Surface-generated copper ions induce multilayer growth of small peptides

Abstract Herein, we investigate the adsorption behavior of a small peptide, Glu-Cys-Gly, in aqueous solution onto copper surface and unravel a mechanism of growth of a hybrid peptide-copper multilayer the thickness of which may exceed a hundred of nanometers. Thanks to a combined set of surface characterizations supported by theoretical considerations, we provide a comprehensive understanding of the driving force and parameters influencing multilayer growth. (i) The generation of Cu+ ions due to the dissolution of copper surface, modulated by pH, results in the formation of cuprous-thiolate complex made of two peptide molecules anchoring one Cu+ cation. (ii) The stability of this hybrid multilayers is ensured by intermolecular interactions between peptide-copper entities mainly through a combination of electrostatic interaction and hydrogen bonds which stabilize the supramolecular edifice.