carbonic anhydrase (CA IX) that is overexpressed in hypoxic tumor, mafenide, onto the surface of Fe3O4 magnetic nanoparticles (MNPs) to improve the sensitivity of MRI for early tumor diagnosis. The tumor-targeting MNP (Fe3O4-SO2NH2) showed enhanced MRI contrasting performance both in vitro and in vivo in comparison with the non-targeting control, which made it a promising contrast agent for the detection and diagnosis of early hypoxic tumor. (author)

  11. Fe3O4/PS magnetic nanoparticles: Synthesis, characterization and their application as sorbents of oil from waste water

    Science.gov (United States)

    Yu, Liuhua; Hao, Gazi; Gu, Junjun; Zhou, Shuai; Zhang, Ning; Jiang, Wei

    2015-11-01

    In this work, Fe3O4/PS composites with a rough surface and different coating rates were successfully designed and synthesized by emulsion polymerization. We carried out some comparative experiments to compare magnetic properties and oil absorption properties of the nano-magnetic materials. It had been found that several prepared groups of magnetic nanocomposites have a core-shell structure and good coating rates. These nanoparticles combined with unsinked, highly hydrophobic and superoleophilic properties. The absorption capacity of Fe3O4/PS composites for organic solvents and the composites could absorb diesel oil up to 2.492 times of its own weight. It is more important that the oil could be readily removed from the surfaces of nanoparticles by a simple ultrasonic treatment whereas the nanocomposites particles still kept highly hydrophobic and superoleophilic characteristics. With a combination of simple synthesis process, low density, magnetic responsibility and excellent hydrophobicity, Fe3O4/PS nanocomposites as a promising absorbent have great potential in the application of spilled oil recovery and environmental protection.

  12. Magnetic adsorbent of Fe3O4@SiO2 core-shell nanoparticles modified with thiol group for chloroauric ion adsorption

    Science.gov (United States)

    Roto, Roto; Yusran, Yusran; Kuncaka, Agus

    2016-07-01

    The magnetic adsorbent of Fe3O4@SiO2 core-shell nanoparticles modified with thiol group was synthesized for chloroauric ([AuCl4]-) adsorption. The Fe3O4 nanoparticles were prepared by co-precipitation method under mechanical stirring and coated with SiO2 by acid hydrolysis of Na2SiO3 under N2 purging. The coating of Fe3O4 nanoparticles with SiO2 prevents particles' agglomeration by forming Fe3O4 Fe3O4 Fe3O4@SiO2 core-shell and avoids dissolution of the Fe3O4 core in the acidic medium. The coated Fe3O4 particle was modified with a thiol group using 3-mercaptopropyltrimethoxysilane via silanization reaction. The results suggest that SiO2-coated Fe3O4 particles have a size of 10-20 nm. The FTIR and EDX data indicate that the thiol groups are successfully attached to the surface of the nanoparticles. The [AuCl4]- ion adsorption by the Fe3O4@SiO2 core-shell nanoparticles followed Langmuir isotherm model with a maximum adsorption capacity of 115 mg/g and free energy (ΔG°) of 24.8 kJ/mol. The thiourea solution can be used to desorb most of the adsorbed [AuCl4]- ion. The adsorption using magnetic compounds provides easy access to the separation for both preparation and recovery.

  13. Magnetic field induced ferroelectric and dielectric properties in Pb(Zr0.5Ti0.5)O3 films containing Fe3O4 nanoparticles

    International Nuclear Information System (INIS)

    About 1.05 μm-thick Pb(Zr0.5Ti0.5)O3 (PZT) films containing Fe3O4 nanoparticles were deposited on LaNiO3-coated silicon substrates through a sol-gel technique. Fe3O4 nanoparticles were effectively dispersed into PZT solution under the involvement of polyvinylpyrrolidone. X-ray diffraction confirmed the coexistence of PZT and Fe3O4 phases without other impurity phases. Scanning electron microscope revealed that the thick composite films possess well-defined and crack-free microstructure. The composite films exhibit good ferroelectric and ferromagnetic properties at room temperature. An obvious magnetodielectric effect has been demonstrated in the Pb(Zr0.5Ti0.5)O3/Fe3O4 composite films. Magnetic field induced change in ferroelectric polarization loop may support the possible magnetoelectric coupling between PZT and Fe3O4 phases.

  14. Preparation of the chitosan grafted poly (quaternary ammonium)/Fe3O4 nanoparticles and its adsorption performance for food yellow 3.

    Science.gov (United States)

    Yu, Chen; Geng, Jianqiang; Zhuang, Yunxia; Zhao, Jian; Chu, Liqiu; Luo, Xiaoxuan; Zhao, Ying; Guo, Yanwen

    2016-11-01

    Chitosan and its derivatives can be used to modify magnetic materials to promote the adsorption properties of the magnetic materials and avoid the weakness of chitosan and its derivatives. In the present study, chitosan grafted poly(trimethyl allyl ammonium chloride) (CTS-g-PTMAAC) was prepared by graft copolymerization; then it was coated on the surfaces of the sodium citrate coated Fe3O4 nanoparticles (SC-Fe3O4) to prepare a novel composite CTS-g-PTMAAC/SC-Fe3O4 magnetic nanoparticles, with which possesses abundant surface positive charges. The structure and properties of the CTS-g-PTMAAC/SC-Fe3O4 composite magnetic nanoparticles were characterized by FTIR, TEM, VSM, and zeta potential. The dye adsorption characteristics of the CTS-g-PTMAAC/SC-Fe3O4 nanoparticles were determined using the food yellow 3 aqueous solutions as a model food effluent. Effect of pH of the dye solution on the adsorption of food yellow 3 was determined and compared with N-2-hydroxylpropyl trimethyl ammonium chloride chitosan coated sodium citrate-Fe3O4 (CTS-g-HTCC/SC-Fe3O4) composite magnetic nanoparticles. The adsorption kinetics, adsorption isotherms, adsorption thermodynamics, and desorption and reusability of the magnetic nanoparticles were investigated. PMID:27516279

  15. Preparation of the chitosan grafted poly (quaternary ammonium)/Fe3O4 nanoparticles and its adsorption performance for food yellow 3.

    Science.gov (United States)

    Yu, Chen; Geng, Jianqiang; Zhuang, Yunxia; Zhao, Jian; Chu, Liqiu; Luo, Xiaoxuan; Zhao, Ying; Guo, Yanwen

    2016-11-01

    Chitosan and its derivatives can be used to modify magnetic materials to promote the adsorption properties of the magnetic materials and avoid the weakness of chitosan and its derivatives. In the present study, chitosan grafted poly(trimethyl allyl ammonium chloride) (CTS-g-PTMAAC) was prepared by graft copolymerization; then it was coated on the surfaces of the sodium citrate coated Fe3O4 nanoparticles (SC-Fe3O4) to prepare a novel composite CTS-g-PTMAAC/SC-Fe3O4 magnetic nanoparticles, with which possesses abundant surface positive charges. The structure and properties of the CTS-g-PTMAAC/SC-Fe3O4 composite magnetic nanoparticles were characterized by FTIR, TEM, VSM, and zeta potential. The dye adsorption characteristics of the CTS-g-PTMAAC/SC-Fe3O4 nanoparticles were determined using the food yellow 3 aqueous solutions as a model food effluent. Effect of pH of the dye solution on the adsorption of food yellow 3 was determined and compared with N-2-hydroxylpropyl trimethyl ammonium chloride chitosan coated sodium citrate-Fe3O4 (CTS-g-HTCC/SC-Fe3O4) composite magnetic nanoparticles. The adsorption kinetics, adsorption isotherms, adsorption thermodynamics, and desorption and reusability of the magnetic nanoparticles were investigated.

  16. Fe3O4磁性纳米微粒——一种新型多功能医学造影剂%Magnetic Fe3O4 nanoparticles--a new multi-functional contrast media

    Institute of Scientific and Technical Information of China (English)

    李文艳

    2011-01-01

    医学造影剂的发展使兼具疾病诊断与治疗等于一体的多功能造影剂的出现成为可能.Fe3O4磁性纳米微粒造影剂及其聚合物,因其特有的超顺磁性、靶向性、生物相容性及低细胞毒性而成为目前研究热点.本文就Fe3O4磁性纳米微粒造影剂的特性、制备及医学应用等方面进行一综述.%With the development of medical contrast media, the appearance of multi-functional contrast media for diagnosis and therapy has become possible. Magnetic Fej O4 nanoparticles and its synthesis attracted enormous research attention due to their unique magnetic properties, specific targeting, biocompatibility and low cytotoxicity. This article reviews the characteristics, preparation and medical applications of magnetic Fe3O4 nanoparticles.

  17. Synthesis and application of bilayer-surfactant-enveloped Fe3O4 nanoparticles: water-based bilayer-surfactant-enveloped ferrofluids

    Science.gov (United States)

    Chen, Bai-yi; Qiu, Jian-hui; Feng, Hui-xia

    2016-02-01

    Superparamagnetic carbon-coated Fe3O4 nanoparticles with high magnetization (85 emu·g-1) and high crystallinity were synthesized using polyethylene glycol-4000 (PEG (4000)) as a carbon source. Fe3O4 water-based bilayer-surfactant-enveloped ferrofluids were subsequently prepared using sodium oleate and PEG (4000) as dispersants. Analyses using X-ray photoelectron spectroscopy, X-ray diffraction, and Fourier-transform infrared spectroscopy indicate that the Fe3O4 nanoparticles with a bilayer surfactant coating retain the inverse spinel-type structure and are successfully coated with sodium oleate and PEG (4000). Transmission electron microscopy, vibrating sample magnetometry, and particle-size analysis results indicate that the coated Fe3O4 nanoparticles also retain the good saturation magnetization of Fe3O4 (79.6 emu·g-1) and that the particle size of the bilayer-surfactant-enveloped Fe3O4 nanoparticles is 42.97 nm, which is substantially smaller than that of the unmodified Fe3O4 nanoparticles (486.2 nm). UV-vis and zeta-potential analyses reveal that the ferrofluids does not agglomerate for 120 h at a concentration of 4 g·L-1, which indicates that the ferrofluids are highly stable.

  18. Size-dependent cytotoxicity of Fe3O4 nanoparticles induced by biphasic regulation of oxidative stress in different human hepatoma cells.

    Science.gov (United States)

    Xie, Yuexia; Liu, Dejun; Cai, Chenlei; Chen, Xiaojing; Zhou, Yan; Wu, Liangliang; Sun, Yongwei; Dai, Huili; Kong, Xianming; Liu, Peifeng

    2016-01-01

    The application of Fe3O4 nanoparticles (NPs) has made great progress in the diagnosis of disease and in the drug delivery system for cancer therapy, but the relative mechanisms of potential toxicity induced by Fe3O4 have not kept pace with its development in the application, which has hampered its further clinical application. In this article, we used two kinds of human hepatoma cell lines, SK-Hep-1 and Hep3B, to investigate the cytotoxic effects and the involved mechanisms of small Fe3O4 NPs with different diameters (6 nm, 9 nm, and 14 nm). Results showed that the size of NPs effectively influences the cytotoxicity of hepatoma cells: 6 nm Fe3O4 NPs exhibited negligible cytotoxicity and 9 nm Fe3O4 NPs affected cytotoxicity via cellular mitochondrial dysfunction and by inducing necrosis mediated through the mitochondria-dependent intracellular reactive oxygen species generation. Meanwhile, 14 nm Fe3O4 NPs induced cytotoxicity by impairing the integrity of plasma membrane and promoting massive lactate dehydrogenase leakage. These results explain the detailed mechanism of different diameters of small Fe3O4 NPs-induced cytotoxicity. We anticipate that this study will provide different insights into the cytotoxicity mechanism of Fe3O4 NPs, so as to make them safer to use in clinical application.

  19. Size-dependent cytotoxicity of Fe3O4 nanoparticles induced by biphasic regulation of oxidative stress in different human hepatoma cells

    Science.gov (United States)

    Xie, Yuexia; Liu, Dejun; Cai, Chenlei; Chen, Xiaojing; Zhou, Yan; Wu, Liangliang; Sun, Yongwei; Dai, Huili; Kong, Xianming; Liu, Peifeng

    2016-01-01

    The application of Fe3O4 nanoparticles (NPs) has made great progress in the diagnosis of disease and in the drug delivery system for cancer therapy, but the relative mechanisms of potential toxicity induced by Fe3O4 have not kept pace with its development in the application, which has hampered its further clinical application. In this article, we used two kinds of human hepatoma cell lines, SK-Hep-1 and Hep3B, to investigate the cytotoxic effects and the involved mechanisms of small Fe3O4 NPs with different diameters (6 nm, 9 nm, and 14 nm). Results showed that the size of NPs effectively influences the cytotoxicity of hepatoma cells: 6 nm Fe3O4 NPs exhibited negligible cytotoxicity and 9 nm Fe3O4 NPs affected cytotoxicity via cellular mitochondrial dysfunction and by inducing necrosis mediated through the mitochondria-dependent intracellular reactive oxygen species generation. Meanwhile, 14 nm Fe3O4 NPs induced cytotoxicity by impairing the integrity of plasma membrane and promoting massive lactate dehydrogenase leakage. These results explain the detailed mechanism of different diameters of small Fe3O4 NPs-induced cytotoxicity. We anticipate that this study will provide different insights into the cytotoxicity mechanism of Fe3O4 NPs, so as to make them safer to use in clinical application. PMID:27536098

  20. Tuning Fe3O4 nanoparticle dispersion through pH in PVA/guar gum/electrospun membranes.

    Science.gov (United States)

    Lubambo, A F; Ono, L; Drago, V; Mattoso, N; Varalda, J; Sierakowski, M-R; Sakakibara, C N; Freitas, R A; Saul, C K

    2015-12-10

    Polyvinyl Alcohol (PVA)/guar gum (GG) membranes with different loads of paramagnetic iron oxide Fe3O4 nanoparticles were successfully electrospun using both non-alkaline and alkaline stock solutions. The nanoparticle homogeneity distribution was clearly enhanced in fibers obtained from alkaline stock solutions. This is mainly due to the interaction between GG and the metallic ion, which also leads to further dispersion of remained uncoated nanoparticles in the mixture. It was also noticed that GG favors nanoparticle stability in the mixture and contributes to nanoparticle encapsulation. X-ray results showed that all membranes were semi-crystalline. FTIR-ATR spectra showed that Fe-O absorption band intensity improved with increasing nanoparticle load, reaching saturation at 3.5mg/ml Fe3O4 concentration under alkaline conditions. VSM analyses showed that the nanoparticles are paramagnetic and were successfully incorporated by the fibers. In vitro biocompatibility tests using L929 cells indicates adequate levels of cytotoxicity and cell adhesion/proliferation assays for both membranes obtained from non-alkaline and alkaline stock solutions. Therefore, they have potential for biomedical applications as biodegradable wound dressing. PMID:26428185

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

    Science.gov (United States)

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

    2013-07-23

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

  2. Bio-inspired green synthesis of Fe3O4 magnetic nanoparticles using watermelon rinds and their catalytic activity

    Science.gov (United States)

    Prasad, Ch.; Gangadhara, S.; Venkateswarlu, P.

    2016-08-01

    Novel and bio-inspired magnetic nanoparticles were synthesized using watermelon rinds (WR) which are nontoxic and biodegradable. Watermelon rind extract was used as a solvent and capping and reducing agent in the synthesis. The Fe3o4 MNPs were characterized by using transmission electron microscopy (TEM), X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR) and vibrating sample magnetometer techniques (VSM). XRD studies revealed a high degree of crystalline and monophasic Fe nanoparticles of face-centered cubic stricture. FTIR analysis proved that particles are reduced and stabilized in solution by the capping agent that is likely to be proteins secreted by the biomass. The present process in an excellent candidate for the synthesis of iron nanoparticles that is simple, easy to execute, pollutant free and inexpensive. A practical and convenient method for the synthesis of highly stable and small-sized iron nanoparticles with a narrow distribution from 2 to 20 nm is reported. Also, the MNPs present in higher saturation magnetization (Ms) of 14.2 emu/g demonstrate tremendous magnetic response behavior. However, the synthesized iron nanoparticles were used as a catalyst for the preparation of biologically interesting 2-oxo-1,2,3,4-tetrahydropyrimidine derivatives in high yields. These results exhibited that the synthesized Fe3O4 MNPs could be used as a catalyst in organic synthesis.

  3. Green Biosynthesis and Characterization of Magnetic Iron Oxide (Fe3O4 Nanoparticles Using Seaweed (Sargassum muticum Aqueous Extract

    Directory of Open Access Journals (Sweden)

    Rosfarizan Mohamad

    2013-05-01

    Full Text Available The synthesis of nanoparticles has become a matter of great interest in recent times due to their various advantageous properties and applications in a variety of fields. The exploitation of different plant materials for the biosynthesis of nanoparticles is considered a green technology because it does not involve any harmful chemicals. In this study, iron oxide nanoparticles (Fe3O4-NPs were synthesized using a rapid, single step and completely green biosynthetic method by reduction of ferric chloride solution with brown seaweed (BS, Sargassum muticum water extract containing sulphated polysaccharides as a main factor which acts as reducing agent and efficient stabilizer. The structural and properties of the Fe3O4-NPs were investigated by X-ray diffraction, Fourier transform infrared spectroscopy, field emission scanning electron microscopy (FESEM, energy dispersive X-ray fluorescence spectrometry (EDXRF, vibrating sample magnetometry (VSM and transmission electron microscopy. The average particle diameter as determined by TEM was found to be 18 ± 4 nm. X-ray diffraction showed that the nanoparticles are crystalline in nature, with a cubic shape. The nanoparticles synthesized through this biosynthesis method can potentially useful in various applications.

  4. Surfactant-enhanced spectrofluorimetric determination of total aflatoxins from wheat samples after magnetic solid-phase extraction using modified Fe3O4 nanoparticles

    Science.gov (United States)

    Manafi, Mohammad Hanif; Allahyari, Mehdi; Pourghazi, Kamyar; Amoli-Diva, Mitra; Taherimaslak, Zohreh

    2015-07-01

    The extraction and preconcentration of total aflatoxins (including aflatoxin B1, B2, G1, and G2) using magnetic nanoparticles based solid phase extraction (MSPE) followed by surfactant-enhanced spectrofluorimetric detection was proposed. Ethylene glycol bis-mercaptoacetate modified silica coated Fe3O4 nanoparticles as an efficient antibody-free adsorbent was successfully applied to extract aflatoxins from wheat samples. High surface area and strong magnetization properties of magnetic nanoparticles were utilized to achieve high enrichment factor (97), and satisfactory recoveries (92-105%) using only 100 mg of the adsorbent. Furthermore, the fast separation time (less than 10 min) avoids many time-consuming cartridge loading or column-passing procedures accompany with the conventional SPE. In determination step, signal enhancement was performed by formation of Triton X-100 micelles around the analytes in 15% (v/v) acetonitrile-water which dramatically increase the sensitivity of the method. Main factors affecting the extraction efficiency and signal enhancement of the analytes including pH of sample solution, desorption conditions, extraction time, sample volume, adsorbent amount, surfactant concentration and volume and time of micelle formation were evaluated and optimized. Under the optimum conditions, wide linear range of 0.1-50 ng mL-1 with low detection limit of 0.03 ng mL-1 were obtained. The developed method was successfully applied to the extraction and preconcentration of aflatoxins in three commercially available wheat samples and the results were compared with the official AOAC method.

  5. Anchoring Fe3O4 nanoparticles on three-dimensional carbon nanofibers toward flexible high-performance anodes for lithium-ion batteries

    Science.gov (United States)

    Wan, Yizao; Yang, Zhiwei; Xiong, Guangyao; Guo, Ruisong; Liu, Ze; Luo, Honglin

    2015-10-01

    There is growing interest in flexible, cost-effective, and binder-free energy storage devices to meet the special needs of modern electronic systems. Herein we report a general, scalable, eco-friendly, and cost-effective approach for the fabrication of nano-Fe3O4-anchored three-dimensional (3D) carbon nanofiber (CNFs) aerogels (Fe3O4@BC-CNFs). The preparation processes include the anchoring of Fe2O3 nanoparticles on bacterial cellulose (BC) nanofibers with intrinsic 3D network structure and subsequent carbonization at different temperatures. The aerogel carbonized at 600 °C (Fe3O4@BC-CNFs-600) is highly flexible and was directly used as working electrodes in lithium-ion batteries without metal current collectors, conducting additives, or binders. The Fe3O4@BC-CNFs-600 demonstrates greatly improved electrochemical performance in comparison to the bare Fe3O4 nanoparticles. In addition to its excellent flexibility, a stable capacity of 755 mAh g-1 for up to 80 cycles is also higher than most of carbon-Fe3O4 hybrids. The high reversible capacity and excellent rate capability are attributed to its 3D porous network structure with well-dispersed Fe3O4 nanoparticles on the surfaces of CNFs.

  6. Tailoring mechanical and antibacterial properties of chitosan/gelatin nanofiber membranes with Fe3O4 nanoparticles for potential wound dressing application

    Science.gov (United States)

    Cai, Ning; Li, Chao; Han, Chao; Luo, Xiaogang; Shen, Liang; Xue, Yanan; Yu, Faquan

    2016-04-01

    In this work, magnetic Fe3O4 nanoparticles (NPs) were utilized to improve the mechanical and antibacterial properties of chitosan (CS)/gelatin (GE) composite nanofiber membranes. Homogeneous Fe3O4/CS/GE nanofibers were electrospun successfully. Scanning electron microscopy (SEM) and transmission electron microscopy (TEM) images confirmed the presence of well-dispersed Fe3O4 NPs in the composite nanofibers. Fourier transform infrared spectroscopy (FTIR) spectra revealed the effective interactions of Fe3O4 NPs to the composite matrix through hydrogen bonding. The improvement on the thermal stability of the Fe3O4/CS/GE was observed by differential scanning calorimetry (DSC) and thermo gravimetric analysis (TGA), which is tightly correlated to strong filler-matrix adhesion. The incorporation of Fe3O4 NPs resulted in a substantial enhancement of mechanical properties. The optimum mechanical performance was demonstrated on 1 wt% Fe3O4/CS/GE nanofiber membranes, achieving 155% augment of Young's modulus, 128% increase of tensile strength, and 100% boost of toughness from CS/GE. The excellent mechanical enhancement can be explained by the effective dispersion of fillers and the filler-matrix interactions, which ensures the efficient load transfer from CS/GE matrix to Fe3O4 nanofillers. Moreover, zones of inhibition for Escherichia coli and Staphylococcus aureus expanded markedly with the supplement of Fe3O4 NPs. In all, nanofiber membranes made of Fe3O4/CS/GE composite with tailored mechanical and antibacterial properties appear a promising wound dressing material.

  7. Physical limits of pure superparamagnetic Fe3O4 nanoparticles for a local hyperthermia agent in nanomedicine

    Science.gov (United States)

    Jeun, Minhong; Lee, Sanghoon; Kyeong Kang, Jae; Tomitaka, Asahi; Wook Kang, Keon; Il Kim, Young; Takemura, Yasushi; Chung, Kyung-Won; Kwak, Jiyeon; Bae, Seongtae

    2012-02-01

    Magnetic and AC magnetically induced heating characteristics of Fe3O4 nanoparticles (IONs) with different mean diameters, d, systematically controlled from 4.2 to 22.5 nm were investigated to explore the physical relationship between magnetic phase and specific loss power (SLP) for hyperthermia agent applications. It was experimentally confirmed that the IONs had three magnetic phases and correspondingly different SLP characteristics depending on the particle sizes. Furthermore, it was demonstrated that pure superparamagnetic phase IONs (d limiting for hyperthermia applications due to smaller AC hysteresis loss power (Néel relaxation loss power) originated from lower out-of-phase magnetic susceptibility.

  8. Sol-gel synthesis of 8 nm magnetite (Fe 3O 4) nanoparticles and their magnetic properties

    KAUST Repository

    Lemine, O. M.

    2012-10-01

    Magnetite (Fe 3O 4) nanoparticles were successfully synthesized by a sol-gel method. The obtained nanoparticles were characterized by X-ray diffraction (XRD), field emission scanning electron microscopy (FE-SEM), energy dispersive analysis by X-ray (EDAX), transmission electron microscopy (TEM), superconducting quantum interference device (SQUID) and Mössbauer spectrometry. XRD and Mössbauer measurements indicate that the obtained nanoparticles are single phase. TEM analysis shows the presence of spherical nanoparticles with homogeneous size distribution of about 8 nm. Room temperature ferromagnetics behavior was confirmed by SQUID measurements. The mechanism of nanoparticles formation and the comparison with recent results are discussed. Finally, the synthesized nanoparticles present a potential candidate for hyperthermia application given their saturation magnetization. © 2012 Elsevier Ltd. All rights reserved.

  9. Recyclable enzyme mimic of cubic Fe3O4 nanoparticles loaded on graphene oxide-dispersed carbon nanotubes with enhanced peroxidase-like catalysis and electrocatalysis

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Hua; Li, Shuai; Si, Yanmei; Sun, Zhongzhao; Li, Shuying; Lin, Yuehe

    2014-01-01

    Fe3O4 nanoparticles as nanocatalysts may present peroxidase-like catalysis activities and high electrocatalysis if loaded on conductive carbon nanotube (CNT) supports; however, their catalysis performances in an aqueous system might still be challenged by the poor aqueous dispersion of hydrophobic carbon supports and/or low stability of loaded iron catalysts. In this work, amphiphilic graphene oxide nanosheets were employed as “surfactant” to disperse CNTs to create stable graphene oxide-dispersed CNT (GCNT) supports in water for covalently loading cubic Fe3O4 nanoparticles with improved distribution and binding efficiency. Compared with original Fe3O4 nanos and CNT-loaded Fe3O4 nanocomplex, the prepared GCNT–Fe3O4 nanocomposite could achieve higher aqueous stability and, especially, much stronger peroxidase-like catalysis and electrocatalysis to H2O2, presumably resulting from the synergetic effects of two conductive carbon supports and cubic Fe3O4 nanocatalysts effectively loaded. Colorimetric and direct electrochemical detections of H2O2 and glucose using the GCNT–Fe3O4 nanocomposite were conducted with high detection sensitivities, demonstrating the feasibility of practical sensing applications. Such a magnetically recyclable “enzyme mimic” may circumvent some disadvantages of natural protein enzymes and common inorganic catalysts, featuring the multi-functions of high peroxidase-like catalysis, strong electrocatalysis, magnetic separation/recyclability, environmental stability, and direct H2O2 electrochemistry.

  10. Influence of Fe3O4 Nanoparticles in Hydroxyapatite Scaffolds on Proliferation of Primary Human Fibroblast Cells

    Science.gov (United States)

    Maleki-Ghaleh, H.; Aghaie, E.; Nadernezhad, A.; Zargarzadeh, M.; Khakzad, A.; Shakeri, M. S.; Beygi Khosrowshahi, Y.; Siadati, M. H.

    2016-06-01

    Modern techniques for expanding stem cells play a substantial role in tissue engineering: the raw material that facilitates regeneration of damaged tissues and treats diseases. The environmental conditions and bioprocessing methods are the primary determinants of the rate of cultured stem cell proliferation. Bioceramic scaffolds made of calcium phosphate are effective substrates for optimal cell proliferation. The present study investigates the effects of two bioceramic scaffolds on proliferating cells in culture media. One scaffold was made of hydroxyapatite and the other was a mixture of hydroxyapatite and ferromagnetic material (Fe3O4 nanoparticles). Disk-shaped (10 mm × 2 mm) samples of the two scaffolds were prepared. Primary human fibroblast proliferation was 1.8- and 2.5-fold faster, respectively, when cultured in the presence of hydroxyapatite or ferrous nanoparticle/hydroxyapatite mixtures. Optical microscopy images revealed that the increased proliferation was due to enhanced cell-cell contact. The presence of magnetic Fe3O4 nanoparticles in the ceramic scaffolds significantly increased cell proliferation compared to hydroxyapatite scaffolds and tissue culture polystyrene.

  11. 磁性纳米Fe3O4的制备及性能表征%The Preparation and Function of Fe3O4 Nano-particles

    Institute of Scientific and Technical Information of China (English)

    周曾艳

    2006-01-01

    本文介绍纳米Fe3O4微粒和以纳米Fe3O4为核磁体的靶向药物的制备,对它们的性质进行XRD、IR、TEM、SEM、EDS表征,并对纳米Fe3O4微粒和以Fe3O4为载体的靶向药物进行了扩大化实验.

  12. Intensification of levofloxacin sono-degradation in a US/H2O2 system with Fe3O4 magnetic nanoparticles

    Institute of Scientific and Technical Information of China (English)

    Hong Wei; Da Hu; Jie Su; Kebin Li

    2015-01-01

    Fe3O4 magnetic nanoparticles (MNPs) were synthesised, characterised, and used as a peroxidase mimetic to ac-celerate levofloxacin sono-degradation in an ultrasound (US)/H2O2 system. The Fe3O4 MNPs were in nanometre scale with an average diameter of approximately 12 to 18 nm. The introduction of Fe3O4 MNPs increased levofloxacin sono-degradation in the US/H2O2 system. Experimental parameters, such as Fe3O4 MNP dose, initial solution pH, and H2O2 concentration, were investigated by a one-factor-at-a-time approach. The results showed that Fe3O4 MNPs enhanced levofloxacin removal in the pH range from 4.0 to 9.0. Levofloxacin removal ratio in-creased with Fe3O4 MNP dose up to 1.0 g·L−1 and with H2O2 concentration until reaching the maximum. More-over, three main intermediate compounds were identified by HPLC with electrospray ionisation tandem mass spectrometry, and a possible degradation pathway was proposed. This study suggests that combination of H2O2, Fe3O4 MNPs and US is a good way to improve the degradation efficiency of antibiotics.

  13. On the passivation mechanism of Fe3O4 nanoparticles during Cr(VI) removal from water: A XAFS study

    Science.gov (United States)

    Pinakidou, F.; Katsikini, M.; Simeonidis, K.; Kaprara, E.; Paloura, E. C.; Mitrakas, M.

    2016-01-01

    X-Ray Absorption Spectroscopies (XAFS) are employed in order to gather a thorough insight on the uptake mechanism of Cr(VI) by Fe3O4 nanoparticles under water treatment conditions. The XANES measurements identify that the reducing potential of Fe3O4 activates the precipitation of Cr(VI) in the form of insoluble and non-toxic Cr(III). However, electron donation from Fe(II) is responsible for its gradual consumption, resulting in the presence of a surface maghemite layer and the formation of structural vacancies. EXAFS analysis reveal that adsorption of Cr(III)-oxyanions occurs on sorption sites provided by the vacancies in the maghemite layer, where Cr(III) is involved in a bidentate binuclear (2E) geometry with Fe-octahedra while it also forms monodentate (1V) complexes with the Fe(III)O4 tetrahedra. The surface maghemitization along with the reduced Cr(III) adsorption into the vacancies, tracks the degree of Cr-reduction, since this surface structural modifications hinder Cr(VI) access to the Fe(II) ions of the magnetite nanoparticles. Thus, high surface coverage leads to the passivation of the reduction ability since physisorbed Cr(VI) is also detected through the formation of outer sphere complexes.

  14. Quantitative two-dimensional strain mapping of small core-shell FePt@Fe3O4 nanoparticles

    Science.gov (United States)

    Monteforte, Marianne; Kobayashi, Shoko; Tung, Le D.; Higashimine, Koichi; Mott, Derrick M.; Maenosono, Shinya; Thanh, Nguyen T. K.; Robinson, Ian K.

    2016-03-01

    We report a facile one-pot chemical synthesis of colloidal FePt@Fe3O4 core-shell nanoparticles (NPs) with an average diameter of 8.7 ± 0.4 nm and determine their compositional morphology, microstructure, two-dimensional strain, and magnetic hysteresis. Using various state-of-the-art analytical transmission electron microscopy (TEM) characterization techniques—including high resolution TEM imaging, TEM tomography, scanning TEM-high angle annular dark field imaging, and scanning TEM-energy dispersive x-ray spectroscopy elemental mapping—we gain a comprehensive understanding of the chemical and physical properties of FePt@Fe3O4 NPs. Additional analysis using x-ray photoelectron spectroscopy, x-ray diffraction, and superconducting quantum interference device magnetometry distinguishes the oxide phase and determines the magnetic properties. The geometric phase analysis method is effective in revealing interfacial strain at the core-shell interface. This is of fundamental interest for strain engineering of nanoparticles for desirable applications.

  15. Preparation and characterization of magnetic Fe3O 4/CNT nanoparticles by RPO method to enhance the efficient removal of Cr(VI).

    Science.gov (United States)

    Chen, Runhua; Chai, Liyuan; Li, Qinzhu; Shi, Yan; Wang, Yangyang; Mohammad, Ali

    2013-10-01

    This work described a novel method for the synthesis of high-ferromagnetism nanoparticles (Fe3O4/CNTs) to efficiently remove Cr(VI) from aqueous solution. The Fe3O4/carbon nanotubes (CNTs) were prepared by in situ reduction with post-oxidation method by using cheap and environmentally friendly precursor under mild condition. Magnetic hysteresis loops revealed that Fe3O4/CNTs had superior saturation magnetization (152 emu/g), enabling the highly efficient recovery of Fe3O4/CNTs from aqueous solution by magnetic separation at low magnetic field gradients. FTIR, Raman, XPS, and TEM observations were employed to characterize the physical-chemical properties of Fe3O4/CNTs, demonstrating that CNTs were successfully coated with iron oxide matrix. The adsorption equilibrium of Cr(VI) on Fe3O4/CNTs was reached within 30 min. Langmuir, Freundlich, and Dubinin-Radushkevich isotherm were chosen to analyze the equilibrium data. The results indicated that Langmuir model can well describe the equilibrium data with the maximum adsorption capacity of 47.98 mg/g at room temperature and 83.54 mg/g at 353 K. The adsorption capacity of Fe3O4/CNTs for Cr(VI) was greatly improved as compared to raw CNTs and other similar adsorbents reported. The pseudo-second-order kinetic model provided the best description of Cr(VI) adsorption on Fe3O4/CNTs. Most importantly, possible synthesis mechanism and Cr(VI) removal mechanism were explored. The results suggest that large amounts of Cr(VI) were adsorbed on Fe3O4/CNTs surface by substituting the surface position of -OH and then reducing it to Cr(OH)3 and Cr2O3. PMID:23644945

  16. Fe3 O4 nanoparticle redox system modulation via cell-cycle progression and gene expression in human mesenchymal stem cells.

    Science.gov (United States)

    Periasamy, Vaiyapuri S; Athinarayanan, Jegan; Alhazmi, Mohammad; Alatiah, Khalid A; Alshatwi, Ali A

    2016-08-01

    The use of engineered nanoparticles (NPs) across multiple fields and applications has rapidly increased over the last decade owing to their unusual properties. However, there is an increased need in understanding their toxicological effect on human health. Particularly, iron oxide (Fe3 O4 ) have been used in various sectors, including biomedical, food, and agriculture, but the current understanding of their impact on human health is inadequate. In this investigation, we assessed the toxic effect of Fe3 O4 NPs on human mesenchymal stem cells (hMSCs) adopting cell viability, cellular morphological changes, mitochondrial transmembrane potential, and cell-cycle progression assessment methodologies. Furthermore, the expression of oxidative stress, cell death, and cell-cycle regulatory genes was assessed using quantitative polymerase chain reaction. The Fe3 O4 NPs induced cytotoxicity and nuclear morphological changes in hMSCs by dose and time exposure. Cell-cycle analysis indicated that Fe3 O4 NPs altered the cell-cycle progression through a decrease in the proportion of cells in the G0 -G1 phase. The hMSC mitochondrial membrane potential loss increased with an increase in the concentration of Fe3 O4 NPs exposure. The observed expression levels of the CYP1A, TNF3, TNFSF10, E2F1, and CCNC genes were significantly upregulated in hMSCs in response to Fe3 O4 NPs exposure. Our findings suggest that Fe3 O4 NPs caused metabolic stress through altered cell cycle, oxidative stress, and cell death regulatory gene expression in hMSCs. The results of this investigation revealed that Fe3 O4 NPs exhibited moderate toxicity on hMSCs and that Fe3 O4 NPs may have biomedical applications at low concentrations. © 2014 Wiley Periodicals, Inc. Environ Toxicol 31: 901-912, 2016. PMID:25532727

  17. The synthesis and properties of bifunctional and intelligent Fe3O4@titanium oxide core/shell nanoparticles.

    Science.gov (United States)

    Yin, Yichao; Liu, Chenjie; Wang, Baoxiang; Yu, Shoushan; Chen, Kezheng

    2013-05-21

    A simple, one-pot solvothermal method has been demonstrated for the preparation of bifunctional Fe3O4@titanium oxide core/shell nanoparticles. In a typical procedure, tetraalkoxyl titanium Ti(OC4H9)4 and FeCl3 as precursors were added into ethylene glycol and further solvothermal treatment was used to synthesize the core/shell particles. The core/shell particles were characterized by scanning electron microscopy (SEM), transmission electron microscopy (TEM), X-ray diffraction (XRD), SQUID MPMS and rheometry. The morphological results showed titanium oxide nanorods with 100-200 nm length and 10-20 nm diameter coated on the surface of 200-300 nm Fe3O4 submicrospheres. Reaction time, the titanium source, the barium salt etc. have an influence on the morphology of core/shell particles. The core/shell particles can not only respond to an external magnetic field, but also to an electric field--a novel application of electrorheological fluid. PMID:23532087

  18. Covalent TiO(2)/pectin microspheres with Fe(3)O(4) nanoparticles for magnetic field-modulated drug delivery.

    Science.gov (United States)

    da Silva, Elisangela P; Sitta, Danielly L A; Fragal, Vanessa H; Cellet, Thelma S P; Mauricio, Marcos R; Garcia, Francielle P; Nakamura, Celso V; Guilherme, Marcos R; Rubira, Adley F; Kunita, Marcos H

    2014-06-01

    Covalent TiO(2)-co-pectin microspheres containing Fe(3)O(4) nanoparticles were developed through an ultrasound-induced crosslinking/polymerization reaction between the glycidyl methacrylate from vinyl groups in TiO(2) and in pectin. ζ-potentials became less negative in the nanostructured microspheres, caused by the presence of both inorganic particles in the negatively charged pectin. The nanostructured pectin microspheres showed an amoxicillin release rate slower than that of pure pectin microspheres. The proposed microspheres were found to be a sustained release system of amoxicillin in the acid medium. Furthermore, the antibiotic release may be modulated by exposition of the microspheres to a remote magnetic field. In practical terms, the nanostructured microspheres could deliver a larger proportion of their initial load to specific site of action. The cytotoxic concentrations for 50% of VERO cells (CC(50)), calculated as the concentration required to reduce cell viability by 50% after 72h of incubation, for pectin-only microspheres and nanostructured pectin microspheres were 217.7±6.5 and 121.5±4.9μgmL(-1), respectively. The obtained CC(50) values indicated acceptable cytotoxic levels for an incubation period of 72h, showing that the pectin microspheres have a great pharmacological potential for uses in biological environments, even after the introduction of both Fe(3)O(4) and TiO(2).

  19. Viscosity of low volume concentrations of magnetic Fe3O4 nanoparticles dispersed in ethylene glycol and water mixture

    Science.gov (United States)

    Syam Sundar, L.; Venkata Ramana, E.; Singh, M. K.; De Sousa, A. C. M.

    2012-12-01

    This Letter reveals an experimental investigation of rheological properties of Fe3O4 nanoparticles dispersed in 60:40%, 40:60% and 20:80% (by weight) ethylene glycol and water mixture. Magnetic nanoparticles were synthesized by chemical coprecipitation method. The experiments were carried out in the particle volume concentration range from 0.0% to 1.0% and temperature range from 0 °C to 50 °C. Viscosity of nanofluid increases with increase of volume concentration and decreases with increase of temperature. The results indicate that the 60:40% EG/W based nanofluid is 2.94 times more viscous compared to the other base fluids. Einstein model was under predicting the experimental viscosity for all the base fluids.

  20. Compact Ag@Fe3O4 Core-shell Nanoparticles by Means of Single-step Thermal Decomposition Reaction

    Science.gov (United States)

    Brollo, Maria Eugênia F.; López-Ruiz, Román; Muraca, Diego; Figueroa, Santiago J. A.; Pirota, Kleber R.; Knobel, Marcelo

    2014-10-01

    A temperature pause introduced in a simple single-step thermal decomposition of iron, with the presence of silver seeds formed in the same reaction mixture, gives rise to novel compact heterostructures: brick-like Ag@Fe3O4 core-shell nanoparticles. This novel method is relatively easy to implement, and could contribute to overcome the challenge of obtaining a multifunctional heteroparticle in which a noble metal is surrounded by magnetite. Structural analyses of the samples show 4 nm silver nanoparticles wrapped within compact cubic external structures of Fe oxide, with curious rectangular shape. The magnetic properties indicate a near superparamagnetic like behavior with a weak hysteresis at room temperature. The value of the anisotropy involved makes these particles candidates to potential applications in nanomedicine.

  1. Nanosized Fe3O4 an efficient PCR yield enhancer-Comparative study with Au, Ag nanoparticles.

    Science.gov (United States)

    Kambli, Priyanka; Kelkar-Mane, Varsha

    2016-05-01

    Nanomaterials-assisted PCR is a promising field of nanobiotechnology that amalgamates nanomaterials into the conventional PCR system to achieve better amplification of desired product. With literature documenting the variable effects of these nanomaterials on the PCR yield and amplification; it was thought worthwhile to compare the PCR enhancing efficiency of three transition metal nanoparticles in form of stable colloidal suspensions at varying concentrations.The nanoparticles(NPs) of silver, gold and magnetite were chemically synthesized by reducing their respective salts and characterized using UV-vis spectroscopy. Their morphology was assessed using nanoparticle tracking system and AFM. The effect of these nanofluids on amplification of 800 bp prokaryotic DNA template with 30% GC content was studied using conventional thermal cycler. The reaction kinetics for all the three nanofluids yielded a Gaussian curve of amplification with varying concentrations. The ammonium salt of oleic acid coated magnetite (Fe3O4) nanoparticles at a concentration of 0.72 × 10(-2)nM and average size of 33 nm demonstrated highest amplification efficiency of 190% as compared to the citrate stabilized AgNP-25 nm (45%) and AuNP-15.19 nm (134%) using a conventional PCR system. The major reasons that allow Fe3O4 NPs outperform the other 2 transition metal NP's seem to be attributed to its heat conduction property as well as effective adsorption of PCR components onto the ammonium salt of oleic acid coated magnetite nanofluids. The data from our study offers valuable information for the application of ferrofluids as economically, efficient and effective alternative for nanomaterial-assisted PCR yield enhancers.

  2. Nanosized Fe3O4 an efficient PCR yield enhancer-Comparative study with Au, Ag nanoparticles.

    Science.gov (United States)

    Kambli, Priyanka; Kelkar-Mane, Varsha

    2016-05-01

    Nanomaterials-assisted PCR is a promising field of nanobiotechnology that amalgamates nanomaterials into the conventional PCR system to achieve better amplification of desired product. With literature documenting the variable effects of these nanomaterials on the PCR yield and amplification; it was thought worthwhile to compare the PCR enhancing efficiency of three transition metal nanoparticles in form of stable colloidal suspensions at varying concentrations.The nanoparticles(NPs) of silver, gold and magnetite were chemically synthesized by reducing their respective salts and characterized using UV-vis spectroscopy. Their morphology was assessed using nanoparticle tracking system and AFM. The effect of these nanofluids on amplification of 800 bp prokaryotic DNA template with 30% GC content was studied using conventional thermal cycler. The reaction kinetics for all the three nanofluids yielded a Gaussian curve of amplification with varying concentrations. The ammonium salt of oleic acid coated magnetite (Fe3O4) nanoparticles at a concentration of 0.72 × 10(-2)nM and average size of 33 nm demonstrated highest amplification efficiency of 190% as compared to the citrate stabilized AgNP-25 nm (45%) and AuNP-15.19 nm (134%) using a conventional PCR system. The major reasons that allow Fe3O4 NPs outperform the other 2 transition metal NP's seem to be attributed to its heat conduction property as well as effective adsorption of PCR components onto the ammonium salt of oleic acid coated magnetite nanofluids. The data from our study offers valuable information for the application of ferrofluids as economically, efficient and effective alternative for nanomaterial-assisted PCR yield enhancers. PMID:26896662

  3. Preparation of Chitosan modified Iron Oxide Nanoparticles%壳聚糖/Fe3O4复合纳米颗粒的制备

    Institute of Scientific and Technical Information of China (English)

    石浩明; 张树彪; 陈会英; 赵轶男; 崔韶晖; 那立艳; 华瑞年

    2012-01-01

    以柠檬酸为改性剂,制备水基Fe3O4磁性纳米粒子,基于静电自组装作用,使壳聚糖分子在水溶液中包覆Fe3O4纳米晶粒,获得壳聚糖/Fe3O4复合纳米颗粒液溶胶。扫描电子显微镜(SEM)分析结果表明,复合纳米颗粒平均粒径为49.0nm,标准差为11.0nm。X射线衍射(XRD)和红外光谱(FT-IR)分析结果表明,复合纳米颗粒由壳聚糖分子和Fe3O4晶体粒子构成。%The magnetic fluid was prepared by modifying the surface of F% 04 nanoparticles with citric acid. These Fe3O4 nanoparticles encapsulated by chitosan molecules through electrostatic force could be readily dispersed in aqueous solution. It was found in the SEM image that the aver- age diameter of nanocomplex was 49.0 nm, standard deviation was 11.0 nmo The particles prepared from chitosan and Fe3O4 were characterized by XRD and FF- IR nanocomplex analysis.

  4. Green synthesis of iron oxide (Fe3O4) nanoparticles using two selected brown seaweeds:Characterization and application for lead bioremediation

    Institute of Scientific and Technical Information of China (English)

    EL-KASSAS Hala Y; ALY-ELDEEN Mohamed A; GHARIB Samiha M

    2016-01-01

    The exploitation of different plant materials for the biosynthesis of nanoparticles is considered a green technology because it does not involve any harmful chemicals. In this study, iron oxide nanoparticles (Fe3O4-NPs) were synthesized using a completely green biosynthetic method by reduction of ferric chloride solution using brown seaweed water extracts. The two seaweedsPadina pavonica (Linnaeus) Thivy andSargassum acinarium (Linnaeus) Setchell 1933 were used in this study. The algae extract was used as a reductant of FeCl3 resulting in the phytosynthesis of Fe3O4-NPs. The phytogenic Fe3O4-NPs were characterized by surface plasmon band observed close to 402 nm and 415 nm; the obtained Fe3O4-NPs are in the particle sizes ranged from 10 to 19.5 nm and 21.6 to 27.4 nm forP. pavonica andS. acinarium, respectively. The strong signals of iron were reported in their corresponding EDX spectra. FTIR analyses revealed that sulphated polysaccharides are the main biomolecules in the algae extracts that do dual function of reducing the FeCl3 and stabilizing the phytogenic Fe3O4-NPs. The biosynthesized Fe3O4-NPs were entrapped in calcium alginates beads and used in Pb adsorption experiments. The biosynthesized Fe3O4-NPs alginate beads viaP. pavonica (Linnaeus) Thivy had high capacity for bioremoval of Pb (91%) while that ofS. acinarium (Linnaeus) Setchell 1933 had a capacity of (78%) after 75 min. The values of the process parameters for the maximum Pb removal efficiency by Fe3O4-NPs alginate beads synthesizedvia P. pavonica (Linnaeus) Thivy were also estimated.

