Designed Synthesis of Compartmented Bienzyme Biocatalysts Based on Core–Shell Zeolitic Imidazole Framework Nanostructures
Gaohui Wu, Meng Li, Zhi-Gang Luo, Liang Qi, Long Yu, Shaobo Zhang, Hongsheng Liu
Abstract
Abstract For complex cascade biocatalysis, multienzyme compartmentalization helps to optimize substrate transport channels and promote the orderly and tunable progress of step reactions. Herein, a simple and general synthesis strategy is proposed for the construction of a multienzyme biocatalyst by compartmentalizing glucose oxidase and horseradish peroxidase (GOx and HRP) within core–shell zeolite imidazole frameworks (ZIF)‐8@ZIF‐8 nanostructures. Owing to the combined effects of biomimetic mineralization and the fine regulation of the ZIF‐8 growth process, the uniform shell encloses the seed (core) surface by epitaxial growth, and the bienzyme system is accurately localized in a controlled manner. The versatility of this strategy is also reflected in ZIF‐67. Meanwhile, with the ability to covalently bind divalent metal ions, lithocholic acid (LCA) is used as a competitive ligand to improve the pore structure of the ZIF from a single micropore to a hierarchical micro/mesopore network, which greatly increases mass transfer efficiency. Furthermore, the multienzyme cascade reaction is exemplified by the oxidation of o ‐phenylenediamine (OPD). The findings show that the bienzyme assembly strategy significantly affects the biocatalytic efficiency mainly by influencing the utilization efficiency of the intermediate (Hydrogen peroxide, H 2 O 2 ) between the step reactions. This study sheds new light on facile synthetic routes to constructing in vitro multienzyme biocatalysts.