Adsorption elucidation of amino acids on diamond-like carbon coatings for biomedical applications using dispersion-corrected DFT

Abstract

Understanding the interactions between biomolecules (proteins) and nanomaterials surface is of great importance for developing new biomedical devices. Diamond-like carbon (DLC) is considered an excellent candidate for coating materials for bone organ and tooth replacement. In this paper, Dispersion-corrected Density Functional Theory (DFTD) calculations were performed to elucidate the adsorption behavior of amino acid molecules over Diamond-Like Carbon (DLC) coatings surfaces.In order to examine the effect of carbon hybridization (sp3/sp2 ratio) on the adsorption process, three kinds of DLC surfaces are selected DLC1, DLC2, and DLC3 with sp3/sp2 ratios of 20/80, 52/48, and 76/24 respectively. Molecular optimization, electronic properties, molecular electrostatic potential (MEP), the density of states (DOS), and Infrared analysis for DLC surfaces and amino acids before and after adsorption are investigated. NBO and QTAIM results reveal that the adsorption is physical in nature owing to the presence of non-covalent bonds between the considered molecules. DLC1 with a low sp3/sp2 ratio has more affinity to amino acids than DLC2 and DLC3.