Facile synthesis of Ag@Fe 3 O 4 @C-Au core-shell microspheres for surface-enhanced Raman scattering

In this paper, a facile approach has been developed to synthesize the novel multifunctional Ag@Fe 3 O 4 @C-Au magnetic core-shell microspheres that display a highly efficient surface-enhanced Raman scattering (SERS) substrate with high stability and reproducibility. The morphology, size, chemical component, and magnetic property of as-prepared composite microspheres were characterized by scanning transmission electron microscopy (SEM), transmission electron microscopy (TEM), X-ray diffraction (XRD), thermogravimetric analysis (TGA), X-ray photoelectron spectra (XPS), and vibrating sample magnetomerter (VSM), respectively. The enhancement effect on the Raman active was investigated by using rhodamine-b (RdB) as a probe molecule. The result shows that the well-designed Ag@Fe 3 O 4 @C-Au core-shell microspheres have uniform sphere size and high magnetization, and the SERS signals of RdB on the Ag@Fe 3 O 4 @C-Au microspheres were much stronger than those on both Ag@Fe 3 O 4 and Fe 3 O 4 @C-Au microspheres.