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

Abstract A turn-on fluorescent probe for hydrogen sulfide (H 2 S) 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 H 2 S 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 μM, with a limit detection of 29 nM (3δ). The proposed probe exhibited high selectivity, excellent sensitivity and rapid response (∼5 min) for H 2 S. Moreover, this probe was successfully used for fluorescence imaging of exogenous and endogenous H 2 S in living cells.