The development of stable and efficient peroxidase nanozymes is critical for advancing point-of-care diagnostic platforms. Herein, we report a ligand-engineered, defective MIL-53 nanozyme with significantly enhanced peroxidase-like activity. By introducing 4-aminonicotinic acid (4-ANA) as a co-ligand modulator during solvothermal synthesis, we successfully created a material featuring a synergistic combination of Fe-N coordination motifs, an increased density of coordinatively unsaturated Fe sites (CUS), and abundant defectassociated electronic states. These structural and electronic modifications induce coordination and defect-state modulation, which supports improved electron-transfer behavior and enhanced catalytic kinetics relative to pristine MIL-53. When integrated into a glucose oxidase (GOx)-coupled system, this enhancement translated to a high-performance colorimetric sensor for glucose, achieving a low limit of detection (LOD) of 5.5 µM alongside a wide linear range and excellent selectivity. This work presents a straightforward and effective strategy for the rational design of high-performance MOF-based nanozymes for biosensing applications.
Wang et al. (Fri,) studied this question.