Wang Jin, Qin Yunlong, Carmieli Raanan, Gutkin Vitaly, Pikarsky Eli, Zhang Zhen, Chen Xinghua, Willner Itamar
Institute of Chemistry, The Hebrew University of Jerusalem Jerusalem 91904 Israel
School of the Environment and Safety Engineering, Jiangsu University Zhenjiang 212013 China
Chem Sci. 2025 May 1. doi: 10.1039/d5sc01972a.
Fe-doped ZIF-90 (Fe-ZIF-90), a metal-organic framework (MOF), was synthesized and characterized. The MOF particles reveal peroxidase-like activity reflected by catalyzing the HO oxidation of 3,3',5,5'-tetramethylbenzidine, TMB, to TMB˙. Integration of the two enzymes, β-galactosidase, β-Gal, and glucose oxidase, GOx, in the Fe-ZIF-90 provides an organized framework allowing the operation of a three-catalyst cascade, where the β-Gal-catalyzed oxidation of lactose yields glucose and galactose, and the resulting glucose is aerobically oxidized by GOx to gluconic acid and HO, followed by the Fe-ZIF-90-catalyzed HO oxidation of TMB to TMB˙. The coupled bienzyme/nanozyme cascade in the MOFs is 5-fold enhanced, as compared to a homogeneous mixture of the catalytic constituents. The enhanced catalytic activity of the enzyme cascades in the MOFs is attributed to the confined reaction framework, allowing product channeling across the multienzyme constituents and overcoming diffusion barriers. Moreover, the enzymes, acetylcholine esterase, AChE, and choline oxidase, ChOx, are encapsulated in the confined porous Fe-ZIF-90 particles. The catalytic cascade where the neurotransmitter acetylcholine is hydrolyzed by AChE followed by the stepwise ChOx-catalyzed oxidation of choline to betaine and HO, and the Fe-ZIF-90-catalyzed oxidation of TMB to colored TMB˙ by HO is demonstrated. The three-catalyst cascade is 5-fold enhanced as compared to the mixture of separated catalysts. The integrated three-catalyst AChE/ChOx/Fe-ZIF-90 particles are applied as colorimetric sensors detecting the neurotransmitter acetylcholine and probing AChE inhibitors. The novelty of the systems is reflected by the assembly of multienzyme catalytic Fe-ZIF-90 hybrids in confined environments as bioreactor frameworks driving effective biocatalytic cascades.
铁掺杂的ZIF-90（Fe-ZIF-90），一种金属有机框架材料（MOF），被合成并进行了表征。MOF颗粒通过催化3,3',5,5'-四甲基联苯胺（TMB）被HO氧化为TMB˙，展现出类过氧化物酶活性。将β-半乳糖苷酶（β-Gal）和葡萄糖氧化酶（GOx）这两种酶整合到Fe-ZIF-90中，提供了一个有组织的框架，使得三催化剂级联反应得以运行，其中β-Gal催化乳糖氧化生成葡萄糖和半乳糖，生成的葡萄糖被GOx有氧氧化为葡萄糖酸和HO，随后Fe-ZIF-90催化HO将TMB氧化为TMB˙。与催化成分的均相混合物相比，MOF中的双酶/纳米酶耦合级联反应增强了5倍。MOF中酶级联反应催化活性的增强归因于受限的反应框架，它允许产物在多种酶成分之间传递并克服扩散障碍。此外，乙酰胆碱酯酶（AChE）和胆碱氧化酶（ChOx）被封装在受限的多孔Fe-ZIF-90颗粒中。展示了催化级联反应，即神经递质乙酰胆碱被AChE水解，随后胆碱被ChOx逐步催化氧化为甜菜碱和HO，以及Fe-ZIF-90催化HO将TMB氧化为显色的TMB˙。与分离催化剂的混合物相比，三催化剂级联反应增强了5倍。集成的三催化剂AChE/ChOx/Fe-ZIF-90颗粒被用作比色传感器来检测神经递质乙酰胆碱并探测AChE抑制剂。这些系统的新颖之处体现在多酶催化的Fe-ZIF-90杂化物在受限环境中组装成生物反应器框架，驱动有效的生物催化级联反应。
