A Novel Rhodamine-Based Fluorescent Sensor for Detection of Cu.

In this work, a new fluorescent sensor for detecting Cu was developed based on the Rhodamine derivative. It displayed strong fluorescence enhancement upon the addition of Cu, and other common metal ions do not significantly affect the optical properties of the sensor. This optical signal change caused solely by Cu is due to the opening of the lactone amide spiro ring structure, resulting in fluorescence emission. This specific recognition endows the sensor with the ability to qualitatively and quantitatively detect Cu, and the conclusion was also verified through density functional theory calculations. Simultaneously, the cell imaging and zebrafish experiments proved the potential application value in biological systems.