Construction of GOx@Fe₃O₄-HNTs Microcapsule Reactor and Its Multi-enzyme Cascade Catalytic Performance

The intracellular or intercellular microspace effectively enables various enzymatic reactions in organisms to proceed efficiently and orderly. Inspired from nature, this study combined the advantages of both natural enzymes and nanozymes to construct a microencapsulated reactor that simulates the enzymatic cascade reaction in vivo. First, the natural aluminosilicate mineral halloysite nanotubes (HNTs) were used as a carrier to in situ generate iron tetroxide (Fe3O4) with horseradish peroxidase-like activity on its surface. Then, it was used as a capsule wall material to encapsulate natural glucose oxidase (GOx), forming the GOx@Fe3O4-HNTs microcapsule reactor. When glucose is added into the system, the GOx within microcapsule reactor will first convert the glucose into gluconic acid and hydrogen peroxide (H2O2), and the H2O2 will continue to be catalyzed by Fe3O4 from the capsule wall and converted into hydroxyl radicals, triggering the color development of the substrate 3,3',5,5'-tetramethylbenzidine(TMB). Among them, Fe3O4-HNTs not only serves as the capsule wall material to protect GOx from environmental interference, but also can conduct a cascade catalytic reaction system with GOx. This kind of enzyme-nanozyme microencapsulation cascade system makes it have better catalytic performance and reaction stability than the natural enzyme systems. In addition, due to the participation of magnetic Fe3O4, the material is also recyclable and reusable. This enzyme-nanoenzyme composite microcapsule reactor provides a new method for simulating a multi-enzyme reaction system in the confined environment of organisms, and also lays a foundation for subsequent research in the fields of bioanalysis and biomimetic catalysis.