Defect Sites Modulate Fouling Resistance on Carbon-Nanotube Fiber Electrodes
Defect Sites Modulate Fouling Resistance on Carbon-Nanotube Fiber Electrodes
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DOI：
10.1021/acssensors.9b00161
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发表时间：
2019-04-01
期刊：
影响因子：
8.9
通讯作者：
Ross, Ashley E.
中科院分区：
文献类型：
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作者：
Weese, Moriah E.;Krevh, Rachel A.;Ross, Ashley E.
碳纳米管(CNT)纤维电极已成为快速扫描循环伏安法(FSCV)检测神经递质的电极材料。碳纳米管纤维电极的独特性能，如增加电子传递、灵敏度、波形应用频率无关性和抗污垢，使其成为FSCV理想的生物传感器。特别是，它们对污垢的抵抗力已经被观察到好几年了，但有助于污垢抵抗力的具体物理性质一直存在争议。在这里，我们调查了表面缺陷位置的存在在多大程度上减弱了FSCV对化学和生物的污染。我们将传统的碳纤维微电极(CFME)与原始的碳纳米管和功能化的碳纳米管进行了比较。CFME和功能化的碳纳米管高度无序，表面有大量的缺陷位。与有目的地功能化的碳纳米管和CFME相比，原始的碳纳米管具有更少的缺陷。用扫描电子显微镜(SEM)、拉曼光谱和能量色散光谱(EDS)对电极表面进行了表征。使用5-羟色胺来研究化学污染，5-羟色胺是一种广为人知的神经递质，因电极污染而臭名昭著。为了评估生物污垢，将电极植入脑组织2小时。与原始的碳纳米管相比，碳表面的缺陷位置可以抵抗生物污垢，但对5-羟色胺的检测是不利的。总体而言，我们深入了解了电极表面决定FSCV污垢阻力的程度。这项工作证明，在设计污垢电阻传感器时，需要仔细考虑碳纳米管材料的表面。
Carbon nanotube (CNT) fiber electrodes have become increasingly popular electrode materials for neurotransmitter detection with fast-scan cyclic voltammetry (FSCV). The unique properties of CNT fiber electrodes like increased electron transfer, sensitivity, waveform application frequency independence, and resistance to fouling make them ideal biological sensors for FSCV. In particular, their resistance to fouling has been observed for several years, but the specific physical properties which aid in fouling resistance have been debated. Here, we investigate the extent to which the presence of defect sites on the surface attenuate both chemical and biological fouling with FSCV. We compared traditional carbon-fiber microelectrodes (CFMEs) to pristine CNTs and functionalized CNTs. CFMEs and functionalized CNTs are highly disordered with a great deal of defect sites on the surface. The pristine CNTs have fewer defects compared to the purposefully functionalized CNTs and CFMEs. All electrode surfaces were characterized by a combination of scanning electron microscopy (SEM), Raman spectroscopy, and energy dispersive spectroscopy (EDS). Chemical fouling was studied using serotonin, a popular neurotransmitter notoriously known for electrode fouling. To assess biological fouling, electrodes were implanted in brain tissue for 2 h. Defect sites on the carbon were shown to resist biofouling compared to pristine CNTs but were detrimental for serotonin detection. Overall, we provide insight into the extent to which the electrode surface dictates fouling resistance with FSCV. This work provides evidence that careful considerations of the surface of the CNT material are needed when designing sensors for fouling resistance.