Selective Visualization of the Endogenous Peroxynitrite in an Inflamed Mouse Model by a Mitochondria-Targetable Two-Photon Ratiometric Fluorescent Probe.

Peroxynitrite (ONOO-) is a kind of reactive oxygen species (ROS) with super activity of oxidization and nitration, and overproduction of ONOO- is associated with pathogenesis of many diseases. Thus, accurate detection of ONOO- with high sensitivity and selectivity is imperative for elucidating its functions in health or disease states. Herein we for the first time present a new two-photon ratiometric fluorescent ONOO- probe (MITO-CC) based on FRET mechanism by combining rational design strategy and dye-screening approach. MITO-CC, with fast response rate (within 20 s), excellent sensitivity (detection limit = 11.30 nM) and outstanding selectivity toward ONOO-, was successfully applied to ratiometric detection of endogenous ONOO- produced by HepG2/RAW264.7 cells and further employed for imaging oxidative stress in an inflamed mouse model. Therefore, probe MITO-CC could be a potential biological tool to explore the roles of ONOO- under different physiological and pathological settings.