Studies of magnetite nanoparticles synthesized by thermal decomposition of iron (III) acetylacetonate in tri(ethylene glycol)

In this paper, water-soluble magnetite nanoparticles have been directly synthesized by thermal decomposition of iron(III) acetylacetonate, Fe(acac) 3 in tri(ethyleneglycol). Size and morphology of the nanoparticles are determined by transmission electron microscopy(TEM) and dynamic light scattering (DLS) measurements while the crystal structure is identified using X-ray diffraction(XRD). Surface charge and surface coating of the nanoparticles are recognized using Fourier transform infrared spectroscopy(FTIR), X-ray photoelectron spectra(XPS) and zeta potential measurements. Magnetic properties are determined using vibrating sample magnetometer(VSM) and superconducting quantum interference device(SQUID) measurements. The results show that as-prepared magnetite nanoparticles are relatively monodisperse, single crystalline and superparamagnetic in nature with the blocking temperature at around 100 K. The magnetite nanoparticles are found to be highly soluble in water due to steric and electrostatic interactions between the particles arising by the surface adsorbed tri(ethyleneglycol) molecules and associated positive charges, respectively. Cytotoxicity studies on human cervical(SiHa), mouse melanoma(B16F10) and mouse primary fibroblast cells demonstrate that up to a dose of 80 mu g/ml, the magnetic nanoparticles are nontoxic to the cells. Specific absorption rate (SAR) value has been calculated to be 885 and 539 W/gm for samples with their on concentration of 1 and 0.5 mg/ml, respectively. The high SAR value upon exposure to 20 MHz radio frequency signifies the applicability of as-prepared magnetite nanoparticles for a feasible magnetic hyperthermia treatment. (C) 2009 Elsevier B. V. All rights reserved.