Carbon nanotube modified carbon cloth electrodes: Characterisation and application as biosensors

Abstract

Carbon nanotubes (CNTs) and nitrogen doped carbon nanotubes (CNx) modified carbon cloth (CCl) materials have been employed for the first time for the development of new electrode sensor materials, and characterised by cyclic voltammetry and electrochemical impedance spectroscopy. The voltammetric response of model electroactive species shows a close to reversible electrochemical behaviour, under diffusion control, at both functionalised CNT_CCl and CNx_CCl. Polymerisation of 3,4-ethylenedioxythiophene (EDOT) at CCl based electrodes was performed in order to decrease the material pore size and decrease sorption. The difference in charge values of PEDOT-modified CCl-based electrodes indicates that different amounts of polymer are deposited at each substrate. Glucose biosensors were constructed by immobilising glucose oxidase on top of PEDOT_CNT/CNx_CCl and the analytical properties together with operational stability were evaluated. Electrochemical impedance spectroscopy was used to evaluate interfacial and bulk properties of CNT/CNx_CCl, PEDOT_CNT/CNx_CCl and GOx_PEDOT_CNT/CNx_CCl electrodes, and differences in both capacitance and charge transfer resistance values are seen, revealing the advantages of CNT and CNx modification of CCl.