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

摘要

Based 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-hydro- gen bond interaction. Job’s plot analysis indicates that CL forms a 1:1 stoichiometry complex with F~- . The association con- stant (K_a) was evaluated using the Benesi–Hildebrand method and was found to be 1.986 3 10~3 M~(-1) . The fluorescence de- tection limit for F~- was estimated to be 1.5 ppb based on a 3σ/ slope. CL could be easily prepared as CL-coated chromatog- raphy plates to “naked-eye” detect of F~- in different natural wa- ter samples at a low detection limit of 1 ppm.