Department of Chemistry, University of Virginia , Charlottesville, Virginia 22904, United States.
Center for Nanophase Materials Sciences, Oak Ridge National Laboratory , 1 Bethel Valley Road, Oak Ridge, Tennessee 37831, United States.
Anal Chem. 2017 May 16;89(10):5605-5611. doi: 10.1021/acs.analchem.7b00785. Epub 2017 Apr 28.
Carbon nanotube (CNT) based microelectrodes exhibit rapid and selective detection of neurotransmitters. While different fabrication strategies and geometries of CNT microelectrodes have been characterized, relatively little research has investigated ways to selectively enhance their electrochemical properties. In this work, we introduce two simple, reproducible, low-cost, and efficient surface modification methods for carbon nanotube yarn microelectrodes (CNTYMEs): O plasma etching and antistatic gun treatment. O plasma etching was performed by a microwave plasma system with oxygen gas flow and the optimized time for treatment was 1 min. The antistatic gun treatment flows ions by the electrode surface; two triggers of the antistatic gun was the optimized number on the CNTYME surface. Current for dopamine at CNTYMEs increased 3-fold after O plasma etching and 4-fold after antistatic gun treatment. When the two treatments were combined, the current increased 12-fold, showing the two effects are due to independent mechanisms that tune the surface properties. O plasma etching increased the sensitivity due to increased surface oxygen content but did not affect surface roughness while the antistatic gun treatment increased surface roughness but not oxygen content. The effect of tissue fouling on CNT yarns was studied for the first time, and the relatively hydrophilic surface after O plasma etching provided better resistance to fouling than unmodified or antistatic gun treated CNTYMEs. Overall, O plasma etching and antistatic gun treatment improve the sensitivity of CNTYMEs by different mechanisms, providing the possibility to tune the CNTYME surface and enhance sensitivity.
基于碳纳米管（CNT）的微电极具有快速和选择性检测神经递质的特点。虽然已经对 CNT 微电极的不同制造策略和几何形状进行了表征，但相对较少的研究探讨了如何选择性地增强其电化学性能。在这项工作中，我们引入了两种简单、可重复、低成本且有效的 CNT 纱线微电极（CNTYME）表面修饰方法：O 等离子体蚀刻和静电枪处理。O 等离子体蚀刻是在微波等离子体系统中使用氧气气流进行的，处理的最佳时间为 1 分钟。静电枪处理通过电极表面流动离子；静电枪在 CNTYME 表面的两个触发点是优化数量。O 等离子体蚀刻后，多巴胺在 CNTYME 上的电流增加了 3 倍，静电枪处理后增加了 4 倍。当两种处理方法结合使用时，电流增加了 12 倍，表明这两种效应是由于独立的机制来调节表面特性。O 等离子体蚀刻增加了表面氧含量，从而提高了灵敏度，但不影响表面粗糙度，而静电枪处理增加了表面粗糙度，但不影响氧含量。首次研究了组织污染对 CNT 纱线的影响，O 等离子体蚀刻后的相对亲水表面比未经修饰或静电枪处理的 CNTYME 更能抵抗污染。总之，O 等离子体蚀刻和静电枪处理通过不同的机制提高了 CNTYME 的灵敏度，为调节 CNTYME 表面和提高灵敏度提供了可能性。
