Controllable and Reproducible Sheath of Carbon Fibers with Single-Walled Carbon Nanotubes through Electrophoretic Deposition for In Vivo Electrochemical Measurements.
Controllable and Reproducible Sheath of Carbon Fibers with Single-Walled Carbon Nanotubes through Electrophoretic Deposition for In Vivo Electrochemical Measurements.
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DOI：
10.1021/acs.analchem.8b00303
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发表时间：
2018-03
影响因子：
7.4
通讯作者：
Tongfang Xiao;Yanan Jiang;Wenliang Ji;L. Mao
中科院分区：
文献类型：
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作者：
Tongfang Xiao;Yanan Jiang;Wenliang Ji;L. Mao
碳纳米管（CNTs）独特的电子和化学结构使其在电化学和电分析化学中得到了很好的应用；然而，将碳纳米管可重复地限制在衬底电极上，特别是微电极上的困难仍然有待解决。在这项研究中，我们开发了一种方法，用电泳沉积（EPD）将单壁碳纳米管（SWNTs）可重复地限制在碳纤维微电极（CFEs）上，用于体内测量抗坏血酸。在2.5 V下，酸处理的单壁碳纳米管均匀沉积在CFEs上。经过300°C的热处理和0.5 M H2SO4的电化学处理后，swnt包覆CFEs在-0.15 V /Ag /AgCl的电位下表现出良好的加速抗坏血酸（即抗坏血酸，在中性溶液中）的电化学氧化活性，并能在体内选择性检测抗坏血酸。EPD和预处理采用的可控程序避免了传统的手工修改方法的偏差，如滴铸和手轧，以前用于将单壁碳纳米管限制在电极表面。我们发现，在将kainic酸注入海马体诱发癫痫后的9分钟内，大鼠皮层细胞外抗坏血酸水平相对于基础水平增加了20.4±4.8% （n = 4）。本研究提供了一种可重复的方法来制备swnt包覆CFEs用于体内监测抗坏血酸，这将极大地促进未来抗坏血酸在各种生理和病理事件中的神经化学过程的研究。
The unique electronic and chemical structures of carbon nanotubes (CNTs) have well enabled their applications in electrochemistry and electroanalytical chemistry; however, the difficulty in reproducibly confining CNTs onto substrate electrodes, particularly onto microelectrodes, still remains to be addressed. In this study, we develop a method to reproducibly confine single-walled carbon nanotubes (SWNTs) onto carbon fiber microelectrodes (CFEs) with electrophoretic deposition (EPD) for in vivo measurement of ascorbate. Under 2.5 V, acid-treated SWNTs are uniformly deposited on CFEs. After thermal treatment at 300 °C followed by electrochemical treatment in 0.5 M H2SO4, the SWNT-sheathed CFEs exhibit good activity to accelerate the electrochemical oxidation of ascorbic acid (i.e., ascorbate, in a neutral solution) at an onset potential of -0.15 V vs Ag/AgCl and could in vivo selectively detect ascorbate. The controllable procedures employed for EPD and pretreatment avoid the deviation in the conventional manual modification methods such as drop casting and hand rolling previously used for confining SWNTs onto an electrode surface. With the electrodes prepared here, we find that level of extracellular ascorbate in the rat cortex increases by 20.4 ± 4.8% ( n = 4), relative to its basal level, within 9 min after infusion of kainic acid into the hippocampus to evoke epilepsy. This study offers a reproducible method to prepare SWNT-sheathed CFEs for in vivo monitoring ascorbate that would largely facilitate future studies on neurochemical processes of ascorbate in various physiological and pathological events.