A first principles study on electrochemical sensing of highly toxic pesticides by using porous C4N nanoflake

Abstract C4N is a novel porous two-dimensional material with fascinating electronic and chemical properties. Thereby, the sensing ability of C4N is the most aspect topic of research nowadays. In this study, potential application of C4N nanoflake as a chemical sensor for the toxic pesticides has been investigated using density functional theory calculations. The sensing ability of C4N for pesticides is evaluated through the interaction energy, noncovalent interaction index (NCI), quantum theory of atoms in molecule (QTAIM), molecular orbitals and CHELPG charge transfer analyses. The first principle calculations on ωB97XD/6-31G(d, p) level of DFT show that the C4N is selectively sensitive to Dichlorodiphenyltrichloroethane (DDT), Fenitrothion (FNT), Dimethoxy (DMDT), Ronnel (RN) and Fenthion (FT). The interaction of pesticides leads to the significant changes in the electronic structure of C4N. The observed sequence of interaction energy of our reported complexes is DDT@C4N > FNT@C4N > DMDT@C4N > RN@C4N > FT@C4N. The electronic structure changes can be demonstrated from two aspects: the strong interaction between pesticide molecule and C4N, the variation in HOMO-LUMO orbital energies and charge transfer from C4N to pesticide. The charges distribution between analytes and C4N nanoflake on interaction is analyzed by the electron density differences (EDD) and charge decomposition analysis (CDA). Our results reveal the potential application of C4N in electronic and sensor devices especially for the detection of toxic chemicals.