▎ 摘　　要

Layer-by-layer photocatalyst films made of TiO2 nanoparticles (TiO2NP) assembled with both poly(sodium 4-styrenesulfonate) (PSS) and graphene oxide (GO) are used for the photodeposition of plasmonic Ag nanoparticles (AgNPs) and subsequently used in surface-enhanced Raman scattering (SERS). Both photocatalyst films, TiO2NP/PSS and TiO2NP/GO, are capable of driving the formation of AgNP when they are wetted with a drop of AgNO3 diluted solution and submitted to UV irradiation (254 nm). The photodeposition of AgNP, as monitored by UV-vis spectroscopy, follows a first-order kinetics process in both films and is slightly faster in the TiO2NP/PSS. In addition, scanning electron microscopy reveals that in the TiO2NP/PSS film, the photodeposited AgNPs are larger and isolated, whereas in the TiO2NP/GO film, they are smaller and highly interconnected. The SERS activity of the substrates is evaluated with rhodamine B. When samples are excited in resonance with rhodamine B absorption (514 nm), GO-based substrates provide the largest enhancement because GO is able to quench the rhodamine B fluorescence, something that PSS is unable to do. Out of this condition (633 nm), the plasmonic effect of AgNP alone prevails regardless of the presence of GO.