  5. Reversal of multidrug resistance by cisplatin-loaded magnetic Fe3O4 nanoparticles in A549/DDP lung cancer cells in vitro and in vivo

    Directory of Open Access Journals (Sweden)

    Li K

    2013-05-01

    Full Text Available Ke Li,1 Baoan Chen,1,2 Lin Xu,3 Jifeng Feng,3 Guohua Xia,1,2 Jian Cheng,1,2 Jun Wang,1,2 Feng Gao,1,2 Xuemei Wang,41Department of Hematology, Key Medical Disciplines of Jiangsu Province, Zhongda Hospital, Medical School, Southeast University, Nanjing, 2Faculty of Oncology, Medical School, Southeast University, Nanjing, 3Department of Thoracic Surgery, Jiangsu Province Cancer Hospital, Jiangsu Province, 4State Key Laboratory of Bioelectronics, Southeast University, Nanjing, People’s Republic of ChinaAbstract: The purpose of this study was to explore whether magnetic Fe3O4 nanoparticles (Fe3O4-MNP loaded with cisplatin (Fe3O4-MNP-DDP can reverse DDP resistance in lung cancer cells and to investigate mechanisms of multidrug resistance in vitro and in vivo. MTT assay showed that DDP inhibited both A549 cells and DDP-resistant A549 cells in a time-dependent and dose-dependent manner, and that this inhibition was enhanced by Fe3O4-MNP. An increased rate of apoptosis was detected in the Fe3O4-MNP-DDP group compared with a control group and the Fe3O4-MNP group by flow cytometry, and typical morphologic features of apoptosis were confirmed by confocal microscopy. Accumulation of intracellular DDP in the Fe3O4-MNP-DDP group was greater than that in the DDP group by inductively coupled plasma mass spectrometry. Further, lower levels of multidrug resistance-associated protein-1, lung resistance-related protein, Akt, and Bad, and higher levels of caspase-3 genes and proteins, were demonstrated by reverse transcriptase polymerase chain reaction and Western blotting in the presence of Fe3O4-MNP-DDP. We also demonstrated that Fe3O4-MNP enhanced the effect of DDP on tumor growth in BALB/c nude mice bearing DDP-resistant human A549 xenografts by decreasing localization of lung resistance-related protein and Ki-67 immunoreactivity in cells. There were no apparent signs of toxicity in the animals. Overall, these findings suggest potential clinical application of

  6. The effect of suspended Fe3O4 nanoparticle size on magneto-optical properties of ferrofluids

    Science.gov (United States)

    Brojabasi, Surajit; Muthukumaran, T.; Laskar, J. M.; Philip, John

    2015-02-01

    We investigate the effect of hydrodynamic particle size on the magnetic field induced light transmission and transmitted speckle pattern in water based ferrofluids containing functionalized Fe3O4 nanoparticles of size ranging from 15 to 46 nm. Three water-based magnetic nanofluids, containing Fe3O4 nanoparticles functionalized with poly-acrylic acid (PAA), tetra-methyl ammonium hydroxide (TMAOH) and phosphate, are used in the present study. In all three cases, the transmitted light intensity starts decreasing above a certain magnetic field (called first critical field) and becomes a minimum at another field (second critical field). These two critical fields signify the onset of linear aggregation process and zippering transitions between fully grown chains, respectively. Both these critical fields shift towards a lower magnetic field with increasing hydrodynamic diameter, due to stronger magnetic dipolar interactions. The first and the second critical fields showed a power law dependence on the hydrodynamic diameters. The dipolar resonances occurring at certain values of the scatterer size, leads to the field induced extinction of light. Both the onset of chaining and zippering transitions were clearly evident in the time dependent transmitted light intensity. Above the first critical field, the lobe part of the transmitted intensity and the lobe speckle contrast values increase with increasing external magnetic field due to reduced Brownian motion of the field induced aggregates. The speckle contrast was highest for nanoparticle with the largest hydrodynamic diameter, due to reduced Brownian motion. These results provide better insight into field dependent light control in magnetic colloids, which may find interesting applications in magneto-optical devices.

  7. Selective adsorption of Cr(VI) from aqueous solution by EDA-Fe3O4 nanoparticles prepared from steel pickling waste liquor

    Science.gov (United States)

    Fang, X. B.; Fang, Z. Q.; Tsang, P. K. E.; Cheng, W.; Yan, X. M.; Zheng, L. C.

    2014-09-01

    In this study, Fe3O4 nanoparticles (NPs) prepared from steel pickling waste liquor were functionalized with ethylenediamine (EDA) to form EDA-Fe3O4 NPs for engineering applications. The obtained EDA-Fe3O4 NPs were characterized by transmission electron microscopy (TEM), scanning electron microscopy (SEM), X-ray diffraction (XRD), Brunauer-Emmett-Teller (BET) surface analyzer and Fourier-transform infrared (FTIR) spectroscopy. The results showed that the EDA-Fe3O4 NPs had a crystalline structure with a particle size range of 20-50 nm and a BET surface area of 28 m2 g-1. Functionalization with EDA was able to improve the adsorption selectivity of Fe3O4 for Cr(VI) in Cr(VI)/Cl-or Cr(VI)/SO42- double-mixture systems. The adsorption isotherm data fitted better to the Langmuir adsorption model, and the adsorption kinetics was better described by the pseudo-second order equation. The spontaneous and endothermic characteristics of this adsorption reaction were confirmed by thermodynamic study. Based on the results of X-ray photoelectron spectroscopy (XPS), electrostatic attraction and surface complexation between Cr(VI) and EDA-Fe3O4 NPs are postulated as mechanisms for the adsorption of Cr(VI) from aqueous solution. The EDA-Fe3O4 NPs retained a high adsorption capacity after several consecutive adsorption-desorption processes, indicating that EDA-Fe3O4 NPs serve as an excellent regenerable adsorbent for Cr(VI).

  8. Partial slip effect in flow of magnetite-Fe3O4 nanoparticles between rotating stretchable disks

    Science.gov (United States)

    Hayat, Tasawar; Qayyum, Sumaira; Imtiaz, Maria; Alzahrani, Faris; Alsaedi, Ahmed

    2016-09-01

    This paper addresses the flow of magnetic nanofluid (ferrofluid) between two parallel rotating stretchable disks with different rotating and stretching velocities. Water based fluid comprising magnetite-Fe3O4 nanoparticles is addressed. Velocity slip and temperature jump at solid-fluid interface are also taken into account. Appropriate transformations reduce the nonlinear partial differential system to ordinary differential system. Convergent series solutions are obtained. Effects of various pertinent parameters on the velocity and temperature profiles are shown and evaluated. Computations for skin friction coefficient and Nusselt number are presented and examined for the influence of involved parameters. It is noted that tangential velocity of fluid decreases for larger velocity slip parameter. Fluid temperature also reduces for increasing value of thermal slip parameter. Surface drag force and heat transfer rate at lower disk are enhanced when magnetic field strength is increased.

  9. 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

  10. Preparation and in vitro evaluation of doxorubicin-loaded Fe3O4 magnetic nanoparticles modified with biocompatible copolymers

    Directory of Open Access Journals (Sweden)

    Akbarzadeh A

    2012-02-01

    Full Text Available Abolfazl Akbarzadeh1, Haleh Mikaeili2, Nosratollah Zarghami3, Rahmati Mohammad3, Amin Barkhordari3, Soodabeh Davaran21Drug Applied Research Center, 2Tuberculosis and Lung Disease Research Center of Tabriz, 3Department of Clinical Biochemistry and Laboratory Medicine, Division of Medical Biotechnology, Faculty of Medicine, Tabriz University of Medical Sciences, Tabriz, IranBackground: Superparamagnetic iron oxide nanoparticles are attractive materials that have been widely used in medicine for drug delivery, diagnostic imaging, and therapeutic applications. In our study, superparamagnetic iron oxide nanoparticles and the anticancer drug, doxorubicin hydrochloride, were encapsulated into poly (D, L-lactic-co-glycolic acid poly (ethylene glycol (PLGA-PEG nanoparticles for local treatment. The magnetic properties conferred by superparamagnetic iron oxide nanoparticles could help to maintain the nanoparticles in the joint with an external magnet.Methods: A series of PLGA:PEG triblock copolymers were synthesized by ring-opening polymerization of D, L-lactide and glycolide with different molecular weights of polyethylene glycol (PEG2000, PEG3000, and PEG4000 as an initiator. The bulk properties of these copolymers were characterized using 1H nuclear magnetic resonance spectroscopy, gel permeation chromatography, Fourier transform infrared spectroscopy, and differential scanning calorimetry. In addition, the resulting particles were characterized by x-ray powder diffraction, scanning electron microscopy, and vibrating sample magnetometry.Results: The doxorubicin encapsulation amount was reduced for PLGA:PEG2000 and PLGA:PEG3000 triblock copolymers, but increased to a great extent for PLGA:PEG4000 triblock copolymer. This is due to the increased water uptake capacity of the blended triblock copolymer, which encapsulated more doxorubicin molecules into a swollen copolymer matrix. The drug encapsulation efficiency achieved for Fe3O4 magnetic nanoparticles

  11. The synthesis and characterization of monodispersed chitosan-coated Fe3O4 nanoparticles via a facile one-step solvothermal process for adsorption of bovine serum albumin.

    Science.gov (United States)

    Shen, Mao; Yu, Yujing; Fan, Guodong; Chen, Guang; Jin, Ying Min; Tang, Wenyuan; Jia, Wenping

    2014-01-01

    Preparation of magnetic nanoparticles coated with chitosan (CS-coated Fe3O4 NPs) in one step by the solvothermal method in the presence of different amounts of added chitosan is reported here. The magnetic property of the obtained magnetic composite nanoparticles was confirmed by X-ray diffraction (XRD) and magnetic measurements (VSM). Scanning electron microscopy (SEM) and transmission electron microscopy (TEM) allowed the identification of spherical nanoparticles with about 150 nm in average diameter. Characterization of the products by Fourier transform infrared spectroscopy (FTIR) demonstrated that CS-coated Fe3O4 NPs were obtained. Chitosan content in the obtained nanocomposites was estimated by thermogravimetric analysis (TGA). The adsorption properties of the CS-coated Fe3O4 NPs for bovine serum albumin (BSA) were investigated under different concentrations of BSA. Compared with naked Fe3O4 nanoparticles, the CS-coated Fe3O4 NPs showed a higher BSA adsorption capacity (96.5 mg/g) and a fast adsorption rate (45 min) in aqueous solutions. This work demonstrates that the prepared magnetic nanoparticles have promising applications in enzyme and protein immobilization. PMID:24994954

  12. Amperometric glucose sensor based on enhanced catalytic reduction of oxygen using glucose oxidase adsorbed onto core-shell Fe3O4-silica-Au magnetic nanoparticles

    International Nuclear Information System (INIS)

    Monodisperse Fe3O4 magnetic nanoparticles (NPs) were prepared under facile solvothermal conditions and successively functionalized with silica and Au to form core/shell Fe3O4-silica-Au NPs. Furthermore, the samples were used as matrix to construct a glucose sensor based on glucose oxidase (GOD). The immobilized GOD retained its bioactivity with high protein load of 3.92 × 10−9 mol·cm−2, and exhibited a surface-controlled quasi-reversible redox reaction, with a fast heterogeneous electron transfer rate of 7.98 ± 0.6 s−1. The glucose biosensor showed a broad linear range up to 3.97 mM with high sensitivity of 62.45 μA·mM−1 cm−2 and fast response (less than 5 s). - Graphical abstract: Core-shell structured Fe3O4-silica-Au nanoparticles were prepared and used as matrix to construct an amperometric glucose sensor based on glucose oxidase, which showed broad linear range, high sensitivity, and fast response. Highlights: ► Synthesis of monodispersed Fe3O4 nanoparticles. ► Fabrication of core/shell Fe3O4-silica-Au nanoparticles. ► Construction of a novel glucose sensor with wide linear range, high sensitivity and fast response.

  13. Paclitaxel conjugated Fe3O4@LaF3:Ce3+,Tb3+ nanoparticles as bifunctional targeting carriers for Cancer theranostics application

    Science.gov (United States)

    Mangaiyarkarasi, Rajendiran; Chinnathambi, Shanmugavel; Karthikeyan, Subramani; Aruna, Prakasarao; Ganesan, Singaravelu

    2016-02-01

    The bi-functional Chitosan functionalized magnetite doped luminescent rare earth nanoparticles (Fe3O4@LaF3: Ce3+,Tb3+/chi NPs) as a carrier of paclitaxel (PTX) drug was designed using a co-precipitation and facile direct precipitation method. The synthesized nanoparticles are spherical in shape with a typical diameter of 19-37 nm respectively. They are water soluble, super paramagnetic and biocompatible, in which the amino groups on the nanoparticles surface are used for the conjugation with an anticancer drug, paclitaxel. The nature of PTX binding with Fe3O4@LaF3: Ce3+,Tb3+/chi nanoparticles were studied using X-ray diffraction, vibrating sample magnetometer and scanning electron micrograph. The nature of interactions between PTX and Fe3O4@LaF3: Ce3+,Tb3+/chi NPs due to complex formation were conceded out by various spectroscopic methods viz., UV-visible, steady state and excited state fluorescence spectroscopy. The photo-physical characterization reveals that the adsorption and release of PTX from Fe3O4@LaF3:Tb3+/chi nanoparticles is quicker when compared with other nanoparticles and also confirms that this may be due to the hydrogen bond formation between the hydroxyl group of drug and amino group of nanoparticles respectively. The maximum loading capacity and entrapment efficiency of 83.69% and 80.51% were attained at a ratio of 5:8 of PTX and Fe3O4@LaF3: Ce3+,Tb3+/chi NPs respectively. In addition with that, antitumoral activity study of PTX conjugated Fe3O4@LaF3:Tb3+/chi nanoparticles exhibits increased cytotoxic effects on A549 lung cancer cell lines than that of unconjugated PTX.

  14. Passage of Magnetic Tat-Conjugated Fe3O4@SiO2 Nanoparticles Across In Vitro Blood-Brain Barrier

    Science.gov (United States)

    Zhao, Xueqin; Shang, Ting; Zhang, Xiaodan; Ye, Ting; Wang, Dajin; Rei, Lei

    2016-10-01

    Delivery of diagnostic or therapeutic agents across the blood-brain barrier (BBB) remains a major challenge of brain disease treatment. Magnetic nanoparticles are actively being developed as drug carriers due to magnetic targeting and subsequently reduced off-target effects. In this paper, we developed a magnetic SiO2@Fe3O4 nanoparticle-based carrier bound to cell-penetrating peptide Tat (SiO2@Fe3O4 -Tat) and studied its fates in accessing BBB. SiO2@Fe3O4-Tat nanoparticles (NPs) exhibited suitable magnetism and good biocompatibility. NPs adding to the apical chamber of in vitro BBB model were found in the U251 glioma cells co-cultured at the bottom of the Transwell, indicating that particles passed through the barrier and taken up by glioma cells. Moreover, the synergistic effects of Tat and magnetic field could promote the efficient cellular internalization and the permeability across the barrier. Besides, functionalization with Tat peptide allowed particles to locate into the nucleus of U251 cells than the non-conjugated NPs. These results suggest that SiO2@Fe3O4-Tat NPs could penetrate the BBB through the transcytosis of brain endothelial cells and magnetically mediated dragging. Therefore, SiO2@Fe3O4-Tat NPs could be exploited as a potential drug delivery system for chemotherapy and gene therapy of brain disease.

  15. Perspective of Fe3O4 Nanoparticles Role in Biomedical Applications

    Directory of Open Access Journals (Sweden)

    Mohammad Reza Ghazanfari

    2016-01-01

    Full Text Available In recent years, although many review articles have been presented about bioapplications of magnetic nanoparticles by some research groups with different expertise such as chemistry, biology, medicine, pharmacology, and materials science and engineering, the majority of these reviews are insufficiently comprehensive in all related topics like magnetic aspects of process. In the current review, it is attempted to carry out the inclusive surveys on importance of magnetic nanoparticles and especially magnetite ones and their required conditions for appropriate performance in bioapplications. The main attentions of this paper are focused on magnetic features which are less considered. Accordingly, the review contains essential magnetic properties and their measurement methods, synthesis techniques, surface modification processes, and applications of magnetic nanoparticles.

  16. Investigation of stabilization mechanism and size controlling of Fe3O4 nanoparticles using anionic chelating agents

    Science.gov (United States)

    Ghazanfari, Mohammad Reza; Kashefi, Mehrdad; Jaafari, Mahmoud Reza

    2016-07-01

    Chelating agents have potential effects on different properties of nanoparticles. Fe3O4 nanoparticles were synthesizes Using coprecipitation technique and oxalic, citric, stearic and lauric acids with concentrations of 0.5, 1, 2, and 5 vol% were utilized as the chelating agents. Subsequently, stability, structural, and magnetic properties of the samples were studied using measurement of zeta potential as well as FT-IR, XRD, DLS, TEM, and VSM analyses. It was found that the lower end of the size range was achieved for all samples utilizing 2 vol% chelating agents. So, in the present study, it was chosen as the optimum volume percentage of the chelating agents. Furthermore, for the nanoparticles treated with oxalic and citric acids, particle sizes were lower and the zeta potentials were larger comparing to those treated with stearic and lauric acids, which is an indication of their higher stabilization ability. Finally, the type of chelating agents had negligible effects on the structural and magnetic properties of the synthesized nanoparticles.

  17. Biopanning and characterization of peptides with Fe3O4 nanoparticles-binding capability via phage display random peptide library technique.

    Science.gov (United States)

    You, Fei; Yin, Guangfu; Pu, Ximing; Li, Yucan; Hu, Yang; Huang, Zhongbin; Liao, Xiaoming; Yao, Yadong; Chen, Xianchun

    2016-05-01

    Functionalization of inorganic nanoparticles (NPs) play an important role in biomedical applications. A proper functionalization of NPs can improve biocompatibility, avoid a loss of bioactivity, and further endow NPs with unique performances. Modification with vairous specific binding biomolecules from random biological libraries has been explored. In this work, two 7-mer peptides with sequences of HYIDFRW and TVNFKLY were selected from a phage display random peptide library by using ferromagnetic NPs as targets, and were verified to display strong binding affinity to Fe3O4 NPs. Fourier transform infrared spectrometry, fluorescence microscopy, thermal analysis and X-ray photoelectron spectroscopy confirmed the presence of peptides on the surface of Fe3O4 NPs. Sequence analyses revealed that the probable binding mechanism between the peptide and Fe3O4 NPs might be driven by Pearson hard acid-hard base specific interaction and hydrogen bonds, accompanied with hydrophilic interactions and non-specific electrostatic attractions. The cell viability assay indicated a good cytocompatibility of peptide-bound Fe3O4 NPs. Furthermore, TVNFKLY peptide and an ovarian tumor cell A2780 specific binding peptide (QQTNWSL) were conjugated to afford a liner 14-mer peptide (QQTNWSLTVNFKLY). The binding and targeting studies showed that 14-mer peptide was able to retain both the strong binding ability to Fe3O4 NPs and the specific binding ability to A2780 cells. The results suggested that the Fe3O4-binding peptides would be of great potential in the functionalization of Fe3O4 NPs for the tumor-targeted drug delivery and magnetic hyperthermia. PMID:26896661

  18. ARFI microbubble destruction improves targeted delivery of Fe3O4 nanoparticles to subcutaneous transplantation tumor in SD rats%ARFI破坏微泡增强Fe3O4纳米粒子在大鼠皮下移植瘤靶向递送的实验研究

    Institute of Scientific and Technical Information of China (English)

    刘思思; 丁俊; 李锐; 陈朝晖

    2015-01-01

    目的 制备一种具有磁共振显像功能的Fe3O4纳米粒子,通过声脉冲辐射成像(acoustic radiation force impulse,ARFI)辐照脂质微泡(microbubbles,MBs),探讨ARFI辐照微泡对Fe3O4纳米粒子在肿瘤组织分布的影响.方法 采用高温水热法制备Fe3O4纳米粒子,检测其形态、大小、分布等,观察其体外磁共振显像效果.选取60只SD雌性大鼠,体质量为170 ~200 g,制备Walker256皮下移植瘤模型,分为6组(n=10):单纯ARFI辐照组、单纯MBs组、ARFI辐照MBs组、单纯Fe3O4纳米粒子组、ARFI辐照Fe3O4纳米粒子组、ARFI辐照MBs和Fe3O4纳米粒子组.微泡0.2 mL及5 mg/kg Fe3O4纳米粒子经大鼠尾静脉推注,ARFI辐照条件为探头间隔5 s辐照肿瘤部位,累计辐照5 min.将处理后的SD大鼠肿瘤部位行MRI扫描观察肿瘤组织信号变化;处死SD大鼠,取组织标本行病理学分析.结果 制备的Fe3O4纳米粒子形态规则,粒径分布均匀,具有磁共振显像功能.SD大鼠肿瘤组织普鲁士蓝染色结果为单纯Fe3O4纳米粒子组、ARFI辐照Fe3O4纳米粒子组、ARFI辐照MBs和Fe3O4纳米粒子组均可见点状蓝染颗粒.其中ARFI辐照MBs和Fe3O4纳米粒子组蓝染颗粒计数明显多于其余2组(P<0.05).SD大鼠肿瘤部位磁共振成像结果为单纯Fe3O4纳米粒子组、ARFI辐照Fe3O4纳米粒子组、ARFI辐照MBs和Fe3O4纳米粒子组经相应处理后T2*WI均可见肿瘤内部低信号部分增加.结论 ARFI辐照MBs能够有效地提高Fe3O4纳米粒子在SD大鼠皮下移植瘤组织的分布,增强Fe3O4纳米粒子在活体肿瘤内的靶向递送效果.%Objective To prepare Fe3O4 nanoparticles and explore their in vitro magnetic resonance (MRI) effect,and investigate the impact of acoustic radiation force impulse (ARFI) microbubble (MB)destruction on targeted delivery of Fe3O4 nanoparticles to subcutaneous transplantation tumor in SD rats.Methods High-temperature hydrothermal reaction was used to prepare Fe3O4

  19. Synthesis and characterization of PVP-functionalized superparamagnetic Fe3O4 nanoparticles as an MRI contrast agent

    Directory of Open Access Journals (Sweden)

    2010-06-01

    Full Text Available The magnetite (Fe3O4 nanoparticles (MNPs coated with poly(N-vinyl pyrrolidone (PVP via covalent bonds were prepared as T2 contrast agent for magnetic resonance imaging (MRI. The surface of MNPs was first coated with 3-(trimethoxysilyl propyl methacrylate (silan A by a silanization reaction to introduce reactive vinyl groups onto the surface, then poly(N-vinyl pyrrolidone was grafted onto the surface of modified-MNPs via surface-initiated radical polymerization. The obtained nanoparticles were characterized by FT-IR (Fourier transform infrared spectroscopy, XRD (X-ray diffraction, TEM (transmission electron microscopy, VSM (vibrating sample magnetometer, and TGA (thermogravimetric analysis. The MNPs had an average size of 14 nm and exhibited superparamagnetism and high saturation magnetization at room temperature. T2-weighted MRI images of PVP-grafted MNPs showed that the magnetic resonance signal is enhanced significantly with increasing nanoparticle concentration in water. The r1 and r2 values per millimole Fe, and r2/r1 value of the PVP-grafted MNPs were calculated to be 2.6 , 72.1, and 28.1(mmol/l–1•s–1, respectively. These results indicate that the PVP-grafted MNPs have great potential for application in MRI as a T2 contrast agent.

  20. Preparation and Characterization of Fe3O4/CdTe Magnetic/Fluorescent Nanocomposites and their Applications in Immuno-labeling and Fluorescent Imaging of Cancer Cells

    OpenAIRE

    Sun, Pan; Zhang, Hongyan; Liu, Chang; Fang, Jin; WANG, Meng; Chen, Jing; Zhang, Jingpu; Mao, Chuanbin; Xu, Shukun

    2010-01-01

    The synthesis of a new kind of magnetic, fluorescent multifunctional nanoparticles (~30 nm in diameter) was demonstrated, where multiple fluorescent CdTe quantum dots (QDs) are covalently linked to and assembled around individual silica-coated superparamagnetic Fe3O4 nanoparticles and active carboxylic groups are presented on the surface for easy bioconjugation with biomolecules. The Fe3O4 nanoparticles were firstly functionalized with thiol groups, followed by chemical conjugation with multi...

  1. Enzyme-free fluorescent biosensor for the detection of DNA based on core-shell Fe3O4 polydopamine nanoparticles and hybridization chain reaction amplification.

    Science.gov (United States)

    Li, Na; Hao, Xia; Kang, Bei Hua; Xu, Zhen; Shi, Yan; Li, Nian Bing; Luo, Hong Qun

    2016-03-15

    A novel, highly sensitive assay for quantitative determination of DNA is developed based on hybridization chain reaction (HCR) amplification and the separation via core-shell Fe3O4 polydopamine nanoparticles (Fe3O4@PDA NPs). In this assay, two hairpin probes are designed, one of which is labeled with a 6-carboxyfluorescein (FAM). Without target DNA, auxiliary hairpin probes are stable in solution. However, when target DNA is present, the HCR between the two hairpins is triggered. The HCR products have sticky ends of 24 nt, which are much longer than the length of sticky ends of auxiliary hairpins (6 nt) and make the adsorption much easier by Fe3O4@PDA NPs. With the addition of Fe3O4@PDA NPs, HCR products could be adsorbed because of the strong interaction between their sticky ends and Fe3O4@PDA NPs. As a result, supernatant of the solution with target DNA emits weak fluorescence after separation by magnet, which is much lower than that of the blank solution. The detection limit of the proposed method is as low as 0.05 nM. And the sensing method exhibits high selectivity for the determination between perfectly complementary sequence and target with single base-pair mismatch. Importantly, the application of the sensor for DNA detection in human serum shows that the proposed method works well for biological samples.

  2. Controlling dynamic SERS hot spots on a monolayer film of Fe3O4@Au nanoparticles by a magnetic field

    Science.gov (United States)

    Guo, Qing-Hua; Zhang, Chen-Jie; Wei, Chao; Xu, Min-Min; Yuan, Ya-Xian; Gu, Ren-Ao; Yao, Jian-Lin

    2016-01-01

    A large surface-enhanced Raman scattering (SERS) effect is critically dependent on the gap distance of adjacent nanostructures, i.e., "hot spots". However, the fabrication of dynamically controllable hot spots still remains a remarkable challenge. In the present study, we employed an external magnetic field to dynamically control the interparticle spacing of a two-dimensional monolayer film of Fe3O4@Au nanoparticles at a hexane/water interface. SERS measurements were performed to monitor the expansion and shrinkage of the nanoparticles gaps, which produced an obvious effect on SERS activities. The balance between the electrostatic repulsive force, surface tension, and magnetic attractive force allowed observation of the magnetic-field-responsive SERS effect. Upon introduction of an external magnetic field, a very weak SERS signal appeared initially, indicating weak enhancement due to a monolayer film with large interparticle spacing. The SERS intensity reached maximum after 5 s and thereafter remained almost unchanged. The results indicated that the observed variations in SERS intensities were fully reversible after removal of the external magnetic field. The reduction of interparticle spacing in response to a magnetic field resulted in about one order of magnitude of SERS enhancement. The combined use of the monolayer film and external magnetic field could be developed as a strategy to construct hot spots both for practical application of SERS and theoretical simulation of enhancement mechanisms.

  3. Study of the enhanced anticancer efficacy of gambogic acid on Capan-1 pancreatic cancer cells when mediated via magnetic Fe3O4 nanoparticles

    Directory of Open Access Journals (Sweden)

    Wang C

    2011-09-01

    Full Text Available Cailian Wang1,*, Haijun Zhang1,*, Baoan Chen2, Haitao Yin1, Wenwen Wang11Department of Oncology, Zhongda Hospital, Medical School, Southeast University, Nanjing, People's Republic of China; 2Department of Hematology, Zhongda Hospital, Medical School, Southeast University, Nanjing, People's Republic of China *These authors contributed equally to this workBackground: Gambogic acid (GA, a potent anticancer agent, is limited in clinical administration due to its poor water solubility. The aim of this study was to explore a drug delivery system based on magnetic Fe3O4 nanoparticles (MNP- Fe3O4 conjugated with GA to increase water solubility of the drug and enhance its chemotherapeutic efficiency for pancreatic cancer.Methods: GA was conjugated with the MNP- Fe3O4 colloidal suspension by mechanical absorption polymerization to construct GA-loaded MNP- Fe3O4, which acted as a drug delivery system.Results: Combination therapy with GA and MNP- Fe3O4 induced remarkable improvement in anticancer activity, which was demonstrated by optical microscopic observations, MTT assay, and nuclear DAPI staining. Furthermore, the possible signaling pathway was explored by Western blot. In Capan-1 pancreatic cancer cells, our observations demonstrated that this strategy could enhance potential anticancer efficiency by inducing apoptosis. The mechanisms of the synergistic effect may be due to reducing protein expression of Bcl-2 and enhancing that of Bax, caspase 9, and caspase 3.Conclusion: These findings demonstrate that a combination of GA and MNPs- Fe3O4 represents a promising approach to the treatment of pancreatic cancer.Keywords: gambogic acid, pancreatic cancer, magnetic nanoparticles, drug delivery system, apoptosis

  4. Direct Electrochemistry and Electrocatalysis of Horseradish Peroxidase Immobilized in a DNA/Chitosan-Fe3O4 Magnetic Nanoparticle Bio-Complex Film

    Directory of Open Access Journals (Sweden)

    Tingting Gu

    2014-02-01

    Full Text Available A DNA/chitosan-Fe3O4 magnetic nanoparticle bio-complex film was constructed for the immobilization of horseradish peroxidase (HRP on a glassy carbon electrode. HRP was simply mixed with DNA, chitosan and Fe3O4 nanoparticles, and then applied to the electrode surface to form an enzyme-incorporated polyion complex film. Scanning electron microscopy (SEM was used to study the surface features of DNA/chitosan/Fe3O4/HRP layer. The results of electrochemical impedance spectroscopy (EIS show that Fe3O4 and enzyme were successfully immobilized on the electrode surface by the DNA/chitosan bio-polyion complex membrane. Direct electron transfer (DET and bioelectrocatalysis of HRP in the DNA/chitosan/Fe3O4 film were investigated by cyclic voltammetry (CV and constant potential amperometry. The HRP-immobilized electrode was found to undergo DET and exhibited a fast electron transfer rate constant of 3.7 s−1. The CV results showed that the modified electrode gave rise to well-defined peaks in phosphate buffer, corresponding to the electrochemical redox reaction between HRP(Fe(III and HRP(Fe(II. The obtained electrode also displayed an electrocatalytic reduction behavior towards H2O2. The resulting DNA/chitosan/Fe3O4/HRP/glassy carbon electrode (GCE shows a high sensitivity (20.8 A·cm−2·M−1 toward H2O2. A linear response to H2O2 measurement was obtained over the range from 2 µM to 100 µM (R2 = 0.99 and an amperometric detection limit of 1 µM (S/N = 3. The apparent Michaelis-Menten constant of HRP immobilized on the electrode was 0.28 mM. Furthermore, the electrode exhibits both good operational stability and storage stability.

  5. Radical induced degradation of acetaminophen with Fe3O4 magnetic nanoparticles as heterogeneous activator of peroxymonosulfate

    International Nuclear Information System (INIS)

    Graphical abstract: - Highlights: • The APAP degradation exhibited a pseudo-first-order kinetics pattern well. • The Fe3O4 was stable without significant leaching of iron to water during reaction. • XPS and EPR results show that Fe2+-Fe3+ cycle was answerable for radical generation. • The removal of APAP is a result of oxidation due to both OH• and SO4−• . - Abstract: Magnetic nano-scaled particles Fe3O4 were studied for the activation of peroxymonosulfate (PMS) to generate active radicals for degradation of acetaminophen (APAP) in water. The Fe3O4 MNPs were found to effectively catalyze PMS for removal of APAP, and the reactions well followed a pseudo-first-order kinetics pattern (R2 > 0.95). Within 120 min, approximately 75% of 10 ppm APAP was accomplished by 0.2 mM PMS in the presence of 0.8 g/L Fe3O4 MNPs with little Fe3+ leaching (<4 μg/L). Higher Fe3O4 MNP dose, lower initial APAP concentration, neutral pH, and higher reaction temperature favored the APAP degradation. The production of sulfate radicals and hydroxyl radicals was validated through two ways: (1) indirectly from the scavenging tests with scavenging agents, tert-butyl alcohol (TBA) and ethanol (EtOH); (2) directly from the electron paramagnetic resonance (ESR) tests with 0.1 M 5,5-dimethyl-1-pyrrolidine N-oxide (DMPO). Plausible mechanisms on the radical generation from Fe3O4 MNP activation of PMS are proposed based on the results of radical identification tests and XPS analysis. It appeared that Fe2+-Fe3+ on the catalyst surface was responsible for the radical generation. The results demonstrated that Fe3O4 MNPs activated PMS is a promising technology for water pollution caused by contaminants such as pharmaceuticals

  6. One-pot hydrothermal synthesis of hollow Fe3O4 microspheres assembled with nanoparticles for lithium-ion battery anodes

    DEFF Research Database (Denmark)

    Liu, Yanguo; Wang, Xiaoliang; Ma, Wuming;

    2016-01-01

    Hollow Fe3O4 microspheres assembled with nanoparticles were successfully synthesized without the addition of any templates or subsequent treatments. When used as the anode materials for lithium-ion battery (LIB), the products showed good lithium storage properties, demonstrating their promising...

  7. A facile one-pot ultrasound assisted for an efficient synthesis of benzo[g]chromenes using Fe3O4/polyethylene glycol (PEG) core/shell nanoparticles.

    Science.gov (United States)

    Safaei-Ghomi, Javad; Eshteghal, Fahime; Shahbazi-Alavi, Hossein

    2016-11-01

    In this research, a general synthetic method for the synthesis of benzo[g]chromenes has been developed using Fe3O4/polyethylene glycol (PEG) core/shell nanoparticle under ultrasonic irradiations. Compared to the conventional methods, ultrasound procedure showed several advantages including mild reaction conditions, high yield products, short reaction times, reusability of the catalyst and little catalyst loading. PMID:27245961

  8. Size-dependent cytotoxicity of Fe3O4 nanoparticles induced by biphasic regulation of oxidative stress in different human hepatoma cells

    Directory of Open Access Journals (Sweden)

    Xie Y

    2016-07-01

    Full Text Available Yuexia Xie,1,2,* Dejun Liu,3,* Chenlei Cai,1,* Xiaojing Chen,1 Yan Zhou,1 Liangliang Wu,1 Yongwei Sun,3 Huili Dai,1,2 Xianming Kong,1,2 Peifeng Liu1,2 1Central Laboratory, 2State Key Laboratory of Oncogenes and Related Genes, Shanghai Cancer Institute, 3Department of Biliary-Pancreatic Surgery, Renji Hospital, School of Medicine, Shanghai Jiao Tong University, Shanghai, People’s Republic of China *These authors contributed equally to this work Abstract: The application of Fe3O4 nanoparticles (NPs has made great progress in the diagnosis of disease and in the drug delivery system for cancer therapy, but the relative mecha­nisms of potential toxicity induced by Fe3O4 have not kept pace with its development in the application, which has hampered its further clinical application. In this article, we used two kinds of human hepatoma cell lines, SK-Hep-1 and Hep3B, to investigate the cytotoxic effects and the involved mechanisms of small Fe3O4 NPs with different diameters (6 nm, 9 nm, and 14 nm. Results showed that the size of NPs effectively influences the cytotoxicity of hepatoma cells: 6 nm Fe3O4 NPs exhibited negligible cytotoxicity and 9 nm Fe3O4 NPs affected cytotoxicity via cellular mitochondrial dysfunction and by inducing necrosis mediated through the mitochondria-dependent intracellular reactive oxygen species generation. Meanwhile, 14 nm Fe3O4 NPs induced cytotoxicity by impairing the integrity of plasma membrane and promoting massive lactate dehydrogenase leakage. These results explain the detailed mechanism of different diameters of small Fe3O4 NPs-induced cytotoxicity. We anticipate that this study will provide different insights into the cytotoxicity mechanism of Fe3O4 NPs, so as to make them safer to use in clinical application. Keywords: hepatoma cells, nanoparticles, cytotoxicity, mechanism, oxidative stress

  9. Reversal of multidrug resistance by magnetic Fe3O4 nanoparticle copolymerizating daunorubicin and 5-bromotetrandrine in xenograft nude-mice

    Directory of Open Access Journals (Sweden)

    Baoan Chen

    2009-03-01

    Full Text Available Baoan Chen1,* Jian Cheng1,* Yanan Wu1, Feng Gao1, Wenlin Xu2, et al 1Department of Hematology;2Department of Hematology, The Affiliated People’s Hospital, Jiangsu University, Zhenjiang, PR China *These authors have contributed equally to this workAbstract: In this paper we establish the xenograft leukemia model with stable multidrug resistance in nude mice and to investigate the reversal effect of 5-bromotetrandrine (5-BrTet and magnetic nanoparticle of Fe3O4 (MNP-Fe3O4 combined with daunorubicin (DNR in vivo. Two subclones of K562 and K562/A02 cells were inoculated subcutaneously into the back of athymic nude mice (1 × 107 cells/each respectively to establish leukemia xenograft models. Drug-resistant and sensitive tumor-bearing nude mice were assigned randomly into five groups which were treated with normal saline; DNR; NP-Fe3O4 combined with DNR; 5-BrTet combined with DNR; 5-BrTet and MNP-Fe3O4 combined with DNR, respectively. The incidence of formation, growth characteristics, weight, and volume of tumors were observed. The histopathologic examination of tumors and organs were detected. For resistant tumors, the protein levels of Bcl-2, and BAX were detected by Western blot. Bcl-2, BAX, and caspase-3 genes were also detected. For K562/A02 cells xenograft tumors, 5-BrTet and MNP-Fe3O4 combined with DNR significantly suppressed growth of tumor. A histopathologic examination of tumors clearly showed necrosis of the tumors. Application of 5-BrTet and MNP-Fe3O4 inhibited the expression of Bcl-2 protein and upregulated the expression of BAX and caspase-3 proteins in K562/A02 cells xenograft tumor. It is concluded that 5-BrTet and MNP-Fe3O4 combined with DNR had a significant tumor-suppressing effect on a MDR leukemia cells xenograft model.Keywords: 5-bromotetrandrine, magnetic nanoparticle of Fe3O4, multidrug-resistance, xenograft model

  10. Superparamagnetic Fe3O4 Nanoparticles: Synthesis by Thermal Decomposition of Iron(III) Glucuronate and Application in Magnetic Resonance Imaging.

    Science.gov (United States)

    Patsula, Vitalii; Kosinová, Lucie; Lovrić, Marija; Ferhatovic Hamzić, Lejla; Rabyk, Mariia; Konefal, Rafal; Paruzel, Aleksandra; Šlouf, Miroslav; Herynek, Vít; Gajović, Srećko; Horák, Daniel

    2016-03-23

    Monodisperse superparamagnetic Fe3O4 nanoparticles coated with oleic acid were prepared by thermal decomposition of Fe(III) glucuronate. The shape, size, and particle size distribution were controlled by varying the reaction parameters, such as the reaction temperature, concentration of the stabilizer, and type of high-boiling-point solvents. Magnetite particles were characterized by transmission electron microscopy (TEM), as well as electron diffraction (SAED), X-ray diffraction (XRD), dynamic light scattering (DLS), and magnetometer measurements. The particle coating was analyzed by atomic absorption spectroscopy (AAS) and attenuated total reflection (ATR) Fourier transform infrared spectroscopy (FTIR) spectroscopy. To make the Fe3O4 nanoparticles dispersible in water, the particle surface was modified with α-carboxyl-ω-bis(ethane-2,1-diyl)phosphonic acid-terminated poly(3-O-methacryloyl-α-D-glucopyranose) (PMG-P). For future practical biomedical applications, nontoxicity plays a key role, and the PMG-P&Fe3O4 nanoparticles were tested on rat mesenchymal stem cells to determine the particle toxicity and their ability to label the cells. MR relaxometry confirmed that the PMG-P&Fe3O4 nanoparticles had high relaxivity but rather low cellular uptake. Nevertheless, the labeled cells still provided visible contrast enhancement in the magnetic resonance image. In addition, the cell viability was not compromised by the nanoparticles. Therefore, the PMG-P&Fe3O4 nanoparticles have the potential to be used in biomedical applications, especially as contrast agents for magnetic resonance imaging. PMID:26928653

  11. A comparative study for adsorption of lysozyme from aqueous samples onto Fe3O4 magnetic nanoparticles using different ionic liquids as modifier.

    Science.gov (United States)

    Kamran, Sedigheh; Absalan, Ghodratollah; Asadi, Mozaffar

    2015-12-01

    In this paper, nanoparticles of Fe3O4 as well as their modified forms with different ionic liquids (IL-Fe3O4) were prepared and used for adsorption of lysozyme. The mean size and the surface morphology of the nanoparticles were characterized by TEM, XRD and FTIR techniques. Adsorption studies of lysozyme were performed under different experimental conditions in batch system on different modified magnetic nanoparticles such as, lysozyme concentration, pH of the solution, and contact time. Experimental results were obtained under the optimum operational conditions of pH 9.0 and a contact time of 10 min when initial protein concentrations of 0.05-2.0 mg mL(-1) were used. The isotherm evaluations revealed that the Langmuir model attained better fits to the equilibrium data than the Freundlich model. The maximum obtained adsorption capacities were 370.4, 400.0 500.0 and 526.3 mg of lysozyme for adsorption onto Fe3O4 and modified magnetic nanoparticles by [C4MIM][Br], [C6MIM][Br] and [C8MIM][Br] per gram of adsorbent, respectively. The Langmuir adsorption constants were 0.004, 0.019, 0.024 and 0.012 L mg(-1) for adsorptions of lysozyme onto Fe3O4 and modified magnetic nanoparticles by [C4MIM][Br], [C6MIM][Br] and [C8MIM][Br], respectively. The adsorption capacity of lysozyme was found to be dependent on its chemical structure, pH of the solution, temperature and type of ionic liquid as modifier. The applicability of two kinetic models including pseudo-first order and pseudo-second order model was estimated. Furthermore, the thermodynamic parameters were calculated. Protein could desorb from IL-Fe3O4 nanoparticles by using NaCl solution at pH 9.5 and was reused.

  12. Preparation, characterization of Fe3O4 at TiO2 magnetic nanoparticles and their application for immunoassay of biomarker of exposure to organophosphorus pesticides

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, Xiao; Wang, Hongbo; Yang, Chunming; Du, Dan; Lin, Yuehe

    2013-03-15

    Novel Fe3O4 at TiO2 magnetic nanoparticles were prepared and developed for a new nanoparticle-based immunosensor for electrochemical quantification of organophosphorylated butyrylcholinesterase (BChE) in plasma, a specific biomarker of exposure to organophosphorus (OP) agents. The Fe3O4 at TiO2 nanoparticles were synthesized by hydrolysis of tetrabutyltitanate on the surface of Fe3O4 magnetic nanospheres, and characterized by attenuated total reflection Fourier-transform infrared spectra, transmission electron microscope and X-ray diffraction. The functional Fe3O4 at TiO2 nanoparticles were performed as capture antibody to selectively enrich phosphorylated moiety instead of phosphoserine antibody in the traditional sandwich immunoassays. The secondary recognition was served by quantum dots (QDs)-tagged anti-BChE antibody (QDs-anti-BChE). With the help of a magnet, the resulting sandwich-like complex, Fe3O4 at TiO2/OP-BChE/QDs-anti-BChE, was easily isolated from sample solutions and the released cadmium ions were detected on a disposable screen-printed electrode (SPE). The binding affinities were investigated by both surface plasmon resonance (SPR) and square wave voltammetry (SWV). This method not only avoids the drawback of unavailability of commercial OP-specific antibody but also amplifies detection signal by QDs-tags together with easy separation of samples by magnetic forces. The proposed immunosensor yields a linear response over a broad OP-BChE concentrations range from 0.02 to 10 nM, with detection limit of 0.01 nM. Moreover, the disposable nanoparticle-based immunosensor has been validated with human plasma samples. It offers a new method for rapid, sensitive, selective and inexpensive screening/evaluating exposure to OP pesticides.

  13. Reclamation of acid pickling waste: A facile route for preparation of single-phase Fe3O4 nanoparticle

    Science.gov (United States)

    Zhang, Wenxue; Lu, Bin; Tang, Huihui; Zhao, Jingxiang; Cai, Qinghai

    2015-05-01

    Using an alternative method of dropwise addition of iron salt in NaOH aqueous solution, nanocrystalline Fe3O4 materials were prepared from acid pickling waste as a starting material with ultrasonic enhancement and polyethylene glycol as a dispersant, as proved by XRD, TEM, TG-DSC and ICP-MS. The results showed that the Fe3O4 material was a well-crystallized magnetite with an average size of about 25 nm and purity 99.15%. Magnetic measurement revealed the nanocrystals were stronger superparamagnetic with a saturation magnetization of 82.1 emu/g.

  14. The synthesis and characterization of monodispersed chitosan-coated Fe3O4 nanoparticles via a facile one-step solvothermal process for adsorption of bovine serum albumin

    OpenAIRE

    Shen, Mao; Yu, Yujing; Fan, Guodong; Chen, Guang; Jin, Ying min; Tang, Wenyuan; Jia, Wenping

    2014-01-01

    Preparation of magnetic nanoparticles coated with chitosan (CS-coated Fe3O4 NPs) in one step by the solvothermal method in the presence of different amounts of added chitosan is reported here. The magnetic property of the obtained magnetic composite nanoparticles was confirmed by X-ray diffraction (XRD) and magnetic measurements (VSM). Scanning electron microscopy (SEM) and transmission electron microscopy (TEM) allowed the identification of spherical nanoparticles with about 150 nm in averag...

