dc.contributor.author Morris, Graham P. dc.contributor.author Baker, Ruth E. dc.contributor.author Gillow, Kathryn dc.contributor.author Davis, Jason J. dc.contributor.author Gavaghan, David J. dc.contributor.author Bond, Alan M. dc.date.accessioned 2016-02-28T06:33:42Z dc.date.available 2016-02-28T06:33:42Z dc.date.issued 2015-04-24 dc.identifier.citation Morris GP, Baker RE, Gillow K, Davis JJ, Gavaghan DJ, et al. (2015) Theoretical Analysis of the Relative Significance of Thermodynamic and Kinetic Dispersion in the dc and ac Voltammetry of Surface-Confined Molecules. Langmuir 31: 4996–5004. Available: http://dx.doi.org/10.1021/la5042635. dc.identifier.issn 0743-7463 dc.identifier.issn 1520-5827 dc.identifier.pmid 25853230 dc.identifier.doi 10.1021/la5042635 dc.identifier.uri http://hdl.handle.net/10754/599979 dc.description.abstract © 2015 American Chemical Society. Commonly, significant discrepancies are reported in theoretical and experimental comparisons of dc voltammograms derived from a monolayer or close to monolayer coverage of redox-active surface-confined molecules. For example, broader-than-predicted voltammetric wave shapes are attributed to the thermodynamic or kinetic dispersion derived from distributions in reversible potentials (E$^{0}$) and electrode kinetics (k$^{0}$), respectively. The recent availability of experimentally estimated distributions of E$^{0}$ and k$^{0}$ values derived from the analysis of data for small numbers of surface-confined modified azurin metalloprotein molecules now allows more realistic modeling to be undertaken, assuming the same distributions apply under conditions of high surface coverage relevant to voltammetric experiments. In this work, modeling based on conventional and stochastic kinetic theory is considered, and the computationally far more efficient conventional model is shown to be equivalent to the stochastic one when large numbers of molecules are present. Perhaps unexpectedly, when experimentally determined distributions of E$^{0}$ and k$^{0}$ are input into the model, thermodynamic dispersion is found to be unimportant and only kinetic dispersion contributes significantly to the broadening of dc voltammograms. Simulations of ac voltammetric experiments lead to the conclusion that the ac method, particularly when the analysis of kinetically very sensitive higher-order harmonics is undertaken, are far more sensitive to kinetic dispersion than the dc method. ac methods are therefore concluded to provide a potentially superior strategy for addressing the inverse problem of determining the k$^{0}$ distribution that could give rise to the apparent anomalies in surface-confined voltammetry. dc.description.sponsorship This publication is based on work supported by award no. KUK-C1-013-04, made by King Abdullah University of Science and Technology (KAUST). Financial support from the Australian Research Council is also gratefully acknowledged. dc.publisher American Chemical Society (ACS) dc.title Theoretical Analysis of the Relative Significance of Thermodynamic and Kinetic Dispersion in the dc and ac Voltammetry of Surface-Confined Molecules dc.type Article dc.identifier.journal Langmuir dc.contributor.institution University of Oxford, Oxford, United Kingdom dc.contributor.institution Monash University, Melbourne, Australia kaust.grant.number KUK-C1-013-04 dc.date.published-online 2015-04-24 dc.date.published-print 2015-05-05
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