Fluoride selective chemosensor derived from vitamin B6 cofactor pyridoxal

An easy-to-prepare and non-cytotoxic Schiff base receptor (L) is synthesized by condensation of pyridoxal with aniline. The anion sensing ability of L is explored by naked-eye, UV-vis and fluorescence methods. The receptor L shows a high selectivity and sensitivity for the sensing of fluoride anion among the other tested competitive anions. The sensor L shows both naked-eye detectable color change and significant ‘turn-on’ fluorescence at 550 nm in the presence of F- with the detection limit as low as 0.4 mM. The fluoride recognition by L is supported by 1H NMR and DFT data. The detection of cytoplasmic fluoride was tested in human cancer cell HeLa through fluorescence imaging