  15. 靶向治疗用Fe3O4及其白蛋白包被磁性纳米粒子的制备%Preparation Fe3O4 Nanoparticles and HAS-Coated Magnetite Nanoparticals for Tumor Target Therapy

    Institute of Scientific and Technical Information of China (English)

    谭家驹; 张春富; 冯彦林; 曹金全; 曹本洪; 尹端; 汪勇先

    2003-01-01

    目的制备用于肿瘤靶向治疗的Fe3O4及其白蛋白包被的磁性纳米粒子.方法采用部分还原法制备Fe3O4纳米粒子,通过微乳化方法制备了白蛋白包被的Fe3O4磁性纳米颗粒.结果Fe3O4粒径为10nm左右,X-射线粉末衍射分析显示Fe3O4纳米磁性微粒是典型的尖晶石构型;白蛋白包被的磁性纳米粒子直径在200nm左右.结论Fe3O4及其白蛋白包被的磁性纳米粒子适于用于肿瘤靶向治疗的进一步研究.%Objective:To prepare Fe3O4 magnetite nanoparticles and HSA- coated magnetite particles for the purpose of regional target therapy. Methods: To adopt partial reduction method to prepare the Fe3O4 nanoparticles:100 ml 0.01 mol/L Na2SO3 was added dropwise into 100 ml 0.06 mol/LFeCl3 solution under nitrogen gas flow.10%(V%) ammonia was added dropwise with rapid stirring until pH of the reaction solution reach 8. Heated at 70℃ with water bath for 15 min. Preparation of HAS- coated magnetite particles:To use microemulsion approach,with oleic acid as oil phase, mixture of HSA and magnetite solution as water phase and sp- 85 as emulsion agent.Results: Fe3O4 magnetite particles with about 10 nm in diameter and X - ray power diffraction show that the nanoparticles is γ- Fe2O3. HAS- coated Fe3O4 magnetite nanoparticles is characterized by TEM with diameter no more than 200 nm. Conclusions: Fe3O4 magnetite nanoparticles and HSA - coated magnetite particles is suitable for researching of regional target therapy.

  16. Reversal in multidrug resistance by magnetic nanoparticle of Fe3O4 loaded with adriamycin and tetrandrine in K562/A02 leukemic cells

    Directory of Open Access Journals (Sweden)

    Baoan Chen

    2008-06-01

    Full Text Available Baoan Chen1,5, Qian Sun1,5, Xuemei Wang2, Feng Gao1, Yongyuan Dai1, Yan Yin1, Jiahua Ding1, Chong Gao1, Jian Cheng1, Jingyuan Li2, Xinchen Sun1, Ningna Chen1, Wenlin Xu3, Huiling Shen3, Delong Liu41Department of Hematology, Zhongda Hospital, Southeast University, Nanjing, China; 2State Key Lab of Bioelectronics(Chien-Shiung Wu Laboratory, Southeast University, Nanjing 210096, China; 3Department of Hematology, The First People’s Hospital of Zhenjiang, Zhenjiang, China; 4Westchester Medical Center, New York Medical College, NY, USA; 5These authors have contributed equally to this work.Abstract: Drug resistance is a primary hindrance for efficiency of chemotherapy. To investigate whether Fe3O4-magnetic nanoparticles (Fe3O4-MNPs loaded with adriamycin (ADM and tetrandrine (Tet would play a synergetic reverse role in multidrug resistant cell, we prepared the drug-loaded nanoparticles by mechanical absorption polymerization to act with K562 and one of its resistant cell line K562/A02. The survival of cells which were cultured with these conjugates for 48 h was observed by MTT assay. Using cells under the same condition described before, we took use of fluorescence microscope to measure fluorescence intensity of intracellular ADM at an excitation wavelength of 488 nm. P-glycoprotein (P-gp was analyzed with flow cytometer. The expression of mdr1 mRNA was measured by RT-PCR. The results showed that the growth inhibition efficacy of both the two cells increased with augmenting concentrations of Fe3O4-MNPs which were loaded with drugs. No linear correlation was found between fluorescence intensity of intracellular adriamycin and augmenting concentration of Fe3O4-MNPs. Tet could downregulate the level of mdr-1 gene and decrease the expression of P-gp. Furthermore, Tet polymerized with Fe3O4-MNPs reinforced this downregulation, causing a 100-fold more decrease in mdr1 mRNA level, but did not reduce total P-gp content. Our results suggest that Fe3O4-MNPs

  17. Characteristics of magnetic labeling on liver tumors with anti-alpha-fetoprotein-mediated Fe3O4 magnetic nanoparticles.

    Science.gov (United States)

    Huang, Kai-Wen; Chieh, Jen-Jie; Horng, Herng-Er; Hong, Chin-Yih; Yang, Hong-Chang

    2012-01-01

    For preoperative and intraoperative detection of tumor distribution, numerous multimodal contrast agents, such as magnetic nanoparticles (MNPs) with several examination indicators, are currently in development. However, complex materials, configuration, and cost are required for multimodal contrast agents, accompanied by a high possibility of toxicity and low popularity in clinics. Nevertheless, the magnetic labeling of MNPs using bioprobes should be feasible not only in preoperative magnetic resonance imaging (MRI), but also in intraoperative examination based on other magnetic properties. In this study, anti-alpha-fetoprotein (AFP)-mediated Fe(3)O(4) MNPs, injected into mice with liver tumors, were used to examine the characteristics of magnetic labeling. Using MRI and scanning superconducting-quantum-interference-device biosusceptometry (SSB), based on alternating current (AC) susceptibility, the magnetic labeling occurred significantly on the first day post-injection of anti-AFP magnetic fluid (MF), and then decreased over time. However, for both MF without antibodies and an anti-carcinoembryonic antigen MF, no magnetic labeling occured on the first day of their respective post-injection. The favorable agreement indicates that magnetic labeling possesses two magnetic characteristics: distortion of the imaging field and AC susceptibility. In addition, the results of the biopsy tests, anti-AFP staining, and Prussian blue staining show the same dynamics as those of magnetic methodologies and prove that bound MNPs on tumor tissue are rotatable by an AC magnetic field to express AC susceptibility. Therefore, with the simple configuration of antibody-mediated MNPs, magnetic labeling is also feasible for intraoperative examinations using SSB with high mobility and sensitivity. PMID:22787394

  18. Co-encapsulation of magnetic Fe3O4 nanoparticles and doxorubicin into biodegradable PLGA nanocarriers for intratumoral drug delivery

    Directory of Open Access Journals (Sweden)

    Jia Y

    2012-03-01

    Full Text Available Yanhui Jia1, Mei Yuan1, Huidong Yuan1, Xinglu Huang2, Xiang Sui1, Xuemei Cui1, Fangqiong Tang2, Jiang Peng1, Jiying Chen1, Shibi Lu1, Wenjing Xu1, Li Zhang1, Quanyi Guo11Institute of Orthopedics, General Hospital of the Chinese People's Liberation Army, Beijing, People's Republic of China; 2Laboratory of Controllable Preparation and Application of Nanomaterials, Technical Institute of Physics and Chemistry, Chinese Academy of Sciences, Beijing, People's Republic of ChinaAbstract: In this study, the authors constructed a novel PLGA [poly(D,L-lactic-co-glycolic acid]-based polymeric nanocarrier co-encapsulated with doxorubicin (DOX and magnetic Fe3O4 nanoparticles (MNPs using a single emulsion evaporation method. The DOX-MNPs showed high entrapment efficiency, and they supported a sustained and steady release of DOX. Moreover, the drug release was pH sensitive, with a faster release rate in an acidic environment than in a neutral environment. In vitro, the DOX-MNPs were easily internalized into murine Lewis lung carcinoma cells and they induced apoptosis. In vivo, the DOX-MNPs showed higher antitumor activity than free DOX solution. Furthermore, the antitumor activity of the DOX-MNPs was higher with than without an external magnetic field; they were also associated with smaller tumor volume and a lower metastases incidence rate. This work may provide a new modality for developing an effective drug delivery system.Keywords: antitumor activity, external magnetic field, intratumoral injection, apoptosis, Lewis lung carcinoma

  19. Magnetic adsorbent constructed from the loading of amino functionalized Fe3O4 on coordination complex modified polyoxometalates nanoparticle and its tetracycline adsorption removal property study

    Science.gov (United States)

    Ou, Jinzhao; Mei, Mingliang; Xu, Xinxin

    2016-06-01

    A magnetic polyoxometalates based adsorbent has been synthesized successfully through the loading of amino functionalized Fe3O4 (NH2-Fe3O4) on nanoparticle of a coordination complex modified polyoxometalates (CC/POMNP). FTIR illustrate there exist intense hydrogen bonds between NH2-Fe3O4 and CC/POMNP, which keep the stability of this adsorbent. At room temperature, this adsorbent exhibits ferromagnetic character with saturation magnetization of 8.19 emu g-1, which provides prerequisite for fast magnetic separation. Water treatment experiment illustrates this POM based magnetic adsorbent exhibits high adsorption capacity on tetracycline. The adsorption process can be described well with Temkin model, which illustrates the interaction between adsorbent and tetracycline plays the dominated role in tetracycline removal. The rapid, high efficient tetracycline adsorption ability suggests this POM based magnetic adsorbent exhibits promising prospect in medical and agriculture waste water purification. A magnetic polyoxometalates based adsorbent, which exhibits excellent tetracycline adsorption removal property has been synthesized through the loading of NH2-Fe3O4 on coordination complex modified polyoxometalates

  20. Biodesel Production from Pseudomonas Fluorescens Lp1 Lipase Immobilized on Amino-silane Modified Super Paramagnetic Fe3O4 Nanoparticles

    International Nuclear Information System (INIS)

    An extracellular lipase from Pseudomonas fluorescens Lp1 isolated from oil contaminated soil was immobilized onto amino silane modified superparamagnetic Fe3O4 nanoparticles. The magnetic nanoparticles, magnetite was synthesized chemically by co-precipitation and characterized by Scanning Electron Microscopy (SEM), Fourier Transformed Infrared Spectroscopy (FT-IR) and Powder X-ray diffraction studies (XRD). The structure of the synthesized magnetic nanoparticles was uniform, spherical and the size was determined around 31 nm by powder XRD. The biodiesel production mixture was prepared by addition of waste cooking oil, lipase immobilized magnetite and methanol. The transesterified products were analyzed by Gas Liquid chromatography-Mass spectroscopy (GC-MS). The methyl esters such as Oxiraneundecanoic acid, 3-pentyl-methyl ester, Hexadecanoic acid, methyl ester and 10-Octadecenoic acid, methyl ester were obtained. The study experimentally proved the use of amino silane modified superparamagnetic Fe3O4 nanoparticles in biodiesel production from waste cooking oil.

  1. Biodesel Production from Pseudomonas Fluorescens Lp1 Lipase Immobilized on Amino-silane Modified Super Paramagnetic Fe3O4 Nanoparticles

    Science.gov (United States)

    Kanimozhi, S.; Perinbam, K.

    2013-04-01

    An extracellular lipase from Pseudomonas fluorescens Lp1 isolated from oil contaminated soil was immobilized onto amino silane modified superparamagnetic Fe3O4 nanoparticles. The magnetic nanoparticles, magnetite was synthesized chemically by co-precipitation and characterized by Scanning Electron Microscopy (SEM), Fourier Transformed Infrared Spectroscopy (FT-IR) and Powder X-ray diffraction studies (XRD). The structure of the synthesized magnetic nanoparticles was uniform, spherical and the size was determined around 31 nm by powder XRD. The biodiesel production mixture was prepared by addition of waste cooking oil, lipase immobilized magnetite and methanol. The transesterified products were analyzed by Gas Liquid chromatography-Mass spectroscopy (GC-MS). The methyl esters such as Oxiraneundecanoic acid, 3-pentyl-methyl ester, Hexadecanoic acid, methyl ester and 10-Octadecenoic acid, methyl ester were obtained. The study experimentally proved the use of amino silane modified superparamagnetic Fe3O4 nanoparticles in biodiesel production from waste cooking oil.

  2. Optimization of the preparation condition of Fe3O4 nanoparticle by BP nerve network%利用BP神经网络算法优化纳米Fe3O4的合成工艺

    Institute of Scientific and Technical Information of China (English)

    崔升; 沈晓冬; 林本兰

    2005-01-01

    采用液相共沉淀法制备出了纳米级Fe3O4颗粒,并利用正交设计法对实验进行设计,据此找出最佳实验条件为Fe3O4的晶化温度为90℃,Fe3+/Fe2+的比例为1:2和制备Fe3O4的晶化时间为45min.此时制得的纳米粉体平均粒径可达10~20nm,并利用BP神经网络分析了Fe3+/Fe2+的比例、晶化温度和晶化时间等对粒子粒径的影响规律.

  3. Preparation of Fe3O4 nano-particles and study of microcalorimetry%Fe3O4纳米粒子的制备及微量热应用研究

    Institute of Scientific and Technical Information of China (English)

    李曦; 靳艳巧; 丁玲; 张超灿

    2004-01-01

    采用化学共沉淀法制备出了可达到纳米级分散的Fe3O4纳米粒子,讨论了产物的结构,粒径分布、磁性能及制备过程中工艺条件的控制,并利用等温微量热检测仪测量了Fe3O4和油酸-乙醇溶液之间的吸附热,分析了两者之间的吸附机理.

  4. 血管生成靶向纳米粒子c(RGDyK)@SiO2@Fe3O4的合成及生物性能%Preparation and biological characterization of c(RGDyK)@SiO2@Fe3O4 nanoparticles targeted for angiogenesis

    Institute of Scientific and Technical Information of China (English)

    孙鹏飞; 曹向荣; 朱浩; 焦宗宪; 张锋伟; 颉克蓉

    2012-01-01

    背景:SiO2 含有较多的羟基官能团,可进一步功能化而与靶向性配体相偶联,从而拓展Fe3O4@SiO2 纳米粒子在生物医药领域的应用.目的:探讨靶向性纳米粒子c(RGDyK)@SiO2@Fe3O4)的合成方法,并对其性能进行测试.方法:采用一壶化学共沉淀法合成油酸修饰的疏水性Fe3O4 纳米粒子,采用反相微乳液法合成生物相容性Fe3O4@SiO2 复合纳米粒子;以3-氨丙基三乙氧基硅烷为偶联剂将复合粒子中SiO2 表面的羟基氨基化、醛基化,加入1.0 mg c(RGDyK)多肽,超声震荡下反应生成c(RGDyK)@SiO2@Fe3O4 纳米粒子.将Fe3O4@SiO2或c(RGDyK)@SiO2@Fe3O4 与人脐静脉细胞融合细胞(EA.hy926)共培养24,48,72 h 进行检测.结果与结论:实验合成的Fe3O4@SiO2 复合纳米粒子的平均粒径为40 nm,应用3-氨丙基三乙氧基硅烷可将c(RGDyK)成功耦合于复合粒子的SiO2 表面.Fe3O4@SiO2 或c(RGDyK)@SiO2@Fe3O4 与EA.hy926 共培养24 h,EA.hy926 细胞活性明显增高(P0.05).电镜观察发现,EA.hy926 细胞对靶向性c(RGDyK)@SiO2@Fe3O4 粒子的吞噬能力明显强于非靶向性Fe3O4@SiO2 粒子.说明实验合成的c(RGDyK)@SiO2@Fe3O4 纳米粒子具有良好的生物相容性、超顺磁性及较高的血管内皮细胞靶向性,是一种优良的生物材料.%BACKGROUND: SiO2 has a great amount of hydroxyl groups, It can be further functionalized to couple targeting ligand in order to expand the application of Fe3O4@SiO2 nanoparticles in the biomedical field. OBJECTIVE: To investigate the preparation method of targeted c(RGDyK)@SiO2@Fe3O4 nanoparticles (NPs) and its property testing. METHODS: Oleic acid-loaded hydrophobic Fe3O4 NPs were prepared via a pot chemical coprecipitation, and the biocompatible Fe3O4@SiO2 compound NPs were synthesized with a reverse microemulsion. By means of the 3-aminopropyl triethoxysilan (APTMS) as couplant, the hydroxyl groups of SiO2 surface in compound particles were changed into amino or aldehyde groups. Then 1

  5. The influence of oxidation process on exchange bias in egg-shaped FeO/Fe3O4 core/shell nanoparticles

    Science.gov (United States)

    Leszczyński, Błażej; Hadjipanayis, George C.; El-Gendy, Ahmed A.; Załęski, Karol; Śniadecki, Zbigniew; Musiał, Andrzej; Jarek, Marcin; Jurga, Stefan; Skumiel, Andrzej

    2016-10-01

    Egg-shaped nanoparticles with a core-shell morphology were synthesized by thermal decomposition of an iron oleate complex. XRD and M(T) magnetic measurements confirmed the presence of FeO (wustite) and Fe3O4 (magnetite) phases in the nanoparticles. Oxidation of FeO to Fe3O4 was found to be the mechanism for the shell formation. As-made nanoparticles exhibited high values of exchange bias at 2 K. Oxidation led to decrease of exchange field from 2880 Oe (in as-made sample) to 330 Oe (in oxidized sample). At temperatures higher than the Néel temperature of FeO (200 K) there was no exchange bias. An interesting observation was made showing the exchange field to be higher than the coercive field at temperatures close to magnetite's Verwey transition.

  6. High cycling stability of anodes for lithium-ion batteries based on Fe3O4 nanoparticles and poly(acrylic acid) binder

    Science.gov (United States)

    Maroni, F.; Gabrielli, S.; Palmieri, A.; Marcantoni, E.; Croce, F.; Nobili, F.

    2016-11-01

    Fe3O4 nanoparticles synthesized by a base catalyzed method are tested as anode material for Li-ion batteries. The pristine nanoparticles are morphologically characterized showing an average size of 11 nm. Electrodes are prepared using high-molecular weight Poly (acrylic acid) as improved binder and ethanol as low cost and environmentally friendly solvent. The evaluation of electrochemical properties shows high specific capacity values of 857 mA hg-1 after 200 cycles at a specific current of 462 mAg-1, as well as an excellent rate capability with specific current values up to 18480 mAg-1. To the best of our knowledge, this is the first report of Fe3O4 nanoparticles cycling with PAA as binder.

  7. Synergistic effect of the combination of triethylene-glycol modified Fe3O4 nanoparticles and ultrasound wave on MCF-7 cells

    Science.gov (United States)

    Ebrahimi Fard, Ali; Zarepour, Atefeh; Zarrabi, Ali; Shanei, Ahmad; Salehi, Hossein

    2015-11-01

    Cancer is a group of disease characterized by uncontrolled growth and spread of abnormal cells in the body. The clinical treatments for cancer include surgery, chemotherapy and radiotherapy. Currently, employing new approaches for treatment has attracted more attentions. One of these approaches is sonodynamic therapy, which is an analogous approach based on the synergistic effect of ultrasound and a chemical component referred to as sonosensitizer. Recent years applications of nanotechnology have witnessed a tremendous expansion of research in medicine especially in treatment of cancers. The combination of sonodynamic therapy and nanotechnology can introduce a new way for cancer therapy. In this study, we used therapeutic ultrasonic waves with intensity of 1 MHz and different concentrations of Fe3O4 nanoparticles, as sonosensitizer, to investigate their combination effect on MCF-7 cell line. Briefly, we divided cells into four different groups; control, cells which got in touch with nanoparticles, cells that with exposure to ultrasound waves and cells which were influenced with combination of nanoparticles and ultrasonic waves. Finally, cell viability assay was used for detection of cytotoxicity effects. Experimental results revealed a significant decrease in viability of cells, which were affected by the combined action of ultrasound field and Fe3O4 nanoparticles, compared to the separate exposure of Fe3O4 nanoparticles or ultrasonic field. The synergic effect of ultrasound waves and Fe ions might be due to the production of toxic free radicals.

  8. PREPARATION AND CHARACTERIZATION OF PVP-b-PLA MODIFIED Fe3O4 MAGNETIC NANOPARTICLES%PVP-b-PLA 修饰 Fe3O4 磁性纳米粒子的制备与表征

    Institute of Scientific and Technical Information of China (English)

    熊雷; 姜宏伟; 王迪珍

    2008-01-01

    通过硅烷偶联剂与 Fe3O4 磁性纳米粒子偶合在其表面引入C=C端基,进一步与N-乙烯基吡咯烷酮(NVP)加成聚合制备含端羟基 PVP 包裹的磁体.再引发丙交酯(LA)开环聚合制得 PVP-b-PLA 修饰的 Fe3O4 纳米粒子.通过XRD、GPC、FTIR、SEM、TG、DSC 和激光粒度仪等.对产物进行分析和表征,结果表明,纳米 Fe3O4 与 PVP 以及 PVP 与 PLA 之间均为化学键联,PVP 和 PLA 是以嵌段共聚物的形式存在且两者之间存在明显的微相分离,纳米 Fe3O4 表面聚合物包覆率为35%,厚度约13 nm.此外,该PVP-b-PLA包覆的磁性纳米粒子比饱和磁化强度为53 emu/g,与未包覆相比下降约25%.

  9. 超顺磁Fe3O4@PDA核-壳结构纳米粒子的制备及表征%Synthesis and Characterization of Superparamagnetic Fe3O4@PDA Core-Shell Structure Nanoparticles

    Institute of Scientific and Technical Information of China (English)

    骆东升; 王新灵

    2016-01-01

    利用多元醇高温热解法和溶液氧化法制备超顺磁四氧化三铁聚多巴胺核-壳结构纳米粒子(Fe3O4@PDA).采用X射线衍射(XRD)、透射电子显微镜(TEM)、动态光散射(DLS)、傅里叶转换红外光谱(FT-IR)和热重分析(TG)等对Fe3O4@PDA的结构、形貌和组成进行表征.采用综合物性测试系统(PPMS)对样品的磁性能进行袁征.结果表明:Fe3O4@PDA的尺寸可以通过氨水与多巴胺的物质的量之比和反应时间进行调控;当Fe3O4@PDA中Fe3O4的质量分数约为5%时,具有超顺磁性,磁饱和强度为3.8 emu/g,比理论值高出36%.

  10. Investigation of magnetic field enriched surface enhanced resonance Raman scattering performance using Fe3O4@Ag nanoparticles for malaria diagnosis

    Science.gov (United States)

    Yuen, Clement; Liu, Quan

    2014-03-01

    Recently, we have demonstrated the magnetic field-enriched surface-enhanced resonance Raman spectroscopy (SERRS) of β-hematin by using nanoparticles with iron oxide core and silver shell (Fe3O4@Ag) for the potential application in the early malaria diagnosis. In this study, we investigate the dependence of the magnetic field-enriched SERRS performance of β-hematin on the different core and shell sizes of the Fe3O4@Ag nanoparticles. We note that the core and shell parameters are critical in the realization of the optimal magnetic field-enrich SERRS β-hematin signal. These results are consistent with our simulations that will guide the optimization of the magnetic SERRS performance for the potential early diagnosis in the malaria disease.

  11. Heterogeneous electro-Fenton oxidation of azo dye methyl orange catalyzed by magnetic Fe3O4 nanoparticles.

    Science.gov (United States)

    Jiang, Hao; Sun, Yabing; Feng, Jingwei; Wang, Jian

    2016-01-01

    Azo dye methyl orange (MO) degradation by heterogeneous electro-Fenton (EF) with a magnetic nano-Fe3O4 catalyst was investigated. In this study, Fe3O4 was synthesized by a coprecipitation method and characterized by X-ray diffraction and scanning electron microscopy. The influences of the main operating parameters such as current density, pH, catalyst dosage and aeration rate were studied. The results revealed that higher current density, catalyst dosage and aeration rate facilitated the degradation of MO, whereas the degradation efficiency of MO was decreased with an increase in the initial pH. After 90 min EF process, the volume of 500 mL, the initial concentration of 50 mg L(-1) MO solution could be degraded by 86.6% with the addition of 1 g L(-1) Fe3O4 under the current density of 10 mA cm(-2) and pH 3, compared with 69.5% for the electrolytic process alone. Meanwhile, a total organic carbon removal of 32% was obtained, up to 35.5 mg L(-1) accumulated H2O2 and less than 3.5 mg L(-1) Fe leaching were detected. Moreover, based on the results of natural bond orbital (at B3LYP/6-311G (d, p)) and liquid chromatograph-triple quadrupole mass spectrometer analysis, nine intermediates were identified and the proposed degradation pathways were investigated. PMID:27642831

  12. Novel Functionalized Polythiophene-Coated Fe3O4 Nanoparticles for Magnetic Solid-Phase Extraction of Phthalates

    Directory of Open Access Journals (Sweden)

    Siti Nor Atika Baharin

    2016-04-01

    Full Text Available Poly(phenyl-(4-(6-thiophen-3-yl-hexyloxy-benzylidene-amine (P3TArH was successfully synthesized and coated on the surface of Fe3O4 magnetic nanoparticles (MNPs. The nanocomposites were characterized by Fourier transform infra-red (FTIR, X-ray diffractometry (XRD, Brunauer-Emmett-Teller (BET surface area analysis, analyzer transmission electron microscopy (TEM and vibrating sample magnetometry (VSM. P3TArH-coated MNPs (MNP@P3TArH showed higher capabilities for the extraction of commonly-used phthalates and were optimized for the magnetic-solid phase extraction (MSPE of environmental samples. Separation and determination of the extracted phthalates, namely dimethyl phthalate (DMP, diethyl phthalate (DEP, dipropyl phthalate (DPP, dibutyl phthalate (DBP, butyl benzyl phthalate (BBP, dicyclohexyl phthalate (DCP, di-ethylhexyl phthalate (DEHP and di-n-octyl phthalate (DNOP, were conducted by a gas chromatography-flame ionization detector (GC-FID. The best working conditions were as follows; sample at pH 7, 30 min extraction time, ethyl acetate as the elution solvent, 500-µL elution solvent volumes, 10 min desorption time, 10-mg adsorbent dosage, 20-mL sample loading volume and 15 g·L−1 concentration of NaCl. Under the optimized conditions, the analytical performances were determined with a linear range of 0.1–50 µg·L−1 and a limit of detection at 0.08–0.468 µg·L−1 for all of the analytes studied. The intra-day (n = 7 and inter-day (n = 3 relative standard deviations (RSD% of three replicates were each demonstrated in the range of 3.7–4.9 and 3.0–5.0, respectively. The steadiness and reusability studies suggested that the MNP@P3TArH could be used up to five cycles. The proposed method was executed for the analysis of real water samples, namely commercial bottled mineral water and bottled fresh milk, whereby recoveries in the range of 68%–101% and RSD% lower than 7.7 were attained.

  13. Characteristics of magnetic labeling on liver tumors with anti-alpha-fetoprotein-mediated Fe3O4 magnetic nanoparticles

    Directory of Open Access Journals (Sweden)

    Huang KW

    2012-06-01

    Full Text Available Kai-Wen Huang,1 Jen-Jie Chieh,2 Herng-Er Horng,2 Chin-Yih Hong,3 Hong-Chang Yang41Department of Surgery and Hepatitis Research Center, National Taiwan University Hospital, Taipei, 2Institute of Electro-optical Science and Technology, National Taiwan Normal University, Taipei, 3Graduate Institute of Biomedical Engineering, National Chung Hsing University, Taichung, 4Department of Physics, National Taiwan University, Taipei, TaiwanAbstract: For preoperative and intraoperative detection of tumor distribution, numerous multimodal contrast agents, such as magnetic nanoparticles (MNPs with several examination indicators, are currently in development. However, complex materials, configuration, and cost are required for multimodal contrast agents, accompanied by a high possibility of toxicity and low popularity in clinics. Nevertheless, the magnetic labeling of MNPs using bioprobes should be feasible not only in preoperative magnetic resonance imaging (MRI, but also in intraoperative examination based on other magnetic properties. In this study, anti-alpha-fetoprotein (AFP-mediated Fe3O4 MNPs, injected into mice with liver tumors, were used to examine the characteristics of magnetic labeling. Using MRI and scanning superconducting-quantum-interference-device biosusceptometry (SSB, based on alternating current (AC susceptibility, the magnetic labeling occurred significantly on the first day post-injection of anti-AFP magnetic fluid (MF, and then decreased over time. However, for both MF without antibodies and an anti-carcinoembryonic antigen MF, no magnetic labeling occured on the first day of their respective post-injection. The favorable agreement indicates that magnetic labeling possesses two magnetic characteristics: distortion of the imaging field and AC susceptibility. In addition, the results of the biopsy tests, anti-AFP staining, and Prussian blue staining show the same dynamics as those of magnetic methodologies and prove that bound MNPs on

  14. Preparation and Analysis of Fe3O4 Magnetic Nanoparticles Used as Targeted-drug Carriers%磁性Fe3O4纳米粒子用作靶向药物载体的制备及分析

    Institute of Scientific and Technical Information of China (English)

    赵原壁; 邱祖民; 黄佳英

    2008-01-01

    Fe3O4 magnetic nanoparticles were prepared by the aqueous co-precipitation of FeCl3·6H2O and FeCl2·4H2O with addition of ammonium hydroxide. The conditions for the preparation of Fe3O4 magnetic nanoparticles were optimized, and Fe3O4 magnetic nanoparticles obtained were characterized systematically by means of transmission electron microscope (TEM), dynamic laser scattering analyzer (DLS) and X-ray diffraction (XRD). The results revealed that the magnetic nanoparticles were cubic shaped and dispersive, with narrow size distribution and average diameter of 11.4nm. It was found that the homogeneous variation of pH value in the solution via the control on the dropping rate of aqueous ammonia played a critical role in size distribution. The magnetic response of the product in the magnetic field was also analyzed and evaluated carefully. A 32.6 mT magnetic field which is produced by four ferromagnets was found to be sufficient to excite the dipole moments of 0.05g Fe3O4 powder 2cm far away from the ferromagnets. In conclusion, the Fe3O4 magnetic nanoparticles with excellent properties were competent for the magnetic carriers of targeted-drug in future application.

  15. Preparation and biological application of magnetic Fe3O4/carboxyl functional chitosan composite nanoparticle%Fe3O4/羧基改性壳聚糖复合纳米粒子的制备、表征及生物学应用

    Institute of Scientific and Technical Information of China (English)

    李桂银; 杨栋梁; 黄可龙; 蒋玉仁

    2009-01-01

    采用氧化水热法,以H2O2为氧化剂制备了磁性Fe3O4纳米颗粒.以磁性Fe3O4为核,通过反相悬浮聚合法对Fe3O4颗粒表面进行改性,在碳二亚胺的活化作用下,与壳聚糖衍生物-α-酮戊二酸缩壳聚糖(KCTS)反应制备了表面含有一定羧基的磁性Fe3O4/KCTS纳米粒子.经XRD、TEM、VSM、IR、TGA等手段对复合材料进行了表征及性能研究.结果表明,该磁性Fe3O4/KCTS纳米粒子的平均粒径为26nm,比饱和磁化强度为24.8A·m2/kg.其性能优良,具备超顺磁性,能很好的应用于生物分离,蛋白吸附等领域.%The magnetic Fe3O4/carboxyl functional chitosan composite nanoparticles have been prepared by the covalent binding of chitosan alpha-ketoglutaric acid (KCTS) onto the surface of FesO4 magnetic nanoparticles via earbodiimide activation. Transmission electron microscopy (TEM) showed that the Fe3O4/KCTS nanoparti-cles were regular sphere with a mean diameter of 26 nm. X-ray diffraction (XRD) patterns indicated that the FesO4 nanoparticles were pure FesO4 with a spinel structure, and the binding of KCTS did not result in a phase change. The binding of KCTS to the Fe3O4 nanoparticles was also demonstrated by the measurement of therrno-gravimetric analysis (TGA) and Fourier transforrm infrared (FTIR) spectra. Magnetic measurement revealed that the saturated magnetization of the Fe3O4/KCTS nanoparticles reached 24.8A · m2/kg and the nanoparticles showed the characteristics of superparamagnetism. And the nanoparticles were applied successfully to bio-sepa-rations and bio-adsorption.

  16. A Micro Rectangular-Shaped Long-Period Fiber Grating Coated With Fe3O4 Nanoparticle Thin Overlay For Magnetic Sensing

    OpenAIRE

    Sheng-Feng Wang; Chia-Chin Chiang

    2015-01-01

    In this paper, we provide a novel micro rectangular-shaped long-period fiber grating (MRSLPFG) coated with Fe3O4 nanoparticles as the sensing material and packaged in polydimethylsiloxane (PDMS) for magnetic sensing application. The micro rectangular-shaped grating structures are fully dip coated with the magnetic fluid and heated to form a thin solid film. This thin overlay is used as the sensing media to measure the external magnetic flux density parallel to the optical fiber axis. Accordin...

  17. Effect of magnetic nanoparticles of Fe3O4 and 5-bromotetrandrine on reversal of multidrug resistance in K562/A02 leukemic cells

    Directory of Open Access Journals (Sweden)

    Jian Cheng

    2009-09-01

    Full Text Available Jian Cheng1*, Weiwei Wu1*, Bao-an Chen1, Feng Gao1, Wenlin Xu2, Chong Gao1, Jiahua Ding1, Yunyu Sun1, Huihui Song1, Wen Bao1, Xinchen Sun3, Cuirong Xu1, Wenji Chen1, Ningna Chen1, Lijie Liu4, Guohua Xia1, Xiaomao Li5, Xuemei Wang61Department of Hematology, 3Department of Oncology, The Afiliated Zhongda Hospital, Southeast University, Nanjing, People’s Republic of China; 2Department of Hematology, The First People’s Hospital of Zhengjiang, Zhenjiang, People’s Republic of China; 4Institution of Physiology, 6State Key Lab of Bioelectronics (Chien-Shiung Wu Laboratory, Southeast University, Nanjing, People’s Republic of China; 5Department of Physics, University of Saarland, Saarbruechen, Germany; *These authors have contributed equally to this workAbstract: This study aims to evaluate the multidrug resistance (MDR reversal activity by magnetic nanoparticles of Fe3O4 (MNPs-Fe3O4 and 5-bromotetrandrine (BrTet MDR cell line K562/A02 solitarily or symphysially. The proliferation of K562 and K562/A02 cells and the cytotoxicity on peripheral blood mononuclear cells (PMBCs were evaluated by MTT assay. Cellular accumulation of daunorubicin (DNR was analyzed by flow cytometry. Real-time polymerase chain reaction and Western blotting analyses were performed to examine the mRNA and protein levels of mdr1, respectively. The results showed that the combination of MNPs-Fe3O4 and BrTet with effective concentrations significantly increased cytotoxicity against MDR cell line K562/A02. Both BrTet and MNPs-Fe3O4 increased the intracellular DNR accumulation in the K562/A02 cell line, and downregulated the level of mdr1 gene and expression of P-glycoprotein. Furthermore, the combination did not have significant cytotoxicity in PMBCs. We propose that MNPs-Fe3O4 conjugated with DNR and BrTet probably have synergetic effects on MDR reversal.Keywords: magnetic nanoparticles of Fe3O4, 5-bromotetrandrine, multidrug resistance K562/A02

  18. Daunorubicin-loaded magnetic nanoparticles of Fe3O4 overcome multidrug resistance and induce apoptosis of K562-n/VCR cells in vivo

    Directory of Open Access Journals (Sweden)

    Bao-an Chen

    2009-09-01

    Full Text Available Bao-an Chen1, Bin-bin Lai1, Jian Cheng1, Guo-hua Xia1, Feng Gao1, Wen-lin Xu2, Jia-hua Ding1, Chong Gao1, Xin-chen Sun3, Cui-rong Xu1, Wen-ji Chen1, Ning-na Chen1, Li-jie Liu4, Xiao-mao Li5, Xue-mei Wang61Department of Hematology, 3Department of Oncology, the Affiliated Zhongda Hospital, Clinical Medical School, Southeast University, Nanjing, People’s Republic of China; 2Department of Hematology, the Affiliated People’s Hospital, Jiangsu University, Zhenjiang, People’s Republic of China; 4Institution of Physiology, 6State Key Lab of Bioelectronics (Chien-shiung Wu Laboratory, Southeast University, Nanjing, People’s Republic of China; 5Department of Physics, University of Saarland, Saarbruechen, GermanyAbstract: Multidrug resistance (MDR is a major obstacle to cancer chemotherapy. We evaluated the effect of daunorubicin (DNR-loaded magnetic nanoparticles of Fe3O4 (MNPs-Fe3O4 on K562-n/VCR cells in vivo. K562-n and its MDR counterpart K562-n/VCR cell were inoculated into nude mice subcutaneously. The mice were randomly divided into four groups: group A received normal saline, group B received DNR, group C received MNPs-Fe3O4, and group D received DNR-loaded MNPs-Fe3O4. For K562-n/VCR tumor, the weight was markedly lower in group D than that in groups A, B, and C. The transcriptions of Mdr-1 and Bcl-2 gene were significantly lower in group D than those in groups A, B, and C. The expression of Bcl-2 was lower in group D than those in groups A, B, and C, but there was no difference in the expression of P-glycoprotein. The transcriptions and expressions of Bax and caspase-3 in group D were increased significantly when compared with groups A, B, and C. In conclusion, DNR-loaded MNPs-Fe3O4 can overcome MDR in vivo.Keywords: multidrug-resistance reversal, leukemia, magnetic nanoparticles of Fe3O4, in vivo

  19. Reduced-temperature ordering of FePt nanoparticle assembled films by Fe30Pt70/Fe3O4 core/shell structure

    Institute of Scientific and Technical Information of China (English)

    He Shu-Li; Peng Yin; Liu Li-Li; Jiang Hong-Wei; Liu Li-Feng; Zheng Wu; Wang Ai-Ling

    2007-01-01

    In this paper, Fe3oPt70/Fe3O4 core/shell nanoparticles were synthesized by chemical routine and the layered polycthylenimine (PEI)-Fe30Pt70/Fe3O4 structure was constructed by molecule-mediated self-assembly technique. The dimension of core/shell structured nanoparticles was that of 4nm core and 2 nm shell. After annealing under a flow of forming gas (50%Ar2%%30%H2) for 1h at or above 400℃, the iron oxide shell was reduced to Fe and diffused to Pt-rich core, which leaded to the formation of L10 phase FePt at low temperature. The x-ray diffraction results and magnetic properties measurement showed that the chemical ordering temperature of Fe30Pt70/Fe3O4 core/shell nanoparticles assembly can be reduced to as low as 400℃. The sample annealed at 400℃ showed the coercivity of 4 KOe with the applied field of 1.5T. The core/shell structure was suggested to be an effective way to reduce the ordering temperature obviously.

  20. Magnetic Fe3O4@TiO2 Nanoparticles-based Test Strip Immunosensing Device for Rapid Detection of Phosphorylated Butyrylcholinesterase

    Energy Technology Data Exchange (ETDEWEB)

    Ge, Xiaoxiao; Zhang, Weiying; Lin, Yuehe; Du, Dan

    2013-12-15

    An integrated magnetic nanoparticles-based test-strip immunosensing device was developed for rapid and sensitive quantification of phosphorylated butyrylcholinesterase (BChE), the biomarker of exposure to organophosphous pesticides (OP), in human plasma. In order to overcome the difficulty in scarce availability of OP-specific antibody, here magnetic Fe3O4@TiO2 nanoparticles were used and adsorbed on the test strip through a small magnet inserted in the device to capture target OP-BChE through selective binding between TiO2 and OP moiety. Further recognition was completed by horseradish peroxidase (HRP) and anti-BChE antibody (Ab) co-immobilized gold nanoparticles (GNPs). Their strong affinities among Fe3O4@TiO2, OP-BChE and HRP/Ab-GNPs were characterized by quartz crystal microbalance (QCM), surface plasmon resonance (SPR) and square wave voltammetry (SWV) measurements. After cutting off from test strip, the resulted immunocomplex (HRP/Ab-GNPs/OP-BChE/Fe3O4@TiO2) was measured by SWV using a screen printed electrode under the test zone. Greatly enhanced sensitivity was achieved by introduction of GNPs to link enzyme and antibody at high ratio, which amplifies electrocatalytic signal significantly. Moreover, the use of test strip for fast immunoreactions reduces analytical time remarkably. Coupling with a portable electrochemical detector, the integrated device with advanced nanotechnology displays great promise for sensitive, rapid and in-filed on-site evaluation of OP poisoning.

  1. Convenient Preparation and Characterization of Surface Carboxyl-functioned Fe3O4 Magnetic Nanoparticles%表面羧基化Fe3O4磁性纳米粒子的快捷制备及表征

    Institute of Scientific and Technical Information of China (English)

    苏鹏飞; 陈国; 赵珺

    2011-01-01

    Hydrophilic magnetic nanoparticles have been widely applied in biological sciences. In this work, we proposed a convenient method to synthesize surface carboxylic magnetic nanoparticles. Firstly, hydrophobic magnetic nanoparticles coated with oleic acid were prepared from ferric chloride and ferrous chloride by co-precipitation method, with oleic acid as surfactant. Then the C =C bond of oleic acid coated on the surface of particles was oxidized into -COOH by KMnO4 solution in situ, thereby hydrophobic magnetic nanoparticles functioned by monolayer carboxylic groups were obtained. The magnetic nanoparticles were characterized by transmission electron microscopy(TEM) , X-ray diffraction ( XRD ) , Fourier transform infrared ( FTIR) , ther-mogravimetric analysis( TGA) , vibrating sample magnetometry ( VSM) and Zeta potential analyzer and so on. The results showed that magnetic nanoparticles surface was successfully carboxyl-functioned. The average diameter and the saturation magnetization of the nanoparticles were about 9 nm and 64. 5 A · M2/kg, respectively. The remnant magnetization and coercivity of the nanoparticles were nearly to be 0, which demonstrated it was classic superparamagnetic. The carboxyl-functioned magnetic nanoparticles could be dispersed into water to form ferrofluid, which were stable for more than 42 d without precipitation at pH values of 7-10.%提出了一种快速对磁性纳米粒子表面羧基化的方法.以氯化铁和氯化亚铁为原料,油酸为表面活性剂,通过共沉淀法制得油酸包覆的亲油性Fe3O4磁性纳米粒子,然后用高锰酸钾进行原位氧化,将覆盖在粒子表面油酸中的C=C键氧化成-COOH,从而得到单层羧基功能化的亲水性磁性纳米粒子.利用透射电子显微镜(TEM),X射线衍射仪(XRD)、傅里叶变换红外光谱仪(FTIR)、热重分析仪(TGA)、振动样品磁强计( VSM)和Zeta电位分析仪等对其进行了表征.结果表明,磁性纳米粒子的表面被成功羧基

  2. A Novel Nanofilm Sensor Based on Poly-(Alizarin Red)/Fe3O4 Magnetic Nanoparticles-Multiwalled Carbon Nanotubes Composite Material for Determination of Nitrite.

    Science.gov (United States)

    Qu, Jianying; Dong, Ying; Yong, Wang; Lou, Tongfang; Du, Xueping; Qu, Jianhang

    2016-03-01

    Fe3O4 magnetic nanoparticles were synthesized by chemical co-precipitation with sodium citrate as surfactant and were characterized by FT-IR spectrometer, X-ray diffraction and transmission electron microscopy. A novel nitrite sensor was fabricated by electropolymerization of alizarin red on the surface of glassy carbon electrode modified with Fe3O4-multiwalled carbon nanotubes composite nanofilm. Under the optimal experimental conditions, it was showed that the proposed sensor exhibited good electrocatalytic activity to the oxidation of nitrite, and the peak current increased linearly with the nitrite concentration from 9.64 x 10(-6) mol x L(-1) to 1.30 x 10(-3) mol x L(-1) (R = 0.9976) with a detection limit of 1.19 x 10(-6) mol x L(-1) (S/N = 3). This sensor showed excellent sensitivity, wide linear range, stability and repeatability for nitrite determination with potential applications.

  3. Design and construction of polymerized-chitosan coated Fe3O4 magnetic nanoparticles and its application for hydrophobic drug delivery

    International Nuclear Information System (INIS)

    In this study, a novel hydrogel, chitosan (CS) crosslinked carboxymethyl-β-cyclodextrin (CM-β-CD) polymer modified Fe3O4 magnetic nanoparticles was synthesized for delivering hydrophobic anticancer drug 5-fluorouracil (CS-CDpoly-MNPs). Carboxymethyl-β-cyclodextrin being grafted on the Fe3O4 nanoparticles (CDpoly-MNPs) contributed to an enhancement of adsorption capacities because of the inclusion abilities of its hydrophobic cavity with insoluble anticancer drugs through host–guest interactions. Experimental results indicated that the amounts of crosslinking agent and bonding times played a crucial role in determining morphology features of the hybrid nanocarriers. The nanocarriers exhibited a high loading efficiency (44.7 ± 1.8%) with a high saturation magnetization of 43.8 emu/g. UV–Vis spectroscopy results showed that anticancer drug 5-fluorouracil (5-Fu) could be successfully included into the cavities of the covalently linked CDpoly-MNPs. Moreover, the free carboxymethyl groups could enhance the bonding interactions between the covalently linked CDpoly-MNPs and anticancer drugs. In vitro release studies revealed that the release behaviors of CS-CDpoly-MNPs carriers were pH dependent and demonstrated a swelling and diffusion controlled release. A lower pH value led to swelling effect and electrostatic repulsion contributing to the protonation amine impact of NH3+, and thus resulted in a higher release rate of 5-Fu. The mechanism of 5-Fu encapsulated into the magnetic chitosan nanoparticles was tentatively proposed. - Graphical abstract: A novel nanocarrier, chitosan-coated magnetic drug carrier nanoparticle (CS-CDpoly-MNPs) is fabricated for the delivery of insoluble anticancer drug by grafting CM-β-CD onto the magnetite surface. The grafting of CM-dextrins onto the surface of Fe3O4 nanocrystal clusters can markedly increase the loading capacity of 5-Fu by virtue of CM-dextrins/5-Fu inclusion complex formation. The release of 5-Fu from nanocomposite

  4. Facile One-pot Transformation of Iron Oxides from Fe2O3 Nanoparticles to Nanostructured Fe3O4@C Core-Shell Composites via Combustion Waves.

