Xanthine oxidase/laponite nanoparticles immobilized on glassy carbon electrode: Direct electron transfer and multielectrocatalysis
Xanthine oxidase/laponite nanoparticles immobilized on glassy carbon electrode: Direct electron transfer and multielectrocatalysis
复制标题
固定在玻碳电极上的黄嘌呤氧化酶/合成锂皂石纳米粒子：直接电子转移和多电催化
DOI：
10.1016/j.bios.2009.05.009
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发表时间：
2009-08-15
影响因子：
12.6
通讯作者：
Ding, Shou-Nian
中科院分区：
文献类型：
--
作者：
Shan, Dan;Wang, Yan-Na;Ding, Shou-Nian
在这项工作中，胶体锂皂石纳米粒子进一步扩展到第三代生物传感器的设计。首次研究了合成锂皂石纳米粒子固定化黄嘌呤氧化酶（XnOx）在玻碳电极上的直接电化学行为。XnOx/laponite薄膜修饰电极在约-0.370 V vs. SCE（pH 5）处仅显示出一对归因于XnOx-FAD辅因子的明确且可逆的循环伏安峰。XnOx-FAD/FADH（2）电对的形式电位在4.0-8.0范围内随pH的增加呈线性变化，斜率为-54.3mV pH（-1），表明电化学反应中存在双质子转移和双电子转移。更有趣的是，固定化的XnOx保持其生物活性良好，并显示出良好的电催化性能，无论是黄嘌呤的氧化和硝酸盐的还原。电催化响应显示出对黄嘌呤浓度的线性依赖性，范围为3.9 x 10（-8）至2.1 x 10（-5）M，基于S/N = 3，检测限为1.0 x 10（-8）M。(C)2009爱思唯尔有限公司版权所有。
In this work, colloidal laponite nanoparticles were further expanded into the design of the third-generation biosensor. Direct electrochemistry of the complex molybdoenzyme xanthine oxidase (XnOx) immobilized on glassy carbon electrode (GCE) by laponite nanoparticles was investigated for the first time. XnOx/laponite thin film modified electrode showed only one pair of well defined and reversible cyclic voltammetric peaks attributed to XnOx-FAD cofactor at about -0.370 V vs. SCE (pH 5). The formal potential of XnOx-FAD/FADH(2) couple varied linearly with the increase of pH in the range of 4.0-8.0 with a slope of -54.3 mV pH(-1), which indicated that two-proton transfer was accompanied with two-electron transfer in the electrochemical reaction. More interestingly, the immobilized XnOx retained its biological activity well and displayed an excellent electrocatalytic performance to both the oxidation of xanthine and the reduction of nitrate. The electrocatalytic response showed a linear dependence on the xanthine concentration ranging from 3.9 x 10(-8) to 2.1 x 10(-5) M with a detection limit of 1.0 x 10(-8) M based on S/N = 3. (C) 2009 Elsevier B.V. All rights reserved.