Density Functional Theory Study of the Interaction of Arginine-Glycine-Aspartic Acid with Graphene, Defective Graphene, and Graphene Oxide

Abstract

This study investigated the interaction between carbon nanostructures, including pristine graphene, defective graphene with monovacancy, graphene oxide (GO), and tripeptide arginine-glycine-aspartic acid (RGD), by density functional theory. The results from the adsorption energy analysis show that the strongest adsorption is observed when RGD is parallel to graphene surfaces, in which graphene interacts with all three functional groups of RGD, including NH3+, COO–, and guanidine. The interaction of NH3+···π was stronger than that of guanidine–NH2···π and COO–···π. The vacancy improves the ability of graphene to attract RGD because of active dangling C atoms. GO has a stronger interaction with RGD than the pristine and defective graphene because of O-containing groups. The comparison of the GO model with the OH, epoxy, and mixed OH/epoxy groups reveals that various O-containing groups have distinguishing binding abilities with RGD. Water molecules strengthen the interactions between graphene and RGD, where...