    Science.gov (United States)

    Shin, Jungho; Lee, Kang Yeol; Yeo, Taehan; Choi, Wonjoon

    2016-01-01

    The development of a low-cost, fast, and large-scale process for the synthesis and manipulation of nanostructured metal oxides is essential for incorporating materials with diverse practical applications. Herein, we present a facile one-pot synthesis method using combustion waves that simultaneously achieves fast reduction and direct formation of carbon coating layers on metal oxide nanostructures. Hybrid composites of Fe2O3 nanoparticles and nitrocellulose on the cm scale were fabricated by a wet impregnation process. We demonstrated that self-propagating combustion waves along interfacial boundaries between the surface of the metal oxide and the chemical fuels enabled the release of oxygen from Fe2O3. This accelerated reaction directly transformed Fe2O3 into Fe3O4 nanostructures. The distinctive color change from reddish-brown Fe2O3 to dark-gray Fe3O4 confirmed the transition of oxidation states and the change in the fundamental properties of the material. Furthermore, it simultaneously formed carbon layers of 5-20 nm thickness coating the surfaces of the resulting Fe3O4 nanoparticles, which may aid in maintaining the nanostructures and improving the conductivity of the composites. This newly developed use of combustion waves in hybridized nanostructures may permit the precise manipulation of the chemical compositions of other metal oxide nanostructures, as well as the formation of organic/inorganic hybrid nanostructures. PMID:26902260

  5. Synthesis and Properties of Fe3O4-Activated Carbon Magnetic Nanoparticles for Removal of Aniline from Aqueous Solution: Equilibrium, Kinetic and Thermodynamic Studies

    Directory of Open Access Journals (Sweden)

    Babak Kakavandi

    2013-02-01

    Full Text Available In this study, powder activated carbon (PAC and magnetic nanoparticles of iron (III oxide were used for synthesis of Fe3O4-activated carbon magnetic nanoparticles (AC-Fe3O4 MNPs as an adsorbent for the removal of aniline. The characteristics of adsorbent were evaluated by SEM, TEM, XRD and BET. Also, the impact of different parameters such as pH, contact time, adsorbent dosage, aniline initials concentration and solution temperature were studied. The experimental data investigated by Langmuir and Freundlich adsorption isotherms and two models kinetically of pseudo first-order and pseudo second-order. The results indicated that the adsorption followed Langmuir and pseudo second-order models with correlation r2 > 0.98 and r2 > 0.99, respectively. The equilibrium time was obtained after 5 h. According to Langmuir model, the maximum adsorption capacity was 90.91 mg/g at pH = 6, and 20°C. The thermodynamic parameters indicated that adsorption of aniline on magnetic activated carbon was exothermic and spontaneous. This synthesized AC-Fe3O4 MNPs due to have advantages such as easy and rapid separation from solution could be applied as an adsorbent effective for removal of pollutants such as aniline from water and wastewater

  6. Facile One-pot Transformation of Iron Oxides from Fe2O3 Nanoparticles to Nanostructured Fe3O4@C Core-Shell Composites via Combustion Waves

    Science.gov (United States)

    Shin, Jungho; Lee, Kang Yeol; Yeo, Taehan; Choi, Wonjoon

    2016-01-01

    The development of a low-cost, fast, and large-scale process for the synthesis and manipulation of nanostructured metal oxides is essential for incorporating materials with diverse practical applications. Herein, we present a facile one-pot synthesis method using combustion waves that simultaneously achieves fast reduction and direct formation of carbon coating layers on metal oxide nanostructures. Hybrid composites of Fe2O3 nanoparticles and nitrocellulose on the cm scale were fabricated by a wet impregnation process. We demonstrated that self-propagating combustion waves along interfacial boundaries between the surface of the metal oxide and the chemical fuels enabled the release of oxygen from Fe2O3. This accelerated reaction directly transformed Fe2O3 into Fe3O4 nanostructures. The distinctive color change from reddish-brown Fe2O3 to dark-gray Fe3O4 confirmed the transition of oxidation states and the change in the fundamental properties of the material. Furthermore, it simultaneously formed carbon layers of 5–20 nm thickness coating the surfaces of the resulting Fe3O4 nanoparticles, which may aid in maintaining the nanostructures and improving the conductivity of the composites. This newly developed use of combustion waves in hybridized nanostructures may permit the precise manipulation of the chemical compositions of other metal oxide nanostructures, as well as the formation of organic/inorganic hybrid nanostructures. PMID:26902260

  7. 纳米Fe3O4的居里温度和粒径的依赖性%Dependence of the Curie temperature on the diameter of Fe3O4 nanoparticles

    Institute of Scientific and Technical Information of China (English)

    拜山·沙德克; 彭登峰

    2008-01-01

    超细Fe3O4粒子(5~50nm)用化学共沉淀法制备,粒子的半径由FeSO4·7H2O和NaNO2的摩尔比来控制.通过磁性测试发现,居里温度Tc随粒径变小而降低,并且还发现,在高温下由于超细Fe3O4粒子团簇长大,对应Tc明显升高.粒子的居里温度Tc值由公式M~(1-T/Tc)β确定.

  8. 双微乳液法制备纳米磁性Fe3O4粉体的研究%Study on preparation of magnetic Fe3O4 nano-particle with double micro-emulsion

    Institute of Scientific and Technical Information of China (English)

    宋丽贤; 卢忠远; 廖其龙

    2005-01-01

    现代诊断学的发展使得纳米级超顺磁性的Fe3O4粒子在医学领域具有重要应用价值.本实验采用双微乳液法制备纳米磁性Fe3O4粉体.从反应物浓度、表面活性剂用量、油相用量及反应温度等方面讨论对产物粒径的影响,通过正交试验确定了制备纳米Fe3O4粉体的最佳工艺条件.对获得的粉体采用激光散射法粒度测试、XRD物相分析和粒径计算、原子力显微镜(AFM)和透射电子显微镜(TEM)形貌观察、振动样品磁强计磁性测定等进行表征,结果表明制备的Fe3O4粉体平均粒径约为24nm、粒度分布均匀、分布带较窄且产物纯度高;该粉体具有超顺磁性,饱和磁化强度在66A·m2/kg左右.

  9. PEI包覆磁性Fe3O4纳米颗粒的制备及性能研究%Synthesis and Property Analysis of PEI-coated Fe3O4 Nanoparticles

    Institute of Scientific and Technical Information of China (English)

    李成魁; 严彪; 杜春风; 赵慎强

    2010-01-01

    由于PEI/Fe3O4磁流体具有良好的生物兼容性,因而被广泛应用于生物医药领域.本实验用共沉淀法制备出磁性Fe3O4纳米颗粒,通过一次包覆改性法将PEI(聚乙烯亚胺)包覆在磁性Fe3O4纳米颗粒上.利用X-射线衍射仪(XRD)、透射电子显微镜(TEM)、红外光谱仪(FTIR)、振动样品磁强计(VSM)、热重分析仪(TG)等方法对其进行了表征.结果表明,实验制备出颗粒度为10nm左右的颗粒,PEI较好的吸附在其表面,吸附率为33.6%,颗粒度饱和磁化强度为58.05 emu/g,包覆后有所降低,但较好保持着原有磁性.

  10. Fe3 O4 Nanoparticles Synthesis With Folic Acid-coupling and Marked Tumor Experimental Research%以叶酸偶联纳米 Fe3 O4颗粒的合成和标记肿瘤实验研究

    Institute of Scientific and Technical Information of China (English)

    胡丰; 唐宁宁; 刘灿; 唐园园; 王少华; 尹朝奇; 周春姣; 周建大; 曾蔚

    2014-01-01

    目的:研究叶酸偶联的超顺磁Fe3 O4纳米颗粒对活体肝癌标记效果和MRI成像功能。方法:以铁盐、十二烷基苯磺酸和3-氨基丙基3-乙氧基硅烷为原料,通过共沉淀法合成了APTES修饰的超顺磁Fe3 O4纳米颗粒,通过酰胺化法合成了叶酸偶联的超顺磁Fe3 O4纳米颗粒,以X射线衍射仪、透射电镜、红外光谱仪、振动样品磁强计、动态光散射仪对合成材料进行表征,采用SRB法对叶酸偶联的超顺磁Fe3 O4纳米颗粒细胞进行安全性检测,同时建立活体瘤鼠动物模型,对其在叶酸偶联的超顺磁Fe3 O4纳米颗粒标记前后进行MRI成像对比检测,每个肿瘤组织块各取2套切片,分别行苏木素-伊红染色和普鲁士蓝染色,观察肿瘤组织光镜下形态及组织内含Fe情况。结果:所制备的叶酸偶联的Fe3 O4纳米颗粒为立方相的Fe3 O4,粒径约8 nm左右,水合直径25.7 nm,呈近似球形,表面分布有羧基等功能基团,呈超顺磁特性,饱和磁化强度为51 emu/g Fe。叶酸偶联的超顺磁Fe3 O4纳米颗粒对人皮肤成纤维细胞(HSF)的生长与生理盐水对照组的影响一样,无明显抑制细胞生长的表现。同时,磁共振成像和染色结果均显示肿瘤的存在。结论:叶酸偶联的超顺磁Fe3 O4纳米颗粒,不仅细胞毒性小,而且因其表面的叶酸与叶酸受体之间的高强结合力。同时,它能通过这种结合作用被高效介导进入肿瘤细胞内,增强MRI成像中肿瘤组织与周围正常组织的对比度,有利于肿瘤细胞的标记、示踪和靶向检测,是一种很有应用前景的肿瘤细胞靶向检测物质。%Objective:To research the labeling effect of folate-conjugated Fe3 O4 nanoparticles on hepatocellular carci-noma in vivo and the function of MRI imaging.Methods:ATPES-modified Fe3 O4 nanoparticles were synthesized through co-precipitation action using iron salt,sodium dodecyl

  11. Fast assembling microarrays of superparamagnetic Fe3O4@Au nanoparticle clusters as reproducible substrates for surface-enhanced Raman scattering

    Science.gov (United States)

    Ye, Min; Wei, Zewen; Hu, Fei; Wang, Jianxin; Ge, Guanglu; Hu, Zhiyuan; Shao, Mingwang; Lee, Shuit-Tong; Liu, Jian

    2015-08-01

    It is currently a very active research area to develop new types of substrates which integrate various nanomaterials for surface-enhanced Raman scattering (SERS) techniques. Here we report a unique approach to prepare SERS substrates with reproducible performance. It features silicon mold-assisted magnetic assembling of superparamagnetic Fe3O4@Au nanoparticle clusters (NCs) into arrayed microstructures on a wafer scale. This approach enables the fabrication of both silicon-based and hydrogel-based substrates in a sequential manner. We have demonstrated that strong SERS signals can be harvested from these substrates due to an efficient coupling effect between Fe3O4@Au NCs, with enhancement factors >106. These substrates have been confirmed to provide reproducible SERS signals, with low variations in different locations or batches of samples. We investigate the spatial distributions of electromagnetic field enhancement around Fe3O4@Au NCs assemblies using finite-difference-time-domain (FDTD) simulations. The procedure to prepare the substrates is straightforward and fast. The silicon mold can be easily cleaned out and refilled with Fe3O4@Au NCs assisted by a magnet, therefore being re-useable for many cycles. Our approach has integrated microarray technologies and provided a platform for thousands of independently addressable SERS detection, in order to meet the requirements of a rapid, robust, and high throughput performance.It is currently a very active research area to develop new types of substrates which integrate various nanomaterials for surface-enhanced Raman scattering (SERS) techniques. Here we report a unique approach to prepare SERS substrates with reproducible performance. It features silicon mold-assisted magnetic assembling of superparamagnetic Fe3O4@Au nanoparticle clusters (NCs) into arrayed microstructures on a wafer scale. This approach enables the fabrication of both silicon-based and hydrogel-based substrates in a sequential manner. We have

  12. Magnetic Fe3O4/Ag Hybrid Nanoparticles as Surface-Enhanced Raman Scattering Substrate for Trace Analysis of Furazolidone in Fish Feeds

    Directory of Open Access Journals (Sweden)

    Wansong Yu

    2014-01-01

    Full Text Available Nanoparticles (NPs composed of ferromagnetic and noble metal materials show dual functions of magnetic activity and local surface plasmon response and have great potential as substrates for surface-enhanced Raman scattering (SERS in trace analysis. Easy-to-prepare superparamagnetic Fe3O4/Ag hybrid NPs were synthesized and optimized by adjusting the ratio of silver particles aggregated with APTMS-modified Fe3O4 NPs. The hybrid NPs were assembled under an external magnetic field before being used as substrate for SERS analysis. The SERS spectral features of furazolidone standard solution were clearly identified at concentrations as low as 40 ng mL−1, and furazolidone in fish feeds could be detected at 500 ng g−1. The results indicated that the Fe3O4/Ag hybrid NPs as SERS substrates had a great potential for detection of trace amount of furazolidone and other prohibited or restricted antibiotics in the animal and fish feeds.

  13. Highly Sensitive Electrochemical Biosensor for Evaluation of Oxidative Stress Based on the Nanointerface of Graphene Nanocomposites Blended with Gold, Fe3O4, and Platinum Nanoparticles.

    Science.gov (United States)

    Wang, Le; Zhang, Yuanyuan; Cheng, Chuansheng; Liu, Xiaoli; Jiang, Hui; Wang, Xuemei

    2015-08-26

    High levels of H2O2 pertain to high oxidative stress and are associated with cancer, autoimmune, and neurodegenerative disease, and other related diseases. In this study, a sensitive H2O2 biosensor for evaluation of oxidative stress was fabricated on the basis of the reduced graphene oxide (RGO) nanocomposites decorated with Au, Fe3O4, and Pt nanoparticles (RGO/AuFe3O4/Pt) modified glassy carbon electrode (GCE) and used to detect the released H2O2 from cancer cells and assess the oxidative stress elicited from H2O2 in living cells. Electrochemical behavior of RGO/AuFe3O4/Pt nanocomposites exhibits excellent catalytic activity toward the relevant reduction with high selection and sensitivity, low overpotential of 0 V, low detection limit of ∼0.1 μM, large linear range from 0.5 μM to 11.5 mM, and outstanding reproducibility. The as-prepared biosensor was applied in the measurement of efflux of H2O2 from living cells including healthy normal cells and tumor cells under the external stimulation. The results display that this new nanocomposites-based biosensor is a promising candidate of nonenzymatic H2O2 sensor which has the possibility of application in clinical diagnostics to assess oxidative stress of different kinds of living cells.

  14. Synthesis, characterization and wound healing imitation of Fe3O4 magnetic nanoparticle grafted by natural products

    Science.gov (United States)

    Pala, Sravan Kumar

    This research focused on the study of the core-shelled magnetic nanomaterials derived from a colloidal chemistry. The goals are four-fold: (1) synthesis of Fe3O4MNMs using colloidal chemistry. The Fe 3O4 MNMs were then grafted with extracts derived from natural products, namely Olecraceavar italica (broccoli), Boletus edulis (mushroom)and Solanum lycopersicum (tomato);(2)characterization of natural products by chromatography and mass spectrometry;(3) characterization of MNMs to determine their crystallinity, morphological and elemental composition by the state-of-the-art instruments; and (4) biological evaluation using Gram-negative and Gram-positive bacteria. The approach provides advantages to precisely control the composition and homogeneity. The second advantage of the colloidal chemistry is its user friendliness and feasibility. Due to the nature of the natural products, the compatibility of MNM is anticipated to be enhanced.In this chapter, the nanomaterials will be discussed from four perspectives,§1.1 Nanotechnology (§1.1), §1.2 Synthesis of nanomaterials; §1.3 The natural product extract,; §1.4 Characterization of nanomaterials; and §1.5Biological application of nanomaterials.Fig. 1 summarized the overarching goals of this study.

  15. 功能化磁性Fe3O4纳米粒子用于含Cu2+废水的净化%Purification of waste water containing Cu2+ using functionalized magnetic Fe3O4 nanoparticles

    Institute of Scientific and Technical Information of China (English)

    刘安康; 柳越; 何涛; 李雪梅

    2012-01-01

    Superparamagnetic iron oxide nanoparticle ( SPION) was prepared by co-precipitation. Func-tionalized magnetic ( Fe3 O4 -NH2 ) was obtained by silanization of the SPION with (3-aminopropyl) trie-thoxysilane (APTES). Both Fe3O4 and Fe3O4-NH2 nanoparticles were tested for removal of Cu2+ from waste water,and effects of pH and initial concentration(ρ) of Cu2+ solution on adsorption efficiency were investigated. The results showed that the adsorption capacity increased with pH and ρ of the solution and the capacity reached the maximum when pH was 5. Adsorption equilibrium was obtained on a concentration of 5 g/L, which were 12. 49 mg/g and 103. 41 mg/g for Fe3O4 and Fe3O4-NH2.%采用共沉淀法制备超顺磁性Fe3O4纳米粒子(SPION),并通过硅烷化在SPION粒子表面引入3-氨丙基三乙氧基硅烷(APTES),制得氨基化磁性纳米粒子(Fe3O4-NH2),比较改性前后SPION对于重金属离子Cu2+的吸附,分别考察吸附溶液的pH和Cu2+初始质量浓度(ρ)对吸附效果的影响.结果表明:吸附量均随溶液pH和ρ的升高而增加,在pH为5时达到最大吸附量,ρ为5 g/L时均达到吸附平衡,Fe3O4Fe3O4-NH2吸附量分别为12.49和103.41 mg/g.

  16. Preparation and characterization of highly water-soluble magnetic Fe3O4 nanoparticles via surface double-layered self-assembly method of sodium alpha-olefin sulfonate

    International Nuclear Information System (INIS)

    A kind of double-layered self-assembly sodium alpha-olefin sulfonate (AOS) capped Fe3O4 magnetic nanoparticles (Fe3O4-AOS-MN) with highly water-solubility was prepared by a wet co-precipitation method with a pH of 4.8. The resulting Fe3O4-AOS-MN could be dispersed into water to form stable magnetic fluid without other treatments. The result of X-ray diffraction (XRD) indicated that the Fe3O4-AOS-MN maintained original crystalline structure and exhibited a diameter of about 7.5 nm. The iron oxide phase of nanoparticles determined by Raman spectroscopy is Fe3O4. Transmission electron microscopy (TEM) analysis confirmed that the Fe3O4-AOS-MN with spherical morphology were uniformly dispersed in water. FT-IR spectroscopy (FT-IR) and thermo-gravimetric analysis (TGA) verified the successful preparation of Fe3O4-AOS-MN capped with double-layered self-assembled AOS. The corresponding capacities of monolayer chemical absorption and the second-layer self-assembly absorption were respectively 4.07 and 14.71 wt% of Fe3O4-MN, which were much lower than those of other surfactants. Vibrating sample magnetometer (VSM) test result showed Fe3O4-AOS-MN possessed superparamagnetic behavior with the saturation magnetization value of about 44.45 emu/g. The blocking temperature TB of Fe3O4-AOS-MN capped with double-layered AOS is 170 K. - Highlights: • Double-layered self-assembly sodium alpha-olefin sulfonate (AOS) capped Fe3O4 magnetic nanoparticles are prepared by a wet co-precipitation method. • Double-layered Fe3O4-AOS-MN exhibits highly water-solubility. • The iron oxide phase is determined by Raman spectroscopy. • Fe3O4-AOS-MN capped with double-layered AOS possesses super-paramagnetic behavior. • The blocking temperature TB of Fe3O4-AOS-MN capped with double-layered AOS is 170 K

  17. Fe3O4磁性纳米颗粒外包腐植酸用于有效去除水中重金属%Coating Fe3O4 Magnetic Nanoparticles with Humic Acid for High Efifcient Removal of Heavy Metals in Water

    Institute of Scientific and Technical Information of China (English)

    Liu Jingfu; Zhao Zongshan; Jiang Guibin; 任翠领(译)

    2015-01-01

    本研究合成了腐植酸(HA)包裹的Fe3O4纳米颗粒(Fe3O4/HA)并将其用于去除水中的重金属离子,包括Hg(I )、Pb(I )、Cd(I )和Cu(I )。以价格低廉、环境友好的铁盐和腐植酸为原料,通过共沉淀方法制备Fe3O4/HA。TOC和XPS的分析结果表明所制备的Fe3O4/HA中约含有11%(w/w)的叶酸,它是含O和N-官能团丰富的组分。TEM成像和激光颗粒尺寸分析证实所制备的Fe3O4/HA(Fe3O4内核约为10 nm)在水溶液中团聚并形成了平均水和半径约为140 nm的聚集体,饱和磁化强度为79.6 emu/g,这种Fe3O4/HA材料在低磁场梯度下几分钟内就可以从水溶液中分离。F e3O4/H A对重金属离子的吸附在15分钟内就可以达到平衡,其吸附行为符合朗格缪尔吸附模型,且最大吸附容量在46.3~97.7 mg/g范围内。制备的Fe3O4/HA在自来水、天然水、0.1 M HCl和2 M NaOH的酸/碱溶液中都很稳定,Fe(≤3.7%)和HA(≤5.3%)的泄漏率很低。在最优条件下,Fe3O4/HA纳米材料能够去除天然水和自来水中超过99%的Hg(I )和Pb(I )以及超过95%的Cu(I )和Cd(I )。Fe3O4/HA吸附的重金属离子泄露回水溶液的量几乎可以忽略。%Humic acid (HA) coated Fe3O4 nanoparticles (Fe3O4/HA) were developed for the removal of toxic Hg(II), Pb(II), Cd(II), and Cu(II) from water. Fe3O4/HA were prepared by a coprecipitation procedure with cheap and environ-mentally friendly iron salts and HA. TOC and XPS analysis showed the as-prepared Fe3O4/HA contains~11%(w/w) of HA which are fractions abundant in O and N-based functional groups. TEM images and laser particle size analysis re-vealed the Fe3O4/HA (with~10 nm Fe3O4 cores) aggregated in aqueous suspensions to form aggregates with an average hydrodynamic size of~140 nm. With a saturation magnetization of 79.6 emu/g, the Fe3O4/HA can be simply recovered from water with magnetic separations at low magnetic ifeld gradients within a few minutes. Sorption of the heavy met-als to

  18. 超小型Fe3O4/Au纳米复合微粒的制备与表征%Preparation and character of ultrasmall Fe3O4/Au nanoparticles

    Institute of Scientific and Technical Information of China (English)

    刘祖黎; 彭莉; 姚凯伦; 卢强华; 汪汉斌

    2005-01-01

    用反向微乳液法成功制备了超小型Fe3O4/Au磁性纳米复合微粒,并利用3-巯基丙酸将复合微粒直接从微乳液分离到有机溶剂中.用UV-Vis、VSM和TEM对产物进行了鉴定与表征,结果表明复合微粒分散良好,平均粒径为6.7nm,饱和磁化强度为9.7A·m2/kg.

  19. 共沉淀制备不同粒径Fe3O4纳米颗粒及磁性能的研究%Synthesis of Fe3O4 nanoparticles with various sizes and magnetic properties by coprecipitation

    Institute of Scientific and Technical Information of China (English)

    邵晓萍; 代波; 马拥军

    2011-01-01

    Nanoparticles of Fe3O4 with various sizes were synthesized from FeCl3 · 6H2O, FeCl2 · 4H2O and NaOH without use of surfactant by coprecipitation process. The phase structures, morphology, particle size and magnetic property of the products were characterized by X-ray diffraction (XRD), transmission electron microscopy (TEM) and vibrating sample magnetometer (VSM). It was found that the molar ratio of ferrous to ferric played an important role in the formation Fe3O4 nanoparticles. The mean diameter and magnetic property of Fe3O4 nanoparticles could be controlled by adjusting this ratio. The mean diameter of Fe3O4 nanoparticles swelled from about 10 to 20nm with the molar ratio of ferrous to ferric ferrous ions from 1: 2 to 6: 1. The saturation magnetization and the coercivity also increased correspondingly.%以氯化铁(FeCl3·6H2O)和氯化亚铁(FeCl2·4H2O)为原料,氢氧化钠(NaOH)为沉淀剂,在无表面活性剂作用下共沉淀制备出了不同粒径的Fe3O4纳米颗粒.采用X射线衍射(XRD)、透射电子显微镜(TEM)和振动样品磁强计(VSM)对产物的晶体结构、形貌、粒径及磁性能进行了表征.实验结果表明,n(Fe2+):n(Fe3+)摩尔比对纳米Fe3O4粒径有重要的影响.在保持铁离子总浓度恒定的情况下,通过调节反应体系中n(Fe2+):n(Fe3+)比例可以有效调控纳米Fe3O4的粒径及磁性能.n(Fe2+):n(Fe3+)从1:2增大到6:1时,Fe3O4的平均粒径从10nm增加到20nm,饱和磁化强度和矫顽力也随之增大.

  20. Aligned Structures of Fe3O4 Nanoparticles in a Curable Polymer Carrier Induced by a Magnetic Field

    Institute of Scientific and Technical Information of China (English)

    FANG Wen-Xiao; HE Zhen-Hui; XU Xue-Qing; SHEN Hui

    2005-01-01

    @@ To understand the interaction in dipolar systems, it is necessary to investigate the structures formed by the interacting particles. We introduce a polymer acrylic resin carrier to fix the structures in the magnetic fluid(Fe3O4). An aligned structure is investigated, which is formed under a magnetic field, and fixed in the cured acrylic resin film by evaporating the solvent at room temperature. The aligned structure is confirmed with the help of optical microscopy and optical diffraction for the cured film. Furthermore, we find substructures by using a scanning electronic microscope. Based on the curable and observable structures, a platform can be developed for investigating the aligned structures and configurations dominant by dipolar interaction. This is also helpful for the development of magnetic devices with orderly aligned structures.

  1. Preparation and characterization of highly water-soluble magnetic Fe3O4 nanoparticles via surface double-layered self-assembly method of sodium alpha-olefin sulfonate

    Science.gov (United States)

    Li, Honghong; Qin, Li; Feng, Ying; Hu, Lihua; Zhou, Chunhua

    2015-06-01

    A kind of double-layered self-assembly sodium alpha-olefin sulfonate (AOS) capped Fe3O4 magnetic nanoparticles (Fe3O4-AOS-MN) with highly water-solubility was prepared by a wet co-precipitation method with a pH of 4.8. The resulting Fe3O4-AOS-MN could be dispersed into water to form stable magnetic fluid without other treatments. The result of X-ray diffraction (XRD) indicated that the Fe3O4-AOS-MN maintained original crystalline structure and exhibited a diameter of about 7.5 nm. The iron oxide phase of nanoparticles determined by Raman spectroscopy is Fe3O4. Transmission electron microscopy (TEM) analysis confirmed that the Fe3O4-AOS-MN with spherical morphology were uniformly dispersed in water. FT-IR spectroscopy (FT-IR) and thermo-gravimetric analysis (TGA) verified the successful preparation of Fe3O4-AOS-MN capped with double-layered self-assembled AOS. The corresponding capacities of monolayer chemical absorption and the second-layer self-assembly absorption were respectively 4.07 and 14.71 wt% of Fe3O4-MN, which were much lower than those of other surfactants. Vibrating sample magnetometer (VSM) test result showed Fe3O4-AOS-MN possessed superparamagnetic behavior with the saturation magnetization value of about 44.45 emu/g. The blocking temperature TB of Fe3O4-AOS-MN capped with double-layered AOS is 170 K.

  2. Synthesis of Fe3O4 nanoparticles and magnetic properties by chemical reduction%化学还原法制备Fe3O4纳米颗粒及其性能研究

    Institute of Scientific and Technical Information of China (English)

    冯辉霞; 陈柏屹; 张德懿; 雒和明

    2013-01-01

    采用化学还原法制备得到了Fe3O4纳米颗粒,并用XRD对制备条件:分散剂种类、分散剂用量、煅烧温度、煅烧时间进行了研究.研究结果表明,当选用PEG(6000)做分散剂,PEG用量为50g/L,煅烧温度为700℃,煅烧时间为120min时,制备得到的Fe3O4纳米颗粒已经具有晶型完整的反尖晶石结构.将该样品做VSM分析,分析结果表明样品饱和磁化强度可达85A·m2/kg,并且矫顽力趋近于0,呈现出良好的顺磁性.

  3. 多元醇法制备纳米Fe3O4及其静磁性能的研究%Research on preparing Fe3O4 nanoparticles by polyol process and magnetic properties

    Institute of Scientific and Technical Information of China (English)

    刘飚; 官建国; 张清杰

    2006-01-01

    以氯化亚铁为前驱物,1,2-丙二醇为还原剂,采用多元醇法意外获得Fe3O4纳米粒子.通过X射线衍射分析标定了获得样品的物相为面心立方结构的Fe3O4,用透射电镜观察了样品的形貌,颗粒形貌为球形,大小为50~70nm,反应机理的研究表明,Fe2+发生了歧化反应,反应主要向氧化的方向进行.用振动样品磁强计表征了样品的静磁性能,测得的饱和磁化强度为74.30A·m2/kg,矫顽力仅为102.68A/m,粒子具有超顺磁性.

  4. Morphological, Thermal, and Magnetic Analysis of Ball-Milled γ-Fe2O3 and Fe3O4 Nanoparticles for Biomedical Application

    Science.gov (United States)

    Burnham, Philip; Papaefthymiou, Georgia C.; Viescas, Arthur; Li, Calvin; Dollahon, Norman

    2013-03-01

    Superparamagnetic iron oxide nanoparticles are promising agents for hyperthermia cancer treatment, because, when exposed to an alternating magnetic field, they impart heat to surrounding tissue. A comparison of γ-Fe2O3 and Fe3O4 nanoparticles for such application is presented. The particles were obtained via surfactant-assisted high energy ball-milling in a hexane/oleic acid carrier-fluid environment. Particles with diameters of 5 to 16 nm were prepared with mass ratios (oleic acid):(γ-Fe2O3) of 0:1, 1:5, 1:10 and 1:20, with milling times of 3, 6, 9, and 12 hours. TEM micrographs revealed spherical morphology and the effect of oleic acid shells. Optimal size distributions were obtained for high oleic acid contents. At room temperature, a reduced internal magnetic field ~480 kOe) was recorded via Mössbauer spectroscopy compared to bulk γ-Fe2O3 ~500 kOe), due to magnetic relaxation; Fe3O4 particles produced similar results. For the γ-Fe2O3 and Fe3O4 nanoparticles with 20% oleic acid by mass, comparative ZFC/FC magnetization (Happ = 200 Oe in temperature range from 2 to 400 K) and hysteresis loops (T = 2 K and 300 K up to Happ = 6 kOe) were obtained. Thermal transport characteristics were verified by Specific Absorption Rate (SAR) measurements using an AC magnetic field (f = 282 kHz). Differences and similarities in behavior will be discussed.

  5. Au Nanocage Functionalized with Ultra-small Fe3O4 Nanoparticles for Targeting T1–T2Dual MRI and CT Imaging of Tumor

    Science.gov (United States)

    Wang, Guannan; Gao, Wei; Zhang, Xuanjun; Mei, Xifan

    2016-06-01

    Diagnostic approaches based on multimodal imaging of clinical noninvasive imaging (eg. MRI/CT scanner) are highly developed in recent years for accurate selection of the therapeutic regimens in critical diseases. Therefore, it is highly demanded in the development of appropriate all-in-one multimodal contrast agents (MCAs) for the MRI/CT multimodal imaging. Here a novel ideal MCAs (F-AuNC@Fe3O4) were engineered by assemble Au nanocages (Au NC) and ultra-small iron oxide nanoparticles (Fe3O4) for simultaneous T1–T2dual MRI and CT contrast imaging. In this system, the Au nanocages offer facile thiol modification and strong X-ray attenuation property for CT imaging. The ultra-small Fe3O4 nanoparticles, as excellent contrast agent, is able to provide great enhanced signal of T1- and T2-weighted MRI (r1 = 6.263 mM‑1 s‑1, r2 = 28.117 mM‑1 s‑1) due to their ultra-refined size. After functionalization, the present MCAs nanoparticles exhibited small average size, low aggregation and excellent biocompatible. In vitro and In vivo studies revealed that the MCAs show long-term circulation time, renal clearance properties and outstanding capability of selective accumulation in tumor tissues for simultaneous CT imaging and T1- and T2-weighted MRI. Taken together, these results show that as-prepared MCAs are excellent candidates as MRI/CT multimodal imaging contrast agents.

  6. Removal of 4-Chlorophenol with Fe3O4 Nanoparticles/H2O2 System at High pH%高pH条件纳米Fe3O4催化H2O2分解去除水中4-氯酚

    Institute of Scientific and Technical Information of China (English)

    赵志伟; 师杰; 刘杰

    2015-01-01

    In this paper, removal of 4⁃chlorophenom in aqueous solution with Fe3O4/H2O2 system was carried out at pH 5 to evaluate the catalytic efficiency of Fe3O4 to H2O2. The results showed that the as⁃synthesized nanoparticles was pure Fe3O4 and had an inverse spinel structure. Fe3O4 had a high catalytic activity for the H2O2 decomposition to oxidize the 4⁃chlorophenol in aqueous solution. The removal efficiency of 4⁃chlorophenol can reached 96.8%after 180 min. When the dosage of Fe3O4 was lower than 2.0 g/L, the removal efficiency of 4⁃chlorophenol was directly proportional to the dosage of Fe3O4, but inversely to the dosage of Fe3O4 when it was higher than 2.0 g/L. With the increase of the H2O2 dosage, the removal rate of 4⁃chlorophenol first increased and then reduced gradually. The initial pH of solution had great effect on the 4⁃chlorophenol removal. The lower pH lead to the higher removal effi⁃ciency of 4⁃chlorophenol. The catalytic activity of Fe3O4 was still high after 5 repeated experiments.%为了克服非均相fenton催化反应中溶液初始pH过低的缺点,开展了pH=5时Fe3O4/H2O2体系催化氧化去除水中4-氯酚实验。试验结果表明:制备的铁氧化物为纯Fe3O4,具有反尖晶石八面体结构。纳米Fe3O4能够高效催化H2O2分解氧化水中的4-氯酚,反应180 min后4-氯酚的去除率达到96.8%。当催化剂投量小于2.0 g/L,4-氯酚的去除率随着催化剂投量的增加而升高;当催化剂投量大于2.0 g/L,去除率会随着投量的增加而降低。随着H2O2投量的增加,4-氯酚的去除率先升高后降低。溶液的初始pH对4-氯酚的去除影响较大,pH越低,去除速率和效率越高。重复使用5次以后,纳米Fe3O4仍然保持较高的催化活性。

  7. Manufacture of IRDye800CW-coupled Fe3O4 nanoparticles and their applications in cell labeling and in vivo imaging

    Directory of Open Access Journals (Sweden)

    Chen Zhongping

    2010-10-01

    Full Text Available Abstract Background In recent years, near-infrared fluorescence (NIRF-labeled iron nanoparticles have been synthesized and applied in a number of applications, including the labeling of human cells for monitoring the engraftment process, imaging tumors, sensoring the in vivo molecular environment surrounding nanoparticles and tracing their in vivo biodistribution. These studies demonstrate that NIRF-labeled iron nanoparticles provide an efficient probe for cell labeling. Furthermore, the in vivo imaging studies show excellent performance of the NIR fluorophores. However, there is a limited selection of NIRF-labeled iron nanoparticles with an optimal wavelength for imaging around 800 nm, where tissue autofluorescence is minimal. Therefore, it is necessary to develop additional alternative NIRF-labeled iron nanoparticles for application in this area. Results This study manufactured 12-nm DMSA-coated Fe3O4 nanoparticles labeled with a near-infrared fluorophore, IRDye800CW (excitation/emission, 774/789 nm, to investigate their applicability in cell labeling and in vivo imaging. The mouse macrophage RAW264.7 was labeled with IRDye800CW-labeled Fe3O4 nanoparticles at concentrations of 20, 30, 40, 50, 60, 80 and 100 μg/ml for 24 h. The results revealed that the cells were efficiently labeled by the nanoparticles, without any significant effect on cell viability. The nanoparticles were injected into the mouse via the tail vein, at dosages of 2 or 5 mg/kg body weight, and the mouse was discontinuously imaged for 24 h. The results demonstrated that the nanoparticles gradually accumulated in liver and kidney regions following injection, reaching maximum concentrations at 6 h post-injection, following which they were gradually removed from these regions. After tracing the nanoparticles throughout the body it was revealed that they mainly distributed in three organs, the liver, spleen and kidney. Real-time live-body imaging effectively reported the dynamic

  8. Design and construction of polymerized-chitosan coated Fe3O4 magnetic nanoparticles and its application for hydrophobic drug delivery.

    Science.gov (United States)

    Ding, Yongling; Shen, Shirley Z; Sun, Huadong; Sun, Kangning; Liu, Futian; Qi, Yushi; Yan, Jun

    2015-03-01

    In this study, a novel hydrogel, chitosan (CS) crosslinked carboxymethyl-β-cyclodextrin (CM-β-CD) polymer modified Fe3O4 magnetic nanoparticles was synthesized for delivering hydrophobic anticancer drug 5-fluorouracil (CS-CDpoly-MNPs). Carboxymethyl-β-cyclodextrin being grafted on the Fe3O4 nanoparticles (CDpoly-MNPs) contributed to an enhancement of adsorption capacities because of the inclusion abilities of its hydrophobic cavity with insoluble anticancer drugs through host-guest interactions. Experimental results indicated that the amounts of crosslinking agent and bonding times played a crucial role in determining morphology features of the hybrid nanocarriers. The nanocarriers exhibited a high loading efficiency (44.7±1.8%) with a high saturation magnetization of 43.8emu/g. UV-Vis spectroscopy results showed that anticancer drug 5-fluorouracil (5-Fu) could be successfully included into the cavities of the covalently linked CDpoly-MNPs. Moreover, the free carboxymethyl groups could enhance the bonding interactions between the covalently linked CDpoly-MNPs and anticancer drugs. In vitro release studies revealed that the release behaviors of CS-CDpoly-MNPs carriers were pH dependent and demonstrated a swelling and diffusion controlled release. A lower pH value led to swelling effect and electrostatic repulsion contributing to the protonation amine impact of NH3(+), and thus resulted in a higher release rate of 5-Fu. The mechanism of 5-Fu encapsulated into the magnetic chitosan nanoparticles was tentatively proposed.

  9. Optimization of Optical Absorption of Colloids of SiO2@Au and Fe3O4@Au Nanoparticles with Constraints

    Science.gov (United States)

    Xue, Xiaozheng; Sukhotskiy, Viktor; Furlani, Edward P.

    2016-01-01

    We study the optical response of monodisperse colloids of core-shell plasmonic nanoparticles and introduce a computational approach to optimize absorption for photothermal applications that require dilute colloids of non-interacting particles with a prescribed volume fraction. Since the volume fraction is held constant, the particle concentration is size-dependent. Optimization is achieved by comparing the absorption spectra of colloids as a function of particle size and structure. We demonstrate the approach via application to colloids of core-shell SiO2@Au and Fe3O4@Au nanoparticles with particle sizes that range from 5–100 nm and with the incident wavelength varying from 600–1200 nm. The absorption spectra are predicted using Mie theory and the analysis shows that there is a unique mix of parameters (core radius, shell thickness, wavelength) that maximize absorption, independent of the value of volume fraction. We show that lossy Fe3O4 cores produce a much broader absorption peak with much less sensitivity to variations in particle structure and wavelength than lossless SiO2 cores. This approach can be readily adapted to colloids of nanoparticles with arbitrary materials, shapes and structure using appropriate numerical methods to compute the absorption spectra. As such, it is useful for the rational design of colloids and process variables for a broad range of photothermal applications. PMID:27786279

  10. Conductive Fe3O4 Nanoparticles Accelerate Syntrophic Methane Production from Butyrate Oxidation in Two Different Lake Sediments

    Science.gov (United States)

    Zhang, Jianchao; Lu, Yahai

    2016-01-01

    Syntrophic methanogenesis is an essential link in the global carbon cycle and a key bioprocess for the disposal of organic waste and production of biogas. Recent studies suggest direct interspecies electron transfer (DIET) is involved in electron exchange in methanogenesis occurring in paddy soils, anaerobic digesters, and specific co-cultures with Geobacter. In this study, we evaluate the possible involvement of DIET in the syntrophic oxidation of butyrate in the enrichments from two lake sediments (an urban lake and a natural lake). The results showed that the production of CH4 was significantly accelerated in the presence of conductive nanoscale Fe3O4 or carbon nanotubes in the sediment enrichments. Observations made with fluorescence in situ hybridization and scanning electron microscope indicated that microbial aggregates were formed in the enrichments. It appeared that the average cell-to-cell distance in aggregates in nanomaterial-amended enrichments was larger than that in aggregates in the non-amended control. These results suggested that DIET-mediated syntrophic methanogenesis could occur in the lake sediments in the presence of conductive materials. Microbial community analysis of the enrichments revealed that the genera of Syntrophomonas, Sulfurospirillum, Methanosarcina, and Methanoregula were responsible for syntrophic oxidation of butyrate in lake sediment samples. The mechanism for the conductive-material-facilitated DIET in butyrate syntrophy deserves further investigation. PMID:27597850

  11. Conductive Fe3O4 Nanoparticles Accelerate Syntrophic Methane Production from Butyrate Oxidation in Two Different Lake Sediments.

    Science.gov (United States)

    Zhang, Jianchao; Lu, Yahai

    2016-01-01

    Syntrophic methanogenesis is an essential link in the global carbon cycle and a key bioprocess for the disposal of organic waste and production of biogas. Recent studies suggest direct interspecies electron transfer (DIET) is involved in electron exchange in methanogenesis occurring in paddy soils, anaerobic digesters, and specific co-cultures with Geobacter. In this study, we evaluate the possible involvement of DIET in the syntrophic oxidation of butyrate in the enrichments from two lake sediments (an urban lake and a natural lake). The results showed that the production of CH4 was significantly accelerated in the presence of conductive nanoscale Fe3O4 or carbon nanotubes in the sediment enrichments. Observations made with fluorescence in situ hybridization and scanning electron microscope indicated that microbial aggregates were formed in the enrichments. It appeared that the average cell-to-cell distance in aggregates in nanomaterial-amended enrichments was larger than that in aggregates in the non-amended control. These results suggested that DIET-mediated syntrophic methanogenesis could occur in the lake sediments in the presence of conductive materials. Microbial community analysis of the enrichments revealed that the genera of Syntrophomonas, Sulfurospirillum, Methanosarcina, and Methanoregula were responsible for syntrophic oxidation of butyrate in lake sediment samples. The mechanism for the conductive-material-facilitated DIET in butyrate syntrophy deserves further investigation. PMID:27597850

  12. Synthesis of superparamagnetic silica-coated magnetite nanoparticles for biomedical applications

    Science.gov (United States)

    Kaur, Navjot; Chudasama, Bhupendra

    2015-05-01

    Multifunctional superparamagnetic iron oxide nanoparticles (SPIONs) coated with silica are widely researched for biomedical applications such as magnetic resonance imaging, tissue repair, cell separation, hyperthermia, drug delivery, etc. In this article synthesis of magnetite (Fe3O4) nanoparticles and their coating with SiO2 is reported. Fe3O4 nanoparticles were synthesized by chemical co-precipitation and it was coated with silica by hydrolysis and condensation of tetraethylorthosilicate. XRD, FTIR, TEM and VSM techniques were used to characterize bare and coated nanoparticles. Results indicated that the average size of SPIONS was 8.4 nm. X-ray diffraction patterns of silica coated SPIONS were identical to that of SPIONS confirming the inner spinal structure of SPIONS. FTIR results confirmed the binding of silica with the magnetite and the formation of the silica shell around the magnetite core. Magnetic properties of SPIONS and silica coated SPIONS are determined by VSM. They are superparamagnetic. The major conclusion drawn from this study is that the synthesis route yields stable, non-aggregated magnetite-silica core-shell nanostructures with tailored morphology and excellent magnetic properties.

  13. Synthesis of water-dispersed magnetic nanoparticles (H2O-DMNPs) of β-cyclodextrin modified Fe3O4 and its catalytic application in Kabachnik-Fields multicomponent reaction

    Science.gov (United States)

    Rostamnia, Sadegh; Doustkhah, Esmail

    2015-07-01

    Water-dispersed magnetic nanoparticles (H2O-DMNPs) of β-cyclodextrin modified Fe3O4 were successfully synthesized. β-Cyclodextrin acts as stabilizer and structure directing agent of Fe3O4. Subsequently, the dispersion of Fe3O4@β-CD was applied for the Kabachnik-Fields multicomponent reaction through three-component synthesis of an amine, aldehyde, and dimethylphosphonate. β-CD had also a drastic effect in accelerating the catalysis of phosphonate synthesis. By this protocol, phosphonate derivatives were synthesized in high yields and the catalyst was recycled for 10 successful runs.

  14. A Micro Rectangular-Shaped Long-Period Fiber Grating Coated With Fe3O4 Nanoparticle Thin Overlay For Magnetic Sensing

    Directory of Open Access Journals (Sweden)

    Sheng-Feng Wang

    2015-10-01

    Full Text Available In this paper, we provide a novel micro rectangular-shaped long-period fiber grating (MRSLPFG coated with Fe3O4 nanoparticles as the sensing material and packaged in polydimethylsiloxane (PDMS for magnetic sensing application. The micro rectangular-shaped grating structures are fully dip coated with the magnetic fluid and heated to form a thin solid film. This thin overlay is used as the sensing media to measure the external magnetic flux density parallel to the optical fiber axis. According to our experimental results, the phenomenon of the transmission loss of the MRSLPFG magnetic sensor was increased monotonically when the external applied magnetic flux density increased. As the external applied magnetic flux density was increased from 0 to 91.10 mT, the resonance attenuation dip of the MRSLPFG increased and the average sensitivity achieved during the experiments was 0.129 dB/mT. We infer that the aforementioned experimental results were due to the magnetostrictive effect exerted on the thin layer of Fe3O4 nanoparticles, which in turn induced slight longitudinal strains on the micro rectangular-shaped fiber grating structures under different magnetic flux density.

  15. Gold Nanoparticles on Mesoporous SiO2-Coated Magnetic Fe3O4 Spheres: A Magnetically Separatable Catalyst with Good Thermal Stability

    Directory of Open Access Journals (Sweden)

    Huan Liu

    2013-11-01

    Full Text Available Fe3O4 spheres with an average size of 273 nm were prepared in the presence of CTAB by a solvothermal method. The spheres were modified by a thin layer of SiO2, and then coated by mesoporous SiO2 (m-SiO2 films, by using TEOS as a precursor and CTAB as a soft template. The resulting m-SiO2/Fe3O4 spheres, with an average particle size of 320 nm, a high surface area (656 m2/g, and ordered nanopores (average pore size 2.5 nm, were loaded with gold nanoparticles (average size 3.3 nm. The presence of m-SiO2 coating could stabilize gold nanoparticles against sintering at 500 °C. The material showed better performance than a conventional Au/SiO2 catalyst in catalytic reduction of p-nitrophenol with NaBH4. It can be separated from the reaction mixture by a magnet and be recycled without obvious loss of catalytic activity. Relevant characterization by XRD, TEM, N2 adsorption-desorption, and magnetic measurements were conducted.

  16. Hydrothermal synthesis of superparamagnetic and red luminescent bifunctional Fe3O4@Mn2+-doped NaYF4:Yb/Er core@shell monodisperse nanoparticles and their subsequent ligand exchange in water

    Science.gov (United States)

    Qin, Zhenli; Du, Sinan; Luo, Yang; Liao, Zhijian; Zuo, Fang; Luo, Jianbin; Liu, Dong

    2016-08-01

    We report the use of an efficient hydrothermal method to synthesize superparamagnetic and red luminescent bifunctional Fe3O4@Mn2+-doped NaYF4:Yb/Er nanoparticles (NPs) with core@shell structures via a seed-growth procedure. Oleic acid coated Fe3O4 (OA-Fe3O4) NPs were initially synthesized using a coprecipitation method. The as-synthesized OA-Fe3O4 NPs were then used as seeds, on which the red upconversion luminescent shell (Mn2+-doped NaYF4:Yb/Er) was formed. Furthermore, hydrophobic to hydrophilic surface modification of the Fe3O4@Mn2+-doped NaYF4:Yb/Er NPs was achieved via a ligand exchange method where oleic acid was displaced by a PEG phosphate ligand [PEG = poly(ethylene glycol)]. These materials were characterized by means of transmission electron microscopy (TEM), X-ray diffraction (XRD), photoluminescence (PL) spectroscopy, and vibrating sample magnetometry (VSM). The Fe3O4 cores were uniformly coated with a Mn2+-doped NaYF4:Yb/Er shell, and the bifunctional Fe3O4@Mn2+-doped NaYF4:Yb/Er NPs were monodispersed. Furthermore, the Fe3O4@Mn2+-doped NaYF4:Yb/Er NPs exhibited a saturated magnetization value of 6.2 emu/g and emitted red luminescence under a 980 nm laser. The obtained bifunctional Fe3O4@Mn2+-doped NaYF4:Yb/Er NPs may find potential applications in drug targeting, bioseparation, and diagnostic analysis. The synthetic method may be employed for the preparation of other bifunctional nanomaterials.

