Fluorescent probe based on coumarin derivative for the selective detection of cysteine in living cells

Cysteine (Cys), an organic small molecule containing a sulfhydryl group, plays key roles in human physiology and disease. The detection of Cys in vitro and in vivo is essential for further elucidating its many biological functions. Herein, we designed and synthesized a coumarin-based fluorescent probe for Cys detection. This probe was successfully applied to the monitoring of Cys in living HeLa cells, indicating that this probe can penetrate viable cell membranes and selectively detect Cys in the presence of other analytes such as homocysteine and glutathione. The linear relationship of Cys was in the range of 0-50 µM and the limit of detection (LOD) of the probe 1 was 1.3 μM. It provides a potential possibility for the quantitative study of intracellular Cys.