Individual Single-Walled Carbon Nanotubes as Nanoelectrodes for Electrochemistry

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.

Identifying and counting point defects in carbon nanotubes

“…Further lowering of V dep can result in uniform coverage of the entire SWNT (Fig. 2d), which can be useful for the templated growth of metal nanowires as previously demonstrated 22,23 . The various depositions can be done in any order and a lack of history-dependence limits the possible role the tri-potential pulse might play in producing new defects.…”

Impact of Adsorption on Scanning Electrochemical Microscopy Voltammetry and Implications for Nanogap Measurements

“…With diffusion-limited redox shuttling (diffusion coefficient, D), the steady-state mass transport coefficient, k t , becomes a function of tip-substrate separation, d (k t ~ D / d), 19 so that high mass transport rates are obtained by decreasing the UME size and tipsubstrate distances. This has fueled the trend of miniaturizing electrochemical systems, leading to the development of nanoelectrodes [20][21][22][23][24][25][26] and various nanogap systems. [27][28][29][30][31][32][33] When using nanoscale electrochemical systems for quantitative kinetic measurements, precise knowledge of electrode geometry and the physicochemical characteristics of 4 electrochemical cells is imperative.…”

Electroanalysis at discrete arrays of gold nanowire electrodes

“…[18][19][20][21]24] These desirable electrochemical properties were subsequently exploited to determine rates of electron transfer for the model redox mediators yielding, in some cases, rates two orders of magnitude higher than that previously reported. [18,20,25] Recently we reported, reported two different approaches for the fabrication of single nanowire electrodes; Nanoskiving and Ebeam lithography, respectively. These devices were successfully applied to the very sensitive detection of important biomolecules, such as hydrogen peroxide and glucose.…”