A novel fluorescent probe for imagining hydrogen sulfide upregulation in acute lung injury

Acute lung injury (ALI) is a severe pulmonary inflammatory disease with high morbidity and mortality, whose pathogenesis and treatment are still under exploration. Hydrogen sulfide (H2S), a member of gas signal molecules and a biomarker for a variety of diseases, is known to be closely related to ALI. However, the dynamic change of H2S levels in this pathological process is still unclear. Herein, a novel fluorescent probe HCy-HSP based on a sulfur-substitution hemicyanine dye was constructed through a facile routine. The probe exhibited an enhanced near-infrared emission compared to the traditional hemicyanine probes and a rapid and significant "turn-on" fluorescence response to H2S. The fluorescence imaging of endogenous H2S under different stimulation conditions in normal/cancer cells has been realized by using HCy-HSP. Furthermore, HCy-HSP has been successfully applied to the visualization of H2S levels in ALI mice via in vivo /organ near-infrared fluorescence imaging for the first time. The probe could be a promising molecular tool for exploring the physiological role of H2S in pulmonary diseases and other pathological activities.