Studies on colloidal stability of PVP-coated LSMO nanoparticles for magnetic fluid hyperthermia

Abstract

La0.7Sr0.3MnO3 (LSMO) nanoparticles with a size of ∼23 nm have been prepared by a combustion method and functionalized with polyvinylpyrrolidone (PVP) for their possible application in magnetic fluid hyperthermia (MFH). Uncoated and PVP-coated samples were characterized by X-ray diffraction, Fourier transform infrared spectroscopy, scanning electron microscopy, transmission electron microscopy, high resolution transmission electron microscopy and vibrating sample magnetometer studies. Magnetic measurements of both coated and uncoated particles reveal the superparamagnetic nature at room temperature. Colloidal stability has been measured in terms of zeta potential. The resulting PVP-coated particles form a stable suspension in phosphate buffer saline (PBS) and double distilled water (DDW) and possess a narrow hydrodynamic size distribution. The induction heating studies of these nanoparticles at different alternating magnetic fields (167.6, 251.4 and 335.2 Oe) were carried out by dispersing nanoparticles in DDW and PBS. These PVP-coated LSMO NPs exhibit a higher specific absorption rate in PBS than in DDW. The results suggest that combustion-synthesized LSMO nanoparticles coated with PVP can be used as potential heating agents in MFH.