A mitochondria-targeting near-infrared fluorescent probe for the in vivo detection of peroxynitrite

As a reactive oxygen species (ROS), endogenous peroxynitrite is closely involved in several pathophysiological processes. The development of a peroxynitrite probe would be necessary to clarify the role of peroxynitrite in pathophysiology. In this study, a new fluorescent probe TPPT was synthesized to detect peroxynitrite with high specificity and sensitivity. The results demonstrated that TPPT exhibits a fluorescence turn-on response to peroxynitrite because of the peroxynitrite-triggered oxidative reaction. The reaction product was analyzed by several methods, and the mechanism of the peroxynitrite-triggered oxidative reaction was discussed. The efficacy of TPPT for intracellular peroxynitrite imaging was demonstrated systematically. The results showed that TPPT can successfully visualize intracellular peroxynitrite in RAW264.7 cells, zebrafish, and live mouse tissues.