COX-2-targeted fluorescent probe for ClO monitoring in precise cancer detection.

Hypochlorite anion (ClO) is closely associated with cancer development and progression, necessitating precise monitoring of ClO in tumor sites, and Cyclooxygenase-2 (COX-2 is highly expressed in tumor cells. So we rationally designed two ClO-specific responsive fluorescent probes COX2-ClO1 and COX2-ClO2, using indomethacin (IMC) as the COX-2 targeting moiety and methylene blue as fluorophore unit. Both probes exhibited high selectivity and sensitivity towards ClO in the in vitro solution assays and possess excellent biocompatibility in cellular experiments. Compared to COX2-ClO1, COX2-ClO2 exhibited superior targeting specificity for COX-2, enabling precise differentiation between tumor cells and normal cells and allowing imaging of both exogenous and endogenous ClO in the in vivo experiments. Moreover, COX2-ClO2 could accurately target the tumor site in xenograft mice and is likely metabolized by the kidneys.