H2DCFDA will be a very good agent and it have a specificity towards H2O2. There are two process to stain the cell with H2DCFDA. After the treatment with xenobiotics you can stain the cell with 5 uM H2DCFDA. Another way you can loaded the cell with H2DCFDA and then treat the cell with your xenobitics. Then measure the % gated cell and MFI (mean fluorescence intensity) by FACS to determine the generated ROS. Be careful about the time scale of the treatment. It matters great in such experiments. All the best for your future expt.
Maybe you should find something interesting here: https://www.nationaldiagnostics.com/oxygen-assay/article/hydrogen-peroxide-detection-methods
Otherwise, the method that I usually use to estimate the oxidative stress is the quantification of the reactive oxygen species (ROS), a simple measurement that can be achieved through the 2’,7’ – dichlorofluorescin diacetate (DCFDA)