In the current project, TiO2 and Mn-doped TiO2 (1 percent, 3 percent, and 5 percent) nanoparticles (NPs) were synthesized by a sol-hydrothermal method for surface-enhanced Raman spectroscopy study.
When using the 4-mercaptobenzoic acid (4-MBA) as the probing molecule, optimum SERS signals were observed on the Mn–TiO2 (3 percent) samples. On the 3 percent Mn doped TiO2 substrate, 4-MBA molecules exhibited a higher SERS intensity by a factor of six compared with the native enhancement of 4-MBA adsorbed on pure TiO2 NPs. The possible mechanism for the phenomena is also discussed. This study opens a new dimension for the family of SERS substrates. (publisher abstract modified)