《Individual single-walled carbon nanotubes as nanoelectrodes for electrochemistry》.pdf

NANO LETTERS Individual Single-Walled Carbon 2005 Vol. 5, No. 1 Nanotubes as Nanoelectrodes for 137142 Electrochemistry Iddo Heller, Jing Kong,† Hendrik A. Heering, Keith A. Williams,‡ Serge G. Lemay, and Cees Dekker* Ka li Institute of Nanoscience, Delft Uniersity of Technology, Lorentzweg 1, 2628 CJ Delft, The Netherlands Received October 31, 2004; Revised Manuscript Received November 26, 2004 ABSTRACT We demonstrate the use of individual single-walled carbon nanotubes (SWNTs) as nanoelectrodes for electrochemistry. SWNTs were contacted by nanolithography, and cyclic voltammetry was performed in aqueous solutions. Interestingly, metallic and semiconducting SWNTs yielded similar steady-state voltammetric curves. We clarify this behavior through a model that considers the electronic structure of the SWNTs. Interfacial electron transfer to the SWNTs is observed to be very fast but can nonetheless be resolved due to the nanometer critical dimension of SWNTs. These studies demonstrate the potential of using a SWNT as a model carbon nanoelectrode for electrochemistry. Electrodes with nanometer dimensions provide exciting new Large ensembles of carbon nanotubes have been used as tools for electrochemical studies. The small dimensions lead electrode material for electrochemical experiments, which t