A coumarin functionalized NIR fluorescent probe based on the thiopyrone skeleton for the detection of Cys and its applications

alterations in fluorescent signals. Currently, these probes have been widely employed in fields including disease biomarker monitoring, redox balance research, and drug toxicity assessment, thereby exhibiting substantial application potential in biochemical and biomedical studies. In this study, a novel fluorescent probe was designed for detecting cysteine based on the thiopyrone structure. Through characterization of its properties, it was found that this fluorescent probe exhibits a large Stokes shift (217 nm), excellent sensitivity (13.60 nM), rapid response time (3.0 min), high stability and selectivity. Furthermore, this cysteine fluorescent probe demonstrates excellent applications in RAW 264.7 cells, zebrafish, and actual samples. This study also proposes a more convenient method for testing cysteine levels using mobile phone software, and the findings indicate that the fluorescent probe under investigation has considerable potential for use in cysteine detection.