A self-powered photoelectrochemical glucose biosensor based on supercapacitor Co3O4-CNT hybrid on TiO2
A self-powered photoelectrochemical glucose biosensor based on supercapacitor Co3O4-CNT hybrid on TiO2
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DOI：
10.1016/j.bios.2018.07.049
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发表时间：
2018-11-15
影响因子：
12.6
通讯作者：
Ozacar, Mahmut
中科院分区：
文献类型：
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作者：
Cakiroglu, Bekir;Ozacar, Mahmut
在本研究中，将超级电容器碳纳米管（CNT）和Co3O4沉积在锐钛矿型TiO2涂层的ITO电极上，构建了光电化学（PEC）生物传感器。本文采用带隙约为2.07 eV的超级电容器Co3O4作为半导体材料，并通过在电极材料中引入碳纳米管改善了PEC系统的超级电容器性能。此外，还首次构建了工作在0 V电压下的自赋能葡萄糖生物传感器。此外，在p-n结形成后，Co3O4被呈现为电子接受材料，这与它在光催化系统中的通常用途不同。采用co3o4 -碳纳米管-锐钛矿型TiO2半导体杂化物减少了出射电子的复合，增加了可见光吸收。在酶固定化之前，碳纳米管电极材料通过pi-pi相互作用被1-芘硼酸修饰。通过硼酸部分和GOx的碳水化合物部分之间的共价酯化进行酶固定化。酶固定化方式使FAD与电极材料紧密接触，酶促反应后形成的电子给体FADH(2)通过CNT与H2O2一起将电子给予光生Co3O4的空穴，增强光电流。所制备的PEC生物传感器具有良好的重复性和良好的稳定性，线性测量范围为0-4 mM，灵敏度为0.3 μ a mM(-1) cm(-2)，检出限为0.16 μ m。因此，首次将PEC与Co3O4的超级电容器特性相结合，构建了自供电生物传感器，并将PEC材料的应用扩展到其他分析物的光电检测中。超级电容器材料在直接电子转移电位范围内导致了高电流，这一现象意味着PEC电极也可以用于生物燃料电池以获得高功率。
In this study, a photoelectrochemical (PEC) biosensor was constructed by depositing supercapacitor carbon nanotubes (CNT) and Co3O4 onto the anatase TiO2 coated ITO electrodes. Herein, supercapacitor Co3O4 was employed as a semiconductor with a band gap of similar to 2.07 eV, and the supercapacitor behavior of the PEC system was improved by introducing CNT into the electrode material. Furthermore, a self-empowering glucose biosensor operating at 0 V was constructed for the first time. Also, upon the formation of p-n junction, Co3O4 was rendered electron accepting material, unlike its usual use in photocatalytic systems. Co3O4-CNT-anatase TiO2 semiconductor hybrid was used to reduce recombination of exited electrons, and increasing the visible light absorption. Prior to enzyme immobilization, CNT containing electrode material was modified with 1-pyrene boronic acid via pi-pi interactions. The enzyme immobilization was carried out through covalent esterification between the boronic acid moiety and the carbohydrate part of GOx. Enzyme immobilization way enabled the close contact between FAD and electrode material, and the electron donor FADH(2) forming after the enzymatic reaction can give electrons to the photogenerated holes of Co3O4 through CNT along with H2O2 by enhancing the photocurrent. The obtained PEC biosensor demonstrated acceptable reproducibility and decent stability with a linear measurement range of 0-4 mM, a sensitivity of 0.3 mu A mM(-1) cm(-2), and lower detection limit of 0.16 mu M. Thus, a self-powered biosensor was constructed by combining the PEC, and supercapacitor behavior of Co3O4 for the first time, and the utilization of the present PEC material can be extended to the other analytes detection through photoelectrochemistry. The supercapacitor materials led to the high current at direct electron transfer potential range, and this phenomenon implies that the PEC electrode can also be used in biofuel cells to obtain high power.