  17. Studies on Properties of Rice Straw/Polymer Nanocomposites Based on Polycaprolactone and Fe3O4 Nanoparticles and Evaluation of Antibacterial Activity

    Directory of Open Access Journals (Sweden)

    Roshanak Khandanlou

    2014-10-01

    Full Text Available Modified rice straw/Fe3O4/polycaprolactone nanocomposites (ORS/Fe3O4/ PCL-NCs have been prepared for the first time using a solution casting method. The RS/Fe3O4-NCs were modified with octadecylamine (ODA as an organic modifier. The prepared NCs were characterized by using X-ray powder diffraction (XRD, Scanning electron microscopy (SEM, Transmission electron microscopy (TEM, Thermogravimetric analysis (TGA and Fourier transform infrared spectroscopy (FT-IR. The XRD results showed that as the intensity of the peaks decreased with the increase of ORS/Fe3O4-NCs content in comparison with PCL peaks, the Fe3O4-NPs peaks increased from 1.0 to 60.0 wt. %. The TEM and SEM results showed a good dispersion of ORS/Fe3O4-NCs in the PCL matrix and the spherical shape of the NPs. The TGA analysis indicated thermal stability of ORS/Fe3O4-NCs increased after incorporation with PCL but the thermal stability of ORS/Fe3O4/PCL-NCs decreased with the increase of ORS/Fe3O4-NCs content. Tensile strength was improved with the addition of 5.0 wt. % of ORS/Fe3O4-NCs. The antibacterial activities of the ORS/Fe3O4/PCL-NC films were examined against Gram-negative bacteria (Escherichia coli and Gram-positive bacteria (Staphylococcus aureus by diffusion method using nutrient agar. The results indicated that ORS/Fe3O4/PCL-NC films possessed a strong antibacterial activity with the increase in the percentage of ORS/Fe3O4-NCs in the PCL.

  18. A nanocomposite consisting of graphene oxide and Fe3O4 magnetic nanoparticles for the extraction of flavonoids from tea, wine and urine samples

    International Nuclear Information System (INIS)

    We describe a single-step solvothermal method for the preparation of nanocomposites consisting of graphene oxide and Fe3O4 nanoparticles (GO/Fe3O4). This material is shown to be useful as a magnetic sorbent for the extraction of flavonoids from green tea, red wine, and urine samples. The nanocomposite is taking advantage of the high surface area of GO and the magnetic phase separation feature of the magnetic sorbent. The nanocomposite is recyclable and was applied to the extraction of flavonoids prior to their determination by HPLC. The effects of amount of surfactant, pH value of the sample solution, extraction time, and desorption condition on the extraction efficiency, and the regeneration conditions were optimized. The limits of detection for luteolin, quercetin and kaempferol range from 0.2 to 0.5 ng∙ mL−1 in urine, from 3.0 to 6.0 ng∙mL−1 in green tea, and from 1.0 to 2.5 ng∙mL−1 in red wine. The recoveries are between 82.0 and 101.4 %, with relative standard deviations of <9.3 %. (author)

  19. Bare and protein-conjugated Fe3O4 ferromagnetic nanoparticles for utilization in magnetically assisted hemodialysis: biocompatibility with human blood cells

    Science.gov (United States)

    Stamopoulos, D.; Manios, E.; Gogola, V.; Benaki, D.; Bouziotis, P.; Niarchos, D.; Pissas, M.

    2008-12-01

    Magnetically assisted hemodialysis is a development of conventional hemodialysis and is based on the circulation of ferromagnetic nanoparticle-targeted binding substance conjugates (FN-TBS Cs) in the bloodstream of the patient and their eventual removal by means of a 'magnetic dialyzer'. Presented here is an in vitro investigation on the biocompatibility of bare Fe3O4 FNs and Fe3O4-bovine serum albumin Cs with blood cells, namely red blood cells (RBCs), white blood cells (WBCs) and platelets (Plts). Atomic force microscopy (AFM) and optical microscopy (OM) enabled the examination of blood cells at the nanometer and micrometer level, respectively. The observations made on FN- and C-maturated blood samples are contrasted to those obtained on FN- and C-free reference blood samples subjected to exactly the same maturation procedure. Qualitatively, both AFM and OM revealed no changes in the overall shape of RBCs, WBCs and Plts. Incidents where bare FNs or Cs were bound onto the surface of RBCs or internalized by WBCs were very rare. Detailed examination by means of OM proved that impaired coagulation of Plts is not initiated/promoted either by FNs or Cs. Quantitatively, the statistical analysis of the obtained AFM images from RBC surfaces clearly revealed that the mean surface roughness of RBCs maturated with bare FNs or Cs was identical to the one of reference RBCs.

  20. Fabrication of cyclodextrin-functionalized superparamagnetic Fe 3O 4/amino-silane core-shell nanoparticles via layer-by-layer method

    Science.gov (United States)

    Cao, Haining; He, Jiang; Deng, Li; Gao, Xiaoqing

    2009-06-01

    This paper presents a feasible protocol for the preparation of a novel versatile nanocomposite possessing superparamagnetism via a layer-by-layer method. We combined (3-aminopropyl)triethoxysilane-coated magnetic Fe 3O 4 nanoparticles (APTES-MNPs) with β-cyclodextrin (β-CD). The following unusual features were integrated in a single nano-system: (a) the silane coating outside the magnetic Fe 3O 4 cores derived from the hydrolysis of APTES acted as a coupling agent and provided amino group (-NH 2) for linking the CD molecule; (b) the outermost CD moieties can function as inclusion sites and specific containers for drugs and biomolecules; (c) the innermost magnetic cores were able to sense and respond to an externally applied magnetic field and their behaviors in vivo or in vitro can be artificially manipulated and navigated. The obtained nanocomposite turned out to be superparamagnetic with a relatively high saturation magnetization value of 69 emu g -1, which implies potentially promising applications in magnetic drug delivery technology and bioseparation.

  1. 碳包覆 Fe3 O4纳米颗粒的制备%Synthesis of Carbon Encapsulated Magnetite Nanoparticles

    Institute of Scientific and Technical Information of China (English)

    卓姣娥; 贲向东

    2013-01-01

    以葡萄糖为碳源,以聚乙烯吡咯烷酮( PVP)为表面活性剂,在碱性条件下用水合肼还原氯化铁,采用两步水热法制备Fe3 O4/C磁性纳米粒子,并采用X-射线衍射仪( XRD)、扫描电子显微镜( SEM)、透射电子显微镜( TEM)对产物进行表征。结果表明:产物为碳包覆纳米四氧化三铁核壳结构,其直径为300~600 nm,晶化程度较高。%Carbon encapsulated magnetite nanoparticles are synthesized via hydrothermal process two -step synthesis method with glucose for carbon sources, PVP for surfactant, and hydrazine hydrate as reducing agent for ferric chloride in alkaline condi-tion.The morphologies and structures of the products are characterized by X -ray diffraction (XRD),scanning electron microsco-py (SEM) and transmission electron microscopy (TEM).The Fe3O4/C core-shell materials with the diameters of 300~600nm, which have a high crystallization degree.

  2. 超顺磁性Fe3O4壳聚糖纳米粒制备影响因素的初步研究%Influencing factors for preparation of superparamagnetic Fe3O4 chitosan nanoparticle

    Institute of Scientific and Technical Information of China (English)

    谢鸿蒙; 罗聪; 贾运涛; 黄华

    2014-01-01

    目的:制备超顺磁性Fe3O4壳聚糖纳米粒,探究不同表面活性剂及交联剂等因素对纳米粒形成及其理化性质的影响.方法:化学共沉淀法制备纳米粒,激光粒度仪检测其粒径大小、聚合物分散指数(polydispersity index,PDI)、zeta电位,振动样品磁强计检测其磁化强度.结果:制备的纳米粒粒径大小在15~60 nm之间,平均粒径29.39 nm,PDI为0.185,zeta电位绝对值约20,磁感应性良好.结论:亲水亲油平衡值(hydrophile lipophilic balance,HLB)较小的表面活性剂能减小纳米粒粒径,交联剂戊二醛用量需控制在1.5~2.0 ml,NaOH溶液浓度需控制在3.0~4.0 mol/L.

  3. Superhydrophobic and Magnetic Fe3O4/Polydopamine Composite Nanoparticle and Its Oil/Water Separation%超疏水磁性Fe3O4/聚多巴胺复合纳米颗粒及其油/水分离

    Institute of Scientific and Technical Information of China (English)

    梁伟欣; 王贵元; 王奔; 张亚斌; 郭志光

    2013-01-01

    借助于多巴胺在Fe3O4纳米颗粒表面自聚合形成聚多巴胺薄膜制备出Fe3O4/聚多巴胺(Fe3O4/PD)复合纳米颗粒,利用扫描电子显微镜、透射电子显微镜、X射线衍射仪对样品的形貌、结构及成分进行分析.所制备的颗粒经1H,1H,2H,2H-全氟癸基三氯硅烷化学修饰后表现出超疏水性.有趣的是,超疏水性的Fe3O4/PD纳米颗粒包裹在水滴表面能形成磁性液珠,该液珠(4 μL)在亲水性玻璃表面上的接触角高达164°、滚动角为8°.这些磁性液珠具有良好的机械稳定性和强度,同时研究了外部磁场驱动液珠在平面、曲面、油相中运动.结果表明,磁性液珠能够有效应用于操作微流体装置中的液体输送.水滴在Fe3O4/PD纳米颗粒构成表面的接触角超过150°,而油滴则接近0°,因此,在磁场存在下,这些颗粒能用于吸收油水混合物中的油滴而实现油水分离.此外,回收的Fe3O4/PD纳米颗粒保持着超疏水性且能再次利用.%We report a simple approach to creating bifunctional Fe3O4/polydopamine (Fe3O4/PD) composite nanoparticles (NPs) with both superparamagnetic and superhydrophobic properties. The Fe3O4/PD NPs were prepared by virtue of dopa-mine self-polymerization under mild conditions. Their morphology, structure and composition of nanocomposites were analyzed by scanning electron microscopy (SEM), transmission electron microscopy (TEM), X-ray diffraction (XRD), respectively. The Fe3O4/PD NPs have uniform sizes in a narrow range of 100~300 nm. Magnetic measurement reveals the Fe3O4/PD NPs are superparamagnetic with saturation magnetization of 73.40 emu/g. The as-prepared particles showed su-perhydrophobicity after being modified by lH,lH,2H,2H-perfluorodecyltrichlorosilane. The Fe3O4 particles were also modified by fiuoroalkylsilane, and surface composed of the particles present a water contact angle (CA) of 117 °. This result indicated that plenty of phenolic hydroxyl groups in

  4. Facile synthesis of Fe3O4 nanoparticles decorated on 3D graphene aerogels as broad-spectrum sorbents for water treatment

    Science.gov (United States)

    Li, Yong; Zhang, Ruofang; Tian, Xike; Yang, Chao; Zhou, Zhaoxin

    2016-04-01

    In order to develop efficient and environment benign sorbents for water purification, the macroscopic multifunctional magnetite-reduced graphene oxides aerogels (M-RGOs) with strong interconnected networks were prepared via a one pot solvothermal method of graphene oxide sheets adsorbing iron ions and in situ simultaneous deposition of Fe3O4 nanoparticles in ethylene glycol or triethylene glycol solvents. Such M-RGOs exhibited excellent sorption capacity to different contaminants, including oils, organic solvents, arsenite ions, as well as dyes. In addition, it was demonstrated that the M-RGOs could be used as column packing materials to manufacture column for water purification by filtration. The method proposed was proved to be versatile to induce synergistic assembly of RGO sheets with other functional metal oxides nanoparticles and as a kind of broad-spectrum sorbents for removing different types of contaminants in water purification, simultaneously.

  5. 不同表面修饰的Fe3O4纳米颗粒在体肿瘤成像研究%In vivo MR imaging of tumor by using Fe3O4 nanoparticles bearing with different surface ligand as contrast agent

    Institute of Scientific and Technical Information of China (English)

    乔瑞瑞; 刘侃; 贾兵; 曾剑峰; 欧阳汉; 王凡; 高明远

    2011-01-01

    Objective: To compare the contrast effect for MR imaging of tumor by using two types of Fe3O4 nanoparticles bearing with different surface ligands as tumor-targeting contrast agent.Methods: The tumor-targeting peptide c(RGDyK) was conjugated with Fe3O4 nanoparticles bearing with carboxylic groups by the conjugation reaction mediated by EDC and sulfo-NHS.Then, the conjugates were applied to in vivo detecting tumors in BALB/ c nude mice bearing U-87 MG human glioma cancer xenografts.Results and Conclusion: The two different types of Fe3O4 nanoparticles both can obtain obvious contrast effect, however, the best contrast images had to be acquired at different time.For particles bearing with PEG and oleyamine, the best contrast images can be acquired at 8 h after injection, while for particles bearing with PEG, it was 4 h after injection, which may be affected by the different surface charge of the Fe3O4 nanoparticles.%目的:比较两种不同表面修饰的Fe3O4纳米颗粒作为肿瘤探针进行在体磁共振成像(MRI)的区别.方法:采用两种不同表面修饰的Fe3O4作为磁共振造影剂,并利用其表面羧基与具有靶向识别肿瘤表面整合素受体(Integrin αvβ3)的c(RGDyK)多肽进行耦联,制备出具有肿瘤靶向性的磁共振分子探针.以荷人脑胶质瘤(U-87 MG)裸鼠为动物模型,进行体内MRI研究.结果与结论:两种纳米颗粒均能够产生明显的T2造影效果,表面为聚乙二醇及油胺共同修饰的纳米颗粒的最佳成像时间为注射药物后8 h,而只有聚乙二醇修饰的纳米颗粒的最佳成像时间为注射药物后4 h,导致两种纳米颗粒在成像时达到最佳成像效果的时间不同的原因在于其表面电荷的不同.

  6. Superparamagnetism and metamagnetic transition in Fe3O4 nanoparticles synthesized via co-precipitation method at different pH

    International Nuclear Information System (INIS)

    In the present work, Fe3O4 nanoparticles have been synthesized via low temperature co-precipitation method at different pH (7.0, 11.0 and 12.4) with the aim to study the variation of pH on the structural, optical and magnetic properties of samples. Further, the sample synthesized at pH ~12.4 has been annealed at 230 °C for 10 h to study the effect of annealing on structural, optical and magnetic properties. X-ray diffraction (XRD) results reveal the formation of pure spinel phase with the space group Fd-3m. Further, XRD, FESEM and TEM results confirm the nanocrystalline nature of the as synthesized samples, and the particle size of the samples decreases as the pH increases and increases after annealing at 230 °C. FTIR analysis indicates that the sample synthesized at pH ~12.4 and the same sample annealed at 230 °C are pure spinel Fe3O4, whereas the samples synthesized at pH ~7.0 and 11.0 have small content of α-Fe2O3. The optical measurements of the as synthesized samples show two band gaps in all synthesized samples. Field dependent magnetization measurements (M–H) reveal superparamagnetic nature of all the synthesized samples at room temperature and ferromagnetic behavior at low temperature (~5 K). Furthermore, M–H plots measured at 5 K show presence of metamagnetic transition in all samples. The metamagnetic transition along with ferromagnetic behavior at low temperature in Fe3O4 nanoparticles are observed first time in the present work to the best of our knowledge. Further the value of magnetization decreases with decreasing particle size at both temperatures. The fitting of the field cooled (FC) temperature dependent magnetization (M–T) measurements data with modified Bloch-spin wave model with additional surface disorder term and mixed magnetic phases indicates surface spin disorder and mixed magnetic phases in the as synthesized samples, which may be the possible reason for the existence of metamagnetic transition in the samples. The correlation

  7. Study on synthesis of poly(GMA)-grafted Fe3O4/SiOX magnetic nanoparticles using atom transfer radical polymerization and their application for lipase immobilization

    International Nuclear Information System (INIS)

    Functionalized superparamagnetic particles were prepared by atom transfer radical polymerization of glycidyl methacrylate onto the surface of modified Fe3O4/SiOX nanoparticles. The obtained particles were characterized by X-ray powder diffraction (XRD), transmission electron microscopy (TEM), Fourier transform infrared spectroscopy (FT-IR) and vibrating sample magnetometer (VSM). Candida rugosa lipase was covalently immobilized on the magnetic particles in mild condition via covalent binding with a higher activity recovery. The resulting immobilized lipase had better resistance to pH and temperature inactivation in comparison to free lipase, the adaptive pH and temperature ranges of lipase were widened, and it exhibited good thermal stability and reusability.

  8. Reduction of hematite with ethanol to produce magnetic nanoparticles of Fe3O4, Fe1 - x O or Fe0 coated with carbon

    Science.gov (United States)

    Tristão, Juliana C.; Ardisson, José D.; Sansiviero, Maria Terezinha C.; Lago, Rochel M.

    2010-01-01

    The production of magnetic nanoparticles of Fe3O4 or Fe0 coated with carbon and carbon nanotubes was investigated by the reduction of hematite with ethanol in a Temperature Programmed Reaction up to 950°C. XRD and Mössbauer measurements showed after reaction at 350°C the partial reduction of hematite to magnetite. At 600°C the hematite is completely reduced to magnetite (59%), wüstite (39%) and metallic iron (7%). At higher temperatures, carbide and metallic iron are the only phases present. TG weight losses suggested the formation of 3-56 wt.% carbon deposits after reaction with ethanol. It was observed by SEM images a high concentration of nanometric carbon filaments on the material surface. BET analyses showed a slight increase in the surface area after reaction. These materials have potential application as catalyst support and removal of spilled oil contaminants.

  9. Microfluidic assisted synthesis of multi-functional polycaprolactone microcapsules: incorporation of CdTe quantum dots, Fe3O4 superparamagnetic nanoparticles and tamoxifen anticancer drugs.

    Science.gov (United States)

    Yang, C-H; Huang, K-S; Lin, Y-S; Lu, K; Tzeng, C-C; Wang, E-C; Lin, C-H; Hsu, W-Y; Chang, J-Y

    2009-04-01

    This paper demonstrates a proof-of-concept approach for encapsulating the anticancer drug tamoxifen, Fe3O4 nanoparticles (NPs) and CdTe quantum dots (QDs) into size-controlled polycaprolactone (PCL) microcapsules utilizing microfluidic emulsification, which combined magnetic targeting, fluorescence imaging and drug controlled release properties into one drug delivery system. Cross-linking the composite PCL microcapsules with poly(vinyl alcohol) (PVA) tailored their size, morphology, optical and magnetic properties and drug release behaviors. The flow conditions of the two immiscible solutions were adjusted in order to successfully generate various sizes of polymer droplets. The result showed superparamagnetic and fluorescent properties, and was used as a controlled drug release vehicle. The composite magnetic and fluorescent PCL microcapsules are potential candidates for a smart drug delivery system. PMID:19294308

  10. Synthesis and characterization of Mn0.5Zn0.5Fe2O4 and Fe3O4 nanoparticle ferrofluids for thermo-electric conversion

    Science.gov (United States)

    Sansom, C. L.; Jones, P.; Dorey, R. A.; Beck, C.; Stanhope-Bosumpim, A.; Peterson, J.

    2013-06-01

    Ferrofluids containing nanoparticles of Mn0.5Zn0.5Fe2O4 (MZ5) and Fe3O4 (magnetite) have been examined as potential thermal transport media and energy harvesting materials. The ferrofluids were synthesized by chemical co-precipitation and characterized by EDX to determine composition and by TEM to determine particle size and agglomeration. A range of particle coatings and carrier fluids were used to complete the fluid preparation. Commercially available ferrofluids were tested in custom built rigs to demonstrate both thermal pumping (for waste heat removal applications) and power induction (for power conversion and energy harvesting applications). The results indicate that simple ferrofluids possess the necessary properties to remove waste heat, either into thermal storage or for conversion to electrical power.

  11. Targeted delivery and pH-responsive release of stereoisomeric anti-cancer drugs using β-cyclodextrin assemblied Fe3O4 nanoparticles

    Science.gov (United States)

    Wang, Congli; Huang, Lizhen; Song, Shengmei; Saif, Bassam; Zhou, Yehong; Dong, Chuan; Shuang, Shaomin

    2015-12-01

    The β-cyclodextrin assemblied magnetic Fe3O4 nanoparticles (β-CD-MNPs) were successfully fabricated via a layer-by-layer method. Possessing an average size 14 nm, good stability and super-paramagnetic response (Ms 64 emu/g), the resultant nanocomposites could be served as a versatile biocompatible platform for selective loading, targeted delivery and pH-responsive release of stereoisomeric doxorubicin (DOX) and epirubicin (EPI). 1H-nuclear magnetic resonance (1H NMR) and the computer simulation further give the evidence that partial anthracene ring of drug molecule is included by β-CD. In addition, non-toxic β-CD-MNPs have excellent biocompatibility on MCF-7 cells, and cellular uptake indicate that different amounts of DOX or EPI can be transported to targeting site and released from the internalized carriers. The results demonstrate that as-prepared β-CD-MNPs could be a very promising vehicle for DOX and EPI.

  12. Optimization of adsorption process of Cadmium ions from synthetic wastewater using synthesized iron magnetic nanoparticles (Fe3O4

    Directory of Open Access Journals (Sweden)

    Leila Karimi Takanlu

    2014-10-01

    Conclusion: Magnetite nanoparticles exhibit high capability for removal of cadmium. The nanoparticles synthesized could be used at industrial scale because of having the magnetic property, which make them easily recovered from aqueous solution through applying a magnetic field.

  13. 超顺磁性Fe3O4纳米粒子的制备和表征%Preparation and Characterization of Super-paramagnetic Fe304 Nanoparticles

    Institute of Scientific and Technical Information of China (English)

    文德; 刘妙丽; 李强林

    2011-01-01

    超顺磁性的Fe3O4纳米颗粒,因其具有许多独特的性质和潜在的应用前景,引起了人们的极大关注,是材料研究领域的一个持续热点.采用共沉淀法制得纳米Fe3O4,通过XRD、SEM等对样品进行表征,用VSM对样品进行磁性能测试.结果表明所得样品为纯反尖晶石结构的Fe3O4球形颗粒,平均粒径约为15nm.磁性能测试表明当外加磁场为6 kOe时,Fe3O4纳米粒子的磁化达到饱和,饱和磁化强度为63 A·m2·kg-1.在室温下,所制Fe3O4纳米粒子显示典型的超顺磁性,在生物医学、磁记录材料、磁流体复合材料、催化剂等方面有着潜在的应用前景.%The superparamagnetic Fe3O4 nanoparticle has been attracting great attention and is an important topic in the field of advanced materials, owing to its many unique properties and potential applications. In this paper, the superparamagnetic Fe3O4 nanoparticles were synthesized by the coprecipitation method, the prepared samples were characterized by X-ray diffraction(XRD) and scanning electron microscopy( SEM), the magnetic properties measurement was performed by VSM. The results indicate that the average diameter of the spherical Fe3O4 with pure anti-spinel structure is i5 nm, and that magnetization of the magnetic powders get to saturation, the saturated magnetization is 63 A · m2 · kg-1 when the external field is at 6 kOe. The prepared Fe3O4 nanoparticles show a typical superparamagnetism at room temperature, there are enormous potential applications for the superparamagnetic Fe3O4 nanoparticles in various fields, such as biomedicine, information storage, magnetic fluids, catalysts, and so on.

  14. An amperometric acetylcholinesterase sensor based on Fe3O4 nanoparticle/multi-walled carbon nanotube-modified ITO-coated glass plate for the detection of pesticides

    International Nuclear Information System (INIS)

    Highlights: ► Constructed AChE biosensor based on AChE/Fe3O4NPs/c-MWCNT/ITO electrode. ► Enzyme electrode was characterized by AFM, FTIR, CV and EIS. ► Detection limit and working range of biosensor were 0.1 nM and 0.1–100 nM. ► Half life of enzyme electrode was 3 months. ► Biosensor measured pesticides in environmental and food samples. - Abstract: A method is described for the construction of a highly sensitive electrochemical biosensor for the detection of malathion, chlorpyrifos, monocrotophos and endosulfan based on covalent immobilization of acetylcholinesterase (AChE) on iron oxide nanoparticles (Fe3O4NPs)-decorated carboxylated multi-walled carbon nanotubes (c-MWCNTs) electrodeposited onto indium tin oxide (ITO)-coated glass plate. Transmission electron microscopic (TEM) and UV analysis of nanocomposite materials demonstrated that Fe3O4NPs were well deposited on the outer walls of c-MWCNTs. The modified electrode was characterized by atomic force microscopy (AFM), cyclic voltammetry (CV), Fourier transform infrared (FTIR) spectroscopy and electrochemical impedance spectroscopy (EIS). The resulting biosensor exhibited a linear response for acetylthiocholine in a concentration range of 0.1–700 μmol L−1 with a remarkable sensitivity of 0.402 mA/μmol L−1. Under optimum conditions, the inhibition rates of pesticides were proportional to their concentrations in the range of 0.1–70 nmol L−1, 0.1–50 nmol L−1, 0.1–70 nmol L−1 and 0.1–100 nmol L−1 for malathion, chlorpyrifos, monocrotophos and endosulfan, respectively. The detection limit of the biosensor for all pesticides was 0.1 nmol L−1 at a signal-to-noise ratio of 3. The biosensor showed good reproducibility, no interference by metal ions and long-term stability. The measurement results obtained by the present biosensor were in good agreement with those obtained by the standard gas chromatography–mass spectrometry method. The biosensor was employed for the determination

  15. D, L-Sulforaphane Loaded Fe3O4@ Gold Core Shell Nanoparticles: A Potential Sulforaphane Delivery System

    Science.gov (United States)

    Kheiri Manjili, Hamidreza; Ma’mani, Leila; Tavaddod, Sharareh; Mashhadikhan, Maedeh; Shafiee, Abbas; Naderi-Manesh, Hossein

    2016-01-01

    A novel design of gold-coated iron oxide nanoparticles was fabricated as a potential delivery system to improve the efficiency and stability of d, l-sulforaphane as an anticancer drug. To this purpose, the surface of gold-coated iron oxide nanoparticles was modified for sulforaphane delivery via furnishing its surface with thiolated polyethylene glycol-folic acid and thiolated polyethylene glycol-FITC. The synthesized nanoparticles were characterized by different techniques such as FTIR, energy dispersive X-ray spectroscopy, UV-visible spectroscopy, scanning and transmission electron microscopy. The average diameters of the synthesized nanoparticles before and after sulforaphane loading were obtained ∼ 33 nm and ∼ 38 nm, respectively, when ∼ 2.8 mmol/g of sulforaphane was loaded. The result of cell viability assay which was confirmed by apoptosis assay on the human breast cancer cells (MCF-7 line) as a model of in vitro-cancerous cells, proved that the bare nanoparticles showed little inherent cytotoxicity, whereas the sulforaphane-loaded nanoparticles were cytotoxic. The expression rate of the anti-apoptotic genes (bcl-2 and bcl-xL), and the pro-apoptotic genes (bax and bak) were quantified, and it was found that the expression rate of bcl-2 and bcl-xL genes significantly were decreased when MCF-7 cells were incubated by sulforaphane-loaded nanoparticles. The sulforaphane-loaded into the designed gold-coated iron oxide nanoparticles, acceptably induced apoptosis in MCF-7 cells. PMID:26982588

  16. Superparamagnetic Fe3 O4 @SiO2 core-shell composite nanoparticles for the mixed hemimicelle solid-phase extraction of benzodiazepines from hair and wastewater samples before high-performance liquid chromatography analysis.

    Science.gov (United States)

    Esmaeili-Shahri, Effat; Es'haghi, Zarrin

    2015-12-01

    Magnetic Fe3 O4 /SiO2 composite core-shell nanoparticles were synthesized, characterized, and applied for the surfactant-assisted solid-phase extraction of five benzodiazepines diazepam, oxazepam, clonazepam, alprazolam, and midazolam, from human hair and wastewater samples before high-performance liquid chromatography with diode array detection. The nanocomposite was synthesized in two steps. First, Fe3 O4 nanoparticles were prepared by the chemical co-precipitation method of Fe(III) and Fe(II) as reaction substrates and NH3 /H2 O as precipitant. Second, the surface of Fe3 O4 nanoparticles was modified with shell silica by Stober method using tetraethylorthosilicate. The Fe3 O4 /SiO2 composite were characterized by X-ray diffraction, scanning electron microscopy, Fourier transform infrared spectroscopy, and vibrating sample magnetometry. To enhance their adsorptive tendency toward benzodiazepines, cetyltrimethylammonium bromide was added, which was adsorbed on the surface of the Fe3 O4 /SiO2 nanoparticles and formed mixed hemimicelles. The main parameters affecting the efficiency of the method were thoroughly investigated. Under optimum conditions, the calibration curves were linear in the range of 0.10-15 μgmL(-1) . The relative standard deviations ranged from 2.73 to 7.07%. The correlation coefficients varied from 0.9930 to 0.9996. PMID:26412451

  17. Poly(N-isopropylacrylamide)-gated Fe3O4/SiO2 core shell nanoparticles with expanded mesoporous structures for the temperature triggered release of lysozyme.

    Science.gov (United States)

    Yu, Erick; Galiana, Irene; Martínez-Máñez, Ramón; Stroeve, Pieter; Marcos, María D; Aznar, Elena; Sancenón, Félix; Murguía, José R; Amorós, Pedro

    2015-11-01

    Core-shell nanoparticles comprised of Fe3O4 cores and a mesoporous silica shell with an average expanded pore size of 6.07 nm and coated with a poly(N-isopropylacrylamide) (PNIPAM) layer (CS-MSNs-EP-PNIPAM) were prepared and characterized. The nanoparticles was loaded with (Ru(bipy)3(2+)) dye or an antibacterial enzyme, lysozyme, to obtain CS-MSNs-EP-PNIPAM-Ru(bipy)3(2+) and CS-MSNs-EP-PNIPAM-Lys, respectively. The lysozyme loading was determined to be 160 mg/g of nanoparticle. It was seen that Ru(bipy)3(2+) and lysozyme release was minimal at a room temperature of 25 °C while at physiological temperature (37 °C), abrupt release was observed. The applicability of the CS-MSNs-EP-PNIPAM-Lys was further tested with two Gram-positive bacteria samples, Bacillus cereus and Micrococcus luteus. At physiological temperature, the nanoparticles were shown to reduce bacterial growth, indicating a successful release of lysozyme from the nanoparticles. This nanoparticle system shows potential as a nanocarrier for the loading of similarly sized proteins or other species as a drug delivery platform. PMID:26335056

  18. Synthesis of amino-silane modified superparamagnetic Fe3O4 nanoparticles and its application in immobilization of lipase from Pseudomonas fluorescens Lp1

    International Nuclear Information System (INIS)

    Highlights: ► Magnetic nanoparticles were synthesized by chemical co-precipitation method. ► Surface was functionalized with amino-silane and used for lipase immobilization. ► Characterized through TEM, SEM, XRD, FT-IR and VSM analysis. ► The functionalization and immobilization did not affect the magnetite properties. ► The immobilized lipase showed greater functional property than free lipase. - Abstract: Superparamagnetic nanoparticles (Fe3O4–magnetite) were prepared by chemical co-precipitation method and their surface was functionalized with 3-aminopropyltriethoxysilane via silanization reaction to obtain amino functionalized magnetic nanoparticles. The purified lipase from Pseudomonas fluorescens Lp1 was immobilized onto functionalized magnetite using glutaraldehyde as the coupling agent. The characterization of the nanoparticles was done by scanning electron microscopy, transmission electron microscopy, powder X-ray diffraction, vibrating sample magnetometry and Fourier transformed infrared spectroscopy. The size of the magnetite was measured about 10–30 nm. The results of characterization study revealed the successful immobilization of lipase on to functionalized magnetite. The saturation magnetization of magnetic nanoparticles was found to be 28.34 emu/g whereas the immobilized magnetic nanoparticle was 17.074 emu/g. The immobilized lipase had greater activity at 50 °C and thermal stability upto 70 °C. It exhibited excellent reusability for 4 cycles and storage stability upto 15 days by retaining 75% of its initial activity

  19. Preparation of Self-assembled Fe3O4@SiO2 Composite Nanoparticles with Multi-magnetic Cores from Electrospun Nanofibers%电纺纳米纤维自组装制备含多磁性内核的Fe3O4@SiO2核壳结构纳米粒

    Institute of Scientific and Technical Information of China (English)

    张培培; 田利强; 娄少峰; 王斌; 权静; 聂华丽; 朱利民

    2013-01-01

    The self-assembled Fe3O4 @SiO2 composite nanoparticles with multi-magnetic cores were prepared from electrospun nanofibers. The morphology of electrospun nanofibers was observed by SEM. The appearance, size distribution, phase, chemical composition and magnetic characteristics of nanoparticles were characterized by FE-SEM, TEM, FT-IR, XRD and VSM, respectively. The results showed that the composite nanoparticles were in a sphere-like form. And there were many magnetic cores inside them. The size distribution of the microspheres averaged about 50 nm and the main phase of microspheres were amporphous SiO2 and crystalline Fe3O4. The composite nanoparticles retained superparamagnetic behavior and could be used as biomaterials.%通过电纺纳米纤维自组装制备了含多磁性内核的Fe3O4@SiO2核壳结构纳米粒.采用扫描电镜(SEM)表征了电纺纳米纤维的形貌,利用场发射扫描电镜(FE-SEM)、透射电镜(TEM)、傅里叶红外光谱仪(FT-IR)、X晶体衍射仪(XRD)和振动样品磁强计(VSM)分别对纳米粒的形貌、粒度分布、物相组成、化学成分和磁性能等进行了表征.结果显示:采用电纺纳米纤维自组装制备的Fe3O4@SiO2纳米粒为近似球形的结构,其内含有多个磁性内核;粒径分布在50 nm左右,主要物相是无定形的SiO2和晶态的Fe3O4,保持了磁性粒子的超顺磁性,是一种优良的生物磁性材料.

  20. Fe3O4磁性纳米粒子-氧化石墨烯复合材料的可控制备及结构与性能表征%Controlled Synthesis and Characterization of the Structure and Property of Fe3O4 Nanoparticle-Graphene Oxide Composites

    Institute of Scientific and Technical Information of China (English)

    张燚; 陈彪; 杨祖培; 张智军

    2011-01-01

    首先利用高温分解法制备了粒径为18 nm的Fe3O4磁性纳米粒子,并进行羧基化修饰,然后与聚乙烯亚胺(PEI)化学修饰的氧化石墨烯进行交联反应,得到磁功能化的氧化石墨烯(MGO)复合材料.研究了氧化石墨烯片上的磁性纳米粒子的可控负载及其对复合材料磁性能的影响.利用透射电子显微镜(TEM),原子力显微镜(AFM),X射线衍射(XRD),傅里叶变换红外(FT-IR)光谱,热重分析(TGA),振荡样品磁强计(VSM)等手段对MGO复合材料的形貌,结构和磁性能进行了表征.结果表明,我们发展的MGO复合材料的制备方法具有简单、可控的优点,所制备的MGO复合材料具有较高的超顺磁性.该类磁性氧化石墨烯复合材料有望在磁靶向药物、基因输运、磁共振造影以及磁介导的生物分离和去除环境污染物等领域获得广泛的应用.%Fe3O4 nanoparticle-graphene oxide (MGO) composites were prepared by chemically binding carboxylic acid-modified Fe3O4 nanoparticles to polyethylenimine-functionalized graphene oxide (GO).The structure, morphology, and magnetic properties of the composites were characterized by transmission electron microscopy (TEM), atomic force microscopy (AFM), X-ray diffraction (XRD), Fourier transform infrared (FT-IR) spectroscopy, thermogravimetric analysis (TGA), and vibrating sample magnetometry (VSM).The results show that the Fe3O4 nanoparticle content in the MGO composites can be easily controlled by changing the ratio of Fe3O4 nanoparticles to GO in the reaction mixture.The MGO composites obtained are superparamagnetic with high saturation magnetization, which can potentially be applied in magnetic targeted drug delivery, gene transport, magnetic resonance imaging, bioseparation, and magnetic guided removal of aromatic contaminants in waste water and in other fields.

  1. Sub-10 nm Fe3O4@Cu2-xS core-shell nanoparticles for dual-modal imaging and photothermal therapy

    KAUST Repository

    Tian, Qiwei

    2013-06-12

    Photothermal nanomaterials have recently attracted significant research interest due to their potential applications in biological imaging and therapeutics. However, the development of small-sized photothermal nanomaterials with high thermal stability remains a formidable challenge. Here, we report the rational design and synthesis of ultrasmall (<10 nm) Fe3O 4@Cu2-xS core-shell nanoparticles, which offer both high photothermal stability and superparamagnetic properties. Specifically, these core-shell nanoparticles have proven effective as probes for T 2-weighted magnetic resonance imaging and infrared thermal imaging because of their strong absorption at the near-infrared region centered around 960 nm. Importantly, the photothermal effect of the nanoparticles can be precisely controlled by varying the Cu content in the core-shell structure. Furthermore, we demonstrate in vitro and in vivo photothermal ablation of cancer cells using these multifunctional nanoparticles. The results should provide improved understanding of synergistic effect resulting from the integration of magnetism with photothermal phenomenon, important for developing multimode nanoparticle probes for biomedical applications. © 2013 American Chemical Society.

  2. A Novel DNA Nanosensor Based on CdSe/ZnS Quantum Dots and Synthesized Fe3O4 Magnetic Nanoparticles

    Directory of Open Access Journals (Sweden)

    Roozbeh Hushiarian

    2014-04-01

    Full Text Available Although nanoparticle-enhanced biosensors have been extensively researched, few studies have systematically characterized the roles of nanoparticles in enhancing biosensor functionality. This paper describes a successful new method in which DNA binds directly to iron oxide nanoparticles for use in an optical biosensor. A wide variety of nanoparticles with different properties have found broad application in biosensors because their small physical size presents unique chemical, physical, and electronic properties that are different from those of bulk materials. Of all nanoparticles, magnetic nanoparticles are proving to be a versatile tool, an excellent case in point being in DNA bioassays, where magnetic nanoparticles are often used for optimization of the hybridization and separation of target DNA. A critical step in the successful construction of a DNA biosensor is the efficient attachment of biomolecules to the surface of magnetic nanoparticles. To date, most methods of synthesizing these nanoparticles have led to the formation of hydrophobic particles that require additional surface modifications. As a result, the surface to volume ratio decreases and nonspecific bindings may occur so that the sensitivity and efficiency of the device deteriorates. A new method of large-scale synthesis of iron oxide (Fe3O4 nanoparticles which results in the magnetite particles being in aqueous phase, was employed in this study. Small modifications were applied to design an optical DNA nanosensor based on sandwich hybridization. Characterization of the synthesized particles was carried out using a variety of techniques and CdSe/ZnS core-shell quantum dots were used as the reporter markers in a spectrofluorophotometer. We showed conclusively that DNA binds to the surface of ironoxide nanoparticles without further surface modifications and that these magnetic nanoparticles can be efficiently utilized as biomolecule carriers in biosensing devices.

  3. Investigation of superparamagnetic (Fe3O4) nanoparticles and magnetic field exposures on CHO-K1 cell line

    Science.gov (United States)

    Coker, Zachary; Estlack, Larry; Hussain, Saber; Choi, Tae-Youl; Ibey, Bennett L.

    2016-03-01

    Rapid development in nanomaterial synthesis and functionalization has led to advanced studies in actuation and manipulation of cellular functions for biomedical applications. Often these actuation techniques employ externally applied magnetic fields to manipulate magnetic nanomaterials inside cell bodies in order to drive or trigger desired effects. While cellular interactions with low-frequency magnetic fields and nanoparticles have been extensively studied, the fundamental mechanisms behind these interactions remain poorly understood. Additionally, modern investigations on these concurrent exposure conditions have been limited in scope, and difficult to reproduce. This study presents an easily reproducible method of investigating the biological impact of concurrent magnetic field and nanoparticle exposure conditions using an in-vitro CHO-K1 cell line model, with the purpose of establishing grounds for in-depth fundamental studies of the mechanisms driving cellular-level interactions. Cells were cultured under various nanoparticle and magnetic field exposure conditions from 0 to 500 μg/ml nanoparticle concentrations, and DC, 50 Hz, or 100 Hz magnetic fields with 2.0 mT flux density. Cells were then observed by confocal fluorescence microscopy, and subject to biological assays to determine the effects of concurrent extreme-low frequency magnetic field and nanoparticle exposures on cellnanoparticle interactions, such as particle uptake and cell viability by MTT assay. Current results indicate little to no variation in effect on cell cultures based on magnetic field parameters alone; however, it is clear that deleterious synergistic effects of concurrent exposure conditions exist based on a significant decrease in cell viability when exposed to high concentrations of nanoparticles and concurrent magnetic field.

  4. A novel hydrothermal approach for synthesizing α-Fe2O3, γ-Fe2O3 and Fe3O4 mesoporous magnetic nanoparticles

    International Nuclear Information System (INIS)

    A novel method to synthesize the three phases of iron oxide nanoparticles (hematite, maghemite and magnetite) using the same non-toxic inorganic precursors via a water–organic interface under the low temperature hydrothermal conditions is reported. The synthesized particles are characterized by Powder X-ray Diffraction (XRD), Field Emission Scanning Electron Microscopy (FESEM) and Transmission Electron Microscopy (TEM). The Brunauer–Emmett–Teller (BET) results reveal the mesoporous nature of the particles. The magnetic properties of the nanoparticles are studied by Vibrating Sample Magnetometer (VSM) at various low temperatures and also at room temperature. The XRD peaks corresponding to each sample clearly depict the presence of the respective phase of the as-prepared magnetic nanoparticles. The nanoparticles of maghemite and magnetite have saturation magnetization of 58.56 and 40.30 emu/g respectively at room temperature, whereas the particles of hematite possess very low saturation magnetization value of 1.89 emu/g. Further, the magnetization is studied at four different temperatures and the zero field cooled (ZFC) and field cooled (FC) magnetization are reported. - Graphical abstract: Display Omitted - Highlights: • Hematite, maghemite and magnetite are obtained under hydrothermal synthesis. • α-Fe2O3, γ-Fe2O3 and Fe3O4 prepared are mesoporous and nearly monodisperse. • Near superparamagnetism is observed at room temperature for maghemite and magnetite

  5. Studies on Properties of Rice Straw/Polymer Nanocomposites Based on Polycaprolactone and Fe3O4 Nanoparticles and Evaluation of Antibacterial Activity

    OpenAIRE

    Roshanak Khandanlou; Ahmad, Mansor B.; Kamyar Shameli; Elnaz Saki; Katayoon Kalantari

    2014-01-01

    Modified rice straw/Fe3O4/polycaprolactone nanocomposites (ORS/Fe3O4/ PCL-NCs) have been prepared for the first time using a solution casting method. The RS/Fe3O4-NCs were modified with octadecylamine (ODA) as an organic modifier. The prepared NCs were characterized by using X-ray powder diffraction (XRD), Scanning electron microscopy (SEM), Transmission electron microscopy (TEM), Thermogravimetric analysis (TGA) and Fourier transform infrared spectroscopy (FT-IR). The XRD results showed th...

  6. Fe3O4纳米粒子-氧化石墨烯纳米复合物的制备、表征及体外毒性评价%Preparation, Characterization and in vitro Cytotoxicity Evaluation of Fe3O4 Nanoparticles Decorated Graphene Oxide

    Institute of Scientific and Technical Information of China (English)

    刘琼; 王娟; 陈秀华

    2013-01-01

    The Fe3O4 magnetic nanoparticles decorated graphene oxide (GO) composites were in situ synthesized by co-precipitation method with the GO sheets prepared by improved Hummers method. The properties of the composites were characterized by transmission electron microscope (TEM), Fourier transform infrared spectroscopy (FT-IR) and X-ray diffraction (XRD). The results showed that the mean particle size of the Fe3O4 nanoparticles in the composites was 30 run, and some aggregates were 50 - 100 ran. Some functional groups of GO in the composites could be used as the sites binding with the drugs. The composites could also load drugs by Π-Π conjugation. In the presence of external magnetic field, the prepared composites rapidly gathered near the permanent magnet. The results of in vitro cytotoxicity test showed that in the concentration range of 0.5 - 5 000 ng/ml, the composites had no obvious cytotoxicity on lung cancer cells A549 and breast cancer cells ZR-75-30.%采用改进的Hummers方法制备氧化石墨烯(GO),再用共沉淀法原位合成Fe3O4磁性纳米粒子修饰的GO复合材料.通过透射电镜(TEM)、傅里叶变换红外光谱(FT-IR)和X-射线衍射(XRD)对Fe3O4纳米粒子-GO复合物的形态进行表征.结果表明,所制复合物中Fe3O4磁性纳米粒子的粒径为30 nm,少量粒子团聚后的粒径为50~100nm.该复合物中GO含有多种官能团,可作为药物连接的位点,还可通过π-π共轭作用与药物连接.在外加磁场作用下,可明显观察到该复合物迅速聚集在永磁体附近.体外细胞毒性试验表明,该复合物在0.5~5 000 μg/ml范围内对肺癌A549细胞和乳腺癌ZR-75-30细胞无细胞毒性.

  7. Synthesis, characterization and application of polyglycerol coated Fe3O4 nanoparticles as a nano-theranostics agent

    Science.gov (United States)

    Jahandar, Marzieh; Zarrabi, Ali; Shokrgozar, Mohammad Ali; Mousavi, Hajar

    2015-12-01

    Superparamagnetic iron oxide nanoparticles (SPIONs) with an average size of 10 nm have been successfully synthesized by the polyol method. Then, hyperbranched polyglycerol (HPG) branches have been introduced on the surface of SPIONs through ring opening polymerization of glycidol as a biocompatible surface modifier with a more hydrophilic nature than other biomedical polymers. The as-synthesized SPION-HPGs were analyzed by FT-IR, CHNS and TGA analysis which all exhibited the successful HPG grafting onto the SPION surface. The anticancer herbal drug, curcumin, was loaded on the resultant nanocarrier. The MTT assay demonstrated the non-cytotoxicity effect of SPION-HPGs and the low cytotoxicity effect of curcumin at low concentrations on L929 and MCF-7 cell lines as normal and cancerous cells, respectively. Moreover, these nanoparticles exhibited an improved effect as a contrast agent in magnetic resonance imaging. Thus, it is concluded that SPION-HPG has the potential to be used in theranostics applications due to its simultaneous drug delivery and imaging capabilities.

