基于氧化酶电化学“布线”的L-α-甘油磷酸酯和L-乳酸电极。

L-alpha-glycerophosphate and L-lactate electrodes based on the electrochemical "wiring" of oxidases.

作者信息

Katakis I, Heller A

机构信息

University of Texas, Department of Chemical Engineering, Austin 78712.

出版信息

Anal Chem. 1992 May 1;64(9):1008-13. doi: 10.1021/ac00033a009.

DOI:10.1021/ac00033a009

PMID:1590584

Abstract

The title electrodes were constructed by coimmobilizing the respective FAD oxidases on solid electrode surfaces with a poly(vinyl pyridine) polymer which was N-derivatized with bromoethylamine and Os(bpy)2Cl2. The redox-polymer-enzyme hydrogels were cross-linked on the electrode surface using poly(ethylene glycol) diglycidyl ether. As in the case of glucose oxidase, the redox polymer acts as an electron relaying "wire" transferring electrons directly from the enzymes' FADH2 centers to the electrode. This transfer competes with the natural process of reoxidation of FADH2 by molecular oxygen. The variation of the response of these electrodes with the atmosphere (N2 or air), pH, and substrate concentration was determined. The pH profile of the electrocatalytic current differs from that of the activity of the free enzymes, exhibiting a broader maximum, shifted to higher pH values. The observed sensitivities and linear ranges are respectively 2 x 10(-2) A M-1 cm-2 and 2.7 mM for L-alpha-glycerophosphate, and 0.3 A M-1 cm-2 and 0.2 mM for L-lactate that may be compared to 2 x 10(-2) A M-1 cm-2 and 10 mM for glucose. The 0-90% response time for all electrodes is 1 s or less.

摘要

通过将各自的黄素腺嘌呤二核苷酸（FAD）氧化酶与用溴乙胺和二氯二（2,2'-联吡啶）锇（Os(bpy)₂Cl₂）进行N-衍生化的聚乙烯基吡啶聚合物共固定在固体电极表面来构建标题电极。使用聚乙二醇二缩水甘油醚在电极表面交联氧化还原聚合物-酶水凝胶。与葡萄糖氧化酶的情况一样，氧化还原聚合物充当电子传递“导线”，将电子直接从酶的FADH₂中心转移到电极。这种转移与FADH₂被分子氧再氧化的自然过程相互竞争。测定了这些电极的响应随气氛（N₂或空气）、pH和底物浓度的变化。电催化电流的pH曲线与游离酶活性的pH曲线不同，表现出更宽的最大值，且向更高的pH值偏移。观察到的灵敏度和线性范围对于L-α-甘油磷酸分别为2×10⁻² A M⁻¹ cm⁻²和2.7 mM，对于L-乳酸为0.3 A M⁻¹ cm⁻²和0.2 mM，而葡萄糖的分别为2×10⁻² A M⁻¹ cm⁻²和10 mM。所有电极的0 - 90%响应时间为1秒或更短。