Recognition of fluoride anions at low ppm level inside living cells and from fluorosis affected tooth and saliva samples

Abstract

A simple Schiff base chemosensor 2-((2-(2,4-dinitro phenyl)hydrazono)methyl)-4-nitrophenol (L) has been developed as a colorimetric and fluorimetric ‘turn on’ sensor for fluoride (F⁻). F⁻ recognition at ppm levels from mouth rinses and a toothpaste water solution has been successful. Significantly, L can detect F⁻ from fluorosis affected tooth and saliva samples by similar colorimetric changes. A test kit for F⁻ detection from a DMSO–water (1 : 1) mixture is also engineered. Intracellular F⁻ from pollen grains of Techoma stans and Candida albicans (a diploid fungus), grown in 10⁻⁶ (M) F⁻ contaminated water has been successfully detected under a fluorescence microscope.