Design, Synthesis, and Cytotoxicity Assessment of a Novel Fluorescent Probe for Cysteine Detection

Abstract

Cysteine (Cys) is a sulfur-containing amino acid that plays a vital role in numerous biological processes, including protein synthesis, redox homeostasis, and cellular metabolism. Abnormal Cys levels have been associated with various diseases, creating a growing demand for the development of fluorescent probes for its detection. In this study, a new pyridinium–benzothiazole-based fluorescent probe was designed and synthesized as a potential molecular platform for Cys sensing. The structure of the synthesized compound was successfully confirmed by 1H and 13C NMR spectroscopy. To evaluate its suitability for biological applications, cytotoxicity studies were carried out, and the probe exhibited favorable biocompatibility under the tested conditions. These results demonstrate that the synthesized probe is a suitable candidate for further investigations in fluorescence-based sensing studies. Overall, the newly developed pyridinium–benzothiazole derivative provides a useful foundation for the future development of Cys-responsive fluorescent probes and related biological applications.