H2O2-responsive dual-peak ratiometric NIR-II fluorescent probe for in situ hepatic oxidative stress level monitoring

Timely detection of hepatic oxidative stress is effective in preventing the onset and progression of liver disease. However, real-time and dynamic monitoring of oxidative stress in vivo remains challenging. Herein, we report a H2O2-responsive dual-peak ratiometric NIR-II fluorescent probe (Er@Ag2S:Pb), made by combining H2O2-responsive fluorescent Pb-doped Ag2S quantum dots (Ag2S:Pb QDs) with a fluorescence-stabilized reference substrate NaYF4:Yb/Er @NaYF4. By monitoring the change in emitted I1550/I1220 intensities the probe can be used to sense and quantify H2O2 concentrations ranging from 5 to 100 μM with excellent specificity. Experimental studies using mice models have shown that this probe can be used to monitor of hepatic H2O2-related oxidative stress in real time and non-invasively. Thus, the developed probe provides a powerful ratiometric NIR-II fluorescence imaging tool for timely monitoring of oxidative stress in vivo.