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

[Display omitted] •A turn-on fluorescent probe for H2S has been developed.•The proposed probe employs a nitroso group as the recognition unit.•The proposed probe exhibits high selectivity, excellent sensitivity and rapid response for H2S.•The proposed probe can be used for fluorescence imaging of H2S 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 μM, with a limit detection of 29 nM (3δ). The proposed probe exhibited high selectivity, excellent sensitivity and rapid response (∼5 min) for H2S. Moreover, this probe was successfully used for fluorescence imaging of exogenous and endogenous H2S in living cells.