TiO compact layer induced charge transfer enhancement in a three-dimensional TiO-Ag array SERS substrate for quantitative and multiplex analysis.

A highly sensitive and uniform surface-enhanced Raman scattering (SERS) substrate is the guarantee for reliable quantitative analysis. Herein, a three-dimensional TiO-Ag SERS substrate was prepared by growing a TiO nanorods (NRs) array on a TiO compact layer (c-TiO), followed by modification with Ag nanoparticles (AgNPs). The synergy between the c-TiO, semiconductor TiO NRs and the plasmonic AgNPs collaboratively endowed it with high sensitivity, in which c-TiO effectively blocked the recombination of electrons and holes, and the charge transfer enhancement contributed 10-fold improvement over that without the c-TiO substrate.