School of Chemistry & Ryan Institute, National University of Ireland Galway, Galway, Ireland.
Anal Bioanal Chem. 2013 Apr;405(11):3807-12. doi: 10.1007/s00216-012-6628-9. Epub 2013 Jan 11.
Here, we report on a novel, versatile approach for the preparation of mediated enzyme electrodes, demonstrated using cross-linked films of glucose oxidase and a range of functionalised osmium complexes on graphite electrodes. Response of enzyme electrodes are optimised by evaluation of glucose response as a function of variation in ratios of Os(2,2'-bipyridine)2(4-aminomethyl pyridine)Cl redox mediator, polyallylamine support and glucose oxidase enzyme cross-linked using a di-epoxide reagent in films on graphite. Lowering of the redox potential required to mediate glucose oxidation is achieved by synthesis of complexes using (4,4'-dimethyl-2,2'-bipyridine) or (4,4'-dimethoxy-2,2'-bipyridine) as a ligand instead of (2,2'-bipyridine). Enzyme electrodes prepared using the complexes based on dimethoxy- or dimethyl-substituted bipyridines provide glucose oxidation current densities of 30 and 70 μA cm(-2) at 0.2 and 0.35 V applied potential compared to 120 μA cm(-2) at 0.45 V for the initial enzyme electrode, under pseudo-physiological conditions in 5 mM glucose, with stability of signals proving inadequate for long-term operation. Current output and stability may be improved by selection of alternate anchoring and cross-linking methodology, to provide enzyme electrodes capable for application to long-term glucose biosensors and anodes in enzymatic fuel cells.
在这里，我们报告了一种新颖的、通用的制备介体型酶电极的方法，该方法使用交联的葡萄糖氧化酶和一系列功能化的钌配合物在石墨电极上进行了演示。通过评估酶电极在葡萄糖响应作为Os(2,2'-联吡啶)2(4-氨甲基吡啶)Cl氧化还原介体、聚烯丙胺支持物和葡萄糖氧化酶的比例变化的函数中的葡萄糖响应来优化酶电极的响应，使用二环氧试剂在石墨上的薄膜中交联。通过使用（4,4'-二甲氧基-2,2'-联吡啶）或（4,4'-二甲基-2,2'-联吡啶）代替（2,2'-联吡啶）合成配合物，可以降低介导葡萄糖氧化所需的氧化还原电位。与初始酶电极在 0.45 V 施加电位下 120 μA cm(-2)相比，使用基于二甲氧基或二甲基取代联吡啶的配合物制备的酶电极在 5 mM 葡萄糖的假生理条件下，在 0.2 和 0.35 V 施加电位下提供 30 和 70 μA cm(-2)的葡萄糖氧化电流密度，信号的稳定性不足以进行长期操作。通过选择替代的固定化和交联方法，可以提高电流输出和稳定性，从而提供可应用于长期葡萄糖生物传感器和酶燃料电池阳极的酶电极。
