A molecular dynamics modelling adsorption study of Cu and Ag nanoparticles on pristine and functionalized graphene surfaces

Abstract The overuse of antibiotics has led to the flourishment of antibiotic-resistant bacteria and consequently to the need to develop new, more efficient pharmacological compounds. It is well known that graphene oxide (GO) doped with metallic particles exhibits broad-spectrum antimicrobial activity. In addition, in order to improve the pharmacokinetic behavior of these compounds and their solubility in biological media, polyethylene glycol (PEG) is attached to the graphene surface. Among the different available characterization techniques, molecular dynamics simulations (MD) deserve special attention, as they allow the study of different materials from a molecular point of view. In this work, MD simulations of the adsorption of small Ag and Cu clusters on pristine graphene and PEGylated graphene oxide (GO_PEG) surfaces were carried out. The results are presented in terms of adsorption energies, mean equilibrium distances between nanoparticles and graphene surfaces, radial distribution functions and diffusion coefficients of the metallic nanoclusters. These preliminary results show that PEGylation of the surface is critical to strengthen the interaction between the surfaces and the metallic clusters, which, in turn, is a key factor for improving the efficacy of these compounds.