A near-infrared fluorescent probe for imaging hydrogen peroxide in living cells and acute liver injury.

Acute liver injury (ALI) is linked to oxidative stress, with hydrogen peroxide H2O2 as a key mediator. We report a near-infrared fluorescent probe, PhCy-H2O2, based on an ICT mechanism. The probe shows high sensitivity (detection limit in the low micromolar range) and excellent selectivity, producing a significant fluorescence turn-on at 796 nm upon H2O2 recognition. This reaction has the advantages of high sensitivity, high selectivity, fast reaction and stability under physiological pH conditions. In both cellular and mice models, the probe clearly visualized dose-dependent H2O2 generation induced by LPS and APAP, with fluorescence signals effectively attenuated by GSH and NAC, respectively, confirming the observed signals are associated with oxidative stress. Moreover, the hepatic fluorescence intensities correlated well with the levels of MDA and TNF-α, and the signal changes faithfully reflected the protective effects of antioxidant interventions, indicating that the probe reliably reports the severity of oxidative injury in ALI. Thus, PhCy-H2O2 offers a reliable tool for studying oxidative stress in ALI and evaluating hepatoprotective agents.