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Sample records for fe3o4 nanoparticles effect

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

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    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

  2. Effect of Fe3O4 Magnetic Nanoparticle Concentration on the Signal of Surface Plasmon Resonance (SPR) Spectroscopy

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    Oktivina, M.; Nurrohman, D. T.; Rinto, A. N. Q. Z.; Suharyadi, E.; Abraha, K.

    2017-05-01

    Effect of Fe3O4 magnetic nanoparticle concentration on the signal of surface plasmon resonance (SPR) spectra has been successfully observed. The Fe3O4 nanoparticles with a particle size of about 10.5 ± 0.2 nm were used as active materials to increase the SPR response. X-ray diffraction (XRD) pattern showed that Fe3O4 nanoparticles have a high degree of crystallinity with spinel structure. The SPR system was successfully set up by using a glass prism coupler in a Kretschmann configuration in which gold (Au) thin film was thermally evaporated on the prism base. A green laser of wavelength 543 nm was used as light source. The angular scan in the attenuated total reflection (ATR) spectra showed a dropping intensity. Those things clearly indicated the appearance of SPR coupling phenomenon on the interface of Au thin film. The SPR spectra of fixed Au masses were also performed with same angular positions of dips. The Fe3O4 nanoparticles were deposited on gold thin film as a third layer which was synthesized via co-precipitation method. Hence, it was observed that the variation of Fe3O4 concentration affected the SPR spectra profile. The concentrations of Fe3O4 nanoparticles are 1, 3, 5, 7, 9, and 11 mg/ml which correspond to the angle shift of 0.1°, 0.3°, 0.5°, 0.7°, 0.9°, and 1.0°, respectively. The SPR angle of the dip was shifted to higher value due to change of refractive index of the medium as Fe3O4 nanoparticles concentration increases. Based on this result, we can conclude that the angle shift of SPR increases with increasing concentration of Fe3O4 nanoparticles.

  3. Physiological effects of magnetite (Fe3O4) nanoparticles on perennial ryegrass (Lolium perenne L.) and pumpkin (Cucurbita mixta) plants.

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    Wang, Huanhua; Kou, Xiaoming; Pei, Zhiguo; Xiao, John Q; Shan, Xiaoquan; Xing, Baoshan

    2011-03-01

    To date, knowledge gaps and associated uncertainties remain unaddressed on the effects of nanoparticles (NPs) on plants. This study was focused on revealing some of the physiological effects of magnetite (Fe(3)O(4)) NPs on perennial ryegrass (Lolium perenne L.) and pumpkin (Cucurbita mixta cv. white cushaw) plants under hydroponic conditions. This study for the first time reports that Fe(3)O(4) NPs often induced more oxidative stress than Fe(3)O(4) bulk particles in the ryegrass and pumpkin roots and shoots as indicated by significantly increased: (i) superoxide dismutase and catalase enzyme activities, and (ii) lipid peroxidation. However, tested Fe(3)O(4) NPs appear unable to be translocated in the ryegrass and pumpkin plants. This was supported by the following data: (i) No magnetization was detected in the shoots of either plant treated with 30, 100 and 500 mg l(-1) Fe(3)O(4) NPs; (ii) Fe K-edge X-ray absorption spectroscopic study confirmed that the coordination environment of Fe in these plant shoots was similar to that of Fe-citrate complexes, but not to that of Fe(3)O(4) NPs; and (iii) total Fe content in the ryegrass and pumpkin shoots treated with Fe(3)O(4) NPs was not significantly increased compared to that in the control shoots.

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

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    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.

  5. Removal of Lignin from aqueous solution using Fe3O4 Nanoparticles as an effective adsorbent

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    Harajyoti Mazumdar

    2015-06-01

    Full Text Available The study was carried out to find out the adsorption efficiency of lignin from paper mill waste water by using Fe3O4 magnetic nanoparticles. The physico-chemical analysis of paper mill effluent results high B.O.D value. Separations of lignin from black liquor were done by acid precipitation method and removal of lignin was done with nanoparticles. Synthesis of nanoparticles was done by co-precipitation method by mixing and stirring of FeCl3.6H2O and FeCl2.4H2O solution at 2:1 molar ratio. The nanoparticles were characterized by using U.V-Vis spectrophotometer and X-Ray Diffraction. U.V-Vis spectra show absorbance spectra at around 585 nm while XRD revealed around 10 nm sizes of Fe3O4 MNPs. The removal efficiency of lignin by Fe3O4 MNPs was investigated at different pH and contact time. Maximum adsorption of lignin onto the surface of Fe3O4 MNPs took place at pH 2.5 and 10 mins of contact time. Desorption of lignin by nanoparticles was studies by using different organic solvents.

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

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    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

    2015-08-01

    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 wüstite 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.

  7. 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

  8. Synthesis, Characterizations of Superparamagnetic Fe3O4-Ag Hybrid Nanoparticles and Their Application for Highly Effective Bacteria Inactivation.

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    Tung, Le Minh; Cong, Nguyen Xuan; Huy, Le Thanh; Lan, Nguyen Thi; Phan, Vu Ngoc; Hoa, Nguyen Quang; Vinh, Le Khanh; Thinh, Nguyen Viet; Tai, Le Thanh; Ngo, Duc-The; Mølhave, Kristian; Huy, Tran Quang; Le, Anh-Tuan

    2016-06-01

    In recent years, outbreaks of infectious diseases caused by pathogenic micro-organisms pose a serious threat to public health. In this work, Fe3O4-Ag hybrid nanoparticles were synthesized by simple chemistry method and these prepared nanoparticles were used to investigate their antibacterial properties and mechanism against methicilline-resistant Staphylococcus aureus (MRSA) pathogen. The formation of dimer-like nanostructure of Fe3O4-Ag hybrid NPs was confirmed by X-ray diffraction and High-resolution Transmission Electron Microscopy. Our biological analysis revealed that the Fe3O4-Ag hybrid NPs showed more noticeable bactericidal activity than that of plain Fe3O4 NPs and Ag-NPs. We suggest that the enhancement in bactericidal activity of Fe3O4-Ag hybrid NPs might be likely from main factors such as: (i) enhanced surface area property of hybrid nanoparticles; (ii) the high catalytic activity of Ag-NPs with good dispersion and aggregation stability due to the iron oxide magnetic carrier, and (iii) large direct physical contacts between the bacterial cell membrane and the hybrid nanoparticles. The superparamagnetic hybrid nanoparticles of iron oxide magnetic nanoparticles decorated with silver nanoparticles can be a potential candidate to effectively treat infectious MRSA pathogen with recyclable capability, targeted bactericidal delivery and minimum release into environment.

  9. Biopolymer-mediated synthesis of Fe3O4 nanoparticles and investigation of their in vitro cytotoxicity effects

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    Gholoobi, Aida; Meshkat, Zahra; Abnous, Khalil; Ghayour-Mobarhan, Majid; Ramezani, Mohammad; Homaei Shandiz, Fatemeh; Verma, K. D.; Darroudi, Majid

    2017-08-01

    Superparamagnetic iron oxide nanoparticles (SPIONs; Fe3O4) were synthesized by a ;green; co-precipitation method in aqueous starch solution as a food media. Powder X-ray diffraction (PXRD) patterns indicated that the synthesized samples were pure Fe3O4 with a spinel structure, and the coating of starch did not undergo any phase change. Fourier transform infrared (FTIR) spectra confirmed the formation of starch coated Fe3O4 nanoparticles. Field emission scanning electron microscopy (FESEM) micrographs illustrated the formation of nanoparticles in the size range of below 25 nm. Magnetic measurements revealed that the saturated magnetization of the starch-SPIONs reached 36.5 emu/g. The non-toxic effect of SPIONs concentration below 50 and 100 μg/ml was observed in the studies of in vitro cytotoxicity on normal and cancerous cell lines, respectively. The dose dependent toxicity made it a suitable candidate for various medical applications.

  10. Synergistic effect of magnetic nanoparticles of Fe3O4 with gambogic acid on apoptosis of K562 leukemia cells

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    Baoan Chen

    2009-11-01

    Full Text Available Baoan Chen1,*, Yiqiong Liang1,*, Weiwei Wu1, Jian Cheng1, Guohua Xia1, Feng Gao1, Jiahua Ding1, Chong Gao1, Zeye Shao1, Guohong Li1, Wenji Chen1, Wenlin Xu2, Xinchen Sun3, Lijie Liu4, Xiaomao Li5, Xuemei 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, Southeast University, Nanjing, People’s Republic of China; 5Department of Physics, University of Saarland, Saarbruechen, Germany; 6State Key Lab of Bioelectronics (Chien-Shiung Wu Laboratory, Southeast University, Nanjing, Peoples Republic of China; *These authors have contributed equally to this workAbstract: Gambogic acid (GA has a significant anticancer effect on a wide variety of solid tumors. Recently, many nanoparticles have been introduced as drug-delivery systems to enhance the efficiency of anticancer drug delivery. The aim of this study was to investigate the potential benefit of combination therapy with GA and magnetic nanoparticles of Fe3O4 (MNPs-Fe3O4. The proliferation of K562 cells and their cytotoxicity were evaluated by MTT assay. Cell apoptosis was observed and analyzed by microscope and flow cytometry, respectively. Furthermore, realtime polymerase chain reaction and Western blotting analyses were performed to examine gene transcription and protein expression, respectively. The results showed that MNPs-Fe3O4 dramatically enhanced GA-induced cytotoxicity and apoptosis in K562 cells. The typical morphological features of apoptosis treated with GA and MNPs-Fe3O4 were observed under an optical microscope and a fluorescence microscope, respectively. The transcription of caspase-3 and bax gene in the group treated with GA and MNPs-Fe3O4 was higher than that in the GA-alone group or MNPs-Fe3O4-alone group, but

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

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

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    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.

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

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    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

  14. Synthesis, Characterizations of Superparamagnetic Fe3O4-Ag Hybrid Nanoparticles and Their Application for Highly Effective Bacteria Inactivation

    DEFF Research Database (Denmark)

    Tung, L.M.; Cong, N.X.; Huy, L.T.

    2016-01-01

    In recent years, outbreaks of infectious diseases caused by pathogenic micro-organisms pose a serious threat to public health. In this work, Fe3O4-Ag hybrid nanoparticles were synthesized by simple chemistry method and these prepared nanoparticles were used to investigate their antibacterial...... properties and mechanism against methicilline-resistant Staphylococcus aureus (MRSA) pathogen. The formation of dimer-like nanostructure of Fe3O4-Ag hybrid NPs was confirmed by X-ray diffraction and High-resolution Transmission Electron Microscopy. Our biological analysis revealed that the Fe3O4-Ag hybrid...... NPs showed more noticeable bactericidal activity than that of plain Fe3O4 NPs and Ag-NPs. We suggest that the enhancement in bactericidal activity of Fe3O4-Ag hybrid NPs might be likely from main factors such as: (i) enhanced surface area property of hybrid nanoparticles; (ii) the high catalytic...

  15. Effect of size of Fe3O4 magnetic nanoparticles on electrochemical performance of screen printed electrode using sedimentation field-flow fractionation

    Science.gov (United States)

    Dou, Haiyang; Kim, Beom-Ju; Choi, Seong-Ho; Jung, Euo Chang; Lee, Seungho

    2014-10-01

    Fe3O4 magnetic nanoparticles (MNPs) and Fe3O4-deposited multi-walled carbon nanotubes (Fe3O4@MWCNTs) were synthesized by ultrasonic co-precipitation method. The surface and structural properties of Fe3O4 MNPs and Fe3O4@MWCNTs were characterized by X-ray diffraction, field emission transmission electron microscopy (FE-TEM), X-ray photoelectron spectroscopy, and dynamic light scattering (DLS). Sedimentation field-flow fractionation (SdFFF) was, for the first time, employed to study the influence of synthesis parameters on size distribution of Fe3O4 MNPs. A reasonable resolution for SdFFF analysis of Fe3O4 MNPs was obtained by a combination of 1,600 RPM, flow rate of 0.3 mL min-1, and Triton X-100. The results suggest that lower pH and higher reaction temperature tend to yield smaller Fe3O4 MNPs size. The size distribution of Fe3O4 MNPs obtained from SdFFF was compared with those obtained from TEM and DLS. Also the effect of the particle size of Fe3O4 MNPs on electrochemical property of Fe3O4@MWCNTs-treated screen printed electrode (SPE) was studied. Cyclic voltammetry revealed that SPE treated with MWCNTs yields a significantly enhanced signal than that with no treatment. The SPE signal was even further enhanced with addition of Fe3O4 MNPs. For SPE analysis of dopamine, a liner range of 0.005-0.1 mM with a correlation coefficient of 0.986 was observed. Results revealed that (1) SdFFF is a useful tool for size-based separation and characterization of MNPs; (2) Proposed methods for synthesis of Fe3O4 nanoparticles and Fe3O4@MWCNTs are mild and fast (about 30 min); (3) SPE treated with Fe3O4@MWCNTs shows potential applicability for biosensing.

  16. 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.

  17. 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+.

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

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    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.

  19. 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.

  20. Surface Organic Modification of Fe3O4 Magnetic Nanoparticles

    Institute of Scientific and Technical Information of China (English)

    CUI Sheng; SHEN Xiaodong; LIN Benlan; JIANG Guodong; ZHANG Weihua

    2008-01-01

    The surface organic modification of Fe3O4 nanoparticles with silane coupling reagent KH570 was studied.The modified and unmodified nanoparticles were characterized by FT-IR,XPS and TEM.The spectra of FT-IR and XPS revealed that KH570 was coated onto the surface of Fe3O4 nanoparticles to get Fe-O-Si bond and an organic coating layer also was formed.Fe3O4 nanoparticles were spheres partly with mean size of 18.8 nm studied by TEM,which was consistent with the result 17.9 nm calculated by Scherrer'S equation.KH570 was adsorbed on surface and formed chemistry bond to be steric hindrance repulsion which prevented nanoparticles from reuniting.Then glycol-based Fe3O4 magnetic liquids dispersed stably was gained.

  1. 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.

  2. Effective capture and release of circulating tumor cells using core-shell Fe3O4@MnO2 nanoparticles

    Science.gov (United States)

    Xiao, Liang; He, Zhao-Bo; Cai, Bo; Rao, Lang; Cheng, Long; Liu, Wei; Guo, Shi-Shang; Zhao, Xing-Zhong

    2017-01-01

    Circulating tumor cells (CTCs) have been believed to hold significant insights for cancer diagnosis and therapy. Here, we developed a simple and effective method to capture and release viable CTCs using core-shell Fe3O4@MnO2 nanoparticles. Fe3O4@MnO2 nanoparticles bioconjugated with anti-EpCAM antibody have characteristics of specific recognition, magnetic-driven cell isolation and oxalic acid-assisted cell release. The capture and release efficiency of target cancer cells were ∼83% and ∼55%, respectively. And ∼70% of released cells kept good viability, which could facilitate the subsequent cellular analysis.

  3. Effects of coating molecules on the magnetic heating properties of Au-Fe3O4 heterodimer nanoparticles

    Science.gov (United States)

    Yamamoto, Y.; Ogasawara, J.; Himukai, H.; Itoh, T.

    2016-10-01

    In this paper, we report the heating properties of gold-magnetite (Au-Fe3O4) heterodimer nanoparticles (NPs) subjected to an alternating magnetic field. The Au-Fe3O4 NPs coated with oleic acid and oleylamine (OA) were synthesized through a method that combines seed mediation and high-temperature decomposition. The coating was replaced with dimercaptosuccinic acid (DMSA) by the ligand-exchange method. The specific absorption rates (SARs) for the OA- and DMSA-coated Au-Fe3O4 NPs coated with OA and DMSA at room temperature were determined through the calorimetric and magnetometric methods. SAR depended on the square of the magnetic field H up to an H value of 4 kA/m. The absolute value of the SAR for DMSA-coated NPs is about fivefold higher than that of the OA-coated NPs. The AC magnetic hysteresis measurements showed the recovery of the magnetic volume and the decrease in the magnetic anisotropy of the DMSA-coated NPs relative to those of the OA-coated NPs. These results suggest that the protective agent influences the magnetic properties of magnetite NPs via gold NPs.

  4. Composites of nanotubular polyaniline containing Fe3O4 nanoparticles

    Institute of Scientific and Technical Information of China (English)

    龙云泽; 陈兆甲; 刘振兴; 张志明; 万梅香; 王楠林

    2003-01-01

    Results of charge-transport and magnetic measurements of nanotubular polyaniline (PANI) composites containing Fe3O4 nanoparticles (~10nm) synthesized by a "template-free" method are reported. The T-1/2 resistivity has been observed, and dc magnetic susceptibility data are fitted to an equation X = X* p + C/T. With increasing weight ratio of Fe3O4, the electrical conductivity and temperature-independent susceptibility X* p increase, and the Curietype susceptibility is suppressed at low temperatures. Further discussions have been given. The PANI-H3PO4/Fe3O4composite containing 27wt% of Fe3O4 nanoparticles is superparamagnetic, exhibiting very little hysteresis even at 5K.

  5. Composites of nanotubular polyaniline containing Fe3O4 nanoparticles

    Institute of Scientific and Technical Information of China (English)

    LongYun-Ze; ChenZhao-Jia; LiuZhen-Xing; ZhangZhi-Ming; WanMei-Xiang; WangNan-Lin

    2003-01-01

    Results of charge-transport and magnetic measurements of nanotubular polyaniline (PANI) composites containing Fe3O4 nanoparticles (-10nm) synthesized by a “template-free” method are reported. The T-1/2 resistivity has been observed, and dc magnetic susceptibility data are fitted to an equation χ=χP*+C/T. With increasing weight ratio of Fe3O4, the electrical conductivity and temperature-independent susceptibility χP* increase, and the Curietype susceptibility is suppressed at low temperatures. Further discussions have been given. The PANI-H3PO4/Fe3O4 composite containing 27wt% of Fe3O4 nanoparticles is superparamagnetic, exhibiting very little hysteresis even at 5K.

  6. 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.

  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. Magnetic Fe3O4 nanoparticles induced effects on performance and microbial community of activated sludge from a sequencing batch reactor under long-term exposure.

    Science.gov (United States)

    Ma, Bingrui; Wang, Sen; Li, Zhiwei; Gao, Mengchun; Li, Shanshan; Guo, Liang; She, Zonglian; Zhao, Yangguo; Zheng, Dong; Jin, Chunji; Wang, Xuejiao; Gao, Feng

    2017-02-01

    The performance and microbial community of activated sludge from a sequencing batch reactor (SBR) were investigated under long-term exposure of magnetic Fe3O4 nanoparticles (Fe3O4 NPs). The COD removal showed a slight decrease at 5-60mg/L Fe3O4 NPs compared to 0mg/L Fe3O4 NPs, whereas the NH4(+)-N removal had no obvious variation at 0-60mg/L Fe3O4 NPs. It was found that 10-60mg/L Fe3O4 NPs improved the denitrification process and phosphorus removal of activated sludge. The microbial enzymatic activities of activated sludge could be affected by Fe3O4 NPs, which had similar variation trends to the nitrogen and phosphorus removal rates of activated sludge. The reactive oxygen species (ROS) production and lactate dehydrogenase (LDH) release demonstrated that Fe3O4 NPs led to the toxicity to activated sludge and destroyed the integrity of microbial cytomembrane. High throughput sequencing indicated that Fe3O4 NPs could obviously affect the microbial richness and diversity of activated sludge.

  9. Large tunneling magnetoresistance in octahedral Fe3O4 nanoparticles

    OpenAIRE

    Arijit Mitra; Barun Barick; Jeotikanta Mohapatra; Sharma, H.; Meena, S. S.; ASLAM, M.

    2016-01-01

    We have observed large tunneling Magnetoresistance (TMR) in amine functionalized octahedral nanoparticle assemblies. Amine monolayer on the surface of nanoparticles acts as an insulating barrier between the semimetal Fe3O4 nanoparticles and provides multiple tunnel junctions where inter-granular tunneling is plausible. The tunneling magnetoresistance recorded at room temperature is 38% which increases to 69% at 180 K. When the temperature drops below 150 K, coulomb staircase is observed in th...

  10. 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

  11. 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.

  12. 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.

  13. The effect of surface charge of functionalized Fe3O4 nanoparticles on protein adsorption and cell uptake.

    Science.gov (United States)

    Calatayud, M Pilar; Sanz, Beatriz; Raffa, Vittoria; Riggio, Cristina; Ibarra, M Ricardo; Goya, Gerardo F

    2014-08-01

    Nanoparticles engineered for biomedical applications are meant to be in contact with protein-rich physiological fluids. These proteins are usually adsorbed onto the nanoparticle's surface, forming a swaddling layer that has been described as a 'protein corona', the nature of which is expected to influence not only the physicochemical properties of the particles but also the internalization into a given cell type. We have investigated the process of protein adsorption onto different magnetic nanoparticles (MNPs) when immersed in cell culture medium, and how these changes affect the cellular uptake. The role of the MNPs surface charge has been assessed by synthesizing two colloids with the same hydrodynamic size and opposite surface charge: magnetite (Fe3O4) cores of 25-30 nm were in situ functionalized 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 increase of the hydrodynamic size. After 24 h of incubation large MNP-protein aggregates with hydrodynamic sizes of ≈1500 nm (PAA-MNPs) and ≈3000 nm (PEI-MNPs) were observed, each one containing an estimated number of magnetic cores between 450 and 1000. These results are consistent with the formation of large protein-MNPs aggregate units having a 'plum pudding' structure of MNPs embedded into a protein network that results in a negative surface charge, irrespective of the MNP-core charge. In spite of the similar negative ζ-potential for both MNPs within cell culture, we demonstrated that PEI-MNPs are incorporated in much larger amounts than the PAA-MNPs units. Quantitative analysis showed that SH-SY5Y cells can incorporate 100% of the added PEI-MNPs up to ≈100 pg/cell, whereas for PAA-MNPs the uptake was less than 50%. The final cellular distribution showed also notable differences regarding partial attachment to the cell membrane. These results

  14. Preparation of surface plasmon resonance biosensor based on magnetic core/shell Fe3O4/SiO2 and Fe3O4/Ag/SiO2 nanoparticles.

    Science.gov (United States)

    Wang, Liying; Sun, Ying; Wang, Jing; Wang, Jian; Yu, Aimin; Zhang, Hanqi; Song, Daqian

    2011-06-01

    In this paper, surface plasmon resonance biosensors based on magnetic core/shell Fe(3)O(4)/SiO(2) and Fe(3)O(4)/Ag/SiO(2) nanoparticles were developed for immunoassay. With Fe(3)O(4) and Fe(3)O(4)/Ag nanoparticles being used as seeding materials, Fe(3)O(4)/SiO(2) and Fe(3)O(4)/Ag/SiO(2) nanoparticles were formed by hydrolysis of tetraethyl orthosilicate. The aldehyde group functionalized magnetic nanoparticles provide organic functionality for bioconjugation. The products were characterized by scanning electronic microscopy (SEM), transmission electronic microscopy (TEM), FTIR and UV-vis absorption spectrometry. The magnetic nanoparticles possess the unique superparamagnetism property, exceptional optical properties and good compatibilities, and could be used as immobilization matrix for goat anti-rabbit IgG. The magnetic nanoparticles can be easily immobilized on the surface of SPR biosensor chip by a magnetic pillar. The effects of Fe(3)O(4)/SiO(2) and Fe(3)O(4)/Ag/SiO(2) nanoparticles on the sensitivity of SPR biosensors were also investigated. As a result, the SPR biosensors based on Fe(3)O(4)/SiO(2) nanoparticles and Fe(3)O(4)/Ag/SiO(2) nanoparticles exhibit a response for rabbit IgG in the concentration range of 1.25-20.00 μg ml(-1) and 0.30-20.00 μg ml(-1), respectively.

  15. Large tunneling magnetoresistance in octahedral Fe3O4 nanoparticles

    Directory of Open Access Journals (Sweden)

    Arijit Mitra

    2016-05-01

    Full Text Available We have observed large tunneling Magnetoresistance (TMR in amine functionalized octahedral nanoparticle assemblies. Amine monolayer on the surface of nanoparticles acts as an insulating barrier between the semimetal Fe3O4 nanoparticles and provides multiple tunnel junctions where inter-granular tunneling is plausible. The tunneling magnetoresistance recorded at room temperature is 38% which increases to 69% at 180 K. When the temperature drops below 150 K, coulomb staircase is observed in the current versus voltage characteristics as the charging energy exceeds the thermal energy. A similar study is also carried out with spherical nanoparticles. A 24% TMR is recorded at room temperature which increases to 41% at 180 K for spherical particles. Mössbauer spectra reveal better stoichiometry for octahedral particles which is attainable due to lesser surface disorder and strong amine coupling at the facets of octahedral Fe3O4 nanoparticles. Less stoichiometric defect in octahedral nanoparticles leads to a higher value of spin polarization and therefore larger TMR in octahedral nanoparticles.

  16. 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

  17. Biogenic synthesis of Fe3O4 magnetic nanoparticles using Pisum sativum peels extract and its effect on magnetic and Methyl orange dye degradation studies

    Science.gov (United States)

    Prasad, Cheera; Yuvaraja, Gutha; Venkateswarlu, Ponneri

    2017-02-01

    We have been developed facile and ecofriendly method for the synthesis of Fe3O4 magnetic nanoparticles (MNPs) using an aqueous extract of Pisum sativum peels (PS) is used as reducing and capping agent. The as synthesized PS-Fe3O4 MNPs are characterized by diverse techniques such as FTIR, powder XRD, TEM, BET and Raman spectroscopy measurements. The results show that the obtained Fe3O4 nanoparticles exhibits high specific surface area (∼17.6 m2/g) and agglomerated spherical in shape with the size range of 20-30 nm. The magnetic properties of PS-Fe3O4 MNPs sample clearly exhibits ferromagnetic nature with a saturation magnetization of 64.2 emu/g. Further, the catalytic properties of PS-Fe3O4 MNPs for degradation of Methyl orange (MO) dye in aqueous solution have been investigated by UV-visible spectroscopy. The results show that PS-Fe3O4 MNPs is an efficient catalyst for degradation of Methyl orange dye than previously reported ones.

  18. 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.

  19. Electrochemical sensing behaviour of Ni doped Fe3O4 nanoparticles

    Science.gov (United States)

    Suresh, R.; Giribabu, K.; Manigandan, R.; Vijayalakshmi, L.; Stephen, A.; Narayanan, V.

    2014-01-01

    Ni doped Fe3O4 nanoparticles were synthesized by simple hydrothermal method. The prepared nanomaterials were characterized by X-ray diffraction analysis, DRS-UV-Visible spectroscopy and field emission scanning electron microscopy. The XRD confirms the phase purity of the synthesized Ni doped Fe3O4 nanoparticles. The optical property of Ni doped Fe3O4 nanoparticles were studied by DRS UV-Visible analysis. The electrochemical sensing property of pure and Ni doped Fe3O4 nanoparticles were examined using uric acid as an analyte. The obtained results indicated that the Ni doped Fe3O4 nanoparticles exhibited higher electrocatalytic activity towards uric acid.

  20. Structural and magnetic properties of core-shell Au/Fe3O4 nanoparticles

    Science.gov (United States)

    León Félix, L.; Coaquira, J. A. H.; Martínez, M. A. R.; Goya, G. F.; Mantilla, J.; Sousa, M. H.; Valladares, L. De Los Santos; Barnes, C. H. W.; Morais, P. C.

    2017-02-01

    We present a systematic study of core-shell Au/Fe3O4 nanoparticles produced by thermal decomposition under mild conditions. The morphology and crystal structure of the nanoparticles revealed the presence of Au core of d = (6.9 ± 1.0) nm surrounded by Fe3O4 shell with a thickness of ~3.5 nm, epitaxially grown onto the Au core surface. The Au/Fe3O4 core-shell structure was demonstrated by high angle annular dark field scanning transmission electron microscopy analysis. The magnetite shell grown on top of the Au nanoparticle displayed a thermal blocking state at temperatures below TB = 59 K and a relaxed state well above TB. Remarkably, an exchange bias effect was observed when cooling down the samples below room temperature under an external magnetic field. Moreover, the exchange bias field (HEX) started to appear at T~40 K and its value increased by decreasing the temperature. This effect has been assigned to the interaction of spins located in the magnetically disordered regions (in the inner and outer surface of the Fe3O4 shell) and spins located in the ordered region of the Fe3O4 shell.

  1. Production of nearly monodisperse Fe3O4 and Fe@Fe3O4 nanoparticles in aqueous medium and their surface modification for biomedical applications

    Science.gov (United States)

    Tegafaw, Tirusew; Xu, Wenlong; Lee, Sang Hyup; Chae, Kwon Seok; Chang, Yongmin; Lee, Gang Ho

    2017-02-01

    Iron (Fe)-based nanoparticles are extremely valuable in biomedical applications owing to their low toxicity and high magnetization values at room temperature. In this study, we synthesized nearly monodisperse iron oxide (Fe3O4) and Fe@Fe3O4 (core: Fe, shell: Fe3O4) nanoparticles in aqueous medium under argon flow and then, coated them with various biocompatible ligands and silica. In this study, eight types of surface-modified nanoparticles were investigated, namely, Fe3O4@PAA (PAA = polyacrylic acid; Mw of PAA = 5100 amu and 15,000 amu), Fe3O4@PAA-FA (FA = folic acid; Mw of PAA = 5100 amu and 15,000 amu), Fe3O4@PEI-fluorescein (PEI = polyethylenimine; Mw of PEI = 1300 amu), Fe@Fe3O4@PEI (Mw of PEI = 10,000 amu), Fe3O4@SiO2 and Fe@Fe3O4@SiO2 nanoparticles. We characterized the prepared surface-modified nanoparticles using high-resolution transmission electron microscopy (HRTEM), X-ray diffraction (XRD), Fourier transform infrared (FT-IR) absorption spectroscopy, a superconducting quantum interference device (SQUID), X-ray photoelectron spectroscopy (XPS), photoluminescence (PL) spectroscopy and confocal microscopy. Finally, we measured the cytotoxicity of the samples. The results indicate that the surface-modified nanoparticles are biocompatible and are potential candidates for various biomedical applications.

  2. Magnetic nanoparticles of Fe3O4 enhance docetaxel-induced prostate cancer cell death

    Directory of Open Access Journals (Sweden)

    Sato A

    2013-08-01

    Full Text Available Akiko Sato,1 Naoki Itcho,1 Hitoshi Ishiguro,2,3 Daiki Okamoto,1 Naohito Kobayashi,4 Kazuaki Kawai,5 Hiroshi Kasai,5 Daisuke Kurioka,1 Hiroji Uemura,2 Yoshinobu Kubota,2 Masatoshi Watanabe11Laboratory for Medical Engineering, Division of Materials Science and Chemical Engineering, Graduate School of Engineering, Yokohama National University, Yokohama, Japan; 2Department of Urology, Yokohama City University Graduate School of Medicine, Yokohama, Japan; 3Photocatalyst Group, Kanagawa Academy of Science and Technology, Kawasaki, Japan; 4Department of Molecular Pathology, Yokohama City University Graduate School of Medicine, Yokohama, Japan; 5Department of Environmental Oncology, Institute of Industrial Ecological Sciences, University of Occupational and Environmental Health, Kitakyushu, JapanAbstract: Docetaxel (DTX is one of the most important anticancer drugs; however, the severity of its adverse effects detracts from its practical use in the clinic. Magnetic nanoparticles of Fe3O4 (MgNPs-Fe3O4 can enhance the delivery and efficacy of anticancer drugs. We investigated the effects of MgNPs-Fe3O4 or DTX alone, and in combination with prostate cancer cell growth in vitro, as well as with the mechanism underlying the cytotoxic effects. MgNPs-Fe3O4 caused dose-dependent increases in reactive oxygen species levels in DU145, PC-3, and LNCaP cells; 8-hydroxydeoxyguanosine levels were also elevated. MgNPs-Fe3O4 alone reduced the viability of LNCaP and PC-3 cells; however, MgNPs-Fe3O4 enhanced the cytotoxic effect of a low dose of DTX in all three cell lines. MgNPs-Fe3O4 also augmented the percentage of DU145 cells undergoing apoptosis following treatment with low dose DTX. Expression of nuclear transcription factor κB in DU145 was not affected by MgNPs-Fe3O4 or DTX alone; however, combined treatment suppressed nuclear transcription factor κB expression. These findings offer the possibility that MgNPs-Fe3O4–low dose DTX combination therapy may be

  3. 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.

  4. Electrochemical sensing property of Mn doped Fe3O4 nanoparticles

    Science.gov (United States)

    Suresh, R.; Giribabu, K.; Manigandan, R.; Vijayalakshmi, L.; Stephen, A.; Narayanan, V.

    2013-02-01

    The Mn doped Fe3O4 nanoparticles were synthesized by hydrothermal method. The prepared nanoparticles were characterized by X-ray diffraction (XRD) analysis, UV-Visible spectroscopy (UV-Vis) and field emission scanning electron microscopy (FE-SEM). The electrochemical sensing property of pure and Mn doped Fe3O4 nanoparticles were examined using uric acid (UA) as an analyte. The obtained results indicated that the Mn doped Fe3O4 nanoparticles exhibited higher electrocatalytic activity towards UA.

  5. Green synthesis of soya bean sprouts-mediated superparamagnetic Fe 3O 4 nanoparticles

    Science.gov (United States)

    Cai, Yan; Shen, Yuhua; Xie, Anjian; Li, Shikuo; Wang, Xiufang

    2010-10-01

    Superparamagnetic Fe 3O 4 nanoparticles were first synthesized via soya bean sprouts (SBS) templates under ambient temperature and normal atmosphere. The reaction process was simple, eco-friendly, and convenient to handle. The morphology and crystalline phase of the nanoparticles were determined from scanning electron microscopy (SEM), transmission electron microscopy (TEM), selected area electron diffraction (SAED), and X-ray diffraction (XRD) spectra. The effect of SBS template on the formation of Fe 3O 4 nanoparticles was investigated using X-ray photoemission spectroscopy (XPS) and Fourier-transform infrared spectroscopy (FT-IR). The results indicate that spherical Fe 3O 4 nanoparticles with an average diameter of 8 nm simultaneously formed on the epidermal surface and the interior stem wall of SBS. The SBS are responsible for size and morphology control during the whole formation of Fe 3O 4 nanoparticles. In addition, the superconducting quantum interference device (SQUID) results indicate the products are superparamagnetic at room temperature, with blocking temperature ( TB) of 150 K and saturation magnetization of 37.1 emu/g.

  6. Effect of solution pH value changes on fluorescence intensity of magnetic-luminescent Fe3O4@Gd2O3:Eu3+ nanoparticles

    Institute of Scientific and Technical Information of China (English)

    吴拓; 潘桦滟; 陈如标; 罗东; 张宏; 沈晔; 李旸晖; 王乐

    2016-01-01

    In this paper, bifunctional Fe3O4@Gd2O3:Eu3+ core-shell nanoparticles with both magnetic and fluorescent properties were synthesized through a urea homogeneous precipitation (UHP) method. Particular emphasis was placed on investigating the influence of the solution pH value on the photoluminescence of the core-shell nanocomposites. It showed that the samples treated at the solution of pH=3.0 had the highest luminescence due to the enhanced crystallinity and size uniformity of nanoparticles. The Fe3O4@Gd2O3:Eu3+ nanocomposites exhibited an almost spherical shape with a mean diameter of 60 nm, and had strong red emis-sions of Eu3+ at 612 nm as well as good magnetization with the saturation magnetization of 1.29 emu/g. It thus indicated that the core-shell nanocomposites investigated has great potential in biomedical applications.

  7. 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.

  8. Fast removal of malachite green dye using novel superparamagnetic sodium alginate-coated Fe3O4 nanoparticles.

    Science.gov (United States)

    Mohammadi, Abbas; Daemi, Hamed; Barikani, Mehdi

    2014-08-01

    In this study, superparamagnetic sodium alginate-coated Fe3O4 nanoparticles (Alg-Fe3O4) as a novel magnetic adsorbent were prepared by in situ coprecipitation method, in which Fe3O4 nanoparticles were precipitated from FeCl3 and FeCl2 under alkaline medium in the presence of sodium alginate. The Alg-Fe3O4 nanoparticles were used for removal of malachite green (MG) from aqueous solutions using batch adsorption technique. The characterization of synthesized nanoparticles was performed using XRD, FTIR, TEM, TGA and vibrating sample magnetometer (VSM) techniques. FTIR analysis of synthesized nanoparticles provided the evidence that sodium alginate was successfully coated on the surface of Fe3O4 nanoparticles. The FT-IR and TGA characterization showed that the Alg-Fe3O4 nanoparticles contained about 14% (w/w) of sodium alginate. Moreover, TEM analysis indicated that the average diameter of the Alg-Fe3O4 nanoparticles was about 12nm. The effects of adsorbent dosage, pH and temperature were investigated on the adsorption properties of MG onto Alg-Fe3O4 nanoparticles. The equilibrium adsorption data were modeled using the Langmuir and Freundlich isotherms. The maximum adsorption capacity obtained from Langmuir isotherm equation was 47.84mg/g. The kinetics of adsorption of MG onto Alg-Fe3O4 nanoparticles were investigated using the pseudo-first-order and pseudo-second-order kinetic models. The results showed that the adsorption of MG onto nanoparticles followed pseudo-second-order kinetic model. Copyright © 2014 Elsevier B.V. All rights reserved.

  9. Fast synthesis of dopamine-coated Fe3O4 nanoparticles through ligand-exchange method

    Institute of Scientific and Technical Information of China (English)

    Peng An; Fang Zuo; Yuan Peng Wu; Jun Hua Zhang; Zhao Hui Zheng; Xiao Bin Ding; Yu Xing Peng

    2012-01-01

    A fast approach was described for the synthesis of water-dispersible monodisperse dopamine-coated Fe3O4 nanoparticles (DA-Fe3O4) with uniform size and shape via ligand-exchange of oleic acid on Fe3O4 using only 2 min.The prepared DA-Fe3O4 nanoparticles were characterized by transmission electron microscopy,Fourier transform infrared spectrometry,and vibrating sample magnetometer.The results indicated that the resulting DA-Fe3O4 nanoparticles had an average diameter of about 19.2 nm.The magnetic saturation value of the prepared DA-Fe3O4 nanoparticles was determined to be 72.87 emu/g,which indicating a wellestablished superparamagnetic property.

  10. A moderate method for preparation DMSA coated Fe3O4 nanoparticles

    Science.gov (United States)

    Song, L. N.; Gu, N.; Zhang, Y.

