Abstract:

Two-dimensional nanomaterials have high mechanical strength and specific surface area, a large number of surface functional groups, good hydrophilicity and biocompatibility, and are good carriers for enzyme immobilization. In this paper, classical graphene oxide (GO) and new transition metal carbon/nitrogen compounds (MXenes) were selected, and their preparation methods, structure, physical and chemical properties were introduced respectively. Their applications in the field of enzyme immobilization were reviewed and compared. GO is prepared from graphene by chemical oxidation and then peeled. MXene is prepared from its precursor by etching. Materials prepared by different oxidation or etching methods have differences in composition, structure and properties. There are more reactive functional groups on GO surface, including hydroxyl, carboxyl and epoxy groups, so it is widely used in the field of enzyme immobilization. Enzyme is immobilized on MXenes mainly by the reaction with hydroxyl groups or the adsorption on the negative charges on the surface, and current major application is in biosensors. At last, it is pointed out that there are still some problems for the two kinds of materials, such as low preparation efficiency, easy agglomeration of nanosheets and poor recyclability. The future development directions are to develop simpler and safer material preparation methods, explore more effective means of intercalation and stripping, and improve the recycling strategies of the immobilized enzymes, so as to further promote the application of two-dimensional nanomaterials in the field of enzyme immobilization.

Key words: two-dimensional nanomaterials, graphene oxide, transition metal carbon/nitrogen compounds, enzyme immobilization

摘要：

二维纳米材料具有高机械强度和比表面积、大量表面官能团、良好的亲水性及生物相容性，是固定化酶的良好载体。本文选取经典的氧化石墨烯（GO）以及新型的过渡金属碳/氮化合物（MXenes），分别介绍了它们的制备方法和结构、物理和化学性质，综述了它们在固定化酶领域的应用研究，并进行了比较。文中指出：GO由石墨烯经化学氧化再剥离制得，MXenes由其前体经刻蚀制得，不同的氧化或刻蚀方法制得的材料在组成、结构、性能等方面存在差异。GO表面的可反应官能团更多，包括羟基、羧基和环氧基，故在固定化酶领域应用广泛。MXenes固定化酶则主要利用表面的羟基反应或负电荷吸附，目前主要用于制备生物传感器。最后指出这两种材料还存在制备效率低、纳米片易聚集、循环利用性差等问题。今后的发展方向是要开发更为简单和安全的材料制备方法，探索更为有效的插层和剥离手段以及改善固定化酶的回收策略，进一步推进二维纳米材料在固定化酶领域的应用。

关键词: 二维纳米材料, 氧化石墨烯, 过渡金属碳/氮化合物, 固定化酶