Enhanced measurement stability and selectivity for choline and acetylcholine by capillary electrophoresis with electrochemical detection at a covalently linked enzyme-modified electrode
Enhanced measurement stability and selectivity for choline and acetylcholine by capillary electrophoresis with electrochemical detection at a covalently linked enzyme-modified electrode
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DOI：
10.1021/ac020286l
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发表时间：
2002-10-15
影响因子：
7.4
通讯作者：
Hudson, RA
中科院分区：
文献类型：
--
作者：
Inoue, T;Kirchhoff, JR;Hudson, RA
开发了酶修饰微电极，用于通过毛细管电泳分离后对乙酰胆碱和胆碱进行间接电流检测。首先将单体的聚吡咯和聚酪胺依次电沉积在200μm的铂电极上来制备电极。聚合物双层通过与戊二醛反应，为乙酰胆碱酯酶 (AChE) 和胆碱氧化酶 (ChO) 的共价偶联提供增强的选择性和侧氨基。然后使用 AChE/ChO 修饰电极作为柱端检测器来测定乙酰胆碱以及含有或不含内标丁酰胆碱的胆碱。在连续使用 2 天期间观察到出色的操作稳定性，乙酰胆碱和胆碱的检测限均为 2 muM 或 50 fmol。与裸铂电极相比，多巴胺、儿茶酚和去甲肾上腺素等潜在干扰的响应显着降低。通过监测突触体对胆碱的摄取证明了这种方法的实用性。
Enzyme-modified microelectrodes were developed for the indirect amperometric detection of acetylcholine and choline following separation by capillary electrophoresis. Electrodes were prepared by first sequentially electrodepositing polypyrrole and polytyramine from the monomers on a 200-mum platinum electrode. The polymer bilayer provides enhanced selectivity and pendant amino groups for covalent coupling of acetylcholinesterase (AChE) and choline oxidase (ChO) by their reaction with glutaraldehyde. The AChE/ChO-modified electrode was then employed as an end-column detector to determine acetylcholine and choline with and without the internal standard butyrylcholine. Excellent operational stability during 2 days of continuous use was observed, with detection limits of 2 muM or 50 fmol for both acetylcholine and choline. The response from potential interferences, such as dopamine, catechol, and norepinephrine, were significantly reduced in comparison to a bare platinum electrode. The utility of this approach was demonstrated by monitoring the uptake of choline into synaptosomes.