SONOCHEMICAL PREPARATION OF GOLD/IRON OXIDE COMPOSITE MAGNETIC NANOPARTICLES AND SELECTIVE MAGNETIC SEPARATION OF BIOMOLECULES

2006 ◽  
Vol 05 (02n03) ◽  
pp. 359-363 ◽  
Author(s):  
YOSHITERU MIZUKOSHI ◽  
SATOSHI SEINO ◽  
KENJI OKITSU ◽  
TAKUYA KINOSHITA ◽  
TAKASHI NAKAGAWA ◽  
...  
Keyword(s):  
Magnetic Field ◽  
Amino Acids ◽  
External Magnetic Field ◽  
Au Nanoparticles ◽  
Average Diameter ◽  
Composite Nanoparticles ◽  
Magnetic Separations ◽  
Magnetic Carriers ◽  
Standard Solution ◽  
Sulfur Containing

We have successfully prepared Au nanoparticles by the sonochemically reducing Au(III) ions and immobilized them on the surface of magnetic γ- Fe 2 O 3 nanoparticles. Au particles with average diameter of about 10 nm were homogeneously dispersed on the surface of γ- Fe 2 O 3 (average diameter : 26 nm) without aggregation. Au nanoparticles are known to selectively adsorb the molecules having sulfur. Aiming at the uses for magnetic carriers of specific biomolecules, we employed prepared composite nanoparticles for selective separation of biomolecules and estimated their adsorption properties. The composite nanoparticles exhibited a high affinity with glutathione, a tripeptide with mercapto group, so that separation and manipulation of glutathione in aqueous solutions could be performed by applying an external magnetic field. Magnetic separations of amino acids were also investigated. Composite nanoparticles were mixed with amino acid standard solution containing 17 kinds of amino acids and their magnetic separations were carried out by applying an external magnetic field. It was found that adsorption amounts of methionine and cystine, containing internal sulfur were larger than other amino acids. The adsorbed amounts of sulfur containing amino acids increased with relative amount of Au in the composite nanoparticles.

Preparation and Characterization of Mno.5Zno.5Fe2O4 @Au Composite Nanoparticles and its Anti-Tumor Effect on Glioma Cells

2011 ◽  
Vol 138-139 ◽  
pp. 907-913
Author(s):  
Yun Tao Li ◽  
Jing Liu ◽  
Li Wang ◽  
Jia Zhang ◽  
Zi Yu Wang ◽  
...  
Keyword(s):  
Magnetic Field ◽  
Electron Microscopy ◽  
Au Nanoparticles ◽  
Glioma Cells ◽  
Trisodium Citrate ◽  
Average Diameter ◽  
Composite Nanoparticles ◽  
Au Nanoparticle ◽  
Core Shell

To explore the preparation method and characters of a new gold nanoshells on maganese-zinc ferrite (Mno.5Zno.5Fe2O4@Au) composite nanoparticles. Mno.5Zno.5Fe2O4@Au nanoparticles with core/shell structure were synthesized by reduction of Au3+ with trisodium citrate in the presence of Mno.5Zno.5Fe2O4 magnetic nanoparticles (MZF-NPs) prepared by improved co-preciption with the character of superparamagnetism and detected by transmission electron microscopy (TEM), scanning electron microscopy (SEM), x-ray diffraction (XRD), energy dispersive spectrometry (EDS) and Marven laser particle size analyzer.Thermodynamic test was used to observe temperature change of various doses of Mno.5Zno.5Fe2O4@Au nanoparticles. The cytotoxicity of the Mno.5Zno.5Fe2O4@Au composite nanoparticles in vitro was tested by the MTT assay. The therapeutic effect of Mno.5Zno.5Fe2O4@Au composite nanoparticles combined with magnetic fluid hyperthermia (MFH) on human glioma cells were evaluated in vitro by an MTT assay.The results indicated that the Mno.5Zno.5Fe2O4@Au composite nanoparticles were prepared successfully. The core/shell particles were spherical with exact average diameter of them was 66.9nm.EDS showed each Mno.5Zno.5Fe2O4@Au nanoparticle contained Mn, Zn, Fe, O and Au elements, and this proved Au had successfully attached to Mn0.5Zn0.5Fe2O4.The result of thermodynamic test showed that Mno.5Zno.5Fe2O4@Au composite nanoparticles could serve as a heating source under alternating magnetic field (AMF) exposure leading to reach their steady temperature (40-45°C). Moreover, Mno.5Zno.5Fe2O4@Au composite nanoparticles didn’t show cytotoxicity in vitro. The therapeutic result reveals that Mno.5Zno.5Fe2O4@Au composite nanoparticles can significantly inhibit the growth of glioma cells.The conclusion was that the self-prepared Mno.5Zno.5Fe2O4@Au composite nanoparticles had strong magnetic responsiveness and good power absorption capabilities in the high frequency AMF,then they could suggested to be useful for glioma hyperthemia. Mno.5Zno.5Fe2O4 @Au composite nanoparticles can not only be directed to tumor region in a given magnetic field more exactly but also produce marked thermotherapy.

