▎ 摘　　要

Resonance Raman spectroscopy (RRS) often suffers from the large fluorescence background which obscures the much weaker Raman scattering. To address this fundamental problem, a novel Raman substrate has been fabricated by adsorption of Au0.7Ag0.3 alloy nanoparticles (NPs) on a graphene oxide (GO) coated SiO2 surface, which offers both excellent Raman enhancement and fluorescence quenching. Our experimental data reveal that a Raman to fluorescence background intensity ratio of 1.6 can be obtained for a highly fluorescent dye like Alexa fluor 488. Moreover, we demonstrate that the Raman enhancement mainly originates from the Au0.7Ag0.3 alloy NPs and that the fluorescence quenching mainly arises from the underlying functionalized GO (FGO) substrate.