A fluorescent off–on NBD-probe for F− sensing: theoretical validation and experimental studies†
The design, synthesis and fluoride sensing ability of a 7-nitro-2,1,3-benzoxadiazole (NBD) based chemodosimeter is reported. Theoretical calculations were used to design a more applicable off–on response, by choosing NBD as the accurate fluorophore. Reaction of the NBD-probe with 300 equivalents of tetrabutyl ammonium fluoride (TBAF) exhibited a response time of 80 minutes and the reaction was selective to F− and sensing of the ion was marked by a 110-fold enhancement of green fluorescence. The off–on fluorescence characteristics of the probe enabled its application in live-cell imaging of intracellular F− ions.