Open Access Nano Express

Single-step electrochemical functionalization of double-walled carbon nanotube (DWCNT) membranes and the demonstration of ionic rectification

Xin Zhan1, Ji Wu23, Zhiqiang Chen2 and Bruce J Hinds12*

Author affiliations

1 Department of Chemistry, University of Kentucky, Lexington, KY 40506, USA

2 Department of Chemical and Materials Engineering, University of Kentucky, Lexington, KY 40506, USA

3 Current address: Department of Chemistry, Georgia Southern University, Statesboro, GA 30460, USA

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Citation and License

Nanoscale Research Letters 2013, 8:279  doi:10.1186/1556-276X-8-279

Published: 10 June 2013

Abstract

Carbon nanotube (CNT) membranes allow the mimicking of natural ion channels for applications in drug delivery and chemical separation. Double-walled carbon nanotube membranes were simply functionalized with dye in a single step instead of the previous two-step functionalization. Non-faradic electrochemical impedance spectra indicated that the functionalized gatekeeper by single-step modification can be actuated to mimic the protein channel under bias. This functional chemistry was proven by a highly efficient ion rectification, wherein the highest experimental rectification factor of ferricyanide was up to 14.4. One-step functionalization by electrooxidation of amine provides a simple and promising functionalization chemistry for the application of CNT membranes.

Keywords:
Carbon nanotube membranes; Rectification; Voltage gatekeeper; Amine electrooxidation