A ratiometric fluorescence probe for bisulfite detection in live cells and meat samples

The development of reliable probe technology for the detection of bisulfite (HSO₃^-) in situ in food and biological samples is contributing significantly to food quality and safety assurance as well as community health. In this work, a responsive probe, EHDI, is developed for ratiometric fluorescence detection of HSO₃^- in aqueous solution, meat samples, and living cells. The probe is designed based on the HSO₃^- triggered 1,4-addition of electron deficit C = C bond of EHDI. As a result of this specific 1,4-addition, the π-conjugation system was destructed, resulting in blue shifts of the emission from 687 to 440 nm and absorption from 577 to 355 nm. The probe has good water solubility, high sensitivity and selectivity, allowing it to be used for imaging of HSO₃^- internalization and production endogenously. The capability of probe EHDI for HSO₃^- was then validated by traditional HPLC technology, enabling accurately detect HSO₃^- in beef samples. The successful development of this probe thus offers a new tool for investigating HSO₃^- in situ in food and biological conditions.