Abstract:

Metal-organic framework materials (MOFs) and covalent organic framework materials (COFs) are excellent carriers for enzyme immobilization because of their porous properties, large specific surface area, controllable structure, adjustable pore, designed framework and easy functionalization. In this paper, the structure, properties and functionalization methods of MOFs and COFs were briefly introduced, and following that, the latest research progresses of the two materials in the field of enzyme immobilization were reviewed and compared. MOFs and COFs have one-, two- and three- dimensional structures, among which three-dimensional and a small amount of two-dimensional structures show porosity. For MOFs, the functional groups can be introduced to the surface of the support by various methods including pre-modification, in-situ modification and post-synthetic modification, and enzyme can be immobilized by encapsulation, pore diffusion or surface attachment, so that a large variety of enzymes have been attempted to immobilize on them. For COFs, the functional groups were mainly introduced through post-synthesis modification and enzymes were immobilized by pore diffusion or surface attachment method. Finally, it was pointed out that MOFs had poor water or acid-base stability, the preparation conditions of COFs were harsh, and the reusability of the immobilized enzymes on MOFs and COFs was not satisfying. We should explore more effective modification strategies to improve the stability of MOFs, develop safer preparation methods of COFs, and improve reusability of the immobilized enzymes in the future.

Key words: porous materials, metal organic framework materials, covalent organic framework materials, enzyme immobilization

摘要：

金属有机框架材料（MOFs）和共价有机框架材料（COFs）具有多孔性、比表面积大、结构可修饰、孔道可调节、框架可设计、易功能化等优点，是固定化酶的优良载体。本文简要介绍了MOFs和COFs的结构、性能以及功能化方法，主要综述了这两种材料在固定化酶领域的最新研究进展，并对二者进行了比较。MOFs和COFs均具有一维、二维、三维结构，其中三维和少量二维结构呈现多孔性。通过预先修饰法、原位修饰法或后合成修饰法可在MOFs表面引入官能团，固定化酶的方法有包埋法、孔道扩散法和表面固定法，固定化酶的种类丰富；而COFs主要通过后合成修饰法引入官能团，以孔道扩散法或表面固定法固定化酶。最后指出，MOFs的水稳定性和酸碱稳定性较差，COFs的制备条件恶劣，MOFs和COFs固定化酶的重复利用性均较差，今后的发展方向是探索更为有效的修饰策略以提高MOFs的稳定性，开发更为安全的COFs制备方法，以及提高固定化酶的重复利用性。

关键词: 多孔材料, 金属有机框架材料, 共价有机框架材料, 固定化酶