    2017-01-01

    A moderate way to prepare water soluble magnetic Fe3O4 nanoparticles has been developed. Firstly, oleic acid coated Fe3O4 is prepared by coprecipitation. Second, oleic acid were replaced by 2,3-dimercaptosuccinnic acid (DMSA) to prepare DMSA/Fe3O4 in the mixed solution of n-hexane and acetone. After dialysis and filtration the DMSA/Fe3O4 can be transferred into distilled water to form stable Fe3O4 nanoparticle solutions. The TEM images indicated that the particles had spherical shape and the nanoparticles were found to be 12 nm with a relatively narrow size distribution with the hydrodynamic size of 30 nm. And the result of VSM shows that DMSA/Fe3O4 nanoparticles have a saturation magnetization of 31 emu/g. The IR spectra indicated that the iron oxide was located by carboxyl matrix.

  11. 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.

  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. Spectroscopic characterization of magnetic Fe3O4@Au core shell nanoparticles

    Science.gov (United States)

    Fouad, Dina M.; El-Said, Waleed A.; Mohamed, Mona B.

    2015-04-01

    The magnetic nanoparticles iron oxide (Fe3O4) nanoparticles and iron oxide/gold core-shell (Fe3O4/Au) nanoparticles were synthesized and their catalytic photo-degradation activity towards malathion as example of organophosphorus pesticides were reported. Iron oxide (Fe3O4) magnetic nanoparticle was successfully prepared through co-precipitation method by the reduction of ferric chloride (FeCl3) using ascorbic acid. The morphology of the prepared nanoparticles was characterized by the TEM and XRD (X-ray diffraction) techniques. Degradation of 10 ppm of malathion in the presence of these nanoparticles under UV radiation was monitored using (HPLC) and UV-visible spectra. Fe3O4/Au nanoparticles showed higher efficiency in photo-degradation of malathion than Fe3O4 ones.

  14. 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.

  15. Fe3O4 nanoparticles for magnetic hyperthermia and drug delivery; synthesis, characterization and cellular studies

    Science.gov (United States)

    Palihawadana Arachchige, Maheshika

    In recent years, magnetic nanoparticles (MNPs), especially superparamagnetic Fe3O4nanoparticles, have attracted a great deal of attention because of their potential applications in biomedicine. Among the other applications, Magnetic hyperthermia (MHT), where localized heating is generated by means of relaxation processes in MNPs when subjected to a radio frequency magnetic field, has a great potential as a non-invasive cancer therapy treatment. Specific absorption rate (SAR), which measures the efficiency of heat generation, depends on magnetic properties of the particles such as saturation magnetization (M s), magnetic anisotropy (K), particle size distribution, magnetic dipolar interactions, and the rheological properties of the target medium.We have investigated MHT in two Fe3O4 ferrofluids prepared by co-precipitation (CP) and hydrothermal (HT) synthesis methods showing similar physical particle size distribution and Ms, but very different SAR 110 W/g and 40 W/g at room temperature. This observed reduction in SAR has been explained by taking the dipolar interactions into account using the so called T* model. Our analysis reveals that HT ferrofluid shows an order of magnitude higher effective dipolar interaction and a wider distribution of magnetic core size of MNPs compared to that of CP ferrofluid. We have studied dextran coated Gd-doped Fe3O4 nanoparticles as a potential candidate in theronostics for multimodal contrast imaging and cancer treatment by hyperthermia. The effect of surfactant on the MHT efficiency and cytotoxicity on human pancreatic cancer cells was explored as well. Though further in vivo study is necessary in the future, these results imply that the dextran coated Fe3O4 dispersion could maintain their high heating capacity in physiological environments while citric acid coating require further surface modification to reduce the non-specific protein adsorption. We have also investigated the traffic, distribution, and cytotoxicity, associated

  16. Effective removal of toxic metal ions from aqueous solutions: 2-Bifunctional magnetic nanocomposite base on novel reactive PGMA-MAn copolymer@Fe3O4 nanoparticles.

    Science.gov (United States)

    Hasanzadeh, Reza; Moghadam, Peyman Najafi; Bahri-Laleh, Naeimeh; Sillanpää, Mika

    2017-03-15

    In this study, effective novel magnetic nanocomposite particles (MNCPs) were prepared based on iminodiacetic acid grafted poly (glycidylmethacrylate-maleicanhydride) (PGMA-MAn) copolymer. For this purpose, firstly Fe3O4 nanoparticles reacted with 3-aminopropyl triethoxysilane for the production of magnetite nanoparticles containing amine groups (MNPs-NH2). Then iminodiacetic acid reacted with PGMA-MAn copolymer to produce iminodiacetic acid grafted PGMA-MAn copolymer (ID-g-PGMA-MAn). Finally, the MNPs-NH2 reacted with the ID-g-PGMA-MAn and the reaction was completed by propylenediamine (PDA) to produce MNCPs. Structure, magnetic property, size, and porosity of the prepared magnetic nanocomposite were investigated by FT-IR, XRD, VSM, EDX, SEM and BET analyses. The ability of these MNCPs for removing Pb(II) and Cd(II) from water and wastewater was studied, and the effects of different parameters (pH, adsorbent dosage, metal ion concentration, contact time and agitation) on the adsorption process were investigated. The isotherm models were used to describe adsorption equilibrium. The results showed that the best fit was achieved with the Langmuir isotherm equation, yielding maximum adsorption capacities of 53.33 and 48.53mg/g for Pb(II) and Cd(II), respectively. The kinetics equations were used for modeling of adsorption data and it was shown that pseudo-second-order kinetic equation could best describe the adsorption kinetics. Furthermore, phenol pollutant can be removed effectively by metal ions of the nanocomposite-metal complex; therefore, the synthesized adsorbent was useful not only in recovering toxic metal ions but also in the treating phenol pollutants in wastewater.

  17. 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.

  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. 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

  1. 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.

  2. 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.

  3. Facile synthesis of size tunable Fe3O4 nanoparticles in bisolvent system

    Science.gov (United States)

    Huang, Zhuanzhuan; Wu, Kelu; Yu, Qiao-He; Wang, Yi-Yan; Xing, Jiayi; Xia, Tian-Long

    2016-11-01

    Magnetic nanoparticle clusters with magnetization of about 80 emu/g and tunable size between 55 and 500 nm were synthesized through a bisolvent solvothermal process in the presence of ethylene glycol (EG) and diethylene glycol (DEG), triethylene glycol (TEG) or 1,2-propanediol (PG) with polyethylene glycol (PEG) or hexadecyltrimethyl ammonium bromide (CTAB) as surfactant. It was found that the volume ratio of EG to the other polyol played an important role in controlling the size and morphology of Fe3O4. Effect of the concentration of Ferric chloride hexahydrate (FeCl3·6H2O) and original reactants on controlling the size of Fe3O4 particles was also discussed.

  4. [Adsorption of methylene blue from aqueous solution onto magnetic Fe3O4/ graphene oxide nanoparticles].

    Science.gov (United States)

    Chang, Qing; Jiang, Guo-Dong; Hu, Meng-Xuan; Huang, Jia; Tang, He-Qing

    2014-05-01

    A simple ultrasound-assisted co-precipitation method was developed to prepare magnetic Fe3O4/graphene oxide (Fe3O4/ GO) nanoparticles. The characterization with transmission electron microscope (TEM) indicated that the products possessed small particle size. The hysteresis loop of the dried Fe3O4/GO nanoparticles demonstrated that the sample had typical features of superparamagnetic material. Batch adsorption studies were carried out to investigate the effects of the initial pH of the solution, the dosage of adsorbent, the contact time and temperature on the adsorption of methylene blue. The results indicated that the composites prepared could be used over a broad pH range (pH 6-9). The adsorption process was very fast within the first 25 min and the equilibrium was reached at 180 min. The adsorption equilibrium and kinetics data fitted well with the Langmuir isotherm model and the pseudo-second-order kinetic model. The adsorption process was a spontaneous and endothermic process in nature. The composite exhibited fairly high adsorption capacity (196.5 mg.g-1) of methylene blue at 313 K. In addition, the magnetic composite could be effectively and simply separated by using an external magnetic field, and then regenerated by hydrogen peroxide and recycled for further use. The results indicated that the adsorbent had a potential in the application of the dye wastewater treatment.

  5. Preparation of CNC-dispersed Fe3O4 nanoparticles and their application in conductive paper.

    Science.gov (United States)

    Liu, Kai; Nasrallah, Joseph; Chen, Lihui; Huang, Liulian; Ni, Yonghao

    2015-08-01

    Well-dispersed Fe3O4 nanoparticles (NPs) were synthesized by a co-precipitation method in the presence of cellulose nano-crystals (CNC) as the template. The thus prepared Fe3O4 NPs were then used as a coating agent for the preparation of conductive paper. Fourier transform infrared spectroscopy (FTIR) results revealed that the Fe3O4 NPs were immobilized on the CNC through interactions between the hydroxyl groups of CNC and Fe3O4. Scanning transmission electron microscopy (STEM) images showed that the Fe3O4 NPs prepared in the presence of CNC can be dispersed in the CNC network, while the Fe3O4 NPs prepared in the absence of CNC tended to aggregate in aqueous solutions. The conductivity of the Fe3O4 NPs coated paper can reach to 0.0269 S/m at the coating amount of 14.75 g/m(2) Fe3O4/CNC nanocomposites. Therefore, the thus obtained coated paper can be potentially used as anti-static packaging material in the packaging field.

  6. 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.

  7. 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.

  8. Improving Pullulanase Catalysis via Reversible Immobilization on Modified Fe3O4@Polydopamine Nanoparticles.

    Science.gov (United States)

    Wang, Jianfeng; Liu, Zhongmei; Zhou, Zhemin

    2017-08-01

    To improve the catalysis of pullulanase from Anoxybacillus sp.WB42, Fe3O4@polydopamine nanoparticles (Fe3O4@PDA) were prepared and modified with functional groups for immobilization of pullulanases via covalent binding or ionic adsorption. Immobilized pullulanases had lower thermal stability than that of free pullulanase, whereas their catalysis depended on the surface characteristics of nanoparticles. As for covalent immobilization of pullulanases onto Fe3O4@PDA derivatives, the spacer grafted onto Fe3O4@PDA made the catalytic efficiency of pullulanase increase up to the equivalence of free enzyme but dramatically reduced the pullulanase thermostability. In contrast, pullulanases bounded ionically to Fe3O4@PDA derivatives had higher activity recovery and catalytic efficiency, and their catalytic behaviors varied with the modifier grafted onto Fe3O4@PDA. Among these immobilized pullulanases, ionic adsorption of pullulanase on Fe3O4@PDA-polyethyleneimine-glycidyltrimethylammonium gave a high-performance and durable catalyst, which displayed not only 1.5-fold increase in catalytic efficiency compared to free enzyme but also a significant improvement in operation stability with a half of initial activity after 27 consecutive cycles with a total reaction time of 13.5 h, and was reversible, making this nanoparticle reusable for immobilization.

  9. Synthesis of Fe3O4 nanoparticles and its antibacterial application

    Science.gov (United States)

    Prabhu, Y. T.; Rao, K. Venkateswara; Kumari, B. Siva; Kumar, Vemula Sesha Sai; Pavani, Tambur

    2015-02-01

    The Present work outlines the antibacterial activity of Fe3O4 nanoparticles synthesized through chemical combustion method where ferric nitrate is used as precursor material and urea as fuel with the assistant of Tween 80, a non-ionic surfactant. The obtained Fe3O4 nanoparticles were characterized by X-ray diffraction, differential thermal analysis/thermo gravimetric analysis (DTA/TGA), particle size analyzer, SEM with EDAX and TEM. Various parameters such as dislocation density, micro strain, analysis of weight loss and surface morphological studies were calculated. The particle size was calculated from XRD and it was found to be 33-40 nm. Using well diffusion method antibacterial activity of Fe3O4 nanoparticles was tested against gram-positive and gram-negative Staphylococus aureus, Xanthomonas, Escherichia coli and Proteus vulgaris. Fe3O4 nanoparticles exhibited strong antibacterial activity against bacterial species.

  10. 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+.

  11. 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.

  12. 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.

  13. 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.

  14. 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.

  15. 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. Copyright © 2015 Elsevier B.V. All rights reserved.

  16. Superparamagnetic Au-Fe3O4 nanoparticles: one-pot synthesis, biofunctionalization and toxicity evaluation

    Science.gov (United States)

    Pariti, A.; Desai, P.; Maddirala, S. K. Y.; Ercal, N.; Katti, K. V.; Liang, X.; Nath, M.

    2014-09-01

    Superparamagnetic Au-Fe3O4 bifunctional nanoparticles have been synthesized using a single step hot-injection precipitation method. The synthesis involved using Fe(CO)5 as iron precursor and HAuCl4 as gold precursor in the presence of oleylamine and oleic acid. Oleylamine helps in reducing Au3+ to Au0 seeds which simultaneously oxidizes Fe(0) to form Au-Fe3O4 bifunctional nanoparticles. Triton® X-100 was employed as a highly viscous solvent to prevent agglomeration of Fe3O4 nanoparticles. Detailed characterization of these nanoparticles was performed by using x-ray powder diffraction, transmission electron microscopy, scanning tunneling electron microscopy, UV-visible spectroscopy, Mössbauer and magnetometry studies. To evaluate these nanoparticles’ applicability in biomedical applications, L-cysteine was attached to the Au-Fe3O4 nanoparticles and cytotoxicity of Au-Fe3O4 nanoparticles was tested using CHO cells by employing MTS assay. L-cysteine modified Au-Fe3O4 nanoparticles were qualitatively characterized using Fourier transform infrared spectroscopy and Raman spectroscopy; and quantitatively using acid ninhydrin assay. Investigations reveal that that this approach yields Au-Fe3O4 bifunctional nanoparticles with an average particle size of 80 nm. Mössbauer studies indicated the presence of Fe in Fe3+ in A and B sites (tetrahedral and octahedral, respectively) and Fe2+ in B sites (octahedral). Magnetic measurements also indicated that these nanoparticles were superparamagnetic in nature due to Fe3O4 region. The saturation magnetization for the bifunctional nanoparticles was observed to be ˜74 emu g-1, which is significantly higher than the previously reported Fe3O4 nanoparticles. Mössbauer studies indicated that there was no significant Fe(0) impurity that could be responsible for the superparamagnetic nature of these nanoparticles. None of the investigations showed any presence of other impurities such as Fe2O3 and FeOOH. These Au-Fe3O4 bifunctional

  17. 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.

  18. Nanoparticle size matters in the formation of plasma protein coronas on Fe3O4 nanoparticles.

    Science.gov (United States)

    Hu, Zhengyan; Zhang, Hongyan; Zhang, Yi; Wu, Ren'an; Zou, Hanfa

    2014-09-01

    When nanoparticles (NPs) enter into biological systems, proteins would interact with NPs to form the protein corona that can critically impact the biological identity of the nanomaterial. Owing to their fundamental scientific interest and potential applications, Fe3O4 NPs of different sizes have been developed for applications in cell separation and protein separation and as contrast agents in magnetic resonance imaging (MRI), etc. Here, we investigated whether nanoparticle size affects the formation of protein coronas around Fe3O4 NPs. Both the identification and quantification results demonstrated that particle size does play an important role in the formation of plasma protein coronas on Fe3O4 NPs; it not only influenced the protein composition of the formed plasma protein corona but also affected the abundances of the plasma proteins within the coronas. Understanding the different binding profiles of human plasma proteins on Fe3O4 NPs of different sizes would facilitate the exploration of the bio-distributions and biological fates of Fe3O4 NPs in biological systems.

  19. Growth mechanism and magnetism in carbothermal synthesized Fe3O4 nanoparticles from solution combustion precursors

    Science.gov (United States)

    Wang, Xuanli; Qin, Mingli; Cao, Zhiqin; Jia, Baorui; Gu, Yueru; Qu, Xuanhui; Volinsky, Alex A.

    2016-12-01

    Magnetic Fe3O4 nanoparticles were prepared by carbothermal reduction using solution combustion synthesis precursors derived from ferric nitrate (oxidizer), glycine (fuel) and glucose (carbon source) mixed solution. In this paper, the growth mechanism and magnetism in Fe3O4 nanoparticles were investigated by adjusting the glucose content in precursor and the heat temperature in carbothermal process. The products were analyzed by X-ray diffraction, Field emission scanning electron microscopy, Infrared adsorption method and Vibrating sample magnetometry. The results revealed that the more amount of glucose, the earlier Fe3O4 phase generated as temperature increasing. Depending on glucose content and thermal temperature, the average grain size of Fe3O4 nanoparticles varied from 19.9 nm to 48 nm and saturation magnetization changed from 21.2 emu/g to 71.77 emu/g, which indicated that the saturation magnetization of Fe3O4 nanoparticles fell off as the average grain size decreasing. These results were crucial not only from the application stand-point, but more importantly leaded to a new platform for further studies of high quality magnetic Fe3O4 particles at nanoscale.

  20. Field-induced microwave absorption in Fe3O4 nanoparticles and Fe3O4/polyaniline composites synthesized by different methods

    Science.gov (United States)

    Kurlyandskaya, G. V.; Cunanan, Jessica; Bhagat, S. M.; Aphesteguy, J. C.; Jacobo, S. E.

    2007-08-01

    Three kinds of nanoscale powders containing Fe3O4 nanoparticles (NPs) have been studied by ferromagnetic resonance (FMR): (i) Fe3O4 NPs grown and then covered with polyaniline (PANI), (ii) unclad Fe3O4 NPs, and (iii) Fe3O4 NPs grown “in situ” with the PANI. In every case, there is no low field microwave absorption, rather a single FMR line is observed. However, the half-power widths are of order of 1 kOe presumably due to a distribution of internal fields. For type I particles with a low concentration (below 40%) of Fe3O4, the observed resonance fields (Hr) are close to those expected for spheres with negligible magnetocrystalline anisotropy. For all other cases, Hr values are significantly lower. Such shortfalls can be roughly understood by invoking dipolar interactions between the grains, stresses frozen in grains during manufacture (method III), as well as anisotropy fields when the specimens are prepared in an aligning field.

  1. 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.

  2. pH controlled release of chromone from chromone-Fe3O4 nanoparticles.

    Science.gov (United States)

    Wang, Baodui; Xu, Chenjie; Xie, Jin; Yang, Zhengyin; Sun, Shouheng

    2008-11-05

    We report a new strategy for coupling chromone to Fe3O4 nanoparticles. The chromone-Fe3O4 NP conjugate shows a dramatic increase in chromone solubility in cell culture medium from less than 2.5 to 633 microg/ml, leading to the enhanced chromone uptake by HeLa cells. Chromone can be released at low pH and as a result, the chromone-Fe3O4 conjugate is much more efficient in inhibiting the HeLa cell proliferation. Such chromone-Fe3O4 NPs are promising as a powerful multifunctional delivery system for both chromone-based diagnostic and therapeutic applications.

  3. Tailoring the nickel nanoparticles anchored on the surface of Fe3O4@SiO2 spheres for nanocatalysis

    Science.gov (United States)

    Ding, Lei; Zhang, Min; Zhang, Yanwei; Yang, Jinbo; Zheng, Jing; Hayat, Tasawar; Alharbi, Njud S.; Xu, Jingli

    2017-08-01

    Herein, we report an efficient and universal strategy for synthesizing a unique triple-shell structured Fe3O4@SiO2@C-Ni hybrid composite. Firstly, the Fe3O4 cores were synthesized by hydrothermal reaction, and sequentially coated with SiO2 and a thin layer of nickel-ion-doped resin-formaldehyde (RF-Ni2+) using an extended Stöber method. This was followed by carbonization to produce the Fe3O4@SiO2@C-Ni nanocomposites with metallic nickel nanoparticles embedded in an RF-derived thin graphic carbon layer. Interestingly, the thin SiO2 spacer layer between RF-Ni2+ and Fe3O4 plays a critical role on adjusting the size and density of the nickel nanoparticles on the surface of Fe3O4@SiO2 nanospheres. The detailed tailoring mechanism is explicitly discussed, and it is shown that the iron oxide core can react with the nickel nanoparticles without the SiO2 spacer layer, and the size and density of the nickel nanoparticles can be effectively controlled when the SiO2 layer exits. The multifunctional composites exhibit a significantly enhanced catalytic performance in the reduction of 4-nitrophenol (4-NP).

  4. Synthesis and characterization of surface-modified Fe3O4 super-paramagnetic nanoparticles.

    Science.gov (United States)

    Zhang, Zhan-jie; Ma, Jia; Xu, Shuang-bing; Ren, Jing-hua; Qin, You; Huang, Jing; Yang, Kun-yu; Zhang, Zhi-ping; Wu, Gang

    2014-04-01

    Aqueous dispersion and stability of Fe3O4 nanoparticles remain an issue unresolved since aggregation of naked iron nanoparticles in water. In this study, we successfully synthesized different Fe3O4 super-paramagnetic nanoparticles which were modified by three kinds of materials [DSPE-MPEG2000, TiO2 and poly acrylic acid (PAA)] and further detected their characteristics. Transmission electron microscopy (TEM) clearly showed sizes and morphology of the four kinds of nanoparticles. X-ray diffraction (XRD) proved successfully coating of the three kinds of nanoparticles and their structures were maintained. Vibrating sample magnetometer (VSM) verified that their magnetic properties fitted for the super-paramagnetic function. More importantly, the particle size analysis indicated that Fe3O4@PAA had a better size distribution, biocompatibility, stability and dispersion than the other two kinds of nanoparticles. In addition, using CNE2 cells as a model, we found that all nanoparticles were nontoxic. Taken together, our data suggest that Fe3O4@PAA nanoaparticles are superior in the application of biomedical field among the four kinds of Fe3O4 nanoparticles in the future.

  5. 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.

  6. Sulfonated Magnetic Nanocomposite Based on Reactive PGMA-MAn Copolymer@Fe3O4 Nanoparticles: Effective Removal of Cu(II Ions from Aqueous Solutions

    Directory of Open Access Journals (Sweden)

    Reza Hasanzadeh

    2016-01-01

    Full Text Available Chelating magnetic nanocomposites have been considered as suitable materials for removal of heavy metal ions for water treatment. In this work poly(glycidyl methacrylate-maleic anhydride copolymer (PGMA-MAn is modified with 4-aminobenzenesulfonic acid (ABSAc and subsequently the product reacted with modified Fe3O4 nanoparticles and 1,2-ethanedithiol (EDT in the presence of ultrasonic irradiation for preparation of tridimensional chelating magnetic nanocomposite. Synthesized magnetic nanocomposite was characterized by Fourier transform infrared spectroscopy (FT-IR, scanning electron microscopy (SEM, X-ray diffraction analysis (XRD, vibrating sample magnetometer (VSM, energy dispersive X-ray analysis (EDX, elemental mapping analysis (EMA, Brunauer-Emmett-Teller (BET, and thermal gravimetric analysis (TGA. The adsorption behavior of Cu(II ions was investigated by synthesized nanocomposite in various parameters such as pH, contact time, metal ion concentration, and adsorbent dosage. The equilibrium distribution coefficient (kd was determined and the findings prove that the kd value is approximately high in the case of all selected metal ions. The synthesized nanocomposite exhibited good tendency for removing Cu(II ions from aqueous solutions even at an acidic pH.

  7. 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。

  8. Dose-dependent Cytotoxicity and Oxidative Stress Induced by "Naked" Fe3O4 Nanoparticles in Human Hepatocyte

    Institute of Scientific and Technical Information of China (English)

    LIN Xin-li; ZHAO Shu-hua; ZHANG Long; HU Gui-qin; SUN Zhi-wei; YANG Wen-sheng

    2012-01-01

    The dose-dependent cytotoxicity effect on human hepatocyte(HL-7702 cells) induced by "naked" Fe3O4 nanoparticles was assessed through cell viabilities and lactate dehydrogenase(LDH) activities.Three important oxidative indexes of the cells by glutathione peroxidase(GSH-Px),superoxide dismutase(SOD) and malondialdehyde(MDA) were determined.The good correlation of the cell viabilities with their GSH-Px,SOD and MDA levels indicated that the cytotoxicity is related to activation of oxidative stress induced by Fe3O4 nanoparticles.The oxidative stress also leads to corresponding DNA damage in a similar dose-dependent manner,followed by the changes of cell cycle and cell apoptosis.Such work provides important experimental data for the safety evaluation of superparamagnetic Fe3O4 nanoparticles.

  9. Synthesis and characterization of Fe3O4@ZnS and Fe3O4@Au@ZnS core-shell nanoparticles

    Science.gov (United States)

    Stefan, M.; Leostean, C.; Pana, O.; Soran, M.-L.; Suciu, R. C.; Gautron, E.; Chauvet, O.

    2014-01-01

    In the present work we report new assets on the synthesis and characterization of magnetite based core-shell nanoparticles such as Fe3O4@ZnS and Fe3O4@Au@ZnS. The composites were prepared by seed mediated growth which consist in a sequential growth of a second or third component on a preformed magnetite seeds in the presence of sodium laurylsulphate additives with essential role in growth and aggregation of nanoparticles. Evolved gas analysis (EGA) coupled with FT-IR was used in order to evidence the stages of ZnS shell formation. XRD studies were used for the structural characterization while high resolution transmission electron microscopy gave information concerning morphology and size distributions of nanoparticles. Qualitative and quantitative compositional analysis of samples was made by X-ray photoelectron spectroscopy (XPS). All the samples showed magnetic response due to the superparamagnetic behavior of magnetite cores. Increased saturation magnetization was determined for Fe3O4@ZnS samples. A significant photoluminescence (PL) enhancement was also observed as a result of Fe3O4:Zn2+ molar ratio decrease. Additional PL increased response was realized by inserting a gold shell between the magnetite core and ZnS outer shell. Considerations regarding both PL and magnetization enhancements are also presented.

  10. Comparison of schemes for preparing magnetic Fe3O4 nanoparticles

    Institute of Scientific and Technical Information of China (English)

    Ruoyu Hong; Jianhua Li; Jian Wang; Hongzhong Li

    2007-01-01

    Magnetic Fe3O4 nanoparticles were prepared by means of coprecipitation using NH3·H2O in water and in alcohol, and using NaOH in water. A series of instruments such as SEM, TEM, HRTEM, FT-IR, XRD and VSM were used to characterize the properties of the magnetic nanoparticles.was the longest. The process using NaOH in water was the simplest and the reaction time was the shortest, but the particle characteristics were inferior to those of the other two methods. The mean size of magnetic Fe3O4 nanoparticles prepared by coprecipitation in alcohol was the smallest among the three, but the nanoparticles aggregated severely. The magnetic Fe3O4 nanoparticles were coated with oleic acid using saturated sodium coated successfully and thoroughly.

  11. Conjugating folate on superparamagnetic Fe3O4@Au nanoparticles using click chemistry

    Science.gov (United States)

    Shen, Xiaofang; Ge, Zhaoqiang; Pang, Yuehong

    2015-02-01

    Gold-coated magnetic core@shell nanoparticles, which exhibit magneto-optical properties, not only enhance the chemical stability of core and biocompatibility of surface, but also provide a combination of multimodal imaging and therapeutics. The conjugation of these tiny nanoparticles with specific biomolecules allows researchers to target the desired location. In this paper, superparamagnetic Fe3O4@Au nanoparticles were synthesized and functionalized with the azide group on the surface by formation of self-assembled monolayers. Folate (FA) molecules, non-immunogenic target ligands for cancer cells, are conjugated with alkyne and then immobilized on the azide-terminated Fe3O4@Au nanoparticles through copper(I)-catalyzed azide-alkyne cycloaddition (click reaction). Myelogenous leukemia K562 cells were used as a folate receptor (FR) model, which can be targeted and extracted by magnetic field after interaction with the Fe3O4@Au-FA nanoparticles.

  12. Catalytic wet air oxidation of phenol over Co-doped Fe3O4 nanoparticles

    Science.gov (United States)

    Song, Xu Chun; Zheng, Yi Fan; Yin, Hao Yong

    2013-08-01

    The Fe3O4 nanoparticles doped with cobalt ions have been successfully synthesized by the co-precipitation process. The X-ray diffraction, inductively coupled plasma, scanning electron microscopy, and transmission electron microscopy were used to characterize the as-prepared nanoparticles. The results show that the phase structure of the nanoparticles is spinel structure of pure Fe3O4 with the particle size ranging from 40 to 50 nm. The Co-doping concentration can be controlled by changing the atomic ratio of the stock materials. The catalytic activity of the Co-doped Fe3O4 was further investigated by decomposing the phenol in liquid phase. The results show that cobalt ions doping can improve the catalytic efficiency of Fe3O4 nanoparticles in phenol degradation with catalytic reaction fitting the first-order kinetics. According to the estimated reaction rate of Co-doped Fe3O4 nanoparticles at different temperatures, the activation energy was calculated to be 45.63 kJ/mol.

  13. Efficient removal of arsenite through photocatalytic oxidation and adsorption by ZrO2-Fe3O4 magnetic nanoparticles

    Science.gov (United States)

    Sun, Tianyi; Zhao, Zhiwei; Liang, Zhijie; Liu, Jie; Shi, Wenxin; Cui, Fuyi

    2017-09-01

    Bifunctional ZrO2-Fe3O4 magnetic nanoparticles were synthesized and characterized, to remove As(III) through photocatalyic oxidation and adsorption. With a saturation magnetization of 27.39 emu/g, ZrO2-Fe3O4 nanoparticles with size of 10-30 nm could be easily separated from solutions with a simple magnetic process. Under UV light, As(III) could be completely oxidized to less toxic As(V) by ZrO2-Fe3O4 nanoparticles within 40 min in the photocatalytic reaction. Simultaneously, As(V) could be adsorbed onto the surface of nanoparticles with high efficiency. The adsorption of As(V) was well fitted by the pseudo-second-order model and the Freundlich isotherm model, respectively, and the maximum adsorption capacities of the nanoparticles was 133.48 mg/g at pH 7.0. As(III) could be effectively removed by ZrO2-Fe3O4 nanoparticles at initial pH range from 4 to 8. Among all the common coexisting ions investigated, except for chloride and sulfate, carbonate, silicate and phosphate decreased the As(III) removal by competing with arsenic species for adsorption sites. The synthesized magnetic ZrO2-Fe3O4 combined the photocatalytic oxidation property of ZrO2 and the high adsorption capacity of both ZrO2 and Fe3O4, which make it have significant potential applications in the As(III)-contaminated water treatment.

  14. Size-Controlled Synthesis of Fe3O4 Magnetic Nanoparticles in the Layers of Montmorillonite

    Directory of Open Access Journals (Sweden)

    Katayoon Kalantari

    2014-01-01

    Full Text Available Iron oxide nanoparticles (Fe3O4-NPs were synthesized using chemical coprecipitation method. Fe3O4-NPs are located in interlamellar space and external surfaces of montmorillonite (MMT as a solid supported at room temperature. The size of magnetite nanoparticles could be controlled by varying the amount of NaOH as reducing agent in the medium. The interlamellar space changed from 1.24 nm to 2.85 nm and average diameter of Fe3O4 nanoparticles was from 12.88 nm to 8.24 nm. The synthesized nanoparticles were characterized using some instruments such as transmission electron microscopy, powder X-ray diffraction, energy dispersive X-ray spectroscopy, field emission scanning electron microscopy, vibrating sample magnetometer, and Fourier transform infrared spectroscopy.

  15. Functionalized magnetic core-shell Fe3O4@SiO2 nanoparticles for sensitive detection and removal of Hg2+

    Science.gov (United States)

    Xu, Yaohui; Zhou, Yang; Ma, Wenhui; Wang, Shixing; Li, Shaoyuan

    2013-06-01

    The Fe3O4 nanoparticles [NPs] coated with silica nanoparticles were designed and prepared, the obtained Fe3O4@SiO2 NPs have uniform spherical morphology with a mean diameter of about 22 nm. The inert silica coating on the surface of Fe3O4 NPs not only significantly prevented their aggregation in solution but also improved their chemical stability and provided wider sites for surface modification with organic chemosensors. Subsequently an attempt had been made that the as-synthesized Fe3O4@SiO2 NPs were modified by N-(rhodamine-6G) lactam-ethylenediamine, the functionalized magnetic Fe3O4@SiO2 NPs (Fe3O4@SiO2-Rho) served as a "naked eye" fluorescent sensor to detect Hg2+. The Fe3O4@SiO2-Rho NPs exhibited selective "turn-on" type fluorescent change from colorless to orange when adding to Hg2+. In addition, the adsorption experiments revealed that the Fe3O4@SiO2-Rho NPs had effective removal toward Hg2+. Moreover, the functionalized Fe3O4@SiO2 microspheres displayed superparamagnetic properties, which made it easier to separate the nanocomposites from the liquid phase by adding an external magnetic field. Our efforts provided a potential magnetic nanomaterial for sensitive detection and removal toward Hg2+ simultaneously.

  16. 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.

  17. 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.

  18. Functionalized Magnetic Fe3O4-β-Cyclodextran Nanoparticles for Efficient Removal of Bilirubin.

    Science.gov (United States)

    Han, Lulu; Chu, Simin; Wei, Houliang; Ren, Jun; Xu, Li; Jia, Lingyun

    2016-06-01

    Bilirubin (BR), as a lipophilic toxin, can binds and deposits in various tissues, especially the brain tissue, leading to hepatic coma and even death. Magnetic nanoparticles adsorbent modified by β-cyclodextran (Fe3O4-β-CD) was developed to remove the BR from the plasma. Fe3O4-β-CD nanoparticles was prepared through Schiff base reaction between the polyethylenimine (PEI)-modified Fe3O4 and aldehyde-functionalized β-CD, and characterized by Fourier transform infrared (FTIR) spectra, X-ray diffraction (XRD), transmission electron microscopy (TEM), vibrating sample magnetometer (VSM) and dynamic light scattering (DLS). Under optimized conditions, the Fe3O4-β-CD adsorbent could adsorb 225.6 mg/g free BR in PBS and reach the adsorption equilibrium within 90 min mainly through hydrophobic interaction; Moreover, the adsorbent displayed better adsorption capability in a dialysis system for BSA-bound bilirubin, plasma bilirubin and total bile acid, and the removal rates of those were 66%, 31% and 41% respectively. Because of the advantages of fast separation and purification process, low preparation cost, good adsorption capability for plasma bilirubin, Fe3O4-β-CD may become an economical and promising absorbent of BR for clinical applications.

  19. Pickering-type ASA emulsions stabilized by Fe3O4 nanoparticles%纳米Fe3O4稳定的Pickering型ASA乳液

    Institute of Scientific and Technical Information of China (English)

    林兆云; 于得海; 李友明

    2014-01-01

    利用纳米Fe3O4作为稳定剂和乳化剂来制备Pickering型ASA(alkenyl succinic anhydride)施胶乳液,并研究了固体颗粒浓度、油水比、水分散相pH对乳液类型、稳定性、形态及施胶性能的影响。结果表明,纳米Fe3O4能够乳化制备均一稳定的Pickering型ASA乳液。乳液在室温下静置稳定,析出油相体积分数随固体颗粒用量的增加而增大,随油水比的增大而减小。油水比为2:1,水分散相浓度为0.1%(质量分数)时制备的ASA乳液稳定性最佳。固体颗粒部分吸附在油/水界面处,部分分散在分散相中,随分散相中固体颗粒浓度的增加,乳液稳定性变差。乳液静置分层之前,ASA发生部分水解。在放置1 h后用于纸页浆内施胶,随ASA乳液用量的增加,纸页表面接触角逐渐增大,且纸页表面粗糙度下降。在ASA的添加量为1.0%(质量分数)时,纸页表面接触角达到93.5°,纸页表面粗糙度为15.924μm。%Fe3O4 nanoparticles were used as stabilizer and emulsifier to prepare Pickering-type ASA (alkenyl succinic anhydride) emulsions, and the effects of particles concentration, volume ratio of oil/water and pH value on the type, stability, morphology and sizing performance of the emulsions were investigated. Fe3O4 nanoparticles were able to emulsify ASA to prepare homogeneous emulsions. When emulsions were placed without stirring at room temperature, the separated oil phase fraction increased with increasing particles concentration and decreased with increasing volume ratio of oil/water. Emulsions could keep homogeneous phase for 6 h as volume ratio of oil/water was 2 and particles concentration was 0.1%(mass). For stable emulsions, part of particles was absorbed at liquid-liquid interface and part of particles entered the dispersed phase, the stability of emulsions reduced with increasing particles concentration. Before the emulsions creamed, hydrolysis resistance was investigated

  20. Removal of Organophosphorus Pesticides from Aqueous Solution by Magnetic Fe3O4/Red Mud-Nanoparticles.

    Science.gov (United States)

    Aydin, Senar

    2016-12-01

      The aim of this study was to investigate the usability of magnetic Fe3O4/red mud nanoparticles (NPs) for the removal of organophosphorus pesticides from water samples. The effect of various experimental parameters such as red mud amount in Fe3O4/red mud-NPs, pH, contact time, initial pesticide concentrations and adsorbent dose was studied in order to find the optimum conditions for their removal in a batch process. The Fe3O4/red mud-NPs were characterized by using TGA, SEM, XRD, VSM, and determination of the BET surface area. After the regenerated Fe3O4/red mud-NPs were used three times, the sorption capacity and the magnetic separability were observed to be unaffected. Freundlich model described the sorption process better than Langmuir isotherm and the pseudo second-order kinetic model was determined as the best-fit model. The film diffusion mechanism was found to be a main rate control mechanism. The Fe3O4/red mud-NPs satisfactorily removed the OPPS from real water samples.

  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. Effect of MgO on Oxidation Process of Fe3 O4 in Pellets

    Institute of Scientific and Technical Information of China (English)

    Qiang-jian GAO; Yan-song SHEN; Xin JIANG; Hai-yan ZHENG; Feng-man SHEN; Chang-sheng LIU

    2016-01-01

    Induration process of oxidized pellets involves the oxidation of Fe3 O4 and re-crystallization of Fe2 O3 .The oxidation process of Fe3 O4 is significant for pellets to obtain better ambient strength.Thus,the effect of MgO on oxidation process of Fe3 O4 was investigated.The unreacted core model was applied to analyze the oxidizing indura-tion process of pellets.The experimental results show that MgO plays a negative role in the oxidation process of Fe3 O4 .The oxidation rate of Fe3 O4 in MgO-fluxed pellets (95.0% Fe3 O4+5.0% MgO)is slower than that in standard acid pellets (100% Fe3 O4 ).The relation between oxidation ratio of Fe3 O4 and time was calculated based on the unreacted core model for both MgO-fluxed pellets and standard acid pellets.According to verification experi-ments,the values calculated by model coincide well with the experimental values.Therefore,the unreacted core model could be applied to describe the oxidizing induration process of pellets.

