An AIE-based ratiometric fluorescent probe for reversible detection of bisulfite and hydrogen peroxide and its application in food samples and biological imaging

Reversible detection of bisulfite (HSO3-) and hydrogen peroxide (H2O2) is highly desirable in biology and food safety owing to their redox pair function in biological systems and their utilization in food industry. In this work, a ratiometric fluorescent probe (TPA-Y) with aggregation-induced emission (AIE) properties based on triphenylamine fluorophore was designed and synthesized for reversibly monitoring of HSO3-/H2O2. Reaction of HSO3- with TPA-Y can result in ratiometric fluorescence changes (I444/I629), and the emission spectrum blue shift reaches 185 nm, which can effectively avoid spectral overlap. Meanwhile, the solution color changed obviously from orange to colorless, enabling naked eye detection of HSO3-. TPA-Y was capable of quantitatively detect HSO3- in sugar and wine samples with the recovery rates ranging from 94.52 to 102.18%. In addition, TPA-Y is suitable to prepare paper strips and anti-counterfeiting ink for HSO3- detection. In addition, the original TPA-Y can be released after the addition product (TPA-Y-HSO3-) is oxidized by H2O2, and the HSO3-/H2O2 redox cycle can repeat for at least six times. The probe TPA-Y can be applied to fluorescence imaging of reversible and dynamic interconversion between HSO3- and H2O2 in living MCF-7 cells.