Adsorption characteristics of amino acids on graphene and germanene using dispersion-corrected density functional theory

Abstract

In the present study, we have explored the interaction of five distinct kinds of amino acid molecules namely, arginine (Arg), aspartic acid (Asp), alanine (Ala), asparagine (Asn) and histidine (His) with graphene and germanene monolayers employing dispersion-corrected density functional theory . The dispersion correction incorporated in the computational methodology improves the accuracy of the results by taking into account the long range van der Waals interactions between the adsorbent and adsorbate. Using this method, the equilibrium configuration, energetic , electronic and optical properties of amino acids adsorbed on substrate have systematically been found. It is also found that arginine makes the most stable complexes with graphene and germanene in comparison to the other amino acids used in this study. Compared to graphene, germanene shows higher sensitivity to amino acids indicating that germanene monolayers can be useful for bio-integrated electronic devices. • A DFT –D2 study on the adsorption of five amino acids on graphene and germanene. • The electronic and optical properties of different complexes have been investigated. • The interaction strength of amino acids with graphene and germanene is different. • Compared to graphene, germanene shows higher sensitivity to amino acids. • A large dipole moment between the amino acid and germanene is generated.