Two novel coumarin-based fluorescent probes for the detection of Cu2+ and biological applications

Large accumulations of copper (Cu) ions in the human body may cause damage, including organ and brain damage. In recent years, studies have proven that a large accumulation of Cu ions can lead to Parkinson's disease and Alzheimer's disease; therefore, it is great important to develop novel strategies for detecting trace Cu in environmental and biological samples. In this work, we designed two new coumarin-based colorimetric and fluorescent probes, HQ1 and HQ2. These two probes could selectively respond to Cu2+ with obvious color and fluorescence changes, and the presence of other metal ions had no effect on these changes. The two probes also exhibited high sensitivity for Cu2+, with a detection limit as low as 1.81 x 10-8 M/1.57 x 10-8 M. Notably, the two probes showed potential practical applications and were successfully used for detecting Cu2+ in a test strip, A549 cells, and living zebrafish larvae.