Carbon microelectrodes with a renewable surface.
Carbon microelectrodes with a renewable surface.
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DOI：
10.1021/ac902753x
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发表时间：
2010-03-01
影响因子：
7.4
通讯作者：
Wightman RM
中科院分区：
文献类型：
--
作者：
Takmakov P;Zachek MK;Keithley RB;Walsh PL;Donley C;McCarty GS;Wightman RM
电极结垢降低了灵敏度，并且可以是电化学实验中的实质性限制。在这项工作中，我们描述了一个电化学过程，不断更新的碳微电极的表面使用周期性的三角形电压偏移到扩展的阳极电位在400 Vs−1的扫描速率。这种方法允许电化学活性表面的再生，并恢复因化学物质的不可逆吸附而降低的电极灵敏度。我们表明，在水溶液中反复伏安扫描到中等电位会导致碳的氧化蚀刻，从而不断更新的电化学活性表面。氧化蚀刻建立通过跟踪表面局部的氟原子与XPS，通过监测碳表面形貌的变化与原子力显微镜热解的光致抗蚀剂膜，也通过光学和电子显微镜。使用具有扩展阳极电位的波形显示出对邻苯二酚检测的灵敏度大幅增加。这种增强产生的邻苯二酚部分，可以保持与电极表面的恒定再生的吸附。我们还表明，应用程序的扩展波形可以恢复碳微电极的灵敏度减少不可逆吸附（电极结垢）的副产物从酪胺的电氧化和聚合。总的来说，这项工作带来了新的见解，影响碳电极的电化学过程的因素，并提供了一种简单的方法来消除或减少与许多电化学实验相关的污垢问题。
Electrode fouling decreases sensitivity and can be a substantial limitation in electrochemical experiments. In this work we describe an electrochemical procedure that constantly renews the surface of a carbon microelectrode using periodic triangle voltage excursions to an extended anodic potential at a scan rate of 400 Vs−1. This methodology allows for the regeneration of an electrochemically active surface and restores electrode sensitivity degraded by irreversible adsorption of chemical species. We show that repeated voltammetric sweeps to moderate potentials in aqueous solution causes oxidative etching of carbon thereby constantly renewing the electrochemically active surface. Oxidative etching was established by tracking surface-localized fluorine atoms with XPS, by monitoring changes in carbon surface morphology with AFM on pyrolyzed photoresist films, and also by optical and electron microscopy. The use of waveforms with extended anodic potentials showed substantial increases in sensitivity towards the detection of catechols. This enhancement arose from the adsorption of the catechol moiety that could be maintained with a constant regeneration of the electrode surface. We also demonstrate that application of the extended waveform could restore the sensitivity of carbon microelectrodes diminished by irreversible adsorption (electrode fouling) of byproducts resulting from the electrooxidation and polymerization of tyramine. Overall, this work brings new insight into the factors that affect electrochemical processes at carbon electrodes and provides a simple method to remove or reduce fouling problems associated with many electrochemical experiments.
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影响因子：
4.2
作者：
Heien, MLAV;Phillips, PEM;Wightman, RM
通讯作者：
Wightman, RM
影响因子：
3.9
作者：
Kim, J;Song, X;White, B
通讯作者：
White, B
影响因子：
3
作者：
KOVACH, PM;EWING, AG;WIGHTMAN, RM
通讯作者：
WIGHTMAN, RM
影响因子：
7.4
作者：
Bath, BD;Michael, DJ;Wightman, RM
通讯作者：
Wightman, RM
影响因子：
4.5
作者：
Kiema, GK;Aktay, M;McDermott, MT
通讯作者：
McDermott, MT