A phosphine-based fluorescent probe for fluorescent imaging of hypochlorous acid in living cells and zebrafish

Hypochlorous acid (HOCl) is crucial in various physiological processes, and monitoring its level in organisms is essential for understanding its biological functions and pathological effects. In this study, we developed a novel fluorescent probe based on dicyclohexylphosphine for rapid and sensitive detection of HOCl in an aqueous solution. The probe exhibits a significant fluorescence turn-on response to HOCl through the specific oxidative reaction between dicyclohexylphosphine and HOCl. It possesses high selectivity, instantaneous response (approximately 1 s), and a low detection limit of 15.3 nM. Moreover, biological imaging results demonstrated that the probe could be used for real-time fluorescence imaging of HOCl in living cells and zebrafish. The development of this probe may provide new insights into designing phosphine-based fluorescent probes for detecting oxidative species.