Optimal environment for glucose oxidase in perfluorosulfonated ionomer membranes: Improvement of first-generation biosensors
Optimal environment for glucose oxidase in perfluorosulfonated ionomer membranes: Improvement of first-generation biosensors
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DOI：
10.1021/ac0155409
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发表时间：
2002-04-01
影响因子：
7.4
通讯作者：
Wang, J
中科院分区：
文献类型：
--
作者：
Karyakin, AA;Kotel'nikova, EA;Wang, J
葡萄糖氧化酶（GOx）在Naflon膜上的最佳环境是使用基于非水固定路线的先进固定方案实现的。葡萄糖氧化酶暴露于有机溶剂含量高（85-95%）的水-有机混合物中，形成膜的聚电解质使酶稳定下来。这样一个最佳的环境导致最高的酶比活性在所得膜，如所需的最优使用昂贵的氧化酶。含有葡萄糖氧化酶和Naflon的铸造溶液在冰箱中完全稳定超过5天，提供几乎绝对的GOx-Nafion膜的再现性。将GOx-Nafion膜浇铸在普鲁士蓝修饰的玻璃碳圆盘电极上，制备了葡萄糖生物传感器。在FIA模式下工作的生物传感器允许检测到0.1 muM水平的葡萄糖，同时具有高灵敏度（0.05 A M-1 cm(-2)），仅比使用的过氧化氢传感器的灵敏度低10倍。与最近报道的基于类似H2O2传感器（过渡金属六氰高铁酸盐）的酶电极的比较表明，所提出的方法在所得生物传感器的灵敏度上显示出显着的（100倍）提高。结合普鲁士蓝过氧化氢传感器的诱人性能，所提出的固定化方案在灵敏度和检测限方面为第一代葡萄糖生物传感器提供了优越的性能。
An optimal environment for glucose oxidase (GOx) in Naflon membranes is achieved using an advanced immobilization protocol based on a nonaqueous immobilization route. Exposure of glucose oxidase to water-organic mixtures with a high (85-95%) content of the organic solvent resulted in stabilization of the enzyme by a membrane-forming polyelectrolyte. Such an optimal environment leads to the highest enzyme specific activity in the resulting membrane, as desired for optimal use of the expensive oxidases. Casting solution containing glucose oxidase and Naflon is completely stable over 5 days in a refrigerator, providing almost absolute reproducibility of GOx-Nafion membranes. A glucose biosensor was prepared by casting the GOx-Nafion membranes over Prussian Blue-modified glassy carbon disk electrodes. The biosensor operated in the FIA mode allows the detection of glucose down to the 0.1 muM level, along with high sensitivity (0.05 A M-1 cm(-2)), which is only 10 times lower than the sensitivity of the hydrogen peroxide transducer used. A comparison with the recently reported enzyme electrodes based on similar H2O2 transducers (transition metal hexacyanoferrates) shows that the proposed approach displays a dramatic (100-fold) improvement in sensitivity of the resulting biosensor. Combined with the attractive performance of a Prussian Blue-based hydrogen peroxide transducer, the proposed immobilization protocol provides a superior performance for first-generation glucose biosensors in term of sensitivity and detection limits.