(327g) A Theoretical Understanding of Amino Acid Interaction with Graphene and Its Derivatives

As the fundamental biomolecular building blocks, amino acids are excellent simple models for understanding the interactions of biomaterials with surfaces and interfaces in biomedical applications. To the best of our knowledge, no theoretical study has been undertaken to study the dissociative interaction and the dynamic properties of amino acids on graphene oxide (GO). In this work, we performed ab initio density functional theory (DFT) calculations and reactive molecular dynamics (RxMD) simulations to study the behavior of amino acids on graphene-based surfaces, namely the pristine graphene (G), the graphene functionalized by one amine group (G-NH₂) or one carboxyl group (G-COOH), and the realistic atomistic GO models we previously developed. Pristine graphene is a hydrophobic surface while GO is considered to be hydrophilic due to the presence of planar epoxide and hydroxyl groups. The G-NH₂ and G-COOH surfaces are designed because amino acids are also composed of amine and carboxyl functional groups. The reactive interaction of amino acids with G-COOH and GO has been observed from our calculations, which is also identified in reactive adsorption measurement.