An activatable NIR fluorescent probe for bioimaging of HOCl in cellular ferroptosis and liver injury models.

Hypochlorous acid, a prevalent reactive oxygen species, plays significantly roles in variety physiological and pathological process, such as inflammation, liver disorders, and ferroptosis. The ability to visualize and quantify HOCl in different biological contexts holds great promise for advancing understanding of disease progression and facilitating the development of targeted therapeutic strategies. Herein, we engineered a novel NIR "turn-on" fluorescent probe, TCF-NS, to detect endogenous HOCl levels in cells, mice, and zebrafish. TCF-NS exhibits rapid response, outstanding stability and selectivity, and high sensitivity, with a detection limit of 5.6 nM. TCF-NS possesses the ability to differentiate between HepG2 and L-02 cell. Through the construction of a series of models, we demonstrated that TCF-NS effectively monitors changes of HOCl levels during cell ferroptosis, drug-induced liver injury, and alcoholic liver damage. This innovative probe allows us to capture dynamic changes in HOCl levels associated with various pathological states, providing valuable insights into the underlying mechanisms of these diseases.