Amino Acid Monomer Ligand‐Exchanged Zeolitic Imidazolate Framework (ZIF) Based Active Site Mimicking of Peroxidase

Abstract In this study, a biomimetic horseradish peroxidase (HRP@ZIFM) containing nanohemoglobin with natural enzyme‐like activity in the presence of zeolitic imidazolate framework functional monomer (ZIFM), has been synthesized. In the first step, ZIFM has been synthesized using Zn 2+ , 2‐methylimidazole, and methacryloylhistidine. Then, the enzymatic activity of HRP@ZIFM has beeninvestigated by adding appropriate amino acid functional monomers to mimic the natural HRP active site. Horseradish peroxidase (HRP) is a heme enzyme whose active site contains heme and different amino acids. HRP oxidizes both organic and inorganic species using H 2 O 2 . The optimal pH for the enzyme peroxidase is usually between 6 and 6.5. When peroxidase is exposed to a substrate with different pH levels, the pH of the peroxidase becomes more basic. A decrease in the reaction rate is then noticed as the pH of the enzyme becomes more basic, making peroxidase more unstable. Therefore, with the synthesized ZIFM complex structure, especially using a novel approach to create multiple active centers that mimic nano‐hemoglobin‐based micromaterials integrated into stable peroxidase‐like ZIF‐nanozymes, it not only offers superior pH stability and reusability but also shows significantly higher activity, particularly with TMB substrate, compared to other synthetic or biomimetic HRPs in the literature. This provides a notable advantage for industrial and biotechnological applications.