Seed-mediated synthesis of iron oxide and gold/iron oxide nanoparticles.

In this study, we prepared magnetic iron oxide and gold/iron oxide nanoparticles (NPs) and characterized their morphologies and properties by XRD, TEM, EDX, VSM and UV-vis measurements. The magnetite iron oxide NPs of 10 nm were synthesized by coprecipitation of Fe2+ and Fe+3 in the solution of NH4OH and then they were used as seed particles for the subsequent growth to prepare the magnetite NPs of different particle sizes and also to prepare gold/iron oxide composite NPs. All those magnetite NPs are superparamagnetic and the gold/iron oxide composite NPs combine the optical and magnetic properties, which are contributed by gold and iron oxide components, respectively.