A New SERS Substrate Based on TiO<sub>2</sub> Nanorods Thin Film Assembled Gold Nanoparticles

Abstract

Surface enhanced Raman scattering (SERS) has been proved to be a highly sensitive method to detect organic molecules at very low concentrations. In recent years, many researchers have reported that 1-dimension semiconductor nanomaterials assembled noble metal nanoparticles can get a strong SERS effect. In this paper, we succeeded to synthesize TiO2 nanorod thin films on fluorine-doped tin oxide (FTO) glass with hydrothermal synthesis which were able to be used as SERS substrates. Gold nanoparticles were assembled to TiO2 nanorod thin films using the physical sputtering method and the citrate reduction method, respectively. The field emission scanning electron microscope (FESEM) images show that the later method could achieve the more desirable and uniform distribution of gold nanoparticles. Rhodamine 6G (R6G) was chosen as the probe molecule to study the SERS performance of our novel SERS substrates. Raman scattering measurement proved that the substrates were able to enhance Raman signals by several orders of magnitude and could be applied to biochemical detection. The whole fabrication process was facile and cost-effective, and the SERS activity and reproducibility of the substrates were pretty good.