Superparamagnetic Fe@Au Core/shell nanoparticles and their feasibility for magnetic hyperthermia*

Superparamagnetic Fe@Au core/shell nanoparticles have been synthesized at ambient condition at different ratios of Fe:Au precursors using one-step wet chemistry method and functinoalized with tween. SEM, TEM, and XRD reveal spherical FCC Fe core nanoparticles coated with Au shells. The particles sizes average 61, 71, 83 nm at Fe:Au precursor’s ratio of 1:1, 2:1, 3:2 respectively. VSM reveals superparamagnetic behavior at 300 K. The saturation magnetization (M_S) of the samples amounts 79, 165, and 89 emu/g for 61, 71, and 83 nm respectively. Feasibility for hyperthermia treatment of cancer have been tested under applied magnetic fields and frequencies, heating power known as specific absorption rate (SAR) has been recorded. SAR dependence of magnetic field and frequency yields 35, 50, 25 W/g at therapeutic range of 400 Oe and 304 kHz for samples with M_S of 79, 165, and 89 emu/g respectively. The samples show feasibility for future in vitro/in vivo studies for tumor cells.