A novel fluorescein-coumarin-based fluorescent probe for fluoride ions and its applications in imaging of living cells and zebrafish in vivo

A novel fluorescent probe (Flu-Si) based on fluorescein and coumarin fluorophores for highly selective and sensitive detection of F- was successfully developed. It was shown that the mechanism of recognition involves a desilylation reaction that takes place after addition of F- anions. A linear relationship between the ratio of emission intensities at 532 and 465 nm (I-532/I-465) and F- concentration over the range of 0-20 mu mol L-1 with a LOD of 0.025 mu mol L-1 was found. The sensing mechanism of Flu-Si with F- was confirmed by density functional theory (DFT) and time dependent density functional theory (TDDFT) calculation. Moreover, it was demonstrated that Flu-Si is an efficient fluorescent probe for F- anions in living cells and zebrafish, indicating its sensing potential in clinical diagnosis. (C) 2018 Elsevier B.V. All rights reserved.