Cascade reaction-based rapid and ratiometric detection of H2S/S2- in the presence of bio-thiols with live cell imaging: demasking of ESIPT approach

For the rapid, ratiometric, fluorogenic and naked eye detection of H2S/S2-, a pro-excited state intramolecular proton transfer (ESIPT)-based receptor, 2-formyl-benzoic acid 2-benzothiazol-2-yl-phenyl ester (FBBP) has been designed. In the presence of H2S/S(2-)in preference to other common species, 2-(2-hydroxyphenyl)benzothiazole, a well known ESIPT-containing agent, is recovered from FBBP. Thus, H2S/S(2-)can be detected in vitro and in vivo by such a simple, easy-to-synthesise, practical ratiometric sensor.