A Simple Method To Construct Bifunctional Fe3O4/Au Hybrid Nanostructures and Tune Their Optical Properties in the Near-Infrared Region

In this paper, we have developed a simple, facile, and efficient approach to synthesize bifunctional Fe 3 O 4 /Au hybrid nanostructure using l -cysteine as a linker. The morphology, composition, crystallinity, and magnetism of the as-prepared nanocomposites were characterized by transmission electron microscopy (TEM), scanning electron microscopy (SEM), energy-dispersive X-ray (EDX), powder X-ray diffraction (XRD), and superconducting quantum interference device (SQUID). The results indicated that the spherical composite particles showed a monodispersity and supermagnetism. The surface of the composite spheres contained plentiful Au nanoparticles (NPs) smaller than 10 nm. And the absorption peak of the composite spheres could be conveniently tuned over a broad spectral range spanning from the visible to the near-infrared (NIR) by simply controlling the diameter of Fe 3 O 4 . This novel bifunctional hybrid nanostructure will open up an exciting opportunity in biomedical applications.