A Novel Phthalimide-Based Turn-On Fluorescent Probe for Detection of Hydrogen Sulfide and Its Application in Real Samples.

In this paper, we rationally designed a turn-on fluorescent probe PSH for the selective and efficient detection of hydrogen sulfide (H2S) over other biologically relevant species, particularly glutathione (GSH), cysteine (Cys), and homocysteine (Hcy). Consisting of a phthalimide derivative linked with the 2,4-dinitrobenzenesulfonyl (DNBS) group through a sulfonyl ether bond, PSH exhibits a turn-on fluorescence response toward H2S with distinct advantages: a broad pH range (pH 5-9), rapid response kinetics (within 5 min), high selectivity against interfering substances (accompanied by an 8.5-fold enhancement in fluorescence intensity), and excellent sensitivity with a limit of detection (LOD) of 1.16 μM. Furthermore, PSH has been successfully applied to detect H2S in water samples, plant root samples, and living cell imaging with satisfactory results.