  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. Lipase NS81006 immobilized on Fe3O4 magnetic nanoparticles for biodiesel production

    Directory of Open Access Journals (Sweden)

    Thangaraj Baskar

    2016-06-01

    Full Text Available Lipase-catalyzed biodiesel production is being the object of extensive research due to the demerits of chemical based catalytic system. Lipase immobilized on Fe3O4 magnetic nanoparticles has the integrated advantages of traditional immobilized lipase and free lipase for its rather fast reaction rate and easy separation. It has been demonstrated that free lipase NS81006 has potential in catalyzing the alcoholysis of renewable oils for biodiesel preparation. In this study, Fe3O4 magnetic nanoparticles functionalized with organosilane compounds like (3-aminopropyltriethyloxysilane (APTES and (3-mercaptopropyltrimethoxysilane MPTMS were used as carriers for lipase immobilization. Lipase NS81006 was covalently bound to the organosilane-functionalized magnetic nanoparticles by using glutaraldehyde cross-linking reagent. A biodiesel yield of 89% and 81% could be achieved by lipase immobilized on APTES-Fe3O4 and MPTMS-Fe3O4 magnetic nanoparticles respectively under optimized conditions of oil to methanol molar ratio 1:3 with three step addition of methanol, reaction temperature 45°C and reaction time duration 12 h. The lipases immobilized on magnetic nanoparticles could be recovered easily by external magnetic field for further use.

  5. 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

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

    Directory of Open Access Journals (Sweden)

    Gang Yuan

    2014-10-01

    Full Text Available 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 as a first step. Due to the successful coating of PEG molecules on the surface of PEG–Fe3O4, these nanoparticles exhibited excellent dispersibility and dissolvability in physiological condition. Cytotoxicity based on MTT assays indicated these nanoparticles revealed high biocompatibility and low toxicity towards both Hela cells and C6 cells. After near-infrared (NIR laser irradiation, the viabilities of C6 cells were effectively suppressed when incubated with the NIR laser activated PEG–Fe3O4. In addition, detailed photothermal anti-cancer efficacy was evaluated via visual microscope images, demonstrating that our PEG–Fe3O4 were promising for photothermal therapy of cancer cells.

  7. SYNTHESIS OF M–Nd DOPED Fe3O4 NANOPARTICLES (M = Co ...

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    series of Nd, Nd-Co, Nd-Ce, Nd-Cr, Nd-Ni doped Fe3O4 nanoparticles were ... good crystal structure, small particle size and high magnetic saturation. ... mmol) and salt of M (3.6×10-3 mmol) (salt of M: cobalt nitrate or chromium(III) nitrate or.

  8. Differential response of macrophages to core-shell Fe3O4@Au nanoparticles and nanostars

    Science.gov (United States)

    Xia, Wei; Song, Hyon-Min; Wei, Qingshan; Wei, Alexander

    2012-10-01

    Murine RAW 264.7 cells were exposed to spheroidal core-shell Fe3O4@Au nanoparticles (SCS-NPs, ca. 34 nm) or nanostars (NSTs, ca. 100 nm) in the presence of bovine serum albumin, with variable effects observed after macrophagocytosis. Uptake of SCS-NPs caused macrophages to adopt a rounded, amoeboid form, accompanied by an increase in surface detachment. In contrast, the uptake of multibranched NSTs did not induce gross changes in macrophage shape or adhesion, but correlated instead with cell enlargement and signatures of macrophage activation such as TNF-α and ROS. MTT assays indicate a low cytotoxic response to either SCS-NPs or NSTs despite differences in macrophage behavior. These observations show that differences in NP size and shape are sufficient to produce diverse responses in macrophages following uptake.Murine RAW 264.7 cells were exposed to spheroidal core-shell Fe3O4@Au nanoparticles (SCS-NPs, ca. 34 nm) or nanostars (NSTs, ca. 100 nm) in the presence of bovine serum albumin, with variable effects observed after macrophagocytosis. Uptake of SCS-NPs caused macrophages to adopt a rounded, amoeboid form, accompanied by an increase in surface detachment. In contrast, the uptake of multibranched NSTs did not induce gross changes in macrophage shape or adhesion, but correlated instead with cell enlargement and signatures of macrophage activation such as TNF-α and ROS. MTT assays indicate a low cytotoxic response to either SCS-NPs or NSTs despite differences in macrophage behavior. These observations show that differences in NP size and shape are sufficient to produce diverse responses in macrophages following uptake. Electronic supplementary information (ESI) available: Synthetic details, additional TEM images, absorbance spectra, and DLS analysis of SCS-NPs and NSTs, negative and positive control images of ROS imaging, and the effect of magnetic field gradient on ROS production. See DOI: 10.1039/c2nr32070c

  9. 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.

  10. 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.

  11. Preparation and characterization of spindle-like Fe3O4 mesoporous nanoparticles

    Directory of Open Access Journals (Sweden)

    Zhang Shaofeng

    2011-01-01

    Full Text Available Abstract Magnetic spindle-like Fe3O4 mesoporous nanoparticles with a length of 200 nm and diameter of 60 nm were successfully synthesized by reducing the spindle-like α-Fe2O3 NPs which were prepared by forced hydrolysis method. The obtained samples were characterized by transmission electron microscopy, powder X-ray diffraction, attenuated total reflection fourier transform infrared spectroscopy, field emission scanning electron microscopy, vibrating sample magnetometer, and nitrogen adsorption-desorption analysis techniques. The results show that α-Fe2O3 phase transformed into Fe3O4 phase after annealing in hydrogen atmosphere at 350°C. The as-prepared spindle-like Fe3O4 mesoporous NPs possess high Brunauer-Emmett-Teller (BET surface area up to ca. 7.9 m2 g-1. In addition, the Fe3O4 NPs present higher saturation magnetization (85.2 emu g-1 and excellent magnetic response behaviors, which have great potential applications in magnetic separation technology.

  12. One-step hydrothermal synthesis of magnetic Fe3O4 nanoparticles immobilized on polyamide fabric

    Science.gov (United States)

    Zhang, Hui; Zhu, Guoqing

    2012-03-01

    A thin film of nanosized Fe3O4 particles prepared by hydrothermal method was immobilized on the surface of polyamide 6 fiber using ferric trichloride and ferrous chloride as the precursor, N,N-dimethyl formamide as the swelling agent and sodium dodecyl sulfate as the dispersant agent. The morphology, crystalline phase, thermal stability, magnetization properties and chemical structure of polyamide 6 fabric before and after treatments were characterized by means of scanning electron microscope (SEM), transmission electron microscope (TEM), X-ray diffraction (XRD), thermal gravimetric analysis (TGA), differential scanning calorimetry (DSC), vibrating sample magnetometer (VSM) and X-ray photoelectron spectroscopy (XPS) techniques. The tensile properties and abrasion resistance were also measured. It was found that the inverse cubic spinel phase of Fe3O4 nanoparticles with an average size 50 nm were synthesized, and synchronously grafted onto polyamide fiber surface. As compared with the original fabric, the onset decomposition temperature of the Fe3O4-coated fabric decreased slightly. The saturation magnetization was measured to be 3.8 emu/g at temperature of 300 K. The tensile properties were enhanced to some extent mainly due to the fabric shrinkage. The abrasion resistance of the Fe3O4-coated fabric behaved well.

  13. Copper Ferrocyanide-Functionalized Magnetic Adsorbents Using Polyethyleneimine Coated Fe3O4 Nanoparticles for the Removal of Radioactive Cesium.

    Science.gov (United States)

    Yang, Hee-Man; Hong, Sang Bum; Cho, Yong Suk; Lee, Kune-Woo; Seo, Bum-Kyoung; Moon, Jei-Kwon

    2016-03-01

    Copper ferrocyanide-functionalized magnetic nano-adsorbents were successfully synthesized by electrostatic coating of citric acid coated Fe3O4 nanoparticles with polyethyleneimine, and immobilizing copper and ferrocyanide on the surfaces of polyethyleneimine-coated nanoparticles. Radioactive cesium (Cs) adsorption tests were conducted to investigate the effectiveness of the copper ferrocyanide-functionalized magnetic nano-adsorbents toward the removal of radioactive Cs.

  14. 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.

  15. 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.

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

    Science.gov (United States)

    Li, Ke; Chen, Baoan; Xu, Lin; Feng, Jifeng; Xia, Guohua; Cheng, Jian; Wang, Jun; Gao, Feng; Wang, Xuemei

    2013-01-01

    The purpose of this study was to explore whether magnetic Fe(3)O(4) nanoparticles (Fe(3)O(4)-MNP) loaded with cisplatin (Fe(3)O(4)-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 Fe(3)O(4)-MNP. An increased rate of apoptosis was detected in the Fe(3)O(4)-MNP-DDP group compared with a control group and the Fe(3)O(4)-MNP group by flow cytometry, and typical morphologic features of apoptosis were confirmed by confocal microscopy. Accumulation of intracellular DDP in the Fe(3)O(4)-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 Fe(3)O(4)-MNP-DDP. We also demonstrated that Fe(3)O(4)-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 Fe(3)O(4)-MNP-DDP to increase cytotoxicity in lung tumor xenografts.

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

    Science.gov (United States)

    Mihaiescu, Dan Eduard; Buteică, Alice Sandra; Neamţu, Johny; Istrati, Daniela; Mîndrilă, Ion

    2013-08-01

    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.

  18. 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

  19. 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.

  20. Synthesis and characterization of graphene patterned with Fe3 O 4 nanoparticles

    Science.gov (United States)

    Chandra, Sayan; Stojak, K.; Ferizovic, D.; Munoz, M.; Phan, M. H.; Srikanth, H.

    2011-03-01

    Graphene has emerged as a very exciting material with its outstanding physical, chemical, and mechanical properties. Due to the presence of excess free electrons on a graphene surface, the possibility of graphene-mediated long-range interactions between magnetic nanoparticles would open up new avenues of research and device development. Our studies aimed to deposit ~ 9 nm Fe 3 O4 NPs on graphene layers to understand the role of the metallic interface in mediating the magnetic interactions between the particles. We successfully grew the high-quality graphene on Ni films using CVD and used the Langmuir-Blodgett technique to pattern different layers of the Fe 3 O4 nanoparticles on the graphene sheets. The samples were well structurally characterized by XRD, TEM, AFM, and Raman spectroscopy. Interestingly we have observed strong variation in the magnetic properties such as magnetic anisotropy of the NPs pattered graphene samples when compared to just the NPs. These results point to the important role of the metallic interface in mediating the magnetic interactions between the Fe 3 O4 nanoparticles.

  1. 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.

  2. 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

  3. Fabrication of docetaxel surfaced Fe3O4 magnetite nanoparticles and their cytotoxicity on 4 T1 breast cancer cells

    Directory of Open Access Journals (Sweden)

    Yazdi MH

    2012-08-01

    Full Text Available Abstract 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 μg pure docetaxel compound. Docetaxel showed aniproliferative effects against mentioned cell line. The higestest concentartion of docetaxel (80 μg/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 μg/ml can exhibit higher cytotoxic effect against this cancer cell line (90% cell death.

  4. Development of poly(vinyl acetate-methylacrylic acid)/chitosan/Fe3O4 nanoparticles for the diagnosis of non-alcoholic steatohepatitis with magnetic resonance imaging.

    Science.gov (United States)

    Luo, Xiadan; Song, Xiaoli; Zhu, Aiping; Si, Yunfeng; Ji, Lijun; Ma, Zhanrong; Jiao, Zhiyun; Wu, Jingtao

    2012-12-01

    Non-alcoholic steatohepatitis is a burgeoning health problem. To diagnose NASH with magnetic resonance imaging (MRI), an effective contrast agent, a stable suspension of superparamagnetic Fe(3)O(4) nanoparticles, were newly developed. The negatively charged Fe(3)O(4) nanoparticles were coated with positive chitosan (CS) firstly, and then assembled with poly(vinyl acetate-methylacrylic acid) (P(VAc-MAA)). Transmission electron microscope and dynamic light scattering confirmed that the obtained P(VAc-MAA)/CS/Fe(3)O(4) nanoparticles had a spherical or ellipsoidal morphology with an average diameter in the range of 14-20 nm. The superparamagnetic property and spinel structure of the Fe(3)O(4) nanoparticles were well preserved due to the protection of the P(VAc-MAA)/CS layers on the surface of the Fe(3)O(4) nanoparticles. The in vivo rat experiments confirmed that the P(VAc-MAA)/CS/Fe(3)O(4) nanoparticles were an effective contrast agent for MRI to diagnose NASH.

  5. Functional Fe3O4/TiO2 core/shell magnetic nanoparticles as photokilling agents for pathogenic bacteria.

    Science.gov (United States)

    Chen, Wei-Jen; Tsai, Pei-Jane; Chen, Yu-Chie

    2008-04-01

    A photokilling approach for pathogenic bacteria is demonstrated using a new type of magnetic nanoprobe as the photokilling agent. In addition to their magnetic property, the nanoprobes have other features including a photocatalytic property and the capacity to target bacteria. The nanoprobes comprise iron oxide/titania (Fe(3)O(4)@TiO(2)) core/shell magnetic nanoparticles. As dopamine molecules can self-assemble onto the surface of the titania substrate, dopamine is used as the linker to immobilize succinic anhydride onto the surfaces of the Fe(3)O(4)@TiO(2) nanoparticles. This is followed by the immobilization of IgG via amide bonding. We demonstrate that the IgG-Fe(3)O(4)@TiO(2) magnetic nanoparticles not only have the capacity to target several pathogenic bacteria, but they also can effectively inhibit the cell growth of the bacteria targeted by the nanoparticles under irradiation of a low-power UV lamp within a short period. Staphylococcus saprophyticus, Streptococcus pyogenes, and antibiotic-resistant bacterial strains, such as multiantibiotic-resistant S. pyogenes and methicillin-resistant Staphylococcus aureus (MRSA), are used to demonstrate the feasibility of this approach.

  6. 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.

  7. Shape Memory Polymer Composites of Poly(styrene-b-butadiene-b-styrene Copolymer/Liner Low Density Polyethylene/Fe3O4 Nanoparticles for Remote Activation

    Directory of Open Access Journals (Sweden)

    Yongkun Wang

    2016-11-01

    Full Text Available Magnetically sensitive shape memory poly(styrene-b-butadiene-b-styrene copolymer (SBS/liner low density polyethylene (LLDPE composites filled with various contents of Fe3O4 nanoparticles were prepared. The influence of the Fe3O4 nanoparticles content on the thermal properties, mechanical properties, fracture morphology, magnetic behavior, and shape memory effect of SBS/LLDPE/Fe3O4 composites was systematically studied in this paper. The results indicated that homogeneously dispersed Fe3O4 nanoparticles ensured the uniform heat generation and transfer in the alternating magnetic field, and endowed the SBS/LLDPE/Fe3O4 composites with an excellent magnetically responsive shape memory effect. When the shape memory composites were in the alternating magnetic field (f = 60 kHz, H = 21.21 kA·m−1, the best shape recovery ratio reached 99%, the shape retention ratio reached 99.4%, and the shape recovery speed increased significantly with the increment of Fe3O4 nanoparticles. It is anticipated that tagging products with this novel shape memory composite is helpful for the purpose of an intravascular delivery system in Micro-Electro-Mechanical System (MEMS devices.

  8. 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.

  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. Synthesis, characterization and application of iron (II, III) oxide (Fe3O4) magnetic nanoparticles in mimic of wound healing model

    Science.gov (United States)

    Konyala, Divya

    The research study focused on synthesis, characterization and applications of Fe3O4 core-shelled magnetic nanomaterials. This Fe3O4 magnetic nanomaterials will be prepared by using cost effective and convenient wet-chemistry method and will encapsulated using aqueous extracts of medicinal natural products. Three natural products namely Symplocos racemosa, Picrorhiza kurroa and Butea monosperma used to encapsulate Fe3O 4 MNMs due to their scope to reduce the risk of cancer, improves health, increase energy and enhance the immunity. These three medicinal natural products are synthesize by using water as a solvents to derive its active constituents, which will further used to functionalize the magnetic nanomaterials. The magnetic nanoparticles characterization studies performed using X-ray powder diffraction, Scanning electron microscope, Transmission electron microscope, Ultraviolet-visible spectroscopy, Fourier Transform Infrared spectroscopy (FT-IR) and Magnetic property. Fe3O4 magnetic nanomaterials biological activity was tested on Gram-negative bacteria (Escherichia coli). The results pointed out that, due to the adequate coating of Fe 3O4 (Iron Oxide) core by the medicinal chemical constituents from the natural products, the absorption of Fe3O4 magnetic nanomaterials was not detected in the UV-VIS Spectroscopy. TEM images showed that Fe3O4 coated with natural product extract in core-shelled structure, and the size of the particle ranges from 6 nm to 10 nm. Fourier Transform Infrared spectroscopy (FT-IR) was performed to determine the nature of chemicals present in natural extracts and functionalized Fe3O 4 magnetic nanomaterials. The model of wound healing mimic and antibacterial activity performed on gram-negative (Escherichia coli), indicating steady increasing cell growth after adding Fe3O4 MNMs. It was also found that MNMs synthesized at high temperatures shows less wound healing activity, when compared to MNMs prepared at room temperature due to formation

  11. Facile self-assembly of Fe3O4 nanoparticles@WS2 nanosheets: A promising candidate for supercapacitor electrode

    Science.gov (United States)

    Dai, Yu; Wu, Xiao; Sha, Dawei; Chen, Ming; Zou, Han; Ren, Jie; Wang, Jingjing; Yan, Xuehua

    2016-10-01

    Graphene-like dichalcogenides with huge surface area and nanostructured transition metal oxides with extraordinarily high theoretical capacities could be composited as promising electrode candidates for supercapacitors. In this work, monolayer and few-layers WS2 nanosheets were exfoliated by combination of ball-milling and sonication. A facile strategy for the hierarchical self-assembly of Fe3O4 nanoparticles (Fe3O4NPs) on WS2 nanosheets was developed to synthesize Fe3O4NPs@WS2 nanocomposites via hydrothermal method. Fe3O4NPs are uniformly dispersed on the WS2 nanosheets without aggregation. The particle size of Fe3O4NPs is about 3 nm. The nanocomposite shows strong enhancements of electrochemical behaviors. This self-assembly synthesis strategy may have great prospects for other 0D/2D nanocomposites in supercapacitors and other energy devices. [Figure not available: see fulltext.

  12. 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.

  13. Use of aerosol route to fabricate positively charged Au/Fe3O4 Janus nanoparticles as multifunctional nanoplatforms

    Science.gov (United States)

    Byeon, Jeong Hoon; Park, Jae Hong

    2016-10-01

    Gold (Au)-decorated iron oxide (Fe3O4), Au/Fe3O4, Janus nanoparticles were fabricated via the continuous route for aerosol Au incorporation with Fe3O4 domains synthesized in an aqueous medium as multifunctional nanoplatforms. The fabricated nanoparticles were subsequently exposed to 185-nm UV light to generate positive charges on Au surfaces, and their activities were tested in computed tomography (CT) and magnetic resonance (MR) imaging, gene-delivery and photothermal therapy. No additional polymeric coatings of the Janus particles also had a unique ability to suppress inflammatory responses in macrophages challenged with lipopolysaccharide, which may be due to the absence of amine groups.

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

    OpenAIRE

    Bai, Xuekun; Mou, Chengbo; 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 transm...

  15. 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.

  16. Fluorescent magnetic Fe3 O4 /rare Earth colloidal nanoparticles for dual-modality imaging.

    Science.gov (United States)

    Zhu, Haie; Shang, Yalei; Wang, Wenhao; Zhou, Yingjie; Li, Penghui; Yan, Kai; Wu, Shuilin; Yeung, Kelvin W K; Xu, Zushun; Xu, Haibo; Chu, Paul K

    2013-09-09

    Fluorescent magnetic colloidal nanoparticles (FMCNPs) are produced by a two-step, seed emulsifier-free emulsion polymerization in the presence of oleic acid and sodium undecylenate-modified Fe3 O4 nanoparticles (NPs). The Fe3 O4 /poly(St-co-GMA) nanoparticles are first synthesized as the seed and Eu(AA)3 Phen is copolymerized with the remaining St and GMA to form the fluorescent polymer shell in the second step. The uniform core-shell structured FMCNPs with a mean diameter of 120 nm exhibit superparamagnetism with saturation magnetization of 1.92 emu/g. Red luminescence from the FMCNPs is confirmed by the salient fluorescence emission peaks of europium ions at 594 and 619 nm as well as 2-photon confocal scanning laser microscopy. The in vitro cytotoxicity test conducted using the MTT assay shows good cytocompatibility and the T2 relaxivity of the FMCNPs is 353.86 mM(-1) S(-1) suggesting its potential in magnetic resonance imaging (MRI). In vivo MRI studies based on a rat model show significantly enhanced T2 -weighted images of the liver after administration and prussian blue staining of the liver tissue slice reveals accumulation of FMCNPs in the organ. The cytocompatibility, superparamagnetism, and excellent fluorescent properties of FMCNPs make them suitable for biological imaging probes in MRI and optical imaging.

  17. 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.

  18. 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.

  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. 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

  1. Synthesis of Fe3O4 nanoparticles by wet milling iron powder in a planetary ball mill

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    Fe3O4 nanoparticles with sizes ranging from 30 to 80nm were synthesized by wet milling iron powders in a planetary ball mill. The phase composition and the morphologies of the as-synthesized products were measured by X-ray diffraction (XRD), scanning electron microscopy (SEM) and transmission electron microscopy (TEM). Nanosized Fe3O4 particles were prepared by wet milling metallic iron powder (-200 mesh, 99%)rotation speed of 300 rpm. The use of the iron balls in this method played a key role in Fe3O4 formation. The present technique is simple and the process is easy to carry out.

  2. 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.

  3. Fast defluorination and removal of norfloxacin by alginate/Fe@Fe3O4 core/shell structured nanoparticles.

    Science.gov (United States)

    Niu, Hongyun; Dizhang; Meng, Zhaofu; Cai, Yaqi

    2012-08-15

    Alginate-Fe(2+)/Fe(3+) polymer coated Fe(3)O(4) magnetic nanoparticles (Fe(3)O(4)@ALG/Fe MNPs) with core/shell structure are prepared and used as heterogeneous Fenton nanocatalyst to degrade norfloxacin (NOF). The Fenton-like process based on Fe(3)O(4)@ALG/Fe shows much higher efficiency on NOF degradation. Compared with Fe(3)O(4) nanoparticle-H(2)O(2) system, NOF degradation in Fe(3)O(4)@AlG/Fe-H(2)O(2) system can be conducted in a wide pH range (pH 3.5-6.5) and independent on temperature. With 0.98 mM H(2)O(2) and 0.4 g L(-1) Fe(3)O(4)@ALG/Fe, 100% of NOF and 90% of TOC is removed within 60 min, and the fluorine element in NOF molecule changes into F(-) ions within 1 min, indicating that NOF degradation in this Fenton-like reaction is performed through direct defluorination pathway. XPS analysis shows that TOC removal in reaction solution mainly results from the adsorption of NOF degradation intermediates on catalyst. Due to the paramagneticity and high saturation magnetization of Fe(3)O(4)@ALG/Fe, the used catalyst with adsorbed NOF intermediate is collected from aqueous solution by applying an external magnetic field, leading to complete removal of NOF from water samples. As being composed of inorganic materials and biopolymer, Fe(3)O(4)@ALG/Fe MNPs are robust, thermo-stable, nontoxic and environmentally friendly. These attractive features endow Fe(3)O(4)@ALG/Fe as a potent Fenton-like catalyst for fluoroquinolones degradation. Copyright © 2012 Elsevier B.V. All rights reserved.

  4. Fe3O4/salicylic acid nanoparticles versatility in magnetic mediated vascular nanoblockage

    Science.gov (United States)

    Mîndrilă, I.; Buteică, S. A.; Mihaiescu, D. E.; Badea, G.; Fudulu, A.; Mărgăritescu, D. N.

    2016-01-01

    An aqueous dispersion of Fe3O4/salicylic acid magnetic nanoparticles (SaMNPs) was synthesized by a modified Massart method, characterized by Inductively Coupled Plasma-Optic Emission Spectrometry (ICP-OES), High-Resolution Transmission Electron Microscopy (HRTEM) and Dynamic Light Scattering (DLS) methods, and tested on the chick chorioallantoic membrane (CAM) model to evaluate biocompatibility, biodistribution, intravascular time persistence, and ability to be magnetically target driven in order to block the blood supply into a tumor xenograft. ICP-OES, DLS, and HRTEM SaMNPs sample analyses showed a 0.356 mg/mL Fe concentration, a good stability in water (average Zeta potential of 39.3 mV), a hydrodynamic diameter around 52 nm and a core diameter in the 7-15 nm range for the Fe3O4 nanoparticles. In vivo CAM assay showed that SaMNPs were biocompatible with the chick embryo, were fixed almost completely by the liver, had no embolic potential, and a threshold-dose-dependent intravascular magnetic targeting time. Study on the CAM tumor model showed that SaMNPs could be used for long-term magnetically mediated nanoblocking of the capillary networks and 70-µm smaller arterioles.

  5. 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

  6. Preparation of stable magnetic nanofluids containing Fe3O4@PPy nanoparticles by a novel one-pot route

    Directory of Open Access Journals (Sweden)

    Zhao Baobao

    2011-01-01

    Full Text Available Abstract Stable magnetic nanofluids containing Fe3O4@Polypyrrole (PPy nanoparticles (NPs were prepared by using a facile and novel method, in which one-pot route was used. FeCl3·6H2O was applied as the iron source, and the oxidizing agent to produce PPy. Trisodium citrate (Na3cit was used as the reducing reagent to form Fe3O4 NPs. The as-prepared nanofluid can keep long-term stability. The Fe3O4@PPy NPs can still keep dispersing well after the nanofluid has been standing for 1 month and no sedimentation is found. The polymerization reaction of the pyrrole monomers took place with Fe3+ ions as the initiator, in which these Fe3+ ions remained in the solution adsorbed on the surface of the Fe3O4 NPs. Thus, the core-shell NPs of Fe3O4@PPy were obtained. The particle size of the as-prepared Fe3O4@PPy can be easily controlled from 7 to 30 nm by the polymerization reaction of the pyrrole monomers. The steric stabilization and weight of the NPs affect the stability of the nanofluids. The as-prepared Fe3O4@PPy NPs exhibit superparamagnetic behavior.

  7. 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.

  8. 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

  9. Green synthesis of magnetite (Fe3O4) nanoparticles using Graptophyllum pictum leaf aqueous extract

    Science.gov (United States)

    Sari, I. P.; Yulizar, Y.

    2017-04-01

    Magnetite nanoparticles (MNPs) attracted the attention of many researchers due to their unique properties. In this research, nanoscale magnetite particles have been successfully synthesized through an environmentally friendly method using aqueous extract of Graptophyllum pictum leaf (GPLE). In MNPs formation, GPLE acted as a base source and capping agent. Alkaloids in GPLE were hydrolyzed in water and hydroxilated Fe2+ to form Fe3O4 nanoparticles powder through calcination. After the addition of leaf extract, MNPs formation was observed by color change from pale yellow to dark brown. The synthesized nanoparticles were characterized using UV-Vis spectrophotometer, X-Ray diffraction (XRD), and Fourier transform infra red (FTIR) spectroscopy. The results confirmed that MNPs formation indicated the surface plasmon resonance at a maximum wavelength, λmax 291 nm. The average crystallite size is 23.17 nm. The formed MNPs through green synthesis method promise in various medical applications such as drug carrier and targeted therapy.

  10. Fe3O4-based PLGA nanoparticles as MR contrast agents for the detection of thrombosis

    Science.gov (United States)

    Liu, Jia; Xu, Jie; Zhou, Jun; Zhang, Yu; Guo, Dajing; Wang, Zhigang

    2017-01-01

    Thrombotic disease is a great threat to human health, and early detection is particularly important. Magnetic resonance (MR) molecular imaging provides noninvasive imaging with the potential for early disease diagnosis. In this study, we developed Fe3O4-based poly(lactic-co-glycolic acid) (PLGA) nanoparticles (NPs) surface-modified with a cyclic Arg-Gly-Asp (cRGD) peptide as an MR contrast agent for the detection of thrombosis. The physical and chemical characteristics, biological toxicity, ability to target thrombi, and biodistribution of the NPs were studied. The Fe3O4-PLGA-cRGD NPs were constructed successfully, and hematologic and pathologic assays indicated no in vivo toxicity of the NPs. In a rat model of FeCl3-induced abdominal aorta thrombosis, the NPs readily and selectively accumulated on the surface of the thrombosis and under vascular endothelial cells ex vivo and in vivo. In the in vivo experiment, the biodistribution of the NPs suggested that the NPs might be internalized by the macrophages of the reticuloendothelial system in the liver and the spleen. The T2 signal decreased at the mural thrombus 10 min after injection and then gradually increased until 50 min. These results suggest that the NPs are suitable for in vivo molecular imaging of thrombosis under high shear stress conditions and represent a very promising MR contrast agent for sensitive and specific detection of thrombosis. PMID:28223802

  11. 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.

  12. Facile synthesis and characterization of magnetochromatic Fe3O4 nanoparticles

    Science.gov (United States)

    Wang, Wei; Zheng, Lelin; Lu, Fenghua; Hong, Ruijiang; Chen, Michael Z. Q.; Zhuang, Lin

    2017-05-01

    A facile synthetic method for magnetochromatic Fe3O4 nanoparticles (FNPs) with controllable size and optical properties has been fabricated by the combination of an improved solvothermal method and the usage of ultrasonic irradiation in the surface modification step. The improved solvothermal method enables the alteration of the size of nanoparticles (50nm to 180nm) in a competitively convenient way by adjusting the ratio of binary solvents, including diethylene glycol (DEG) and ethylene glycol (EG). In the surface modification step, the short-chain polyacrylic acid (PAA) is added as the surfactant with ultrasound-assisted method. In this research, due to magnetically-driven assembly FNPs forming photonic crystals, the reflection peaks show blue-shift as the magnetic field is increased from 181 to 2479G. In addition, on the basis of the calculation using Bragg's Law, the thickness of the solvent layer is measured approximately 35nm, which accounts for the magnetochromatic properties as well as excellent dispersion.

  13. Core-shell Fe3O4 polydopamine nanoparticles serve multipurpose as drug carrier, catalyst support and carbon adsorbent.

    Science.gov (United States)

    Liu, Rui; Guo, Yunlong; Odusote, Gloria; Qu, Fengli; Priestley, Rodney D

    2013-09-25

    We present the synthesis and multifunctional utilization of core-shell Fe3O4 polydopamine nanoparticles (Fe3O4@PDA NPs) to serve as the enabling platform for a range of applications including responsive drug delivery, recyclable catalyst support, and adsorbent. Magnetite Fe3O4 NPs formed in a one-pot process by the hydrothermal approach were coated with a polydopamine shell layer of ~20 nm in thickness. The as prepared Fe3O4@PDA NPs were used for the controlled drug release in a pH-sensitive manner via reversible bonding between catechol and boronic acid groups of PDA and the anticancer drug bortezomib (BTZ), respectively. The facile deposition of Au NPs atop Fe3O4@PDA NPs was achieved by utilizing PDA as both the reducing agent and the coupling agent. The nanocatalysts exhibited high catalytic performance for the reduction of o-nitrophenol. Furthermore, the recovery and reuse of the catalyst was demonstrated 10 times without any detectible loss in activity. Finally, the PDA layers were converted into carbon to obtain Fe3O4@C and used as an adsorbent for the removal of Rhodamine B from an aqueous solution. The synergistic combination of unique features of PDA and magnetic nanoparticles establishes these core-shell NPs as a versatile platform for multiple applications.

  14. Experimental study of fundamental mechanisms in inductive heating of ferromagnetic nanoparticles suspension (Fe3O4 Iron Oxide Ferrofluid)

    Science.gov (United States)

    Li, Calvin H.; Hodgins, Paul; Peterson, G. P.

    2011-09-01

    An experimental investigation of the initial heating rate of 50 nm ferromagnetic nanoparticles (Fe3O4) suspended in water and incorporated in an agar gel was conducted to study the thermal heating effects resulting from Brownian motion and hysteresis losses. Particles were placed in an alternating current magnetic field with intensities of 28.6, 35.8, 38.9, and 43.0 kA m-1, at frequencies ranging from 161 to 284 kHz. The specific absorption rate based on the heating rate was calculated and the contributions from the Brownian motion and hysteresis losses are compared and analyzed.

  15. Synthesis, Properties and Application of Glucose Coated Fe3O4 Nanoparticles Prepared by Co-precipitation Method

    Science.gov (United States)

    Sari, Ayu Y.; Eko, A. S.; Candra, K.; Hasibuan, Denny P.; Ginting, M.; Sebayang, P.; Simamora, P.

    2017-07-01

    Synthesis of glucose coated Fe3O4 magnetic nanoparticles have been successfully prepared with co-precipitation method. Raw material of natural iron-sand was obtained from Buaya River, Deliserdang, Indonesia. The milled iron-sand was dissolved in HCl (37 mole %), and stirred in 300 rpm at 70°C for 90 minutes. Glucose was added to the filtered powder with varied content of 0.01, 0.02, and 0.03 mole, and precipitated by NH3 (25 mole%). After drying process, the final product subsequently was glucose coated magnetite (Fe3O4) nanoparticles. The characterizations performed were true density measurement, FTIR, VSM, XRD, BET, and adsorbent performance by AAS. The FTIR analysis showed that M-O (bending) with M=Fe (stretching vibration) with υ = 570.92 and 401.19 cm-1. While glucose coated well on nanoparticle Fe3O4, proved by functional groups C=O (stretching), M-O (stretching) and C-H (bending) with υ = 1404.17, 570.92, and 2368.58 cm-1, respectively. Single phase of magnetite (Fe3O4) structure was determined from XRD analysis with cubic spinel structure and lattice parameter of 8.396 Å. The optimum conditions, obtained on the Fe3O4 nanoparticles with 0.01 mole of glucose addition, which has true density value of 4.57 g/cm3, magnetic saturation, M s = 35,41 emu/g, coercivity, H cJ = 83.58 Oe, average particle size = 12.3 nm and surface area = 124.88 m2/g. This type magnetic nanoparticles of glucose-coated Fe3O4 was capable to adsorbed 93.78 % of ion Pb. Therefore, the glucose-coated Fe3O4 nanoparticle is a potential candidate to be used as heavy metal removal from wastewater.

  16. 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.

  17. 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.

  18. Fe3O4 nanoparticles on graphene oxide sheets for isolation and ultrasensitive amperometric detection of cancer biomarker proteins.

    Science.gov (United States)

    Sharafeldin, Mohamed; Bishop, Gregory W; Bhakta, Snehasis; El-Sawy, Abdelhamid; Suib, Steven L; Rusling, James F

    2017-05-15

    Ultrasensitive mediator-free electrochemical detection for biomarker proteins was achieved at low cost using a novel composite of Fe3O4 nanoparticles loaded onto graphene oxide (GO) nano-sheets (Fe3O4@GO). This paramagnetic Fe3O4@GO composite (1µm size range) was decorated with antibodies against prostate specific antigen (PSA) and prostate specific membrane antigen (PSMA), and then used to first capture these biomarkers and then deliver them to an 8-sensor detection chamber of a microfluidic immunoarray. Screen-printed carbon sensors coated with electrochemically reduced graphene oxide (ERGO) and a second set of antibodies selectively capture the biomarker-laden Fe3O4@GO particles, which subsequently catalyze hydrogen peroxide reduction to detect PSA and PSMA. Accuracy was confirmed by good correlation between patient serum assays and enzyme-linked immuno-sorbent assays (ELISA). Excellent detection limits (LOD) of 15 fg/mL for PSA and 4.8 fg/mL for PSMA were achieved in serum. The LOD for PSA was 1000-fold better than the only previous report of PSA detection using Fe3O4. Dynamic ranges were easily tunable for concentration ranges encountered in serum samples by adjusting the Fe3O4@GO Concentration. Reagent cost was only $0.85 for a single 2-protein assay.

  19. High surface area monodispersed Fe3O4 nanoparticles alone and on physical exfoliated graphite for improved supercapacitors

    Science.gov (United States)

    Sarno, Maria; Ponticorvo, Eleonora; Cirillo, Claudia

    2016-12-01

    Highly conductive, unsophisticated and easy to be obtained physical exfoliated graphite (PHG) supporting well dispersed magnetite, Fe3O4/PHG nanocomposite, has been prepared by a one-step chemical strategy and physico-chemical characterized. The nanocomposite, favoured by the a-polar nanoparticles (NPs) capping, results in a self-assembled monolayer of monodispersed Fe3O4, covering perfectly the hydrophobic surfaces of PHG. The nanocomposite as an electrode material was fabricated into a supercapacitor and characterized by cyclic voltammetry (CV) and galvanostatic charge-discharge measurements. It shows, after a suitable annealing, significant electrochemical properties (capacitance value of 787 F/g at 0.5 A g-1 and a Fe3O4/PHG weight ratio of 0.31) and good cycling stability (retention 91% after 30,000 cycles). Highly monodispersed very fine Fe3O4 NPs, covered by organic chains, have been also synthesized. The high surface area Fe3O4 NPs, after washing to leave a low content of organic chains able to avoid aggregation without excessively affecting the electrical properties of the material, exhibit remarkable pseudocapacitive activities, including the highest specific capacitance over reported for Fe3O4 (300 F/g at 0.5 A g-1).

  20. 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.

