A novel reaction-based fluorescence probe for rapid imaging of HClO in live cells, animals, and injured liver tissues

Hypochlorous acid (HClO) is an important bioactive molecule, playing vital roles in a large number of physiological and pathological processes. Abnormal concentration of HClO in vivo has close contact with many diseases including inflammatory diseases and cancer. For bioimaging HClO, a new colorimetric and turn-on near-infrared (NIR) fluorescence probe (DDAO-ClO) was designed and synthesized in this work through a specific reaction of HClO with dimethylthiocarbamate. DDAO-ClO proved to show distinct and highly selective colorimetric and NIR fluorescence responses for HClO with fast response time (<3 s) and high sensitivity (LOD = 7.3 nM) in vitro. After confirming the excellent in vitro sensing ability, imaging HClO with DDAO-ClO in living HeLa cells, MCF-7 cells, zebrafish, and mice was all successfully demonstrated. And with this probe, it was further discovered that more endogenous HClO was produced in injured mice liver tissues, which demonstrates that DDAO-ClO not only is effective for in vivo detection of HClO but also has a broad application prospect.