  8. Magnetic loading of TiO2/SiO2/Fe3O4 nanoparticles on electrode surface for photoelectrocatalytic degradation of diclofenac

    International Nuclear Information System (INIS)

    Highlights: ► Magnetic TSF nanoparticles are immobilized on electrode surface with aid of magnet. ► Magnetically attached TSF electrode shows high photoelectrochemical activity. ► Diclofenac is effectively degraded on TSF-loaded electrode by photoelectrocatalysis. ► Photoelectrocatalytic degradation of diclofenac is monitored with voltammetry. - Abstract: A novel magnetic nanomaterials-loaded electrode developed for photoelectrocatalytic (PEC) treatment of pollutants was described. Prior to electrode fabrication, magnetic TiO2/SiO2/Fe3O4 (TSF) nanoparticles were synthesized and characterized by X-ray diffraction (XRD), transmission electron microscopy (TEM) and FT-IR measurements. The nanoparticles were dispersed in ethanol and then immobilized on a graphite electrode surface with aid of magnet to obtain a TSF-loaded electrode with high photoelectrochemical activity. The performance of the TSF-loaded electrode was tested by comparing the PEC degradation of methylene blue in the presence and absence of magnet. The magnetically attached TSF electrode showed higher PEC degradation efficiency with desirable stability. Such a TSF-loaded electrode was applied to PEC degradation of diclofenac. After 45 min PEC treatment, 95.3% of diclofenac was degraded on the magnetically attached TSF electrode.

  9. Protein adsorption onto Fe3O4 nanoparticles with opposite surface charge and its impact on cell uptake

    CERN Document Server

    Catalayud, M P; Raffa, V; Riggio, C; Ibarra, M R; Goya, G F

    2014-01-01

    Nanoparticles (NPs) engineered for biomedical applications are meant to be in contact with protein-rich physiological fluids. These proteins are usually adsorbed onto the NP surface, forming a swaddling layer called protein corona that influences cell internalization. We present a study on protein adsorption onto different magnetic NPs (MNPs) when immersed in cell culture medium, and how these changes affect the cellular uptake. Two colloids with magnetite cores of 25 nm, same hydrodynamic size and opposite surface charge were in situ coated with (a) positive polyethyleneimine (PEI-MNPs) and (b) negative poly(acrylic acid) (PAA-MNPs). After few minutes of incubation in cell culture medium the wrapping of the MNPs by protein adsorption resulted in a 5-fold size increase. After 24 h of incubation large MNP-protein aggregates with hydrodynamic sizes 1500 to 3000 nm (PAA-MNPs and PEI-MNPs respectively) were observed. Each cluster contained an estimated number of magnetic cores between 450 and 1000, indicating the...

  10. Magnetorelaxometry of few Fe3O4 nanoparticles at 77 K employing a self-compensated SQUID magnetometer

    Science.gov (United States)

    Guillaume, Alexander; Scholtyssek, Jan M.; Lak, Aidin; Kassner, Alexander; Ludwig, Frank; Schilling, Meinhard

    2016-06-01

    Magnetic nanoparticles (MNPs) are of great interest for industrial and medical applications. Therefore, the properties of the particles have to be well controlled. Several magnetic measurement schemes have been developed in order to determine particle parameters such as size distribution and structural properties. In general, systems are designed either for the analysis of large amounts of MNP (≫1000) or for single particle investigation. Up to now, the region in between has been less studied. However, small and well defined amounts of MNPs are of high interest, e.g. for the systematic investigation of particle-particle interactions. In this paper, we present a method using electron beam lithographic preparation of small amounts of MNPs directly on a self-compensating high-temperature superconducting quantum interference device (SQUID) with micrometer dimensions which is insensitive to homogeneous fields and first order gradients but very sensitive to internal magnetic dipole fields. Magnetorelaxometry (MRX) measurements were carried out at 77 K sample temperature in a magnetically shielded room in order to analyze the dynamic behavior of MNP samples and to evaluate the detection limit of our SQUID sensors. Calculations based on the magnetic moment superposition model (MSM) and finite element simulations (FEM) indicate that the MNP samples can be fabricated in a well-defined way by the presented method. Based on MRX measurements of a sample with 200 single-core magnetite MNPs with core diameters of 12 nm, we estimate the detection limit of our SQUID MRX setup as 70 MNPs.

  11. Photocatalytic Property of Fe3O4/SiO2/TiO2 Core-Shell Nanoparticle with Different Functional Layer Thicknesses

    Directory of Open Access Journals (Sweden)

    Junyang Li

    2014-01-01

    Full Text Available This study examined the different properties of Fe3O4/SiO2/TiO2 (FST core-shell nanoparticles encapsulated for one to five different times, represented as FST1 to FST5, respectively. These FST nanoparticles were obtained using the carbon reduction and sol-gel methods, and their properties were characterized by various tools, such as scanning electron microscopy, transmission electron microscopy, X-ray diffraction, vibratory sample magnetometer, laser granularity apparatus, and specific surface area analyzer. The relationship between irradiation time and decoloration ratio indicates that FST2 demonstrated significant efficiency in the decolorization of methyl orange (MO under UV light. Further study on recycle activity showed that FST2 had a high decoloration rate after four cycles of photocatalysis, and its degradation of MO was well aligned with the apparent first-order kinetic equation. Furthermore, FST2 exhibited the highest apparent rate in the first cycle. All these results demonstrate that the recoverable FST2 possessed excellent photocatalytic activity while maintaining outstanding stability for further applications, such as managing environmental pollution.

  12. Surfactant-free green synthesis of Fe3O4 nanoparticles capped with 3,4-dihydroxyphenethylcarbamodithioate: stable recyclable magnetic nanoparticles for the rapid and efficient removal of Hg(II) ions from water.

    Science.gov (United States)

    Venkateswarlu, Sada; Yoon, Minyoung

    2015-11-14

    Mercury is considered one of the most notorious global pollutants due to its high toxicity and widespread use in industry. Although many materials have been developed for the removal of mercury for water purification, most of these materials are difficult to reuse, which may lead to an increase in the mercury handling expense. Therefore, new sustainable materials that can be easily recycled and are highly efficient for the removal of mercury are required. Herein, we report the surfactant-free green synthesis of Fe3O4 magnetic nanoparticles (MNPs) using a watermelon (Citrullus lanatus) rind extract. The Fe3O4 MNPs were further functionalized with 3,4-dihydroxyphenethylcarbamodithioate (DHPCT) and applied to the removal of Hg(ii). Evaluation of the mercury removal efficiency and the amount adsorbed by DHPCT@Fe3O4 MNPs demonstrated a high Hg(ii) removal efficiency (98%) with a maximum Hg(ii) adsorption capacity of 52.1 mg g(-1). Systematic studies of the adsorption mechanism and selectivity suggest that the soft ligand (DHPCT) can preferentially coordinate with the soft metal ion (Hg(ii)) resulting in selective mercury removal. The developed DHPCT@Fe3O4 MNPs were readily recycled several times using an external magnet by exploiting their ferromagnetic character, without a significant decline in the Hg(ii) removal efficiency. This study provides a new insight into the preparation of a highly efficient adsorbent for Hg(ii) removal by an eco-friendly method. PMID:26436867

  13. Body distribution of SiO2-Fe3O4 core-shell nanoparticles after intravenous injection and intratracheal instillation.

    Science.gov (United States)

    Smulders, Stijn; Ketkar-Atre, Ashwini; Luyts, Katrien; Vriens, Hanne; De Sousa Nobre, Sonia; Rivard, Camille; Van Landuyt, Kirsten; Baken, Stijn; Smolders, Erik; Golanski, Luana; Ghosh, Manosij; Vanoirbeek, Jeroen; Himmelreich, Uwe; Hoet, Peter Hm

    2016-06-01

    Nano-silicon dioxide (SiO2) is used nowadays in several biomedical applications such as drug delivery and cancer therapy, and is produced on an industrial scale as additive to paints and coatings, cosmetics and food. Data regarding the long-term biokinetics of SiO2 engineered nanoparticles (ENPs) is lacking. In this study, the whole-body biodistribution of SiO2 core-shell ENPs containing a paramagnetic core of Fe3O4 was investigated after a single exposure via intravenous injection or intratracheal instillation in mice. The distribution and accumulation in different organs was evaluated for a period of 84 days using several techniques, including magnetic resonance imaging, inductively coupled plasma mass spectrometry, X-ray fluorescence and X-ray absorption near edge structure spectroscopy. We demonstrated that intravenously administered SiO2 ENPs mainly accumulate in the liver, and are retained in this tissue for over 84 days. After intratracheal instillation, an almost complete particle clearance from the lung was seen after 84 days with distribution to spleen and kidney. Furthermore, we have strong evidence that the ENPs retain their original core-shell structure during the whole observation period. This work gives an insight into the whole-body biodistribution of SiO2 ENPs and will provide guidance for further toxicity studies. PMID:26525175

  14. Facile synthesis of magnetic-/pH-responsive hydrogel beads based on Fe3O4 nanoparticles and chitosan hydrogel as MTX carriers for controlled drug release.

    Science.gov (United States)

    Wu, Juan; Jiang, Wei; Tian, Renbing; Shen, Yewen; Jiang, Wei

    2016-10-01

    In the present study, methotrexate (MTX)-encapsulated magnetic-/pH-responsive hydrogel beads based on Fe3O4 nanoparticles and chitosan were successfully prepared through a one-step gelation process, which is a very facile, economic and environmentally friendly route. The developed hydrogel beads exhibited homogeneous porous structure and super-paramagnetic responsibility. MTX can be successfully encapsulated into magnetic chitosan hydrogel beads, and the drug encapsulation efficiency (%) and encapsulation content (%) were 93.8 and 6.28%, respectively. In addition, the drug release studies in vitro indicated that the MTX-encapsulated magnetic chitosan hydrogel beads had excellent pH-sensitivity, 90.6% MTX was released from the magnetic chitosan hydrogel beads within 48 h at pH 4.0. WST-1 assays in human liver hepatocellular carcinoma cells (HepG2) demonstrated that the MTX-encapsulated magnetic chitosan hydrogel beads had good cytocompatibility and high anti-tumor activity. Therefore, our results revealed that the MTX-encapsulated magnetic chitosan hydrogel beads would be a competitive candidate for controlled drug release in the area of targeted cancer therapy in the near future. PMID:27464586

  15. β-cyclodextrin functionalized poly (5-amidoisophthalicacid) grafted Fe3O4 magnetic nanoparticles: A novel biocompatible nanocomposite for targeted docetaxel delivery

    Science.gov (United States)

    Tarasi, Roghayeh; Khoobi, Mehdi; Niknejad, Hassan; Ramazani, Ali; Ma'mani, Leila; Bahadorikhalili, Saeed; Shafiee, Abbas

    2016-11-01

    Thiol-lactam initiated radical polymerization (TLIRP) was successfully employed to prepare poly-N-5-acrylamidoisophthalicacid grafted onto Fe3O4 magnetic nanoparticles (MNPs@PAIP). β-Cyclodextrin (CD) was then conjugated to the carboxylic groups of the prepared MNPs via carbodiimide activation. Subsequently, tumor-targeting folic acid (FA) was attached to the hydroxyl groups of CD on the surface of the latter MNPs to increase the site-specific intracellular delivery. The prepared MNPs were fully characterized by FTIR, VSM, TGA, XRD, FE-SEM and TEM. Docetaxel (DTX) as hydrophobic anticancer drug was loaded via host-guest inclusion complexation with CD and the release profile of the system was studied at different pH. The effect of MNPs on the cell viability was evaluated for the human embryonic kidney normal cell line (HEK293) as well as HeLa and MDA-MB-231 cancerous cell lines and the results did not show any apparent cytotoxic effect. In comparison, DTX loaded MNPs reduced the growth of HeLa and MDA-MB-231 cells more than free DTX. Intracellular uptake ability of DTX loaded MNPs was also studied using fluorescent microscopy and showed cellular uptake about 90% after 4 h treatment.

  16. Preparation of thermo and pH-responsive polymer@Au/Fe3O4 core/shell nanoparticles as a carrier for delivery of anticancer agent

    International Nuclear Information System (INIS)

    In this work, a thermo and pH-responsive poly-N-isopropylacrylamide-co-itaconic acid containing thiol side groups were successfully synthesized to prepare Doxorubicin-loaded polymer@Au/Fe3O4 core/shell nanoparticles (DOX-NPs). Copolymer and NPs were fully characterized by FT-IR, HNMR, photo-correlation spectroscopy, SEM, X-ray diffraction, vibrating-sample magnetometer, thermal gravimetric analysis, and UV–Vis spectroscopy. The stimuli-responsive characteristics of NPs were evaluated by in vitro release study in simulated cancerous environment. The biocompatibility and cytotoxic properties of NPs and DOX-NPs are explored by MTT method. The prepared NPs with the size of 50 nm showed paramagnetic characteristics with suitable and stable dispersion at physiological medium and high loading capacity (up to 55 %) of DOX. DOX-NPs yielded a pH- and temperature-triggered release of entrapped drugs at tumor tissue environment (59 % of DOX release) compared to physiological condition (20 % of DOX release) during 48 h. In vitro cytotoxicity studies indicated that the NPs showed no cytotoxicity on A549 cells at different amounts after incubation for 72 h confirming its suitability as a drug carrier. DOX-NPs, on the other hand, caused an efficient anticancer performance as verified by MTT assay test. It was concluded that developed NPs by us in this study may open the possibilities for targeted delivery of DOX to the cancerous tissues

  17. Facile preparation of amino functionalized graphene oxide decorated with Fe3O4 nanoparticles for the adsorption of Cr(VI)

    Science.gov (United States)

    Zhao, Donglin; Gao, Xuan; Wu, Changnian; Xie, Rong; Feng, Shaojie; Chen, Changlun

    2016-10-01

    A novel ternary magnetic composite consisting of graphene oxide (GO), diethylenetriamine and Fe3O4 nanoparticles (AMGO) were synthesized by a facile one-step reaction route and characterized. The AMGO was applied as a magnetic adsorbent for the Cr(VI) removal from aqueous solutions and the magnetic separation process only took 40 s. The maximum adsorption capacity of the AMGO for Cr(VI) was 123.4 mg/g, displaying a high efficiency for the removal of Cr(VI), which was much higher than that of MGO. The removal process was pH dependence, endothermic and spontaneous. The pseudo-second-order model described well the adsorption kinetic data and the Langmuir isotherm model fitted the experimental data better than the Freundlich isotherm model. XPS analysis revealed that the Cr(VI) was reduced to the low-toxicity Cr(III) during the adsorption process. Both the Cr(VI) adsorption and subsequent reduction of adsorbed Cr(VI) to Cr(III) contributed to the Cr(VI) removal. In addition, the excellent reproducibility indicate that the AMGO may be a promising adsorption material for the separation and preconcentration of Cr(VI) ions from aqueous solutions in environmental pollution cleanup.

  18. Development of a facile and effective electrochemical strategy for preparation of iron oxides (Fe3O4 and γ-Fe2O3) nanoparticles from aqueous and ethanol mediums and in situ PVC coating of Fe3O4 superparamagnetic nanoparticles for biomedical applications

    Science.gov (United States)

    Karimzadeh, Isa; Dizaji, Hamid Rezagholipour; Aghazadeh, Mustafa

    2016-10-01

    To attain reliable and high performance in biomedical applications, magnetic particles with regular spherical shape, narrow size distributions, high-saturation magnetization, and good dispersion in liquid media is very important. Therefore, the synthesis of monodispersed, water-dispersible, and regular spherical superparamagnetic iron oxides nanoparticles (SPIONs) with high saturation magnetization will be of great importance. Here we report a facile, fact and simple electrochemical tactic for preparation of SPIONs and their one step in situ surface engineering in both aqueous and ethanol mediums. In this platform, optimum and simple electrochemical conditions were first constructed for preparation of Fe3O4 and γ-Fe2O3 nanoparticles in both ethanol and aqueous mediums, and monodispersed nanoparticles with superparamagnetic properties were prepared. The field emission scanning and transmission electron microscopy (FE-SEM and TEM) observations revealed that the electrodeposited nanoparticles have roughly spherical and homogeneous shape with narrow size distribution. Then, Fe3O4 nanoparticles were coated by polyvinyl chloride (PVC) during deposition process. The PVC coating on SPIONs surface was confirmed by Fourier transform infrared spectroscopy (FT-IR), dynamic light scattering (DLS), differential scanning calorimetry (DSC), and thermogravimetric (TG) analyses. Results of vibrating sample magnetometer (VSM) indicated that the prepared SPIONs exhibit superparamagnetic behavior including negligible remnant magnetization and negligible coercivity, and high saturation magnetization at room temperature. PVC coated SPIONs exhibited saturation magnetization value of 43.72 emu/g, and negligible remnant magnetization and coercivity (Mr~0.15 emu/g and Ce~0.5 Oe, respectively). Based on the obtained results, it was concluded this electrochemical strategy can be introduced as a novel and clean platform for preparation of variety polymer and drug coated/loaded SPIONs for

  19. Study of the intra-arterial distribution of Fe3O4 nanoparticles in a model of colorectal neoplasm induced in rat liver by MRI and spectrometry

    Directory of Open Access Journals (Sweden)

    Echevarria-Uraga JJ

    2012-05-01

    Full Text Available José J Echevarria-Uraga,1 Ignacio García-Alonso,2 Fernando Plazaola,3 Maite Insausti,3 Néstor Etxebarria,3 Alberto Saiz-López,4 Begoña Fernández-Ruanova51Radiology Department, Hospital de Galdakao-Usánsolo, Bizkaia, Spain; 2Experimental Surgery Laboratory, Medicine Faculty, University of the Basque Country, Bizkaia, Spain; 3Faculty of Science and Technology, University of the Basque Country, Bizkaia, Spain; 4Pathology Department, Hospital de Galdakao-Usánsolo, Bizkaia, Spain; 5Osatek SA Unidad del Hospital de Galdakao-Usánsolo, Bizkaia, SpainPurpose: To evaluate, in an experimental model, the reliability of MRI for determining whether a higher iron concentration was obtained in tumor tissue than in normal liver parenchyma after intra-arterial administration of Fe3O4 lipophilic nanoparticles.Materials and methods: WAG/RijCrl rats were inoculated in the left hepatic lobe with 25,000 syngeneic CC-531 colon adenocarcinoma cells, after which they were randomized into two groups: control (CG and infused (IG. After confirming tumor induction, the IG rats received intra-arterial suspensions of Fe3O4 nanoparticles (2.6 mg in Lipiodol® (0.15 mL. To calculate the iron concentration, [Fe], in the tumor and liver tissues of both groups of rats, measurements of signal intensity from the tumors, healthy liver tissue, and paravertebral muscles were made on a 1.5T MRI system in gradient-echo DP* and T2*-weighted sequences. In addition, samples were collected to quantify the [Fe] by inductively coupled plasma-mass spectrometry (ICP-MS, as well as for histological analysis. Statistical analysis was performed with non-parametric tests, and Bland–Altman plots were produced; P values <0.05 were considered significant.Results: In the CG rats (n = 23, the mean [Fe] values estimated by MRI and ICP-MS were 13.2 µmol • g-1 and 5.9 µmol • g-1, respectively, in the tumors, and 19.0 µmol • g-1 and 11.7 µmol • g-1, respectively, in the hepatic tissue

  20. Effects of combined delivery of extremely low frequency electromagnetic field and magnetic Fe3O4 nanoparticles on hepatic cell lines.

    Science.gov (United States)

    Ju, Huixiang; Cui, Yubao; Chen, Zhiqiang; Fu, Qinping; Sun, Mingzhong; Zhou, Ying

    2016-01-01

    Magnetic Fe3O4 nanoparticles (MNPs) have shown promise as drug carriers for treating lung and liver tumors in vivo. However, little is known about the combined delivery of these MNPs with a second approach, extremely low frequency electro-magnetic field (ELFF) exposure, which has been shown to have value for in vitro treatment of tumor cells. Here, ELFF and MNPs were combined to treat healthy (HL-7702) and cancerous (Bel-7402, HepG2) hepatic cells lines to explore the potential therapeutic effects, bio-mechanisms, and potential toxicity of a combined drug-free treatment in vitro. Flow cytometry for anti-AFP (alpha fetal protein) antibody, which coated the MNPs, indicated that the combined treatment induced Bel-7402 and HepG2 hepatoma cells lines into early apoptosis, without significant effects on healthy hepatic cells. This effect appeared to be mediated through cellular membrane ion metabolism. The presence of AFP-loaded MNPs strengthened the effects of ELFF on tumor cells, inducing a higher frequency of early apoptosis, while having minimal toxic effects on healthy HL-7702 cells. Western blotting revealed that the apoptosis-triggering BCL proteins were up regulated in hepatoma cells compared to healthy cells. Flow cytometry and patch-clamp studies revealed that this resulted from a higher MNP uptake ratio and greater cellular membrane ion exchange current in tumor cells compared to HL-7702 cells. Further, patch-clamp results showed that combining MNPs with ELFF treatment induces cells into early apoptosis through an ion metabolism disturbance in cells, similar to ELFF treatment. In brief, the combination of ELFF and MNPs had beneficial effects on tumor cells without significant toxicity on healthy cells, and these effects were associated with cellular MNP uptake. PMID:27186307

  1. Fe3O4 nanoparticle loaded paclitaxel induce multiple myeloma apoptosis by cell cycle arrest and increase cleavage of caspases in vitro

    International Nuclear Information System (INIS)

    Multiple myeloma (MM) still remains an incurable disease in spite of extending the patient survival by new therapies. The hypothesis of cancer stem cells (CSCs) states that although chemotherapy kills most tumor cells, it is believed to leave a reservoir of CSCs that allows the tumor cell propagation. The objective of this research was to evaluate the therapeutic effect of new paclitaxel-Fe3O4 nanoparticles (PTX-NPs) with an average size range of 7.17 ± 1.31 nm on MM CSCs in vitro. The characteristics of CD138−CD34− cells, isolated from human MM RPMI 8226 and NCI-H929 cell lines by the magnetic associated cell sorting method, were identified by the assays of colony formation, cell proliferation, drug resistance, cell migration, and tumorigenicity in non-obese diabetic/severe combined immunodeficiency (NOD/SCID) mice, respectively. Inhibitory effects of PTX-NPs on CD138−CD34− cells were evaluated by a variety of assays in vitro. The results showed that the CD138−CD34− cells were capable of forming colonies, exhibited high proliferative and migratory ability, possessed a strong drug resistance, and had powerful tumorigenicity in NOD/SCID mice compared to non-CD138−CD34− cells. PTX-NPs significantly inhibited CD138− CD34− cell viability and invasive ability, and resulted in G0/G1 cell cycle arrest and apoptosis compared with PTX alone. We concluded that the CD138−CD34− phenotype cells might be CSCs in RPMI 8226 and NCI-H929 cell lines. PTX-NPs had an obvious inhibitory effect on MM CD138−CD34− CSCs. The findings may provide a guideline for PTX-NPs’ treatment of MM CSCs in preclinical investigation

  2. Biocompatible polyurethane/thiacalix[4]arenes functionalized Fe3O4 magnetic nanocomposites: Synthesis and properties.

    Science.gov (United States)

    Mohammadi, Abbas; Barikani, Mehdi; Lakouraj, Moslem Mansour

    2016-09-01

    In this study, a series of magnetic polyurethane/Fe3O4 elastomer nanocomposites were prepared by covalently embedding novel thiacalix[4]arenes (TC4As) functionalized Fe3O4 nanoparticles (TC4As-Fe3O4) which contain macrocycles with reactive hydroxyl groups. Surface functionalization of Fe3O4 nanoparticles with TC4As macrocycles as unique reactive surface modifier not only gives specific characteristics to Fe3O4 nanoparticles but also improves the interphase interaction between nanoparticles and the polyurethane matrices through covalent attachment of polymer chains to nanoparticle surfaces. The novel synthesized TC4As-Fe3O4 nanoparticles were characterized by FTIR, XRD, TGA, VSM and SEM analysis. Furthermore, the effect of functionalization of Fe3O4 nanoparticles on the various properties of resulting nanocomposites was studied by XRD, TGA, DMTA, SEM, and a universal tensile tester. It was found that the functionalization of nanoparticles with TC4As affords better mechanical and thermal properties to polyurethane nanocomposites in comparison with unmodified nanoparticles. The SEM analysis showed finer dispersion of TC4As-Fe3O4 nanoparticles than unmodified Fe3O4 nanoparticles within the polyurethane matrices, which arising from formation of covalent bonding between TC4As functionalized Fe3O4 nanoparticles and polyurethane matrices. Moreover, the investigation of in vitro biocompatibility of novel nanocomposites showed that these samples are excellent candidate for biomedical use. PMID:27207044

  3. Adsorption Studies on Aqueous Cd2 +, Pb2+, Cu2 + Ions by Thiol and Humic Acid Functionalized Fe3O4 Nanoparticles%巯基修饰和胡敏酸包裹纳米Fe3O4颗粒的制备及其对溶液中pb2+ Cd2+ Cu2+的吸附效果研究

    Institute of Scientific and Technical Information of China (English)

    王萌; 雷丽萍; 方敦煌; 徐照丽; 陈世宝

    2011-01-01

    采用改进的化学共沉淀法制备纳米Fe3O4颗粒,利用3-巯丙基三乙氧基硅烷(MPTES)和胡敏酸(HA)对所制备的纳米Fe3O4进行巯基修饰和胡敏酸包裹,通过红外光谱(IR)、X射线衍射分析(XRD)等方法对上述制备的纳米颗粒的性质进行了表征,同时对上述不同的纳米Fe3O4颗粒在恒温下对水体中金属离子(Pb2+、Cd2+、Cu2+)的吸附进行了研究.结果表明,所制备的功能化前后的纳米Fe3O4纯度较高,平均粒径约为20~30 nm,且分布均匀.不同纳米型Fe3O4颗粒对溶液中金属离子具有较好的吸附性能,其吸附等温线均可以用Langmuir方程进行较好的拟合;裸露的纳米Fe3O4颗粒对Pb2+最大吸附量(b)达到172.4 mg·g-1,经过胡敏酸包裹后的纳米Fe3O4颗粒对Cd2+、Cu2+的最大吸附量分别增加了75.8%和231.5%;对不同金属离子而言,裸露的和巯基修饰的纳米Fe3O4对3种重金属离子的吸附能力的强弱为pb2+>Cd2+>Cu2+,而经胡敏酸包裹后的顺序则为Pb2+>Cu2,Cd2+;与裸露的和巯基修饰的纳米Fe3O4相比,经HA包裹的纳米Fe3O4对Cd2+和Cu2+具有较高的吸附量和吸附亲和力参数,而对Pb2+的吸附无显著性差异.%The magnetic Fe3O4 nanoparticles were prepared using modified chemical co- precipitation, and corresponding thiolated and coating nanoparticles were also obtained via surface mercaptopropyltriethoxysilane(MPTES) modification and humic acid(HA). The properties and structure of the nanoparticles were characterized by X-Ray diffraction(XRD) and infrared spectroscopy(IR) etc. The application of the nanoparticles to the adsorption of aqueous Pb2+, Cd2+, Cu2+ were also investigated in this study. The results showed that the average size of prepared nanoparticles were about 20-30 nm with homogeneous distribution; the nanoparticles could adsorb Pb2+, Cd2+, Cu2+ in solution efficiently and the adsorption data were well fitted with the Langmuir isotherm. The sorption maxima of

  4. Bio and Nanomaterials Based on Fe3O4

    Directory of Open Access Journals (Sweden)

    Jia-Kun Xu

    2014-12-01

    Full Text Available During the past few years, nanoparticles have been used for various applications including, but not limited to, protein immobilization, bioseparation, environmental treatment, biomedical and bioengineering usage, and food analysis. Among all types of nanoparticles, superparamagnetic iron oxide nanoparticles, especially Fe3O4, have attracted a great deal of attention due to their unique magnetic properties and the ability of being easily chemical modified for improved biocompatibility, dispersibility. This review covers recent advances in the fabrication of functional materials based on Fe3O4 nanoparticles together with their possibilities and limitations for application in different fields.

  5. Chitosan and O-carboxymethyl chitosan modified Fe3O4 for hyperthermic treatment

    Science.gov (United States)

    Thu Trang Mai, Thi; Thu Ha, Phuong; Pham, Hong Nam; Thu Huong Le, Thi; Linh Pham, Hoai; Bich Hoa Phan, Thi; Tran, Dai Lam; Phuc Nguyen, Xuan

    2012-03-01

    In this study magnetic fluids were manufactured by the adsorption of chitosan (CS) and O-carboxymethyl chitosan (OCMCS) on Fe3O4 nanoparticles to be used as hyperthermic thermoseeds. Fe3O4 particles were characterized by physico-chemical methods such as: thermogravimetry analysis (TGA), x-ray diffraction (XRD), Raman spectrum, Fourier transform infrared spectroscopy (FTIR), scanning electron microscope (SEM) and vibrating sample magnetometer (VSM). The SEM images and XRD patterns showed that the synthesized Fe3O4 nanoparticles were of single phase and spherical shape with 10–15 nm in diameter. The VSM measurements showed that Fe3O4 particles were superparamagnetic with saturation magnetization of 70 emu g‑1. The adsorbed layers of CS and OCMCS on the magnetite surface (Fe3O4/CS) and (Fe3O4/OCMCS) were confirmed by FTIR, Raman spectra and SEM. In the ac magnetic field of 80 Oe and 236 kHz, the saturation heating temperatures of the sample Fe3O4/CS and Fe3O4/OCMCS were 100 and 98 °C, respectively. At the same concentration of Fe3O4 nanoparticles in suspension, the two magnetic fluids exhibited quite high heating capacity, with different behaviors of concentration dependence. The Fe3O4/CS and Fe3O4/OCMCS nanoparticles would serve as good thermoseeds for localized hyperthermia treatment of cancers.

  6. Chitosan and O-carboxymethyl chitosan modified Fe3O4 for hyperthermic treatment

    International Nuclear Information System (INIS)

    In this study magnetic fluids were manufactured by the adsorption of chitosan (CS) and O-carboxymethyl chitosan (OCMCS) on Fe3O4 nanoparticles to be used as hyperthermic thermoseeds. Fe3O4 particles were characterized by physico-chemical methods such as: thermogravimetry analysis (TGA), x-ray diffraction (XRD), Raman spectrum, Fourier transform infrared spectroscopy (FTIR), scanning electron microscope (SEM) and vibrating sample magnetometer (VSM). The SEM images and XRD patterns showed that the synthesized Fe3O4 nanoparticles were of single phase and spherical shape with 10–15 nm in diameter. The VSM measurements showed that Fe3O4 particles were superparamagnetic with saturation magnetization of 70 emu g−1. The adsorbed layers of CS and OCMCS on the magnetite surface (Fe3O4/CS) and (Fe3O4/OCMCS) were confirmed by FTIR, Raman spectra and SEM. In the ac magnetic field of 80 Oe and 236 kHz, the saturation heating temperatures of the sample Fe3O4/CS and Fe3O4/OCMCS were 100 and 98 °C, respectively. At the same concentration of Fe3O4 nanoparticles in suspension, the two magnetic fluids exhibited quite high heating capacity, with different behaviors of concentration dependence. The Fe3O4/CS and Fe3O4/OCMCS nanoparticles would serve as good thermoseeds for localized hyperthermia treatment of cancers

  7. Synthesis and modification of superparamagnetic magnetic nanoparticles%超顺磁性Fe3O4纳米颗粒的制备及修饰

    Institute of Scientific and Technical Information of China (English)

    李文章; 李洁; 丘克强; 曾恒志

    2007-01-01

    利用2-吡咯烷酮和乙酰丙酮铁为原料制备出Fe3O4磁性纳米粒子,选择偶联剂γ-氨丙基三乙氧基硅烷(NH2C3H6Si(OC2H5)3)对磁性材料进行了表面修饰.经XRD、TEM、VSM、FT-IR测试结果表明,制备出的Fe3O4磁性纳米粒子粒径均一(8~10nm)、结晶度高、磁响应较强;通过控制反应回流时间,可以改变粒子的大小;经表面改性以后,-OH、-NH、-NH2、-C-O、-C-OH等多种功能基团负载到磁性Fe3O4纳米粒子表面,增强了微球的生物相容性.

  8. A highly efficient nano-Fe3O4 encapsulated-silica particles bearing sulfonic acid groups as a solid acid catalyst for synthesis of 1,8-dioxo-octahydroxanthene derivatives

    International Nuclear Information System (INIS)

    The functionalization of silica-coated Fe3O4 magnetic nanoparticles (Fe3O4@SiO2) using chlorosulfonic acid were afforded sulfonic acid-functionalized magnetic Fe3O4 nanoparticles (Fe3O4@SiO2–SO3H) that can be applied as an organic–inorganic hybrid heterogeneous catalyst. The used Fe3O4 magnetic nanoparticles are 18–30 nm sized that was rapidly functionalized and can be used as catalyst in organic synthesis. The prepared nanoparticles were characterized by X-ray diffraction analysis, magnetization curve, scanning electron microscope, dynamic laser scattering, and FT-IR measurements. The resulting immobilized catalysts have been successfully used in the synthesis of 1,8‐dioxo-octahydroxanthene derivatives under solvent free condition. This procedure has many advantages such as; a much milder method, a shorter reaction time, a wide range of functional group tolerance, and absence of any tedious workup or purification. Other remarkable features include the catalyst can be reused at least five times without any obvious change in its catalytic activity. This procedure also avoids hazardous reagents/solvents, and thus can be an eco-friendly alternative to the existing methods.Graphical AbstractA highly efficient nano-Fe3O4 encapsulated-silica particles bearing sulfonic acid groups as a solid acid catalyst for synthesis of 1,8-dioxo-octahydroxanthene derivatives

  9. The research on magnetic force excitation deformation of PDMS membrane which mixed Fe3 O4 nanoparticles%混有Fe3O4纳米颗粒的PDMS薄膜磁力激励变形研究∗

    Institute of Scientific and Technical Information of China (English)

    段俊萍; 王春水; 张斌珍; 王万军

    2014-01-01

    采用聚二甲基硅氧烷(PDMS)为基体,以经硅烷偶联剂(KH-570)处理过的20 nm Fe3 O4纳米颗粒为填充物,将这两种材料以不同比例进行混合得到磁性 PDMS 薄膜,对该磁性薄膜受力进行理论分析,用微米X射线三维成像系统测试同一永磁铁激励下不同半径、支撑腔体不同高度下(磁性薄膜距离永磁铁高度)和Fe3 O4纳米颗粒不同质量分数下磁性薄膜的变形大小,以及不同表面磁场强度的永磁铁激励下磁性薄膜的变形大小,通过振动样品磁强计对磁性薄膜样品的磁滞曲线进行了检测,实验结果表明,在相同的激励下半径越大、支撑腔体高度越小、质量分数越大薄膜中心位移越大,不同激励下永磁铁磁场强度越大薄膜中心位移的也越大,与理论分析一致。薄膜变形引起空腔内的体积变化,体积变化证明了薄膜驱动液体的能力,该实验为应用于微流体中的微泵提供了理论依据。%This paper adopt the PDMS as matrix,the Fe3 O4 nanoparticles of 20 nm modified with the silane cou-pling agent (KH-570)as fillers,the magnetic polydimethylsiloxane(PDMS)membrane obtain through two kinds of material which was mixed in different proportions,The stress of magnetic membrane was analyzed the-oretically,then test the deflection of magnetic membrane under the supporting cavity of different radius,differ-ent height of the support cavity(the distance between magnetic membrane and permanent magnet),different magnetic field,different mass fraction of Fe3 O4 nanoparticles with the help of micro X-ray three-dimensional imaging system,the same time hysteresis curve of magnetic was tested to PDMS membrane by vibrating sample magnetometer(VSM).The experiments show under the same excitation,the magnetic membrane center deflec-tion was larger under the condition of supporting cavity of larger radius,shorter height,and bigger mass frac-tion,under the different excitation

  10. Synthesis, Characterization and Photocatalytic Degradation for Coking Wastewater of Fe3O4 Nanoparticles/Bentonite%纳米Fe3O4/膨润土的制备、表征及光催化降解焦化废水

    Institute of Scientific and Technical Information of China (English)

    鲁云洲; 王光华; 李文兵; 董晴雯; 陈坤

    2013-01-01

    以铝柱撑膨润土负载纳米Fe3O4制备出性能良好的复合型催化剂.结合X射线粉末衍射(XRD)、扫描电镜(SEM)和比表面孔隙分析(BET)对催化剂的晶相、比表面积和粒度进行表征.负载的纳米Fe3O4粒径约为20~30 nm,均匀分散到膨润土表面,未发生明显的团聚.在紫外光作用下用该催化剂对焦化厂二沉池出水进行深度处理.结果表明,在催化剂投加量为0.7 g/L,pH为2.5,温度40℃,H2O2初始浓度为17.6 mmol/L的反应条件下,二沉池出水(化学需氧量COD=140 mg/L,色度=400度)经催化氧化降解后,COD和色度可分别降低到54.44 mg/L和10度,达到国家工业再生用水水质标准GB/T 19923-2005(COD≤60 mg/L,色度≤30度).催化剂重复使用4次时,废水COD和色度去除率保持稳定.%Al-pillared clays supported Fe3O4 nanoparticles were prepared as composite catalyst. XRD, BET and SEM were used to study its microstructure, surface area and average particle size. The supported Fe3O4 nanoparticles with a size about 20-30 nm existed on the surface of clays, with better dispersing and no obvious aggregation than that without bentonite support. The obtained catalyst was applied for advanced treatment of sedimentation tank effluent of coking process under UV. Results indicated that COD and chroma of the wastewater could be reduced from 140 mg/L and 400 to 54.44 mg/L and 10 respectively in the conditions as catalyst dosage 0.7 g/L, initial pH 2.5, temperature 40 t and initial H2O2 concentration 17.6 mmol/L, which could satisfy the recycled water standard of GB/T 19923-2005 with COD less than 60 mg/L and chroma less than 30. The removal rates of COD and chroma in 4 cycles remained stable.

  11. Enhanced stability and catalytic activity of immobilized α-amylase on modified Fe3O4 nanoparticles for potential application in food industries

    International Nuclear Information System (INIS)

    Enzymes play an essential role in catalyzing various reactions. However, their instability upon repetitive/prolonged use, elevated temperature, acidic or alkaline pH remains an area of concern. α-Amylase, a widely used enzyme in food industries for starch hydrolysis, was covalently immobilized on the surface of two developed matrices, amino-functionalized silica-coated magnetite nanoparticles (AFSMNPs) alone and covered with chitosan. The synthesis steps and characterizations of NPs were examined by FT-IR, VSM, and SEM. Modified nanoparticles with average diameters of 20–80 nm were obtained. Enzyme immobilization efficiencies of 89 and 74 were obtained for AFSMNPs and chitosan-coated AFSMNPs, respectively. The optimum pH obtained was 6.5 and 8.0 for the enzyme immobilized on AFSMNPs and chitosan-coated AFSMNPs, respectively. Optimum temperature for the immobilized enzyme shifted toward higher temperatures. Considerable enhancements in thermal stabilities were observed for the immobilized enzyme at elevated temperatures up to 80 °C. A frequent use experiment demonstrated that the immobilized enzyme retained 74 and 85 % of its original activity even after 20 times of repeated use in AFSMNPs and chitosan-coated AFSMNPs, respectively. Storage stability demonstrated that free enzyme lost its activity completely within 30 days. But, immobilized enzyme on AFSMNPs and chitosan-coated AFSMNPs preserved 65.73 and 78.63 % of its initial activity, respectively, after 80 days of incubation. In conclusion, a substantial improvement in the performance of the immobilized enzyme with reference to the free enzyme was obtained. Furthermore, the relative activities of immobilized enzyme are superior than free enzyme over the broader pH and temperature ranges.

  12. Removal of hexavalent chromium ions by Yarrowia lipolytica cells modified with phyto-inspired Fe0/Fe3O4 nanoparticles

    Science.gov (United States)

    Rao, Ashit; Bankar, Ashok; Kumar, Ameeta Ravi; Gosavi, Suresh; Zinjarde, Smita

    2013-03-01

    The removal of hexavalent chromium [Cr (VI)], an important ground water pollutant by phyto-inspired Fe0/Fe3O4 nanocomposite-modified cells of Yarrowia lipolytica (NCIM 3589 and NCIM 3590), was investigated. Electron microscopy and magnetometer studies indicated an effective modification of yeast cell surfaces by the nanocomposites. The effect of pH, temperature, agitation speed, contact time and initial metal ion concentration on the removal of Cr (VI) was determined. The specific uptake values at pH 2.0 were 186.32 ± 3.17 and 137.31 ± 4.53 mg g- 1 for NCIM 3589 and NCIM 3590, respectively, when 1000 mg L- 1 of metal ion concentrations were used. The equilibrium data fitted to Scatchard, Langmuir and linearized Freundlich models suggesting that adsorption played a role in the removal of Cr (VI) ions. The surface modified yeast cells displayed higher values of Langmuir and Scatchard coefficients than the unmodified cells indicating that the former were more efficient in Cr (VI) removal. The enhanced detoxification of Cr (VI) ions by this composite material could be attributed to the reductive power of the Fe0/Fe3O4 nanocomposites as well the yeast cell surface functional groups.

  13. 不同形貌纳米Fe3O4粒子磁流体的稳定性及其流度学性能%Stability and Magneto-Rheological Properties of Magnetic Fluids Containing Fe3O4 Nano-Particles with Different Morphologies

    Institute of Scientific and Technical Information of China (English)

    胡大为; 王燕民; 潘志东

    2012-01-01

    The stability and magneto-rheological behavior of magnetic fluids containing nano-particles of Fe3O4 with irregular,octa-hedron and six-party flake morphologies as solid phase materials were investigated.A test device for the magnetic fluid stability,which was designed and manufactured based on the principle of L–C oscillator circuit,was used to determine the optimum organic modifier and surfactant concentrations for the preparation of the stable magnetic fluids.The magneto-rheological properties of the magnetic fluids with the nano-particles with different morphologies were examined in the presence of a vertical or horizontal mag-netic field.The results show that the viscosity of magnetic fluid at various shear rates in the presence of a horizontal magnetic induc-tion(i.e.,180,350 and 500 Gs) could not vary.The rheologic behaviors of the magnetic fluid became a Bingham plastic fluid in the presence of a vertical magnetic induction(i.e.,360,740 and 1 130 Gs).The viscosity and shear stress of the magnetic fluids containing the nano-particles with octahedron shape changed with the applied magnetic field.%选用无规则、正八面体和六方片状形貌的纳米Fe3O4磁性颗粒作为磁流体固相材料,通过设计组装基于L–C振荡电路的磁流体稳定性测试仪,确定制备稳定磁流体的较佳表面改性活性剂和辅助表面活性剂用量。同时,对含有不同形貌磁性颗粒的磁流体在水平方向磁场以及竖直方向磁场中的磁流变学性能进行了研究。结果表明:在外加水平方向180、350、500Gs磁感应强度,磁流体的黏度、剪切应力基本不变,磁流体表现出Newtonian流体的流变学特性;在外加竖直方向360、740、1130Gs磁感应强度,磁流体表现出Bingham流体的流变学特性;对于含有正八面体形貌纳米Fe3O4颗粒的磁流体,其黏度和剪切应力随外加磁场的变化较大。

  14. TiO2 nanoparticles supported on the Fe3O4@SiO2 nanocomposites: a novel magnetic nanocatalyst for the synthesis of 2-aminothiazoles

    International Nuclear Information System (INIS)

    Nano TiO2 supported on the Fe3O4@SiO2 nanocomposites is introduced as a novel catalyst for the environmental synthesis of 2-aminothiazoles in PEG-200 as a green medium at room temperature. In this reaction, thiourea and N-bromosuccinimide were reacted with various ketones affording the desired 2-aminothiazole compounds. This green protocol has promising features for the reaction response such as simple procedure, high yields, and the ease of separation of pure product, short reaction time, and convenient manipulation. This catalyst was easily separated by an external magnet, and the recovered catalyst was reused several times without any significant loss of activity.Graphical abstract

  15. A novel H2O2 biosensor based on Fe3O4–Au magnetic nanoparticles coated horseradish peroxidase and graphene sheets–Nafion film modified screen-printed carbon electrode

    International Nuclear Information System (INIS)

    A disposable biosensor for determination of hydrogen peroxide (H2O2) based on Fe3O4–Au magnetic nanoparticles coated horseradish peroxidase (HRP) and graphene sheets (GS)–Nafion film modified screen-printed carbon electrode (SPCE) was fabricated. To construct the H2O2 biosensor, GS–Nafion solution was first dropped onto the surface of SPCE. Subsequently, the biocomposites of Fe3O4–Au magnetic nanoparticles coated HRP were adsorbed on the surface with the aid of an external magnetic field to fabricate the SPCE|GS–Nafion/Fe3O4–Au-HRP electrode. X-ray powder diffractometer (XRD), scanning electron microscopy (SEM), electrochemical impedance spectroscopy (EIS), cyclic voltammetry (CV) and chronoamperometry(i–t curve) were employed to study the synthesis of GS, the construction processes and electrochemical properties of the biosensor. Under optimized experimental conditions, CV demonstrated that the direct electron transfer (DET) of HRP was realized. The biosensor had an excellent performance in terms of electrocatalytic reduction toward H2O2. The linear response of the biosensor to H2O2 was in the concentration range of 2.0 × 10−5 mol/L to 2.5 × 10−3 mol/L (R = 0.9994) with a detection limit of 1.2 × 10−5 mol/L (S/N = 3). The proposed electrochemical biosensor was sensitive, rapid, disposable with low cost, fewer sample volume, easy preparation and strong anti-interference, which showed great promise for screen-determination of trace H2O2 in real samples

  16. An Ultrasensitive Electrochemiluminescence Immunoassay for Carbohydrate Antigen 19-9 in Serum Based on Antibody Labeled Fe3O4 Nanoparticles as Capture Probes and Graphene/CdTe Quantum Dot Bionanoconjugates as Signal Amplifiers

    Science.gov (United States)

    Gan, Ning; Zhou, Jing; Xiong, Ping; Li, Tianhua; Jiang, Shan; Cao, Yuting; Jiang, Qianli

    2013-01-01

    The CdTe quantum dots (QDs), graphene nanocomposite (CdTe-G) and dextran–Fe3O4 magnetic nanoparticles have been synthesized for developing an ultrasensitive electrochemiluminescence (ECL) immunoassay for Carcinoembryonic antigen 19-9 (CA 19-9) in serums. Firstly, the capture probes (CA 19-9 Ab1/Fe3O4) for enriching CA 19-9 were synthesized by immobilizing the CA 19-9’s first antibody (CA 19-9 Ab1) on magnetic nanoparticles (dextran-Fe3O4). Secondly, the signal probes (CA 19-9 Ab2/CdTe-G), which can emit an ECL signal, were formed by attaching the secondary CA 19-9 antibody (CA 19-9 Ab2) to the surface of the CdTe-G. Thirdly, the above two probes were used for conjugating with a serial of CA 19-9 concentrations. Graphene can immobilize dozens of CdTe QDs on their surface, which can emit stronger ECL intensity than CdTe QDs. Based on the amplified signal, ultrasensitive antigen detection can be realized. Under the optimal conditions, the ECL signal depended linearly on the logarithm of CA 19-9 concentration from 0.005 to 100 pg/mL, and the detection limit was 0.002 pg/mL. Finally, five samples of human serum were tested, and the results were compared with a time-resolved fluorescence assay (TRFA). The novel immunoassay provides a stable, specific and highly sensitive immunoassay protocol for tumor marker detection at very low levels, which can be applied in early diagnosis of tumor. PMID:23685872

  17. An Ultrasensitive Electrochemiluminescence Immunoassay for Carbohydrate Antigen 19-9 in Serum Based on Antibody Labeled Fe3O4 Nanoparticles as Capture Probes and Graphene/CdTe Quantum Dot Bionanoconjugates as Signal Amplifiers

    Directory of Open Access Journals (Sweden)

    Ning Gan

    2013-05-01

    Full Text Available The CdTe quantum dots (QDs, graphene nanocomposite (CdTe-G and dextran–Fe3O4 magnetic nanoparticles have been synthesized for developing an ultrasensitive electrochemiluminescence (ECL immunoassay for Carcinoembryonic antigen 19-9 (CA 19-9 in serums. Firstly, the capture probes (CA 19-9 Ab1/Fe3O4 for enriching CA 19-9 were synthesized by immobilizing the CA 19-9’s first antibody (CA 19-9 Ab1 on magnetic nanoparticles (dextran-Fe3O4. Secondly, the signal probes (CA 19-9 Ab2/CdTe-G, which can emit an ECL signal, were formed by attaching the secondary CA 19-9 antibody (CA 19-9 Ab2 to the surface of the CdTe-G. Thirdly, the above two probes were used for conjugating with a serial of CA 19-9 concentrations. Graphene can immobilize dozens of CdTe QDs on their surface, which can emit stronger ECL intensity than CdTe QDs. Based on the amplified signal, ultrasensitive antigen detection can be realized. Under the optimal conditions, the ECL signal depended linearly on the logarithm of CA 19-9 concentration from 0.005 to 100 pg/mL, and the detection limit was 0.002 pg/mL. Finally, five samples of human serum were tested, and the results were compared with a time-resolved fluorescence assay (TRFA. The novel immunoassay provides a stable, specific and highly sensitive immunoassay protocol for tumor marker detection at very low levels, which can be applied in early diagnosis of tumor.

