A novel 3,6-diamino-1,8-naphthalimide derivative as a highly selective fluorescent turn-on probe for thiols

A novel 1,8-naphthalimide derivative bearing 3-amino and 6-(2,4-dinitrobenzenesulfonamido) groups was synthesized and found to exhibit a fluorescent turn-on response to biothiols, including Cys, Hcy and GSH. This compound exhibited high selectivity and low detection limit, in particular toward Cys. The sensing mechanism involved the cleavage of the 2,4-dinitrobenzenesulfonamido group and the formation of an electron-donating amino group. In addition, its properties for cellular imaging were also briefly discussed.