Surface Hydrogenation and Optics of a Graphene Sheet Transferred onto a Plasmonic Nanoarray

We report properties of a plasmonic nanoarray coupled to a single layered graphene sheet transferred on the top of the nanoarray. We observe significant (up to 1000 times) enhancements of resonant Raman scattering from a graphene layer generated by near fields of a plasmonic nanoarray. This enhancement is quantitatively explained by the electromagnetic mechanism. We experimentally demonstrate a significant spectral shift of diffractive coupled plasmon resonances induced by the graphene presence and show that the collective plasmon resonances can be used to study surface chemistry of graphene. Our results emphasize prospective capabilities of graphene-functionalized plasmonics.