Dual SERS Enhancement Using Silver Nanoshells and Graphene Quantum Dots

Recently, advanced Raman enhancement platforms using plasmonic nanoparticles (NPs) and non-plasmonic materials such as graphene or graphene quantum dots (GQDs) simultaneously have been reported, named ‘dual enhancement’ platforms. Compared to plasmonic substrates generally used, the dual enhancement platform has several advantages from advanced charge transfer-induced chemical mechanism enhancement (CM) between the molecules and graphene and attracting the analyte molecules even with weak affinity to plasmonic NP surfaces. In this study, novel design of dual SERS substrate is proposed based on bumpy Ag nanoshells (Ag NSs) and two type of GQDs with different edge structures, zigzag and armchair form. The fabricated SERS substrates were characterized by SEM, EDS, AFM and Raman spectroscopic analysis. Our dual SERS substrate exhibits enhanced signal compared to Ag NSs substrates. By controlling edge of GQDs, electronic structure of GQDs was tuned, leading to different CM effect for Rhodamine 6G. Detailed results will be described in the presentation.