Electrochemical behaviors of double-walled carbon nanotubes encapsulating ferrocene

Electrochemical properties of a novel nanohybrid material, ferrocene-filled double-walled carbon nanotubes (Fc@DWNTs), have been successfully investigated for the first time by preparing different kinds of Fc@DWNTs modified glassy carbon electrodes. One pair of surface-confined redox waves corresponding to the couple of Fc/Fc+ is obtained, indicating Fc encapsulated in DWNTs retains electrochemical activity. Significantly differing from those of ferrocene-filled single-walled carbon nanotubes (Fc@SWNTs), Fc@DWNTs shows a specific electrochemical behavior, typically exhibiting thin-layer electrochemical characteristics at low scan rates, whereas diffusion-confined characteristics at high scan rates. The results indicate that the novel nanohybrid material possessing excellent electrochemical properties may have possible applications in constructing specific chemical and biological sensors.