An ultrasensitive chemiluminescent probe for cysteine detection in food and biological samples.

Cysteine (Cys) plays a significant role in food analysis and biological systems. Chemiluminescence (CL) probes, which do not require external light excitation, offer excellent signal-to-noise ratios and sensitivity, making them suitable for detecting biomarkers in complex biological environments. In this study, we developed two CL probes (PF and PC) activated by Cys. PF exhibits a low detection limit (LOD = 0.013 μM), rapid response kinetics, as well as excellent selectivity and biocompatibility. Additionally, PF can be used not only for the determination of Cys in food samples but also for the detection and imaging of Cys in biological systems, including liver cancer cells, mice, and human liver cancer tissues. Notably, compared to previously reported probes, PF is the first CL probe applied to the detection of Cys in food samples. Therefore, this work holds promise as a potential tool for detecting Cys in food samples and complex biological systems.