Real-time tracking and selective visualization of exogenous and endogenous hydrogen sulfide by a near-infrared fluorescent probe

摘要

Rapid capture and selective visualization of hydrogen sulfide (H_2S) in living systems has remained challenging. In this work, by employing ortho-aldehyde assisted thiolysis of 2,4-dinitrophenyl (DNP) ether approach and utilizing the dicyanomethylene-4H-chromene as the fluorophore, we developed a new fluorescent probe (£)-2-(2-(4-(2,4-dinitrophenoxy)-3-formylstyryl)-4H-chromen-4-ylidene) malo- nonitrile (2-CHO-OH) for this purpose with improved recognition performances. Probe 2-CHO-OH showed the advantage of quick reaction (8min) with H_2S, resulting in a strong near-infrared fluorescence emission (32-fold enhancement) and large Stokes shift (137 nm). More importantly, the probe could highly selectively detect H_2S from other biological related species including cysteine, homocysteine and glutathione with distinct dual colorimetric and fluorescent signal changes. The detection limit of H_2S was estimated as 8.3 × 10~(-8) M, which was much lower than the intracellular concentration. Thanks to these unique features, 2-CHO-OH has been successfully applied for N1R fluorescence imaging of both the exogenous and endogenous H_2S in living cells, demonstrating its value of practical application in biology.