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

Hydrogen sulfide (HS) 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 HS in biological systems is between seconds and minutes, the development of rapid and accurate technologies for reliable monitoring HS 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 HS. Here, we constructed a novel NIR ratiometric fluorescent probe based on the "aldehyde group auxiliary strategy", Cy-HS, for the quantitative detection and precise imaging of HS in living cells and zebrafish. Cy-HS responded quickly (150 s) and was highly sensitive (0.179 μM) to HS donor. Cy-HS was further successfully employed to track endogenous HS fluctuation in HCT116 cells and zebrafish and evaluated the release efficiency of the HS prodrug in a NIR ratiometric imaging way. Cy-HS has the potential to be used as a reliable indication of HS levels in living cells and zebrafish, as well as an innovative and practical instrument for furthering the physiological research of HS, which will encourage the creation of advanced NIR ratiometric probes for a variety of biological applications.