On-Line Electrochemical Sensor for Selective Continuous Measurement of Acetylcholine in Cultured Brain Tissue
详细信息 查看全文
- 作者：Osamu Niwa ; Tsutomu Horiuchi ; Ryoji Kurita ; and Keiichi Torimitsu
- 刊名：Analytical Chemistry
- 出版年：1998
- 出版时间：March 15, 1998
- 年：1998
- 卷：70
- 期：6
- 页码：1126 - 1132
- 全文大小：106K
- 年卷期：v.70,no.6(March 15, 1998)
- ISSN：1520-6882
文摘
An on-line acetylcholine (ACh) sensor was developed inorder to determine extracellular ACh concentrationswithout interference from choline (Ch). The sensor iscomposed of a small-volume enzymatic prereactor (22-
L inner volume) in which choline oxidase and catalaseare immobilized in series. Carbon electrodes weremodified with an acetylcholine esterase (AChE), choline oxidase (ChOx), and osmium poly(vinylpyridine)-based redox polymer containing horseradish peroxidase (Os-gel-HRP). The sensor sensitivity was 43.7 nA/M(±0.15,n = 3) for ACh under optimized conditions. Almostnoresponse was seen when 100 M Ch was continuouslyinjected. The detection limit for ACh with the sensorwascomparable to that obtained using liquid chromatographywith electrochemical detection combined with an enzymatic reactor. The electrical stimulation of culturedrathippocampal tissue resulted in an extracellular AChincrease of 20 nM (±11 nM, n = 3). This increasewasobserved continuously with our online sensor combinedwith a microcapillary sampling probe located very closeto the tissue. The continuous measurement of ACh andCh using a split disk carbon film dual electrode in whichone electrode surface was modified with ChOx/Os-gel-HRP and the other with AChE-ChOx/Os-gel-HRP bilayerfilm was also demonstrated to improve the response timeby eliminating the prereactor.
L inner volume) in which choline oxidase and catalaseare immobilized in series. Carbon electrodes weremodified with an acetylcholine esterase (AChE), choline oxidase (ChOx), and osmium poly(vinylpyridine)-based redox polymer containing horseradish peroxidase (Os-gel-HRP). The sensor sensitivity was 43.7 nA/M(±0.15,n = 3) for ACh under optimized conditions. Almostnoresponse was seen when 100 M Ch was continuouslyinjected. The detection limit for ACh with the sensorwascomparable to that obtained using liquid chromatographywith electrochemical detection combined with an enzymatic reactor. The electrical stimulation of culturedrathippocampal tissue resulted in an extracellular AChincrease of 20 nM (±11 nM, n = 3). This increasewasobserved continuously with our online sensor combinedwith a microcapillary sampling probe located very closeto the tissue. The continuous measurement of ACh andCh using a split disk carbon film dual electrode in whichone electrode surface was modified with ChOx/Os-gel-HRP and the other with AChE-ChOx/Os-gel-HRP bilayerfilm was also demonstrated to improve the response timeby eliminating the prereactor.