scholarly journals Synthesis of cobalt nanowires in aqueous solution under an external magnetic field

2016 ◽  
Vol 7 ◽  
pp. 990-994 ◽  
Author(s):  
Xiaoyu Li ◽  
Lijuan Sun ◽  
Hu Wang ◽  
Kenan Xie ◽  
Qin Long ◽  
...  
Keyword(s):  
Magnetic Field ◽  
Aqueous Solution ◽  
External Magnetic Field ◽  
Room Temperature ◽  
Magnetic Measurements ◽  
Chemical Reduction ◽  
Average Diameter ◽  
Firm Structure ◽  
Cobalt Nanowires ◽  
First Time

In contrast to the majority of related experiments, which are carried out in organic solvents at high temperatures and pressures, cobalt nanowires were synthesized by chemical reduction in aqueous solution with the assistance of polyvinylpyrrolidone (PVP) as surfactant under moderate conditions for the first time, while an external magnetic field of 40 mT was applied. Uniform linear cobalt nanowires with relatively smooth surfaces and firm structure were obtained and possessed an average diameter of about 100 nm with a coating layer of PVP. By comparison, the external magnetic field and PVP were proven to have a crucial influence on the morphology and the size of the synthesized cobalt nanowires. The prepared cobalt nanowires are crystalline and mainly consist of cobalt as well as a small amount of platinum. Magnetic measurements showed that the resultant cobalt nanowires were ferromagnetic at room temperature. The saturation magnetization (M s) and the coercivity (H c) were 112.00 emu/g and 352.87 Oe, respectively.

Radiochemical Synthesis of Au/Iron-oxide Composite Nanoparticles Using PEG

2007 ◽  
Vol 1064 ◽  
Author(s):  
Satoshi Seino ◽  
Takuya Kinoshita ◽  
Juinichi Iida ◽  
Yujin Shibata ◽  
Takashi Nakagawa ◽  
...  
Keyword(s):  
Aqueous Solution ◽  
Iron Oxide ◽  
Average Diameter ◽  
Composite Nanoparticles ◽  
Polyethylene Glycols ◽  
Oxide Nanoparticles ◽  
Gold Particles ◽  
Adsorbed Sulfur ◽  
Sulfur Containing ◽  
Radiochemical Synthesis

ABSTRACTComposite nanoparticles consisting of gold and iron-oxide were radiochemically synthesized in aqueous solution systems by using polyethylene glycols. The gold particles with average diameter of 3 nm were firmly immobilized on the surface of the support iron-oxide nanoparticles. The composite nanoparticles specifically adsorbed sulfur-containing amino acids by a Au-S bonding.

Selective magnetic separation of sulfur-containing amino acids by sonochemically prepared Au/γ-Fe2O3 composite nanoparticles

2006 ◽  
Vol 54 (4) ◽  
pp. 609-613 ◽  
Author(s):  
Yoshiteru Mizukoshi ◽  
Satoshi Seino ◽  
Takuya Kinoshita ◽  
Takashi Nakagawa ◽  
Takao A. Yamamoto ◽  
...  
Keyword(s):  
Amino Acids ◽  
Magnetic Separation ◽  
Composite Nanoparticles ◽  
Sulfur Containing

scholarly journals MAGNETICALLY RECOVERABLE POLYMER CATALYST FOR CELLULOSE HYDROGENOLYSIS

