Visual detection of fluoride ion based on ICT mechanism.

A novel chemosensor (HNTS) has been designed for a fast and accurate detection of F in acetonitrile medium. The UV-Vis, H, C NMR experiments and computational calculations demonstrate that HNTS probe offers a potential colorimetric sensor for discriminating F among other relevant anions. The detection limit is as low as 6 μM and a reversible colorimetric switch could be devised by sequential addition of F/Ca. The promising application of HNTS is also confirmed in real examples where the concentration of F is a critical parameter, e.g., commercial toothpaste, paper strip and gel form analysis of samples.