Rapid and sensitive detection of H2S by a 4-phenylselenium coumarin as a dual-active-site fluorescent probe

Hydrogen sulfide (H2S) is associated with numerous psychological and pathological processes, and related closely with human health and diseases. The detection of H2S is a key to better understand its roles. In this paper, we developed a 4-phenylselenium coumarin (PhSeCou) as a rapid-response fluorescent probe for the selective and sensitive detection of H2S. The probe PhSeCou is a stable and almost non-fluorescent molecule in a PBS buffer, and it can rapidly (< 60 s) sense H2S to give a strongly fluorescent product, Cou-H2S (Φf = 0.11, centered at 563 nm), thereby achieving to a sensitive detection at an ultra-low limit of detection (8.8 nM). The fluorescent probe displays a high selectivity for H2S over biothiols and other relevant analytes. What is more, through fluorescence cell-imaging, PhSeCou was successfully applied to detect exo- and endogenous H2S in living cells.