Novel Colorimetric and NIR Fluorescent Probe for Bisulfite/Sulfite Detection in Food and Water Samples and Living Cells Based on the PET Mechanism
Yang Li, Xiaofei Sun, Lulu Zhou, Li Tian, Keli Zhong, Jinglin Zhang, Xiaomei Yan, Lijun Tang
Abstract
Despite their status of being widely used as food additives, bisulfite (HSO3–)/sulfite (SO32–) can pose serious health risks when they are excessively added. Therefore, it is vital to develop a new method for detecting HSO3–/SO32– in foodstuff. In this paper, a benzopyran-benzothiazole derivative (probe DCA–Btl) with near-infrared emission was designed and synthesized by constructing a “push-pull” electronic system. DCA–Btl can selectively recognize HSO3–/SO32– via a colorimetric and fluorescence dual channel in DMF/PBS (1:1, v/v, pH = 8.4), and the emission wavelength of DCA–Btl can reach 710 nm. The fluorescence quenching of DCA–Btl after recognition of HSO3– is attributed to the photoinduced electron transfer (PET) process of the adduct DCA–Btl-HSO3– as evaluated by the DFT/TD-DFT method. In addition, DCA–Btl has many advantages, including a large Stokes shift (95 nm), good anti-interference ability, and little cytotoxicity. What’s more, DCA–Btl has been successfully applied for the detection of HSO3–/SO32– in actual water samples and food samples such as sugar, red wine, and biscuits with satisfying results, as well as for fluorescent imaging of HSO3– in living MCF-7 cells.