Abstract
[Display omitted]
•The probe senses SO2 derivatives with fluorescent enhancement.•The detection mechanism involves nucleophilic addition at vinylic C-atom.•Sensing mechanism was delineated using DFT and TD-DFT calculations.•The probe successfully sensed bisulphite ion in real samples.
The selective detection of sulfite and bisulfite ions with anthracene-based compounds (CN1 and CN2) as chemo-dosimeters is reported using fluorescence changes in DMSO:HEPES (70:30%), v/v buffer solution (pH 7.4). Upon treatment with sulfite and bisulfite ions, the fluorescence of the probes gets enhanced significantly at 424 nm. The detection of these ions occurs through the nucleophilic addition at the vinylic C-atom of the probes, which terminates the photo-induced electron transfer (PET) process and consequently enhances the fluorescence. This detection mechanism is well supported by 1H NMR titration, HR-MS and DFT/TD-DFT calculations. The pseudo-first-order rate constants for the addition sulfite (at pH 7.4) and bisulfite (at pH 5) to CN1 are determined to be 3.22×10−3 and 5.02×10−3 s−1, respectively. The limits of detection for sulfite and bisulfite are found to be 1.85×10−7 and 1.56×10−7 M, respectively. The probe CN1 was successfully applied to the detection of bisulfite ion in real samples.