Graphene-polyaniline composite as superior electrochemical sensor for detection of cyano explosives

Polyaniline emeraldine salt (PANI-ES) and its composite with graphene are evaluated for sensing ability towards chemical warfare agents cyanogen chloride and hydrogen cyanide. The anticipative research work is designed to compare the performance of pure PANI sensor with graphene polyaniline composite sensor for selectivity between HCN and ClCN analytes. The response mechanism is studied through geometric parameters, interaction energies, non-covalent interactions (NCI), natural bond orbital (NBO), frontier molecular orbital analysis and UV-Visible analyses. Charge analysis revealed that in all complexes, polyaniline behaves as electronic charge acceptor while analytes are the electron donors. HOMO-LUMO interaction theory is used to determine changes in conductivity after complexation. Non-covalent interaction (NCI) properties revealed the existence of van der Waals interactions between analytes and polyaniline-composite sensor. The results of thermodynamic, geometric and electronic studies conclude that both 2PANI and G54/2PANI composite sensors are more selective towards HCN than ClCN where composite sensor shows better sensitivity than simple one.