GOx@Fe_(3)O_(4)-HNTs微囊反应器的构筑及多酶级联催化性能

Construction of GOx@Fe_(3)O_(4)-HNTs Microcapsule Reactor and Its Multi-enzyme Cascade Catalytic Performance

细胞内或细胞间的微空间使得生物体内的各种酶促反应能够高效有序地进行.基于此,本文结合天然酶-纳米酶二者的优势,构筑了一种模拟体内酶促级联反应的微囊反应器.首先,以天然硅铝酸盐矿物埃洛石纳米管(HNTs)为载体,在其表面原位生成具有类辣根过氧化物酶活性的四氧化三铁(Fe3O4);随后,将其作为囊壁材料封装天然葡萄糖氧化酶(GOx),构筑GOx@Fe3O4-HNTs微囊反应器.当向体系中加入葡萄糖时,微囊反应器内的GOx先将葡萄糖转化为葡萄糖酸和过氧化氢(H_(2)O_(2)),之后H_(2)O_(2)继续被囊壁中的Fe_(3)O_(4)催化转化为羟基自由基,触发底物3,3',5,5'-四甲基联苯胺(TMB)显色.其中,Fe_(3)O_(4)-HNTs作为囊壁材料不仅使囊内GOx免受外界环境干扰,还可与GOx构建级联催化反应体系,这种酶-纳米酶微囊化级联体系具有比天然酶系统更优异的催化性能和反应稳定性.此外,因磁性Fe_(3)O_(4)的参与,材料还具有可回收性和重复使用性.这种酶-纳米酶复合微囊反应器为模拟生物体内限域环境下的多酶反应体系提供了新方法,同时为后续生物分析与仿生催化领域的进一步研究奠定了基础.

The intracellular or intercellular microspace effectively enables various enzymatic reactions in organisms to proceed efficiently and orderly.Inspired from nature,this study combined the advantages of both natural enzymes and nanozymes to construct a microencapsulated reactor that simulates the enzymatic cascade reaction in vivo.First,the natural aluminosilicate mineral halloysite nanotubes(HNTs)were used as a carrier to in situ generate iron tetroxide(Fe_(3)O_(4))with horseradish peroxidase-like activity on its surface.Then,it was used as a capsule wall material to encapsulate natural glucose oxidase(GOx),forming the GOx@Fe_(3)O_(4)-HNTs microcapsule reactor.When glucose is added into the system,the GOx within microcapsule reactor will first convert the glucose into gluconic acid and hy⁃drogen peroxide(H_(2)O_(2)),and the H_(2)O_(2)will continue to be catalyzed by Fe_(3)O_(4)from the capsule wall and converted into hydroxyl radicals,triggering the color development of the substrate 3,3',5,5'-tetramethylbenzidine(TMB).Among them,Fe_(3)O_(4)-HNTs not only serves as the capsule wall material to protect GOx from environmental interference,but also can conduct a cascade catalytic reaction system with GOx.This kind of enzyme-nanozyme microencapsulation cascade system makes it have better catalytic performance and reaction stability than the natural enzyme systems.In addition,due to the participation of magnetic Fe_(3)O_(4),the material is also recyclable and reusable.This enzyme-nanoenzyme composite microcapsule reactor provides a new method for simulating a multi-enzyme reaction system in the confined environment of organisms,and also lays a foundation for subsequent research in the fields of bioanalysis and biomimetic catalysis.