▎ 摘　　要

This paper presents the fluorescence manipulation of Rhodamine-6G (R6G) due to Au nanoparticles (Au-NPs) covered by pristine graphene and hydrogen-terminated graphene. By taking florescence signals of R6G on a quartz substrate as the standard reference, we observe an similar to fourfold increase in fluorescence intensity of R6G on bare Au-NPs deposited on the quartz substrate. However, this enhancement reduces to similar to 1.8-fold when Au-NPs are covered by H-terminated graphene. In the case of Au-NPs covered by pristine graphene, the fluorescence of R6G is significantly quenched by a factor of similar to 7.6-fold. The resulting fluorescence level can be attributed to the local field enhancement from Au-NPs and the quenching effect of graphene in the Au-graphene hybrid nanostructure, which are confirmed by our controlled experimental and simulation results. Our work reveals that the surface modification of metal NPs by graphene materials would bring a great impact on fluorescence, providing a simple approach for artificially manipulating fluorescence for specific molecular sensing, detecting, and imaging.