Colorimetric Test Kit for Cu2+ Detection

A coumarin-based colorimetric chemosensor 1 was designed and synthesized. It exhibits good sensitivity and selectivity for the copper cation over other cations such as Zn2+, Cd2+, Pb2+, Co2+, Fe2+, Ni2+, Ag+, and alkali and alkaline earth metal cations both in aqueous solution and on paper-made test kits. The change in color is very easily observed by the naked eye in the presence of Cu2+ cation, whereas other metal cations do not induce such a change. The quantitative detection of Cu2+ was preliminarily examined.