Carbon nanotubes on low resistance monolayer-modified glassy carbon electrode as chemo/biosensor

A novel carbon nanotubes (CNTs) film-modified electrode was developed by controllable adsorption of the CNTs onto the monolayer of dodecylamine chemically modified glassy carbon electrode (GCE). The electrochemical characteristics of the dodecylamine monolayer-modified GCE were examined by electrochemical impedance spectroscopy and cyclic voltammetry. Compared with the self-assembled monolayer (SAM) of dodecanethiol-modified gold electrode, the prepared dodecylamine monolayer-modified GCE presented a smaller resistance and a higher capacitance. In addition, after single wall carbon nanotubes (SWCNTs) were controllably adsorbed onto the both modified electrodes by hydrophobic interaction, the dodecylamine monolayer-modified GCE showed a larger capacitance than that of bare GCE for its small resistance and good conductivity of CNTs, but the SAM of dodecanethiol-modified gold electrode was failed to achieve the same result. Furthermore, the proposed SWCNTs dodecylamine monolayer-modified GCE was successfully used to determine dopamine in the presence of ascorbic acid after it adsorbed the ssDNA.