An effective colorimetric and ratiometric fluorescent probe for bisulfite in aqueous solution

•A colorimetric and ratiometric fluorescent probe was developed.•The probe could detect bisulfite in PBS buffer solution and real samples.•Bisulfite test paper was made to naked-eye detect bisulfite.•This probe successfully used to living cell imaging in ratiometric manner.

We have developed the first two-photon colorimetric and ratiometric fluorescent probe, BICO, for the detection of bisulfite (HSO3−) in aqueous solution. The probe contains coumarin and benzimidazole moieties and can detect HSO3− based on the Michael addition reaction with a limit of detection 5.3 × 10−8 M in phosphate-buffered saline solution. The probe was used to detect bisulfite in tap water, sugar and dry white wine. Moreover, test strips were made and used easily. We successfully applied the probe to image living cells, using one-photon fluorescence imaging. BICO overcomes the limitations in sensitivity of previously reported probes and the solvation effect of bisulfite, which demonstrates its excellent value in practical application.

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