电化学生物传感器 2012

A high-sensitive and fast-fabricated glucose biosensor based on Prussian blue/topological insulator Bi2Se3 hybrid film.

Biosensors & bioelectronics Wu S, Liu G, Li P, Liu H, Xu H
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组成图示

A high-sensitive and fast-fabricated ... 传感器构成示意图

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传感器类型

电化学生物传感器

检测对象

葡萄糖(Glucose);样品基质:人血清(human serum)、磷酸盐缓冲液(PBS)

检测原理

该传感器采用酶促-电催化级联机制。壳聚糖固定的葡萄糖氧化酶(GOD)特异性催化葡萄糖氧化,生成过氧化氢(H2O2);普鲁士蓝(PB)作为人工过氧化物酶,在约0.00 V低过电位下催化H2O2还原为水,PB自身在普鲁士蓝/普鲁士白之间可逆电子转移。拓扑绝缘体Bi2Se3具有导电表面态,与PB共电沉积形成更细小、致密的杂化膜,提高电子转移速率并增强中性/弱碱性稳定性。葡萄糖浓度越高,酶产生H2O2越多,PB催化还原产生的安培电流越大,从而实现定量检测。

检测灵敏度

LOD: 3.8 mM;线性范围: 0.01–11.02 mM;灵敏度: 24.55 mA mM^-1 cm^-2;R^2 = 0.9940

效应效果

该传感器响应快,95%稳态响应时间小于3 s;对0.5 mM葡萄糖连续7次测定RSD为2.37%。在0.20 mM尿酸、多巴胺、抗坏血酸、L-组氨酸、L-半胱氨酸和L-胱氨酸存在下无明显干扰,抗干扰性好。4 ℃干燥保存两个月后仍保持90%初始响应;PB/Bi2Se3膜连续30次检测50 mM H2O2后响应保持85%以上。人血清样品无需预处理,结果与葡萄糖脱氢酶电极临床法一致,0.05水平无显著差异。制备时间约1 h,作者认为可替代传统血糖电极用于糖尿病监测。

传感器的构成

  • 基底/换能器电极:玻璃碳电极(GCE,直径3 mm),经抛光清洗后作为工作电极,承载修饰膜并传导电子。
  • 纳米材料修饰层:普鲁士蓝/拓扑绝缘体Bi2Se3杂化膜(PB/Bi2Se3),由Bi(NO3)3·5H2O、SeO2、K3Fe(CN)6、FeCl3等共电沉积形成,PB纳米颗粒催化H2O2还原,Bi2Se3使PB粒径更小、膜更致密并增强pH稳定性。
  • 识别元件:葡萄糖氧化酶(GOD),催化葡萄糖氧化生成H2O2,实现特异性识别。
  • 固定层:壳聚糖(CS)膜,以0.5% CS乙酸溶液配制GOD-CS滴涂成膜,固定GOD并提高生物相容性。
  • 信号转换/催化层:普鲁士蓝(PB)作为人工过氧化物酶,在0.00 V附近催化H2O2还原为H2O,产生与葡萄糖浓度相关的还原电流。
  • 支持电解质:0.025 M磷酸盐缓冲液(PBS,KH2PO4/K2HPO4,pH 6.86)含0.1 M KCl,提供离子导电、稳定酶活性和PB电催化环境。
  • 检测读出:三电极电化学工作站(LK2005),以饱和甘汞电极为参比、铂丝为对电极,在0.00 V进行安培检测。

中文摘要

通过共电沉积技术制备了一种新型且可快速制备的普鲁士蓝(PB)/拓扑绝缘体Bi2Se3杂化膜。利用拓扑绝缘体具有奇异金属表面态和体绝缘隙的优势,杂化膜中的PB纳米颗粒尺寸更小、结构更致密,即使在pH 8.0的碱性溶液中也表现出优异的pH稳定性。基于Laviron理论,PB/Bi2Se3杂化膜修饰电极的电子转移速率常数计算为4.05±0.49 s^-1,该值较大,有利于构建高灵敏生物传感器。随后将葡萄糖氧化酶(GOD)固定于杂化膜上,构建了安培葡萄糖生物传感器。在最优条件下,获得了跨越3个数量级的葡萄糖宽线性范围(1.0×10^-5–1.1×10^-2 M),灵敏度为24.55 mA mM^-1 cm^-2。以信噪比为3估计,检出限为3.8 mM。所得传感器用于检测人血清样品中的血糖,无需任何预处理,结果与临床检测基本一致。

英文摘要

A novel and fast-fabricated Prussian blue (PB)/topological insulator Bi(2)Se(3) hybrid film has been prepared by coelectrodeposition technique. Taking advantages of topological insulator in possessing exotic metallic surface states with bulk insulating gap, Prussian blue nanoparticles in the hybrid film have smaller size as well as more compact structure, showing excellent pH stability even in the alkalescent solution of pH 8.0. Based on the Laviron theory, the electron transfer rate constant of PB/Bi(2)Se(3) hybrid film modified electrode was calculated to be 4.05 ± 0.49 s(-1), a relatively big value which may be in favor of establishing a high-sensitive biosensor. An amperometric glucose biosensor was then fabricated by immobilizing glucose oxidase (GOD) on the hybrid film. Under the optimal conditions, a wide linear range extending over 3 orders of magnitude of glucose concentrations (1.0 × 10(-5)-1.1 × 10(-2)M) was obtained with a high sensitivity of 24.55 μA mM(-1) cm(-2). The detection limit was estimated for 3.8 μM defined from a signal/noise of 3. Furthermore, the resulting biosensor was applied to detect the blood sugar in human serum samples without any pretreatment, and the results were comparatively in agreement with the clinical assay.