An acetylcholinesterase biosensor based on platinum nanoparticles-carboxylic graphene-nafion-modified electrode for detection of pesticides

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• 作者：Long Yang ; Guangcan Wang ; ^{wangc166163@sina.com} ; Yongjun Liu
• 关键词：Carboxylic graphene ; Platinum nanoparticles ; Acetylcholinesterase ; Amperometric biosensor ; Stability
• 刊名：Analytical Biochemistry
• 出版年：2013
• 出版时间：15 June, 2013
• 年：2013
• 卷：437
• 期：2
• 页码：144-149
• 全文大小：742 K

文摘

A sensitive amperometric acetylcholinesterase (AChE) biosensor based on platinum nanoparticles (Pt NPs), carboxylic graphene (CGR), and nafion (NF)-modified glassy carbon electrode (GCE) has been developed. The Pt NPs-CGR-NF nanocomposites with excellent conductivity, catalysis, and biocompatibility offered an extremely hydrophilic surface for AChE adhesion. Chitosan (CS) was used as cross-linker to immobilize the AChE on Pt-CGR-NF-modified GCE. NF was used as a protective membrane of the AChE biosensors. The AChE biosensor showed favorable affinity to acetylthiocholine chloride (ATCl) and could catalyze the hydrolysis of ATCl with an apparent Michaelis-Menten constant value of 148 ¦ÌM. Under optimum conditions, the biosensor detected methyl parathion in the linear range from 1.0 ¡Á 10^?13 to 1 ¡Á 10^?10 M and from 1.0 ¡Á 10^?10 to 1 ¡Á 10^?8 M with a detection limit of 5 ¡Á 10^?14 M and detected carbofuran in the linear range from 1.0 ¡Á 10^?12 to 1 ¡Á 10^?10 M and from 1.0 ¡Á 10^?10 to 1 ¡Á 10^?8 M with a detection limit of 5 ¡Á 10^?13 M. The biosensor exhibited good sensitivity, acceptable stability, and reproducibility, thus providing a promising tool for analysis of enzyme inhibitors.