单壁碳纳米管修饰的高灵敏纳米碳纤维电极

High Sensitive Carbon Fiber Nanoelectrodes Modified by Single-walled Carbon Nanotubes

碳纳米管已被应用于电极材料, 但未得到良好的电化学伏安行为[1]; 且由于碳纳米管的直径很小（几到数十纳米）, 制作单根的碳纳米管电极非常困难, 难以实际应用.碳纳米管用于修饰电极已得到更多重视[2~4], 但都在常规尺寸（毫米级）的电极上进行, 这样的电极不适于在生物微环境和毛细管电泳电化学检测中应用.

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 a high sensitive carbon fiber nanoelectrode(CFNE) modified by single-walled carbon nanotubes(SWNTs) on the basis of our previous work. The electrochemical behavior of SWNTs modified CFNE was characterized by dopamine(DA) by using cyclic voltammetry(CV). Compared with CFNE, SWNTsmodified CFNE has almost the same geometric area but greater available internal surface area per external geometric area, which was supported by SEM images. The modified electrode shows a very high sensitivity and favorable electro-catalytic behavior toward dopamine. The peak current increases linearly with the concentration of DA in the range of 1.0×10-7-1. 0X 10-4 mol/L. The CV detection limit(S/N= 3) of DA is 7. 7× 10-9 mol/ L. The modified electrode exhibited almost the same electrochemical behavior after 15 d. It indicates that SWNTs modified CFNE is pretty stable and has a good reproducibility.