New Colorimetric Chemosensor for Rapid Naked-Eye Detection of Cu²⁺ and Its Application in Gas-Generating Agents

In this work, a new rhodamine derivative R1 was constructed to act as a highly effective colorimetric chemosensor for Cu²⁺ ions. The introduction of Cu²⁺ could lead to the formation of 1:1 metal-ligand complex and the rhodamine ring-opening process. Resultantly, R1 displayed marked absorbance and fluorescence enhancement with the addition of Cu²⁺ ions. Furthermore, there was a good linear relationship between the absorbance intensity change and the concentration of Cu²⁺ ions, which was beneficial for the exactly quantitative detection. R1 could serve as practical colorimetric sensors for "in-the-field" measurements that would not require any additional equipment by virtue of "dip-sticks" approach. Especially, the efficient detection of Cu²⁺ with R1 for the practical application was successfully performed in gas-generating agents detection.