Visualizing Peroxynitrite in Microvessels of the Brain with Stroke Using an Engineered Highly Specific Fluorescent Probe.

Stroke is one of the leading causes of death and disability in the world, which is associated with malfunction of reactive oxygen species and reactive nitrogen species (ROS/RNS) in cerebral microvessels. In vivo monitoring these species, such as ONOO-, with high selectivity in stroke process is of great significance for early diagnoses and therapies of the disease. Herein, by engineering an indoline-2,3-dione moiety as the recognizing domain, we proposed a novel fluorescence probe Rd-PN2 with highly specific response toward ONOO-, even in the coexistence of other ROS/RNS with high concentration. Rd-PN2 showed high sensitivity and reaction speed in response to ONOO- and exhibited satisfying performances in tracking the endogenously generated ONOO- in living cells and zebrafish. Accordingly, Rd-PN2 can furnish real-time and in vivo visualizing of ONOO- in cerebral microvessels of mice with ischemic and hemorrhagic strokes under two-photon microscopy. This work presented a precisely modulated fluorescence probe for real-time visualizing of ONOO- production in cerebral micovessels, which will also help to acquire more accurate information in the studies of ONOO- functions in the future.