Photocatalytic preparation of Ag/TiO2 films and their localized surface plasmon resonance sensing properties

Photocatalytic deposition of Ag nanoparticles from AgNO3 aqueous solution onto TiO2 films (Ag/TiO2 films) was carried out by using ultraviolet light irradiation at room temperature. The Ag/TiO2 films were characterized by XRD, XPS, and SEM. The mean diameter of Ag nanoparticles on the film was estimated to be 113 run. In the optical absorption spectra of the Ag/TiO2 film, the localized surface plasmon resonance (LSPR) peak of Ag nanoparticles was observed around 390 nm. A linear relation was clearly observed between the LSPR peak wavelength and the refractive index of the surrounding media, such as alcohols, D-glucose and urea aqueous solutions, in the range of 1.0003-1.4394. The Ag/TiO2 films were easy to prepare and had a reproducible SPR sensing performance.