  1. Fe3O4-based PLGA nanoparticles as MR contrast agents for the detection of thrombosis

    Directory of Open Access Journals (Sweden)

    Liu J

    2017-02-01

    Full Text Available Jia Liu,1 Jie Xu,1 Jun Zhou,1 Yu Zhang,1 Dajing Guo,1 Zhigang Wang2 1Department of Radiology, 2Department of Ultrasound, Institute of Ultrasound Imaging, The Second Affiliated Hospital of Chongqing Medical University, Yuzhong, Chongqing, People’s Republic of China Abstract: Thrombotic disease is a great threat to human health, and early detection is particularly important. Magnetic resonance (MR molecular imaging provides noninvasive imaging with the potential for early disease diagnosis. In this study, we developed Fe3O4-based poly(lactic-co-glycolic acid (PLGA nanoparticles (NPs surface-modified with a cyclic Arg-Gly-Asp (cRGD peptide as an MR contrast agent for the detection of thrombosis. The physical and chemical characteristics, biological toxicity, ability to target thrombi, and biodistribution of the NPs were studied. The Fe3O4-PLGA-cRGD NPs were constructed successfully, and hematologic and pathologic assays indicated no in vivo toxicity of the NPs. In a rat model of FeCl3-induced abdominal aorta thrombosis, the NPs readily and selectively accumulated on the surface of the thrombosis and under vascular endothelial cells ex vivo and in vivo. In the in vivo experiment, the biodistribution of the NPs suggested that the NPs might be internalized by the macrophages of the reticuloendothelial system in the liver and the spleen. The T2 signal decreased at the mural thrombus 10 min after injection and then gradually increased until 50 min. These results suggest that the NPs are suitable for in vivo molecular imaging of thrombosis under high shear stress conditions and represent a very promising MR contrast agent for sensitive and specific detection of thrombosis. Keywords: iron oxide, poly(lactic-co-glycolic acid, thrombosis, magnetic resonance imaging, cyclic Arg-Gly-Asp peptide

  2. Novel electrochemical sensor based on N-doped carbon nanotubes and Fe3O4 nanoparticles: simultaneous voltammetric determination of ascorbic acid, dopamine and uric acid.

    Science.gov (United States)

    Fernandes, Diana M; Costa, Marta; Pereira, Clara; Bachiller-Baeza, Belén; Rodríguez-Ramos, Inmaculada; Guerrero-Ruiz, Antonio; Freire, Cristina

    2014-10-15

    A new modified electrode based on N-doped carbon nanotubes functionalized with Fe3O4 nanoparticles (Fe3O4@CNT-N) has been prepared and applied on the simultaneous electrochemical determination of small biomolecules such as dopamine (DA), uric acid (UA) and ascorbic acid (AA) using voltammetric methods. The unique properties of CNT-N and Fe3O4 nanoparticles individually and the synergetic effect between them led to an improved electrocatalytic activity toward the oxidation of AA, DA and UA. The overlapping anodic peaks of these three biomolecules could be resolved from each other due to their lower oxidation potentials and enhanced oxidation currents when using the Fe3O4@CNT-N modified electrode. The linear response ranges for the square wave voltammetric determination of AA, DA and UA were 5-235, 2.5-65 and 2.5-85μmoldm(-3) with detection limit (S/N=3) of 0.24, 0.050 and 0.047μmoldm(-3), respectively. These results show that Fe3O4@CNT-N nanocomposite is a promising candidate of cutting-edge electrode materials for electrocatalytic applications.

  3. 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。

  4. Radiolytic formation of Fe3O4 nanoparticles: influence of radiation dose on structure and magnetic properties.

    Directory of Open Access Journals (Sweden)

    Alam Abedini

    Full Text Available Colloidal Fe3O4 nanoparticles were synthesized using a gamma-radiolysis method in an aqueous solution containing iron chloride in presence of polyvinyl alcohol and isopropanol as colloidal stabilizer and hydroxyl radical scavenger, respectively. Gamma irradiation was carried out in a 60Co gamma source chamber at different absorbed doses. Increasing the radiation dose above a certain critical dose (100 kGy leads to particle agglomeration enhancement, and this can influence the structure and crystallinity, and consequently the magnetic properties of the resultant particles. The optimal condition for formation of Fe3O4 nanoparticles with a uniform and narrow size distribution occurred at a dose of 100 kGy, as confirmed by X-ray diffractometry and transmission electron microscopy. A vibrating sample magnetometry study showed that, when radiation dose increased, the saturation and remanence magnetization decreased, whereas the coercivity and the remanence ratio increased. This magnetic behavior results from variations in crystallinity, surface effects, and particle size effects, which are all dependent on the radiation dose. In addition, Fourier transform infrared spectroscopy was performed to investigate the nature of the bonds formed between the polymer chains and the metal surface at different radiation doses.

  5. Degradation of methylene blue with H2O2 activated by peroxidase-like Fe3O4 magnetic nanoparticles.

    Science.gov (United States)

    Jiang, Jizhou; Zou, Jing; Zhu, Lihua; Huang, Lei; Jiang, Haipeng; Zhang, Yuanxiao

    2011-06-01

    Fe3O4 magnetic nanoparticles (Fe3O4 MNPs) were successfully prepared through an advanced reverse co-precipitation method under the assistance of ultrasound irradiation. The structure and size distribution were characterized by X-ray powder diffraction (XRD), laser particle size analyzer (LPSA), Fourier transform infrared spectroscopy (FT-IR) and Raman spectroscopy. The magnetic properties of Fe3O4 nanoparticles were measured by the vibrating sample magnetometer (VSM). Such Fe3O4 MNPs were used as a peroxidase mimetic to remove the dye pollutant methylene blue (MB) in the presence of H2O2. Some important reaction parameters were optimized to improve the degradation of MB. It was observed that the degradation efficiency of 10 mg L(-1) MB was above 96% over 0.62 g L(-1) Fe3O4 MNPs within 0.30 mmol L(-1) H2O2 at pH 4.85 and temperature 25 degrees C in 15 min, being superior to the previous reports.

  6. 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.

  7. Synthesis of Fe3O4@phenol formaldehyde resin core-shell nanospheres loaded with Au nanoparticles as magnetic FRET nanoprobes for detection of thiols in living cells.

    Science.gov (United States)

    Yang, Ping; Xu, Qi-Zhi; Jin, Sheng-Yu; Zhao, Yang; Lu, Yang; Xu, Xue-Wei; Yu, Shu-Hong

    2012-01-23

    A magnetic, sensitive, and selective fluorescence resonance energy transfer (FRET) probe for detection of thiols in living cells was designed and prepared. The FRET probe consists of an Fe(3)O(4) core, a green-luminescent phenol formaldehyde resin (PFR) shell, and Au nanoparticles (NPs) as FRET quenching agent on the surface of the PFR shell. The Fe(3)O(4) NPs were used as the core and coated with green-luminescent PFR nanoshells by a simple hydrothermal approach. Au NPs were then loaded onto the surface of the PFR shell by electric charge absorption between Fe(3)O(4)@PFR and Au NPs after modifying the Fe(3)O(4)@PFR nanocomposites with polymers to alter the charge of the PFR shell. Thus, a FRET probe can be designed on the basis of the quenching effect of Au NPs on the fluorescence of Fe(3)O(4)@PFR nanocomposites. This magnetic and sensitive FRET probe was used to detect three kinds of primary biological thiols (glutathione, homocysteine, and cysteine) in cells. Such a multifunctional fluorescent probe shows advantages of strong magnetism for sample separation, sensitive response for sample detection, and low toxicity without injury to cellular components.

  8. Amphiphilic comblike polymers enhance the colloidal stability of Fe(3)O(4) nanoparticles.

    Science.gov (United States)

    Kim, Myeongjin; Jung, Jaeyeon; Lee, Jonghwan; Na, Kyunga; Park, Subeom; Hyun, Jinho

    2010-03-01

    Stable colloidal dispersions of magnetite (Fe(3)O(4)) nanoparticles (MNPs) were obtained with the inclusion of an amphiphilic comblike polyethylene glycol derivative (CL-PEG) as an amphiphilic polymeric surfactant. Both the size and morphology of the resulting CL-PEG-modified MNPs could be controlled and were characterized by transmission electron microscopy (TEM). The interaction between MNPs and CL-PEG was confirmed by the presence of characteristic infrared absorption peaks, and the colloidal stability of the nanoparticle dispersion in water was evaluated by long-term observation of the dispersion using UV-visible spectroscopy. SQUID measurements confirmed the magnetization of CL-PEG-modified MNPs. The zeta potential of the CL-PEG-modified MNPs showed a dramatic conversion from positive to negative in response to the pH of the surrounding aqueous medium due to the presence of carboxyl groups at the surface. These carboxyl groups can be used to functionalize the MNPs with biomolecules for biotechnological applications. However, regardless of surface electrostatics, the flexible, hydrophilic side chains of CL-PEG-modified MNPs prevented the approach of adjacent nanoparticles, thereby resisting aggregation and resulting in a stable aqueous colloid. The cytotoxicity of MNPs and CL-PEG-modified MNPs was evaluated by a MTT assay.

  9. Coupling Hollow Fe3O4-Fe Nanoparticles with Graphene Sheets for High-Performance Electromagnetic Wave Absorbing Material.

    Science.gov (United States)

    Qu, Bin; Zhu, Chunling; Li, Chunyan; Zhang, Xitian; Chen, Yujin

    2016-02-17

    We developed a strategy for coupling hollow Fe3O4-Fe nanoparticles with graphene sheets for high-performance electromagnetic wave absorbing material. The hollow Fe3O4-Fe nanoparticles with average diameter and shell thickness of 20 and 8 nm, respectively, were uniformly anchored on the graphene sheets without obvious aggregation. The minimal reflection loss RL values of the composite could reach -30 dB at the absorber thickness ranging from 2.0 to 5.0 mm, greatly superior to the solid Fe3O4-Fe/G composite and most magnetic EM wave absorbing materials recently reported. Moreover, the addition amount of the composite into paraffin matrix was only 18 wt %.

  10. 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.

  11. EDTA-Coated Fe3O4 Nanoparticles: a Novel Biocompatible Fertilizer for Improving Agronomic Traits of Sunflower (Helianthus Annuus

    Directory of Open Access Journals (Sweden)

    M. Shahrekizad

    2015-04-01

    Full Text Available In this study, a set of experiments were conducted to investigate the influence of EDTA-grafted iron oxide nanoparticles exposure on agronomic traits of sunflower (Helianthus annuus plants. The experiment was implemented by applying Nano-Fe3O4-EDTA and Fe-EDTA fertilizers applied through spray or soil amendment. A variety of parameters including Aerial organ biomass, Number of leaves, Plant height, Chlorophyll content as well as elemental quantities of the plants were investigated. The results demonstrated considerably dominant effect of Nano-Fe3O4-EDTA fertilizer on many of the studied factors. The dramatically increased Fe content of plants (137% relative to the control by using nano-Fe-EDTA, makes this novel fertilizer a promising candidate to obviate iron deficiency problem in plants. Moreover, it was clearly observed that more pronounced positive effects is obtained through soil amendment than by foliar application of fertilizers and only in some cases such as aerial organ biomasses and Fe content, the foliar treatment has turned out to be more effective.

  12. Influence of different synthesis conditions on properties of oleic acid-coated-Fe3O4 nanoparticles

    Directory of Open Access Journals (Sweden)

    Aliakbari Atieh

    2015-03-01

    Full Text Available In the present paper, iron oxide nanoparticles coated by oleic acid have been synthesized in different conditions by coprecipitation method. For investigating the effect of time spent on adding the oleic acid to the precursor solution, two different processes have been considered. The as synthesized samples were characterized by X-ray diffraction (XRD, transmission electron microscopy (TEM and Fourier transform infrared spectroscopy (FT-IR. Magnetic measurement was carried out at room temperature using a vibrating sample magnetometer (VSM. The results show that the magnetic nanoparticles decorated with oleic acid decreased the saturation of magnetization. From the data, it can also be concluded that the magnetization of Fe3O4/oleic acid nanoparticles depends on synthesis conditions.

  13. Removal of silver nanoparticles by mussel-inspired Fe3O4@ polydopamine core-shell microspheres and its use as efficient catalyst for methylene blue reduction

    OpenAIRE

    Maoling Wu; Yinying Li; Rui Yue; Xiaodan Zhang; Yuming Huang

    2017-01-01

    The removal of silver nanoparticles (AgNPs) from water is highly needed because of their increasing use and potential risk to the environment due to their toxic effects. Catalysis over AgNPs has received significant attention because of their highly catalytic performance. However, their use in practical applications is limited due to high cost and limited resources. Here, we present for the first time that the mussel-inspired Fe3O4@polydopamine (Fe3O4@PDA) nanocomposite can be used for effici...

  14. Healing of Early Stage Fatigue Damage in Ionomer/Fe3O4 Nanoparticle Composites

    Directory of Open Access Journals (Sweden)

    Wouter Post

    2016-12-01

    Full Text Available This work reports on the healing of early stage fatigue damage in ionomer/nano-particulate composites. A series of poly(ethylene-co-methacrylic acid zinc ionomer/Fe3O4 nanoparticle composites with varying amounts of ionic clusters were developed and subjected to different levels of fatigue loading. The initiated damage was healed upon localized inductive heating of the embedded nanoparticles by exposure of the particulate composite to an alternating magnetic field. It is here demonstrated that healing of this early stage damage in ionomer particulate composites occurs in two different steps. First, the deformation is restored by the free-shrinkage of the polymer at temperatures below the melt temperature. At these temperatures, the polymer network is recovered thereby resetting the fatigue induced strain hardening. Then, at temperatures above the melting point of the polymer phase, fatigue-induced microcracks are sealed, hereby preventing crack propagation upon further loading. It is shown that the thermally induced free-shrinkage of these polymers does not depend on the presence of ionic clusters, but that the ability to heal cracks by localized melting while maintaining sufficient mechanical integrity is reserved for ionomers that contain a sufficient amount of ionic clusters guaranteeing an acceptable level of mechanical stability during healing.

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

    Science.gov (United States)

    Zhang, Zhengyong; Kong, Jilie

    2011-10-15

    The magnetic Fe(3)O(4)/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 Fe(3)O(4)/C complex nanomaterials could thus be used as promising adsorbents for the remove organic dyes, especially, cationic dye, from polluted water.

  16. 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

  17. 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

  18. Co-adsorption of gaseous benzene, toluene, ethylbenzene, m-xylene (BTEX) and SO2 on recyclable Fe3O4 nanoparticles at 0-101% relative humidities.

    Science.gov (United States)

    Ye, Connie Z; Ariya, Parisa A

    2015-05-01

    We herein used Fe3O4 nanoparticles (NPs) as an adsorption interface for the concurrent removal of gaseous benzene, toluene, ethylbenzene and m-xylene (BTEX) and sulfur dioxide (SO2), at different relative humidities (RH). X-ray diffraction, Brunauer-Emmett-Teller, and transmission electron microscopy were deployed for nanoparticle surface characterization. Mono-dispersed Fe3O4 (Fe2O3·FeO) NPs synthesized with oleic acid (OA) as surfactant, and uncoated poly-dispersed Fe3O4 NPs demonstrated comparable removal efficiencies. Adsorption experiments of BTEX on NPs were measured using gas chromatography equipped with flame ionization detection, which indicated high removal efficiencies (up to (95±2)%) under dry conditions. The humidity effect and competitive adsorption were investigated using toluene as a model compound. It was observed that the removal efficiencies decreased as a function of the increase in RH, yet, under our experimental conditions, we observed (40±4)% toluene removal at supersaturation for Fe3O4 NPs, and toluene removal of (83±4)% to (59±6)%, for OA-Fe3O4 NPs. In the presence of SO2, the toluene uptake was reduced under dry conditions to (89±2)% and (75±1)% for the uncoated and coated NPs, respectively, depicting competitive adsorption. At RH>100%, competitive adsorption reduced the removal efficiency to (27±1)% for uncoated NPs whereas OA-Fe3O4 NPs exhibited moderate efficiency loss of (55±2)% at supersaturation. Results point to heterogeneous water coverage on the NP surface. The magnetic property of magnetite facilitated the recovery of both types of NPs, without the loss in efficiency when recycled and reused. Copyright © 2015. Published by Elsevier B.V.

  19. 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.

  20. 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.

  1. 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.

  2. Magnetic Fe3O4@C nanoparticles as adsorbents for removal of amoxicillin from aqueous solution.

    Science.gov (United States)

    Kakavandi, Babak; Esrafili, Ali; Mohseni-Bandpi, Anoushiravan; Jonidi Jafari, Ahmad; Rezaei Kalantary, Roshanak

    2014-01-01

    In the present study, powder activated carbon (PAC) combined with Fe(3)O(4) magnetite nanoparticles (MNPs) were used for the preparation of magnetic composites (MNPs-PAC), which was used as an adsorbent for amoxicillin (AMX) removal. The properties of magnetic activated carbon were characterized by scanning electron microscopy, transmission electron microscopy, X-ray diffraction, Brunaeur, Emmett and Teller and vibrating sample magnetometer. The operational factors affecting adsorption such as pH, contact time, adsorbent dosage, initial AMX concentration and temperature were studied in detail. The high surface area and saturation magnetization for the synthesized adsorbent were found to be 671.2 m(2)/g and 6.94 emu/g, respectively. The equilibrium time of the adsorption process was 90 min. Studies of adsorption equilibrium and kinetic models revealed that the adsorption of AMX onto MNPs-PAC followed Freundlich and Langmuir isotherms and pseudo-second-order kinetic models. The calculated values of the thermodynamic parameters, such as ΔG°, ΔH° and ΔS° demonstrated that the AMX adsorption was endothermic and spontaneous in nature. It could be concluded that MNPs-PAC have a great potential for antibiotic removal from aquatic media.

  3. Core/shell Fe3O4/BiOI nanoparticles with high photocatalytic activity and stability

    Science.gov (United States)

    Zheng, Liyun; Wang, Shuling; Zhao, Lixin; Zhao, Shuguo

    2016-11-01

    Core/shell Fe3O4/BiOI nanoparticles with BiOI sheath have been synthesized by a solvothermal reaction method and were characterized by transmission electron microscopy (TEM) with an energy dispersive spectrum (EDS), high-resolution TEM and X-ray diffraction (XRD). Their photocatalytic activities were evaluated by methylene blue (MB) under the simulated solar light. The results indicate that the spherical Fe3O4 particles were coated with BiOI sheath when the sample were synthesized at 160 °C with ethylene glycol and deionized water, forming a core/shell structure. The degradation rate of MB assisted with the core/shell Fe3O4/BiOI catalysts reached 98 % after 40-min irradiation. The catalytic performance enhancement of the core/shell Fe3O4/BiOI catalysts mainly attributes to the band structure that can improve the generation efficiency, separation and transfer process of the photo-induced electron-hole pairs and decrease their recombination. The magnetic Fe3O4 core not only contributes to the efficient separation of electron and holes, but also helps catalysts be collected conveniently using a magnet for reuse. After five repeated trials, the degradation rate of MB still maintains over 90 % and the saturated magnetization of the catalysts remains 51.5 emu/g, which indicate that the core/shell Fe3O4/BiOI nanoparticles have excellent photocatalytic stability and are recyclable for decomposing organic pollutants under visible light irradiation.

  4. 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.

  5. Application of Scallop shell-Fe3O4 nanoparticles for the removal of Cr(VI) from aqueous solutions.

    Science.gov (United States)

    Mohagheghian, Azita; Vahidi-Kolur, Robabeh; Pourmohseni, Melina; Yang, Jae-Kyu; Shirzad-Siboni, Mehdi

    2017-05-01

    In this study, removal of Cr(VI) by Scallop shell-Fe3O4 nanoparticles was investigated with variation of pH, adsorbent dosage, initial Cr(VI) concentration, ionic strength and temperature. Coating of Fe3O4 nanoparticles onto Scallop shell was identified by Fourier transform infrared spectroscopy, X-ray diffraction, scanning electron microscopy and energy dispersive X-ray analysis. The maximum adsorption was observed at pH 3. Removal efficiency of Cr(VI) was increased with increasing adsorbent dosage, but was decreased with increasing initial Cr(VI) concentration and temperature. Removal efficiency of Cr(VI) was decreased in the presence of sulfate and carbonate ions. Adsorption kinetic study revealed that a pseudo-second order model better described the removal data than a pseudo-first order model and an intra-particle diffusion model. Maximum adsorption capacity was estimated to be 34.48 mg/g. Thermodynamic studies indicated that adsorption of Cr(VI) onto Scallop shell-Fe3O4 nanoparticles occurred via an exothermic (ΔH = -320.88 KJ mol(-1)) process. Adsorption efficiency of Cr(VI) by Scallop shell-Fe3O4 nanoparticles was maintained even after eight successive cycles.

  6. 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

  7. 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

  8. 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.

  9. The changes of T lymphocytes and cytokines in ICR mice fed with Fe3O4 magnetic nanoparticles

    Directory of Open Access Journals (Sweden)

    Wang J

    2011-04-01

    Full Text Available Jun Wang1, Baoan Chen1, Nan Jin1, Guohua Xia2, Yue Chen1, Ying Zhou1, Xiaohui Cai1,2, Jiahua Ding1, Xiaomao Li3, Xuemei Wang41Department of Hematology, Zhongda Hospital, 2Department of Medical Laboratory, Medical School, Southeast University, Nanjing, People's Republic of China; 3Department of Physics, University of Saarland, Saarbruecken, Germany; 4National Key Laboratory of Bioelectronics (Chien-Shiung Wu Laboratory, Southeast University, Nanjing, People’s Republic of ChinaAbstract: The aim of this article is to study the changes inhibited T lymphocytes and cytokines related to the cellular immunity in ICR (imprinting control region mice fed with Fe3O4 magnetic nanoparticles (Fe3O4-MNPs. The Fe3O4-MNPs were synthesized, and their characteristics such as particle size, zeta potential, and X-ray diffraction patterns were measured and determined. All ICR mice were sacrificed after being exposed to 0, 300, 600, and 1200 mg/kg of Fe3O4-MNPs by single gastric administration for 14 days. Splenocytes proliferation was indicated with stimulate index by MTT assay; release of cytokines in the serum of ICR mice was detected by enzyme-linked immunosorbent assay, and the phenotypic analyses of T-lymphocyte subsets were performed using flow cytometry. Our results indicated that there were no significant differences in splenocyte proliferation and release of cytokines between exposed and control groups. Furthermore, there was no significant difference in the proportions of T-lymphocyte subsets in the low-dose Fe3O4-MNPs group when compared to the control group, but the proportions of CD3+CD4+ and CD3+CD8+ T-lymphocyte subsets both in the medium- and high-dose Fe3O4-MNPs groups were higher than those in the control group. It is concluded that a high dose of Fe3O4-MNPs, to some extent, could influence in vivo immune function of normal ICR mice.Keywords: Fe3O4, magnetic nanoparticles, splenocyte proliferation, release of cytokines, T-lymphocyte subsets, ICR

  10. Removal of silver nanoparticles by mussel-inspired Fe3O4@ polydopamine core-shell microspheres and its use as efficient catalyst for methylene blue reduction

    Science.gov (United States)

    Wu, Maoling; Li, Yinying; Yue, Rui; Zhang, Xiaodan; Huang, Yuming

    2017-02-01

    The removal of silver nanoparticles (AgNPs) from water is highly needed because of their increasing use and potential risk to the environment due to their toxic effects. Catalysis over AgNPs has received significant attention because of their highly catalytic performance. However, their use in practical applications is limited due to high cost and limited resources. Here, we present for the first time that the mussel-inspired Fe3O4@polydopamine (Fe3O4@PDA) nanocomposite can be used for efficient removal and recovery of AgNPs. Adsorption of AgNPs over Fe3O4@PDA was confirmed by TEM, FT-IR, XRD, TGA and magnetic property. The adsorption efficiency of AgNPs by Fe3O4@PDA was investigated as a function of pH, contact time, ionic strength and concentration of AgNPs. The kinetic data were well fitted to a pseudo-second order kinetic model. The isotherm data were well described by Langmuir model with a maximum adsorption capacity of 169.5 mg/g, which was higher than those by other adsorbents. Notably, the obtained AgNPs-Fe3O4@PDA exhibited highly catalytic activity for methylene blue reduction by NaBH4 with a rate constant of 1.44 × 10‑3/s, which was much higher than those by other AgNPs catalysts. The AgNPs-Fe3O4@PDA promised good recyclability for at least 8 cycles and acid resistant with good stability.

  11. Removal of silver nanoparticles by mussel-inspired Fe3O4@ polydopamine core-shell microspheres and its use as efficient catalyst for methylene blue reduction

    Science.gov (United States)

    Wu, Maoling; Li, Yinying; Yue, Rui; Zhang, Xiaodan; Huang, Yuming

    2017-01-01

    The removal of silver nanoparticles (AgNPs) from water is highly needed because of their increasing use and potential risk to the environment due to their toxic effects. Catalysis over AgNPs has received significant attention because of their highly catalytic performance. However, their use in practical applications is limited due to high cost and limited resources. Here, we present for the first time that the mussel-inspired Fe3O4@polydopamine (Fe3O4@PDA) nanocomposite can be used for efficient removal and recovery of AgNPs. Adsorption of AgNPs over Fe3O4@PDA was confirmed by TEM, FT-IR, XRD, TGA and magnetic property. The adsorption efficiency of AgNPs by Fe3O4@PDA was investigated as a function of pH, contact time, ionic strength and concentration of AgNPs. The kinetic data were well fitted to a pseudo-second order kinetic model. The isotherm data were well described by Langmuir model with a maximum adsorption capacity of 169.5 mg/g, which was higher than those by other adsorbents. Notably, the obtained AgNPs-Fe3O4@PDA exhibited highly catalytic activity for methylene blue reduction by NaBH4 with a rate constant of 1.44 × 10−3/s, which was much higher than those by other AgNPs catalysts. The AgNPs-Fe3O4@PDA promised good recyclability for at least 8 cycles and acid resistant with good stability. PMID:28202922

  12. 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.

  13. 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.

  14. 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.

  15. Magnetic recoverable Fe3O4-TiO2:Eu composite nanoparticles with enhanced photocatalytic activity

    Science.gov (United States)

    Stefan, M.; Leostean, C.; Pana, O.; Toloman, D.; Popa, A.; Perhaita, I.; Senilă, M.; Marincas, O.; Barbu-Tudoran, L.

    2016-12-01

    This work refers to the influence of Eu doping on the morphologic, structural and compositional properties of magnetic separable Fe3O4-TiO2 composite nanoparticles with photocatalytic activity. In this respect, Fe3O4-TiO2:Eu nanocomposites were prepared by seed mediated growth of TiO2:Eu through a sol-gel method onto preformed magnetite resulted from co-precipitation method. Different Eu concentration precursors were used for doping. The thermal behavior and the conversion of precursors into corresponding Fe3O4-TiO2:Eu composite nanoparticles were evidenced by FT-IR spectra and thermal analysis. The XRD, XPS and HRTEM investigations results indicate that nanocomposites contain besides Fe3O4-TiO2:Eu some amounts of iron titanate. Formation of FeTiO3 is suppressed by the increase of Eu doping level. Magnetic studies also indicated that nanocomposite exhibit superparamagnetic behavior at room temperature. The large surface area and mesoporous structure of magnetic nanocomposite were confirmed by the surface area (BET) and porosity measurements. It was demonstrated that the composite nanoparticles exhibit good photocatalytic activity toward the degradation of RhB solution and they can be used as efficient and conveniently recoverable photocatalyst.

  16. Synthesis and characterization of polyethylene glycol (PEG) coated Fe3O4 nanoparticles by chemical co-precipitation method for biomedical applications.

    Science.gov (United States)

    Anbarasu, M; Anandan, M; Chinnasamy, E; Gopinath, V; Balamurugan, K

    2015-01-25

    Polyethylene glycol (PEG) coated Fe3O4 nanoparticles were synthesized by chemical co-precipitation method. With polyethylene glycol (PEG) as a stabilizer and dispersant. The X-ray diffraction and selected area electron diffraction (SAED) results show that the cubic inverse spinel structure of pure phase polycrystalline Fe3O4 was obtained. The scanning electron microscopy (SEM) and field emission transmission electron microscopy (FE-TEM) results exhibited that the resulted Fe3O4 nanoparticles were roughly spherical in shape with narrow size distribution and homogenous shape. Fourier transform infrared spectroscopy (FT-IR) results suggested that PEG indicated with Fe3O4 via its carbonyl groups. Results of vibrating sample magnetometer (VSM) indicated that the prepared Fe3O4 nanoparticles exhibit superparamagnetic behavior and high saturation magnetization at room temperature. Such Fe3O4 nanoparticles with favorable size and tunable magnetic properties are promising biomedical applications.

  17. Influence of CuO nanoparticles and nanographene platelets on the photosonocatalytic performance of Fe3O4/TiO2 nanocomposites

    Science.gov (United States)

    Fauzian, M.; Harno, F. F.; Taufik, A.; Saleh, R.

    2016-11-01

    The effect of adding CuO nanoparticles and Nanographene Platelets (NGP) on Fe3O4/TiO2 nanocomposites to degrade dye waste were examined using photosonocatalytic process. Both nanocomposites Fe3O4/TiO2 with and without the addition of CuO were synthesized using sol-gel method, while the co-precipitation method was used to synthesize those two nanocomposites with NGP. All the samples were analyzed to identify their crystalline phase, magnetic property and thermal stability using X-Ray Diffraction (XRD), Vibrating Sample Magnetometer (VSM) and Thermogravimetric Analysis (TGA) measurements. The photosonocatalytic process of all samples were observed using the ultraviolet and ultrasonic radiation at the same time with the Methylene Blue (MB) as the model of dye waste. The results indicate that the presence of CuO nanoparticles and NGP on Fe3O4/TiO2 nanocomposites could increase its capacibility to degrade MB. Achievement of degradation up to 100% for a time of 2 hours is obtained by the presence of CuO nanoparticles and NGP simultaneously on Fe3O4/TiO2 nanocomposites.

  18. 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.

  19. 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.

  20. Self-assembly and graft polymerization route to Monodispersed Fe3O4@SiO2--polyaniline core-shell composite nanoparticles: physical properties.

    Science.gov (United States)

    Reddy, Kakarla Raghava; Lee, Kwang-Pill; Kim, Ju Young; Lee, Youngil

    2008-11-01

    This study describes the synthesis of monodispersed core-shell composites of silica-modified magnetic nanoparticles and conducting polyaniline by self-assembly and graft polymerization. Magnetic ferrite nanoparticles (Fe3O4) were prepared by coprecipitation of Fe+2 and Fe+3 ions in alkaline solution, and then silananized. The silanation of magnetic particles (Fe3O4@SiO2) was carried out using 3-bromopropyltrichlorosilane (BPTS) as the coupling agent. FT-IR spectra indicated the presence of Fe--O--Si chemical bonds in Fe3O4@SiO2. Core-shell type nanocomposites (Fe3O4@SiO2/PANI) were prepared by grafting polyaniline (PANI) on the surface of silanized magnetic particles through surface initiated in-situ chemical oxidative graft polymerization. The nanocomposites were characterized by high resolution transmission electron microscopy (HRTEM), X-ray diffraction (XRD), X-ray photoelectron spectra (XPS), Fourier transform infrared (FTIR) spectra, UV-visible spectroscopy, photoluminescence (PL) spectra, electrical conductivity and magnetic characteristics. HRTEM images of the nanocomposites revealed that the silica-modified magnetic particles made up the core while PANI made up the shell. The XPS spectrum revealed the presence of silica in the composites, and the XRD results showed that the composites were more crystalline than pure PANI. PL spectra show that composites exhibit photoluminescent property. Conductivity of the composites (6.2 to 9.4 x 10(-2) S/cm) was higher than that of pristine PANI (3.7 x 10(-3) S/cm). The nanocomposites exhibited superparamagnetism. Formation mechanism of the core-shell structured nanocomposites and the effect of modified magnetic nanoparticles on the electro-magnetic properties of the Fe3O4@SiO2/PANI nanocomposites are also investigated. This method provides a new strategy for the generation of multi-functional nanocomposites that composed of other conducting polymers and metal nanoparticles.

  1. 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.

  2. 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

    modified with PLGA:PEG2000, PLGA:PEG3000, and PLGA:PEG4000 copolymers was 69.5%, 73%, and 78%, respectively, and the release kinetics were controlled. The in vitro cytotoxicity test showed that the Fe3O4-PLGA:PEG4000 magnetic nanoparticles had no cytotoxicity and were biocompatible.Conclusion: There is potential for use of these nanoparticles for biomedical application. Future work includes in vivo investigation of the targeting capability and effectiveness of these nanoparticles in the treatment of lung cancer.Keywords: superparamagnetic iron oxide nanoparticles, triblock copolymer, doxorubicin encapsulation, water uptake, drug encapsulation efficiency

  3. Encapsulation of Fe3O4 Nanoparticles into N, S co-Doped Graphene Sheets with Greatly Enhanced Electrochemical Performance

    Science.gov (United States)

    Yang, Zunxian; Qian, Kun; Lv, Jun; Yan, Wenhuan; Liu, Jiahui; Ai, Jingwei; Zhang, Yuxiang; Guo, Tailiang; Zhou, Xiongtu; Xu, Sheng; Guo, Zaiping

    2016-01-01

    Particular N, S co-doped graphene/Fe3O4 hybrids have been successfully synthesized by the combination of a simple hydrothermal process and a subsequent carbonization heat treatment. The nanostructures exhibit a unique composite architecture, with uniformly dispersed Fe3O4 nanoparticles and N, S co-doped graphene encapsulant. The particular porous characteristics with many meso/micro holes/pores, the highly conductive N, S co-doped graphene, as well as the encapsulating N, S co-doped graphene with the high-level nitrogen and sulfur doping, lead to excellent electrochemical performance of the electrode. The N-S-G/Fe3O4 composite electrode exhibits a high initial reversible capacity of 1362.2 mAhg−1, a high reversible specific capacity of 1055.20 mAhg−1 after 100 cycles, and excellent cycling stability and rate capability, with specific capacity of 556.69 mAhg−1 when cycled at the current density of 1000 mAg−1, indicating that the N-S-G/Fe3O4 composite is a promising anode candidate for Li-ion batteries. PMID:27296103

  4. Encapsulation of Fe3O4 Nanoparticles into N, S co-Doped Graphene Sheets with Greatly Enhanced Electrochemical Performance

    Science.gov (United States)

    Yang, Zunxian; Qian, Kun; Lv, Jun; Yan, Wenhuan; Liu, Jiahui; Ai, Jingwei; Zhang, Yuxiang; Guo, Tailiang; Zhou, Xiongtu; Xu, Sheng; Guo, Zaiping

    2016-06-01

    Particular N, S co-doped graphene/Fe3O4 hybrids have been successfully synthesized by the combination of a simple hydrothermal process and a subsequent carbonization heat treatment. The nanostructures exhibit a unique composite architecture, with uniformly dispersed Fe3O4 nanoparticles and N, S co-doped graphene encapsulant. The particular porous characteristics with many meso/micro holes/pores, the highly conductive N, S co-doped graphene, as well as the encapsulating N, S co-doped graphene with the high-level nitrogen and sulfur doping, lead to excellent electrochemical performance of the electrode. The N-S-G/Fe3O4 composite electrode exhibits a high initial reversible capacity of 1362.2 mAhg‑1, a high reversible specific capacity of 1055.20 mAhg‑1 after 100 cycles, and excellent cycling stability and rate capability, with specific capacity of 556.69 mAhg‑1 when cycled at the current density of 1000 mAg‑1, indicating that the N-S-G/Fe3O4 composite is a promising anode candidate for Li-ion batteries.

  5. 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

    loaded with ADM or Tet can enhance the effective accumulation of the drugs in K562/A02. We propose that Fe3O4-MNPs loaded with ADM and Tet probably have synergetic effect on reversal in multidrug resistance.Keywords: magnetic nanoparticles, tetrandrine, adriamycin, multidrug resistance reversal, leukemia K562/A02

  6. Monodisperse magnetite (Fe3O4) nanoparticles modified with water soluble polymers for the diagnosis of breast cancer by MRI method

    Science.gov (United States)

    Rezayan, Ali Hossein; Mousavi, Majid; Kheirjou, Somayyeh; Amoabediny, Ghasem; Ardestani, Mehdi Shafiee; Mohammadnejad, Javad

    2016-12-01

    In this study, magnetic nanoparticles (MNPs) were synthesized via co-precipitation method. To enhance the biocompatibility and colloidal stability of the synthesized nanoparticles, they were modified with carboxyl functionalized PEG via dopamine (DPA) linker. Both modified and unmodified Fe3O4 nanoparticles exhibited super paramagnetic behavior (particle size below 20 nm). The saturation magnetization (Ms) of PEGdiacid-modified Fe3O4 was 45 emu/g, which was less than the unmodified Fe3O4 nanoparticles (70 emu/g). This difference indicated that PEGdiacid polymer was immobilized on the surface of Fe3O4 nanoparticles successfully. To evaluate the efficiency of the resulting nanoparticles as contrast agents for magnetic resonance imaging (MRI), different concentration of MNPs and different value of echo time TE were investigated. The results showed that by increasing the concentration of the nanoparticles, transverse relaxation time (T2) decreased, which subsequently resulted in MR signal enhancement. T2-weighted MR images of the different concentration of MNPs in different value of echo time TE indicated that MR signal intensity increased with increase in TE value up to 66 and then remained constant. The cytotoxicity effect of the modified and unmodified nanoparticles was evaluated in three different concentrations (12, 60 and 312 mg l-1) on MDA-MB-231 cancer cells for 24 and 48 h. In both tested time (24 and 48 h) for all three samples, the modified nanoparticles had long life time than unmodified nanoparticles. Cellular uptake of modified MNPs was 80% and reduced to 9% by the unmodified MNPs.

  7. 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%.

  8. 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.

  9. Immobilization of Thermostable Lipase QLM on Core-Shell Structured Polydopamine-Coated Fe3O4 Nanoparticles

    Directory of Open Access Journals (Sweden)

    Chenhui Wang

    2017-02-01

    Full Text Available Here, core-shell structured polydopamine-coated Fe3O4 nanoparticles were constructed to immobilize thermostable lipase QLM from Alcaligenes sp. Systematical characterization indicated that lipase QLM was successfully immobilized on the surface of nanoparticles with an enzyme loading of 21.4 ± 1.47 mg/g immobilized enzyme. Then, the immobilized enzyme was demonstrated to possess favorable catalytic activity and stability in the ester hydrolysis, using p-nitrophenyl caprylate as the substrate. Further, it was successfully employed in the kinetic resolution of (R, S-2-octanol, and satisfactory enantioselectivity and recyclability could be obtained with an enantiomeric ratio (E of 8–15 over 10 cycle reactions. Thus, core-shell structured polydopamine-coated Fe3O4 nanoparticles can be potentially used as a carrier for enzyme immobilization to improve their activity, stability, and reusability, which is beneficial for constructing efficient catalysts for industrial biocatalysis.

  10. Fabrication of Fe3O4 Nanoparticle-coalesced Hydroxylated Multi-walled Carbon Nanotubes for the Analysis of Strychnine in Human Serum.

