Synthesis and characterization of core-shell Ag@Fe3O4 nanoparticles

A size-tunable core-shell nanoparticles is fabricated in which an Ag core is surrounded by a magnetic Fe₃O₄ shell. Quenching of the Ag surface plasmon is observed in the UV/Visible spectrum of Ag@Fe₃O₄. On the other hand, clear absorption peak appears on the mixture of pure Ag and Fe₃O₄ nanoparticles, implying that the Fe₃O₄ shell indeed changes the surface absorption. The TEM images reconfirmed the core-shell structure with the average core diameter of 10 nm and the width of 2 nm at room temperature. The nanoparticles are superparamagnetic at room temperature and may be suitable for biomedical application.