Metal–Organic Framework as a Compartmentalized Integrated Nanozyme Reactor to Enable High-Performance Cascade Reactions for Glucose Detection

Integrated nanozymes have recently attracted intense attention because of their promising applications in many fields, including biosensing. However, methods to efficiently activate cascade reactions remain challenging when designing and constructing integrated nanozymes. Herein, inspired by the compartmentalization and substrate-channeling effects of natural enzymes in organisms, a metal–organic framework (MOF)-based integrated nanozyme was prepared by encapsulating a natural enzyme (GOx) within the copper 1,4-benzenedicarboxylate (CuBDC) MOF nanozyme via a one-step biomimetic mineralization process at room temperature. Benefiting from the highly ordered peroxidase-like active sites in CuBDC and the confinement effect of CuBDC, the compartmentalization and substrate-channeling effects were achieved in the GOx@CuBDC integrated nanozyme. Surprisingly, the GOx@CuBDC integrated nanozyme displayed a 12.5-fold enhancement compared with the cascade reaction system using free GOx and CuBDC in detecting glucose. Furthermore, this biosensor exhibited a good linear relationship in the concentration range 10–500 μM, with a low detection limit of 4.1 μM (S/N = 3), and also demonstrated excellent stability, reusability, and selectivity. This work may spark a new design strategy for high-performance integrated nanozymes.