▎ 摘　　要

Density functional theory calculations are carried out to understand the interactions of selected amino acids with various nitrogen-containing graphene sheets. Three types of N-containing graphene, namely pyridinic N, pyrrolic N, and graphitic N, are considered. As compared to the pristine graphene, it is found that the graphitic N could slightly enhance the interaction between amino acid and the substrate. The pyridinic N exhibits the best affinity toward the amino acids, and the increase in nitrogen content could result in more polarization in the substrate and effectively improve the interaction. In addition, the interactions between the amino acids and the hydrogenated pyridinic N and pyrrolic N in the plane and on the edge of graphene are also studied. The interaction is weakened by the hydrogenated N atom in the plane while it remains strongly for the hydrogenated N atom on the edge. The calculated charge distribution of the various nitrogen-containing graphene sheets has been illustrated, and the result shows that the pyridinic N in the plane and the hydrogenated N atom on the edge have better affinity toward the studied amino acids. This study would be useful for the practical applications of biosensor and drug delivery.