The Glucose Effect on Direct Electrochemistry and Electron Transfer Reaction of Glucose Oxidase Entrapped in a Carbon Nanotube‐Polymer Matrix
The Glucose Effect on Direct Electrochemistry and Electron Transfer Reaction of Glucose Oxidase Entrapped in a Carbon Nanotube‐Polymer Matrix
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DOI：
10.1002/slct.202003536
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发表时间：
2020-10
期刊：
影响因子：
5.3
通讯作者：
Ziyu Yin;Zuowei Ji;Wendi Zhang;E. Taylor;Xin-ping Zeng;Jianjun Wei
中科院分区：
文献类型：
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作者：
Ziyu Yin;Zuowei Ji;Wendi Zhang;E. Taylor;Xin-ping Zeng;Jianjun Wei
在这项工作中，葡萄糖氧化酶（GOx）交联到单壁碳纳米管（SWCNTs）-聚（乙烯亚胺）（PEI）矩阵进行了研究，使用循环伏安法（CV）的直接电化学和动力学与葡萄糖的存在。结合的黄素辅因子，GOx的黄素腺嘌呤二核苷酸（FAD）的电化学被葡萄糖阻碍，并且在不存在葡萄糖的情况下恢复，而非特异性糖（例如，蔗糖）没有这种效果。当葡萄糖浓度增加时，CV中GOx的法拉第电流减小，而计算的GOx的电子转移（ET）速率常数（k 0）在70 mM葡萄糖浓度下与不存在葡萄糖的脱气电解质溶液中呈现单调递增的方式高达144%。 k 0和法拉第电流的变化与葡萄糖浓度的对数值呈很强的线性关系，直至20 mM。 这些结果表明，当暴露于葡萄糖时，截留的GOx在直接电化学中变得失活。进一步的机制分析表明，GOx的ET反应显示出与这些活性GOx位点的非遍历性的响应相关性。使用固定在基质中的纯FAD的对照实验未显示对葡萄糖添加的响应。
In this work, glucose oxidase (GOx) cross‐linking to a single‐wall carbon nanotubes (SWCNTs)‐poly(ethylenimine) (PEI) matrix is investigated using cyclic voltammetry (CV) for its direct electrochemistry and kinetics with presence of glucose. The electrochemistry of the bound flavin cofactor, flavin adenine dinucleotide (FAD) of the GOx, is impeded by glucose and recovered at absence of glucose, whereas a non‐specific sugar (e. g. sucrose) has no such effect. The Faradaic current of the GOx in CV decreases when the concentration of glucose increases, while the calculated electron transfer (ET) rate constant (k0) of the GOx presents a monotonic increment manner up to 144 % at 70 mM glucose concentration vs. absence of glucose in a deaerated electrolyte solution. Thek0and Faradaic current changes demonstrate a strong linear relationship to logarithmic value of glucose concentration up to 20 mM. These results suggest that the entrapped GOx, when exposing to glucose, becomes deactivated in the direct electrochemistry. Further mechanistic analysis suggests the ET reaction of GOx shows a responsive correlation to the non‐ergodicity of those active GOx sites. A control experiment using pure FAD immobilized in the matrix doesn't show responses to glucose addition.