A new water-soluble, highly fluorogenic 3-formylBODIPY dye that enables the sensing of SO2 derivatives in aqueous buffers and cancer cells is reported. The quaternary ammonium group appended through the mesa-position of the BODIPY dye ensures water solubility. The probe exhibits high specificity for cytosolic (bi)sulfites and fluoresces brightly in human lung adenocarcinoma cells (A549). (C) 2019 Elsevier Ltd. All rights reserved.
