Reversible colorimetric and NIR fluorescent probe for sensing SO/HO in living cells and food samples.

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