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.