A “turn-on” ESIPT fluorescence probe of 2-(aminocarbonyl)phenylboronic acid for the selective detection of Cu(II)

Herein, we report a highly selective fluorescent probe for the detection of Cu(II). The detection mechanism relies on the Cu(II)-catalyzed oxidative hydroxylation of 2-(aminocarbonyl)phenylboronic acid into salicylamide, thus recovering the excited-state intramolecular proton transfer (ESIPT) effect and inducing more than 35-fold fluorescence enhancement. The simple structure and readily available fluorescent probe give a novel method for quantitatively detecting Cu(II) in the linear range of 0–22 μM, with a limit of detection down to 68 nM, and exhibiting high selectivity for Cu(II) over 16 other metal ions.