    Science.gov (United States)

    Feng, Zufei; Xu, Yuehong; Wei, Shuguang; Zhang, Bao; Guan, Fanglin; Li, Shengbin

    2015-01-01

    A magnetic carbon nanomaterial for Fe3O4-modified hydroxylated multi-walled carbon nanotubes (Fe3O4-MWCNTs-OH) was prepared by the aggregating effect of Fe3O4 nanoparticles on MWCNTs-OH, and this material was combined with high-performance liquid chromatography (HPLC)/photodiode array detector (PAD) to determine strychnine in human serum samples. Some important parameters that could influence the extraction efficiency of strychnine were optimized, including the extraction time, amounts of Fe3O4-MWCNTs-OH, pH of sample solution, desorption solvent and desorption time. Under optimal conditions, the recoveries of spiked serum samples were between 98.3 and 102.7%, and the relative standard deviations (RSDs) ranged from 0.9 to 5.3%. The correlation coefficient was 0.9997. The LODs and LOQs of strychnine were 6.2 and 20.5 ng mL(-1), at signal-to-noise ratios of 3 and 10, respectively. These experimental results showed that the proposed method is feasible for the analysis of strychnine in serum samples.

  11. 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.

  12. 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.

  13. Shape-dependent microwave permeability of Fe3O4 nanoparticles: a combined experimental and theoretical study.

    Science.gov (United States)

    Yang, Yong; Yang, Yang; Xiao, Wen; Neo, Chye Poh; Ding, Jun

    2015-07-03

    Shape anisotropy is crucial for the microwave permeability of magnetic nanoparticles. In this work, we conduct a systematic study on the shape-dependent microwave permeability of magnetic nanoparticles. Three kinds of Fe3O4 nanoparticles with different geometric shapes (rod, disc, and octahedron) are fabricated by chemical methods and their permeability is investigated through both theoretical calculation and experiment. The results suggest that the rod could exhibit the highest resonance frequency (fr), while the lowest resonance frequency could be found in the octahedron. An opposite trend is observed in the initial permeability (μ0). In order to confirm the experimental permeability, we establish an improved LL-G model, which could take both the shape anisotropy and magnetic domain structure into account by introducing a local effective anisotropy field (Heff). The good agreement between the calculated and experimental permeability proves that the model can reproduce shape-dependent microwave permeability of magnetic nanoparticles. More importantly, no fitting process is involved in this model, enabling us to predict the permeability of magnetic nanostructures independent of experiment results.

  14. 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

  15. Use of hydroxypropyl-β-cyclodextrin/polyethylene glycol 400, modified Fe3O4 nanoparticles for congo red removal.

    Science.gov (United States)

    Yu, Lan; Xue, Weihua; Cui, Lei; Xing, Wen; Cao, Xinli; Li, Hongyu

    2014-03-01

    Fe3O4 nanoparticles were modified with Hydroxypropyl-β-cyclodextrin (HP-β-CD) and Polyethylene glycol 400 (PEG400) by a facile one-pot homogeneous precipitation method, and were used as a novel nano-adsorbent for the removal of congo red (CR) from aqueous solutions. The polymer-modified composites were characterized by FTIR, TEM, TGA, XRD and VSM, and showed excellent adsorption efficiency for CR. The value of the maximum adsorption capacity calculated according to the Langmuir isotherm model were 1.895g/g, which are much high and about 19 times that of Fe3O4 nanoparticles. Desorption study further indicates the good regeneration ability of the nanocomposites. The results suggest that the HP-β-CD/PEG400-modified Fe3O4 nanoparticles is a promising adsorbent for CR removal from aqueous solutions, and it is easily recycled owing to its large specific surface area and unique magnetic responsiveness. Crown Copyright © 2013. Published by Elsevier B.V. All rights reserved.

  16. Magnetic core/shell Fe3O4/Au nanoparticles for studies of quinolones binding to protein by fluorescence spectroscopy.

    Science.gov (United States)

    Jin, Rui; Song, Daqian; Xiong, Huixia; Ai, Lisha; Ma, Pinyi; Sun, Ying

    2016-03-01

    Magnetic core/shell Fe3O4/Au nanoparticles were used in the determination of drug binding to bovine serum albumin (BSA) using a fluorescence spectroscopic method. The binding constants and number of binding sites for protein with drugs were calculated using the Scatchard equation. Because of their superparamagnetic and biocompatible characteristics, magnetic core/shell Fe3O4/Au nanoparticles served as carrier proteins for fixing proteins. After binding of the protein to a drug, the magnetic core/shell Fe3O4/Au nanoparticles-protein-drug complex was separated from the free drug using an applied magnetic field. The free drug concentration was obtained directly by fluorescence spectrometry and the proteins did not influence the drug determination. So, the achieved number of binding sites should be reliable. The binding constant and site number for ciprofloxacin (CPFX) binding to BSA were 2.055 × 10(5) L/mol and 31.7, and the corresponding values for norfloxacin (NOR) binding to BSA were 1.383 × 10(5) L/mol and 38.8. Based on the achieved results, a suitable method was proposed for the determination of binding constants and the site number for molecular interactions. The method was especially suitable for studies on the interactions of serum albumin with the active ingredients of Chinese medicine.

  17. Study of 223Ra uptake mechanism by Fe3O4 nanoparticles: towards new prospective theranostic SPIONs

    Science.gov (United States)

    Mokhodoeva, Olga; Vlk, Martin; Málková, Eva; Kukleva, Ekaterina; Mičolová, Petra; Štamberg, Karel; Šlouf, Miroslav; Dzhenloda, Rustam; Kozempel, Ján

    2016-10-01

    The use of superparamagnetic iron oxide nanoparticles ( SPIONs) and radiolabelled nanoparticles ( NPs) has grown considerably over the recent years, and the SPIONs labelled with medicinal radionuclides offer new opportunities in multimodal diagnostics and in the drug-delivery systems for targeted alpha-particle therapy (TAT) driven by magnetic field gradient or by biologically active moieties bound on NPs shell. However, the mechanisms of NPs radiolabelling are not studied substantially and still remain unclear, even though the way of label attachment directly implies the stability of the label-nanoparticle construct. Since the 223Ra was the first clinically approved alpha-emitter, it is a promising nuclide for further development of its targeted carriers. We report here on the study of 223Ra uptake by the Fe3O4 SPIONs, together with an attempt to propose the 223Ra uptake mechanism by the Fe3O4 NPs in the presence of a phosphate buffer a typical formulation medium, under the pseudo-equilibrium conditions. Further, the in vitro stability tests of the prepared [223Ra]Fe3O4 NPs were performed to estimate the 223Ra label stability. The potential use of 223Ra-labelled SPIONs in theranostic applications is also discussed.

  18. Effects of Nanoscale Fe3O4 on Microbial Communities, Enzyme Activities and 2,4-D Degradation in Red Soil%纳米Fe3O4对红壤微生物数量、酶活性及2,4-D降解的影响

    Institute of Scientific and Technical Information of China (English)

    方国东; 司友斌

    2011-01-01

    [目的]从磁致效应的角度考察纳米四氧化三铁(Fe3O4)对红壤微生物数量和酶活性的影响,研究纳米Fe3O4处理对红壤中2,4-D的降解效果,为纳米磁处理技术用于污染土壤修复提供依据.[方法]采用不同剂量的纳米Fe3O4处理红壤,用稀释乎板法和化学比色法测定处理前后微生物数量和酶活性的变化;利用高效液相色谱(HPLC)测定土壤中2,4-D浓度的变化.[结果]纳米Fe3O4对细菌和放线菌有激活效应,但对真菌存在抑制作用,且当纳米Fe3O4投加量为80 g·kg-1时磁致效应最显著:同样,纳米Fe3O4对淀粉酶、脲酶、中性磷酸酶和过氧化氢酶也具有激活效应,但对不同酶活性的影响程度存在差异;经纳米Fe3O4处理后红壤中2,4-D的降解率明显高于未处理组,7 d内2,4-D的降解率可达84%.[结论]纳米Fe3O4处理后红壤中的微生物数量和酶活性显著增加,且红壤对2,4-D的降解能力明显增强.%[Objective] The effects of magnetic field on microbial communities and enzyme activities in red soil by nanoscale Fe3O4 were investigated, and the degradation of herbicide 2,4-D in red soil after nanoscale Fe3O4 treatment was also studied. The research will provide a basis for soil remediation by magnetic nanoparticles treatment. [Method] The red soil was treated by different dosages of nanoscale Fe3O4, then the microbial communities and enzyme activities were analyzed by dilution plate method and chemical assay, and the concentration of 2,4-D in soil was determined by high performance liquid chromatography (HPLC).[Result] The results indicated that the nanoscale Fe3O4 treatment had a positive effect on bacteria and actinomycetes, however, the fungi number was decreased by the same treatment. The effects of magnetic field on microbial communities increased with the dosage of nanoscale Fe3O4, and the microbial number reached the maximum at the dosage of 80 g·kg-1. Similarly, the nanoscale Fe3O4 could also improve

  19. 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.

  20. Mössbauer studies of stoichiometry of Fe3O4: characterization of nanoparticles for biomedical applications

    Science.gov (United States)

    Johnson, C. E.; Johnson, J. A.; Hah, H. Y.; Cole, M.; Gray, S.; Kolesnichenko, V.; Kucheryavy, P.; Goloverda, G.

    2016-12-01

    The iron oxide Fe3O4, the mineral magnetite sometimes called ferrosoferric oxide, is notoriousy non-stoichiometric even in bulk form so its formula may be written Fe3-δO4. In nanoparticle form, where it has applications in medicine and information technology, it is even more susceptible to oxidation. In this paper we report synthesis and studies of superparamagnetic Fe3O4 nanoparticles with controlled diameters of 5.3, 10.6 and 11.9 nm. In room temperature spectra, departures from stoichiometry δ of up to 0.02 were estimated from the relative amounts of Fe 3+/ Fe 2+ and from their isomer shifts. This cannot be used for very small particles of diameter 10.6 nm and less as they are superparamagnetic at room temperature and do not show hyperfine splitting owing to fast relaxation. Such particles have promise for use in enhancing MRI signals. The magnetic spectrum is restored by the application of a relatively small magnetic field (10 kG). As the temperature is lowered the relaxation slows down and 6-line magnetic hyperfine patterns appear below a blocking temperature TB. The values of TB obtained are lower than those of many other researchers reported in the literature, suggesting that our particles are less affected by magnetic interactions between them. At low temperatures all the spectra are similar and closely resemble that of bulk Fe3O4 confirming that departures from stoichiometry are small.

  1. Synthesis of New N-phenyl Fulleroisoxazoline in the Presence of Fe3O4@SiO2 Nanoparticles as an Efficient Magnetically Recoverable and Reusable Catalyst

    Directory of Open Access Journals (Sweden)

    J. Safaei-Ghomi

    2014-07-01

    Full Text Available In this research an effective and appropriate method has been developed for one-pot synthesis of new N-phenyl fulleroisoxazoline using Fe3O4@SiO2 nanoparticles as a green magnetically recyclable catalyst. The prepared catalytic samples were characterized by XRD, SEM, FT-IR and VSM. The products have been characterized by physical and spectroscopic data such as IR, 1H NMR, 13C NMR, and MS analyses.

  2. 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.

  3. 银铁纳米复合材料的脑胶质瘤放射增敏作用%Enhancing radiosensitivity of glioma cells with Ag/Fe3O4 nanoparticles

    Institute of Scientific and Technical Information of China (English)

    柴湘婷; 刘连科

    2011-01-01

    目的 研究银/四氧化三铁纳米复合材料(Ag/Fe3O4)对人源性脑胶质瘤U251细胞的放射敏感性的影响.方法 人源性脑胶质瘤U251细胞分为对照组、Ag/Fe3O4组、放疗组、Ag/Fe3O4复合放疗组.用集落形成实验检测Ag/Fe3O4对U251细胞放疗效果;流式细胞术检测银纳米颗粒(AgNPs)对细胞周期和凋亡率的影响.结果 Ag/Fe3O4能够引起U251细胞G2/M期阻滞,并使细胞放疗后凋亡率显著提高(P<0.05).结论 可利用Ag/Fe3O4纳米颗粒提高脑胶质瘤放射敏感性.%Objective To study the effect of Ag/Fe3O4 nanoparticles on the efficacy of radiosensitivity enhancement of U251 glioma cells. Methods U251 cells were divided into four groups of control, Ag/Fe3 O4, radiotherapy and Ag/Fe3 O4 combined with radiotherapy. The effect of Ag/Fe3O4 nanoparticles on radiosensitivity of glioma cells was detected by colony-forming assay. The cell cycles and apoptosis after irritation were tested by flow cytometry. Results Ag/Fe3 O4 nanoparticles could induce cell cycle in G2/M arrest and increased cells apoptosis rate after radiotherapy (P<0. 05). Conclusion The Ag/Fe3O4 nanostructures can significantly enhance radiosensitivity of glioma cells.

  4. Application of mixed colloidal magnetic fluid of single domain Fe3O4 and NiFe2O4 ferrite nanoparticles in audio speaker

    Directory of Open Access Journals (Sweden)

    S. D. Kemkar

    2017-01-01

    Full Text Available Ferrofluids are stable suspensions of colloidal ferrimagnetic particles in suitable non – magnetic carrier liquids. They have attracted a lot of attention from scientists and engineers due to their many interesting properties and applications in various branches of engineering. The present work reports the performance of colloidal fluid of single domain nanoparticles of NiFe2O4 and Fe3O4. The thermal properties and its dynamics on magnetization as well as its effect on thermal conductivity on the colloidal fluid are studied here. Advantages of the increased thermal conductivity and optimization of magnetization of mixed colloidal fluid is used to extract the heat from voice coil. Nanoparticles of 21 nm of Fe3O4 and 12 nm of NiFe2O4 are used for mixed colloidal fluid. The suspension of particles is achieved by coating the nanoparticles with mono-corboxylic group on both the types of particles. The higher size (21 nm of Fe3O4 and 12 nm of NiFe2O4 particles are taken for synthesizing colloidal fluid, to have magnetic property of mixed colloidal liquid at elevated temperature of voice coil of speaker (Higher sized particles gives better magnetization. Oil is used as a carrier. Mixed magnetic colloidal fluid is used as a medium for damping so that noise is reduced at higher temperature of voice coil.

  5. 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.

  6. Systematic evaluation of biocompatibility of magnetic Fe3O4 nanoparticles with six different mammalian cell lines

    Science.gov (United States)

    Liu, Yingxun; Chen, Zhongping; Wang, Jinke

    2011-01-01

    This article systematically evaluated the biocompatibility of multiple mammalian cell lines to 11-nm DMSA-coated Fe3O4 magnetic nanoparticles (MNPs). Cells including RAW264.7, THP-1, Hepa1-6, HepG2, HL-7702, and HeLa were incubated with six different concentrations (0, 20, 30, 40, 50, and 100 μg/mL) of MNPs for 48 h, and then the cell labeling, iron loading, cell viability, apoptosis, cycle, and oxidative stress were all quantitatively evaluated. The results revealed that all the cells were effectively labeled by the nanoparticles; however, the iron loading of RAW264.7 was significantly higher than that of other cells at any dose. The proliferations of all the cells were not significantly suppressed by MNPs at the studied dose except HepG2 that was exposed to 100 μg/mL MNPs. The investigation of oxidative stress demonstrated that the levels of total superoxide dismutase and xanthine oxidase had no significant changes in all the cells treated by all the doses of MNPs, while the levels of malonyldialdehyde activity of MNP-treated cells significantly increased. The nanoparticles did not produce any significant effect on cell cycles at any of the doses, but resulted in significant apoptosis of THP-1 and HepG2 cells at the highest concentration of 100 μg/mL. At a concentration of 30 μg/mL which was used in human studies with an intravascular nanoparticle imaging agent (Combidex), the nanoparticles efficiently labeled all the cells studied, but did not produce any significant influence on their viability, oxidative stress, and apoptosis and cycle. Therefore, the nanoparticles were concluded with better biocompatibility, which provided some useful information for its clinical applications.

  7. Green synthesis of magnetic Fe3O4 nanoparticles using Couroupita guianensis Aubl. fruit extract for their antibacterial and cytotoxicity activities.

    Science.gov (United States)

    G, Sathishkumar; V, Logeshwaran; S, Sarathbabu; Jha, Pradeep K; M, Jeyaraj; C, Rajkuberan; N, Senthilkumar; S, Sivaramakrishnan

    2017-05-29

    In the present study, a sustainable green chemistry approach was established to fabricate magnetic Fe3O4 nanoparticles (Fe3O4NPs) using the aqueous fruit extract of edible C. guianensis (CGFE). Synthesized NPs were further confirmed with different high-throughput characterization techniques such as UV-visible spectroscopy, FT-IR, XPS, DLS and zeta potential analysis. Additionally, XRD, AFM, HRTEM and SQUID VSM demonstrate the generation of crystalline CGFe3O4NPs with mean diameter of 17 ± 10 nm. Interestingly, CGFe3O4NPs exhibit a stupendous bactericidal action against different human pathogens which depicts its antimicrobial value. A significant dose-dependent cytotoxic effect of CGFe3O4NPs was noticed against treated human hepatocellular carcinoma cells (HepG2).

  8. EFFECT OF MAGNETIC FIELD ON THE CATALYTIC DECOMPOSITION OF H2O2 BY Fe3O4

    OpenAIRE

    Tapia-Huanambal, N.; Facultad de Química e Ingeniería Química Departamento de Fisicoquímica,Universidad Nacional mayor de San Marcos,Lima,Perú.; Kuo, Ch.; Departamento de Química de la Universidad Estatal de Arizona, Templo, AZ 85287-1604. EE.UU.; Lajavardi, M.; Departamento de Química de la Universidad Estatal de Arizona, Templo, AZ 85287-1604. EE.UU.; Lin, Sh.; Departamento de Química de la Universidad Estatal de Arizona, Templo, AZ 85287-1604. EE.UU.

    2014-01-01

    The decomposition of hydrogen peroxide H2O2, is a simple reaction to study the effect of the magnetic field in chemical reactivity. Hydrogen peroxide when dissolved in water is decomposed into oxygen and water slowly. In the absence of a catalyst, the reaction is extremely slow. We have studied the effect of the magnetic field in the synthesis of Fe3O4 and catalytic decomposition of H2O2 by Fe3O4 also propose a theoretical treatment of the magnetic field effect on chemical reactions. The resu...

  9. An electrochemical sensor for rizatriptan benzoate determination using Fe3O4 nanoparticle/multiwall carbon nanotube-modified glassy carbon electrode in real samples.

    Science.gov (United States)

    Madrakian, Tayyebeh; Maleki, Somayeh; Heidari, Mozhgan; Afkhami, Abbas

    2016-06-01

    In this paper a sensitive and selective electrochemical sensor for determination of rizatriptan benzoate (RZB) was proposed. A glassy carbon electrode was modified with nanocomposite of multiwalled carbon nanotubes (MWCNTs) and Fe3O4 nanoparticles (Fe3O4/MWCNTs/GCE). The results obtained clearly show that the combination of MWCNTs and Fe3O4 nanoparticles definitely improves the sensitivity of modified electrode to RZB determination. The morphology and electroanalytical performance of the fabricated sensor were characterized by scanning electron microscopy (SEM), transmission electron microscopy (TEM), X-ray diffraction (XRD), energy dispersive X-ray spectroscopy (EDS), square wave voltammetry (SWV) and cyclic voltammetry (CV). Also, the effect of experimental and instrumental parameters on the sensor response was evaluated. The square wave voltammetric response of the electrode to RZB was linear in the range 0.5-100.0 μmol L(-1) with a detection limit of 0.09 μmol L(-1) under the optimum conditions. The investigated method showed good stability, reproducibility and repeatability. The proposed sensor was successfully applied for real life samples of blood serum and RZB determination in pharmaceutical.

  10. 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

  11. Synthesis and properties of Fe3O4-activated carbon magnetic nanoparticles for removal of aniline from aqueous solution: equilibrium, kinetic and thermodynamic studies.

    Science.gov (United States)

    Kakavandi, Babak; Jonidi, Ahmad; Rezaei, Roshanak; Nasseri, Simin; Ameri, Ahmad; Esrafily, Ali

    2013-01-01

    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 r(2) > 0.98 and r(2) > 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.

  12. Antibacterial Nanocomposites Based on Fe3O4–Ag Hybrid Nanoparticles and Natural Rubber-Polyethylene Blends

    Directory of Open Access Journals (Sweden)

    Thanh Dung Ngo

    2016-01-01

    Full Text Available For the vulcanized natural rubber (NR, incorporation of silver nanoparticles (AgNPs into the NR matrix did not exhibit the bactericidal property against Escherichia coli (E. coli. However, incorporation of AgNPs into polyethylene (PE matrix showed good antibacterial activities to both Gram-negative and Gram-positive bacteria. In the present work, NR/PE (85/15 blends have been prepared by melt blending with presence of compatibilizer in an internal mixer. To possess antibacterial property, AgNPs (5–10 nm or Fe3O4–Ag hybrid nanoparticles (FAgNPs, 8 nm/16 nm were added into PE matrix before its blending with NR component. The tensile test indicated that the presence of compatibilizer in NR/PE blend significantly enhanced the tensile strength and elongation at break (up to 35% and 38% increases, resp.. The antibacterial activity test was performed by monitoring of the bacterial lag-log growth phases with the presence of nanocomposites in the E. coli cell culture reactor. The antibacterial test showed that the presence of FAgNPs in NR/PE blend had a better antibacterial activity than that obtained with the lone AgNPs. Two similar reasons were proposed: (i the faster Ag+ release rate from the Fe3O4–Ag hybrid nanoparticles due to the electron transfer from AgNP to Fe3O4 nanoparticle and (ii the fact that the ionization of AgNPs in hybrid nanostructure might be accelerated by Fe3+ ions.

  13. A noninvasive method to determine the fate of Fe(3O(4 nanoparticles following intravenous injection using scanning SQUID biosusceptometry.

    Directory of Open Access Journals (Sweden)

    Wei-Kung Tseng

    Full Text Available Magnetic nanoparticles (MNPs of Fe(3O(4 have been widely applied in many medical fields, but few studies have clearly shown the outcome of particles following intravenous injection. We performed a magnetic examination using scanning SQUID biosusceptometry (SSB. Based on the results of SSB analysis and those of established in vitro nonmagnetic bioassays, this study proposes a model of MNP metabolism consisting of an acute metabolic phase with an 8 h duration that is followed by a chronic metabolic phase that continues for 28 d following MNP injection. The major features included the delivery of the MNPs to the heart and other organs, the biodegradation of the MNPs in organs rich with macrophages, the excretion of iron metabolites in the urine, and the recovery of the iron load from the liver and the spleen. Increases in serum iron levels following MNP injection were accompanied by increases in the level of transferrin in the serum and the number of circulating red blood cells. Correlations between the in vivo and in vitro test results indicate the feasibility of using SSB examination for the measurement of MNP concentrations, implying future clinical applications of SSB for monitoring the hematological effects of MNP injection.

  14. A Discovery of Strong Metal-Support Bonding in Nanoengineered Au-Fe3O4 Dumbbell-like Nanoparticles by in Situ Transmission Electron Microscopy.

    Science.gov (United States)

    Han, Chang Wan; Choksi, Tej; Milligan, Cory; Majumdar, Paulami; Manto, Michael; Cui, Yanran; Sang, Xiahan; Unocic, Raymond R; Zemlyanov, Dmitry; Wang, Chao; Ribeiro, Fabio H; Greeley, Jeffrey; Ortalan, Volkan

    2017-08-09

    The strength of metal-support bonding in heterogeneous catalysts determines their thermal stability, therefore, a tremendous amount of effort has been expended to understand metal-support interactions. Herein, we report the discovery of an anomalous "strong metal-support bonding" between gold nanoparticles and "nano-engineered" Fe3O4 substrates by in situ microscopy. During in situ vacuum annealing of Au-Fe3O4 dumbbell-like nanoparticles, synthesized by the epitaxial growth of nano-Fe3O4 on Au nanoparticles, the gold nanoparticles transform into the gold thin films and wet the surface of nano-Fe3O4, as the surface reduction of nano-Fe3O4 proceeds. This phenomenon results from a unique coupling of the size-and shape-dependent high surface reducibility of nano-Fe3O4 and the extremely strong adhesion between Au and the reduced Fe3O4. This strong metal-support bonding reveals the significance of controlling the metal oxide support size and morphology for optimizing metal-support bonding and ultimately for the development of improved catalysts and functional nanostructures.

  15. 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.

  16. 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.

  17. Effect of Magnetic Fe_3O_4 Particles on Enzymatic Hydrolysis of Sunflower Seed Hull%磁性Fe_3O_4微粒对葵花籽壳酶水解的影响研究

    Institute of Scientific and Technical Information of China (English)

    陈玲; 袁兴中; 曾光明; 梁运姗; 鲁爱华; 赵佳佳

    2009-01-01

    The effect of magnetic Fe_3O_4 particles on cellulase in the enzymatic hydrolysis of sunflower seed hull was studied in different adding ways and additive amount. In the process of enzymatic hydrolysis of sunflower seed hull, the variations of cellulase activity, reducing sugar concentration and cellulose conversion were evaluated. After the reaction, the analysis of pH and surface tension of hydrolysate were also used to determine the mechanisms of cellulase by the magnetic effect. The results indicated that after adding magnetic Fe_3O_4, the cellulase activity, reducing sugar concentration and conversion of cellulose had an increased between the 0.5 g/L and 2.0 g/L cases after 48 h. When the additive amount of magnetic Fe_3O_4 was 2 g/L, the cellulase activity at 60 h was improved significantly by 25.9%. It was found that the concentration of reducing sugar was increased from 6.950 mg/mL to 8.775 mg/mL with magnetic Fe_3O_4 1.5 g/L. Simultaneously, compared with the blank, which the conversion of cellulose was 47.932%, the maximum cellulose conversion of samples with adding magnetic Fe_3O_4was 60.531%. Besides, the stability of cellulase activity adding in times was better than in one time. After the reaction, the final surface tension of hydrolysate with 1.5 g/L magnetic Fe_3O_4was the lowest in comparison with the blank. However, no significant differences were observed in the final pH of the hydrolysate.%将磁化后的Fe_3O_4微粒添加于葵花籽壳酶水解过程中,分析在不同的Fe_3O_4添加量和不同的添加方法下,葵花籽壳酶水解过程中纤维素酶酶活、纤维素转化率及还原糖浓度的变化特征,研究磁性Fe_3O_4微粒对纤维素酶水解葵花籽壳的影响.并通过考察酶水解反应前后水解液的表面张力值和pH值的变化,探讨和分析磁性Fe_3O_4微粒作用下纤维素酶的磁效应机制.结果表明,磁性Fe_3O_4添加量为0.5 g/L~2.0 g/L时,对纤维素酶酶活的提高,还原糖浓度的

  18. 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.

  19. 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.

  20. Gambogic acid-loaded magnetic Fe3O4 nanoparticles inhibit Panc-1 pancreatic cancer cell proliferation and migration by inactivating transcription factor ETS1

    Directory of Open Access Journals (Sweden)

    Wang C

    2012-02-01

    Full Text Available Cailian Wang1, Haijun Zhang1, Yan Chen1, Fangfang Shi1, Baoan Chen2,31Department of Oncology, 2Department of Hematology, Zhongda Hospital, 3Faculty of Oncology, Medical School, Southeast University, Nanjing, People’s Republic of ChinaBackground: E26 transformation-specific sequence-1 (ETS1 transcription factor plays important roles in both carcinogenesis and the progression of a wide range of malignancies. Aberrant ETS1 expression correlates with aggressive tumor behavior and a poorer prognosis in patients with various malignancies. The aim of the current study was to evaluate the efficacy of a drug delivery system utilizing gambogic acid-loaded magnetic Fe3O4 nanoparticles (GA-MNP- Fe3O4 on the suppression of ETS1-mediated cell proliferation and migration in Panc-1 pancreatic cancer cells.Methods: The effects caused by GA-MNP- Fe3O4 on the proliferation of Panc-1 pancreatic cancer cells were evaluated using a MTT (3-(4,5-dimethylthiazol-2-yl-2,5-diphenyltetrazolium bromide assay while inhibition of tumor cell migration was investigated in a scratch assay. The expressions of ETS1, cyclin D1, urokinase-type plasminogen activator (u-PA, and VEGF (vascular endothelial growth factor were examined by Western blot to elucidate the possible mechanisms involved.Results: In Panc-1 pancreatic cancer cells, we observed that application of GA-MNP- Fe3O4 was able to suppress cancer cell proliferation and prevent cells from migrating effectively. After treatment, Panc-1 pancreatic cancer cells showed significantly decreased expression of ETS1, as well as its downstream target genes for cyclin D1, u-PA, and VEGF.Conclusion: Our novel finding reaffirmed the significance of ETS1 in the treatment of pancreatic cancer, and application of GA-MNP- Fe3O4 nanoparticles targeting ETS1 should be considered as a promising contribution for better pancreatic cancer care.Keywords: ETS1 transcription factor, gambogic acid, pancreatic cancer, magnetic nanoparticles

  1. Preparation of polydopamine-coated graphene oxide/Fe3O4 imprinted nanoparticles for selective removal of fluoroquinolone antibiotics in water

    OpenAIRE

    Tan, Feng; Liu, Min; Ren, Suyu

    2017-01-01

    Antibiotics in water have recently caused increasing concerns for public health and ecological environments. In this work, we demonstrated polydopamine-coated graphene oxide/Fe3O4 (PDA@GO/Fe3O4) imprinted nanoparticles coupled with magnetic separation for fast and selective removal of fluoroquinolone antibiotics in water. The nanoparticles were prepared by the self-polymerization of dopamine using sarafloxacin as a template. The imprinted PDA film of 10~20?nm uniformly covered the surface of ...

  2. Monitoring Microalgae Population Growth by using Fe3O4 Nanoparticles-based Surface Plasmon Resonance (SPR) Biosensor

    Science.gov (United States)

    Nurrohman, D. T.; Oktivina, M.; Suharyadi, E.; Suyono, E. A.; Abraha, K.

    2017-05-01

    The population growth of microalgae has been successfully monitored by using the surface plasmon resonance (SPR)-based biosensor activated by using PEG-4000 functionalized Fe3O4 magnetic nanoparticles. The SPR-based biosensor in this work used Kretchmann configuration and Ha-Ne laser beam (λ = 633nm). The population of microalgae were estimated by using calibration curve. The shift of SPR angle happens due to the change of dielectric medium from prism/Au/air system to prism/Au/Fe3O4+PEG+microalgae/cover glass system. The change of dielectric medium occurs due to deposition of Fe3O4+PEG+microalgae samples that were monitored for seven days. The population of microalgae on the first day was estimated of 1188146 cell/ml and SPR angle had shifted from 42.80 to 69.00. The SPR angle shifted as much as 26.20. The population of microalga grew significantly on the third day as much as 1649106 cell/ml and the SPR angle had shifted 43.80 to 71.10. The SPR angle shifted as much as 27.30. On fourth to seventh day, the population of microalgae decreased. The population of microalgae on the seventh day was estimated of 1206961 cell/ml and the SPR angle had shifted from 44.00 to 68.80. The SPR angle shifted as much as 24.8 degrees. The shift of SPR angle was influenced by the population of microalgae so that the SPR-based biosensor has the potential for use in monitoring the microalgae population.

  3. 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.

  4. Novel yolk-shell-structured Fe3O4@γ-AlOOH nanocomposite modified with Pd nanoparticles as a recyclable catalyst with excellent catalytic activity

    Science.gov (United States)

    Cui, Xueliang; Zheng, Yunfeng; Tian, Meng; Dong, Zhengping

    2017-09-01

    A novel yolk-shell-structured material (Fe3O4@γ-AlOOH-YSMs) with hierarchical γ-AlOOH flakes as the mesoporous shell and Fe3O4 nanoparticles (NPs) in the hollow core was prepared by using Fe3O4@SiO2 NPs as the seeds as well as NaAlO2 and urea as the precursor. The prepared Fe3O4@γ-AlOOH-YSMs were used as a catalyst support for fabricating a Pd/Fe3O4@γ-AlOOH-YSMs nanocatalyst with no obvious aggregation of the Pd NPs. The Pd/Fe3O4@γ-AlOOH-YSMs nanocatalyst was utilized for the catalytic reduction of the widely used and highly toxic 4-nitrophenol, rhodamine B, methylene blue, and methyl orange; and showed excellent catalytic activity as compared with other noble-metal-based catalysts. Furthermore, the Pd/Fe3O4@γ-AlOOH-YSMs nanocatalyst also can be easily separated from the reaction mixture and reused for at least ten times without any obvious decrease in the catalytic activity, indicating its reusability and stability.

  5. Adsorption process of fluoride from drinking water with magnetic core-shell Ce-Ti@Fe3O4 and Ce-Ti oxide nanoparticles.

    Science.gov (United States)

    Abo Markeb, Ahmad; Alonso, Amanda; Sánchez, Antoni; Font, Xavier

    2017-11-15

    Synthesized magnetic core-shell Ce-Ti@Fe3O4 nanoparticles were tested, as an adsorbent, for fluoride removal and the adsorption studies were optimized. Adsorption capacity was compared with the synthesized Ce-Ti oxide nanoparticles. The adsorption equilibrium for the Ce-Ti@Fe3O4 adsorbent was found to occur in Ce-Ti oxides and Ce-Ti@Fe3O4 nanoparticles, respectively. The physical sorption mechanism was estimated using the Dubinin-Radushkevich model. An anionic exchange process between the OH(-) group on the surface of the Ce-Ti@Fe3O4 nanomaterial and the F(-) was involved in the adsorption. Moreover, thermodynamic parameters proved the spontaneous process for the adsorption of fluoride on Ce-Ti@Fe3O4 nanoparticles. The reusability of the material through magnetic recovery was demonstrated for five cycles of adsorption-desorption. Although the nanoparticles suffer slight structure modifications after their reusability, they keep their adsorption capacity. Likewise, the efficiency of the Ce-Ti@Fe3O4 was demonstrated when applied to real water to obtain a residual concentration of F(-) below the maximum contaminated level, 1.5mg/L (WHO, 2006). Copyright © 2017 Elsevier B.V. All rights reserved.

  6. A novel green synthesis of Fe3O4-Ag core shell recyclable nanoparticles using Vitis vinifera stem extract and its enhanced antibacterial performance

    Science.gov (United States)

    Venkateswarlu, Sada; Natesh Kumar, B.; Prathima, B.; Anitha, K.; Jyothi, N. V. V.

    2015-01-01

    We described a novel and eco-friendly method for preparing Fe3O4-Ag core shell nanoparticles (CSNPs) with high magnetism and potent antibacterial activity. The Fe3O4-Ag CSNPs were obtained using waste material of Vitis vinifera (grape) stem extract as the green solvent, reducing and capping agent. The result recorded from X-ray powder diffraction (XRD), UV-vis spectrum, energy dispersive spectroscopy (EDS), Fourier transform infrared spectroscopy (FT-IR) supports the biosynthesis and characterization of Fe3O4-Ag CSNPs. From transmission electron microscopy (TEM) the size of the Fe3O4-Ag nanoparticles was measured below 50 nm; high-resolution TEM (HRTEM) indicates the core shell structure; and selected area electron diffraction (SAED) has revealed polycrystalline nature. Vibrating sample magnetometer (VSM) shows the ferromagnetic nature of Fe3O4-Ag CSNPs at room temperature with saturation magnetization of 15.74 emu/g. Further, these biogenic nanoparticles were highly hazardous to microorganisms. The antibacterial activity of biogenic Fe3O4-Ag CSNPs showed potent inhibitory activity against both Gram-positive and Gram-negative pathogens. These nanoparticles may also be reusable because of its excellent ferromagnetic property.

  7. Synthesis and characterization of magnetically recyclable Ag nanoparticles immobilized on Fe3O4@C nanospheres with catalytic activity

    Science.gov (United States)

    Li, Wei-hong; Yue, Xiu-ping; Guo, Chang-sheng; Lv, Jia-pei; Liu, Si-si; Zhang, Yuan; Xu, Jian

    2015-04-01

    A novel approach for the synthesis of Ag-loaded Fe3O4@C nanospheres (Ag-Fe3O4@C) was successfully developed. The catalysts possessed a carbon-coated magnetic core and grew active silver nanoparticles on the outer shell using hydrazine monohydrate as the AgNO3 reductant in ethanol. The morphology, inner structure, and magnetic properties of the as-prepared composites were studied with transmission electron microscopy (TEM), X-ray powder diffraction (XRD), fourier translation infrared spectroscopy (FT-IR), and vibrating sample magnetometer (VSM) techniques. Catalytic activity was investigated by degrading rhodamine B (RhB) in the designed experiment. The obtained products were monodispersed and bifunctional with high magnetization, as well as exhibited excellent catalytic activity toward organic dye with 98% of RhB conversion within 20 min in the presence of NaBH4. The product also exhibited convenient magnetic separability and maintained high catalytic activity after six cycle runs.

  8. 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).

  9. 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

  10. 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.

  11. 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.

  12. Aptamer-functionalized Fe3 O4 magnetic nanoparticles as a solid-phase extraction adsorbent for the selective extraction of berberine from Cortex phellodendri.

    Science.gov (United States)

    Jiang, Ling-Feng; Chen, Bo-Cheng; Chen, Ben; Li, Xue-Jian; Liao, Hai-Lin; Zhang, Wen-Yan; Wu, Lin

    2017-07-01

    The extraction adsorbent was fabricated by immobilizing the highly specific recognition and binding of aptamer onto the surface of Fe3 O4 magnetic nanoparticles, which not only acted as recognition elements to recognize and capture the target molecule berberine from the extract of Cortex phellodendri, but also could favor the rapid separation and purification of the bound berberine by using an external magnet. The developed solid-phase extraction method in this work was useful for the selective extraction and determination of berberine in Cortex phellodendri extracts. Various conditions such as the amount of aptamer-functionalized Fe3 O4 magnetic nanoparticles, extraction time, temperature, pH value, Mg(2+) concentration, elution time and solvent were optimized for the solid-phase extraction of berberine. Under optimal conditions, the purity of berberine extracted from Cortex phellodendri was as high as 98.7% compared with that of 4.85% in the extract, indicating that aptamer-functionalized Fe3 O4 magnetic nanoparticles-based solid-phase extraction method was very effective for berberine enrichment and separation from a complex herb extract. The applicability and reliability of the developed solid-phase extraction method were demonstrated by separating berberine from nine different concentrations of one Cortex phellodendri extract. The relative recoveries of the spiked solutions of all the samples were between 95.4 and 111.3%, with relative standard deviations ranging between 0.57 and 1.85%. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  13. 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

  14. Enhanced Analytical Performance of Paper Microfluidic Devices by Using Fe3O4 Nanoparticles, MWCNT, and Graphene Oxide.

