Integration of enzyme immobilization and biomimetic catalysis in hierarchically porous metal-organic frameworks for multi-enzymatic cascade reactions

Multiple enzymes-induced biological cascade catalysis is indispensable in biotechnology and industrial processes. Nevertheless, the drawbacks of most natural enzymes, including poor stability and recyclability and sensitivity to the environment, have hindered their broader application. Here, we report a facile strategy to prepare a biomimetic cascade reaction system by combining the advantages of enzyme immobilization and biomimetic catalysis in a one-pot reaction system based on the hierarchically porous metal-organic frameworks (HP-MOFs). The hierarchically porous zirconium-porphyrin-based MOF (HP-PCN-222(Fe)) synthesized by modulator-induced strategy possessed tunable hierarchical porous and peroxidase-like activity, permitting them to act as not only an efficient immobilization matrix for glucose oxidase (GOx) but also peroxidase mimics to catalyze the cascade for glucose detection. A stable, anti-interference and reusable colorimetric biosensor for glucose detection was successfully established through GOx@HP-PCN-222(Fe) on the basis of the artificial tandem catalysis. Moreover, the GOx@HP-PCN-222(Fe)-fabricated electrode was available for glucose detection by electrochemical method. This work provides a potentially universal method to design functional multi-enzymatic cascade reaction systems by integrating the merits of enzyme encapsulation and biomimetic catalysis in HP-MOFs.