Electrochemical Correlation Spectroscopy in Nanofluidic Cavities

We introduce both theoretically and experimentally a new electrochemical technique based on measuring the fluctuations of the faradaic current during redox cycling. By analogy with fluorescence correlation spectroscopy (FCS), we refer to this technique as electrochemical correlation spectroscopy (EC...

Full description

Saved in:
Bibliographic Details
Published in:Analytical chemistry (Washington) 2009-10, Vol.81 (19), p.8203-8212
Main Authors: Zevenbergen, Marcel A. G., Singh, Pradyumna S., Goluch, Edgar D., Wolfrum, Bernhard L., Lemay, Serge G.
Format: Article
Language:English
Subjects:
Analytical chemistry
Chemistry
Electric currents
Electrochemical methods
Electrodes
Exact sciences and technology
Spectrometric and optical methods
Spectrum analysis
Citations: Items that this one cites
Items that cite this one
Online Access:Get full text
Tags: Add Tag
No Tags, Be the first to tag this record!
Description
Summary:We introduce both theoretically and experimentally a new electrochemical technique based on measuring the fluctuations of the faradaic current during redox cycling. By analogy with fluorescence correlation spectroscopy (FCS), we refer to this technique as electrochemical correlation spectroscopy (ECS). We first derive an analytical expression of the power spectral density for the fluctuations in a thin-layer-cell geometry. We then show agreement with measurements using ferrocenedimethanol, Fc(MeOH)2, in water and in acetonitrile in microfabricated thin-layer cells with a ∼70 nm electrode spacing. The fluctuation spectra provide detailed information about the adsorption dynamics of Fc(MeOH)2, which cause an apparent slowing of Brownian motion. We furthermore observe high-frequency fluctuations from which we estimate the rates of adsorption and desorption.
ISSN:0003-2700
1520-6882
DOI:10.1021/ac9014885