Synthesis of PVP capped superparamagnetic iron oxide (Fe3O4) nanoparticles in the inert atmosphere - An ideal candidate for hyperthermia

The Fe3O4 magnetite nanoparticles are the most promising materials in the medical applications because of their biocompatibility, stability and ease in synthesis. In the present study PVP capped iron oxide (Fe3O4) nanoparticles with a size range of 5-9nm were synthesised by the chemical co-precipitation method in an inert environment created by nitrogen gas flow. The PVP coating serves as the stabiliser and controls the crystal growth thereby the particle size. The diameter range of synthesised nanoparticles is preferred in the medical applications such as drug delivery system, MRI contrast agent and hyperthermia is in vicinity of 10nm. The Fe3O4 magnetic nanoparticles were prepared by the aqueous co-precipitation of FeCl3·6H2O and FeC12·4H2O with addition of sodium hydroxide and PVP at room temperature. The nanoparticles of different diameters were obtained by varying the concentration of the precursors and keeping the other experimental parameters same. The formation of magnetite is confirmed by X-ray diffraction (XRD) and energy dispersive spectroscopy (EDS). The particle size and the morphology are characterized by scanning electron microscopy (SEM) and XRD. The hysteresis loop and the saturation magnetisation were measured by vibrating sample magnetometer (VSM). The results revealed that the magnetic nanoparticles are spherical in shape and with narrow size distribution with high magnetic saturation. With the increase in the concentration of precursors not only the diameter but also the crystallinity and saturation magnetisation increases. The synthesised nanoparticles are ideal candidate for the hyperthermia owing to the size, superparamagnetic nature and saturation magnetisation.