Reversible colorimetric and NIR fluorescent probe for sensing SO2/H2O2 in living cells and food samples

Preservative sulfur dioxide (SO2) and bleach hydrogen peroxide (H2O2) were widely used in the food industry, at the same time, they were also a redox pair in biological systems. Therefore, the reversible sensing SO2/H2O2 was of great significance in food safety and biology. In this paper, a colorimetric and NIR fluorescent dual channels response probe (DCA-Bba) for SO2/H2O2 based on chromene-barbiturate was developed. DCA-Bba exhibited a rapid and sensitive recognition of SO2, and the adduct DCA-Bba-HSO3- could detect H2O2 in PBS (with 10 % DMSO, v/v, pH 7.4) solution. The reversible response of DCA-Bba was implemented by HSO3- involved 1,4-addition and H2O2 induced elimination reaction. DCA-Bba showed a strong red fluorescence based on the intramolecular charge transfer (ICT) process, after the recognition of SO2, the fluorescence of the adduct was quenched based on the photoinduced electron transfer (PET) process. And importantly, DCA-Bba had been applied for imaging SO2/H2O2 redox cycles in living cells, as well as could detect the levels of SO2 in white sugar, biscuit, Chinese liquor and red wine samples.