Hydrogen sulfide (H2S) is a remarkable endogenous gasotransmitter involved in numerous biological processes, and its noninvasive, rapid and accurate measurement in living cells and animals is urgently needed. Herein, we report a ratiometric fluorescent H2S-specific probe (CyT). This new probe can be readily prepared by modifying the triflate group (CF3SO3−) into hemicyanine, and it shows excellent sensing properties. First, CyT is highly selective against other biologically relevant anions, cations, reactive sulfur and small molecules; meanwhile, it has a low limit of detection (LOD) to H2S (7.33 nM) In addition, CyT exhibits rapid response to H2S (rate constant is 1464 M−1 s−1) and apparent color change from dark blue to very pale green, which is observed with the naked-eye. Furthermore, it exhibits low cytotoxicity to HeLa cells and can be successfully used for the detection of H2S activity in cells and zebrafish.
