Cyanine-based NIR fluorescent probe for monitoring H2S and imaging in living cells and in vivo

As a critical gaseous signaling molecule, H2S is involved in various biological processes. To deeper study the physiological and pathological roles of H2S, convenient and efficient detection techniques for endogenous H2S in vivo are still in urgent demand. Herein, we reported a new turn-on Near-infrared (NIR) fluorescence probe NIR-H2S based on thiolysis reactions for detection of H2S. The probe possessed many excellent properties including high sensitivity and selectivity, good cell-membrane permeability, and low cytotoxicity. In vitro, NIR-H2S showed a 58-fold fluorescence enhancement when reacted with H2S in a buffer and displayed a good linear relationship (r = 0.9925) in a rather wide concentration range of H2S (0-500 mu M). Furthermore, NIR-H2S was successfully employed in monitoring endogenous H2S induced by D-Cys in living cancer cells and mice. These results indicated that NIR-H2S had great potentiality in detecting cellular H2S in living animals and being applied to cancer diagnosis.