Binding Efficiency Of Functional Groups Towards Noble Metal Surfaces Using Graphene Oxide - Metal Nanoparticle Hybrids

In this article, we present an easy and simple method to quantify binding of individual functional groups towards metal surfaces based on the fluorescence spectroscopy. An enormous literature exists about the binding of various moieties and substrates; however, majority of these methods involve molecular chemistry rather than individual functional groups. We differentiated binding of -COOH. -OH, and -NH2 functional groups towards Au, Pd and Pt surfaces using a novel methodology. For this purpose, we prepared graphene oxide hybrids with Au, Pd and Pt nanoparticles, which were optimized to have lowest fluorescence of graphene oxide, because of their binding towards nanoparticles. These hybrids were then treated with different molecules having different functional groups by titration experiments, to find the binding constants through Stern-Volmer plots. The fluorescence enhancement of these hybrids was realized through release of GO, as incoming molecules (functional groups) replaced graphene oxide from the surface of nanoparticles. The binding capacity of these functional groups towards noble metal surfaces were determining factor for the amount of released GO. Finally, a comparison of molecules containing these functional groups was made along with comparison of different surfaces, which gives us the best binding efficiencies among all.