A novel hepatoma-specific fluorescent probe for imaging endogenous peroxynitrite in live HepG2 cells

Cell-selective imaging of some biological species is significant for the diseases research of a specific tissue or organ. Peroxynitrite (ONOO−) as a kind of reactive nitrogen species (RNS), plays extremely important roles in diverse physiological and pathological processes. Developing cell-specific fluorescent probes for tracing ONOO− in living systems remains a great challenge due to the complexity of internal environment and high autofluorescence. In this work, we developed a galactose-appended hepatoma-specific fluorescent probe Gal-NHP with hydroxynaphthalimide as the fluorophore and hydroquinone moiety as the responsive receptor for sensitively detecting endogenous ONOO− in live HepG2 cells. Probe Gal-NHP could selectively trace ONOO− without interference from other species such as HOCl and H2O2. In addition, the introduction of galactose enhanced the water solubility of this probe, and Gal-NHP could respond quickly to ONOO− in aqueous solution. The quantitative experiment showed the excellent sensitivity of this probe with a good linear relationship. Above all, fluorescence imaging results displayed it possessed excellent hepatoma-specific ability and could successfully detect endogenous ONOO− of hepatoma cells in real time. Thus, this newly developed probe would benefit to reveal the roles of ONOO− in hepatoma cells.