A nitroso-based fluorogenic probe for rapid detection of hydrogen sulfide in living cells

A turn-on fluorescent probe for hydrogen sulfide (H2S) employing flavylium derivative as the fluorophore and nitroso group as the recognition unit and was designed and synthesized. The free probe is almost non-fluorescent. Upon addition of H2S to the solution of the probe, its nitroso group was transformed to the corresponding amino group with fast reaction kinetics, affording a dramatic enhancement of fluorescence emission. The fluorescence intensity of the proposed probe at 625 nm showed a good linear with the concentration of NaHS over a range from 0 to 4 mu M, with a limit detection of 29 nM (3 delta). The proposed probe exhibited high selectivity, excellent sensitivity and rapid response (similar to 5 min) for H2S. Moreover, this probe was successfully used for fluorescence imaging of exogenous and endogenous H2S in living cells.