A fluorescent probe for sensing of hydrogen sulfide in living cells by adopting the adjacent-group participation strategy

Hydrogen sulfide (H ₂ S) is recognized as a critical gas signal molecule in the development and treatment of various diseases. Therefore, the development of a potent fluorescent probe for the detection of H ₂ S is of great significance in biological systems. Herein, we synthesis of a new fluorescent probe, 3-(benzo[d]thiazol-2-yl)-2-(2,4-dinitrophenoxy)-5-methylbenzaldehyde ( DPM-H ₂ S ) to detect H ₂ S based on the recognition strategy that uses an ortho-aldehyde group to facilitate the thiolysis of dinitrophenyl ether, which results in its ultrafast response to H ₂ S within 5 s together with a large Stokes shift of 106 nm. Under the excitation of 436 nm, after adding H ₂ S to the probe, the fluorescence emission at 542 nm was greatly enhanced, and the fluorescence intensity was gradually strengthened with the increase of the amount of H ₂ S, which had a good linear relationship with good limit of detection (LOD) of 4.9 µM. The probe DPM-H ₂ S reacts with H ₂ S to release its precursor 3-(benzo[d]thiazol-2-yl)-5-bromo-2-hydroxybenzaldehyde ( DPM) and realizes the fluorescence “turn on” type response. Furthermore, the probe has been successfully applied for imaging hydrogen sulfide (H ₂ S) in living HeLa cells. Additionally, the dual-side expansion strategy for regulating the optical features of traditional fluorophores could meet the increasing demands of sensing and imaging applications.