A high-contrast colorimetric and fluorescent probe for Cu2+ based on benzimidazole-quinoline

A novel colorimetric and fluorescent probe based on benzimidazole-quinoline (BMQ) was designed and synthesized. The probe exhibited high sensitivity and selectivity for Cu2+ over other cations. In addition, the color and fluorescence changes induced by Cu2+ exhibit sharp contrast. An abrupt and obvious absorption spectra shift (around 132 nm) in the visible light range (400-650 nm) is observed. The colorimetric ratio A(550)/A(418) of absorption and the concentrations of Cu2+ ranging from 0 to 100 mu mol/L show excellent linear relationship. Furthermore, the probe BMQ undergoes a complete quenching of fluorescence entered at 610 nm (98% quenching) in the present 10eq Cu2+. The detection limit of BMQ for Cu2+ was far lower than the maximum allowable level of the U.S. Environmental Protection Agency limit (20 mu M) for drinking water. (C) 2017 Published by Elsevier B.V.