Dual-channel fluorescent probe for simultaneously detecting H2S and viscosity/polarity and its application in non-alcoholic fatty liver, tumor tissue, and food spoilage

Intracellular hydrogen sulfide (H2S) and micro-environments (e.g. viscosity and polarity) are tightly correlated with various physiological/pathological processes, making them potential biomarkers of many diseases. However, the simultaneously detecting H2S, viscosity, and polarity in inflammation, non-alcoholic fatty liver (NAFL) and tumor tissues containing clinical cancer patient samples has not been achieved yet due to the lack of effective tools. Herein, we presented a mitochondria-targeting near-infrared (NIR) fluorescent probe MQA-DNP) for simultaneously monitoring H2S, viscosity/polarity through dual channels. The probe could specifically recognize H2S via far-red emission (λem = 634 nm), and exhibited high sensitivity toward micro-environmental viscosity/polarity in the NIR channel (λem > 714 nm). Facilitated with the probe, we revealed for the first time that inflammation cells and NAFL tissues are accompanied by an up-regulation of H2S, as well as an increase in viscosity level (and/or decrease in polarity degree). Surprisingly, the simultaneous visualization of H2S, viscosity/polarity has also been achieved not only at the cancer cells and tumor models, but also in clinical cancer patients. Compared to detecting a single biomarker, the simultaneous tracking multi-markers through multi-channels seems to be more reliable for visual medical diagnosis of mitochondria-related diseases. Furthermore, inspired by the significant color changes and high sensitivity of MQA-DNP reaction with H2S, MQA-DNP has been successfully used to detect H2S released during food spoilage through test strips, and has great potential for application in complex environments systems.