A mitochondria-targeted fluorescent probe for ratiometric detection of H2S and its application in monitoring food freshness and bioimaging

Hydrogen sulfide (H2S) is a colorless gas was produced during the spoilage of sulfur-riched foods, it is also multi-functional signaling molecule and plays an essential in diverse physiological systems. Here, a ratiometric fluorescent probe (TD) for monitoring H2S was rationally prepared. TD displayed red emission due to strong intramolecular charge transfer (ICT) effect between the electron-donating phenol group and the electron-withdrawing benzindole group. Upon reaction with H2S, the extended π-conjugation system was broken, leading to ICT effect was turned off and caused a distinctive colorimetric and fluorometric response. Importantly, the probe-based test strip was developed for real-time monitoring of H2S generated during food spoilage, which enabling on-site visualization detection of food freshness. Meanwhile, the practical applicability of TD to detect H2S were also evaluated in water, wine, and living cells. These results such as rapid response, exceptional selectivity and sensitivity establish a foundation to develop a highly sensitive and accurate analytical method for monitoring H2S.