Electrically tunable SERS based on plasmonic gold nanorod-graphene/ion-gel hybrid structure with a low voltage

Actively controlling the performance of surface-enhanced Raman scattering (SERS) holds great promise in enabling novel applications of this technique. As a popular two-dimensional material, graphene shows intriguing tunable properties and thus has become a promising material in many potential active device applications. Here we proposed and experimentally demonstrated low-voltage electrically tunable SERS by using a plasmonic gold nanorod-graphene/ion-gel hybrid structure. The SERS signals of molecules adsorbed on such a structure were found to be continuously tunable through an external small bias voltage. As such a tuning process is highly related with the charge transfer between the adsorbed molecules and graphene, the proposed design is also helpful in understanding the charge transfer-based enhancement mechanism of SERS.