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

Abstract

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 ZnIrOx clusters (ZnIrOx/ZnIrMOFs) nanozyme have been synthesized by controlling the in-situ growth of ZnIrOx via a one-pot method. Notably, due to the domain-limiting effect of MOF, the ZnIrOx 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 ZnIrOx clusters. Moreover, the obtained ZnIrOx/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 2.66-319μM and 1.9μM, 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.