    Science.gov (United States)

    Figueredo, Federico; Garcia, Paulo T; Cortón, Eduardo; Coltro, Wendell K T

    2016-01-13

    Spheres, tubes, and planar-shaped nanomaterials as Fe3O4 nanoparticles (MNPs), multiwalled carbon nanotubes (MWCNT), and graphene oxide (GO) were used for the first time to treat microfluidic paper-based analytical devices (μPADs) and create a biocompatible layer with high catalytic surface. Once glucose measurements are critical for diabetes or glycosuria detection and monitoring, the analytical performance of the proposed devices was studied by using bienzymatic colorimetric detection of this carbohydrate. The limit of detection values achieved for glucose with μPADs treated with MNPs, MWCNT, and GO were 43, 62, and 18 μM, respectively. The paper surface modification solves problems associated with the lack of homogeneity on color measurements that compromise the sensitivity and detectability levels in clinical diagnosis.

  15. Passively Q-switched erbium-doped fiber laser using Fe3O4-nanoparticle saturable absorber

    Science.gov (United States)

    Bai, Xuekun; Mou, Chengbo; Xu, Luxi; Wang, Shaofei; Pu, Shengli; Zeng, Xianglong

    2016-04-01

    We experimentally demonstrate passively Q-switched erbium-doped fiber laser (EDFL) operation using a saturable absorber (SA) based on Fe3O4 nanoparticles (FONPs). As a type of transition metal oxide, the FONPs have a large nonlinear optical response and fast response time. The FONP-based SA possesses a modulation depth of 8.2% and nonsaturable absorption of 56.6%. Stable passively Q-switched EDFL pulses with an output pulse energy of 23.76 nJ, a repetition rate of 33.3 kHz, and a pulse width of 3.2 µs were achieved when the input pump power was 110 mW. The laser features a low threshold pump power of ∼15 mW.

  16. Comparing three methods of simultaneous synthesis and stabilization of Fe3O4 nanoparticles: Changing physicochemical properties of products to improve kinetic and thermodynamic of dye adsorption

    Science.gov (United States)

    Rakhshaee, Roohan; Noorani, Yasaman

    2017-01-01

    Fe3O4 nanoparticles (FNPs) were synthesized by conventional heating (CH), co-precipitation (CP) and microwave heating (MH) methods in presence of pectin crosslinked by β-isopropylglutaric acid (-CP) to stabilize nanoparticles. The role of the cross-linked pectin and kinds of synthesis methods was appeared to increase the effective total surface of FNPs both simultaneously as the synergistic effects and separately. The effective role of the microwave irradiation to decrease FNPs mean size was seen, so that its size in FMH was smaller 21.5% and 38.2% than that of FCP and FCH, and in FMH-CP was smaller 27.2% and 58.9% than that of FCP-CP and FCH-CP, respectively. The various experiments were done on the structures, functional groups, and connection quantities of -CP to FNPs synthesized by CH, CP and MH methods. The different physical properties of the obtained composites containing magnetization, zeta potential and thermal analyses were determined. To study the adsorption of methylene blue (MB) from the aqueous and alkali solution, the role Fe-O- groups of FNPs was evaluated more effective than the role of -COO- and -O- of -CP in the stabilized nanoparticles. Fe3O4 NPs stabilized by -CP using microwave heating showed the highest capacity of MB adsorption due to having the most suitable thermodynamic and kinetic parameters.

  17. Multifunctional Fe3O4 nanoparticles for highly sensitive detection and removal of Al(iii) in aqueous solution

    Science.gov (United States)

    Zhi, Lihua; Liu, Jian; Wang, Yuan; Zhang, Wei; Wang, Baodui; Xu, Zhuguo; Yang, Zhengyin; Huo, Xing; Li, Guangming

    2013-01-01

    Fe3O4 nanoparticles (NPs) decorated with rhodamine 6G Schiff base, which exhibit high selectivity and sensitivity toward Al3+ over other common metal ions in aqueous media under a physiological pH window via a 1 : 1 binding mode, have been synthesized and characterized. The resulting conjugate 1c renders the rhodamine 6G Schiff base unit more water soluble, and the detection limit reaches 0.3 ppb in water. Moreover, 1c can detect Al3+ in a wide pH span (5.0-11.0) and enrich/remove excess Al3+ in water via an external magnetic field, which indicates that it has more potential and further practical applications for biology and toxicology. Furthermore, 1c provides good fluorescent imaging of Al3+ in living cells.Fe3O4 nanoparticles (NPs) decorated with rhodamine 6G Schiff base, which exhibit high selectivity and sensitivity toward Al3+ over other common metal ions in aqueous media under a physiological pH window via a 1 : 1 binding mode, have been synthesized and characterized. The resulting conjugate 1c renders the rhodamine 6G Schiff base unit more water soluble, and the detection limit reaches 0.3 ppb in water. Moreover, 1c can detect Al3+ in a wide pH span (5.0-11.0) and enrich/remove excess Al3+ in water via an external magnetic field, which indicates that it has more potential and further practical applications for biology and toxicology. Furthermore, 1c provides good fluorescent imaging of Al3+ in living cells. Electronic supplementary information (ESI) available. See DOI: 10.1039/c2nr33200k

  18. Influence of nanographene platelets (NGP) incorporation on Fe3O4 nanoparticles as materials additives for enhancement thermal properties stearic acid

    Science.gov (United States)

    Nuryadin, M. K.; Andiarto, R.; Taufik, A.; Saleh, R.

    2016-11-01

    In this work, Fe3O4 nanoparticles, and Fe3O4/NGP composite were used as material additive for enhancement thermal properties of stearic acid (SA). The both material additive were synthesized using sol-gel method. Phase change material (PCM) composites SA-Fe3O4 and Sa-Fe3O4/NGP mixtures were made through the dispersion technique with three different weight % ratio of material additives into stearic acid: 1 wt.%, 3 wt.%, and 5 wt.%. X-Ray Diffractometer (XRD) and Fourier Transform Infrared (FTIR) spectroscopy were used to investigate the structural properties. Magnetic properties also measured by vibrating sample magnetometer (VSM) to see influence of NGP in PCM composites. Differential Scanning Calorimetry (DSC) and Thermogravimetric Analysis (TGA) were used in order to analyse the thermal properties of the samples. The results show an enhancement of the latent heat, thermal stability as well as specific heat by the presence of material additives in SA. Compare to SA- Fe3O4, SA-Fe3O4/NGP show better improvement in enhancement of thermal performance of SA. The improvement by about 41.2% in specific heat and 21.2% in latent heat.

  19. A novel magneto-fluorescent microsphere: Preparation and characterization of polystyrene-supported Fe3O4 and CdS nanoparticles

    Science.gov (United States)

    Kaboudin, Babak; Ghaderian, Abolfazl

    2013-10-01

    Novel sulfonated polystyrene microsphere containing Fe3O4 and CdS nanoparticles have been prepared and characterized. A thorough structural characterization has been carried out by means of transmission electron microscopy (TEM), scanning electron microscopy (SEM) images, VSM data, EDS, and photoluminescence spectroscopy. The presence of the magnetic nanoparticles (Fe3O4) and CdS nanoparticles on the polystyrene microspheres has been demonstrated. Cadmium diethyl dithiophosphate (CDDP) has been used as a 3 in 1 precursor (cadmium, sulfur, and ligand source) for the synthesis of high-quality CdS nanoparticles on polystyrene microsphere containing Fe3O4 nanoparticles. This novel composite exhibits both fluorescence and magnetism properties that may be used in a novel bioprobe.

  20. Near-ultraviolet lateral photovoltaic effect in Fe3O4/3C-SiC Schottky junctions.

    Science.gov (United States)

    Song, Bingqian; Wang, Xianjie; Li, Bo; Zhang, Lingli; Lv, Zhe; Zhang, Yu; Wang, Yang; Tang, Jinke; Xu, Ping; Li, Bingsheng; Yang, Yanqiang; Sui, Yu; Song, Bo

    2016-10-17

    In this paper, we report a sensitive lateral photovoltaic effect (LPE) in Fe3O4/3C-SiC Schottky junctions with a fast relaxation time at near-ultraviolet wavelengths. The rectifying behavior suggests that the large build-in electric field was formed in the Schottky junctions. This device has excellent position sensitivity as high as 67.8 mV mm-1 illuminated by a 405 nm laser. The optical relaxation time of the LPE is about 30 μs. The fast relaxation and high positional sensitivity of the LPE make the Fe3O4/3C-SiC junction a promising candidate for a wide range of ultraviolet/near-ultraviolet optoelectronic applications.

  1. 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.

  2. 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

  3. 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.

  4. A comparative study on the morphology of P3HT:PCBM solar cells with the addition of Fe3O4 nanoparticles by spin and rod coating methods

    Science.gov (United States)

    Zhang, Wenluan; Nguyen, Ngoc A.; Murray, Roy; Xin, Jiyuan; Mackay, Michael E.

    2017-09-01

    Our previous study presented up to 20% power conversion efficiency (PCE) enhancement of poly(3-hexylthiophene):phenyl-C61-butyric acid methyl ester (P3HT:PCBM) solar cells under the Fe3O4 nanoparticles (NPs) self-assembly (SA) effect by spin coating. Fe3O4 NPs (about 11 nm hydrodynamic diameter) form a thin layer at the top interface of the light absorbing active layer, which results in the generation of PCBM rich region improving the charge transport (Zhang et al. Sol Energ Mat Sol C 160:126-133, 2017). In order to investigate the feasibility of this Fe3O4 NPs SA effect under large-scale production condition, a smooth rod was implemented to mimic roll-to-roll coating technique and yield active layers having about the same thickness as the spin-coated ones. Small angle neutron scattering and grazing incidence X-ray diffraction were employed finding out similar morphologies of the active layers by these two coating techniques. However, rod-coated solar cell's PCE decreases with the addition of Fe3O4 NPs compared with the one without them. This is because PCBM rich region is not created at the top interface of the active layer due to the absence of Fe3O4 NPs, which is attributed to the weak convective flow and low diffusion rate. Moreover, in the rod-coated solar cells, the presence of Fe3O4 NPs causes decrease in P3HT crystallinity, thus the charge transport and the device performance. Our study confirms the role of spin coating in the Fe3O4 NPs SA effect and enables researchers to explore this finding in other polymer nanocomposite systems.

  5. Immobilization of horseradish peroxidase on Fe3O4 magnetic nanoparticles

    Directory of Open Access Journals (Sweden)

    Saleh A. Mohamed

    2017-05-01

    Conclusions: Physical immobilization of HRP on iron magnetic nanoparticles improved the stability toward the denaturation induced by pH, heat, metal ions, urea, detergent, and water-miscible organic solvent.

  6. Effect of Fe(3)O(4) on the sedimentation and structure-property relationship of starch under different pHs.

    Science.gov (United States)

    Palanikumar, S; Siva, P; Meenarathi, B; Kannammal, L; Anbarasan, R

    2014-06-01

    The nanosized ferrite (Fe3O4) was synthesized and characterized by analytical techniques such as Fourier transform infrared (FTIR) spectroscopy, UV-visible spectroscopy, fluorescence spectroscopy and transmission electron microscopy (TEM). The structure-property relationship of starch was studied under three different pHs namely 3.8, 7.1 and 12.5. The starch treated under acidic condition was degraded. In a similar manner, the structure-property relationship of starch in the presence of ferrite nanoparticles at three different pHs, as mentioned above was studied. The starch/ferrite nanocomposite prepared under acidic condition showed a degraded structure. Further, the polymer/nanocomposite systems were characterized by analytical techniques such as FTIR, differential scanning calorimetry (DSC), thermogravimetric analysis (TGA), vibrating sample measurement (VSM), TEM and scanning electron microscopy (SEM). Finally, the settling velocity of starch under three different pHs both in the presence and absence of Fe3O4 was carried out to ensure the role of pH and effect of Fe3O4 on the settling velocity of starch.

  7. 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.

  8. Preparation and characterization of cross-linked β-cyclodextrin polymer/Fe3O4 composite nanoparticles with core-shell structures

    Institute of Scientific and Technical Information of China (English)

    Rui Xue Li; Shu Mei Liu; Jian Qing Zhao; Hideyuki Otsuka; Atsushi Takahara

    2011-01-01

    Cross-linked β-cyclodextrin polymer/Fe3O4 composite nanoparticles with core-shell structures were prepared via cross linking reaction on the surface of carboxymethyl β-cyclodextrin (CM-β-CD) modified Fe3O4 nanoparticles in β-cyclodextrin alkaline solution by using epichlorohydrin as crosslinking agent. The morphology, structure and magnetic properties of the prepared composite nanoparticles were investigated by transmission electron microscopy (TEM), Fourier transform infrared (FTIR) spectrometry, X-ray diffraction (XRD) measurement, thermogravimetric analysis (TGA) and Vibrating sample magnetometry (VSM), respectively.

  9. Fabrication of Fe3O4/SiO2 core/shell nanoparticles attached to graphene oxide and its use as an adsorbent.

    Science.gov (United States)

    Yao, Yunjin; Miao, Shiding; Yu, Shaoming; Ma, Li Ping; Sun, Hongqi; Wang, Shaobin

    2012-08-01

    Amino-functionalized Fe(3)O(4)/SiO(2) core/shell nanoparticles were synthesized by reacting Fe(3)O(4) nanoparticles with tetraethyl orthosilicate and (3-aminopropyl) triethoxysilane to introduce amino groups on the surface. The amino groups on the Fe(3)O(4)/SiO(2) were reacted with the carboxylic groups of graphene oxide (GO) with the aid of 1-ethyl-3-(3-dimethylaminopropyl)carbodiimide and N-hydroxysuccinnimide to form Fe(3)O(4)/SiO(2)GO nanoparticles. The structural, surface, and magnetic characteristics of the material were investigated by scanning and transmission electron microscopy, energy-dispersive X-ray spectrometry, powder X-ray diffraction, Fourier transform infrared spectroscopy, and thermogravimetric analysis. Adsorption equilibrium and kinetics of methylene blue on the Fe(3)O(4)/SiO(2)GO were studied in a batch system. The maximum adsorption capacities were found to be 97.0, 102.6, and 111.1 mg g(-1) at 25, 45, and 60°C, respectively. A second-order kinetic equation could best describe the sorption kinetics. Thermodynamic parameters indicated that the adsorption of methylene blue onto the material was thermodynamically feasible and could occur spontaneously.

  10. 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.

  11. Synthesis and characterization of Fe3O4-PEG-LAC-chitosan-PEI nanoparticle as a survivin siRNA delivery system.

    Science.gov (United States)

    Arami, S; Rashidi, M R; Mahdavi, M; Fathi, M; Entezami, A A

    2017-03-01

    The limited effectiveness of the conventional methods for cancer treatment makes the researchers to find novel safe and effective therapeutic strategies. One of these strategies is to use small interfering RNAs (siRNAs). A major challenge here is the siRNA delivery into the cells. The purpose of this study was to design and prepare a biocompatible, biodegradable, and safe nanosized particle for siRNA delivery into human breast cancer MCF-7 and leukemia K562 cells. Chemically synthesized magnetic nanoparticles containing polyethyleneglycol-lactate polymer (PEG-LAC), chitosan, and polyethyleneimine (PEI) were successfully prepared and used as a gene delivery vehicle. The nanoparticles were characterized by Fourier transform infrared spectroscopy and zeta potential. The Fe3O4-PEG-LAC-chitosan-PEI nanoparticle showed efficient and stable survivin siRNA loading in gel retardation assay. The cytotoxicity of the prepared nanoparticle was studied using 3-(4,5-dimethyl-2-thiazolyl)-2,5-diphenyl-2H-tetrazolium bromide assay and was compared with that of mitoxantrone (MTX) in combination with the prepared siRNA delivery system to evaluate the possible synergic effect of MTX and survivin siRNA. The nanoparticles with and without noncomplementary siRNA showed low toxicity against both cell lines; however, a twofold decrease was observed in cell survival percent after MTX addition to MCF-7 cells treated with either nanoparticle itself or complexed with noncomplementary siRNA. While survivin siRNA nanoplex caused threefold decrease in the cell survival percent, its combination with MTX did not result in a significant increase in the cytotoxic effect. Therefore, Fe3O4-PEG-LAC-chitosan-PEI nanoparticle should be considered as a potential carrier for enhanced survivin siRNA delivery into MCF-7 and K562 cells.

  12. Enhanced Magnetism of Fe3O4 Nanoparticles with Ga Doping

    Energy Technology Data Exchange (ETDEWEB)

    Pool, V. L.; Klem, M. T.; Chorney, C. L.; Arenholz, E.; Idzerda, Y.U.

    2010-10-22

    Magnetic (Ga{sub x}Fe{sub 1-x}){sub 3}O{sub 4} nanoparticles with 5%-33% gallium doping (x = 0.05-0.33) were measured using x-ray absorption spectroscopy and x-ray magnetic circular dichroism to determine that the Ga dopant is substituting for Fe{sub 3+} as Ga{sub 3+} in the tetrahedral A-site of the spinel structure, resulting in an overall increase in the total moment of the material. Frequency-dependent alternating-current magnetic susceptibility measurements showed these particles to be weakly interacting with a reduction of the cubic anisotropy energy term with Ga concentration. The element-specific dichroism spectra show that the average Fe moment is observed to increase with Ga concentration, a result consistent with the replacement of A-site Fe by Ga.

  13. 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.

  14. Synthesis of Fe3O4@nickel-silicate core-shell nanoparticles for His-tagged enzyme immobilizing agents

    Science.gov (United States)

    Shin, Moo-Kwang; Kang, Byunghoon; Yoon, Nam-Kyung; Kim, Myeong-Hoon; Ki, Jisun; Han, Seungmin; Ahn, Jung-Oh; Haam, Seungjoo

    2016-12-01

    Immobilizing enzymes on artificially fabricated carriers for their efficient use and easy removal from reactants has attracted enormous interest for decades. Specifically, binding platforms using inorganic nanoparticles have been widely explored because of the benefits of their large surface area, easy surface modification, and high stability in various pH and temperatures. Herein, we fabricated Fe3O4 encapsulated ‘sea-urchin’ shaped nickel-silicate nanoparticles with a facile synthetic route. The enzymes were then rapidly and easily immobilized with poly-histidine tags (His-tags) and nickel ion affinity. Porous nickel silicate covered nanoparticles achieved a high immobilization capacity (85 μg mg-1) of His-tagged tobacco etch virus (TEV) protease. To investigate immobilized TEV protease enzymatic activity, we analyzed the cleaved quantity of maltose binding protein-exendin-fused immunoglobulin fusion protein, which connected with the TEV protease-specific cleavage peptide sequence. Moreover, TEV protease immobilized nanocomplexes conveniently removed and recollected from the reactant by applying an external magnetic field, maintained their enzymatic activity after reuse. Therefore, our newly developed nanoplatform for His-tagged enzyme immobilization provides advantageous features for biotechnological industries including recombinant protein processing.

  15. 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.

  16. A simplified method for synthesis of Fe3O4@PAA nanoparticles and its application for the removal of basic dyes

    Science.gov (United States)

    Xu, Yin-Yin; Zhou, Min; Geng, Hui-Juan; Hao, Jun-Jie; Ou, Qian-Qian; Qi, Sheng-Da; Chen, Hong-Li; Chen, Xing-Guo

    2012-02-01

    A simplified method for synthesis of polyacrylic acid-bound iron oxide magnetic nanoparticles (Fe3O4@PAA NPs) was reported. The as-prepared nanoparticles were characterized by TEM, FT-IR, VSM and XRD. Characterization results indicated that PAA was successfully introduced onto the surface of Fe3O4 and did not cause any changes in magnetic property. The Fe3O4@PAA NPs were used to adsorb rhodamine 6G (R6G) as a model basic dye pollutant from aqueous solution. Kinetics data and adsorption isotherms were better fitted by pseudo-second-order kinetic model and Langmuir isotherm, respectively. The adsorption equilibrium could be reached at about 20 min, showing that the as-prepared adsorbent exhibited extremely rapid adsorption rate. The aqueous solution of the Yellow River was chosen as the test sample, and the results showed that the magnetic adsorbent was efficient for the removal of the basic dye in the real sample.

  17. Defluoridation technology for drinking water and tea by green synthesized Fe3O4/Al2O3 nanoparticles coated polyurethane foams for rural communities.

    Science.gov (United States)

    Kumari, Sonu; Khan, Suphiya

    2017-08-14

    Fluoride (F) contaminated ground water poses a serious public health concern to rural population with unaffordable purification technologies. Therefore, development of a cost-effective, portable, environment and user-friendly defluoridation technique is imperative. In the present study, we report on the development of a green and cost-effective method that utilizes Fe3O4 and Al2O3 nanoparticles (NPs) that were synthesized using jojoba defatted meal. These NPs were impregnated on to polyurethane foam (PUF) and made into tea infusion bags. The Al2O3 NPs-PUF displayed a higher water defluoridation capacity of 43.47 mg g(-1) of F as compared to 34.48 mg g(-1) of F with Fe3O4 NPs-PUF. The synthesized Al2O3-PUF infusion bags removed the F that was under the permissible limit of 1.5 mg L(-1). The sorption experiments were conducted to verify the effect of different parameters such as pH, contact time, size of PUF and initial F concentration. The different properties of adsorbent were characterized using a combination of FESEM, EDX, XRD and FTIR techniques, respectively. The calculated total cost per NPs-PUF pouch developed is as low as US $0.05, which makes the technology most suitable for rural communities. This paper will be beneficial for researchers working toward further improvement in water purification technologies.

  18. Synthesis of Al2O3-Coated Fe3O4 Nanoparticles for Thermomagnetic Processing

    Science.gov (United States)

    2015-12-01

    Jaramillo RA, Babu SS, Ludtka GM, Kisner RA, Wilgen JB, Mackiewicz- Ludtka G, Nicholson DM, Kelly SM, Murugananth M, Bhadeshia HKDH. Effect of 30T magnetic...field on transformations in a novel bainitic steel. Scripta Materialia. 2005;52:461–466. 8. Ludtka GM, Jaramillo RA, Kisner RA, Nicholson DM, Wilgen

  19. 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.

  20. Facile synthesis of Fe3O4 nanoparticles by reduction phase transformation from gamma-Fe2O3 nanoparticles in organic solvent.

    Science.gov (United States)

    Hai, Hoang Tri; Kura, Hiroaki; Takahashi, Migaku; Ogawa, Tomoyuki

    2010-01-01

    A phase transformation induced by the reduction of as-synthesized gamma-maghemite (gamma-Fe(2)O(3)) nanoparticles was performed in solution by exploiting the reservoir of reduction gas (CO) generated from the incomplete combustion reaction of organic substances in the reactor. Results from X-ray diffraction, color indicator, and magnetic analysis using a SQUID strongly support this phase transformation. Based on this route, monodisperse magnetite (Fe(3)O(4)) nanoparticles were simply produced in the range from 260 to 300 degrees C. Almost all aspects of the original gamma-Fe(2)O(3) nanoparticles, such as shape, size, and monodispersity, were maintained in the produced Fe(3)O(4) nanoparticles.

  1. Multifunctional Fe3O4/TaO(x) core/shell nanoparticles for simultaneous magnetic resonance imaging and X-ray computed tomography.

    Science.gov (United States)

    Lee, Nohyun; Cho, Hye Rim; Oh, Myoung Hwan; Lee, Soo Hong; Kim, Kangmin; Kim, Byung Hyo; Shin, Kwangsoo; Ahn, Tae-Young; Choi, Jin Woo; Kim, Young-Woon; Choi, Seung Hong; Hyeon, Taeghwan

    2012-06-27

    Multimodal imaging is highly desirable for accurate diagnosis because it can provide complementary information from each imaging modality. In this study, a sol-gel reaction of tantalum(V) ethoxide in a microemulsion containing Fe(3)O(4) nanoparticles (NPs) was used to synthesize multifunctional Fe(3)O(4)/TaO(x) core/shell NPs, which were biocompatible and exhibited a prolonged circulation time. When the NPs were intravenously injected, the tumor-associated vessel was observed using computed tomography (CT), and magnetic resonance imaging (MRI) revealed the high and low vascular regions of the tumor.

  2. 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...

  3. Thermochemotherapy effect of nanosized As2O3/Fe3O4 complex on experimental mouse tumors and its influence on the expression of CD44v6, VEGF-C and MMP-9

    Directory of Open Access Journals (Sweden)

    Zhang Dongsheng

    2009-10-01

    Full Text Available Abstract Background Both thermotherapy and arsenic have been shown to be active against a broad spectrum of cancers. To reduce the limitations of conventional thermotherapy, improve therapeutic anticancer activity, reduce the toxicity of arsenic on normal tissue, and increase tissue-specific delivery, we prepared a nanosized As2O3/Fe3O4 complex (Fe3O4 magnetic nanoparticles encapsulated in As2O3. We assessed the thermodynamic characteristics of this complex and validated the hyperthermia effect, when combined with magnetic fluid hyperthermia (MFH, on xenograft HeLa cells (human cervical cancer cell line in nude mice. We also measured the effect on the expression of CD44v6, VEGF-C, and MMP-9 which were related to cancer and/or metastasis. Results The nanosized As2O3/Fe3O4 particles were approximately spherical, had good dispersibility as evidenced by TEM, and an average diameter of about 50 nm. With different concentrations of the nanosized As2O3/Fe3O4 complex, the correspondingsuspension of magnetic particles could attain a steady temperature ranging from 42°C to 65°C when placed in AMF for 40 min. Thermochemotherapy with the nanosized As2O3/Fe3O4 complex showed a significant inhibitory effect on the mass (88.21% and volume (91.57% of xenograft cervical tumors (p 2O3/Fe3O4 complex significantly inhibited the expression of CD44v6, VEGF-C, and MMP-9 mRNA (p Conclusion As2O3/Fe3O4 complex combined with MFH had is a promising technique for the minimally invasive elimination of solid tumors and may be have anticancerometastasic effect by inhibiting the expression of CD44v6, VEGF-C, and MMP-9.

  4. 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.

  5. h-BN Nanosheets as 2D Substrates to Load 0D Fe3O4 Nanoparticles: A Hybrid Anode Material for Lithium-Ion Batteries.

    Science.gov (United States)

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

    2016-03-18

    h-BN, as an isoelectronic analogue of graphene, has improved thermal mechanical properties. Moreover, the liquid-phase production of h-BN is greener since harmful oxidants/reductants are unnecessary. Here we report a novel hybrid architecture by employing h-BN nanosheets as 2D substrates to load 0D Fe3O4 nanoparticles, followed by phenol/formol carbonization to form a carbon coating. The resulting carbon-encapsulated h-BN@Fe3O4 hybrid architecture exhibits synergistic interactions: 1) The h-BN nanosheets act as flexible 2D substrates to accommodate the volume change of the Fe3O4 nanoparticles; 2) The Fe3O4 nanoparticles serve as active materials to contribute to a high specific capacity; and 3) The carbon coating not only protects the hybrid architecture from deformation but also keeps the whole electrode highly conductive. The synergistic interactions translate into significantly enhanced electrochemical performances, laying a basis for the development of superior hybrid anode materials.

  6. 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.

  7. Synergistic effect of a combination of nanoparticulate Fe3O4 and gambogic acid on phosphatidylinositol 3-kinase/Akt/Bad pathway of LOVO cells

    Directory of Open Access Journals (Sweden)

    Hu S

    2012-07-01

    Full Text Available Lianghua Fang,1,3 Baoan Chen,2 Shenlin Liu,3 Ruiping Wang,3 Shouyou Hu,3 Guohua Xia,2 Yongli Tian,3 Xiaohui Cai21No 1 Clinical Medical College of Nanjing University of Chinese Medicine, 2Department of Hematology, Zhongda Hospital, Medical School, Southeast University, 3Department of Oncology, Jiangsu Province Hospital of Traditional Chinese Medicine, Nanjing, People's Republic of ChinaBackground: The present study evaluated whether magnetic nanoparticles containing Fe3O4 could enhance the activity of gambogic acid in human colon cancer cells, and explored the potential mechanisms involved.Methods: Cytotoxicity was evaluated by MTT assay. The percentage of cells undergoing apoptosis was analyzed by flow cytometry, and cell morphology was observed under both an optical microscope and a fluorescence microscope. Reverse transcriptase polymerase chain reaction and Western blot assay were performed to determine the transcription of genes and expression of proteins, respectively.Results: Gambogic acid could inhibit proliferation of LOVO cells in a dose-dependent and time-dependent manner and induce apoptosis, which was dramatically enhanced by magnetic nanoparticles containing Fe3O4. The typical morphological features of apoptosis in LOVO cells were observed after treatment comprising gambogic acid with and without magnetic nanoparticles containing Fe3O4. Transcription of cytochrome c, caspase 9, and caspase 3 genes was higher in the group treated with magnetic nanoparticles containing Fe3O4 and gambogic acid than in the groups that received gambogic acid or magnetic nanoparticles containing Fe3O4, but transcription of phosphatidylinositol 3-kinase, Akt, and Bad genes decreased. Notably, expression of cytochrome c, caspase 9, and caspase 3 proteins in the group treated with gambogic acid and magnetic nanoparticles containing Fe3O4 was higher than in the groups receiving magnetic nanoparticles containing Fe3O4 or gambogic acid, while expression of p-PI3

  8. Synthesis and Characterization of magnetic Fe3O4/Au Magnetic Composite Nanoparticles%Fe3O4/Au磁性纳米复合微粒的制备及表征

    Institute of Scientific and Technical Information of China (English)

    彭菊村; 吴波英; 陈杰

    2008-01-01

    实验中应用水相合成法制备Fe3O4/Au纳米复合微粒,通过对复合微粒生成过程的光谱检测,对生成物的磁响应性检测和采用HGMF磁分离,表明绝大多数颗粒既具有磁性,又具有纳米Au的特征.将获得的不同粒径的磁性颗粒分别与纯Fe3O4,Au纳米微粒进行选区电子衍射对比分析.结果表明,粒径越小的复合颗粒的衍射花样越接近纯Fe3O4,随粒径的增大,与纯Fe3O4的差异增大;当粒径增大到(15.8±2.8) nm,衍射花样与纯Au纳米颗粒的完全吻合,间接证实了Fe3O4/Au纳米复合微粒的核壳结构.

  9. 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

    nano-Fe3O4 to Pb2* reached 172.4 mg·g-1, the sorption maxima of Fe3O4/HA to Cd2+, Cu2+ increased by 75.8% and 231.5% as compared with that of Fe3O4 nanoparticles. The adsorption of Fe3O4 and Fe3O4/MPTES to metal ions followed the order Pb2+>Cd2+>Cu2+,but Fe3O4/HA followed the order Pb2+>Cu2+>Cd2+; the coating of humic acid with Fe3O4 nanoparticles could obviously improve its adsorption capacity for Cd2+ and Cu2+ in solution, but marginal effect was observed for Pb2+.

  10. Metallic Nanoparticle (TiO2 and Fe3O4) Application Modifies Rhizosphere Phosphorus Availability and Uptake by Lactuca sativa.

    Science.gov (United States)

    Zahra, Zahra; Arshad, Muhammad; Rafique, Rafia; Mahmood, Arshad; Habib, Amir; Qazi, Ishtiaq A; Khan, Saud A

    2015-08-12

    Application of engineered nanoparticles (NPs) with respect to nutrient uptake in plants is not yet well understood. The impacts of TiO2 and Fe3O4 NPs on the availability of naturally soil-bound inorganic phosphorus (Pi) to plants were studied along with relevant parameters. For this purpose, Lactuca sativa (lettuce) was cultivated on the soil amended with TiO2 and Fe3O4 (0, 50, 100, 150, 200, and 250 mg kg(-1)) over a period of 90 days. Different techniques, such as scanning electron microscopy (SEM), energy-dispersive X-ray spectroscopy (EDX), Raman, and Fourier transform infrared spectroscopy (FTIR) were used to monitor translocation and understand the possible mechanisms for phosphorus (P) uptake. The trends for P accumulation were different for roots (TiO2 > Fe3O4 > control) and shoots (Fe3O4 > TiO2 > control). Cystine and methionine were detected in the rhizosphere in Raman spectra. Affinities of NPs to adsorb phosphate ions, modifications in P speciation, and NP stress in the rhizosphere had possibly contributed to enhanced root exudation and acidification. All of these changes led to improved P availability and uptake by the plants. These promising results can help to develop an innovative strategy for using NPs for improved nutrient management to ensure food security.

  11. Preparation of Fe3O4/MnOOH core-shell nanoparticles by a high-frequency impinging stream reactor☆

    Institute of Scientific and Technical Information of China (English)

    Dongguang Wang; Baikang Zhu; Hengcong Tao

    2015-01-01

    Well-defined Fe3O4/MnOOH nanoparticles with 61.1 emu·g−1 in magnetization intensity and 90.53 m2·g−1 in surface area have been synthesized by a new-style of high-frequency impinging stream (HFIS) reactor. In this reactor, two streams first collided together to form nano Fe3O4 suspension, which subsequently flew through an S-shaped maln channel to generate high-frequency reversing high-gravity fields. At the same time, 24 thin liquid sheets impinged into the maln channel at the frequencies higher than 100 Hz to create nano Fe3O4/MnOOH colloids. The obtalned powders were characterized by transmission electron microscopy/energy dispersive spectrometer (TEM/EDS), X-ray diffraction (XRD), Brunner–Emmet–Teller (BET) and vibrating sample magnetometer (VSM). Experimental results indicated that low coating ratio prolonged the induction period of heterogeneous nucleation. The high-frequency impingements of 24 thin liquid sheets greatly accelerated the macro-mixing and the initial dispersion. The high-frequency reversing high-gravity fields promoted the meso-and micro-mixing. As a result, nano Fe3O4 cores were fleetly and uniformly covered by MnOOH precursor. As a continuously operated and static high-gravity reactor, the high-frequency impinging stream (HFIS) reactor is being developed to the large-scaled and low-cost production of various nanocomposites.

  12. 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

  13. 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.

  14. Optimization of α-Fe2O3@Fe3O4 incorporated N-TiO2 as super effective photocatalysts under visible light irradiation

    Science.gov (United States)

    Mohamed, Mohamed Mokhtar; Bayoumy, W. A.; Goher, M. E.; Abdo, M. H.; Mansour El-Ashkar, T. Y.

    2017-08-01

    Well dispersed α-Fe2O3@Fe3O4 nanoparticles (7 nm) supported on mesoporous nitrogen doped titanium dioxide (N-TiO2) are synthesized by deposition self-assembly route and their performances as photocatalysts toward methylene blue (MB) degradation are evaluated. The results illustrate that the spherical yolk-shell structure of α-Fe2O3@Fe3O4@N-TiO2 at the loading of 1%; of excellent SBET (187 m2 g-1) and pore volume (0.50 cm3 g-1), achieved high photocatalytic performance for the MB degradation (20 ppm, λ > 420 nm, lamp power = 160 W) under visible light illumination (k = 0.059 min-1). The influence of the interface formation between α-Fe2O3@Fe3O4 and n-TiO2 affects severely the charges separation efficiency and enhances the electron transfer to keep on the existence of Fe3+/Fe2+ moieties; those take significant role in the reaction mechanism. The existence of the latter junction is affirmed via XRD, TEM-SAED, Raman and FTIR techniques whereas, the photogenerated charges, their separation together with their transport and recombination rates are depicted via photoluminescence, electrical conductivity, incident photon to current efficiency (IPCE), cyclic voltammetry (CV) and impedance (EIS) measurements. The catalyst loading, zero point charge, pH variation, total organic carbon (TOC%) and the effect of lamps power are thoroughly investigated. The 1%α-Fe2O3@Fe3O4@N-TiO2 photocatalyst also indicated high activity as a Fenton-like reagent accomplishing the MB degradation (100% removal) in 35 min with a rate of 0.07 min-1 at H2O2 concentration of 0.4 mM. The obtained results demonstrate that the heterojunction nanoscaled materials possess superior visible-light driven photocatalytic activity with appreciable recyclability and promising utilization as a supercapcitor (426 F g-1 at scan rate of 5 mV s-1) device.

  15. Interface exchange coupling induced fourfold symmetry planar Hall effect in Fe3O4/NiO bilayers

    Science.gov (United States)

    Li, P.; Cui, W. Y.; Bai, H. L.

    2015-10-01

    An unexpected fourfold symmetry planar Hall effect was observed in Fe3O4/NiO bilayers. As the thickness of the antiferromagnetic layer exceeds 37 nm, the planar Hall effect of the bilayer further shifts to twofold symmetry, which is ascribed to the dying interfacial coupled effect with increasing antiferromagnetic NiO layer thickness. According to the fitting based on the Stoner-Wohlfarth model, it was notable that an extra cubic anisotropic field in the bilayer structure was obviously amplified by attenuating the thickness of the antiferromagnetic layer. First principle calculations reveal that the amplified cubic anisotropic field was ascribed to the synergistic effect from interfacial bonding structure and charge transfer.

  16. Facile Preparation, Characterization, and Highly Effective Microwave Absorption Performance of CNTs/Fe3O4/PANI Nanocomposites

    Directory of Open Access Journals (Sweden)

    Deqing Zhang

    2013-01-01

    Full Text Available A facile method has been developed to synthesize light-weight CNTs/Fe3O4/PANI nanocomposites. The formation route was proposed as the coprecipitation of Fe2+ and Fe3+ and an additional process of in situ polymerization of aniline monomer. The structure and morphology of CNTs/Fe3O4/PANI were characterized by transmission electron microscopy (TEM, X-ray photoelectron spectroscopy (XPS, and Fourier transform infrared (FTIR spectroscopy. The TEM investigation shows that the CNTs/Fe3O4/PANI nanocomposites exhibit less intertwined structure and that many more Fe3O4 particles are attached homogeneously on the surface of CNTs, indicating that PANI can indeed help CNTs to disperse in isolated form. The wave-absorbing properties were investigated in a frequency of 2–18 GHz. The results show that the CNTs/Fe3O4/PANI nanocomposites exhibit a super absorbing behavior and possess a maximum reflection loss of −48 dB at 12.9 GHz, and the bandwidth below −20 dB is more than 5 GHz. More importantly, the absorption peak frequency ranges of the CNTs/Fe3O4/PANI composites can be tuned easily by changing the wax weight ratio and thickness of CNTs/Fe3O4/PANI paraffin wax matrix.

