*4.5. H2O<sup>2</sup> and pH Measurement*

The concentration of H2O<sup>2</sup> was measured using a Hydrogen Peroxide assay kit (Beyotime, Shanghai, China). The testing solution was mixed with sample at a ratio of 1:1 (*v*/*v*). 200 µL of mixed solution was allowed to remain at room temperature for 30 min and measured at a wavelength of 570 nm using microplate reader. pH test strips were used to measure the pH value.
