A Facile and Green Synthetic Route for Preparation of Heterostructure Fe3O4@Au Nanocomposites

Magnetic nanoparticles offer many exciting opportunities in biology and biomedicine, such as magnetic resonance imaging, magnetic hyperthermia therapy, biomedical diagnosis. The synthesis of multifunctional magnetic nanocomposites that possess water-solubility, magnetic properties and optical stability by a green method at room temperature in aqueous phase is still an unmet need. Here, we developed a simple and green method for preparing Fe 3 O 4 @Au integrated the super-paramagnetic and optical properties by seed-mediated growth at mild condition in aqueous phase. The amphiphilic, non-ionic and nontoxic polymer poly(vinylpyrrolidone) (PVP) was used as a coupling agent for synthesis of Fe 3 O 4 @Au nanocomposites, which avoided the direct connection of Au and Fe 3 O 4 , and improved the saturation magnetization values of Fe 3 O 4 @Au to 40 emu/g at room temperature. We anticipate that the multifunctional Fe 3 O 4 @Au nanocomposites with high magnetic and good optical properties will provide a platform for potential diagnostic and therapeutic biomedical applications.