Monodisperse sodium oleate coated magnetite high susceptibility nanoparticles for hyperthermia applications

We report a simple and low cost methodology to synthesize sodium oleate coated magnetite nanoparticles for hyperthermia applications. The system consists of oleate coated magnetite nanoparticles with large susceptibility (1065 emu/gT), induced by the dipolar inter-particle interaction, with a magnetic core diameter in the 6 nm-12 nm size range. In aqueous medium, the nanoparticles agglomerate to form a monodisperse system, exhibiting a mean hydrodynamic diameter of 60.6 nm±4.1 nm, with a low average polydispersity index of 0.128±0.003, as required for intravenous applications. The system exhibits promising efficiency for magnetic hyperthermia, with a specific absorption rate of 14 W/g at a low field amplitude of 15.9 kA/m and frequency of 62 kHz. In a 50 mg/mL density in 1 mL, the temperature rises to 42.5 °C in 1.9 min.