  17. 磁性纳米Fe3 O4促进的固相合成2,2’-二羟基-1,1’-联萘%Magnetic Fe3 O4 nanoparticles promoted solid-state synthesis of 2,2 ’-dihydroxy-1,1 ’-dinaphthalene

    Institute of Scientific and Technical Information of China (English)

    刘建平; 冯翠兰; 桂建舟; 刘澜涛

    2014-01-01

    研究了磁性纳米Fe3 O4促进的2-萘酚氧化偶联合成2,2’-二羟基-1,1’-联萘( BINOL)的反应,反应以空气中的O2为氧化剂,无溶剂的固相条件下进行。结果表明,在优化条件下:反应温度130℃,反应时间3.5 h,n(2-萘酚):n(Fe3O4)=1.7:1,BINOL的收率达到99.0%,且磁性纳米Fe3O4连续循环使用5次,BINOL的收率无明显降低。%Magnetic Fe3 O4 nanoparticles promoted solid-state synthesis of BINOL was studied,with 2-naphthol as substrate and oxygen in air as oxidant. Result showed that the optimized conditions were as follows:130 ℃,3. 5 h and n(2-naphthol):n( Fe3 O4 )=1. 7:1,the yield of BINOL up to 99. 0%. The separated magnetic Fe3 O4 nanoparticles can be recycled for 5 runs in the synthesis of BINOL reaction and the yield of BINOL without significantly decrease.

  18. Preparation of Fe(3)O(4)@C@CNC multifunctional magnetic core/shell nanoparticles and their application in a signal-type flow-injection photoluminescence immunosensor.

    Science.gov (United States)

    Chu, Chengchao; Li, Meng; Li, Long; Ge, Shenguang; Ge, Lei; Yu, Jinghua; Yan, Mei; Song, Xianrang

    2013-11-01

    We describe here the preparation of carbon-coated Fe3O4 magnetic nanoparticles that were further fabricated into multifunctional core/shell nanoparticles (Fe3O4@C@CNCs) through a layer-by-layer self-assembly process of carbon nanocrystals (CNCs). The nanoparticles were applied in a photoluminescence (PL) immunosensor to detect the carcinoembryonic antigen (CEA), and CEA primary antibody was immobilized onto the surface of the nanoparticles. In addition, CEA secondary antibody and glucose oxidase were covalently bonded to silica nanoparticles. After stepwise immunoreactions, the immunoreagent was injected into the PL cell using a flow-injection PL system. When glucose was injected, hydrogen peroxide was obtained because of glucose oxidase catalysis and quenched the PL of the Fe3O4@C@CNC nanoparticles. The here proposed PL immunosensor allowed us to determine CEA concentrations in the 0.005–50 ng·mL-1 concentration range, with a detection limit of 1.8 pg·mL-1.

  19. Thermoelectric performance of spin Seebeck effect in Fe3O4/Pt-based thin film heterostructures

    Directory of Open Access Journals (Sweden)

    R. Ramos

    2016-10-01

    Full Text Available We report a systematic study on the thermoelectric performance of spin Seebeck devices based on Fe3O4/Pt junction systems. We explore two types of device geometries: a spin Hall thermopile and spin Seebeck multilayer structures. The spin Hall thermopile increases the sensitivity of the spin Seebeck effect, while the increase in the sample internal resistance has a detrimental effect on the output power. We found that the spin Seebeck multilayers can overcome this limitation since the multilayers exhibit the enhancement of the thermoelectric voltage and the reduction of the internal resistance simultaneously, therefore resulting in significant power enhancement. This result demonstrates that the multilayer structures are useful for improving the thermoelectric performance of the spin Seebeck effect.

  20. Thermoelectric performance of spin Seebeck effect in Fe3O4/Pt-based thin film heterostructures

    Science.gov (United States)

    Ramos, R.; Anadón, A.; Lucas, I.; Uchida, K.; Algarabel, P. A.; Morellón, L.; Aguirre, M. H.; Saitoh, E.; Ibarra, M. R.

    2016-10-01

    We report a systematic study on the thermoelectric performance of spin Seebeck devices based on Fe3O4/Pt junction systems. We explore two types of device geometries: a spin Hall thermopile and spin Seebeck multilayer structures. The spin Hall thermopile increases the sensitivity of the spin Seebeck effect, while the increase in the sample internal resistance has a detrimental effect on the output power. We found that the spin Seebeck multilayers can overcome this limitation since the multilayers exhibit the enhancement of the thermoelectric voltage and the reduction of the internal resistance simultaneously, therefore resulting in significant power enhancement. This result demonstrates that the multilayer structures are useful for improving the thermoelectric performance of the spin Seebeck effect.

  1. 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.

  2. 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.

  3. 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.

  4. Preparation of polydopamine-coated graphene oxide/Fe3O4 imprinted nanoparticles for selective removal of fluoroquinolone antibiotics in water.

    Science.gov (United States)

    Tan, Feng; Liu, Min; Ren, Suyu

    2017-07-18

    Antibiotics in water have recently caused increasing concerns for public health and ecological environments. In this work, we demonstrated polydopamine-coated graphene oxide/Fe3O4 (PDA@GO/Fe3O4) imprinted nanoparticles coupled with magnetic separation for fast and selective removal of fluoroquinolone antibiotics in water. The nanoparticles were prepared by the self-polymerization of dopamine using sarafloxacin as a template. The imprinted PDA film of 10~20 nm uniformly covered the surface of GO/Fe3O4 providing selective binding sites. The nanoparticles showed rapid binding and a large capacity (70.9 mg/g). The adsorption data fitted well the Langmuir and pseudo-second order kinetic equations. The nanoparticles could be easily separated by a magnet following the adsorption and then regenerated by simple washing for repetitive adsorptions. The nanoparticles were successfully used for the removal of fluoroquinolone antibiotics in seawater, with removal efficiencies of more than 95%. The proposed strategy has potentials for efficient removal of antibiotics in environmental water.

  5. Effect of magnetic anisotropy and particle size distribution on temperature dependent magnetic hyperthermia in Fe3O4 ferrofluids

    Science.gov (United States)

    Palihawadana Arachchige, Maheshika; Nemala, Humeshkar; Naik, Vaman; Naik, Ratna

    Magnetic hyperthermia (MHT) has a great potential as a non-invasive cancer therapy technique. Specific absorption rate (SAR) which measures the efficiency of heat generation, mainly depends on magnetic properties of nanoparticles such as saturation magnetization (Ms) and magnetic anisotropy (K) which depend on the size and shape. Therefore, MHT applications of magnetic nanoparticles often require a controllable synthesis to achieve desirable magnetic properties. We have synthesized Fe3O4 nanoparticles using two different methods, co-precipitation (CP) and hydrothermal (HT) techniques to produce similar XRD crystallite size of 12 nm, and subsequently coated with dextran to prepare ferrofluids for MHT. However, TEM measurements show average particle sizes of 13.8 +/-3.6 nm and 14.6 +/-3.6 nm for HT and CP samples, implying the existence of an amorphous surface layer for both. The MHT data show the two samples have very different SAR values of 110 W/g (CP) and 40W/g (HT) at room temperature, although they have similar Ms of 70 +/-4 emu/g regardless of their different TEM sizes. We fitted the temperature dependent SAR using linear response theory to explain the observed results. CP sample shows a larger magnetic core with a narrow size distribution and a higher K value compared to that of HT sample.

  6. 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.

  7. Synthesis and application of magnetic magnetite nanoparticles%磁性纳米Fe3O4的制备与应用进展

    Institute of Scientific and Technical Information of China (English)

    陈大勇; 陈平

    2009-01-01

    总结了磁性纳米Fe3O4粒子的微乳液法、热分解铁有机物法、共沉淀法、凝胶-溶胶法、生物模板合成法等.并讨论了磁性纳米Fe3O4粒子在生物分离、靶向药物、肿瘤磁热疗以及免疫检测等领域的应用.%This paper summarized the preparation methods of magnetic magnetite nanoparticles, such as microemul-sion method, coprecipation method, gel-sol method, high-temperature decomposition method, etc. At the same time, the application of magnetic magnetite nanoparticles such as isolation and determination of biological compounds , targeting drug , cancer therapy was described in detail.

  8. 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.

  9. Synthesis of Fe3O4@SiO2-Ag magnetic nanocomposite based on small-sized and highly dispersed silver nanoparticles for catalytic reduction of 4-nitrophenol.

    Science.gov (United States)

    Chi, Yue; Yuan, Qing; Li, Yanjuan; Tu, Jinchun; Zhao, Liang; Li, Nan; Li, Xiaotian

    2012-10-01

    In this work, we report a facile method to generate core-shell structured Fe(3)O(4)@SiO(2)-Ag magnetic nanocomposite by an in situ wet chemistry route with the aid of polyvinylpyrrolidone as both reductant and stabilizer. This method can effectively prevent Ag nanoparticles from aggregating on the silica surface, thus resulting highly dispersed and small-sized Ag nanoparticles. The as-prepared nanocomposite is composed of a central magnetite core with a strong response to external fields, an interlayer of SiO(2), and numerous highly dispersed Ag nanoparticles with a narrow size distribution. Furthermore, the Fe(3)O(4)@SiO(2)-Ag nanocomposite showed high performance in the catalytic reduction of 4-nitrophenol and could be easily recycled by applying an external magnetic field while maintaining the catalytic activity without significant decrease even after running 15 times.

  10. 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.

  11. Fe3o4 nanoparticles: A highly efficient and easily reusable catalyst for the one-pot synthesis of xanthene derivatives under solvent-free conditions

    Directory of Open Access Journals (Sweden)

    Ghasemzadeh Ali Mohammad

    2013-01-01

    Full Text Available Magnetically separable Fe3O4 nanoparticles supply environmentally friendly procedure for the synthesis of 14-aryl-14H-dibenzo[a,j]xanthene and 1,8-dioxo-octahydro-xanthene derivatives. These compounds were obtained in high yields and short reaction times by the reaction of dimedone and 2-naphthol with various aromatic aldehydes under solvent-free conditions. The catalyst coluld be easily recovered using an external magnet and reused for six cycles with almost consistent activity.

  12. 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.

  13. Monodispersed Silica Nanospheres Encapsulating Fe3O4 and LaF3:Eu3+ Nanoparticles for MRI Contrast Agent and Luminescent Imaging

    Science.gov (United States)

    Tian, Yang; Yu, Binbin; Yang, Hong-Yu; Liao, Ji

    2013-03-01

    Bifunctional nanospheres of silica encapsulating Fe3O4 and LaF3:Eu nanoparticles were synthesized in a reverse microemulsion solution. The nanospheres were perfectly monodispersed with a small diameter of 20 nm. The composition of the bifunctional nanospheres was confirmed by powder X-ray diffraction. Their magnetic and luminescent properties were measured at room temperature. The relaxation efficiency and T2-weighted images showed the high-performance for the product as a resonance imaging contrast agent. In addition, a qualitative cell uptake in human cervical cancer HeLa cells demonstrated that the SFLE nanospheres were efficiently up-taken into cytosol. Taken together, these findings suggest that the SiO2/Fe3O4-LaF3:Eu3+ nanospheres are good luminescence probes for bio-imaging.

  14. A highly selective photoelectrochemical biosensor for uric acid based on core-shell Fe3O4@C nanoparticle and molecularly imprinted TiO2.

    Science.gov (United States)

    Zhang, Chunjing; Si, Shihui; Yang, Zhengpeng

    2015-03-15

    Combining the surface modification and molecular imprinting technique, a novel photoelectrochemical sensing platform with excellent photochemical catalysis and molecular recognition capabilities was established for the detection of uric acid based on the magnetic immobilization of Fe3O4@C nanoparticles onto magnetic glassy carbon electrode (MGCE) and modification of molecularly imprinted TiO2 film on Fe3O4@C. The developed biosensor was highly sensitive to uric acid in solutions, with a linear range from 0.3 to 34µM and a limit of detection of 0.02μM. Furthermore, the biosensor exhibited outstanding selectivity while used in coexisting systems containing various interferents with high concentration. The practical application of the biosensor was also realized for the selective detection of uric acid in spiked samples. The study made a successful attempt in the development of highly selective and sensitive photoelectrochemical biosensor for urine monitoring.

  15. Fabrication of Pd Nanoparticles Embedded C@Fe3O4 Core-Shell Hybrid Nanospheres: An Efficient Catalyst for Cyanation in Aryl Halides.

    Science.gov (United States)

    Suresh Kumar, Basuvaraj; Amali, Arlin Jose; Pitchumani, Kasi

    2015-10-21

    Isolated chemical reactors were fabricated by integrating catalytically active sites (Pd) with magnetic functionality (Fe3O4) along with carbon while preserving the constituents functional properties to realize the structure-property relationship of Pd by comparing the catalytic activity of spherical Pd NPs with cubical Pd NPs for cyanation in aryl halides using K4[Fe(CN)6] as a green cyanating agent to yield corresponding nitriles. The superior catalytic reactivity of the cubical Pd NPs is attributed to the larger number of {100} surface facets. The TEM images of reused catalyst shows the change in structure from cubical to spherical nanoparticles, attributed to the efficient leaching susceptibility of Pd {100} surface facets. The cubical Pd NPs on carbon@Fe3O4 is attractive in view of its high catalytic efficiency, easy synthesis, magnetic separability, environmental friendliness, high stability, gram scale applicability, and reusability.

  16. 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.

  17. 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.

  18. In-tube magnetic solid phase microextraction of some fluoroquinolones based on the use of sodium dodecyl sulfate coated Fe3O4 nanoparticles packed tube.

    Science.gov (United States)

    Manbohi, Ahmad; Ahmadi, Seyyed Hamid

    2015-07-23

    In-tube magnetic solid phase microextraction (in-tube MSPME) of fluoroquinolones from water and urine samples based on the use of sodium dodecyl sulfate (SDS) coated Fe3O4 nanoparticles packed tube has been reported. After the preparation of Fe3O4 nanoparticles (NPs) by a batch synthesis, these NPs were introduced into a stainless steel tube by a syringe and then a strong magnet was placed around the tube, so that the Fe3O4 NPs were remained in the tube and the tube was used in the in-tube SPME-HPLC/UV for the analysis of fluoroquinolones in water and urine samples. Plackett-Burman design was employed for screening the variables significantly affecting the extraction efficiency. Then, the significant factors were more investigated by Box-Behnken design. Calibration curves were linear (R(2)>0.990) in the range of 0.1-1000μgL(-1) for ciprofloxacin (CIP) and 0.5-500μgL(-1) for enrofloxacin (ENR) and ofloxacin (OFL), respectively. LODs for all studied fluoroquinolones ranged from 0.01 to 0.05μgL(-1). The main advantages of this method were rapid and easy automation and analysis, short extraction time, high sensitivity, possibility of fully sorbent collection after analysis, wide linear range and no need to organic solvents in extraction. Copyright © 2015 Elsevier B.V. All rights reserved.

  19. A novel europium-sensitive fluorescent nano-chemosensor based on new functionalized magnetic core-shell Fe3O4@SiO2 nanoparticles.

    Science.gov (United States)

    Ganjali, Mohammad Reza; Hosseini, Morteza; Khobi, Mehdi; Farahani, Shima; Shaban, Masoom; Faridbod, Farnoush; Shafiee, Abbas; Norouzi, Parviz

    2013-10-15

    A novel Eu(3+)-sensitive fluorescent chemosensor is introduced. It is based on magnetic core-shell silica nanoparticle which is functionalized by Cinchonidine (CD-Fe3O4@SiO2). The nano-chemosensor was synthesized and characterized by Fourier transform infrared spectroscopy (FT-IR), thermal gravimetric analysis (TGA), transmission electron microscopy (TEM), scanning electron microscopy (SEM), UV-visible absorption and fluorescence emission. The fluorescent nano-chemosensor shows a selective interaction with Eu(3+) ion. Fluorescence studies revealed that the emission intensity of the functionalized magnetic core-shell silica nanoparticles (CD-Fe3O4@SiO2 NPs) increases significantly by addition of various concentrations of Eu(3+) ion. While in case of mono, di, and other trivalent cations, weak changes or either no changes in intensity were observed. The enhancement in fluorescence intensity of nano-chemosensor is because of the strong covalent binding of Eu(3+) ion to CD-Fe3O4@SiO2 NPs with a large binding constant value of 1.7 × 10(5) mol L(-1).

  20. 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.

  1. 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.

  2. 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.

  3. Effect of annealing time on structural and magnetic properties of laser ablated oriented Fe3O4 thin films deposited on Si(100)

    Indian Academy of Sciences (India)

    Shahid M Ramay; Saadat A Siddiqi; M Sabieh Anwar; C Y Park; S-C Shin

    2012-08-01

    We have fabricated ∼143nm Fe3O4 thin films on Si(100) substrates at 450°C and then annealed them at the same temperature for 30, 60 and 90 min under a vacuum of 10-6 torr with pulsed laser deposition. We studied the effects on the structural and magnetic properties of Fe3O4 thin films. The films have been characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM) and vibrating sample magnetometry (VSM). XRD studies showed pure single phase spinel cubic structure of Fe3O4 with a preferential [111] orientation, independent of substrate orientation at 90 min annealing. Higher magnetization was obtained up to 60 min annealing due to Fe phase but at 90 min, we obtained reduced magnetization of 335 emu/cc. This is attributed to the formation of antiphase boundaries between substrate and film.

  4. 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

  5. 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.

  6. 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.

  7. Study of magnetic and structural and optical properties of Zn doped Fe3O4 nanoparticles synthesized by co-precipitation method for biomedical application

    Directory of Open Access Journals (Sweden)

    Zahra Rezay Marand

    2014-09-01

    Full Text Available Abstract Objective(s: This paper describes synthesizing of magnetic nanocomposite with co-precipitation method. Materials and Methods: Magnetic ZnxFe3-xO4 nanoparticles with 0-14% zinc doping (x=0, 0.025, 0.05, 0.075, 0.1 and 0.125 were successfully synthesized by co-precipitation method. The prepared zinc-doped Fe 3O4 nanoparticles were characterized by X-ray diffraction (XRD, transmission electron microscopy (TEM, Fourier transform infrared spectroscopy (FTIR, vibrating sample magnetometer (VSM and UV-Vis spectroscopy. Results: results obtained from X-ray diffraction pattern have revealed the formation of single phase nanoparticles with cubic inverse spinal structures which size varies from 11.13 to 12.81 nm. The prepared nanoparticles have also possessed superparamagnetic properties at room temperature and high level of saturation magnetization with the maximum level of 74.60 emu/g for x=0.075. Ms changing in pure magnetite nanoparticles after impurities addition were explained based on two factors of “particles size” and “exchange interactions”. Optical studies results revealed that band gaps in all Zn-doped NPs are higher than pure Fe 3O4. As doping percent increases, band gap value decreases from 1.26 eV to 0.43 eV. Conclusion: these magnetic nanocomposite structures since having superparamagnetic property offer a high potential for biosensing and biomedical application.

  8. 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.

  9. Origin of the large dispersion of magnetic properties in nanostructured oxides: FexO/Fe3O4 nanoparticles as a case study

    Science.gov (United States)

    Estrader, Marta; López-Ortega, Alberto; Golosovsky, Igor V.; Estradé, Sònia; Roca, Alejandro G.; Salazar-Alvarez, German; López-Conesa, Lluís; Tobia, Dina; Winkler, Elin; Ardisson, José D.; Macedo, Waldemar A. A.; Morphis, Andreas; Vasilakaki, Marianna; Trohidou, Kalliopi N.; Gukasov, Arsen; Mirebeau, Isabelle; Makarova, O. L.; Zysler, Roberto D.; Peiró, Francesca; Baró, Maria Dolors; Bergström, Lennart; Nogués, Josep

    2015-02-01

    The intimate relationship between stoichiometry and physicochemical properties in transition-metal oxides makes them appealing as tunable materials. These features become exacerbated when dealing with nanostructures. However, due to the complexity of nanoscale materials, establishing a distinct relationship between structure-morphology and functionalities is often complicated. In this regard, in the FexO/Fe3O4 system a largely unexplained broad dispersion of magnetic properties has been observed. Here we show, thanks to a comprehensive multi-technique approach, a clear correlation between the magneto-structural properties in large (45 nm) and small (9 nm) FexO/Fe3O4 core/shell nanoparticles that can explain the spread of magnetic behaviors. The results reveal that while the FexO core in the large nanoparticles is antiferromagnetic and has bulk-like stoichiometry and unit-cell parameters, the FexO core in the small particles is highly non-stoichiometric and strained, displaying no significant antiferromagnetism. These results highlight the importance of ample characterization to fully understand the properties of nanostructured metal oxides.The intimate relationship between stoichiometry and physicochemical properties in transition-metal oxides makes them appealing as tunable materials. These features become exacerbated when dealing with nanostructures. However, due to the complexity of nanoscale materials, establishing a distinct relationship between structure-morphology and functionalities is often complicated. In this regard, in the FexO/Fe3O4 system a largely unexplained broad dispersion of magnetic properties has been observed. Here we show, thanks to a comprehensive multi-technique approach, a clear correlation between the magneto-structural properties in large (45 nm) and small (9 nm) FexO/Fe3O4 core/shell nanoparticles that can explain the spread of magnetic behaviors. The results reveal that while the FexO core in the large nanoparticles is

  10. The sandwich-type electrochemiluminescence immunosensor for α-fetoprotein based on enrichment by Fe3O4-Au magnetic nano probes and signal amplification by CdS-Au composite nanoparticles labeled anti-AFP.

    Science.gov (United States)

    Zhou, Hankun; Gan, Ning; Li, Tianhua; Cao, Yuting; Zeng, Saolin; Zheng, Lei; Guo, Zhiyong

    2012-10-09

    A novel and sensitive sandwich-type electrochemiluminescence (ECL) immunosensor was fabricated on a glassy carbon electrode (GCE) for ultra trace levels of α-fetoprotein (AFP) based on sandwich immunoreaction strategy by enrichment using magnetic capture probes and quantum dots coated with Au shell (CdS-Au) as the signal tag. The capture probe was prepared by immobilizing the primary antibody of AFP (Ab1) on the core/shell Fe(3)O(4)-Au nanoparticles, which was first employed to capture AFP antigens to form Fe(3)O(4)-Au/Ab1/AFP complex from the serum after incubation. The product can be separated from the background solution through the magnetic separation. Then the CdS-Au labeled secondary antibody (Ab2) as signal tag (CdS-Au/Ab2) was conjugated successfully with Fe(3)O(4)-Au/Ab1/AFP complex to form a sandwich-type immunocomplex (Fe(3)O(4)-Au/Ab1/AFP/Ab2/CdS-Au), which can be further separated by an external magnetic field and produce ECL signals at a fixed voltage. The signal was proportional to a certain concentration range of AFP for quantification. Thus, an easy-to-use immunosensor with magnetic probes and a quantum dots signal tag was obtained. The immunosensor performed at a level of high sensitivity and a broad concentration range for AFP between 0.0005 and 5.0 ng mL(-1) with a detection limit of 0.2 pg mL(-1). The use of magnetic probes was combined with pre-concentration and separation for trace levels of tumor markers in the serum. Due to the amplification of the signal tag, the immunosensor is highly sensitive, which can offer great promise for rapid, simple, selective and cost-effective detection of effective biomonitoring for clinical application.

  11. In situ ultrasound-assisted preparation of Fe3O4@MnO2 core-shell nanoparticles integrated with ion co-precipitation for multielemental analysis by total reflection X-ray fluorescence

    Science.gov (United States)

    Nourbala-Tafti, Elaheh; Romero, Vanesa; Lavilla, Isela; Dadfarnia, Shayesteh; Bendicho, Carlos

    2017-05-01

    In this work, a new analytical approach based on in situ ultrasound-assisted preparation of manganese dioxide coated magnetite nanoparticles (Fe3O4@MnO2 NPs) was applied for extraction and preconcentration of Ni, Cu, Zn, Tl, Pb, Bi and Se. The Fe3O4@MnO2 core-shell nanocomposite was synthesized by application of high-intensity sonication to an aqueous reaction medium in the presence of the target analytes, which are trapped during NPs formation. In this way, synthesis of the nanosorbent and extraction can be simultaneously accomplished within only 30 s. After the extraction step, the resulting Fe3O4@MnO2 NPs enriched with the target analytes were separated by an external magnetic field, so that filtration or centrifugation steps were unnecessary. A 10 μL aliquot of the solid phase was deposited onto a sample carrier (quartz reflector) and directly analyzed by total-reflection X-ray fluorescence (TXRF) without the need for an elution step. A comprehensive characterization of the Fe3O4@MnO2 NPs was carried out by transmission electron microscopy and TXRF. Detection limits ranged from 0.19 to 0.98 μg L- 1 depending on the analyte. Enrichment factors in the range of 402-540 were obtained. The repeatability expressed as relative standard deviation was around 1.7% (N = 5). The accuracy of the proposed method was assessed by analyzing the certified reference material BCR®-610 (groundwater). An effective, simple, rapid and sensitive procedure for multielemental analysis of water samples was accomplished.

  12. Conductive Fe3O4 nanoparticles accelerate syntrophic methane production from butyrate oxidation in two different lake sediments

    Directory of Open Access Journals (Sweden)

    Jianchao Zhang

    2016-08-01

    Full Text Available 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 (CNTs in the sediment enrichments. Observations made with fluorescence in situ hybridization (FISH and scanning electron microscope (SEM 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.

  13. 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

  14. Synergistic effect of a combination of nanoparticulate Fe3O4 and gambogic acid on phosphatidylinositol 3-kinase/Akt/Bad pathway of LOVO cells

    OpenAIRE

    Hu S; Xia G; Tian Y; Cai X.; Fang L; Wang R; Chen B; Liu S

    2012-01-01

    Lianghua Fang,1,3 Baoan Chen,2 Shenlin Liu,3 Ruiping Wang,3 Shouyou Hu,3 Guohua Xia,2 Yongli Tian,3 Xiaohui Cai21No 1 Clinical Medical College of Nanjing University of Chinese Medicine, 2Department of Hematology, Zhongda Hospital, Medical School, Southeast University, 3Department of Oncology, Jiangsu Province Hospital of Traditional Chinese Medicine, Nanjing, People's Republic of ChinaBackground: The present study evaluated whether magnetic nanoparticles containing Fe3O4 could enhance...

  15. 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.

  16. 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

  17. Effect of nanographene platelets (NGP) surface area on organic dye adsorption using Fe3O4-NGP composites

    Science.gov (United States)

    Taufik, A.; Saleh, R.

    2016-11-01

    Fe3O4-NanoGraphene Platelets (NGP) composites with different surface area were successfully synthesized using sol gel method. The inverse cubic spinel structures as well as graphitic like structure from NGP were detected using X-Ray Diffraction (XRD) Measurement, while the ferromagnetic behavior for all samples were detected using Vibrating Sample Magnetometry (VSM) measurement. The vibrational mode for all samples were characterized using Fourier Transform Infrared Spectroscopy (FT-IR), and thermal stability for all samples were characterized using Thermogravimetric Analysis (TGA). The adsorption process were tested using methylene blue (MB) as a model of organic pollutant. The result showed that the higher NGP surface area could enhance the adsorption capacity of the samples. The kinetic model of adsorption shows that the adsorption process of Fe3O4-NGP materials followed the second order kinetic reaction. The reusability of adsorbent were also performed to analyze the stability of the adsorbent.

  18. Origin of the large dispersion of magnetic properties in nanostructured oxides: Fe(x)O/Fe3O4 nanoparticles as a case study.

    Science.gov (United States)

    Estrader, Marta; López-Ortega, Alberto; Golosovsky, Igor V; Estradé, Sònia; Roca, Alejandro G; Salazar-Alvarez, German; López-Conesa, Lluís; Tobia, Dina; Winkler, Elin; Ardisson, José D; Macedo, Waldemar A A; Morphis, Andreas; Vasilakaki, Marianna; Trohidou, Kalliopi N; Gukasov, Arsen; Mirebeau, Isabelle; Makarova, O L; Zysler, Roberto D; Peiró, Francesca; Baró, Maria Dolors; Bergström, Lennart; Nogués, Josep

    2015-02-21

    The intimate relationship between stoichiometry and physicochemical properties in transition-metal oxides makes them appealing as tunable materials. These features become exacerbated when dealing with nanostructures. However, due to the complexity of nanoscale materials, establishing a distinct relationship between structure-morphology and functionalities is often complicated. In this regard, in the FexO/Fe3O4 system a largely unexplained broad dispersion of magnetic properties has been observed. Here we show, thanks to a comprehensive multi-technique approach, a clear correlation between the magneto-structural properties in large (45 nm) and small (9 nm) FexO/Fe3O4 core/shell nanoparticles that can explain the spread of magnetic behaviors. The results reveal that while the FexO core in the large nanoparticles is antiferromagnetic and has bulk-like stoichiometry and unit-cell parameters, the FexO core in the small particles is highly non-stoichiometric and strained, displaying no significant antiferromagnetism. These results highlight the importance of ample characterization to fully understand the properties of nanostructured metal oxides.

  19. 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.

  20. Preparation of amino-functionalized Fe3O4@mSiO2 core-shell magnetic nanoparticles and their application for aqueous Fe(3+) removal.

    Science.gov (United States)

    Meng, Cheng; Zhikun, Wang; Qiang, Lv; Chunling, Li; Shuangqing, Sun; Songqing, Hu

    2018-01-05

    Fe3O4 nanoparticle with magnetic properties and nanoscale features has provoked wide research interest and great potential application. Herein, a modified Stober and template-removing method was adopted to prepare magnetic mesoporous silica nanoparticles (MSNs), comprising a Fe3O4 core and a mesoporous silica shell. The shell was functionalized by amino-groups with tunable removal efficiency for aqueous heavy metals ions. Structural and magnetic properties were characterized by XRD, SEM, FT-IR, vibrating sample magnetometer (VSM) and BET (Brunauer-Emmertt-Teller) techniques. Also, the adsorbing efficiency for heavy metal ions was measured by UV-vis spectrometry. Results revealed that the pure magnetite is cubic with a side length of 40 - 70nm, while the silica-coated magnetite is spherical with a diameter of 220-260nm. The mesoporous silica shell has an average pore size of 2.6nm and a high surface area of 675m(2)·g(-1), which lead to a large adsorption capacity for Fe(3+) (up to 20.66mg of Fe per g of adsorbent). Moreover, rapid magnetic separation and regeneration of as-prepared adsorbent were achieved conveniently. The distinctive structure and the heavy metal ions removal property of magnetic nanocomposites reflect their prospective application in water treatment. Copyright © 2017 Elsevier B.V. All rights reserved.

  1. Exchange-coupled fct-FePd/α-Fe nanocomposite magnets converted from Pd/Fe3O4 core/shell nanoparticles.

    Science.gov (United States)

    Liu, Fei; Dong, Yunhe; Yang, Wenlong; Yu, Jing; Xu, Zhichuan; Hou, Yanglong

    2014-11-10

    We report the controlled synthesis of exchange-coupled face-centered tetragonal (fct) FePd/α-Fe nanocomposite magnets with variable Fe concentration. The composite was converted from Pd/Fe3O4 core/shell nanoparticles through a high-temperature annealing process in a reducing atmosphere. The shell thickness of core/shell Pd/Fe3O4 nanoparticles could be readily tuned, and subsequently the concentration of Fe in nanocomposite magnets was controlled. Upon annealing reduction, the hard magnetic fct-FePd phase was formed by the interdiffusion between reduced α-Fe and face-centered cubic (fcc) Pd, whereas the excessive α-Fe remained around the fct-FePd grains, realizing exchange coupling between the soft magnetic α-Fe and hard magnetic fct-FePd phases. Magnetic measurements showed variation in the magnetic properties of the nanocomposite magnets with different compositions, indicating distinct exchange coupling at the interfaces. The coercivity of the exchange-coupled nanocomposites could be tuned from 0.7 to 2.8 kOe and the saturation magnetization could be controlled from 93 to 160 emu g(-1). This work provides a bottom-up approach using exchange-coupled nanocomposites for engineering advanced permanent magnets with controllable magnetic properties.

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

    Science.gov (United States)

    Yang, Cuiping; He, Xiangfeng; Chen, Junsong; Chen, Dengyu; Liu, Yunjing; Xiong, Fei; Shi, Fangfang; Dou, Jun; Gu, Ning

    2013-08-01

    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.

  3. Convenient on water synthesis of novel derivatives of dicoumarol as functional vitamin K depleter by Fe3O4 magnetic nanoparticles

    Directory of Open Access Journals (Sweden)

    Saeed Khodabakhshi

    2017-05-01

    Full Text Available The Fe3O4 nanoparticles were successfully prepared and characterized by X-ray diffraction (XRD, Fourier transform-infrared (FT-IR, and transmission electron microscopy (TEM. The magnetic property of the prepared nanoparticles was investigated by magnetization analysis and the measured magnetization of NPs was found to be considerably lower than the values measured from bulk magnetite. The catalytic efficiency of the prepared nanoparticles was subsequently investigated as a magnetically recyclable and safe catalyst for the green synthesis of new dicoumarols via the one-pot condensation of 4-hydroxycoumarin with aryl glyoxals on water. Catalyst loadings can be as low as 2 mol% to give good yields of the corresponding products. This present method has many advantages, such as the high product yield, avoidance of toxic organic solvents, and simple work-up procedure.

  4. Mössbauer and X-ray study of biodegradation of 57Fe3 O 4 magnetic nanoparticles in rat brain

    Science.gov (United States)

    Gabbasov, R. R.; Cherepanov, V. M.; Chuev, M. A.; Lomov, A. A.; Mischenko, I. N.; Nikitin, M. P.; Polikarpov, M. A.; Panchenko, V. Y.

    2016-12-01

    Biodegradation of a 57Fe3 O 4 - based dextran - stabilized ferrofluid in the ventricular cavities of the rat brain was studied by X-ray diffraction and Mössbauer spectroscopy. A two-step process of biodegradation, consisting of fast disintegration of the initial composite magnetic beads into separate superparamagnetic nanoparticles and subsequent slow dissolution of the nanoparticles has been found. Joint fitting of the couples of Mössbauer spectra measured at different temperatures in the formalism of multi-level relaxation model with one set of fitting parameters, allowed us to measure concentration of exogenous iron in the rat brain as a function of time after the injection of nanoparticles.

  5. 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.

  6. 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.

  7. 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.

  8. 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.

  9. Film fabrication of Fe or Fe3O4 nanoparticles mixed with palmitic acid for vertically aligned carbon nanotube growth using Langmuir-Blodgett technique

    Science.gov (United States)

    Nakamura, Kentaro; Kuriyama, Naoki; Takagiwa, Shota; Sato, Taiga; Kushida, Masahito

    2016-03-01

    Vertically aligned carbon nanotubes (VA-CNTs) were studied as a new catalyst support for polymer electrolyte fuel cells (PEFCs). Controlling the number density and the diameter of VA-CNTs may be necessary to optimize PEFC performance. As the catalyst for CNT growth, we fabricated Fe or Fe3O4 nanoparticle (NP) films by the Langmuir-Blodgett (LB) technique. The catalyst Fe or Fe3O4 NPs were widely separated by mixing with filler molecules [palmitic acid (C16)]. The number density of VA-CNTs was controlled by varying the ratio of catalyst NPs to C16 filler molecules. The VA-CNTs were synthesized from the catalyst NP-C16 LB films by thermal chemical vapor deposition (CVD) using acetylene gas as the carbon source. The developing solvents used in the LB technique and the hydrogen reduction conditions of CVD were optimized to improve the VA-CNT growth rate. We demonstrate that the proposed method can independently control both the density and the diameter of VA-CNTs.

  10. 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.

  11. 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.

  12. 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.

  13. Synthesis of DNPH/SDS/Fe3O4 Nanoparticles for Removal of Cr (VI Ions From Aqueous Solution

    Directory of Open Access Journals (Sweden)

    Soheil Sobhanardakani

    2016-06-01

    Full Text Available In this study, sodium dodecyl sulfate (SDS coated magnetite modified with 2, 4-Dinitrophenylhydrazine was used to remove Cr (VI ions from aqueous solution. The modified magnetite nanoparticles were characterized by X-ray diffraction (XRD analysis, Fourier transform infrared spectroscopy (FT-IR, scanning electron microscopy (SEM, and SEM–EDXS measurement. The synthesized nanoparticles exhibited a high surface area of 75.5 m2 g−1 and were of 20 - 35 nm in particle size. The effects of parameters, including pH, dose of adsorbent, temperature and contact time were investigated to find the optimum adsorption conditions. Adsorption data fits well with the Langmuir isotherm model with a maximum adsorption capacity (qm and a Langmuir adsorption equilibrium constant (b of 169.5 mg g-1 and 0.168 L mg-1, respectively. The adsorption kinetic agrees well with pseudo-second-order model.

  14. 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.

  15. 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.

  16. Preparation of Fe3O4 nanoparticles by impinging stream reactor%撞击流反应器制备纳米四氧化三铁的研究

    Institute of Scientific and Technical Information of China (English)

    刘东; 林修洲; 朱想明; 罗晓刚

    2011-01-01

    In submerged circulative impinging stream reactor, Fe3O4 nanoparticles were prepared by co-precipitation method,with FeSO4 · 7H2O and FeCl3 · 6H2O as raw materials,and ammonia as precipitator. Effects of stirring rate,amount-of-substance ratio of Fe2+ to Fe3+ , reaction temperature,and pH on dispersion and particle size of Fe3 O4 nanoparticles were investigated. Structure and performance of Fe3O4 nanoparticles were characterized by Fourier transform infrared spectroscopy (FT- IR) ,transmission electron microscopy (TEM) ,and X- ray diffraction (XRD). Results showed that Fe3O4 nanoparticles with good dispersion,high purity,and mean particle size of 10 nm could be prepared under following optimum technological conditions: amount-of-substance ratio of Fe2 + to Fe3 + was 1∶1, reaction temperature was 40 ℃, stirring rate was 1 600 r/min, pH was about 11.0 in the presence of ammonia as precipitant.%在浸没式循环撞击流反应器中,以氨水为沉淀剂,用七水合硫酸亚铁和六水合三氯化铁为原料,采用共沉淀法制备了纳米四氧化三铁粒子.考察了搅拌转速、亚铁与三价铁物质的量比、反应温度和溶液pH对所得纳米四氧化三铁的分散性和粒径的影响.采用傅里叶红外光谱仪、透射电镜、X射线衍射仪等对制得的纳米粒子的结构和性能进行了表征.结果表明:用撞击流反应器制备纳米四氧化三铁粒子的最佳工艺条件:亚铁与三价铁物质的量比为1:1,反应温度为40℃,搅拌转速为1 600 r/min,以氨水作沉淀剂,最佳pH控制在11.0左右.在上述条件下,可以制备出分散性好、纯度高、平均粒径为10 nm的四氧化三铁粒子.