2020 ◽  
Vol 63 (2) ◽  
pp. 59-63
Author(s):  
Oleg V. Manaenkov ◽  
Olga V. Kislitsa ◽  
Ekaterina A. Ratkevich ◽  
Mikhail G. Sulman
Keyword(s):  
Magnetic Field ◽  
External Magnetic Field ◽  
Hydrothermal Reaction ◽  
Biomass Conversion ◽  
Active Phase ◽  
Average Diameter ◽  
High Specific Surface Area ◽  
Reaction Mass ◽  
Recoverable Catalyst ◽  
Magnetically Recoverable Catalyst

A new type of Ru-containing magnetically recoverable catalyst based on a polymer matrix of hypercrosslinked polystyrene (HPS) for the reaction of the hydrogenolysis of microcrystalline cellulose to ethylene and propylene glycol (EG and PG) is proposed. The catalyst is synthesized sequentially in two stages. At the first stage, by means of thermal decomposition of iron (III) salts in the presence of polyols, magnetite particles (Fe3O4) are formed in the pores of the HPS. At the second stage, Ru-containing nanoparticles of the active phase of the catalyst are synthesized on the surface of Fe3O4/HPS. Samples of the original HPS, Fe3O4/HPS and Ru-Fe3O4/HPS were characterized using various physicochemical methods. In particular, it was shown that the synthesized samples of catalysts have a high specific surface area (450 - 750 m2/g, depending on the magnetite content), retain the micro-mesoporous nature of the original polymer, and have a high saturation magnetization (4.0 ± 0.5 emu /g), which makes them easy to separate from the reaction mass by an external magnetic field. According to the results of transmission electron microscopy (TEM), the average diameter of the nanoparticles of the active phase Ru was 2.0 ± 0.5 nm. The hydrogenolysis of cellulose to glycols was carried out under the following conditions: 255 °C; 60 bar H2; 55 min; 0.3 g of cellulose; 0.07 g of catalyst 3% Ru-Fe3O4/HPS; 30 ml of H2O; 0.07 g of Ca(OH)2. Under these conditions, the selectivities for EG and PG were 22.6 % and 20.0 %, respectively. The degree of cellulose conversion reaches 100 %. The catalyst showed good stability under hydrothermal reaction conditions, is easily separated from the reaction mass by an external magnetic field, and can be used in the processes of cellulose-containing biomass conversion.

Multimodal Hybrid FePt/SiO2/Au Nanoparticles for Nanomedical Applications: Combining Photothermal Stimulation and Manipulation With an External Magnetic Field

2015 ◽  
Vol 119 (28) ◽  
pp. 16374-16382 ◽  
Author(s):  
Nina Kostevšek ◽  
Kristina Žužek Rožman ◽  
Muhammad Shahid Arshad ◽  
Matjaž Spreitzer ◽  
Spomenka Kobe ◽  
...  
Keyword(s):  
Magnetic Field ◽  
External Magnetic Field ◽  
Au Nanoparticles

Complex formation processes at the surface of Cu–O composite nanoparticles with and without external magnetic field

2007 ◽  
Vol 434-435 ◽  
pp. 646-649 ◽  
Author(s):  
Shizuka Kitashima ◽  
Atsushi Kuroda ◽  
Katsumasa Hirose ◽  
Mamoru Senna ◽  
Anatoly Ye. Yermakov ◽  
...  
Keyword(s):  
Magnetic Field ◽  
External Magnetic Field ◽  
Complex Formation ◽  
Composite Nanoparticles ◽  
Formation Processes

Methionine-Specific Staining of Collagen

1982 ◽  
Vol 40 ◽  
pp. 294-295
Author(s):  
E.M. Kuhn ◽  
K.D. Marenus ◽  
M. Beer
Keyword(s):  
Amino Acids ◽  
Collagen Fibers ◽  
Type Iii Collagen ◽  
Type I ◽  
Electron Microscopic ◽  
Good Correspondence ◽  
Specific Staining ◽  
Type Iii ◽  
Different Types ◽  
Sulfur Containing

Fibers composed of different types of collagen cannot be differentiated by conventional electron microscopic stains. We are developing staining procedures aimed at identifying collagen fibers of different types.Pt(Gly-L-Met)Cl binds specifically to sulfur-containing amino acids. Different collagens have methionine (met) residues at somewhat different positions. A good correspondence has been reported between known met positions and Pt(GLM) bands in rat Type I SLS (collagen aggregates in which molecules lie adjacent to each other in exact register). We have confirmed this relationship in Type III collagen SLS (Fig. 1).

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