IntegratedModulation of Fe, Co-MOF Nanozymes forExpressing Peroxidase-like Activity: Enhanced Affinity for H₂O₂ and Analysis of Isoniazid

The limited affinity of horseradish peroxidase (HRP) for H₂O₂ makes it unsuitable for identifying situations containing trace amounts of H₂O₂. Herein, a set of regulation schemes for Fe, Co-MOF was proposed to develop a substitute for HRP. Regarding H₂O₂ adsorption, solvent engineering allowed the MIL framework to expose the (101) crystal plane with the highest density of Lewis acid sites, and the unsaturated center of the ligand generated by the Co sites on the 1D metal–oxygen chain facilitates the adsorption of H₂O₂ in sub-nanochannels. Regarding H₂O₂ reduction, ligand amination engineering created electron donor regions. Hydrogenation engineering increased the number of Fe²⁺ as catalytic centers, and the synergy between <i>in situ</i> modified tiny AuNPs and them reduced the activation energy of the peroxidase-like reaction. Ultimately, the affinity of Fe, Co-MOF for H₂O₂ was increased by 70 times compared with HRP. As a proof-of-concept, it was used to detect isoniazid, a typical antituberculosis drug, in human urine samples.