Si-coumarin-based fluorescent probes for ultrafast monitoring H₂S in vivo

Fluorescent probes with high sensitivity, selectivity, and fast response are urgently required for fluorescent imaging. The introduction of silicon atom into coumarin skeleton have resolved abrupt and instant increment in fluorescent quantum yield (from 0.002 into 0.93) when the 3-azide was reduced to 3-amine. The hydrogen sulfide triggered reduction process has ultrafast kinetic and reached equilibrium within 25 s. A group of silicon substituted coumarins SiC-Azs were designed for sensitively monitoring cellular hydrogen sulfide in vivo. The probe SiC-Az2 can be highly selective and sensitive to monitor endogenous and exogenous hydrogen sulfide in Hela cells and zebrafish.