Near-Infrared Photoacoustic Probe for Reversible Imaging of the ClO–/GSH Redox Cycle In Vivo

Homeostasis of the cellular redox status plays an indispensable role in diverse physiological and pathological processes. Hypochlorite anion (ClO–) and glutathione (GSH) represent an important redox couple to reflect the redox status in living cells. The current cellular redox probes that detect either ClO– or GSH alone are not accurate enough to monitor the real redox status. In this work, a reversible photoacoustic (PA) probe, DiOH-BDP, has been synthesized and applied for PA imaging to monitor the ClO–/GSH couple redox state in an acute liver injury (ALI) model. The near-infrared PA probe DiOH-BDP features significant changes in absorption between 648 and 795 nm during the selective oxidation by ClO– and the reductive recovery of GSH, which exhibits excellent selectivity and sensitivity toward ClO– and GSH with the limits of detection of 77.7 nM and 7.2 μM, respectively. Additionally, using PA770 as a detection signal allows for the in situ monitoring of the ClO–/GSH couple, which realizes mapping of the localized redox status of the ALI by the virtue of a PA imaging system. Therefore, the probe provides a potentially technical tool to understand redox imbalance-related pathological formation processes.