  17. Synthesis of Bifunctional Fe3O4@SiO2-Ag Magnetic-Plasmonic Nanoparticles by an Ultrasound Assisted Chemical Method

    Science.gov (United States)

    Chu, Dung Tien; Sai, Doanh Cong; Luu, Quynh Manh; Tran, Hong Thi; Quach, Truong Duy; Kim, Dong Hyun; Nguyen, Nam Hoang

    2017-03-01

    Bifunctional magnetic-plasmonic nanoparticles (NPs)—Fe3O4@SiO2-Ag were successfully synthesized by an ultrasound assisted chemical method. Silver ions were absorbed and then reduced by sodium borohydride on the surface of 3-aminopropyltriethoxysilane (APTES) functionalized silica-coated magnetic NPs, then they were reduced under the influence of a 200 W ultrasonic wave for 60 min. When the amount of precursor silver ions increased, the relative intensity of diffraction peaks of silver crystals in all samples increased with the atomic ratio of silver/iron increasing from 0.208 to 0.455 and saturation magnetization (M s) decreasing from 44.68 emu/g to 34.74 emu/g. The NPs have superparamagnetic properties and strong surface plasmon absorption at 420 nm, which make these particles promising for biomedical applications.

  18. 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.

  19. Synthesis of Bifunctional Fe3O4@SiO2-Ag Magnetic-Plasmonic Nanoparticles by an Ultrasound Assisted Chemical Method

    Science.gov (United States)

    Chu, Dung Tien; Sai, Doanh Cong; Luu, Quynh Manh; Tran, Hong Thi; Quach, Truong Duy; Kim, Dong Hyun; Nguyen, Nam Hoang

    2017-06-01

    Bifunctional magnetic-plasmonic nanoparticles (NPs)—Fe3O4@SiO2-Ag were successfully synthesized by an ultrasound assisted chemical method. Silver ions were absorbed and then reduced by sodium borohydride on the surface of 3-aminopropyltriethoxysilane (APTES) functionalized silica-coated magnetic NPs, then they were reduced under the influence of a 200 W ultrasonic wave for 60 min. When the amount of precursor silver ions increased, the relative intensity of diffraction peaks of silver crystals in all samples increased with the atomic ratio of silver/iron increasing from 0.208 to 0.455 and saturation magnetization ( M s) decreasing from 44.68 emu/g to 34.74 emu/g. The NPs have superparamagnetic properties and strong surface plasmon absorption at 420 nm, which make these particles promising for biomedical applications.

  20. Fe3O4/γ-Fe2O3 nanoparticle multilayers deposited by the Langmuir-Blodgett technique for gas sensors application.

    Science.gov (United States)

    Capone, S; Manera, M G; Taurino, A; Siciliano, P; Rella, R; Luby, S; Benkovicova, M; Siffalovic, P; Majkova, E

    2014-02-04

    Fe3O4/γ-Fe2O3 nanoparticles (NPs) based thin films were used as active layers in solid state resistive chemical sensors. NPs were synthesized by high temperature solution phase reaction. Sensing NP monolayers (ML) were deposited by Langmuir-Blodgett (LB) techniques onto chemoresistive transduction platforms. The sensing ML were UV treated to remove NP insulating capping. Sensors surface was characterized by scanning electron microscopy (SEM). Systematic gas sensing tests in controlled atmosphere were carried out toward NO2, CO, and acetone at different concentrations and working temperatures of the sensing layers. The best sensing performance results were obtained for sensors with higher NPs coverage (10 ML), mainly for NO2 gas showing interesting selectivity toward nitrogen oxides. Electrical properties and conduction mechanisms are discussed.

  1. Silica supported Fe(3)O(4) magnetic nanoparticles for magnetic solid-phase extraction and magnetic in-tube solid-phase microextraction: application to organophosphorous compounds.

    Science.gov (United States)

    Moliner-Martinez, Y; Vitta, Yosmery; Prima-Garcia, Helena; González-Fuenzalida, R A; Ribera, Antonio; Campíns-Falcó, P; Coronado, Eugenio

    2014-03-01

    This work demonstrates the application of silica supported Fe3O4 nanoparticles as sorbent phase for magnetic solid-phase extraction (MSPE) and magnetic on-line in-tube solid-phase microextraction (Magnetic-IT-SPME) combined with capillary liquid chromatography-diode array detection (CapLC-DAD) to determine organophosphorous compounds (OPs) at trace level. In MSPE, magnetism is used as separation tool while in Magnetic-IT-SPME, the application of an external magnetic field gave rise to a significant improvement of the adsorption of OPs on the sorbent phase. Extraction efficiency, analysis time, reproducibility and sensitivity have been compared. This work showed that Magnetic-IT-SPME can be extended to OPs with successful results in terms of simplicity, speed, extraction efficiency and limit of detection. Finally, wastewater samples were analysed to determine OPs at nanograms per litre.

  2. 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.

  3. 纳米Fe3O4对透钙磷石骨水泥的理化性能影响研究%Effect of nano-Fe3O4 on the properties of brushite cements

    Institute of Scientific and Technical Information of China (English)

    李光大; 常乔婉; 赵三团; 麻开旺; 梁高峰; 付传帅; 弓志超; 徐晶伟

    2013-01-01

    将纳米Fe3O4按与透钙磷石骨水泥基质质量比为1∶20、1∶10及1∶5的比例加入,研究对其性能的影响.结果表明,随Fe3O4掺入增多,由于理化结构改变,骨水泥固化时间被延长至约9~27min;固化放热明显降低;可注射性和抗压强度先上升后下降,掺入比为1∶10时,可注射性(可注射系数约89%)及抗压强度(约45MPa)最优,显著高于掺杂前;在1.59×106A/m磁场下,材料饱和磁化强度从0.49A·m2/kg增加到5.51A·m2/kg,矫顽力从233.23A/m增加到707.64A/m;降解速度减缓明显,当掺入比达1∶5时,材料28d浸泡失重率由未掺杂时的约14.9%下降到约7.5%.

  4. 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.

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

    Directory of Open Access Journals (Sweden)

    Hamidreza Kheiri Manjili

    Full Text Available 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.

  6. 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.

  7. Superparamagnetic Iron Oxide (Fe3O4 Nanoparticles Coated with PEG/PEI for Biomedical Applications: A Facile and Scalable Preparation Route Based on the Cathodic Electrochemical Deposition Method

    Directory of Open Access Journals (Sweden)

    Isa Karimzadeh

    2017-01-01

    Full Text Available Cathodic electrochemical deposition (CED is introduced as an efficient and effective method for synthesis and surface coating of superparamagnetic iron oxide nanoparticles (SPIONs. In this way, bare Fe3O4 nanoparticles were electrosynthesized through CED method from aqueous solution Fe3+ : Fe2+ chloride (molar ratio of 2 : 1. In the next step, the surface of NPs was coated with polyethyleneimine (PEI and polyethylene glycol (PEG during the CED procedure, and PEG/PEI coated SPIONs were obtained. The prepared NPs were evaluated by powder X-ray diffraction (XRD, Fourier transform infrared spectroscopy (FTIR, thermogravimetric analysis (TGA, dynamic light scattering (DLS, vibrating sample magnetometer (VSM, and field-emission scanning electron microscopy (FE-SEM. The pure magnetite phase and nanosize (about 15 nm of the prepared NPs were confirmed by XRD and FE-SEM. The presence of two coats (i.e., PEG and PEI on the surface of electrosynthesized NPs was proved via FTIR results. The percentage of polymer coat (37.5% on the NPs surface was provided by TGA analysis. The high magnetization value, negligible coercivity, and remanence measured by VSM indicate the superparamagnetic nature of both prepared NPs. The obtained results confirmed that the prepared Fe3O4 nanoparticles have suitable physicochemical and magnetic properties for biomedical applications.

  8. One-pot preparation of superparamagnetic attapulgite/Fe3O4/polydopamine nanocomposites for adsorption of methylene blue

    Science.gov (United States)

    Mu, Bin; Kang, Yuru; Zheng, Maosong; Wang, Aiqin

    2016-05-01

    Superparamagnetic attapulgite/Fe3O4/polydopamine nanocomposites have been facilely prepared by a one-pot process without the nitrogen protection, in which Fe(III) was served as both of the oxidant for dopamine and the precursor of Fe3O4 in the presence of attapulgite. The introduction of attapulgite can effectively induce the uniform encapsulation of polydopamine and Fe3O4 nanoparticles on the surface of attapulgite, preventing from the formation of the free aggregates of Fe3O4 nanoparticles. The as-prepared APT/Fe3O4/PANI nanocomposites can be used as an adsorbent for the removal of methylene blue, and the adsorption ratio toward 100 ppm of methylene blue could reach 95.8%.

  9. 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.

  10. PLLA- Fe3O4 nanocomposites

    Science.gov (United States)

    Albano, Carmen; Gonzalez, Gema; Naranjo, Claudio

    2012-07-01

    In the present work magnetite nanoparticules and PLLA- Fe3O4 nanocomposites were prepared by high frequency ultrasound. The influence of pH on nanoparticle size was studied, showing that the particle size decreased as the pH increased. In the composites an interaction between the magnetite nanoparticles and the PLLA matrix was observed by FTIR. Magnetic properties were studied using a VSM, and a superparamegnetic behavior was observed for magnetite nanoparticles, but for the composite a magnetic attenuation was observed due to the polymeric matrix.

  11. Antitumor magnetic hyperthermia induced by RGD-functionalized Fe3O4 nanoparticles, in an experimental model of colorectal liver metastases

    Directory of Open Access Journals (Sweden)

    Oihane K. Arriortua

    2016-10-01

    Full Text Available This work reports important advances in the study of magnetic nanoparticles (MNPs related to their application in different research fields such as magnetic hyperthermia. Nanotherapy based on targeted nanoparticles could become an attractive alternative to conventional oncologic treatments as it allows a local heating in tumoral surroundings without damage to healthy tissue. RGD-peptide-conjugated MNPs have been designed to specifically target αVβ3 receptor-expressing cancer cells, being bound the RGD peptides by “click chemistry” due to its selectivity and applicability. The thermal decomposition of iron metallo-organic precursors yield homogeneous Fe3O4 nanoparticles that have been properly functionalized with RGD peptides, and the preparation of magnetic fluids has been achieved. The nanoparticles were characterized by transmission electron microscopy (TEM, vibrating sample magnetometry (VSM, electron magnetic resonance (EMR spectroscopy and magnetic hyperthermia. The nanoparticles present superparamagnetic behavior with very high magnetization values, which yield hyperthermia values above 500 W/g for magnetic fluids. These fluids have been administrated to rats, but instead of injecting MNP fluid directly into liver tumors, intravascular administration of MNPs in animals with induced colorectal tumors has been performed. Afterwards the animals were exposed to an alternating magnetic field in order to achieve hyperthermia. The evolution of an in vivo model has been described, resulting in a significant reduction in tumor viability.

  12. 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.

  13. 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.

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

    OpenAIRE

    Catalayud, M. P.; Sanz, B; 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 si...

  15. Magnetic γ-Fe2O3, Fe3O4, and Fe nanoparticles confined within ordered mesoporous carbons as efficient microwave absorbers.

    Science.gov (United States)

    Wang, Jiacheng; Zhou, Hu; Zhuang, Jiandong; Liu, Qian

    2015-02-07

    A series of magnetic γ-Fe2O3, Fe3O4, and Fe nanoparticles have been successfully introduced into the mesochannels of ordered mesoporous carbons by the combination of the impregnation of iron salt precursors and then in situ hydrolysis, pyrolysis and reduction processes. The magnetic nanoparticles are uniformly dispersed and confined within the mesopores of mesoporous carbons. Although the as-prepared magnetic mesoporous carbon composites have high contents of magnetic components, they still possess very high specific surface areas and pore volumes. The magnetic hysteresis loops measurements indicate that the magnetic constituents are poorly-crystalline nanoparticles and their saturation magnetization is evidently smaller than bulky magnetic materials. The confinement of magnetic nanoparticles within the mesopores of mesoporous carbons results in the decrease of the complex permittivity and the increase of the complex permeability of the magnetic nanocomposites. The maximum reflection loss (RL) values of -32 dB at 11.3 GHz and a broad absorption band (over 2 GHz) with RL values magnetic mesoporous carbon composites as high-performance microwave absorbing materials.

  16. 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.

  17. Extraction of Genomic DNA Using Magnetic Nanoparticles (Fe3O4 as a Solid-Phase Support

    Directory of Open Access Journals (Sweden)

    Z. M. Saiyed

    2007-01-01

    Full Text Available Magnetic separation technology, using magnetic particles, is quick and easy method for sensitive and reliable captures of specific proteins, genetic material and other biomolecules. The current paper describes a universal genomic DNA extraction method optimized in our laboratory using magnetic nanoparticles as a solid phase adsorbent. The yields of the isolated DNA with magnetic method were higher or equivalent to the conventional procedures in all the samples tested. Additionally, the magnetic method takes less than 15 minutes to extract DNA as against several hours taken by conventional protocols. Furthermore, the isolated DNA was found to function satisfactorily in PCR amplification and restriction endonuclease digestion. The developed procedure is simple, quick, cheap, robust and does not require the use of organic solvents or sophisticated equipments; thereby making it more amenable to automation.

  18. One-step hydrothermal synthesis of highly water-soluble secondary structural Fe3O4 nanoparticles

    Science.gov (United States)

    Yang, Xiwen; Jiang, Wei; Liu, Li; Chen, Binghua; Wu, Shixi; Sun, Danping; Li, Fengsheng

    2012-07-01

    Magnetite nanoparticles (MNPs) were prepared using the ferric acetylacetonate as the sole iron source in a facile hydrothermal route, while poly(acrylic acid) (PAA) was chosen as the stabilizer via one-step functionalized MNPs for better hydrophilic properties. The orthogonal was used in the paper for the experimental parameters optimization, including the solvent, the reaction time, the amount of stabilizer and the presynthesis. The obtained highly water dispersible MNPs with uniform size from about 50 to about 100 nm was individually composed of many monodisperse magnetite crystallites approximately 6 nm in size. And the MNPs show high magnetic properties, whose magnetite content was up to 76.76% and the saturation magnetization was 39.0 emu/g. Later the formation mechanism of MNPs was also discussed. Thus the MNPs proved to be very promising for biomedical applications.

  19. Fe3O4@ionic liquid@methyl orange nanoparticles as a novel nano-adsorbent for magnetic solid-phase extraction of polycyclic aromatic hydrocarbons in environmental water samples.

    Science.gov (United States)

    Liu, Xiaofei; Lu, Xin; Huang, Yong; Liu, Chengwei; Zhao, Shulin

    2014-02-01

    A novel nano-adsorbent, Fe3O4@ionic liquid@methyl orange nanoparticles (Fe3O4@IL@MO NPs), was prepared for magnetic solid-phase extraction (MSPE) of polycyclic aromatic hydrocarbons (PAHs) in environmental water samples. The Fe3O4@IL@MO NPs were synthesized by self-assembly of the ionic liquid 1-octadecyl-3-methylimidazolium bromide (C18mimBr) and methyl orange (MO) onto the surface of Fe3O4 silica magnetic nanoparticles, as confirmed by infrared spectroscopy, ultraviolet-visible spectroscopy and superconducting quantum interface device magnetometer. The extraction performance of Fe3O4@IL@MO NPs as a nano-adsorbent was evaluated by using five PAHs, fluorene (FLu), anthracene (AnT), pyrene (Pyr), benzo(a)anthracene (BaA) and benzo(a)pyrene (BaP) as model analytes. Under the optimum conditions, detection limits in the range of 0.1-2 ng/L were obtained by high performance liquid chromatography-fluorescence detection (HPLC-FLD). This method has been successfully applied for the determination of PAHs in environmental water samples by using the MSPE-HPLC-FLD. The recoveries for the five PAHs tested in spiked real water samples were in the range of 80.4-104.0% with relative standard deviations ranging from 2.3 to 4.9%.

  20. 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.

  1. 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

  2. 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.

  3. 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...

  4. Cytotoxicity and genotoxicity of GO-Fe3O4 hybrid in cultured mammalian cells

    Directory of Open Access Journals (Sweden)

    Jedrzejczak-Silicka Magdalena

    2017-03-01

    Full Text Available The study was aimed at investigating the effect of the Fe3O4 hybrid deposited on graphene oxide (GO-Fe3O4 on the relative viability and DNA integrity. The properties of the GO-Fe3O4 hybrid were analyzed using a transmission electron microscopy (TEM, X-ray diffraction technique (XRD and thermal gravimetric method (TGA, while the efficiency of graphene oxide covalent functionalization with iron oxide nanospheres was determined by Fourier transform infrared spectroscopy (FT-IR. L929 and MCF-7 cell lines were selected to analyze the biocompatibility of GO-Fe3O4 nanoparticles. The hybrid was tested using WST-1 and LDH leakage assays. DNA integrity was analyzed by agarose gel electrophoresis and micronucleus assay was performed to examine chromosomal damage in the exposed cell lines. The tested GO-Fe3O4 hybrid did not significantly reduce cell metabolism of L929 cells. GO-Fe3O4 hybrid particles only slightly affected the integrity of cell membranes. DNA integrity and micronucleus assays did not indicate genotoxicity of the hybrid.

  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

    2016-03-07

    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.

  6. 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.

  7. Preparation, characterization and PEGylation of superparamagnetic Fe3O4 nanoparticles from ethanol medium via cathodic electrochemical deposition (CED) method

    Science.gov (United States)

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

    2016-09-01

    In this study, we report a practical and effective synthetic method for preparation of naked and polymer coated SPIONs. In this method, naked SPIONs with proper superparamagnetic properties (Ms = 62.9 emu g-1, Mr = 0.75 emu g-1 and Hc = 2.3 Oe) were electrochemically deposited by adjusting optimum electrochemical conditions. Then, polyethylene glycol (PEG) was in situ coated on the SPIONs surface during their electrochemical preparation process. The PEG coat of SPIONs was confirmed by FT-IR, DLS and DSC-TG analyses. The magnetic analysis via VSM revealed that the PEGylated SPIONs have suitable superparamagnetic behavior (Ms = 37.5 emu g-1, Mr = 0.27 emu g-1 and Hc = 1.4 Oe). Based on the obtained results, it was stated that this electrochemical strategy opens a great window for preparation of SPIONs coated with various biocompatible polymers.

  8. Fe3O4@rGO复合磁性粒子对聚氨酯弹性体复合材料性能的影响%Effects of Fe3O4@rGO Composite Magnetic Particles on Properties of Polyurethane Composites

    Institute of Scientific and Technical Information of China (English)

    池慧娟; 孙友谊; 于海林; 刘坦坦; 张文辉; 侯春林; 刘亚青

    2015-01-01

    Three kinds of polyurethane(PUR) elastomer/Fe3O4@reduced graphene oxide(rGO) composites were prepared by incorporating Fe3O4@rGO–tetrahydrofuran(THF) dispersion into PUR elastomer matrix using in-situ polymerization method. The components of the PUR elastomer and PUR/Fe3O4@rGO elastomer composites were characterized by XRD,and the disperse situation was studied by SEM. In addition,the effects of Fe3O4@rGO composite magnetic particles on the thermal,magnetic and mechanical properties of the composite were further investigated in detail. It is found that the Fe3O4@rGO composite magnetic particles have great effects on the properties of the composites. The magnetic,thermal and mechanical properties of the composites are all improved at low loading of 0.5%. At the same time,with the increase of the rGO amount in Fe3O4@rGO composite magnetic particles,the saturation magnetization of the corresponding magnetic composites decrease,and the thermal stability and mechanical properties are gradually increased. When the rGO content in Fe3O4@rGO composite magnetic particles accounted for 60%,PUR/ Fe3O4@rGO composites show higher mechanical properties,which the tensile strength,the elongation at break,the tensile elastic modulus,the glass transition temperature,the maximum loss factor and the storage modulus at–60℃are up to 35.31 MPa, 438.90%,86.42 MPa,10.64℃,0.41 and 3 805.84 MPa,respectively. In addition,Fe3O4@rGO composite magnetic particles have good dispersion in PUR elastomer matrix.%将3种不同的Fe3O4@还原氧化石墨烯(rGO)–四氢呋喃(THF)复合磁性粒子分散液分别与聚氨酯(PUR)弹性体进行原位聚合制备3种PUR弹性体/Fe3O4@rGO磁性复合材料,并对其组分和分散状态进行了表征,系统研究了Fe3O4@rGO复合磁性粒子对PUR弹性体磁性能、热性能和力学性能的影响。结果表明,仅掺入质量分数为0.5%的Fe3O4@rGO复合磁性粒子可以显著提高PUR弹性体的性能。随着Fe3O4@r

  9. Paclitaxel-Fe3O4 nanoparticles inhibit growth of CD138–  CD34– tumor stem-like cells in multiple myeloma-bearing mice

    Directory of Open Access Journals (Sweden)

    Yang C

    2013-04-01

    Full Text Available Cuiping Yang,1,3,* Jing Wang,2,* Dengyu Chen,1,* Junsong Chen,1 Fei Xiong,4 Hongyi Zhang,1 Yunxia Zhang,2 Ning Gu,4 Jun Dou11Department of Pathogenic Biology and Immunology, Medical School, 2Department of Gynecology and Obstetrics, Zhongda Hospital, Southeast University, Nanjing, 3Department of Pathogenic Biology and Immunology, School of Basic Medicine, Jiangxi University of Traditional Chinese Medicine, Nanchang, 4School of Biological Science and Medical Engineering, Southeast University, Nanjing, People’s Republic of China*These authors contributed equally to this workBackground: There is growing evidence that CD138– CD34– cells may actually be tumor stem cells responsible for initiation and relapse of multiple myeloma. However, effective drugs targeted at CD138– CD34– tumor stem cells are yet to be developed. The purpose of this study was to investigate the inhibitory effect of paclitaxel-loaded Fe3O4 nanoparticles (PTX-NPs on CD138– CD34– tumor stem cells in multiple myeloma-bearing mice.Methods: CD138– CD34– cells were isolated from a human U266 multiple myeloma cell line using an immune magnetic bead sorting method and then subcutaneously injected into mice with nonobese diabetic/severe combined immunodeficiency to develop a multiple myeloma-bearing mouse model. The mice were treated with Fe3O4 nanoparticles 2 mg/kg, paclitaxel 4.8 mg/kg, and PTX-NPs 0.64 mg/kg for 2 weeks. Tumor growth, pathological changes, serum and urinary interleukin-6 levels, and molecular expression of caspase-3, caspase-8, and caspase-9 were evaluated.Results: CD138– CD34– cells were found to have tumor stem cell characteristics. All the mice developed tumors in 40 days after injection of 1 × 106 CD138– CD34– tumor stem cells. Tumor growth in mice treated with PTX-NPs was significantly inhibited compared with the controls (P <  0.005, and the groups that received nanoparticles alone (P < 0.005 or paclitaxel alone (P < 0.05. In addition

  10. Preparation of C18-functionalized Fe3O4@SiO2 core-shell magnetic nanoparticles for extraction and determination of phthalic acid esters in Chinese herb preparations.

    Science.gov (United States)

    Guo, Bize; Ji, Shunli; Zhang, Feifang; Yang, Bingcheng; Gu, Jiangping; Liang, Xinmiao

    2014-11-01

    The extraction and determination of phthalic acid esters (PAEs) residue in Chinese herbal preparations (CHP) by C18-functionalized magnetic nanoparticles (C18-FS-MNP) has been firstly performed. It was synthesized through coating Fe3O4 nanoparticles with sodium silicate, followed by freeze-drying technique and then modified with C18 groups. C18-FS-MNPs prepared via freeze-drying technique were superior to those particles prepared via common vacuum drying method in terms of dispersion and extraction recovery. C18-FS-MNPs demonstrated obvious enrichment effect for four model PAEs and 478-627-fold enrichment factors were obtained. The limit of detection was <1.89ng/mL and relative standard deviation was ranging from 3.7 to 5.8%. It was successfully applied for determination of trace PAEs residue in CHP with good recoveries. Copyright © 2014 Elsevier B.V. All rights reserved.

  11. Aluminium hydroxide stabilised MnFe2O4 and Fe3O4 nanoparticles as dual-modality contrasts agent for MRI and PET imaging.

    Science.gov (United States)

    Cui, Xianjin; Belo, Salome; Krüger, Dirk; Yan, Yong; de Rosales, Rafael T M; Jauregui-Osoro, Maite; Ye, Haitao; Su, Shi; Mathe, Domokos; Kovács, Noémi; Horváth, Ildikó; Semjeni, Mariann; Sunassee, Kavitha; Szigeti, Krisztian; Green, Mark A; Blower, Philip J

    2014-07-01

    Magnetic nanoparticles (NPs) MnFe2O4 and Fe3O4 were stabilised by depositing an Al(OH)3 layer via a hydrolysis process. The particles displayed excellent colloidal stability in water and a high affinity to [(18)F]-fluoride and bisphosphonate groups. A high radiolabeling efficiency, 97% for (18)F-fluoride and 100% for (64)Cu-bisphosphonate conjugate, was achieved by simply incubating NPs with radioactivity solution at room temperature for 5 min. The properties of particles were strongly dependant on the thickness and hardness of the Al(OH)3 layer which could in turn be controlled by the hydrolysis method. The application of these Al(OH)3 coated magnetic NPs in molecular imaging has been further explored. The results demonstrated that these NPs are potential candidates as dual modal probes for MR and PET. In vivo PET imaging showed a slow release of (18)F from NPs, but no sign of efflux of (64)Cu.

  12. 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.

  13. Encapsulation of Fe 3O 4 magnetic nanoparticles with poly(methyl methacrylate) via surface functionalized thiol-lactam initiated radical polymerization

    Science.gov (United States)

    Bach, Long Giang; Islam, Md. Rafiqul; Kim, Jong Tae; Seo, SungYong; Lim, Kwon Taek

    2012-01-01

    Poly(methyl methacrylate) (PMMA) was grafted onto Fe3O4 magnetic nanoparticles (MNPs) by using a thiol-lactam initiated radical polymerization (TLIRP) via grafting from approach. The surface of the MNPs was treated with the (3-mercaptopropyl)trimethoxysilane coupling agent to give thiol functionalized MNPs (MNPs-SH). Subsequently, the polymerization of MMA performed in the presence of the MNPs-SH and butyrolactam efficiently afforded PMMA-g-MNPs. The grafting of PMMA on the surface of the MNPs was investigated by FT-IR, 1H NMR, TGA, XPS, and EDX analyses. The morphology of the core/shell type PMMA-g-MNPs was confirmed by HR-TEM. GPC analysis showed that the molecular weight of PMMA and monomer conversion increased with the reaction time. The amount of the grafted polymer on the surface of the MNPs was found to be ca. 82.5% as estimated from TGA analysis. The MNPs and PMMA-g-MNPs were subjected to magnetic property investigation by SQUID, and the PMMA-g-MNPs showed relatively high saturated magnetization (53.3 emu/g) without any remanence or coercivity, which made the nanocomposites easily separable from solid-liquid phases suggesting their superparamagnetic character. The magnetic nanocomposites had an exceptionally good dispersibility in organic solvents as demonstrated by UV-Vis spectroscopy as well as time-dependent digital photographic monitoring.

  14. Synthesis, Characterization, and Study of In Vitro Cytotoxicity of ZnO-Fe3O4 Magnetic Composite Nanoparticles in Human Breast Cancer Cell Line (MDA-MB-231) and Mouse Fibroblast (NIH 3T3).

    Science.gov (United States)

    Bisht, Gunjan; Rayamajhi, Sagar; Kc, Biplab; Paudel, Siddhi Nath; Karna, Deepak; Shrestha, Bhupal G

    2016-12-01

    Novel magnetic composite nanoparticles (MCPs) were successfully synthesized by ex situ conjugation of synthesized ZnO nanoparticles (ZnO NPs) and Fe3O4 NPs using trisodium citrate as linker with an aim to retain key properties of both NPs viz. inherent selectivity towards cancerous cell and superparamagnetic nature, respectively, on a single system. Successful characterization of synthesized nanoparticles was done by XRD, TEM, FTIR, and VSM analyses. VSM analysis showed similar magnetic profile of thus obtained MCPs as that of naked Fe3O4 NPs with reduction in saturation magnetization to 16.63 emu/g. Also, cell viability inferred from MTT assay showed that MCPs have no significant toxicity towards noncancerous NIH 3T3 cells but impart significant toxicity at similar concentration to breast cancer cell MDA-MB-231. The EC50 value of MCPs on MDA-MB-231 is less than that of naked ZnO NPs on MDA-MB-231, but its toxicity on NIH 3T3 was significantly reduced compared to ZnO NPs. Our hypothesis for this prominent difference in cytotoxicity imparted by MCPs is the synergy of selective cytotoxicity of ZnO nanoparticles via reactive oxygen species (ROS) and exhausting scavenging activity of cancerous cells, which further enhance the cytotoxicity of Fe3O4 NPs on cancer cells. This dramatic difference in cytotoxicity shown by the conjugation of magnetic Fe3O4 NPs with ZnO NPs should be further studied that might hold great promise for the development of selective and site-specific nanoparticles. Schematic representation of the conjugation, characterization and cytotoxicity analysis of Fe3O4-ZnO magnetic composite particles (MCPs).

  15. The fate of iron nanoparticles in environmental waters treated with nanoscale zero-valent iron, FeONPs and Fe3O4NPs.

    Science.gov (United States)

    Peeters, Kelly; Lespes, Gaëtane; Zuliani, Tea; Ščančar, Janez; Milačič, Radmila

    2016-05-01

    Among the different nanoparticles (NPs) that are used in the remediation of contaminated environmental waters, iron nanoparticles (FeNPs) are the most frequently applied. However, if these FeNPs remain in the waters after the treatment, they can cause a hazard to the environment. In this work the time dependent size distribution of iron particles was investigated in Milli-Q water, forest spring water and landfill leachate after a variety of FeNP treatments. The efficiency of the metal removal by the FeNPs was also examined. The concentrations of the metals in the aqueous samples were determined before and after the nano-remediation by inductively coupled plasma mass spectrometry (ICP-MS). The data revealed that the settling and removal of the FeNPs after the treatment of the waters was related to the sample characteristics and the ways of dispersing the NPs. When mixing was used for the dispersion, the nano zero-valent iron (nZVI), FeONPs and Fe3O4NPs settled quickly in the Milli-Q water, the forest spring water and the landfill leachate. Dispersion with tertramethylammonium hydroxide (TMAH) resulted in a slower settling of the iron aggregates. In the Milli-Q and forest spring waters treated with FeONPs and dispersed by TMAH, the nanosized iron remained in solution as long as 24 h after the treatment and could represent a potential threat in environmental waters with a low ionic strength. The removal of the metals strongly depended on the type of FeNPs, the chemical speciation of the elements and the sample matrix. If the FeNPs are contaminated by a particular metal, this contaminant could be, during the NPs treatment, released into the water that is being remediated.

  16. 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.

  17. Synthesis of Carboxyl-functionalized Silica Coated Fe3O4Magnetic Nanoparticles and Their Adsorption Ability of Cu2+%羧基化核壳磁性纳米Fe3O4吸附剂的制备及对Cu2+吸附性能

    Institute of Scientific and Technical Information of China (English)

    郑群雄; 刘煌; 徐小强; 杜美霞

    2012-01-01

    Carboxyl-functionalized Fe3O4 magnetic nanoparticles(CMNP) with core-shell structure were prepared by modifying silica coated Fe3O4 magentic nanoparticles( MNP) , which were successfully prepared by co-precipitation method, with 3-aminopropyltriethoxysilane( APTES) and Succinic anhydride. The morphology, structure, chemical composition and magnetic characteristics of the CMNP were characterized by transmission electron microscopy (TEM), X-ray diffraction (XRD), X-ray energy dispersive spectroscopy ( EDS), vibrating sample magnetometer ( VSM), thermal gravimetric analysis ( TGA ) and Fourier-transformed infrared spectroscopy (FTIR). Moreover, the adsorption properties of the CMNP for the removal of Cu2+ in aqueous solution were investigated and various factors affecting the absorption behavior of Cu2+ such as initial pH value, initial concentration of Cu2+ and contact time were studied. The TEM results show that the average partical size of CMNP is 15 nra. Magnetic measurement reveals it is nearly superparamagnetic with a saturation magnetization of 41. 84 A · M2/kg. Adsorption equilibrium was achieved rapidly in 10 min and adsorption data of CMNP fitted well with the Langmuir isotherm model with the maximum adsorption capacity of 43. 48 mg/g, the maximum uptake of Cu2+ was recorded at pH = 7.%在以共沉淀法制备的磁性纳米Fe3O4粒子(Magnetic nanoparticles,MNP)表面进行了化学修饰,制备了一种新型富含羧基功能团的核壳磁性纳米吸附剂(Carboxylic functionalized Fe3O4 magnetic nanoparticles,CMNP).利用透射电子显微镜(TEM)、X射线衍射仪(XRD)、X射线能量色散谱(EDS)、振动样品磁强计( VSM)、傅里叶变换红外光谱(FIIR)和热重分析仪(TGA)对CMNP的形貌、结构、化学组成和磁性能进行了表征,并考察了吸附剂对Cu2+的吸附性能,研究了溶液pH值、吸附时间和Cu2+初始浓度对吸附性能的影响.结果表明,羧基化核壳磁性纳米Fe3O4颗粒的平均粒径为15 nm,

  18. Removal of Hg(II) by poly(1-vinylimidazole)-grafted Fe3O4@SiO2 magnetic nanoparticles.

    Science.gov (United States)

    Shan, Chao; Ma, Zhiyao; Tong, Meiping; Ni, Jinren

    2015-02-01

    Fe3O4@SiO2 magnetic nanoparticles modified by grafting poly(1-vinylimidazole) oligomer (FSPV) was fabricated as a novel adsorbent to remove Hg(II) from water. Fourier transform infra-red spectroscopy confirmed the successful grafting of oligomer, and thermogravimetric analysis showed FSPV had a high grafting yield with organic content of 22.8%. Transmission electron microscopy image displayed that FSPV particles were polymer-coated spheres with size of 10-20 nm. With saturation magnetization of 44.7 emu/g, FSPV particles could be easily separated from water with a simple magnetic process in 5 min. The Hg(II) adsorption capacity of FSPV was found to be 346 mg/g at pH 7 and 25 °C in 10 mM NaCl. Moreover, the removal of Hg(II) by FSPV was not obviously affected by solution pH (from 4 to 10) or humic acid (up to 8 mg/L as TOC). The presence of seven common ions including Na(+), K(+), Ca(2+), Mg(2+), Cl(-), NO3(-), and SO4(2-) (up to 100 mM ionic strength) slightly increased the adsorption of Hg(II) by FSPV. X-ray photoelectron spectroscopy analysis revealed that the N atom of the imidazole ring was responsible for the bonding with Hg(II), whereas the bonding of Hg with N did not result in cleavage of Hg-Cl bond in HgCl2 and HgClOH. The regeneration of Hg(II)-loaded FSPV could be achieved with 0.5 M HCl rapidly in 10 min, and the removal of Hg(II) maintained above 94% in five consecutive adsorption-desorption cycles. Therefore, FSPV could serve as a promising adsorbent for Hg(II) removal from water.

  19. Sol-gel encapsulation of pullulanase in the presence of hybrid magnetic (Fe3O4-chitosan) nanoparticles improves thermal and operational stability.

    Science.gov (United States)

    Long, Jie; Li, Xingfei; Zhan, Xiaobei; Xu, Xueming; Tian, Yaoqi; Xie, Zhengjun; Jin, Zhengyu

    2017-02-27

    Pullulanase was sol-gel encapsulated in the presence of magnetic chitosan/Fe3O4 nanoparticles. The resulting immobilized pullulanase was characterized by scanning electron microscopy, vibrating sample magnetometry, Fourier transform infrared spectroscopy and thermogravimetric analysis. The results showed that the addition of pullulanase created a more regular surface on the sol-gel matrix and an enhanced magnetic response to an applied magnetic field. The maximal activity retention (83.9%) and specific activity (291.7 U/mg) of the immobilized pullulanase were observed under optimized conditions including an octyltriethoxysilane:tetraethoxysilane (OTES:TEOS) ratio of 1:2 and enzyme concentration of 0.484 mg/mL sol. The immobilized enzyme exhibited good thermal stability. When the temperature was above 60 °C, the immobilized pullulanase showed significantly higher activity than the free enzyme (p sol-gel encapsulation and co-immobilized by crosslinking-encapsulation retained 52 and 69% of their initial activity after 5 h at 62 °C, respectively, compared to 11% for the free enzyme. Moreover, the stability of the pullulanase was improved by crosslinking-encapsulation, as the enzyme retained more than 85 and 81% of its original activity after 5 and 6 consecutive reuses, respectively, compared to 80 and 72% of its original activity for simple sol-gel encapsulated enzymes. This indicated the leakage of enzyme molecules through the pores of the gel was substantially abated by cross-linking. Such immobilized pullulanase provides high stability and ease of enzyme recovery, characteristics that are advantageous for applications in the food industry that involve continuous starch processing.

  20. 肿瘤治疗用Fe3O4/P(NIPAAm-co-Am)磁性聚合物复合微球的磁热性能%Magnetocaloric effect of Fe3O4/P(NIPAAm-co-Am)composite microspheres for tumor treatment application

    Institute of Scientific and Technical Information of China (English)

    范少勇; 黄科棣; 唐清美; 黄志荣; 艾凡荣; 陈伟高

    2013-01-01

    Research on the magnetic thermo-sensitive composite microspheres for controlled release drug carrier was meaningful.Magnetocaloric effect was used to heat the Fe3O4/P (NIPAAm-co-Am)composite micro-spheres,and the heat generation abilities of the composited microspheres in alternation magnetic field (AMF) were investigated in the present work.Results show the resultant Fe3O4/P(NIPAAm-co-Am)composite mi-crospheres exhibite excellent superparamagnetic and high heating generation ability.The temperature of the composite microspheres was raised after exposed to AMF,which can stimulate the shrinks of P(NIPAAm-co-Am).Furthermore,the temperature raised after exposed to AMF can be adj usted by controlling the concentra-tion of composite microspheres,the magnetic intensity and the frequency of the AMF.%利用磁性纳米粒子在交变磁场作用下的磁热效应,来实现对 Fe3 O4/P(NIPAAm-co-Am)复合微球温度的控制,以达到肿瘤热疗与化疗联合治疗的目的。主要研究了交变磁场作用下复合微球的磁热性能的影响因素。研究结果表明,所制备的 Fe3 O4/P (NIPAAm-co-Am)复合微球具有很好的超顺磁性,且在交变磁场作用下具有很好的磁热效应,其磁热效应可以通过调节微球的浓度、交变磁场的磁场强度和频率等因素来调控,以适应不同应用场合需求。