Novel Colorimetric and NIR Fluorescent Probe for Bisulfite/Sulfite Detection in Food and Water Samples and Living Cells Based on the PET Mechanism.

Despite their status of being widely used as food additives, bisulfite (HSO)/sulfite (SO) can pose serious health risks when they are excessively added. Therefore, it is vital to develop a new method for detecting HSO/SO in foodstuff. In this paper, a benzopyran-benzothiazole derivative (probe -) with near-infrared emission was designed and synthesized by constructing a "push-pull" electronic system. - can selectively recognize HSO/SO via a colorimetric and fluorescence dual channel in DMF/PBS (1:1, v/v, pH = 8.4), and the emission wavelength of - can reach 710 nm. The fluorescence quenching of - after recognition of HSO is attributed to the photoinduced electron transfer (PET) process of the adduct --HSO as evaluated by the DFT/TD-DFT method. In addition, - has many advantages, including a large Stokes shift (95 nm), good anti-interference ability, and little cytotoxicity. What's more, - has been successfully applied for the detection of HSO/SO in actual water samples and food samples such as sugar, red wine, and biscuits with satisfying results, as well as for fluorescent imaging of HSO in living MCF-7 cells.