Reaction-based fluorescent probe for hydrogen sulfide with large signal-to-noise ratio in living cells and tissues

Hydrogen sulfide (H2S) is now recognized as an important biological regulator and plays an important role in a vast number of physiological and pathological processes. However, understanding the important functions of H2S has remained challenging, in part due to the lack of tools for detecting endogenous H2S. Here, compound 2 was synthesized with one step reaction as a novel fluorescent turn-on probe for H2S on the basis of H2S-promoted thiolysis of dinitrophenyl ether. This free probe displayed almost no background signals due to both PET and ICT double signaling quenching mechanism. Thus, this probe shows large fluorescent turn-on and selectivity response to H2S and can be used for the fluorescence detection of both exogenous and endogenous H2S in cells with satisfactory sensitivity. Moreover, it was also applied for direct visualization of H2S in living tissues with two-photon microscopy. In addition to providing a highly sensitive and selective reaction-based fluorescent probe for H2S, the insights into the double signaling quenching mechanism controlling the signal-to-noise ratio of fluorescent turn-on probe may guide the design of fluorescent turn-on probes with better signal-to-noise ratio. (C) 2014 Elsevier B.V. All rights reserved.