Reversible near-infrared fluorescent probe introducing tellurium to mimetic glutathione peroxidase for monitoring the redox cycles between peroxynitrite and glutathione in vivo.

The redox homeostasis between peroxynitrite and glutathione is closely associated with the physiological and pathological processes, e.g. vascular tissue prolonged relaxation and smooth muscle preparations, attenuation hepatic necrosis, and activation matrix metalloproteinase-2. We report a near-infrared fluorescent probe based on heptamethine cyanine, which integrates with telluroenzyme mimics for monitoring the changes of ONOO(-)/GSH levels in cells and in vivo. The probe can reversibly respond to ONOO(-) and GSH and exhibits high selectivity, sensitivity, and mitochondrial target. It is successfully applied to visualize the changes of redox cycles during the outbreak of ONOO(-) and the antioxidant GSH repair in cells and animal. The probe would provide a significant advance on the redox events involved in the cellular redox regulation.