Beijing National Laboratory for Molecular Sciences, Key Laboratory of Analytical Chemistry for Living Biosystems, Institute of Chemistry, Chinese Academy of Sciences, Beijing 100190, P.R. China.
School of Chemical Sciences, University of Chinese Academy of Sciences, Beijing 100049, P.R. China.
Nanoscale. 2023 Sep 1;15(34):14055-14060. doi: 10.1039/d3nr03514j.
Enzyme immobilization on metal-organic frameworks (MOFs) has interested researchers in recent decades due to the outstanding characteristics of MOFs. However, despite some enzyme@MOF composites exhibiting better tolerance, stability and catalysis than free enzymes, boosting the catalytic performance of stimuli-responsive polymer-grafted MOFs composites remains a challenging task. Herein, a glucose oxidase (GOx)-horseradish peroxidase (HRP)@MOF (UiO-66-NH, U)@polymer composite with tunable catalytic ability was constructed by modification with thermo-responsive poly(-isopropylacrylamide) (PN) a surface-selective post-synthetic protocol. Temperature increases changed the PN-based soft armour from a "stretch" to a "coil" conformation on the MOF surface, resulting in the confinement effect and boosting the catalytic performance of the GOx-HRP@U@PN composites. Compared with its maximum catalytic reaction rate at 25 °C, the proposed composites showed 18-fold improvement in catalytic performance at 37 °C. Additionally, a colourimetric method for serum glucose analysis was developed using a GOx-HRP-based catalytic cascade reaction with a linear range from 0.1 to 2.0 mM and a low detection limit of 0.03 mM. Remarkably, the surface PN-shell-based soft armour proved to be the key factor for enhancing the catalytic performance of the as-designed composites. The co-immobilization of GOx-HRP onto the thermo-responsive U@PN surface provides a new approach for the development of highly sensitive colourimetric glucose sensing protocols.
在过去的几十年中，由于金属有机骨架（MOFs）的出色特性，酶固定在 MOFs 上引起了研究人员的兴趣。然而，尽管一些酶@MOF 复合材料表现出比游离酶更好的耐受性、稳定性和催化性能，但提高刺激响应聚合物接枝 MOFs 复合材料的催化性能仍然是一项具有挑战性的任务。在此，通过使用温度响应性聚（异丙基丙烯酰胺）（PN）对 UiO-66-NH （U）@聚合物复合材料进行表面选择性后合成修饰，构建了一种具有可调催化能力的葡萄糖氧化酶（GOx）-辣根过氧化物酶（HRP）@MOF（UiO-66-NH，U）@聚合物复合材料。温度升高会改变 MOF 表面上基于 PN 的软铠甲从“伸展”到“卷曲”的构象，从而产生约束效应并提高 GOx-HRP@U@PN 复合材料的催化性能。与 25°C 时的最大催化反应速率相比，所提出的复合材料在 37°C 时的催化性能提高了 18 倍。此外，还开发了一种基于 GOx-HRP 催化级联反应的血清葡萄糖分析比色法，线性范围为 0.1 至 2.0 mM，检测限低至 0.03 mM。值得注意的是，基于表面 PN 壳的软铠甲被证明是提高设计复合材料催化性能的关键因素。GOx-HRP 共固定在温度响应性 U@PN 表面上，为开发高灵敏度比色葡萄糖传感方案提供了一种新方法。