  18. Fe3O4的含量对纳米磁性导电聚苯胺电磁参数的影响%Effects of the Fe3O4 Content on the Electromagnetic Parameters of Magnetic and Conductive Polyaniline Nanoparticles

    Institute of Scientific and Technical Information of China (English)

    韩笑; 王源升

    2007-01-01

    利用乳液聚合的方法,采用十二烷基苯磺酸(DBSA)为乳化剂和掺杂剂,过硫酸铵(APS)为氧化剂合成了一种具有电磁波吸收能力的导电、导磁复合材料.TEM、SEM、FT-IR和XRD的微观结构分析表明:合成了具有核-壳包覆结构的复合材料,以磁性的Fe3O4作为内核,以DBSA掺杂的聚苯胺包覆在核外形成导电的外壳,粒径在100nm左右;利用3cm波导式测量线法研究了聚合反应中Fe3O4与苯胺的相对含量对复合材料的介电常数和磁导率的影响,分析结果表明:Fe3O4的加入能够在提高复合材料磁损耗的同时,提高其介电损耗,磁导率的虚部随着Fe3O4加入量的增多而增大,而介电常数的虚部随着Fe3O4加入量的增多先减小后增大,当Fe3O4的加入量为40%时,其磁导率虚部在4GHz处到达了最大值0.85,介电常数虚部在2GHz处达到了最大值9.62.

  19. O-羧甲基化壳聚糖修饰磁性Fe3O4纳米粒子及其生物应用%Preparation and bio application of O-caboxymethyl chitosan modified Fe3O4 magnetic nanoparticles

    Institute of Scientific and Technical Information of China (English)

    陈丽娜; 周光明; 薛莲; 刘兰; 梁莉芳; 曾献生; 盛蓉生

    2008-01-01

    采用共沉淀法制备Fe3O4纳米粒子,用XRD测定粒子成分,用透射电镜和显微镜观测粒子形貌,用震动样品磁场计测定Fe3O4粉末饱和磁化强度,再以O-羧甲基化壳聚糖修饰后,用红外光谱检测粒子成分.粒子性能良好,能很好的应用于生物分离,连接等.

  20. Poly (vinyl alcohol)/gum karaya electrospun plasma treated membrane for the removal of nanoparticles (Au, Ag, Pt, CuO and Fe3O4) from aqueous solutions

    International Nuclear Information System (INIS)

    In the present work, nanofibre membranes composed of polyvinyl alcohol (PVA) and a natural gum karaya (GK) hydrocolloid were prepared using electrospinning. The electrospun membranes of PVA/GK were cross-linked with heat treatment and later methane plasma was used to obtain a hydrophobic membrane. The morphology, characterization and adsorption ability of P-NFM was assessed using scanning electron microscopy, UV–vis spectroscopy, ATR-FTIR techniques, water contact angle and ICP-MS analytical methods. The membrane was employed for the extraction of nanoparticles (Ag, Au, Pt, CuO and Fe3O4) from water. The nanoparticle extraction kinetic and adsorption isotherm perform the pseudo-second-order model and Langmuir isotherm model, respectively. The adsorption capacities of the membrane for the removal of NPs from water diverge in the order Pt > Au > Ag > CuO > Fe3O4. The high adsorption efficiency for the removal of NPs from water was compared with an untreated membrane. Physisorption, functional group interactions, complexation reactions between metal/metal oxide nanoparticles with various functional groups present in NFM and modified surface properties such as the balance of hydrophilicity/hydrophobicity, surface free energy, and the high surface area of the plasma treated membrane were possible mechanisms of NPs adsorption onto NFM. The regeneration and reusability were tested in five consecutive adsorption/desorption cycles

  1. o-Vanillin functionalized mesoporous silica - coated magnetite nanoparticles for efficient removal of Pb(II) from water

    Science.gov (United States)

    Culita, Daniela C.; Simonescu, Claudia Maria; Patescu, Rodica-Elena; Dragne, Mioara; Stanica, Nicolae; Oprea, Ovidiu

    2016-06-01

    o-Vanillin functionalized mesoporous silica - coated magnetite (Fe3O4@MCM-41-N-oVan) was synthesized and fully characterized by X-ray diffraction, Fourier transform infrared spectroscopy, transmission electron microscopy, N2 adsorption-desorption technique and magnetic measurements. The capacity of Fe3O4@MCM-41-N-oVan to adsorb Pb(II) from aqueous solutions was evaluated in comparison with raw mesoporous silica - coated magnetite (Fe3O4@MCM-41) and amino - modified mesoporous silica coated magnetite (Fe3O4@MCM-41-NH2). The effect of adsorption process parameters such us pH, contact time, initial Pb(II) concentration was also investigated. The adsorption data were successfully fitted with the Langmuir model, exhibiting a maximum adsorption capacity of 155.71 mg/g at pH=4.4 and T=298 K. The results revealed that the adsorption rate was very high at the beginning of the adsorption process, 80-90% of the total amount of Pb(II) being removed within the first 60 min, depending on the initial concentration. The results of the present work suggest that Fe3O4@MCM-41-N-oVan is a suitable candidate for the separation of Pb(II) from contaminated water.

  2. Age Modulates Fe3O4 Nanoparticles Liver Toxicity: Dose-Dependent Decrease in Mitochondrial Respiratory Chain Complexes Activities and Coupling in Middle-Aged as Compared to Young Rats

    Directory of Open Access Journals (Sweden)

    Yosra Baratli

    2014-01-01

    Full Text Available We examined the effects of iron oxide nanoparticles (IONPs on mitochondrial respiratory chain complexes activities and mitochondrial coupling in young (3 months and middle-aged (18 months rat liver, organ largely involved in body iron detoxification. Isolated liver mitochondria were extracted using differential centrifugations. Maximal oxidative capacities (Vmax, complexes I, III, and IV activities, Vsucc (complexes II, III, and IV activities, and Vtmpd, (complex IV activity, together with mitochondrial coupling (Vmax/V0 were determined in controls conditions and after exposure to 250, 300, and 350 μg/ml Fe3O4 in young and middle-aged rats. In young liver mitochondria, exposure to IONPs did not alter mitochondrial function. In contrast, IONPs dose-dependently impaired all complexes of the mitochondrial respiratory chain in middle-aged rat liver: Vmax (from 30 ± 1.6 to 17.9 ± 1.5; P<0.001, Vsucc (from 33.9 ± 1.7 to 24.3 ± 1.0; P<0.01, Vtmpd (from 43.0 ± 1.6 to 26.3 ± 2.2 µmol O2/min/g protein; P<0.001 using Fe3O4 350 µg/ml. Mitochondrial coupling also decreased. Interestingly, 350 μg/ml Fe3O4 in the form of Fe3+ solution did not impair liver mitochondrial function in middle-aged rats. Thus, IONPs showed a specific toxicity in middle-aged rats suggesting caution when using it in old age.

  3. Sodium acetate orientated hollow magnetite nanoparticles fabrication and characterization%醋酸钠诱导的空心Fe3O4磁粒制备及表征∗

    Institute of Scientific and Technical Information of China (English)

    贺全国; 梁静; 刘军

    2015-01-01

    采用溶剂热法制备空心结构的 Fe3 O4纳米粒子,其中用乙二醇作为溶剂和还原剂、六水合三氯化铁(FeCl3•6 H2 O)作为铁离子源、无水醋酸钠(NaAc)作为碱性试剂和辅助结构指导剂,制备出了平均粒径为222 nm、空心结构明显、饱和磁强度为125.00 A•m2/kg,且具有良好反尖晶石晶型的 Fe3 O4纳米粒子.最后推测提出了空心磁粒的形成源自醋酸钠诱导的奥斯特瓦尔德(Ostwald)熟化机理.%Monodispersed magnetite (Fe3 O4 )nanospheres with hollow or porous interior structures were pre-pared via a facile one-pot solvothermal route.The simple fabrication process was characterized by using iron (Ⅲ)chloride hexahydrate (FeCl3•6 H2 O)as only ferric ion resource and anhydrous sodium acetate (NaAc)as structure-directing agent in an ethylene glycol solution without templates or surfactants involved.We prepared the hollow-structured magnetite nanoparticles with an average particle diameter of 222 nm,and saturation mag-netization intensity of 125.00 A•m2/kg,and they were inverse spinel crystal.A plausible mechanism based on sodium acetate orientation and subsequent local Ostwald ripening was proposed.

  4. 功能化纳米Fe3O4磁性材料的制备及其对水中重金属离子的去除%Heavy Metal Removal from Aqueous Solution by Functional Magnetic Fe3O4 Nanoparticles

    Institute of Scientific and Technical Information of China (English)

    谭丽莎; 孙明洋; 胡运俊; 程丽华; 徐新华

    2013-01-01

    重金属污染是目前最为严峻的环境污染问题之一.利用新颖、高效、易分离再生的功能化磁性纳米材料去除水中的重金属,已越来越受到研究者的关注.本文综述了国内外功能化纳米Fe3O4磁性材料的制备方法及其对水中重金属离子去除的研究进展,重点阐述了针对不同重金属离子去除的纳米Fe3O4磁性材料氨基化(—NH2)、巯基化(—SH)、羧基化(-COOH)及其他功能化的表面修饰材料、修饰方法及其应用,并比较了目前应用于水中重金属离子去除的功能化纳米Fe3O4磁性材料制备方法的优缺点,简要讨论了功能化纳米Fe3O4磁性材料对重金属离子去除的影响因素以及机理.最后,对功能化纳米Fe3O4磁性材料去除水中重金属离子研究的未来发展方向进行了展望.

  5. Vanillin-molecularly targeted extraction of stir bar based on magnetic field induced self-assembly of multifunctional Fe3O4@Polyaniline nanoparticles for detection of vanilla-flavor enhancers in infant milk powders.

    Science.gov (United States)

    Wu, Jinhua; Yang, Zaiyue; Chen, Ning; Zhu, Wanying; Hong, Junli; Huang, Changgao; Zhou, Xuemin

    2015-03-15

    A molecularly imprinted stir bar was constructed based on Fe3O4@Polyaniline nanoparticles with magnetic field-induced self-assembly process. The monomer, methacrylic acid, was pre-assembled into the pre-polymers with vanillin as template by the formation of hydrogen bonds. After that, the magnetic complexes were generated by the hydrogen bonding, the hydrophobic and π-π interaction between the pre-polymers and Fe3O4@Polyaniline. The complexes were adsorbed on the surface of magnetic stir bar under the magnetic induction, and the coating of vanillin-molecularly imprinted polymers was generated by the one-step copolymerization basing on the cross linking of ethylene glycol dimethacrylate. The molecular imprinting stir bar showed superior selectivity and fast binding kinetics for vanillin, and was used for the enrichment of vanilla-flavor enhancers (vanillin, ethyl maltol and methyl vanillin) in infant milk powders. The results measured by HPLC-UV exhibited good linear ranges of 0.01-100, 0.02-100 and 0.03-100μgmL(-1) with the limit of detection of 2.5-10.0ngmL(-1), and the recoveries were 94.7-98.9%, 82.1-96.7% and 84.5-93.2% with RSD<7.2% for the three enhancers, respectively. PMID:25514645

  6. Vanillin-molecularly targeted extraction of stir bar based on magnetic field induced self-assembly of multifunctional Fe3O4@Polyaniline nanoparticles for detection of vanilla-flavor enhancers in infant milk powders.

    Science.gov (United States)

    Wu, Jinhua; Yang, Zaiyue; Chen, Ning; Zhu, Wanying; Hong, Junli; Huang, Changgao; Zhou, Xuemin

    2015-03-15

    A molecularly imprinted stir bar was constructed based on Fe3O4@Polyaniline nanoparticles with magnetic field-induced self-assembly process. The monomer, methacrylic acid, was pre-assembled into the pre-polymers with vanillin as template by the formation of hydrogen bonds. After that, the magnetic complexes were generated by the hydrogen bonding, the hydrophobic and π-π interaction between the pre-polymers and Fe3O4@Polyaniline. The complexes were adsorbed on the surface of magnetic stir bar under the magnetic induction, and the coating of vanillin-molecularly imprinted polymers was generated by the one-step copolymerization basing on the cross linking of ethylene glycol dimethacrylate. The molecular imprinting stir bar showed superior selectivity and fast binding kinetics for vanillin, and was used for the enrichment of vanilla-flavor enhancers (vanillin, ethyl maltol and methyl vanillin) in infant milk powders. The results measured by HPLC-UV exhibited good linear ranges of 0.01-100, 0.02-100 and 0.03-100μgmL(-1) with the limit of detection of 2.5-10.0ngmL(-1), and the recoveries were 94.7-98.9%, 82.1-96.7% and 84.5-93.2% with RSD<7.2% for the three enhancers, respectively.

  7. Facile synthesis of new nano sorbent for magnetic solid-phase extraction by self assembling of bis-(2,4,4-trimethyl pentyl)-dithiophosphinic acid on Fe3O4-Ag core-shell nanoparticles: Characterization and application

    International Nuclear Information System (INIS)

    Graphical abstract: Self assembling of bis-(2,4,4-trimethylpentyl)-dithiophosphinic acid on Fe3O4-Ag core-shell nanoparticles and application of it for solid phase extraction of PAHs. Highlights: ► A novel sorbent for magnetic solid-phase extraction of PAHs was introduced. ► Silver was coated on Fe3O4 nanoparticles (MNPs) by reduction of AgNO3 with NaBH4. ► Bis-(2,4,4-trimethylpentyl)-dithiophosphinic acid self-assembled on silver coated MNPs. ► Size, morphology, composition and properties of the nanoparticles were characterized. ► Extraction efficiency of the sorbent was investigated by extraction of five PAHs. - Abstract: A novel sorbent for magnetic solid-phase extraction by self-assembling of organosulfur compound, (bis-(2,4,4-trimethylpentyl)-dithiophosphinic acid), onto the silver-coated Fe3O4 nanoparticles was introduced. Due to the formation of covalent bond of S-Ag, the new coating on the silver surface was very stable and showed high thermal stability (up to 320 °C). The size, morphology, composition, and properties of the prepared nanoparticles have also been characterized and determined using scanning electron microscopy (SEM), energy-dispersive X-ray analyzer (EDX), dynamic light scattering (DLS), Fourier transform-infrared (FT-IR) spectroscopy, and thermal gravimetric analysis (TGA). Extraction efficiency of the new sorbent was investigated by extraction of five polycyclic aromatic hydrocarbons (PAHs) as model compounds. The optimum extraction conditions for PAHs were obtained as of extraction time, 20 min; 50 mg sorbent from 100 mL of the sample solution, and elution with 100 μL of 1-propanol under fierce vortex for 2 min. Under the optimal conditions, the calibration curves were obtained in the range of 0.05–100 μg L−1 (R2 > 0.9980) and the LODs (S/N = 3) were obtained in the range of 0.02–0.10 μg L−1. Relative standard deviations (RSDs) for intra- and inter-day precision were 2.6–4.2% and 3.6–8.3%, respectively. In

  8. Terbium doped SnO2 nanoparticles as white emitters and SnO2:5Tb/Fe3O4 magnetic luminescent nanohybrids for hyperthermia application and biocompatibility with HeLa cancer cells.

    Science.gov (United States)

    Singh, Laishram Priyobarta; Singh, Ningthoujam Premananda; Srivastava, Sri Krishna

    2015-04-14

    SnO2:5Tb (SnO2 doped with 5 at% Tb(3+)) nanoparticles were synthesised by a polyol method and their luminescence properties at different annealing temperatures were studied. Characterization of nanomaterials was done by X-ray diffraction (XRD), Fourier transformation infrared spectroscopy (FTIR), transmission electron microscopy (TEM) and vibrating sample magnetometry (VSM). XRD studies indicate that the prepared nanoparticles were of tetragonal structures. Upon Tb(3+) ion incorporation into SnO2, Sn(4+) changes to Sn(2+) and, on annealing again at higher temperature, Sn(2+) changes to Sn(4+). The prepared nanoparticles were spherical in shape. Sn-O vibrations were found from the FTIR studies. In photoluminescence studies, the intensity of the emission peaks of Tb(3+) ions increases with the increase of annealing temperature, and emission spectra lie in the region of white emission in the CIE diagram. CCT calculations show that the SnO2:5Tb emission lies in cold white emission. Quantum yields up to 38% can be obtained for 900 °C annealed samples. SnO2:5Tb nanoparticles were well incorporated into the PVA polymer and such a material incorporated into the polymer can be used for display devices. The SnO2:5Tb/Fe3O4 nanohybrid was prepared and investigated for hyperthermia applications at different concentrations of the nanohybrid. This achieves a hyperthermia temperature (42 °C) under an AC magnetic field. The hybrid nanomaterial SnO2:5Tb/Fe3O4 was found to exhibit biocompatibility with HeLa cells (human cervical cancer cells) at concentrations up to 74% for 100 μg L(-1). Also, this nanohybrid shows green emission and thus it will be helpful in tracing magnetic nanoparticles through optical imaging in vivo and in vitro application. PMID:25747103

  9. Preparation of iron oxide nanoparticles supported on magnesium oxide for producing high-quality single-walled carbon nanotubes%用于制备优质单壁碳纳米管管束的MgO负载Fe3O4纳米粒子的合成

    Institute of Scientific and Technical Information of China (English)

    Wei-WenLiu; Azizan Aziz; Siang-PiaoChai; Abdul Rahman Mohamed; Ching-Thian Tye

    2011-01-01

    采用沉淀方法制备了直径分布狭窄的均匀Fe3O4纳米颗粒.Fe3O4纳粒形体几近一致,平均粒径为10.33 nm±2.99 nm(平均粒径±标准偏差).在超声作用下将MgO纳米颗粒分散在一定量Fe3O4纳米颗粒的水溶液中获得MgO负载Fe3O4的纳米颗粒.以甲烷为碳源,Fe3O4/MgO为催化剂,经化学气相沉积,在Fe3O4纳粒上制得了大量直径近乎均匀的单壁碳纳米管(SWCNTs)束.TEM显示:SWCNTs的平均直径1.22rm.热重分析显示:样品在400℃~600℃温度区间失重量约19%.拉曼光谱显示:SWCNTs的ID/IG的强度比为0.03,表明采用Fe3O4/MgO催化剂可制得高石墨化程度的单壁碳纳米管.%Fe3O4 nanoparticles with a narrow diameter distribution having an average diameter of 10.33 nm±2.99 nm( average diameter±standard deviation) were prepared by a precipitation method.The Fe3O4 nanoparticles were supported on MgO by mixing the MgO nanopowder with the required amount of Fe3O4 nanoparticles in water under extensive sonication.Single-walled carbon nanotubes (SWCNTs) were synthesized by the chemical vapor deposition (CVD) of methane over the Fe3O4/MgO catalyst.Transmission electron microscopy showed that a large number of SWCNT bundles of nearly uniform diameter were produced by the CVD method.The average diameter of the produced SWCNTs was ca.1.22nm.Thermogravimetric analysis showed that the weight loss was approximately 19% by oxidation of carbon in the temperature range of 400-680 ℃.The ratio of the intensity of the D-band to theG-band was 0.03,indicating that the SWCNTs were well-graphitized.

  10. Removal of methyl orange from aqueous solution by Azolla filicoloides: Synthesis of Fe3O4 nano-particles and its surface modification by the extracted pectin of Azolla

    Institute of Scientific and Technical Information of China (English)

    Roohan Rakhshaee; Masoud Giahi; Afshin Pourahmad

    2011-01-01

    The modified Fe3O4 nano-particles with the extracted pectin from the cell wall of Azolla filicoloides (FN-EP) can remove methyl orange as a water-soluble azo dye from waste water better than Azolla and the extracted pectin from Azolla (EPA), alone. It could be due to more crowding the main functional groups of uptake after binding pectin with nano-particles. Thermodynamic studies showed that adsorption equilibrium constant (KL) and maximum adsorption capacities (Qmax) were increased with decreasing temperature (exothermic). The maximum uptake capacity (Qmax) of dye by FN-EP in a batch reactor was 0.533, 0.498 and 0.446 mmol/g at 5, 25 and 50 ℃, respectively. The enthalpy change (AH) and entropy change (△S) were -15.31 kJ/mol and -0.02434 kJ/mol K, respectively.

  11. Improvement of the stability and activity of immobilized trypsin on modified Fe3O4 magnetic nanoparticles for hydrolysis of bovine serum albumin and its application in the bovine milk.

    Science.gov (United States)

    Atacan, Keziban; Çakıroğlu, Bekir; Özacar, Mahmut

    2016-12-01

    Trypsin (EC 3.4.21.4) was successfully immobilized on the surface of Fe3O4 magnetic nanoparticles that had been pre-treated with gallic acid (GA). Measurements of protein load by using Bradford assay and the trypsin-catalyzed hydrolysis of Nα-Benzoyl-dl-arginine 4-nitroanilide hydrochloride (BApNA) were made for the immobilized enzyme. By using magnetic nanoparticles, which provides easy separation and decent support material for enzyme immobilization with high surface area to volume ratio, and by employing biocompatible material gallic acid, immobilized enzyme system was synthesized along with improving trypsin activity and stability. Immobilized trypsin (TR) was more stable than the free one and demonstrated higher enzymatic activity at elevated temperatures (45-55°C) and in the alkaline pH region (6-10.5). Fe3O4 NPs-GA-TR retained 92% of its initial activity after 120days of storage at 4°C in sodium phosphate buffer (0.1M, pH 7.5), whereas the free trypsin maintained about 64% of its initial activity during the same storage period. In addition, activity of the immobilized trypsin was preserved 54.5% of its initial activity after eight times successive reuse. The Michaelis-Menten kinetic constant (Km) and maximum reaction velocity (Vmax) for free trypsin were 5.1mM and 23mM/min, respectively, whereas Km and Vmax values of immobilized trypsin were 7.88mM and 18.3mM/min, respectively. The performance of the immobilized trypsin was demonstrated by carrying out the hydrolysis of bovine serum albumin (BSA) within 1h, and the assay was performed by using liquid chromatography-mass spectrometry (LC-MS/MS) technique. The hydrolysis of bovine milk as a real food was investigated by immobilized trypsin using sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE). PMID:27374556

  12. Influence of the uniform electric field on viscosity of magnetic nanofluid (Fe3O4-EG)

    Science.gov (United States)

    Monajjemi Rarani, E.; Etesami, N.; Nasr Esfahany, M.

    2012-11-01

    Viscosity of Fe3O4/ethylene glycol nanofluids under electric field (ac and dc) was investigated experimentally. Magnetic nanofluids were prepared by dispersing Fe3O4 nanoparticles in ethylene glycol using a sonicator. Experiments showed that dilute magnetic nanofluids (fluid exhibit Newtonian behavior. Viscosity of Fe3O4 / ethylene glycol nanofluids in electric field was measured using capillary tube viscometer. Electric field decreased the viscosity of magnetic nanofluids and base fluid. The viscosity reduction was more profound in higher volume concentrations of nanoparticles. dc electric field caused greater viscosity reduction in magnetic nanofluids relative to ac electric field while ac electric field showed greater reduction effect for base liquid.

  13. p[5HRE] AFPp-p53/PEI-Fe3O4 magnetic nanoparticle combined with magnetic fluid hyperthermia inhibit hepatoma cells%p[5HRE] AFPp-p53/PEI-Fe3O4磁性纳米颗粒联合磁流体热疗对肝癌细胞的抑制作用

    Institute of Scientific and Technical Information of China (English)

    赵成桂; 袁晨燕; 吴国球

    2016-01-01

    目的:建立p[5HRE] AFPp-p53/PEI-Fe3O4磁性纳米颗粒靶向基因治疗和磁流体热疗系统用于肝癌的联合治疗,以提高治疗的安全性和有效性.方法:亚克隆基因重组法构建靶向肝癌的治疗基因p[5 HRE] AFPp-p53,并用限制性内切酶凝胶电泳法检测重组质粒是否构建成功;用共沉淀法制备磁性纳米颗粒PEI-Fe3O4,利用透射电镜、粒径仪、傅里叶转换红外光谱仪等对PEI-Fe3O4进行表征检测.MTT法检测PEI-Fe3O4转染p[HRE] AFPp-p53至不同细胞系后的细胞增殖及磁流体热疗和基因治疗联合作用对肝癌细胞HepG2的增值抑制作用.结果:成功制备载有靶向治疗基因的p[5HRE] AFPp-p53/PEI-Fe3O4磁性纳米颗粒,由其介导的基因治疗组与阴性及纳米颗粒对照组相比,明显抑制肝癌HepG2(AFP阳性)细胞[(0.592 ±0.041) vs (1.052 ±0.031)、(1.012-±0.021),P<0.01]和SMMC7721(AFP阴性)细胞(0.813 ±0.042) vs(1.073±0.032)、(1.182±0.052),P<0.01]的增殖活性,但对非肝癌细胞(L929和Lovo)增殖抑制作用无明显影响(P>0.05).基因治疗和磁流体热疗联合组与单独使用热疗组及基因治疗组相比显著增加HepG2细胞的增殖抑制率(76.11% vs 35.22%、42.92%,均P<0.01).结论:p[5HRE] AFPp-p53/PEI-Fe3O4磁性纳米颗粒对肝癌细胞具有特异性杀伤作用,并且能与磁流体热疗产生协同效应,是一种选择性高、治疗效果好的肿瘤治疗方法.

  14. Effect and intracellular uptake of pure magnetic Fe3O4 nanoparticles in the cells and organs of lung and liver

    Institute of Scientific and Technical Information of China (English)

    LIU Shi-yuan; LONG Ling; YUAN Zheng; YIN Long-ping; LIU Rui

    2009-01-01

    @@ Magnetic particles have unique features and are being used in biological and medical science such as drug targeting,diagnosis and therapy.' We have developed technologies that enable magnetic particle to be changed from microscale to nanoscale,and the latter are termed magnetic nanoparticles(MNPs).

  15. Efficient synthesis of 3,3′-bisindoles catalyzed by Fe3O4@MCM-48-OSO3H magnetic core-shell nanoparticles

    Institute of Scientific and Technical Information of China (English)

    Alireza Khorshidi; Shahab Shariati

    2015-01-01

    Magnetite nanoparticles coated with sulfuric acid-functionalized mesoporous MCM-48 were syn-thesized and used as a catalyst in three-component domino reactions of indoles, arylglyoxal mono-hydrates andN-arylenaminones to furnish the desired 3,3′-bisindoles by formation of two C–C and one C–N bonds in a smooth cascade with good yields under mild reaction conditions. The catalyst was recovered easily and maintained activity in successive runs.

  16. Crystal structures and magnetic properties of magnetite (Fe3O4)/Polyvinyl alcohol (PVA) ribbon

    Science.gov (United States)

    Ardiyanti, Harlina; Suharyadi, Edi; Kato, Takeshi; Iwata, Satoshi

    2016-04-01

    Ribbon of magnetite (Fe3O4)/Polyvinyl Alcohol (PVA) nanoparticles have been successfully fabricated with various concentration of PVA synthesized by co-precipitation method. Particle size of nanoparticles Fe3O4 sample and ribbon Fe3O4/PVA 25% sample is about 9.34 nm and 11.29 nm, respectively. The result of Vibrating Sample Magnetometer (VSM) showed that saturation magnetization value decreased from 76.99 emu/g to 15.01 emu/g and coercivity increased from 49.30 Oe to 158.35 Oe as increasing concentration of PVA. Atomic Force Microscopy (AFM) analysis showed that encapsulated PVA given decreasing agglomeration, controlled shape of nanoparticles Fe3O4 more spherical and dispersed. Surface roughness decreased with increasing concentration of PVA.

  17. Hollow superparamagnetic PLGA/Fe 3O 4 composite microspheres for lysozyme adsorption

    Science.gov (United States)

    Yang, Qi; Wu, Yao; Lan, Fang; Ma, Shaohua; Xie, Liqin; He, Bin; Gu, Zhongwei

    2014-02-01

    Uniform hollow superparamagnetic poly(lactic-co-glycolic acid) (PLGA)/Fe3O4 composite microspheres composed of an inner cavity, PLGA inner shell and Fe3O4 outer shell have been synthesized by a modified oil-in-water (O/W) emulsion-solvent evaporation method using Fe3O4 nanoparticles as a particulate emulsifier. The obtained composite microspheres with an average diameter of 2.5 μm showed excellent monodispersity and stability in aqueous medium, strong magnetic responsiveness, high magnetite content (>68%), high saturation magnetization (58 emu g-1) and high efficiency in lysozyme adsorption.

  18. A multifunctional biphasic suspension of mesoporous silica encapsulated with YVO4:Eu3+ and Fe3O4 nanoparticles: synergistic effect towards cancer therapy and imaging

    Science.gov (United States)

    Shanta Singh, N.; Kulkarni, Hrishikesh; Pradhan, Lina; Bahadur, D.

    2013-02-01

    Polyol mediated synthesized luminescent YVO4:Eu3+ nanoparticles (NPs) have been encapsulated in mesoporous silica nanoparticles (MSNs) using the sol-gel process. X-ray diffraction and Fourier transform infrared spectroscopy along with transmission electron microscopy confirm the encapsulation of the YVO4:Eu3+ NPs in the SiO2 matrix. N2 adsorption/desorption analysis confirms the mesoporous nature of the MSNs and YVO4:Eu3+-MSNs. No significant quenching of the YVO4:Eu3+ luminescence is observed for YVO4:Eu3+-MSNs. This nanocomposite has been tested as a potential drug carrier. Efficient loading of doxorubicin hydrochloride (DOX), a typical anticancer drug, is observed which reaches up to 93% in 8 mg ml-1 of YVO4:Eu3+-MSNs. pH sensitive release of DOX is observed, with 54% release for pH 4.3 and 31% in a physiological environment (pH 7.4). Both MSNs and YVO4:Eu3+-MSNs nanocomposites do not show accountable toxicity to two cell lines, i.e. HeLa and MCF-7. However, as desired, toxicity is observed when cells are incubated with DOX loaded YVO4:Eu3+-MSNs. Laser scanning confocal microscopy images confirm the uptake of the nanocomposite in both cell lines. The morphology of the cells (MCF-7) changes after incubation with DOX loaded YVO4:Eu3+-MSNs, indicating an interaction of DOX with the cells. More cytotoxicity to both cell lines with ˜90% killing is observed due to the synergistic effect of magnetic fluid hyperthermia and chemotherapy using a biphasic suspension of superparamagnetic iron oxide magnetic nanoparticles and DOX loaded YVO4:Eu3+-MSNs. In addition, an AC magnetic field triggers an enhanced drug release.

  19. A multifunctional biphasic suspension of mesoporous silica encapsulated with YVO4:Eu3+ and Fe3O4 nanoparticles: synergistic effect towards cancer therapy and imaging

    International Nuclear Information System (INIS)

    Polyol mediated synthesized luminescent YVO4:Eu3+ nanoparticles (NPs) have been encapsulated in mesoporous silica nanoparticles (MSNs) using the sol–gel process. X-ray diffraction and Fourier transform infrared spectroscopy along with transmission electron microscopy confirm the encapsulation of the YVO4:Eu3+ NPs in the SiO2 matrix. N2 adsorption/desorption analysis confirms the mesoporous nature of the MSNs and YVO4:Eu3+-MSNs. No significant quenching of the YVO4:Eu3+ luminescence is observed for YVO4:Eu3+-MSNs. This nanocomposite has been tested as a potential drug carrier. Efficient loading of doxorubicin hydrochloride (DOX), a typical anticancer drug, is observed which reaches up to 93% in 8 mg ml−1 of YVO4:Eu3+-MSNs. pH sensitive release of DOX is observed, with 54% release for pH 4.3 and 31% in a physiological environment (pH 7.4). Both MSNs and YVO4:Eu3+-MSNs nanocomposites do not show accountable toxicity to two cell lines, i.e. HeLa and MCF-7. However, as desired, toxicity is observed when cells are incubated with DOX loaded YVO4:Eu3+-MSNs. Laser scanning confocal microscopy images confirm the uptake of the nanocomposite in both cell lines. The morphology of the cells (MCF-7) changes after incubation with DOX loaded YVO4:Eu3+-MSNs, indicating an interaction of DOX with the cells. More cytotoxicity to both cell lines with ∼90% killing is observed due to the synergistic effect of magnetic fluid hyperthermia and chemotherapy using a biphasic suspension of superparamagnetic iron oxide magnetic nanoparticles and DOX loaded YVO4:Eu3+-MSNs. In addition, an AC magnetic field triggers an enhanced drug release. (paper)

  20. Double-Layer Magnetic Nanoparticle-Embedded Silica Particles for Efficient Bio-Separation.

    Directory of Open Access Journals (Sweden)

    San Kyeong

    Full Text Available Superparamagnetic Fe3O4 nanoparticles (NPs based nanomaterials have been exploited in various biotechnology fields including biomolecule separation. However, slow accumulation of Fe3O4 NPs by magnets may limit broad applications of Fe3O4 NP-based nanomaterials. In this study, we report fabrication of Fe3O4 NPs double-layered silica nanoparticles (DL MNPs with a silica core and highly packed Fe3O4 NPs layers. The DL MNPs had a superparamagnetic property and efficient accumulation kinetics under an external magnetic field. Moreover, the magnetic field-exposed DL MNPs show quantitative accumulation, whereas Fe3O4 NPs single-layered silica nanoparticles (SL MNPs and silica-coated Fe3O4 NPs produced a saturated plateau under full recovery of the NPs. DL MNPs are promising nanomaterials with great potential to separate and analyze biomolecules.

  1. Catalysis of Rice Straw Hydrolysis by the Combination of Immobilized Cellulase from Aspergillus niger on β-Cyclodextrin-Fe3O4 Nanoparticles and Ionic Liquid

    Directory of Open Access Journals (Sweden)

    Po-Jung Huang

    2015-01-01

    Full Text Available Cellulase from Aspergillus niger was immobilized onto β-cyclodextrin-conjugated magnetic particles by silanization and reductive amidation. The immobilized cellulase gained supermagnetism due to the magnetic nanoparticles. Ninety percent of cellulase was immobilized, but the activity of immobilized cellulase decreased by 10%. In this study, ionic liquid (1-butyl-3-methylimidazolium chloride was introduced into the hydrolytic process because the original reaction was a solid-solid reaction. The activity of immobilized cellulase was improved from 54.87 to 59.11 U g immobilized cellulase−1 at an ionic liquid concentration of 200 mM. Using immobilized cellulase and ionic liquid in the hydrolysis of rice straw, the initial reaction rate was increased from 1.629 to 2.739 g h−1 L−1. One of the advantages of immobilized cellulase is high reusability—it was usable for a total of 16 times in this study. Compared with free cellulase, magnetized cellulase can be recycled by magnetic field and the activity of immobilized cellulase was shown to remain at 85% of free cellulase without denaturation under a high concentration of glucose (15 g L−1. Therefore, immobilized cellulase can hydrolyze rice straw continuously compared with free cellulase. The amount of harvested glucose can be up to twentyfold higher than that from the hydrolysis by free cellulase.

  2. Acute Phase Pulmonary Responses to a Single Intratracheal Spray Instillation of Magnetite (Fe3O4) Nanoparticles in Fischer 344 Rats

    Science.gov (United States)

    Tada, Yukie; Yano, Norio; Takahashi, Hiroshi; Yuzawa, Katsuhiro; Ando, Hiroshi; Kubo, Yoshikazu; Nagasawa, Akemichi; Ogata, Akio; Nakae, Dai

    2012-01-01

    Iron nanomaterials are of considerable interest for application to nanotechnology-related fields including environmental catalysis, biomedical imaging, drug delivery and hyperthermia, because of their superparamagnetic characteristics and high catalytic abilities. However, information about potential risks of iron nanomaterials is limited. The present study assessed pulmonary responses to a single intratracheal spray instillation of triiron tetraoxide nanoparticles (magnetite) in rats. Ten-week-old male and female Fischer 344 rats (n=5/group) were exposed to a single intratracheal spray instillation of 0 (vehicle), 5.0, 15.0 or 45.0 mg/kg body weight (BW) of magnetite. After 14 days, the rats were sacrificed, and biological consequences were investigated. The lung weights of the 15.0 and 45.0 mg/kg BW male and female groups were significantly higher than those of the control groups. The lungs of treated rats showed enlargement and black patches originating from the color of magnetite. The typical histopathological changes in the lungs of the treated rats included infiltration of macrophages phagocytosing magnetite, inflammatory cell infiltration, granuloma formation and an increase of goblet cells in the bronchial epithelium. The results clearly show that instilled magnetite causes foreign body inflammatory and granulating lesions in the lung. These pulmonary responses occur in a dose-dependent manner in association with the increase in lung weight. PMID:23345925

  3. Fast identification of lipase inhibitors in oolong tea by using lipase functionalised Fe3O4 magnetic nanoparticles coupled with UPLC-MS/MS.

    Science.gov (United States)

    Zhu, Yuan-Ting; Ren, Xiao-Yun; Yuan, Li; Liu, Yi-Ming; Liang, Jian; Liao, Xun

    2015-04-15

    Oolong tea is an important member in tea family, which claims for various health benefits such as preventing obesity and improving lipid metabolism. In this work, using pancreatic lipase (PL) functionalised magnetic nanoparticles (PL-MNPs) as solid phase extraction absorbent in combination with ultra-high performance liquid chromatography-mass spectrometry (UPLC-MS), we developed a method for rapid screening and identification of lipase inhibitors from oolong tea. Three PL ligands were selectively extracted and identified as (-)-epigallocatechin-3-O-gallate (EGCG), (-)-gallocatechin-3-O-gallate (GCG) and (-)-epicatechin-3-O-gallate (ECG). Their lipase inhibitory activities were significantly higher than those non-ligands. Structure-activity analysis revealed that the presence of a galloyl moiety in the structure was required for binding to PL-MNPs, and therefore, exhibiting a strong inhibition on the enzyme. Taking advantages of the specificity in enzyme binding and the convenience of magnetic separation, this method has great potential for fast screening of lipase inhibitors from natural resources. PMID:25466054

  4. Short and long term biosorption of silica-coated iron oxide nanoparticles in heterotrophic biofilms.

    Science.gov (United States)

    Herrling, Maria P; Lackner, Susanne; Tatti, Oleg; Guthausen, Gisela; Delay, Markus; Franzreb, Matthias; Horn, Harald

    2016-02-15

    The increased application of engineered nanoparticles (ENP) in industrial processes and consumer products has raised concerns about their impact on health and environmental safety. When ENP enter the global water cycle by e.g. wastewater streams, wastewater treatment plants (WWTP) represent potential sinks for ENP. During biological WWT, the attachment of ENP to biofilms is responsible for the desired removal of ENP from the water phase avoiding their release into the aquatic environment. However, the fundamental mechanisms guiding the interactions between ENP and biofilms are not yet fully understood. Therefore, this study investigates the behavior and biosorption of inorganic ENP, here magnetic iron oxide nanoparticles coated with silica (scFe3O4-NP), with heterotrophic biofilms at different time scales. Their magnetic properties enable to follow scFe3O4-NP in the biofilm system by a magnetic susceptibility balance and magnetic resonance imaging. Biofilms were exposed to scFe3O4-NP at short contact times (5 min) in flow cells and complementary, scFe3O4-NP were introduced into a moving bed biofilm reactor (MBBR) to be observed for 27 d. Mass balances revealed that scFe3O4-NP sorbed to the biofilm within a few minutes, but that the total biosorption was rather low (3.2 μg Fe/mg TSS). scFe3O4-NP mainly sorbed to the biofilm surface inducing the detachment of outer biofilm parts starting after an exposure time of 3h in the MBBR. The biosorption depended on the exposure concentration of scFe3O4-NP, but less on the contact time. Most scFe3O4-NP exited the flow cell (up to 65%) and the MBBR (57%) via the effluent. This effect was favored by the stabilization of scFe3O4-NP in the bulk liquid by organic matter leading to a low retention capacity of the MBBR system. The results contribute to improve our understanding about the fate of ENP in environmental and in technical biofilm systems and give indications for future investigations needed. PMID:26674701

  5. Short and long term biosorption of silica-coated iron oxide nanoparticles in heterotrophic biofilms.

    Science.gov (United States)

    Herrling, Maria P; Lackner, Susanne; Tatti, Oleg; Guthausen, Gisela; Delay, Markus; Franzreb, Matthias; Horn, Harald

    2016-02-15

    The increased application of engineered nanoparticles (ENP) in industrial processes and consumer products has raised concerns about their impact on health and environmental safety. When ENP enter the global water cycle by e.g. wastewater streams, wastewater treatment plants (WWTP) represent potential sinks for ENP. During biological WWT, the attachment of ENP to biofilms is responsible for the desired removal of ENP from the water phase avoiding their release into the aquatic environment. However, the fundamental mechanisms guiding the interactions between ENP and biofilms are not yet fully understood. Therefore, this study investigates the behavior and biosorption of inorganic ENP, here magnetic iron oxide nanoparticles coated with silica (scFe3O4-NP), with heterotrophic biofilms at different time scales. Their magnetic properties enable to follow scFe3O4-NP in the biofilm system by a magnetic susceptibility balance and magnetic resonance imaging. Biofilms were exposed to scFe3O4-NP at short contact times (5 min) in flow cells and complementary, scFe3O4-NP were introduced into a moving bed biofilm reactor (MBBR) to be observed for 27 d. Mass balances revealed that scFe3O4-NP sorbed to the biofilm within a few minutes, but that the total biosorption was rather low (3.2 μg Fe/mg TSS). scFe3O4-NP mainly sorbed to the biofilm surface inducing the detachment of outer biofilm parts starting after an exposure time of 3h in the MBBR. The biosorption depended on the exposure concentration of scFe3O4-NP, but less on the contact time. Most scFe3O4-NP exited the flow cell (up to 65%) and the MBBR (57%) via the effluent. This effect was favored by the stabilization of scFe3O4-NP in the bulk liquid by organic matter leading to a low retention capacity of the MBBR system. The results contribute to improve our understanding about the fate of ENP in environmental and in technical biofilm systems and give indications for future investigations needed.

  6. Synthesis and characterization of Fe 3 O 4 @C@Ag nanocomposites and their antibacterial performance

    Science.gov (United States)

    Xia, Haiqing; Cui, Bin; Zhou, Junhong; Zhang, Lulu; Zhang, Ji; Guo, Xiaohui; Guo, Huilin

    2011-09-01

    We synthesized Fe 3O 4@C@Ag nanocomposites through a combination of solvothermal, hydrothermal, and chemical redox reactions. Characterization of the resulting samples by X-ray diffraction, Fourier-transform infrared spectroscopy, field-emission scanning and transmission electron microscopy, and magnetic measurement is reported. Compared to Fe 3O 4@Ag nanocomposites, the Fe 3O 4@C@Ag nanocomposites showed enhanced antibacterial activity. The Fe 3O 4@C@Ag nanocomposites were able to almost entirely prevent growth of Escherichia coli when the concentration of Ag nanoparticles was 10 μg/mL. Antibacterial activity of the Fe 3O 4@C@Ag nanocomposites was maintained for more than 40 h at 37 °C. The intermediate carbon layer not only protects magnetic core, but also improves the dispersion and antibacterial activity of the silver nanoparticles. The magnetic core can be used to control the specific location of the antibacterial agent (via external magnetic field) and to recycle the residual silver nanoparticles. The Fe 3O 4@C@Ag nanocomposites will have potential uses in many fields as catalysts, absorbents, and bifunctional magnetic-optical materials.

  7. Removal of Cr(VIin water by Fe3O4/IP6

    Directory of Open Access Journals (Sweden)

    CHEN Lu

    2014-12-01

    Full Text Available The preparation of functional ferroferric oxide (Fe3O4 magnetic nanoparticles is widely concerned.However,during their preparation,it is difficult to control the morphology of Fe3O4 nanoparticles and also a serious agglomeration exists,greatly restricting their applications.In present paper,an economical and ′green′ reagent-phytic acid (IP6 can form micelle in the water and then the nanoparticles can grow in a soft template.The as-prepared Fe3O4/IP6 exhibited a good stability and high dispersion.Fe3O4/IP6 can chelate with Cr (VI due to its phosphate structure.The Fe3O4/IP6 chelated with Cr (VI can be removed conveniently from water using an external magnet.Fe3O4/IP6 nanocomposites have a good adsorption capacity to Cr (VI within a short time (10 min.Additionally,the effect of pH on adsorption efficiency was studied.

