Selective detection of F− ion and SO2 molecule: An experimental and DFT study

[Display omitted] •Inexpensive and gram-scale synthesis (∼95% yield).•A detection limit of 0.01 ppm with the permissible limit of F− ion Concentration in drinking water as mandated by WHO.•Mechanistic Investigation by DFT.•Naked-eye detection (color and fluorescence). A novel Schiff base was synthesized from acenocoumarol and aniline in gram scale in ∼95% yield. Highly selective detection of SO2 molecule and F− ion was confirmed by experiments, DFT, and TD-DFT calculations. A detection limit of 0.01 ppm, within the permissible limit of F− concentration in drinking water was achieved as mandated by WHO. The mechanism studies show that the first H-transfer is the rate determine step for the overall reaction process. The reversibility study shows the potential applicability and reusability of our sensor. An excellent binding activity was observed with SARS-CoV-2 and the binding energy was found to be −1.9 kcal/mol.