Immobilized Glucose Oxidase on Boronic Acid-Functionalized Hierarchically Porous MOF as an Integrated Nanozyme for One-Step Glucose Detection

Metal–organic frameworks (MOFs) with uniform porosity and large surface areas can function as carriers of immobilized enzymes. However, drawbacks including long response times or enzyme leakage have hindered their applicability. In this study, a boronic acid-functionalized hierarchically porous MIL-88B (HP-MIL-88B-BA) was prepared as an efficient immobilization matrix for glucose oxidase (GOx). HP-MIL-88B-BA features a hierarchical, porous structure with sufficient recognition sites that facilitate GOx immobilization and prevent enzyme leakage. This hierarchical porosity increased the substrate mass transfer efficiency, thereby reducing the response time. Moreover, HP-MIL-88B-BA can be used as a horseradish peroxidase mimic. In this manner, an integrated nanozyme was constructed for the rapid one-step detection of glucose. GOx@HP-MIL-88B-BA exhibited a rapid response to glucose (10 min) and displayed a good linear relationship from 2 to 100 μM with a detection limit of 0.98 μM. This novel methodology provides a straightforward, rapid, and efficient strategy for integrated nanozyme synthesis for biosensing purposes.