An ultrafast and highly sensitive fluorescent probe for the detection of HSO3− and its application in food samples and SO2 gas

SO2 is one of the main components of air pollution gas, its derivatives HSO3− and SO32− were considerable used as food additive because of their antiseptic and bacteriostatic effects. Excessive intake of HSO3− is harmful to human health, so it is extremely important to detect the content of HSO3− in food sample by effective method. In this work, a small molecular fluorescence probe TPE-O based on tetraphenylethene fluorophore was designed and synthesized. The probe showed ultrafast (< 3 s) and obvious colorimetric response to HSO3− with high selectivity and sensitivity (LOD = 210 nM). The possible Michael-type addition of HSO3− on the activated C = C bond blocked the π-conjugated system, thus lead to changes in fluorescence and absorption spectra. Probe TPE-O not only can detect the content of HSO3− in sugar and wine, but also can be loaded on agarose hydrogel to detect SO2 gas. Therefore, this work provided a powerful tool for the detection of HSO3− in food samples and SO2 gas.