Physicochemical characterization of Fe3O4/SiO2/Au multilayer nanostructure

► The purpose of the research was to synthesize and characterize Fe3O4/SiO2/Au NPs. ► Uncoated MNPs showed an Ms range of 80-100 emu g−1 for particles between 35-96 nm. ► The magnetic NPs were modified with a thin layer of silica using Stober method. ► Small gold colloids (1-3 nm) were covered the amino functionalized particle surface. ► An absorption peak of 550 nm was obtained for a gold thickness of about 35 nm.