On the steady-state assumption and its application to the rotating disk voltammetry of adsorbed enzymes
Data(s) |
01/01/2005
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Resumo |
Rotating disk voltammetry is routinely used to study electrochemically driven enzyme catalysis because of the assumption that the method produces a steady-state system. This assumption is based on the sigmoidal shape of the voltammograms. We have introduced an electrochemical adaptation of the King-Altman method to simulate voltammograms in which the enzyme catalysis, within an immobilized enzyme layer, is steadystate. This method is readily adaptable to any mechanism and provides a readily programmable means of obtaining closed form analytical equations for a steady-state system. The steady-state simulations are compared to fully implicit finite difference (FIFD) simulations carried out without any steady-state assumptions. On the basis of our simulations, we conclude that, under typical experimental conditions, steady-state enzyme catalysis is unlikely to occur within electrode-immobilized enzyme layers and that typically sigmoidal rotating disk voltammograms merely reflect a mass transfer steady state as opposed to a true steady state of enzyme intermediates at each potential. |
Identificador | |
Idioma(s) |
eng |
Publicador |
Amer Chemical Soc |
Palavras-Chave | #Chemistry, Physical #Catalytic Voltammetry #Electrode #Transport #C1 #250107 Electrochemistry #780103 Chemical sciences |
Tipo |
Journal Article |