Highly selective "turn-on" fluorescent and colorimetric sensing of fluoride ion using 2-(2-hydroxyphenyl)-2,3-dihydroquinolin-4(1 H)-one based on excited-state proton transfer

Abstract

A simple, highly selective and sensitive colorimetric system for the detection of fluoride ion in an aqueous medium has been developed using 2-(2-hydroxyphenyl)-2,3-dihydroquinolin-4(1 H)-one. This system allows selective "turn-on" fluorescence detection of fluoride ion, which is found to be dependent upon guest basicity. An excited-state proton transfer is proposed to be the signaling mechanism, which is rationalized by DFT and TD-DFT calculations. The present sensor can also be applied to detect fluoride levels in real water samples. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.