A General Route to Construct Diverse Multifunctional Fe₃O₄/Metal Hybrid Nanostructures

Multifunctional nanostructures : By using 3‐aminopropyltrimethoxysilane as a linker, Au nanoparticles (NPs), Au shells, flowerlike Au/Pt hybrid NPs, and Ag or Au/Ag core/shell NPs could be supported on the surface of superparamagnetic Fe 3 O 4 spheres to construct hybrid nanostructures that display near‐IR absorption, high catalytic activity towards an electron‐transfer reaction, or excellent surface‐enhanced Raman scattering activity. The picture shows SEM images of Fe 3 O 4 spheres coated with Au shells (top) and with Au/Pt hybrid NPs (bottom). magnified image We have developed a simple, efficient, economical, and general approach to construct diverse multifunctional Fe 3 O 4 /metal hybrid nanostructures displaying magnetization using 3‐aminopropyltrimethoxysilane (APTMS) as a linker. High‐density Au nanoparticles (NPs) could be supported on the surface of superparamagnetic Fe 3 O 4 spheres and used as seeds to construct Au shell‐coated magnetic spheres displaying near‐infrared (NIR) absorption, which may make them promising in biosensor and biomedicine applications. High‐density flowerlike Au/Pt hybrid NPs could be supported on the surface of Fe 3 O 4 spheres to construct multifunctional hybrid spheres with high catalytic activity towards the electron‐transfer reaction between potassium ferricyanide and sodium thiosulfate. High‐density Ag or Au/Ag core/shell NPs could also be supported on the surface of Fe 3 O 4 spheres and exhibited pronounced surface‐enhanced Raman scattering (SERS), which may possibly be used as an optical probe with magnetic function for application in high‐sensitivity bioassays.