Magnetic Core/Shell Fe 3 O 4 /Au and Fe 3 O 4 /Au/Ag Nanoparticles with Tunable Plasmonic Properties

Core/shell structured Fe3O4/Au and Fe3O4/Au/Ag nanoparticles are synthesized by depositing Au and Ag on the Fe3O4 nanoparticle surface in aqueous solution at room temperature. The control on shell thickness allows the tuning of plasmonic properties of the core/shell structure to be either red-shifted (to 560 nm) or blue-shifted (to 501 nm). Such magneto-optical nanoparticles should have great potentials for nanoparticle-based diagnostic and therapeutic applications.