High sensitive carbon fiber nanoelectrodes modified by single-walled carbon nanotubes

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 electrocatalytic behavior toward dopamine. The peak current increases linearly with the concentration of DA in the range of 1.0 X 10(-7)-1.0 X 10(-4) mol/L. The CV detection limit(S/N = 3) of DA Is 7.7 X 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.