SERS Sensing Properties of New Graphene/Gold Nanocomposite.

The development of graphene (G) substrates without damage on the sp2 network allows to tune the interactions with plasmonic noble metal surfaces to finally enhance surface enhanced Raman spectroscopy (SERS) effect. Here, we describe a new graphene/gold nanocomposite obtained by loading gold nanoparticles (Au NPs), produced by pulsed laser ablation in liquids (PLAL), on a new nitrogen-doped graphene platform (G-NH2). The graphene platform was synthesized by direct delamination and chemical functionalization of graphite flakes with 4-methyl-2-p-nitrophenyl oxazolone, followed by reduction of p-nitrophenyl groups. Finally, the G-NH2/Au SERS platform was prepared by using the conventional aerography spraying technique. SERS properties of G-NH2/Au were tested using Rhodamine 6G (Rh6G) and Dopamine (DA) as molecular probes. Raman features of Rh6G and DA are still detectable for concentration values down to 1 × 10-5 M and 1 × 10-6 M respectively.