Colorimetric Method Based on Cerium Dioxide/Iron Oxyhydroxide Nanozyme for Rapid Detection of Hydrogen Peroxide in Chicken Feet with Pickled Pepper

In this study, an innovative cerium dioxide-modified iron oxyhydroxide (CeO₂/FeOOH) nanozyme with peroxidase-like activity was synthesized by one-step hydrothermal method. The CeO₂/FeOOH nanozyme could catalyze the decomposition of hydrogen peroxide (H₂O₂) to produce hydroxyl and superoxide anion radicals, which in turn could oxidize 3,3’,5,5’-tetramethylbenzidine (TMB) to produce a blue substance (oxidized TMB, ox-TMB). Based on this, a CeO₂/FeOOH-based colorimetric sensor was constructed for the detection of H₂O₂. The results showed that the colorimetric sensor exhibited a highly sensitive response to H₂O₂ with a detection limit of 3.92 μmol/L and a linear range of 10 to 1000 μmol/L. The recoveries for spiked samples ranged from 90.59% to 93.42% with relative standard deviations (RSDs) not more than 4.25%. The developed method had the advantages of high sensitivity, high accuracy, speediness and simplicity.