Colorimetric cyanide chemosensor based on an amide-pyrene moiety: Experimental and theoretical studies

A new simple colorimetric sensor 1 based on amide-pyrene moiety was designed and synthesized for cyanide (CN^-) in aqueous solution. The sensor 1 showed high selectivity toward CN^-, which induces an immediate color change from colorless to yellow for cyanide over other anions. Moreover, the sensor 1 could be used efficiently in a wide pH range (7-10) with no interference from other anions. The sensing of CN^- was found to be reversible with a proper reagent such as HCl. Additionally, the sensing mechanism for CN^- was theoretically supported by density functional theory and time-dependent density functional theory calculations. Therefore, sensor 1 can serve as a practical chemosensor for cyanide in aqueous solution.