One-pot synthesis of iron core-iron oxide shell nanoparticles with potential for magnetic imaging

Iron based nanoparticles have shown promise in biomedical applications by possessing diagnostic and therapeutic capabilities. Currently, superparamagnetic iron oxide nanoparticles (SPIONs) are the standard magnetic materials used for magnetic based imaging and hyperthermia therapeutics due to their good magnetic properties, biocompatibility, and stability. However, further improvement of iron-based nanoparticles for such applications can be achieved by creating nanoparticles that possess a pure iron core. Therefore, this study investigates a one-pot synthesis of superparamagnetic iron core-shell nanoparticles using a thermal decomposition of iron pentacarbonyl. Reaction time and surfactant quantities were modified to investigate possible size, shape, and dispersion variations. Characterizations included transmission electron microscopy, x-ray diffraction, Mossbauer spectroscopy, vibrating sample magnetometry, zeta potential, and cytotoxicity studies. From this method, core-shell, monodispersed nanoparticles averaging 14 nm in size were produced and displayed good colloidal stability and high magnetic saturation up to 130 emu/g. Iron nanoparticles were coated with 1,2- distearoyl-sn-glycero-3-phosphoethanolamine-N-[methoxy- (polyethylene glycol)-2000] (ammonium salt) (DSPE-mPEG) polymer to increase biocompatibility and showed low cytotoxicity. The nanoparticles reported display high potential for magnetic imaging and magnetic hyperthermia applications.