Super-strong interactions between multivalent anions and graphene* *Project supported by the National Natural Science Foundation of China for Outstanding Young Scholars (Grant No. 11722548), the China Postdoctoral Science Foundation (Grant No. 2019M651462), the National Natural Science Foundation of China (Grant No. U1932123), the Innovative Research Team of High-Level Local Universities in Shanghai, the Open Project of State Key Laboratory of

Abstract

Based on the density functional theory (DFT) calculations, we showed that the interactions between different valence anions (, , ) and graphene significantly increased as the valence of anion increased from negative monovalence to negative trivalence. The adsorption energy of on the electron-rich graphene flake (C84H24) is −8.3 kcal/mol. The adsorption energy of on the electron-rich graphene flake (C84H24) is –48.0 kcal/mol, which is about six times that of adsorption on electron-rich graphene flake (C84H24) and is even much larger than that of adsorption on electron-deficient aromatic ring C6F6 (–28.4 kcal/mol). The adsorption energy of on the electron-rich graphene flake (C84H24) is –159.2 kcal/mol, which is about 20 times that of adsorption on the graphene flake (C84H24). The super-strong adsorption energy is mainly attributed to the orbital interactions between multivalent anions and graphene. This work provides new insights for understanding the interaction between multivalent anions and π–electron-rich carbon-based nanomaterials and is helpful for the design of graphene-based DNA biosensor.