A dual-channel chemosensor based on 8-hydroxyquinoline for fluorescent detection of Hg2+ and colorimetric recognition of Cu2+

A novel dual-channel chemosensor, 7-allylquinolin-8-ol (AQ), was synthesized based on 8-hydroxyquinoline for selective fluorescence detection of Hg2+ and colorimetric recognition of Cu2+. The chemosensor reacted with Hg2+ and generated a new Hg-containing compound with significantly enhanced fluorescence, which turned from faint blue to strong green. Further experiments indicated that AQ could be used to quantitatively detect Hg(2+ )via fluorescence spectroscopy with a low detection limit (2.1 nM).The good reversibility of the synthesized chemosensor was also demonstrated using NaBH4. Moreover, AQ was successfully used for the detection of Cu2+ through the formation of a stable coordination compound, which exhibited an ultraviolet-visible (UV-Vis) ratiometric change, while its color changed from colorless to pale yellow under natural light. Additional experiments using various Cu2+ concentrations showed that the developed chemosensor could be further employed for the quantitative ratiometric estimation of Cu2+ by UV-Vis. (C) 2020 Elsevier B.V. All rights reserved.