A novel naphthalimide-based fluorescent probe with sulfonyl hydrazide as receptor for detection of Cu2+

A novel fluorescent probe N'-(4-(2-butyl-1,3-dioxo-2,3-dihydro-1H-benzo[de] isoquinolin-6-yl)benzylidene)-4-methylbenzenesulfonohydrazide (ENM) that could selectively response to Cu2+, was reported in this paper, which was the first fluorescent probe with sulfonyl hydrazide as the receptor to detect Cu2+. The selectivity, concentration titration, pH titration, time dependence, detection limit and recognition mechanism of ENM for Cu2+ in CH3CN/H2O solution were investigated. It was shown that ENM exhibited high selectivity, sensitivity and fast response to Cu2+, and the detection limit was as low as 0.27 μmol/L. More importantly, the sensing mechanism was that ENM underwent decomposition reaction with the addition of Cu2+. In addition, ENM could work in a wide pH range. The results of determination of Cu2+ in water samples indicated that ENM had potential practical value in environmental analysis.