  8. 溶剂热法制备纳米Fe3O4粉体%Solvothermal Synthesis of Fe3O4 Nanopowders

    Institute of Scientific and Technical Information of China (English)

    刘冰; 李晓忆; 刘文宝; 姜付义

    2013-01-01

    Fe3 O4 nanoparticles are synthesized by the thermal decomposition of FeOOH with oleic acid as surfactant and 1 -octadecene as solvent. The influence of oleic acid and FeCl3 content, reaction time on the size and morphology of Fe3O4nanocrystals are studied. The results demonstrate that both the prolonging of reaction time and the increasing of FeCl3content can enlarge the magnetite particles. By increasing the oleic acid from 13. 5 mL to 20 mL, the particle diameter first decreases and then increases. X-ray powder diffraction (XRD) and transmission electron microscopy ( TEM) are used to characterize the structure and morphology of the products. The results reveal that the prepared Fe3O4nanoparticles have an inverse spinel structure. The nanoparticles have high crystallinity, good dispersion and small average diameter can be obtained after reaction at 230 ℃ for 12 with 0. 003 mol FeCl3 and 13. 5 mL oleic acid.%通过溶剂热法,以FeOOH作为前驱体,以油酸作为表面活性剂,以十八烯为溶剂,制备了纳米Fe3O4颗粒,研究了油酸和FeCl3用量、反应时间对纳米Fe3 O4粒子的大小以及分散性的影响.结果显示,FeCl3用量的增加和反应时间的延长均可使Fe3O4粒子粒径增大,油酸用量的增加会导致Fe3O4粒子粒径先减小再增大.利用XRD、TEM等手段对所制备颗粒的结构、形貌进行了表征,结果表明,所制备的纳米Fe3O4粒子属于反尖晶石结构.FeCl3用量为0.003 mol,油酸用量为13.5 mL时(即Fe3+/油酸约为1/15),在230℃反应12 h得到结晶度较高,分散性良好,平均粒径比较小的纳米Fe3O4粒子.

  9. Biocompatible magnetite nanoparticles with varying silica-coating layer for use in biomedicine: physicochemical and magnetic properties, and cellular compatibility.

    Science.gov (United States)

    Singh, Rajendra K; Kim, Tae-Hyun; Patel, Kapil D; Knowles, Jonathan C; Kim, Hae-Won

    2012-07-01

    Magnetic nanoparticles (MNPs) are considered highly useful in therapeutic and diagnostic applications. However, MNPs require surface modification to promote dispersibility in aqueous solutions and thus biocompatibility. In this article, the authors modified MNPs with inorganic silica layer to create silica-coated magnetite nanoparticles (MNP@Si) via sol-gel process. Synthesis involves hydrolysis and condensation steps using tetraethylorthosilicate (TEOS) in methanol/ polyethylene glycol (PEG) solution and ammonia catalyst. Nanoparticles were characterized in terms of morphology, particle size, crystalline phase, chemical-bond structure, surface charge and magnetic properties: in particular, the MNP@Si size was easily tunable through alteration of the Fe(3) O(4) -to-TEOS ratio. As this ratio increased, the MNP@Si size decreased from 270 to 15 nm whilst maintaining core 12-nm MNP particle size, indicating decrease in thickness of the silica coating. All MNP@Si, in direct contrast to uncoated MNPs, showed excellent stability in aqueous solution. The particles' physicochemical and magnetic properties systematically varied with size (coating thickness), and the zeta potential diminished toward negative values, while magnetization increased as the coating thickness decreased. 15-nm MNP@Si showed excellent magnetization (about 64.1 emu/g), almost comparable to that of uncoated MNPs (70.8 emu/g). Preliminary in vitro assays confirmed that the silica layer significantly reduced cellular toxicity as assessed by increase in cell viability and reduction in reactive oxygen species production during 48 h of culture. Newly-developed MNP@Si, with a high capacity for magnetization, water-dispersibility, and diminished cell toxicity, may be potentially useful in diverse biomedical applications, including delivery of therapeutic and diagnostic biomolecules.

  10. Solid phase extraction of antidepressant drugs amitriptyline and nortriptyline from plasma samples using core-shell nanoparticles of the type Fe3O4-ZrO2-N- cetylpyridinium, and their subsequent determination by HPLC with UV detection

    International Nuclear Information System (INIS)

    The solid phase extraction (SPE) is described for preconcentration of the antidepressant drugs amitriptyline and nortriptyline prior to their determination by HPLC with UV detection. It is based on the use of water-dispersible core-shell nanoparticles (NPs) of the Fe3O4-ZrO2-N-cetylpyridinium type. The positively charged surfactant N-cetylpyridinium forms mixed aggregates with the drugs on the surface of the core-shell and thereby improves the adsorption of amitriptyline and nortriptyline through hydrophobic and/or ionic interactions. Their extraction depends on the type and amount of surfactant, sample pH, extraction time, desorption conditions, sample volume and amount of NPs that were optimized by application of experimental design. The enrichment factors are 220 and 250, respectively, for amitriptyline and nortriptyline, and the detection limits are 0.04 and 0.08 ng·mL-1. This protocol enables accurate and precise quantification of the two drugs in complex and low content samples. It was applied to the determination of the two drugs in plasma samples with relative recoveries in the range from 89 to 105 % and RSDs less than 4 %. (author)

  11. Facile synthesis of monodisperse superparamagnetic Fe3O4/PMMA composite nanospheres with high magnetization

    International Nuclear Information System (INIS)

    Monodisperse superparamagnetic Fe3O4/polymethyl methacrylate (PMMA) composite nanospheres with high saturation magnetization were successfully prepared by a facile novel miniemulsion polymerization method. The ferrofluid, MMA monomer and surfactants were co-sonicated and emulsified to form stable miniemulsion for polymerization. The samples were characterized by DLS, TEM, FTIR, XRD, TGA and VSM. The diameter of the Fe3O4/PMMA composite nanospheres by DLS was close to 90 nm with corresponding polydispersity index (PDI) as small as 0.099, which indicated that the nanospheres have excellent homogeneity in aqueous medium. The TEM results implied that the Fe3O4/PMMA composite nanospheres had a perfect core-shell structure with about 3 nm thin PMMA shells, and the core was composed of many homogeneous and closely packed Fe3O4 nanoparticles. VSM and TGA showed that the Fe3O4/PMMA composite nanospheres with at least 65% high magnetite content were superparamagnetic, and the saturation magnetization was as high as around 39 emu g-1 (total mass), which was only decreased by 17% compared with the initial bare Fe3O4 nanoparticles.

  12. Facile synthesis of monodisperse superparamagnetic Fe3O4/PMMA composite nanospheres with high magnetization

    Science.gov (United States)

    Lan, Fang; Liu, Ke-Xia; Jiang, Wen; Zeng, Xiao-Bo; Wu, Yao; Gu, Zhong-Wei

    2011-06-01

    Monodisperse superparamagnetic Fe3O4/polymethyl methacrylate (PMMA) composite nanospheres with high saturation magnetization were successfully prepared by a facile novel miniemulsion polymerization method. The ferrofluid, MMA monomer and surfactants were co-sonicated and emulsified to form stable miniemulsion for polymerization. The samples were characterized by DLS, TEM, FTIR, XRD, TGA and VSM. The diameter of the Fe3O4/PMMA composite nanospheres by DLS was close to 90 nm with corresponding polydispersity index (PDI) as small as 0.099, which indicated that the nanospheres have excellent homogeneity in aqueous medium. The TEM results implied that the Fe3O4/PMMA composite nanospheres had a perfect core-shell structure with about 3 nm thin PMMA shells, and the core was composed of many homogeneous and closely packed Fe3O4 nanoparticles. VSM and TGA showed that the Fe3O4/PMMA composite nanospheres with at least 65% high magnetite content were superparamagnetic, and the saturation magnetization was as high as around 39 emu g - 1 (total mass), which was only decreased by 17% compared with the initial bare Fe3O4 nanoparticles.

  13. Facile synthesis of monodisperse superparamagnetic Fe3O4/PMMA composite nanospheres with high magnetization.

    Science.gov (United States)

    Lan, Fang; Liu, Ke-Xia; Jiang, Wen; Zeng, Xiao-Bo; Wu, Yao; Gu, Zhong-Wei

    2011-06-01

    Monodisperse superparamagnetic Fe(3)O(4)/polymethyl methacrylate (PMMA) composite nanospheres with high saturation magnetization were successfully prepared by a facile novel miniemulsion polymerization method. The ferrofluid, MMA monomer and surfactants were co-sonicated and emulsified to form stable miniemulsion for polymerization. The samples were characterized by DLS, TEM, FTIR, XRD, TGA and VSM. The diameter of the Fe(3)O(4)/PMMA composite nanospheres by DLS was close to 90 nm with corresponding polydispersity index (PDI) as small as 0.099, which indicated that the nanospheres have excellent homogeneity in aqueous medium. The TEM results implied that the Fe(3)O(4)/PMMA composite nanospheres had a perfect core-shell structure with about 3 nm thin PMMA shells, and the core was composed of many homogeneous and closely packed Fe(3)O(4) nanoparticles. VSM and TGA showed that the Fe(3)O(4)/PMMA composite nanospheres with at least 65% high magnetite content were superparamagnetic, and the saturation magnetization was as high as around 39 emu g(-1) (total mass), which was only decreased by 17% compared with the initial bare Fe(3)O(4) nanoparticles. PMID:21454944

  14. Magnetic Control of Fe3O4 Nanomaterial for Fat Ablation in Microchannel

    Directory of Open Access Journals (Sweden)

    Ming Chang

    2015-11-01

    Full Text Available In this study, surface modification of iron (II, III oxide Fe3O4 nanoparticles by oleic acid (OA coating is investigated for the microablation of fat in a microchannel. The nanoparticles are synthesized by the co-precipitation method and then dispersed in organic solvent prior to mixing with the OA. The magnetization, agglomeration, and particle size distribution properties of the OA-coated Fe3O4 nanoparticles are characterized. The surface modification of the Fe3O4 nanoparticles reveals that upon injection into a microchannel, the lipophilicity of the OA coating influences the movement of the nanoparticles across an oil-phase barrier. The motion of the nanoparticles is controlled using an AC magnetic field to induce magnetic torque and a static gradient field to control linear translation. The fat microablation process in a microchannel is demonstrated using an oscillating driving field of less than 1200 Am−1.

  15. Novel method of room temperature ionic liquid assisted Fe3O4 nanocubes and nanoflakes synthesis

    International Nuclear Information System (INIS)

    Graphical abstract: - Highlights: • First time [Bmim][TfO] IL is used for the Fe3O4 nanoparticle synthesis. • Novel method tunes Fe3O4 nanocubes and nanoflakes forms influenced by the base and IL. • Fe3O4 oxidized topotactically into γ-Fe2O3 nanoparticles by annealing and base. • Uniform morphology with average size of 33 nm negligible superstructure are formed. • Ms values are characterized by thin layer of γ-Fe2O3 on the nanoparticle surface. - Abstract: For the first time, the nanomagnetite superparamagnetic particles are successfully synthesized by precipitation method using 1-n-butyl-3-methylimidazolium trifluoromethane sulfonate [Bmim][TfO] ionic liquid medium/surfactant. The obtained Fe3O4 particles are nanocubes and nanoflakes and this formation is influenced by the base concentration and anisotropic circumstances produced by the ionic liquid and their size varies from 20 nm to 150 × 300 nm (width × length). The synthesized magnetite nanoparticles are characterized by X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FT-IR), Raman spectroscopy, Field emission scanning electron microscopy (FE-SEM), Transmission electron microscopy (TEM) and Vibrating sample magnetometer (VSM) studies. The results show that the core of the Fe3O4 nanoparticles is surrounded by a thin layer of γ-Fe2O3 by topotactical partial oxidation, which is remarkably proceed with the subsequent calcination. The magnetite nanocubes have high saturation magnetization value and exhibit superparamagnetic hysteresis loop

  16. Magnetic composite nanofibers fabricated by electrospinning of Fe3O4/gelatin aqueous solutions

    International Nuclear Information System (INIS)

    Graphical abstract: Superparamagnetic Fe3O4/GE composite nanofibers with saturation magnetization of 12.87 emμ g−1 were prepared from gelatin aqueous solution at an elevated temperature by electrospinning. - Highlights: • Electrospinning GE aqueous solution at higher temperature. • Presenting a simple and effective technique, combining wet blending with high temperature electrospinning to prepare magnetic composite nanofibers. • Developing composite nanofibers with higher superparamagnetic properties is expected to be useful in application for the biomedical field. - Abstract: We have fabricated magnetic composite nanofibers containing superparamagnetic Fe3O4 nanoparticles by the electrospinning method. Highly dispersed Fe3O4 magnetic nanoparticles were synthesized by one-step co-precipitation of Fe2+/Fe3+ under an alkaline condition with 4 wt% poly(vinyl alcohol) (PVA) aqueous solution as the stabilizer. Gelatin (GE) was used as a polymeric matrix for fabricating the nanocomposites. The prepared Fe3O4/GE composite nanofibers were characterized by scanning electron microscopy (SEM), transmission electron microscopy (TEM) and X-ray diffraction (XRD), respectively. These composite nanofibers show uniform and continuous morphology with the Fe3O4 nanoparticles embedded in the nanofibers. By studying the magnetic properties of the Fe3O4/GE composite nanofibers, we confirm that the composite nanofibers possess superparamagnetic properties with a high saturated magnetization (Ms = 12.87 emμ g−1) at room temperature. The features of this approach for getting one-dimensional magnetic nanostructure are its simplicity, effectiveness and safety. The Fe3O4/GE nanofibers with superparamagnetic properties would be potentially applied in biomedical field

  17. Controlled synthesis and size-dependent thermal conductivity of Fe3O4 magnetic nanofluids.

    Science.gov (United States)

    Wang, Baodui; Wang, Baogang; Wei, Pengfei; Wang, Xiaobo; Lou, Wenjing

    2012-01-21

    The effect of nanoparticle size (4~44 nm) on the thermal conductivities of heat transfer oils has been systematically examined using iron oxide nanoparticles. Such Fe(3)O(4) nanoparticles were synthesized by a simple one-pot pyrolysis method. The size (16~44 nm), shape and assembly patterns of monodisperse Fe(3)O(4) nanoparticles were modulated by only controlling the amount of Fe(acac)(3). After the as-prepared Fe(3)O(4) NPs were dispersed in heat transfer oils, the prepared magnetic nanofluids exhibit higher thermal conductivity than heat transfer oils, and the enhanced values increase with a decrease in particle size. In addition, the viscosities of all nanofliuids are remarkably lower than that of the base fluid, which has been found for the first time in the nanofluid field. The promising features offer potential application in thermal energy engineering. PMID:22086086

  18. Polylactide-based polyurethane shape memory nanocomposites (Fe3O4/PLAUs) with fast magnetic responsiveness

    Science.gov (United States)

    Gu, Shu-Ying; Jin, Sheng-Peng; Gao, Xie-Feng; Mu, Jian

    2016-05-01

    Polylactide-based polyurethane shape memory nanocomposites (Fe3O4/PLAUs) with fast magnetic responsiveness are presented. For the purpose of fast response and homogeneous dispersion of magnetic nanoparticles, oleic acid was used to improve the dispersibility of Fe3O4 nanoparticles in a polymer matrix. A homogeneous distribution of Fe3O4 nanoparticles in the polymer matrix was obtained for nanocomposites with low Fe3O4 loading content. A small agglomeration was observed for nanocomposites with 6 wt% and 9 wt% loading content, leading to a small decline in the mechanical properties. PLAU and its nanocomposites have glass transition around 52 °C, which can be used as the triggering temperature. PLAU and its nanocomposites have shape fixity ratios above 99%, shape recovery ratios above 82% for the first cycle and shape recovery ratios above 91% for the second cycle. PLAU and its nanocomposites also exhibit a fast water bath or magnetic responsiveness. The magnetic recovery time decreases with an increase in the loading content of Fe3O4 nanoparticles due to an improvement in heating performance for increased weight percentage of fillers. The nanocomposites have fast responses in an alternating magnetic field and have potential application in biomedical areas such as intravascular stent.

  19. Spin-dependent transport properties of Fe3O4/MoS2/Fe3O4 junctions

    Science.gov (United States)

    Wu, Han-Chun; Coileáin, Cormac Ó.; Abid, Mourad; Mauit, Ozhet; Syrlybekov, Askar; Khalid, Abbas; Xu, Hongjun; Gatensby, Riley; Jing Wang, Jing; Liu, Huajun; Yang, Li; Duesberg, Georg S.; Zhang, Hong-Zhou; Abid, Mohamed; Shvets, Igor V.

    2015-11-01

    Magnetite is a half-metal with a high Curie temperature of 858 K, making it a promising candidate for magnetic tunnel junctions (MTJs). Yet, initial efforts to exploit its half metallic nature in Fe3O4/MgO/Fe3O4 MTJ structures have been far from promising. Finding suitable barrier layer materials, which keep the half metallic nature of Fe3O4 at the interface between Fe3O4 layers and barrier layer, is one of main challenges in this field. Two-dimensional (2D) materials may be good candidates for this purpose. Molybdenum disulfide (MoS2) is a transition metal dichalcogenide (TMD) semiconductor with distinctive electronic, optical, and catalytic properties. Here, we show based on the first principle calculations that Fe3O4 keeps a nearly fully spin polarized electron band at the interface between MoS2 and Fe3O4. We also present the first attempt to fabricate the Fe3O4/MoS2/Fe3O4 MTJs. A clear tunneling magnetoresistance (TMR) signal was observed below 200 K. Thus, our experimental and theoretical studies indicate that MoS2 can be a good barrier material for Fe3O4 based MTJs. Our calculations also indicate that junctions incorporating monolayer or bilayer MoS2 are metallic.

  20. Magnetic heating of silica-coated manganese ferrite nanoparticles

    Science.gov (United States)

    Iqbal, Yousaf; Bae, Hongsub; Rhee, Ilsu; Hong, Sungwook

    2016-07-01

    Manganese ferrite nanoparticles were synthesized using the reverse micelle method; these particles were then coated with silica. The silica-coated nanoparticles were spherical in shape, with an average diameter of 14 nm. The inverse spinel crystalline structure was observed through X-ray diffraction patterns. The coating status of silica on the surface of the nanoparticles was confirmed with a Fourier transform infrared spectrometer. The superparamagnetic properties were revealed by the zero coercive force in the hysteresis curve. Controllable heating at a fixed temperature of 42 °C was achieved by changing either the concentration of nanoparticles in the aqueous solution or the intensity of the alternating magnetic field. We found that at a fixed field strength of 5.5 kA/m, the 2.6 mg/ml sample showed a saturation temperature of 42 °C for magnetic hyperthermia. On the other hand, at a fixed concentration of 3.6 mg/ml, a field intensity of 4.57 kA/m satisfied the required temperature of 42 °C.

  1. 超声乳化法制备纳米Fe3O4磁性颗粒及壳聚糖表面改性%Preparation of Fe3 04 magnetic nanoparticles by ultrasonic emulsification and research of magnetic fluids with chitosan modification

    Institute of Scientific and Technical Information of China (English)

    季业; 邵慧萍; 郭志猛; 林涛; 杨栋华

    2011-01-01

    Fe3O4 magnetic nanopartieles were prepared by means of ultrasonic emulsification and then the Fe304 magnetic fluid was made by dispersing these particles into water with chitosan as surfactants. The influences of the molar ratio of Fe2+ to Fe3 + , ultrasonic time and the amount of chitosan on the magnetic properties of the magnetic fluid were investigated. The results show that ideal Fe3 O4 magnetic nanoparticles can be obtained under the condition that the molar ratio of Fe2 + to Fe3 + is 1: 1.5 and the reaction temperature is 70 ℃ when dropping ammonia. The prepared magnetic fluid has high specific saturation magnetization and stability when the volume of the 1% chitosan solution is 50% as large as the total volume of the mixed Fe3O4 solution and the ultrasonic time after dropping chitosan is 7.5 min, which are in favor of coating the magnetic particles with chitosan.%采用超声乳化法制备纳米Fe3O4磁性颗粒,以壳聚糖作为表面活性剂,制备具有生物亲和性的水基Fe3O4磁流体.研究了Fe2+/Fe3摩尔比、超声时间和表面活性剂用量对磁流体性能的影响.结果表明:当Fe2+/Fe3+摩尔比为1:1.5,滴加氨水时反应温度为70℃时,可制备理想纳米Fe3O4磁性颗粒;超声时间为7.5 min左右,质量分数1%的壳聚糖溶液体积占Fe3O4溶液总体积的50%时,有利于壳聚糖分子的包覆,使磁流体具有较高的比饱和磁化强度及稳定性.

  2. Magnetically Recyclable Fe3O4@His@Cu Nanocatalyst for Degradation of Azo Dyes.

    Science.gov (United States)

    Kurtan, U; Amir, Md; Baykal, A; Sözeri, H; Toprak, M S

    2016-03-01

    Fe3O4@His@Cu magnetic recyclable nanocatalyst (MRCs) was synthesized by reflux method using L-histidine as linker. The composition, structure and magnetic property of the product were characterized by X-ray powder diffraction (XRD), Scanning electron microscopy (SEM), Fourier Transform infrared spectroscopy (FT-IR) and vibrating sample magnetometry (VSM). Powder XRD, FT-IR and EDAX results confirmed that the as-synthesized products has Fe3O4 with spinel structure and Cu nanoparticles with moderate crystallinity without any other impurities. The surface of the Fe3O4@His nanocomposite was covered by tiny Cu nanoparticles. We examine the catalytic activity of Fe3O4@His@Cu MRCs for the degradation of two azo dyes, methyl orange (MO) and methylene blue (MB) as well as their mixture. The reusability of the nanocatalyst was good and sustained even after 3 cycles. Therefore this innovated Fe3O4@His@Cu MRCs has a potential to be used for purification of waste water. PMID:27455668

  3. Core-Shell Nanostructure of α-Fe2O3/Fe3O4: Synthesis and Photocatalysis for Methyl Orange

    Directory of Open Access Journals (Sweden)

    Yang Tian

    2011-01-01

    Full Text Available Fe3O4 nanoparticle was synthesized in the solution involving water and ethanol. Then, α-Fe2O3 shell was produced in situ on the surface of the Fe3O4 nanoparticle by surface oxidation in molten salts, forming α-Fe2O3/Fe3O4 core-shell nanostructure. It was showed that the magnetic properties transformed from ferromagnetism to superparamagnetism after the primary Fe3O4 nanoparticles were oxidized. Furthermore, the obtained α-Fe2O3/Fe3O4 core-shell nanoparticles were used to photocatalyse solution of methyl orange, and the results revealed that α-Fe2O3/Fe3O4 nanoparticles were more efficient than the self-prepared α-Fe2O3 nanoparticles. At the same time, the photocatalyzer was recyclable by applying an appropriate magnetic field.

  4. Microwave absorption property of aligned MWCNT/Fe3O4

    Science.gov (United States)

    Hekmatara, H.; Seifi, M.; Forooraghi, K.

    2013-11-01

    This study investigated the microwave absorption properties of magnetic modified multiwall carbon nanotubes (MWCNTs) with different alignments to the electric field (E vector) of the incident electromagnetic (EM) waves. MWCNTs were decorated with Fe3O4 nanoparticles using the wet chemical method and the resulting MWCNT/Fe3O4 was then used as a filler in a MWCNT/Fe3O4/epoxy resin composite at different weight-to-epoxy-resin ratios (2%, 5%, and 8%) with good uniformity and alignment. For each filler concentration, three samples were produced with different alignments of carbon nanotubes using the solution-casting method. For sample one, the nanotube axis (k) was parallel to the E vector of the EM wave, for sample two, k was perpendicular to E, and the third sample contained randomly oriented nanotubes. Magnetic MWCNTs were exposed to a 0.4 T magnetic field in the desired direction to achieve the desired alignment of carbon nanotubes in epoxy resin. Microwave absorption characterization of the considered ranging band (X-band) at all concentrations where the alignment of MWCNT/Fe3O4 was parallel to the incident E vector showed increased absorption. Samples with a perpendicular alignment of MWCNT/Fe3O4 to incident E had the lowest absorption. Samples containing 2 wt% and 8 wt% MWCNT/Fe3O4 aligned parallel to E and had reflection losses exceeding 14.4 dB and 23.6 dB, respectively, over a 10-11 GHz range. The 5 wt% parallel aligned MWCNT/Fe3O4 showed an absorbing peak of 27 dB and a bandwidth broadened to 1.2 GHz.

  5. Controlled synthesis and photocatalysis of sea urchin-like Fe3O4@TiO2@Ag nanocomposites

    Science.gov (United States)

    Zhao, Yilin; Tao, Chengran; Xiao, Gang; Wei, Guipeng; Li, Linghui; Liu, Changxia; Su, Haijia

    2016-02-01

    Based on the synergistic photocatalytic activities of nano-sized TiO2 and Ag, as well as the magnetic properties of Fe3O4, a sea urchin-like Fe3O4@TiO2@Ag nanocomposite (Fe3O4@TiO2@Ag NCs) is controllably synthesized with tunable cavity size, adjustable shell layer of TiO2 nanofiber, higher structural stability and larger specific surface area. Here, Fe3O4@TiO2@Ag NCs are obtained with Fe3O4 as the core and nanofiber TiO2/Fe3O4/Ag nanoheterojunctions as the shell; and Ag nanoparticles with diameter of approximately 4 nm are loaded both on TiO2 nanofibers and inside the cavities of sea urchin-like Fe3O4@TiO2 nanocomposites uniformly. Ag nanoparticles lead to the production of more photogenerated charges in the TiO2/Fe3O4/Ag heterojunction via LSPR absorption, and enhance the band-gap absorption of TiO2, while the Fe3O4 cocatalyst provides the active sites for oxygen reduction by the effective transfer of photogenerated electrons to oxygen. So the photocatalytic performance is improved due to the synergistic effect of TiO2/Fe3O4/Ag nanoheterojunctions. As photocatalysts under UV and visible irradiation, the as-synthesized nanocomposites display enhanced photocatalytic and recycling properties for the degradation of ampicillin. Moreover, they present better broad-spectrum antibiosis under visible irradiation. The enhanced photocatalytic activity and excellent chemical stability, in combination with the magnetic recyclability, makes this multifunctional nanostructure a promising candidate for antibiosis and remediation in aquatic environmental contamination in the future.Based on the synergistic photocatalytic activities of nano-sized TiO2 and Ag, as well as the magnetic properties of Fe3O4, a sea urchin-like Fe3O4@TiO2@Ag nanocomposite (Fe3O4@TiO2@Ag NCs) is controllably synthesized with tunable cavity size, adjustable shell layer of TiO2 nanofiber, higher structural stability and larger specific surface area. Here, Fe3O4@TiO2@Ag NCs are obtained with Fe3O4 as the

  6. Incorporation of Fe3O4/CNTs nanocomposite in an epoxy coating for corrosion protection of carbon steel

    Science.gov (United States)

    Pham, Gia Vu; Truc Trinh, Anh; To, Thi Xuan Hang; Duong Nguyen, Thuy; Trang Nguyen, Thu; Hoan Nguyen, Xuan

    2014-09-01

    In this study Fe3O4/CNTs composite with magnetic property was prepared by attaching magnetic nanoparticles (Fe3O4) to carbon nanotubes (CNTs) by hydrothermal method. The obtained Fe3O4/CNTs composite was characterized by Fourier transform infrared (FTIR) spectroscopy, powder x-ray diffraction and transmission electron microscopy. The Fe3O4/CNTs composite was then incorporated into an epoxy coating at concentration of 3 wt%. Corrosion protection of epoxy coating containing Fe3O4/CNTs composite was evaluated by electrochemical impedance spectroscopy and adhesion measurement. The impedance measurements show that Fe3O4/CNTs composite enhanced the corrosion protection of epoxy coating. The corrosion resistance of the carbon steel coated by epoxy coating containing Fe3O4/CNTs composite was significantly higher than that of carbon steel coated by clear epoxy coating and epoxy coating containing CNTs. FE-SEM photographs of fracture surface of coatings showed good dispersion of Fe3O4/CNTs composite in the epoxy matrix.

  7. Synthesis of talc/Fe3O4 magnetic nanocomposites using chemical co-precipitation method

    Directory of Open Access Journals (Sweden)

    Kalantari K

    2013-05-01

    Full Text Available Katayoon Kalantari,1 Mansor Bin Ahmad,1,* Kamyar Shameli,1,2,* Roshanak Khandanlou11Department of Chemistry, Universiti Putra Malaysia, Serdang, Malaysia; 2Nanotechnology and Advance Materials Department, Materials and Energy Research Center, Karaj, Alborz, Karaj, Iran*These authors contributed equally to this workAbstract: The aim of this research was to synthesize and develop a new method for the preparation of iron oxide (Fe3O4 nanoparticles on talc layers using an environmentally friendly process. The Fe3O4 magnetic nanoparticles were synthesized using the chemical co-precipitation method on the exterior surface layer of talc mineral as a solid substrate. Ferric chloride, ferrous chloride, and sodium hydroxide were used as the Fe3O4 precursor and reducing agent in talc. The talc was suspended in deionized water, and then ferrous and ferric ions were added to this solution and stirred. After the absorption of ions on the exterior surface of talc layers, the ions were reduced with sodium hydroxide. The reaction was carried out under a nonoxidizing oxygen-free environment. There were not many changes in the interlamellar space limits (d-spacing = 0.94–0.93 nm; therefore, Fe3O4 nanoparticles formed on the exterior surface of talc, with an average size of 1.95–2.59 nm in diameter. Nanoparticles were characterized using different methods, including powder X-ray diffraction, transmission electron microscopy, emission scanning electron microscopy, energy dispersive X-ray spectroscopy, and Fourier transform infrared spectroscopy. These talc/Fe3O4 nanocomposites may have potential applications in the chemical and biological industries.Keywords: nanocomposites, Fe3O4 nanoparticles, talc, powder X-ray diffraction, scanning electron microscopy

  8. Green synthesis and surface properties of Fe3O4@SA core-shell nanocomposites

    Science.gov (United States)

    Cao, Huimin; Li, Juchuan; Shen, Yuhua; Li, Shikuo; Huang, Fangzhi; Xie, Anjian

    2014-05-01

    In this paper, a one-step, economic and green approach was explored to prepare Fe3O4 nanoparticles by using L-cysteine as reducer and disperser without any inert gas protection. The Fe3O4 nanoparticles were then modified with stearic acid (SA) to form Fe3O4@SA core-shell nanocomposites. The experiment results indicate that the core-shell nanocomposites prepared could form monolayer on the water surface or films by means of Langmuir-Blodgett (LB) technology due to their hydrophobic and lipophilic properties. Also the composites exhibit paramagnetism, which make product dispersed stably in the oil medium to form magnetic fluid. Moreover, they are developed as sorbents to remove oil from water surface.

  9. Synthesis of single phase magnetite, Fe3O4 nanocrystallites using single source precursor

    Science.gov (United States)

    Disale, Sujit D.; Garje, Shivram S.

    2010-10-01

    Nanocrystalline Fe3O4 have been prepared using Fe(benzsczH)2Cl2 (where, benzsczH = benzaldehyde semicarbazone) as a single-source precursor. Fe(benzsczH)2Cl2 was characterized by elemental analyses, molar conductivity measearments, magnetic susceptibility studies, cyclic voltammetry and IR spectroscopy. The pyrolysis and solvothermal decomposition in ethylene glycol of this complex resulted in cubic phase Fe3O4 nanocrystals. These nanocrystals were characterized by powder X-ray diffraction (XRD), transmission electron microscopy (TEM), energy dispersive analysis by X-rays, IR spectroscopy and hysteresis loop. XRD shows formation of cubic phase Fe3O4 for nanocrystallites obtained by both the methods. The TEM of nanoparticles obtained by pyrolysis show cubic shape plate-like morphology with average grain size of 54 nm and the nanoparticles obtained from solvothermal decomposition route have spherical shape morphology with average grain size of 16 nm.

  10. 聚多巴胺包覆的Fe3O4去除水体中的染料%Polydopamine biopolymer coated magnetic nanoparticles for dyes removal from solution

    Institute of Scientific and Technical Information of China (English)

    李晓燕; 宋娟; 张升晓; 张媛媛; 刘军深; 徐强

    2015-01-01

    多巴胺作为海洋贝类生物分泌的粘附蛋白的模拟小分子物质,在典型的海洋环境条件下能够发生自聚合反应覆盖到不同基质上.通过多巴胺的自聚合在磁性纳米Fe3O4表面包覆一层聚合多巴胺(PDA),得到Fe3O4/PDA复合材料.材料的热重分析,磁滞回线,透射电镜,红外光谱等表明PDA包覆到了Fe3O4的表面.PDA具有丰富的酚羟基和氨基,可以通过络合、配位、氢键、π-π堆积等多种作用与其他物质结合.采用亚甲基蓝和日落黄染料作为目标物考察Fe3O4/PDA的吸附性能.研究表明,溶液pH对2种染料的吸附有显著的影响,随溶液pH的升高,阳离子染料亚甲基蓝的吸附容量显著增大,而阴离子染料日落黄吸附容量明显下降.由Langmuir吸附等温模型拟合出亚甲基蓝、日落黄的最大吸附容量分别为204.1和100.0 mg/g.动力学研究表明,这2种染料的吸附能够快速达到平衡.

  11. Reactively sputtered Fe3O4-based films for spintronics

    Institute of Scientific and Technical Information of China (English)

    Li Peng; Jin Chao; Mi Wen-Bo; Bai Hai-Li

    2013-01-01

    Half metallic polycrystalline,epitaxial Fe3O4 films and Fe3O4-based heterostructures for spintronics were fabricated by DC reactive magnetron sputtering.Large tunneling magnetoresistance was found in the polycrystalline Fe3O4 films and attributed to the insulating grain boundaries.The pinning effect of the moments at the grain boundaries leads to a significant exchange bias.Frozen interfacial/surface moments induce weak saturation of the high-field magnetoresistance.The films show a moment rotation related butterfly-shaped magnetoresistance.It was found that in the films,natural growth defects,antiphase boundaries,and magnetocrystaltine anisotropy play important roles in high-order anisotropic magnetoresistance.Spin injection from Fe3O4 films to semiconductive Si and ZnO was measured to be 45% and 28.5%,respectively.The positive magnetoresistance in the Fe3O4-based heterostructures is considered to be caused by a shift of the Fe3O4 eg ↑ band near the interface.Enhanced magnetization was observed in Fe3O4/BiFeO3 heterostructures experimentally and further proved by first principle calculations.The enhanced magnetization can be explained by spin moments of the thin BiFeO3 layer substantially reversing into a ferromagnetic arrangement under a strong coupling that is principally induced by electronic orbital reconstruction at the interface.

  12. Immobilization of Horseradish Peroxidase on NH2-Modified Magnetic Fe3O4/SiO2 Particles and Its Application in Removal of 2,4-Dichlorophenol

    Directory of Open Access Journals (Sweden)

    Qing Chang

    2014-09-01

    Full Text Available Fe3O4 nanoparticles were prepared by a co-precipitation method with the assistance of ultrasound irradiation, and then coated with silica generated by hydrolysis and condensation of tetraethoxysilane. The silica-coated Fe3O4 nanoparticles were further modified with 3-aminopropyltriethoxysilane, resulting in anchoring of primary amine groups on the surface of the particles. Horseradish peroxidase (HRP was then immobilized on the magnetic core-shell particles by using glutaraldehyde as a crosslinking agent. Immobilization conditions were optimized to obtain the highest relative activity of the immobilized enzyme. It was found the durability of the immobilized enzyme to heating and pH variation were improved in comparison with free HRP. The apparent Michaelis constants of the immobilized HRP and free HRP with substrate were compared, showing that the enzyme activity of the immobilized HRP was close to that of free HRP. The HRP immobilized particles, as an enzyme catalyst, were used to activate H2O2 for degrading 2,4-dichlorophenol. The rapid degradation of 2,4-dichlorophenol indicated that the immobilized enzyme has potential applications for removing organic pollutants.

  13. Differential Scanning Calorimetry Investigations on Polyvinylidene Fluoride - Fe3O4 Nanocomposites

    Science.gov (United States)

    Salinas, Samantha; Jones, Robert; Chipara, Dorina M.; Chipara, Mircea

    2015-03-01

    Nanocomposites of polyvinylidene fluoride (PVDF)-magnetite (Fe3O4) with various weight fractions of nanofiller (0%, 0.2 %, 0.6 %, 1.2%, 2.4 %, 5.8 %, 12 %, 23 %, and 30 %) have been obtained via melt mixing by loading PVDF with Fe3O4 particles (average size 75 nm from Nanostructured & Amorphous Materials, Inc). Thermal stability of PVDF-Fe3O4 has been investigated by TGA in nitrogen. The increase of the thermal stability of PVDF due to the loading with Fe3O4 was quantified by the shift of the temperature at which the (mass) degradation rate is maximum as a function of Fe3O4 content. The effect of the nanofiller on the crystallization of PVDF was investigated by isothermal DSC (TA Instruments, Q500). Non isothermal DSC tests, (at various heating rates ranging from 1 to 25 °C/min) have been used to locate the glass, crystallization, and melting temperatures. The dependence of the glass, crystallization, and melting temperatures on the concentration of nanoparticles is reported and analyzed in detail. The data are critically analyzed within the classical Avrami theory.

  14. Preparation and characterization of Fe3O4/Au composite particles

    Institute of Scientific and Technical Information of China (English)

    CUI; Yali; HUI; Wenli; WANG; Huirong; WANG; Lijun; CHEN; Ch

    2004-01-01

    Using Fe3O4 nano-particles as seeds, a new type of Fe3O4/Au composite particles with core/shell structure and diameter of about 170 nm was prepared by reduction of Au3+ with hydroxylamine in an aqueous solution. Particle size analyzer and transmission electron microscope were used to analyze the size distribution and microstructure of the particles in different conditions. The result showed that the magnetically responsive property and suspension stability of Fe3O4 seeds as well as reduction conditions of Au3+ to Au0 are the main factors which are crucial for obtaining a colloid of the Fe3O4/Au composite particles with uniform particle dispersion,excellent stability, homogeneity in particle sizes, and effective response to an external magnet in aqueous suspension solutions. UV-Vis analysis revealed that there is a characteristic peak of Fe3O4/Au fluid. For particles with d(0.5)=168 nm, the λmax is 625 nm.

  15. Evaluation of the antibacterial activity of Ag/Fe3O4 nanocomposites synthesized using starch.

    Science.gov (United States)

    Ghaseminezhad, Seyedeh Masumeh; Shojaosadati, Seyed Abbas

    2016-06-25

    Ag/Fe3O4 nanocomposites were successfully synthesized by a facile and cost-effective method using starch. Starch acts as both a biocompatible capping agent for Fe3O4 nanoparticles and a reducing agent for the reduction of silver ions in an alkaline medium. Samples were characterized using several analytical techniques including field emission scanning electron microscopy (SEM), transmission electron microscopy (TEM), X-ray diffraction (XRD), atomic absorption spectroscopy (AAS), and Fourier-transform infrared (FT-IR) spectroscopy. The vibrating sample magnetometer revealed that the nanocomposites were superparamagnetic. The Ag/Fe3O4 nanocomposites demonstrated a high-antibacterial activity against Escherichia coli as evaluated by means of minimum inhibitory concentration. The characteristics and antibacterial activity of the nanocomposites were significantly influenced by the concentration of silver nitrate and pH. PMID:27083838

  16. Preparation of Fe3O4Spherical Nanoporous Particles Facilitated by Polyethylene Glycol 4000

    Directory of Open Access Journals (Sweden)

    Wang Li-Li

    2009-01-01

    Full Text Available Abstract Much interest has been attracted to the magnetic materials with porous structure because of their unique properties and potential applications. In this report, Fe3O4nanoporous particles assembled from small Fe3O4nanoparticles have been prepared by thermal decomposition of iron acetylacetonate in the presence of polyethylene glycol 4000. The size of the spherical nanoporous particles is 100–200 nm. Surface area measurement shows that these Fe3O4nanoporous particles have a high surface area of 87.5 m2/g. Magnetization measurement and Mössbauer spectrum indicate that these particles are nearly superparamagnetic at room temperature. It is found that the morphology of the products is greatly influenced by polyethylene glycol concentration and the polymerization degree of polyethylene glycol. Polyethylene glycol molecules are believed to facilitate the formation of the spherical assembly.

  17. Hydrothermal growth of octahedral Fe 3O4crystals

    Institute of Scientific and Technical Information of China (English)

    Dengfeng Peng; Sadeh Beysen; Qiang Li; Jikang Jian; Yanfei Sun; Jilili Jiwuer

    2009-01-01

    This paper reports the growth of octahedral magnetic Fe3O4 particles from iron powders via a simple alkaline hydrothermal process. The chemical compositions and morphologies of the as-grown Fe3O4 particles were characterized by X-ray diffraction (XRD), X-ray photoelectron spectra (XPS), and scanning electron microscopy (SEM). Structure characterization showed that the phase structure of the prepared particles evolved from α-Fe to pure Fe3O4 with increasing concentration of KOH, indicating the important role of KOH concentration on the formation of the magnetite octahedron. The magnetic properties of samples were also studied by means of a vibrating sample magnetometer (VSM). The pure magnetite Fe3O4 octahedrons exhibited a relatively high saturation magnetization of 96.7 emu/g.

  18. Preparation and Characterization of Solvent-free Fe3O4 Nanofluids%无溶剂Fe3O4纳米流体的制备及表征

    Institute of Scientific and Technical Information of China (English)

    檀雨默; 郑亚萍; 兰岚

    2012-01-01

    采用共沉淀法合成Fe3O4纳米粒子,将含有硅氧烷基的离子型改性剂二甲基十八烷基[3-(三甲氧基硅基)丙基]氯化铵与Fe3O4纳米粒子进行接枝反应,再用脂肪醇聚氧乙烯醚磺酸盐的长链阴离子交换C1-,在Fe3O4纳米粒子表面生成具有阴、阳离子双电层结构的表面处理层,得到无溶剂Fe3O4纳米流体.研究结果表明,在Fe3O4纳米粒子表面成功接枝了有机物长链,改性的Fe3O4纳米粒子呈单分散分布,其损耗剪切模量G″明显大于储能剪切模量G',具有明显的流体行为,在室温下即可流动.%The surfactant was used to functionalize the nanoparticles to prepare solvent-free nanofluids. To prevent Fe3O4 nanoparticles from agglomerating and improve the dispersion of Fe3O4 nanoparticles, the solvent-free Fe3O4 nanofluids were synthesized through surface modification. Magnetic Fe3O4 nanoparticles were firstly prepared by chemical co-precipitation method. Then graft the quaternary ammonium salt (CH3O)3Si(CH2)3N+(CH3)2(C18Hj7)C1-, which has silanol groups, on Fe3O4 nanoparticles with hydroxyl groups. Finally, the chloridion was replaced with the anion C9H19-C6H4(OCH2CH2)200(0112)3503 through an ion-exchang process. An organic layer was formed on the surface of Fe3O4 nanoparticles, and made the Fe3O4 nanoparticles from black powder to brown fluid ( at room temperature). The solvent-free Fe3O4 nanofluids were characterized by X-ray diffraction, Fourier transform infrared spectrum, differential scanning calorimetry, thermogravimetric analysis, transmission electron microscopy and rheometer. The Fe3O4 nanoparticles were monodispersed in solvent-free nanofluids, and the content of Fe3O4 nanoparticles in the nanofluids proved to be about 12%. The loss shear modulus G" was higher than the storage shear modulus G1.

  19. Fe_3O_4/Au复合磁性纳米颗粒的制备及其表征%Preparation and characterization of Fe_3O_4/Au nano particles

    Institute of Scientific and Technical Information of China (English)

    李德才; 张少兰; 李剑玲; 崔红超

    2011-01-01

    The Fe3O4 magnetic nanoparticles were prepared by the method of chemical co-precipitation first,the effect factors of influencing the properties of magnetic nanoparticles,such as precipitator selection,the quantity of precipitator and the way of addition,aging time,quantity of surfactant and Fe2+/Fe3+ molar ratio were studied by authors.The saturation magnetization of prepared Fe3O4 magnetic nanoparticles is 73.85A·m2/kg,and the particle diameter is below 10nm.Then,the Fe3O4/Au composite nanoparticles were prepared and characterized by VSM,TEM,XRD,XPS means.The authors studied the influence of the amount of HAuCl4,the kind of reducing agent,silane coupling agent,as well as Fe3O4 nano-particles before coating Au on the properties of composite particles,the results show that the obtained Fe3O4/Au composite nanoparticles are well-coated,particle size is 50-200nm,saturation magnetization is 10.08A·m2/kg.%首先通过化学共沉淀法制备出Fe3O4磁性纳米颗粒,考察了表面活性剂的用量、碱的用量、陈化时间以及三价铁与二价铁的摩尔比等因素对Fe3O4纳米颗粒性能的影响。制备出饱和磁化强度为73.85A.m2/kg、粒径大小为10nm以下的Fe3O4纳米颗粒。在此基础上,制备出Fe3O4/Au复合纳米颗粒,通过VSM、TEM、XRD、XPS对产物进行了表征,研究了HAuCl4的用量、还原剂的种类、硅烷偶联剂以及包金之前的Fe3O4纳米颗粒对复合颗粒的影响,结果表明所制得的Fe3O4/Au复合磁性纳米颗粒包覆良好,粒径大

  20. One-step solvothermal synthesis of magnetic Fe3O4-graphite composite for Fenton-like degradation of levofloxacin.

    Science.gov (United States)

    Wang, Long; Zhao, Qi; Hou, Juan; Yan, Jin; Zhang, Fengshuang; Zhao, Jiahui; Ding, Hong; Li, Yi; Ding, Lan

    2016-01-01

    A novel Fe3O4-graphite composite was prepared, characterized, and investigated as a heterogeneous Fenton-like catalyst for the degradation of levofloxacin (LEV) in an aqueous solution. The results revealed that the Fe3O4-graphite composite exhibited excellent properties for the degradation and mineralization of LEV, achieving a nearly complete degradation of 50 mg L(-1) LEV in 15 min and 48% of total organic carbon removal in 60 min under optimal conditions. A large electronic conjugation structure exists in graphite, which may lead to the fast production of •OH radical species because of the easy reduction of Fe(III) to Fe(II). In addition, we observed that the graphite can degrade LEV in the presence of H2O2. Therefore, the synergistic results of the graphite structure and Fe3O4 magnetic nanoparticles (MNPs) may contribute to the high catalytic activity of the Fe3O4-graphite composite. Compared with pure Fe3O4 MNPs, lesser iron leaching of the Fe3O4-graphite composite was observed during the degradation of LEV. The degradation efficiency of LEV remained approximately 80% at the fifth recycling run, which indicates that the Fe3O4-graphite composite has potential applications in water treatment for removing organic pollutants.

  1. Fabrication of magnetically recyclable Fe3O4@Cu nanocomposites with high catalytic performance for the reduction of organic dyes and 4-nitrophenol

    International Nuclear Information System (INIS)

    A facile and efficient approach to synthesize Fe3O4@Cu nanocomposites using L-Lysine as a linker was developed. The morphology, composition and crystallinity of the Fe3O4@Cu nanocomposites were characterized by Fourier Transform infrared spectroscopy, transmission electron microscopy, energy-dispersive X-ray spectroscopy, and powder X-ray diffraction. In addition, the magnetic properties were determined with vibrating sample magnetometer. The surface of the Fe3O4 contained many small Cu nanoparticles with sizes of about 3 nm. It was found that the Fe3O4@Cu nanocomposites could catalyze the degradation of organic dyes. The catalytic activities of the Fe3O4@Cu nanocomposites for the reduction of nitrophenol were also studied. The Fe3O