A near-infrared reversible fluorescent probe for real-time imaging of redox status changes in vivo

Alterations of cellular redox status are closely associated with physiological and pathological processes. Glutathione (GSH) and H2O2 should be the most representative redox couple in living cells. However, up to now, there is no way to reversibly detect GSH/H2O2. In this report, a near-infrared (NIR) fluorescent probe (Cy-O-Eb) for monitoring the changes of GSH/H2O2 levels in vivo was developed based on switching on-off a five-membered ring involved in ebselen. This probe could reversibly respond to GSH and H2O2 with high selectivity, sensitivity and mitochondrial targeting. It was successfully used to monitor the changes of redox status during apoptosis and the H2O2 changes at the wound margin in zebrafish larvae. Thus, the probe would provide an ideal tool for monitoring redox status changes and studying molecular events involved in redox regulation.