A novel "turn-on" fluorescent probe based on hydroxy functionalized naphthalimide as a logic platform for visual recognition of HS in environment and living cells.

A novel hydroxy functionalized naphthalimide-based fluorescent probe (denoted SP2)was successfully designed and synthesized for monitoring of HS in living cells and environmental. In particular, SP2 can detect the HS without assistance of organic solvent or surfactant. When HS is present, the azide group in SP2 was reduced to amine group, resulting in a turn-on fluorescence signal. This remarkable properties of SP2 enable its applications in monitoring ex/endogenous HS in HepG-2 cells and hydrogen sulfide release in laboratories or chemical plants through visual recognition by optical color change. The probe displays highly selective and sensitive recognition to HS, with a low detection limit of 50.8 nM. Futhermore, this work presents the possibility of using naphthalimide-based "logic gate" platform for monitoring HS in biological and environmental samples.