An ultra-sensitive ESIPT fluorescent probe for distinguishing cancerous cells and diagnosing APAP-induced liver injury via HClO fluctuation

Hypochlorous acid (HClO) has been gradually recognized as a significant reactive oxygen species (ROS) owing to its stability in organisms. ROS concentration in cancerous cells is approximately ten times that in normal cells and excessive HClO is closely associated with tissue damage. Herein, a new turn-on fluorescent probe (MOBT-Cl) based on ESIPT for sensing HClO has been synthesized. MOBT-Cl possessed a large Stokes shift (130 nm), a rapid response time (around 10 s), and ultra-sensitivity (110-folds, LOD = 0.14 nM). Moreover, MOBT-Cl was successfully applied to imaging HClO in cells, zebrafish, and mice. Importantly, MOBT-Cl effectively distinguished cancerous cells from normal cells and monitored HClO levels in APAP-treated cells and zebrafish as well as diagnosed APAP-induced liver injury. The proposed probe held great potential for investigating the precise role of HClO in multiple physiological processes.