Department of Chemistry and Center for Behavioral Neuroscience, American University, Washington, DC 20016, USA.
Sensors (Basel). 2020 Feb 20;20(4):1173. doi: 10.3390/s20041173.
Carbon fiber-microelectrodes (CFMEs) have been the standard for neurotransmitter detection for over forty years. However, in recent years, there have been many advances of utilizing alternative nanomaterials for neurotransmitter detection with fast scan cyclic voltammetry (FSCV). Recently, carbon nanotube (CNT) yarns have been developed as the working electrode materials for neurotransmitter sensing capabilities with fast scan cyclic voltammetry. Carbon nanotubes are ideal for neurotransmitter detection because they have higher aspect ratios enabling monoamine adsorption and lower limits of detection, faster electron transfer kinetics, and a resistance to surface fouling. Several methods to modify CFMEs with CNTs have resulted in increases in sensitivity, but have also increased noise and led to irreproducible results. In this study, we utilize commercially available CNT-yarns to make microelectrodes as enhanced neurotransmitter sensors for neurotransmitters such as serotonin. CNT-yarn microelectrodes have significantly higher sensitivities (peak oxidative currents of the cyclic voltammograms) than CFMEs and faster electron transfer kinetics as measured by peak separation (Δ) values. Moreover, both serotonin and dopamine are adsorption controlled to the surface of the electrode as measured by scan rate and concentration experiments. CNT yarn microelectrodes also resisted surface fouling of serotonin onto the surface of the electrode over thirty minutes and had a wave application frequency independent response to sensitivity at the surface of the electrode.
碳纤维微电极（CFMEs）已经作为神经递质检测的标准超过四十年了。然而，近年来，利用替代纳米材料进行神经递质检测的研究取得了许多进展，其中包括快速扫描循环伏安法（FSCV）。最近，碳纳米管（CNT）纱线已经被开发出来作为工作电极材料，用于具有快速扫描循环伏安法的神经递质传感能力。碳纳米管非常适合用于神经递质检测，因为它们具有更高的纵横比，能够实现单胺吸附，并且具有更低的检测限、更快的电子转移动力学以及对表面污染的抗性。几种将 CNT 与 CFME 进行修饰的方法已经提高了灵敏度，但也增加了噪声并导致结果不可重现。在本研究中，我们利用市售的 CNT 纱线来制作微电极，作为增强型神经递质传感器，用于检测神经递质，如血清素。与 CFME 相比，CNT 纱线微电极具有更高的灵敏度（循环伏安图的峰值氧化电流），并且通过峰分离（Δ）值测量，具有更快的电子转移动力学。此外，通过扫描速率和浓度实验测量，血清素和多巴胺都被吸附到电极表面，受到控制。CNT 纱线微电极还能够抵抗三十分钟内血清素在电极表面的污染，并且在电极表面具有与应用频率无关的响应灵敏度。
