The maiden report of a fluorescent-colorimetric sensor for expeditious detection of bifluoride ion in aqueous media

A fluorescent-colorimetric chemosensor L, for rapid detection of bifluoride ion has been developed based on a simple bis-Schiff base. The chemosensor L is easy to synthesize, eco-friendly and cost effective. It exhibits an unprecedented selectivity and sensitivity towards bifluoride ion through change in absorption as well as fluorescence intensity. The anion recognition occurs through intermolecular H-bond formation exhibiting colour change from yellow to colourless. The structure of the ligand and its sensing behaviour is well established by DFT and electrochemical studies. The sensitivity of the fluorescence based assay (0.62 mu M) for bifluoride ion is the lowest ever reported in the literature. The chemosensor L, providing rapid response time with sufficiently low detection limit may be useful as a valuable practical sensor for analysis of bifluoride ion in environmental samples.