A pyruvate oxidase electrode based on an electrochemically deposited redox polymer
A pyruvate oxidase electrode based on an electrochemically deposited redox polymer
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DOI：
10.1002/(sici)1521-4109(199912)11:18
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发表时间：
1999-12-01
期刊：
影响因子：
3
通讯作者：
Scheller, FW
中科院分区：
文献类型：
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作者：
Gajovic, N;Habermüller, K;Scheller, FW
A.氧化还原聚合物修饰的多层膜生物传感器用于无氧样品中丙酮酸和磷酸的测定。这种新型的高导电性氧化还原聚合物是通过Os（bipy）（2）pyCl修饰的吡咯单体（6 × 10（-3）mol L-1）和噻吩（1 × 10（-3）mol L-1）在镀铂的玻璃碳电极上恒电位共聚（+1.4V vs. Ag/AgCl）而制备的。具有增加的活性表面积的氧化还原聚合物涂覆的铂黑层允许作为生物识别元件的丙酮酸氧化酶的吸附和从酶结合的FAD基团到电极的有效电子转移。在磷酸盐存在下，丙酮酸在氧-氟溶液中于阳极电位（350-500 mV）下测定，线性范围为0.02 × 10 ~（-3）~ 0.3 × 10 ~（-3）mol·L ~（-1）。灵敏度可达0.2Acm（-2）mol（-1）L。在丙酮酸作为共底物的情况下，在0.02 x 10（-3）和0.5 x 10（-3）mol L-1之间以类似方式测定磷酸盐。10天后传感器的灵敏度下降到约12%。由于抗坏血酸的干扰，由于所使用的Os（bipy）（2）pyCl-基团的高形式电位，可能是一个问题，在真实的样品中，吸附的酶的覆盖率的聚阳离子聚吡咯的尺寸排阻层进行了研究。与以前的利用丙酮酸氧化酶的酶电极相比，新方法提供了前所未有的高灵敏度，O-2-和硫胺二磷酸独立的操作，并提出了一个很大的一步电化学丙酮酸在体内测定。
A. redox polymer-modified, multilayer biosensor for the determination of pyruvate and phosphate in oxygen-free samples has been developed. The new, highly conductive redox polymer was produced by potentiostatic copolymerization (+1.4V vs. Ag/AgCl) of Os(bipy)(2)pyCl-modified pyrrole monomer (6 x 10(-3) mol L-1) and thiophene (1 x 10(-3) mol L-1) on top of a platinized glassy-carbon electrode. The redox polymer-coated platinum black layer with increased active surface area permitted the adsorption of pyruvate oxidase as the biological recognition element and efficient electron transfer from enzyme-bound FAD-groups to the electrode. Pyruvate was detected at anodic potentials (350-500 mV) in oxygen-foe solution in the presence of phosphate as the cosubstrate with a linear range from 0.02 x 10(-3) to 0.3 X 10(-3) mol L-1. A sensitivity as high as 0.2 A cm(-2) mol(-1) L was obtained. Phosphate was measured similarly between 0.02 x 10(-3) and 0.5 x 10(-3) mol L-1 in the presence of pyruvate as co-substrate. The sensitivity of the sensor dropped to about 12 % after 10 days. Since interference by ascorbate, due to the high formal potential of the used Os(bipy)(2)pyCl-group, could be a problem in real samples, coverage of the adsorbed enzyme by a polycationic size exclusion layer of polypyrrole was investigated. Compared to former enzyme electrodes utilizing pyruvate oxidase, the new approach offered an unprecedentedly high sensitivity, O-2- and thiamindiphosphate-independent operation and presented a large step towards electrochemical pyruvate determination in vivo.