Spectrophotometric quantification of hydrogen peroxide utilizing silver nanozyme

In this contribution, an analytical method was developed utilizing silver nanozymes as inexpensive and high throughput nanomaterials with high peroxidase-like activity for the selective quantification of hydrogen peroxide in food samples. 3,3’,5,5’-tetramethylbenzidine (TMB) was utilized as peroxidase substrate to produce the blue-colored analytical probe. The method was constructed based on the spectrophotometric probing the oxidation product of TMB by hydrogen peroxide in the presence of silver nanozyme as catalyst and the absorbance of the blue-colored oxidation product at 658 nm was used as analytical signal. The effective parameters on the method sensitivity including nanozyme amount, incubation time, buffer type and concentration, pH, and substrate concentration were optimized. In optimal experimental conditions, a linear dynamic range of 1-80 μM and detection limit as low as 0.12 μM were obtained. Besides, the selectivity studies revealed that the absorbance at 658 nm was increased in the presence of hydrogen peroxide while other co-existing species cannot proceed the oxidation process. Finally, the designed method was applied to quantify hydrogen peroxide of milk samples, revealing highly accurate results. The results of this research can be potentially utilized for food safety verification in food industries.