Metal-organic frameworks (MOFs) have been emerged as a promising support for immobilizing enzymes owing to the tunable porosity, high surface area, and structural diversity. However, most of these possess nanometer size and small pores, which are difficult to recover them from the reaction medium and present low immobilization efficiency and protein loading capacity, and high substrate diffusion limitations. Herein, a novel magnetic amino-functionalized zeolitic imidazolate framework-8 (ZIF-8) with 3D highly ordered macroporous structure was synthesized using the assembled polystyrene (PS) nanosphere monoliths as a template. Subsequently, catalase (CAT) molecules were immobilized on the surface of macroporous magnetic ZIF-8 and inside the macropores by precipitation, covalent binding and cross-linking. The resultant immobilized CAT showed high immobilization efficiency (58%) and protein loading capacity (29%), leading to 500% higher activity than the immobilized CAT on ZIF-8 (CAT/ZIF-8). Meanwhile, the immobilized CAT could be easily recovered with a magnet without obvious activity loss. The traditional CAT/ZIF-8 lost its activity after 6 cycles, whereas, the immobilized CAT retained 90% activity of its initial activity after reusing for 8 cycles, indicating excellent reusability. In conclusion, this study provides a facile and efficient approach to immobilize enzymes on/in MOFs with enhanced activity and excellent recyclability.

由于可调节的孔隙率，高表面积和结构多样性，金属有机骨架（MOF）已成为固定酶的有前途的支持。然而，这些中的大多数具有纳米尺寸和小孔，难以从反应介质中回收它们，并且固定效率和蛋白质负载能力低，并且底物扩散限制高。本文中，以组装好的聚苯乙烯（PS）纳米球整料为模板，合成了具有3D高有序大孔结构的新型磁性氨基官能化的咪唑烷基磺酸盐骨架8（ZIF-8）。随后，通过沉淀，共价结合和交联将过氧化氢酶（CAT）分子固定在大孔磁性ZIF-8的表面和大孔内部。所得固定化CAT表现出较高的固定化效率（58％）和蛋白质负载能力（29％），比在ZIF-8上固定化CAT（CAT / ZIF-8）的活性高500％。同时，可以用磁铁容易地回收固定的CAT，而没有明显的活性损失。传统的CAT / ZIF-8在6个循环后失去了活性，而固定的CAT在重复使用8个循环后仍保留了其初始活性的90％，表明其具有出色的可重复使用性。总之，这项研究提供了一种简便而有效的方法，可将酶固定在MOF上/之中，具有增强的活性和出色的可回收性。固定的CAT可以很容易地用磁铁回收，而没有明显的活性损失。传统的CAT / ZIF-8在6个循环后失去了活性，而固定的CAT在重复使用8个循环后仍保留了其初始活性的90％，表明其具有出色的可重复使用性。总之，这项研究提供了一种简便而有效的方法，可将酶固定在MOF上/之中，具有增强的活性和出色的可回收性。固定的CAT可以很容易地用磁铁回收，而没有明显的活性损失。传统的CAT / ZIF-8在6个循环后失去了活性，而固定的CAT在重复使用8个循环后仍保留了其初始活性的90％，表明其具有出色的可重复使用性。总之，这项研究提供了一种简便而有效的方法，可将酶固定在MOF上/之中，具有增强的活性和出色的可回收性。