A novel FRET-based fluorescent probe for the selective detection of hydrogen sulfide (H ₂ S) and its application for bioimaging

Hydrogen sulfide (H2S) is an endogenously produced gaseous signaling molecule with multiple functions in many physiological and pathological processes. Herein, our group developed a novel fluorescent probe (Flu-N3) for H2S on the basis of the 7-amino-4-methylcoumarin and fluorescein FRET system. Adding H2S to a solution of Flu-N3 resulted in a clearly observable fluorescence enhancement (50-fold). This probe showed high sensitivity and selectivity towards H2S over other reactive species with a detection limit of 0.031 μM and a fast response time (within 8 s). Moreover, Flu-N3 displayed little toxicity to HepG-2 cells and was successfully applied to image exogenous and endogenous H2S in living cells and nude mice.