Graphene Quantum Dots and Silver Nanoparticles Based High Sensitivity SERS Molecular Sensors

Thermal CVD graphene quantum dots and silver nanoparticles on substrates exhibit excellent enhancement factors in Raman scattering signals excited by a green solid state laser and detected by an optical spectrometer from R6G and adenine molecules of concentration lower than 10 −12 M demonstrating an enhancement factor on the order of 10 14 times for selected molecules. The applications of such devices as high-sensitivity SERS molecular sensors are presented. Roles of graphene quantum dots, silver nanoparticles and the substrates on their excellent performance are presented and discussed.