Effect of a Ag-rGO structure on the SERS activity of PEDOT:PSS films.

π-Conjugated organic semiconductors with tunable electronic structures are new prospective active substrate materials for surface-enhanced Raman scattering (SERS). However, observing higher SERS activity when using organic semiconductors as substrates could be difficult because there is no plasmonic effect of hot electrons. Here, we designed a Ag-reduced graphene oxide (rGO) structure, introduced it into a poly(3,4-ethylenedioxythiophene)-poly(styrene sulfonate) (PEDOT:PSS) solution, and spin-coated the solution to obtain a Ag-rGO/PEDOT:PSS (ARPP) film. Our analyses demonstrate that the introduction of this Ag-rGO structure can not only enhance the electromagnetic field effect based on plasmon resonance but also improve the interaction between the target molecule and the substrate in the ARPP film. This innovative approach not only improves the SERS activity of π-conjugated organic polymers but also provides novel ideas for the preparation of other organic semiconductor-based SERS substrates.