MOF-confined ultrafine nanozymes with enhanced catalysis for sensitive colorimetric detection of glucose

The constrained enzymatic activity and aggregation challenges encountered of nanozymes pose an obstacle to their practical utility, necessitating a strategy to alleviate this problem and improve the enzymatic catalytic efficiency. Herein, MOF-confined ultrafine ZnIrO x clusters (ZnIrO x /ZnIrMOFs) nanozyme have been synthesized by controlling the in-situ growth of ZnIrO x via a one-pot method. Notably, due to the domain-limiting effect of MOF, the ZnIrO x clusters with small size grew uniformly in the structure of ZnIrMOFs nanosheets, while the presence of Zn atoms improved the crystallinity of the MOF phase and the dispersion of ZnIrO x clusters. Moreover, the obtained ZnIrO x /ZnIrMOFs exhibited excellent oxidase- and peroxidase-like activities and better substrate affinity, which can directly and effectively catalyze chromogenic reaction to produce corresponding color and signal changes. Adopting this strategy, we established a visual, sensitive, and selective colorimetric method for glucose detection with a linear range and detection limit of 2.66–319 μM and 1.9 μM, respectively. The successful detection of glucose in real serum and food samples implies the promising MOF-confined ultrafine nanozymes in biomedical diagnostics and in food industry.