Superparamagnetic nanorings of polystyrene/Fe3O4 composite were synthesized by miniemulsion polymerization. The nanoring structure was characterized by using transmission electron microscopy, scanning electron microscopy, and atomic force microscopy. The results of X-ray diffraction identified the magnetic constituent of as-synthesized composite nanorings as Fe3O4. The magnetization measurement...

To explore whether the magnetic nanoparticles of Fe3O4 (MNPs-Fe3O4) loaded with cisplatin can reverse the diaminedichloro platinum (DDP) resistance to multidrug resistance of ovarian carcinoma cells and to investigate its mechanisms. The SKOV3/DDP cells were divided into DDP treatment (DDP group), MNPs-Fe3O4 treatment (MNPs-Fe3O4 group), DDP + MNPs-Fe3O4 treatment (DDP + MNPs-Fe3O4 group), and ...

We descried a method to synthesize single crystalline Fe3O4 nanotubes by wet-etching the MgO inner cores of MgO/Fe3O4 core-shell nanowires. Homogeneous Fe3O4 nanotubes with controllable length, diameter, and wall thickness have been obtained. Resistivity of the Fe3O4 nanotubes was estimated to be approximately 4 x 10-2 Omega cm at room temperature. Magnetoresistance of approximately 1% was obse...

Magnetic iron oxide nanoparticles (Fe3O4 MNPs) are among the most useful metal nanoparticles for multiple applications across a broad spectrum in the biomedical field, including the diagnosis and treatment of cancer. In previous work, we synthesized and characterized Fe3O4 MNPs using a simple, rapid, safe, efficient, one-step green method involving reduction of ferric chloride solution using br...

We present measurements of the spin and orbital magnetic moments of Fe3O4 by using SQUID and magnetic circular dichroism in soft x-ray absorption. The measurements show that Fe3O4 has a noninteger spin moment, in contrast to its predicted half-metallic feature. Fe3O4 also exhibits a large unquenched orbital moment. Calculations using the local density approximation including the Hubbard U metho...

We report a facile intracellular manipulation of fluorescent magnetic Fe3O4-CdSe nanoparticles using magnetic force. The growth of CdSe quantum dots on Fe3O4 nanoparticles produces Fe3O4-CdSe nanoparticles with two distinct properties, fluorescence and superparamagnetism. After nonspecific surface modification using glutathione (GSH), the hydrophilic Fe3O4-CdSe@GSH nanoparticles can be easily u...

A magnetic chitosan-polypyrrole-magnetite (Cs-PPy-Fe3O4) nanocomposite is prepared in a simple one-step method via in situ chemical polymerization of pyrrole using anhydrous FeCl3 as an oxidant in the presence of Cs. Magnetic Fe3O4 nanoparticles of size in the range of 10-20 nm are successfully introduced into the Cs-PPy matrix. Adsorption of an anionic dye (acid green 25, AG) from aqueous solu...

Magnetic nanoparticles with attractive optical properties have been proposed for applications in such areas as separation and magnetic resonance imaging. In this paper, a simple and novel fluorescent sensor of Zn2+ was designed with 3,5-di-tert-butyl-2-hydroxybenzaldehyde [DTH] covalently grafted onto the surface of magnetic core/shell Fe3O4@SiO2 nanoparticles [NPs] (DTH-Fe3O4@SiO2 NPs) using t...

The evaluation of the toxicity of magnetic nanoparticles (MNPs) has attracted much attention in recent years. The current study aimed to investigate the cytotoxic effects of Fe3O4, oleic acid-coated Fe3O4 (OA-Fe3O4), and carbon-coated Fe (C-Fe) nanoparticles on human hepatoma BEL-7402 cells and the mechanisms. WST-1 assay demonstrated that the cytotoxicity of three types of MNPs was in a dose-d...

The Verwey transition in Fe3O4 is the first metal-insulator transition caused by charge ordering. However, the physical mechanism and influence factors of Verwey transition are still debated. Herewith, the strain effects on the electronic structure of low-temperature phase (LTP) Fe3O4 with P2/c and Cc symmetries are investigated by first-principles calculations. LTP Fe3O4 with each space group ...