Effects of Mn doping on surface enhanced Raman scattering properties of TiO2 nanoparticles

TiO₂ and Mn-doped TiO₂ (1%, 3% and 5%) 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%) samples. On the 3% Mn doped TiO₂ substrate, 4-MBA molecules exhibit a higher SERS intensity by a factor of six as 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 up a new dimension for the family of SERS substrates.