Facile decoration of Au nanoparticles on reduced graphene oxide surfaces via a one-step chemical functionalization approach

A facile way to fabricate functionalized and reduced graphene oxide (RGO) was reported by introducing the dual-function reagent N-1-(3-trimethoxysilylpropyl) diethylenetriamine (TSPD), in which (i) the amine functional groups of the organosilane can effectively restore the pi bonds of the GO; and (ii) the silanol parts react with the hydroxyl groups of GO and subsequently cross-link to form a monolayer on the graphene surface. The exposed amine groups of the functionalized GO could effectively template the Au nanoparticles (AuNPs) assembly on the graphene surface with high density and good dispersity. TEM images indicate that AuNPs retained their original size and were well-anchored on the graphene surfaces with an average inter-particle distance of 15 nm. The resultant graphene sheets decorated by AuNPs has the capability of sensing single molecules on its surface, e. g., Rhodamine 6G (Rh6G), through the surface-enhanced Raman spectroscopy (SERS).