Electronically Type-Sorted Carbon Nanotube-Based Electrochemical Biosensors with Glucose Oxidase and Dehydrogenase
Electronically Type-Sorted Carbon Nanotube-Based Electrochemical Biosensors with Glucose Oxidase and Dehydrogenase
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DOI：
10.1021/am506758u
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发表时间：
2015-01-14
影响因子：
9.5
通讯作者：
Nowaki, Kohei
中科院分区：
文献类型：
--
作者：
Muguruma, Hitoshi;Hoshino, Tatsuya;Nowaki, Kohei
介绍了一种用于水介质中的电化学酶生物传感器，它具有电子型分类(金属和半导体)单壁碳纳米管(SWNTs)。本研究探讨了单壁碳纳米管的电子类型如何影响酶生物传感器的安培响应。为了进行清晰的评价，采用了一种简单的基于等离子体聚合纳米薄膜(PPF)的逐层工艺，因为PPF是一种不活跃的基质，可以形成由单壁碳纳米管和酶组成的明确的纳米结构。对于有葡萄糖氧化酶(GOx)酶的生物传感器，金属SWNT-Gox电极的响应比半导体SWNT-Gox电极的响应大2倍。相反，在无氧条件下，半导体SWNT-GOx电极的响应保持不变，而金属SWNT-GOx电极的响应显著降低。这表明半导体SWNT-GOx电极发生了直接的电子转移，而金属SWNT-GOx电极是由酶反应引起的过氧化氢途径主导的。对于含有葡萄糖脱氢酶的生物传感器，半导体SWNT-GDH电极的响应比金属SWNT-GDH电极的响应大4倍。电化学阻抗谱分析表明，半导体碳纳米管网络的电子转移阻力小于金属碳纳米管网络。因此，半导体单壁碳纳米管比金属单壁碳纳米管更适合作为电化学酶生物传感器的检测机理。本研究为利用分选的单壁碳纳米管和各种酶的电化学生物传感器的发展做出了有价值的贡献。
An electrochemical enzyme biosensor with electronically type-sorted (metallic and semiconducting) single-walled carbon nanotubes (SWNTs) for use in aqueous media is presented. This research investigates how the electronic types of SWNTs influence the amperometric response of enzyme biosensors. To conduct a clear evaluation, a simple layer-by-layer process based on a plasma-polymerized nano thin film (PPF) was adopted because a PPF is an inactive matrix that can form a well-defined nanostructure composed of SWNTs and enzyme. For a biosensor with the glucose oxidase (GOx) enzyme in the presence of oxygen, the response of a metallic SWNT-GOx electrode was 2 times larger than that of a semiconducting SWNT-GOx electrode. In contrast, in the absence of oxygen, the response of the semiconducting SWNT-GOx electrode was retained, whereas that of the metallic SWNT-GOx electrode was significantly reduced. This indicates that direct electron transfer occurred with the semiconducting SWNT-GOx electrode, whereas the metallic SWNT-GOx electrode was dominated by a hydrogen peroxide pathway caused by an enzymatic reaction. For a biosensor with the glucose dehydrogenase (GDH; oxygen-independent catalysis) enzyme, the response of the semiconducting SWNT-GDH electrode was 4 times larger than that of the metallic SWNT-GDH electrode. Electrochemical impedance spectroscopy was used to show that the semiconducting SWNT network has less resistance for electron transfer than the metallic SWNT network. Therefore, it was concluded that semiconducting SWNTs are more suitable than metallic SWNTs for electrochemical enzyme biosensors in terms of direct electron transfer as a detection mechanism. This study makes a valuable contribution toward the development of electrochemical biosensors that employ sorted SWNTs and various enzymes.