A NIR ratiometric fluorescent probe for the rapid detection of hydrogen sulfide in living cells and zebrafish

Hydrogen sulfide (H₂S) acts as a gas transporter and cell protector and plays a role in a number of disorders and signaling processes. Given that the half-life of H₂S in biological systems is between seconds and minutes, the development of rapid and accurate technologies for reliable monitoring H₂S levels and dynamics in organisms is critical. However, it is still difficult to design innovative near-infrared fluorescent probes that can quickly and accurately detect H₂S. Here, we constructed a novel NIR ratiometric fluorescent probe based on the "aldehyde group auxiliary strategy", Cy-H₂S, for the quantitative detection and precise imaging of H₂S in living cells and zebrafish. Cy-H₂S responded quickly (150 s) and was highly sensitive (0.179 μM) to H₂S donor. Cy-H₂S was further successfully employed to track endogenous H₂S fluctuation in HCT116 cells and zebrafish and evaluated the release efficiency of the H₂S prodrug in a NIR ratiometric imaging way. Cy-H₂S has the potential to be used as a reliable indication of H₂S levels in living cells and zebrafish, as well as an innovative and practical instrument for furthering the physiological research of H₂S, which will encourage the creation of advanced NIR ratiometric probes for a variety of biological applications.