High-efficiency artificial enzyme cascade bio-platform based on MOF-derived bimetal nanocomposite for biosensing

In this paper, a high-performance enzyme cascade bio-platform has been developed for biosensing by combining MOFs-based nanozyme and natural enzymes. Firstly, a novel porous mixed bi-metal oxide (MnCo₂O₄) derived from MOF with rod-like nanostructures was synthesized. Based on this, the nanozyme of bovine serum albumin-Pt nanoparticles@mesoporous MnCo₂O₄ (BSA-PtNP@MnCo₂O₄) was successfully synthesized and used to construct enzyme cascade bio-platform. The nanozyme had unique physicochemical surface properties and hierarchical structure. Due to the synergistic effect of protein, bimetal oxide and PtNP, the nanozyme presented excellent dual enzyme activity. On the one hand, BSA-PtNP@MnCo₂O₄ can be used as nanozyme with oxidase activity to achieve superior detection of glutathione with detection limit of 0.42 μM. On the other hand, BSA- PtNP@MnCo₂O₄ can also be used both as the nanozyme with great peroxidase activity and as a scaffold for immobilization of glucose oxidase (GOx), guiding an organized high-efficiency enzyme cascade bio-platform. The platform combined advantages of nanozyme and natural enzyme, and provided excellent glucose detection with the detection limit of 8.1 μM. The tandem catalytic system not only broadened the application of nanozyme in natural enzyme catalysis, but also provided a simple, efficient and organized enzyme cascade bio-platform for biosensing and other applications.