Tuning atomic-scale sites in metal-organic framework-based nanozymes for sensitive biosensing

Nanozymes have gained significant attention within the scientific community due to their high enzyme-like activity, low cost, high stability, and ease of preparation. Among the various nanomaterials, metal-organic frameworks (MOFs) are a type of nanozyme with a unique composition and adjustable structures. By fine-tuning at the atomic level, the catalytic activity and selectivity of MOFs can be improved, thereby expanding their application range in the field of biosensing. Herein, we summarize the recent advances on the atomic-level design of MOFs and their derivatives for sensitive biosensing. First, tuning metal ions/cluster activities and organic ligands, constructing defects and introducing axial ligands are focused on optimizing the electronic and geometrical structure of atomic-scale sites. Specifically, the underlying enzyme-like catalytic mechanisms at the atomic scale are demonstrated. Then, MOF-based nanozymes with tuned atomic-scale sites for biosensing of small biomolecules, biomacromolecules and toxic pollutants are summarized. Finally, we provide a summary and outlook on the further refinement of MOFs and their expansion in the field of biosensing applications. This review provides an overview of the methods for tuning atomic-scale sites in metal-organic framework-based nanozymes for sensitive biosensing.