Minimizing Fouling at Hydrogenated Conical-Tip Carbon Electrodes during Dopamine Detection in Vivo

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• 作者：Shaneel Chandra ; Anthony D. Miller ; Avi Bendavid ; Philip J. Martin ; Danny K. Y. Wong
• 刊名：Analytical Chemistry
• 出版年：2014
• 出版时间：March 4, 2014
• 年：2014
• 卷：86
• 期：5
• 页码：2443-2450
• 全文大小：351K
• 年卷期：v.86,no.5(March 4, 2014)
• ISSN：1520-6882

文摘

In this paper, physically small conical-tip carbon electrodes (2鈥? 渭m diameter and 4 渭m axial length) were hydrogenated to develop a probe capable of withstanding fouling during dopamine detection in vivo. Upon hydrogenation, the resultant hydrophobic sp³ carbon surface deters adsorption of amphiphilic lipids, proteins, and peptides present in extracellular fluid and hence minimizes electrode fouling. These hydrogenated carbon electrodes showed a 35% decrease in sensitivity but little change in the limit of detection for dopamine over a 7-day incubation in a synthetic laboratory solution containing 1.0% (v/v) caproic acid (a lipid), 0.1% (w/v) bovine serum albumin and 0.01% (w/v) cytochrome C (both are proteins), and 0.002% (w/v) human fibrinopeptide B (a peptide). Subsequently, during dopamine detection in vivo, over 70% of the dopamine oxidation current remained after the first 30 min of a 60-min experiment, and at least 50% remained over the next half-period at the hydrogenated carbon electrodes. On the basis of these results, an initial average electrode surface fouling rate of 1.2% min^鈥? was estimated, which gradually declined to 0.7% min^鈥?. These results support minimal fouling at hydrogenated carbon electrodes applied to dopamine detection in vivo.