Colorimetric chemosensor and test kit for detection copper(II) cations in aqueous solution with specific selectivity and high sensitivity

The specific colorimetric detection of Cu2+ in the context of interference from coexisting metal ions in aqueous solution is a challenge. Therefore, a series of Cu2+ colorimetric chemosensors CS1 similar to CS3, bearing acylthiosemicarbazide moiety as binding site and nitrophenyl moiety as signal group, were designed and synthesized. Among these sensors, CS3 showed excellent calorimetric specific selectivity and high sensitivity for Cu2+ in DMSO/H2O binary solutions. When Cu2+ was added to the solution of CS3, a dramatic color change from brown to green was observed, while the cations Fe3+, Hg2+, Ag+, Ca2+, Zn7+, Pb2+, Cd2+, Ni2+, Co2+, Cr3+ and Mg2+ did not interfere with the recognition process for Cu2+. The detection limits were 5.0 X 10(-6) and 1.0 x 10(-7) M of Cu2+ using the visual color changes and UV-vis changes respectively. Test strips based on CS3 were fabricated, which could act as a convenient and efficient Cu2+ test kit. (C) 2013 Elsevier Ltd. All rights reserved.