Facile method for decorations of Au nanoparticles on TiO2 nanorod arrays toward high-performance recyclable SERS substrates

High-performance recyclable SERS substrates with well-ordered hybrid nanostructure gold nanoparticles (Au NPs) decorated on titanium dioxide nanorods (TiO2 NRs) were successfully prepared by combining two methods. The TiO2 NRs were fabricated by electron-beam evaporation with glancing-angle deposition (GLAD) technique, then the Au NPs were decorated onto the TiO2 NRs surfaces by deposition-precipitation (DP). The physical structures of the obtained hybrid nanostructures were characterized by field emission scanning electron microscope (FE-SEM), high resolution transmission electron microscope (TEM), and grazing incident angle X-ray diffraction (GIXRD). The results indicated that size and density of Au NPs on TiO2 NRs were controlled by HAuCl4 concentration for optimization of the SERS performance whose the detection of MB molecules was achieved at an enhancement factor of 6.5x10(7) with 9.76%-RSD at 1626 cm(-1). More significantly, the optimized hybrid nanostructure SERS substrates exhibit excellent recyclability. These hybrid nanostructure SERS substrates were therefore promising towards detection of TNT for homeland security applications, as well as an on-site SERS platform.