A Coumarin–based Colorimetric and Fluorescent Chemosensor for the “Naked–eye” Detection of Fluoride ion in 100 % Natural Water Medium Using Coated Chromatography Plates

Abstract

AbstractBased on coumarin dye, a novel colorimetric and fluorescent dual‐modal chemosensor (CL) was designed and synthesized for fluoride ion (F–) sensing. The spectroscopic response of CL towards F– could be attributed to the F–‐triggered multi‐hydrogen bond interaction. Job's plot analysis indicates that CL forms a 1:1 stoichiometry complex with F–. The association constant (Ka) was evaluated using the Benesi–Hildebrand method and was found to be 1.986 × 103 M−1. The fluorescence detection limit for F– was estimated to be 1.5 ppb based on a 3σ/slope. CL could be easily prepared as CL‐coated chromatography plates to “naked‐eye” detect of F– in different natural water samples at a low detection limit of 1 ppm.