Chen Rong-Sheng, Huang Wei-Hua, Tong Hua, Wang Zong-Li, Cheng Jie-Ke
Department of Chemistry, Wuhan University, Wuhan 430072, China.
Anal Chem. 2003 Nov 15;75(22):6341-5. doi: 10.1021/ac0340556.
Microelectrode voltammetry has been considered to be a powerful technique for single biological cell analysis and brain research. In this paper, we have developed a simple method to get highly sensitive carbon fiber nanoelectrodes (CFNE) modified by single-walled carbon nanotubes (SWNTs) on the basis of our previous work. The electrochemical behavior of SWNTs/CFNE was characterized by potassium ferricyanide, dopamine (DA), epinephrine (E), and norepinephrine (NE) using cyclic voltammetry (CV). Compared with CFNE, SWNTs/CFNE has a much larger available internal surface area per external geometric area, which is supported by SEM images. The modified electrodes show very high sensitivity and favorable electrochemical behavior toward these neurotransmitters. The peak current increases linearly with the concentration of DA, E, and NE in the range of 1.0 x 10(-)(7)-1.0 x 10(-)(4), 3.0 x 10(-)(7)-1.0 x 10(-)(4), and 5.0 x 10(-)(7)-1.0 x 10(-)(4) M, respectively. The CV detection limit (S/N = 3) of DA, E, and NE is 7.7 x 10(-)(9), 3.8 x 10(-)(8), and 4.2 x 10(-)(8) M, respectively. The modified electrode exhibited almost the same electrochemical behavior after 15 days, indicating that SWNTs/CFNE is pretty stable and has good reproducibility.
微电极伏安法被认为是用于单个生物细胞分析和脑研究的一种强大技术。在本文中，基于我们之前的工作，我们开发了一种简单的方法来制备由单壁碳纳米管（SWNTs）修饰的高灵敏度碳纤维纳米电极（CFNE）。使用循环伏安法（CV），通过铁氰化钾、多巴胺（DA）、肾上腺素（E）和去甲肾上腺素（NE）对SWNTs/CFNE的电化学行为进行了表征。与CFNE相比，SWNTs/CFNE每单位外部几何面积具有大得多的可用内表面积，扫描电子显微镜（SEM）图像证实了这一点。修饰电极对这些神经递质表现出非常高的灵敏度和良好的电化学行为。在1.0×10⁻⁷ - 1.0×10⁻⁴、3.0×10⁻⁷ - 1.0×10⁻⁴和5.0×10⁻⁷ - 1.0×10⁻⁴ M范围内，DA、E和NE的峰电流分别与浓度呈线性增加。DA、E和NE的CV检测限（S/N = 3）分别为7.7×10⁻⁹、3.8×10⁻⁸和4.2×10⁻⁸ M。修饰电极在15天后表现出几乎相同的电化学行为，表明SWNTs/CFNE相当稳定且具有良好的重现性。
