电化学生物传感器 2011

A glucose biosensor based on chitosan-Prussian blue-multiwall carbon nanotubes-hollow PtCo nanochains formed by one-step electrodeposition.

Colloids and surfaces. B, Biointerfaces Che X, Yuan R, Chai Y, Li J, Song Z, Li W, Zhong X
阅读原文 PDF DOI PubMed

组成图示

A glucose biosensor based on chitosan... 传感器构成示意图

点击图片查看大图 · 依据论文自动绘制

传感器类型

电化学生物传感器

检测对象

葡萄糖(glucose,D-葡萄糖);样品基质:0.025 M PBS(pH 6.0)加标溶液

检测原理

在优化条件下,传感器于-0.1 V(vs. SCE)进行安培检测。葡萄糖扩散至电极表面,被固定化葡萄糖氧化酶(GOD)催化氧化,生成葡萄糖内酯和过氧化氢(H2O2)。普鲁士蓝(PB)作为氧化还原介导剂,在低电位下与H2O2发生氧化还原循环:H2O2将普鲁士白氧化为PB,PB随后在电极表面被还原为普鲁士白并释放电子。该循环使H2O2的氧化还原电位显著降低,避免抗坏血酸、尿酸等干扰。多壁碳纳米管(MWNTs)和中空PtCo纳米链(H-PtCo)形成三维多孔导电网络,提高电子传递速率、酶负载量和葡萄糖氧化催化活性。因此,稳态安培电流随葡萄糖浓度增加而增大,在1.5 μM–1.12 mM范围内线性响应。

检测灵敏度

LOD: 0.47 μM (S/N = 3);线性范围: 1.5 μM–1.12 mM;灵敏度: 23.4 μA mM−1 cm−2;R^2 = 0.9989

效应效果

该传感器在-0.1 V下对葡萄糖响应迅速,达到95%稳态电流时间小于5 s(表1列为4 s)。对多巴胺、甘氨酸、L-半胱氨酸、抗坏血酸等干扰物无明显电流变化,抗干扰能力强。连续5次测量RSD为3.3%,5个电极间RSD为4.8%。4 ℃保存3天内响应无明显变化,保存2周和1个月后分别保留92.1%和85.3%初始灵敏度。标准添加回收率为93.8%–103%(表2中为96.5%–104.1%)。其灵敏度23.4 μA mM−1 cm−2高于文献报道的1.89、8.017和18 μA mM−1 cm−2,线性范围、检出限和响应时间优于多种已报道葡萄糖传感器,适用于血糖及相关样品中葡萄糖的快速检测。

传感器的构成

  • 基底/换能器电极:金电极(Au),经抛光和化学清洗,提供导电基底并作为电化学换能器。
  • 复合修饰层:壳聚糖(CS)–普鲁士蓝(PB)–多壁碳纳米管(MWNTs)–中空PtCo纳米链(H-PtCo)一步电沉积膜;CS成膜并防止PB泄漏,PB作为氧化还原介导剂催化H2O2还原,MWNTs提高导电性和比表面积,H-PtCo增强电子传递与葡萄糖氧化催化。
  • 识别元件:葡萄糖氧化酶(GOD),固定于复合膜上,催化葡萄糖氧化生成H2O2。
  • 封闭/稳定层:Nafion,涂覆于GOD层外,防止酶流失、提供生物相容微环境并提高抗干扰能力。

中文摘要

本文报道了一种简单的一步电沉积方法,在金电极表面构筑壳聚糖–普鲁士蓝–多壁碳纳米管–中空PtCo纳米链(CS–PB–MWNTs–H-PtCo)复合膜,随后在其上固定葡萄糖氧化酶(GOD)和Nafion,制备葡萄糖生物传感器。采用傅里叶变换红外光谱(FTIR)、扫描电子显微镜(SEM)以及循环伏安(CV)和电化学阻抗谱(EIS)等电化学技术,对复合膜的形貌和电化学行为进行了表征,并在优化条件下通过计时电流法评价传感器性能。该传感器对葡萄糖在1.5 μM至1.12 mM范围内呈线性响应,检出限为0.47 μM(S/N=3),灵敏度为23.4 μA mM−1 cm−2,响应迅速,表观米氏常数KappM为1.89 mM。此外,该传感器还表现出较强的抗干扰能力、良好的稳定性和重现性。

英文摘要

In this paper, a simple one-step electrodeposition method is described to fabricate chitosan-Prussian blue-multiwall carbon nanotubes-hollow PtCo nanochains (CS-PB-MWNTs-H-PtCo) film onto the gold electrode surface, then glucose oxidase (GOD) and Nafion were modified onto the film subsequently to fabricate a glucose biosensor. The morphologies and electrochemistry of the composite were investigated by using Fourier transform infrared (FTIR) spectrometry, scanning electron microscopy (SEM) and electrochemical techniques including cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS), respectively. The performances of the biosensor have been investigated by chronoamperometry method under the optimized conditions. This biosensor showed a linear response to glucose range from 1.5 μM to 1.12 mM with a detection limit of 0.47 μM (S/N=3), a high sensitivity of 23.4 μA mM(-1) cm(-2), and a fast response time. The apparent Michaelis-Menten constant (K(M)(app)) was 1.89 mM. In addition, the biosensor also exhibited strong anti-interference ability, excellent stability and good reproducibility.