Development of gold-coated magnetic nanoparticles as a theranostic agent for magnetic hyperthermia and CT imaging applications

In this study, we aim to develop gold-coated Fe3O4 nanoparticles (Fe3O4@Au NPs) as theranostic agents for magnetic hyperthermia and CT imaging applications. The Fe3O4 NPs were synthesized via thermal decomposition method, and the gold was then deposited onto the surface of Fe3O4 NPs by reducing gold acetate at 190 °C. The average sizes of Fe3O4 and Fe3O4@Au NPs were 5.2 nm and 6.1 nm, respectively, which are effectively removed by the kidneys. The magnetization of Fe3O4@Au NPs (9.7 emu/g-Fe3O4) at 300 K was much smaller than that of Fe3O4 NPs (52.4 emu/g-Fe3O4). The heating efficiency of Fe3O4@Au NPs in water was sufficient to treat the tumor at 43-45 °C, and their high CT value of 851 HU was obtained. The synthesized ultrasmall Fe3O4@Au NPs showed great promise as a potential theranostic agent for magnetic hyperthermia and CT imaging applications.