Aligned open-ended carbon nanotube membranes for direct electrochemistry applications

A novel electrochemical electrode was prepared by transferring well-aligned, high-purity, open-end carbon nanotubes (CNTs) membrane, without any post-purification, onto the surface of glassy carbon electrodes (GCE) using Nafion as connection part. CNT membrane was made by a water-assisted selective etching chemical vapor deposition (CVD) process. The electrochemical voltammetric properties of CNT/Nafion GCE were studied by detection low level of dopamine (DA) to verify the stability and sensitivity of this electrode in a biochemical sensor application. The detection limit of DA for this electrode can reach as low as 5 × 10−8 M. By immobilization of glucose oxidase (GOD) on the above modified GCE, a GOD/CNT/Nafion GCE was obtained, and its electrochemical behavior and glucose sensor applications were investigated. The GOD/CNT/Nafion electrode can immobilize enzyme, and present two pairs of well-defined redox peaks and very good repetitiveness. The linear response range of glucose was about to be 0–0.01 mol/L and the detection limit was about 0.001 mol/L.