In biosensing analysis, the activity of enzyme systems is limited by their fragility, and substrates catalyzed by monoenzymes tend to undergo spontaneous decomposition during ineffective mass transfer processes. In this study, we propose a novel strategy to encapsulate the glucose oxidase and horseradish peroxidase (GOx&HRP) cascade catalytic system within the hydrophilic zeolite imidazole framework ZIF-90. By leveraging the specific pore structure of ZIF-90, we effectively immobilized GOx and HRP molecules in their three-dimensional conformations, which improved the catalytic activity of the encapsulated enzymes compared with that of free GOx and HRP in various harsh environments. Additionally, our strategy reduced the occurrence of ineffective mass transfer and enhanced the sensitivity of the biosensor through an enzyme cascade system. When this biosensor was applied to serum samples containing complex biological matrices, the degradation of GOx&HRP by various proteases and the surface adsorption of diverse biomolecules were effectively prevented, thereby generating stable and reliable signals of glucose levels. The sensor shows remarkable sensitivity and selectivity for determining glucose concentrations ranging from 0 to 2.5 μg ml⁻¹, with a detection limit as low as 0.034 μg ml⁻¹. Furthermore, we developed a paper-based colorimetric sensor utilizing GOx&HRP@ZIF-90 integrated with a smartphone platform for the visual detection of blood glucose.

中文翻译：

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通过一步固定化目视检测葡萄糖，提高金属-有机框架的双酶级联生物催化效率和稳定性


在生物传感分析中，酶系统的活性受其脆性的限制，由单酶催化的底物在无效的传质过程中往往会自发分解。在这项研究中，我们提出了一种新的策略，将葡萄糖氧化酶和辣根过氧化物酶 （GOx&HRP） 级联催化系统封装在亲水性沸石咪唑框架 ZIF-90 中。通过利用 ZIF-90 的特定孔结构，我们有效地将 GOx 和 HRP 分子固定在其三维构象中，与游离 GOx 和 HRP 相比，在各种恶劣环境中，包封酶的催化活性更高。此外，我们的策略减少了无效传质的发生，并通过酶级联系统提高了生物传感器的灵敏度。当该生物传感器应用于含有复杂生物基质的血清样品时，有效阻止了各种蛋白酶对 GOx&HRP 的降解和多种生物分子的表面吸附，从而产生稳定可靠的葡萄糖水平信号。该传感器在测定 0 至 2.5 μg ^ml-1 的葡萄糖浓度方面表现出卓越的灵敏度和选择性，检测限低至 0.034 μg ^ml-1。此外，我们开发了一种基于纸张的比色传感器，利用 GOx&HRP@ZIF-90 与智能手机平台集成，用于视觉检测血糖。