Fluorescence signaling of BF3 species by transformation of an ESIPT dye to its difluoroboron adduct

New selective and sensitive probes were developed for signaling chemically and industrially important, but toxic, BF3 species. These probes utilize the transformation of 2-(2- hydroxyphenyl) benzothiazole derivatives into their boron difluoride adducts. Benzothiazole-based probes demonstrated significant off-on fluorescence enhancement (I/I-0 > 2000) in the presence of BF3 species in acetonitrile. The BF3 signaling was nearly instantaneous and completed within less than 1 min. Furthermore, interference from possible BF3 decomposition contaminants, such as boric acid, HF, and BF4-, was not observed. A dye-immobilized polymer, prepared by RAFT copolymerization of dye-derived acrylamide monomer with methyl methacrylate, was successfully used for the signaling of BF3 species with a detection limit of 8.7 x 10(-8) M. These probes could be useful for the sensitive and selective fluorescent detection of important but toxic BF3 species in chemical and industrial applications. (C) 2017 Elsevier B. V. All rights reserved.