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 H 2 O 2 -responsive dual-peak ratiometric NIR-II fluorescent probe (Er@Ag 2 S:Pb), made by combining H 2 O 2 -responsive fluorescent Pb-doped Ag 2 S quantum dots (Ag 2 S:Pb QDs) with a fluorescence-stabilized reference substrate NaYF 4 :Yb/Er @NaYF 4 . By monitoring the change in emitted I 1550 /I 1220 intensities the probe can be used to sense and quantify H 2 O 2 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 H 2 O 2 -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 .