Protein-film voltammetry: A theoretical study of the temperature effect using square-wave voltammetry

Abstract

Square-wave voltammetry of surface redox reactions is considered as an adequate model for a protein-film voltammetric setup. Here we develop a theoretical approach to analyze the effects of temperature on squarewave voltammograms. The performed simulations address the surface redox reactions featuring slow, modest and fast electron transfer. The theoretical calculations show that the temperature affects the squarewave voltammetric responses in a complex way resulting in a variety of peak shapes. Temperature effects on the phenomena known as "quasireversible maximum" and "split SW peaks" are also analyzed. The simulated results can be used to analyze the redox mechanisms and kinetic parameters of electron transfer reactions in protein-film criovoltammetry and other surface-confined redox systems. Our analysis also shows how "abnormal" features present in some square-wave voltammetric studies can easily be misinterpreted by postulating "multiple species", "stable radicals", or additional processes. Finally we provide a simple algorithm to use the "quasireversible maximum" to determine the activation energy of electron transfer reactions by surface redox systems.

Catalytic mechanism in successive two-step protein-film voltammetry—Theoretical study in square-wave voltammetry

“…Alternatively, the electron transfer kinetic parameters can be estimated from the frequency dependence analysis of the half-peak widths of square-wave voltammograms, by using the analytical equations provided in our recent theoretical work [29]. For the determination of the electron transfer coefficients α, one can also use the methodology elaborated in our recent work [28]. In order to calculate the Michaelis-Menten rate constant of catalytic reaction, one can take advantage of the methodology and analytical equations explained in our initial work concerning the surface EC′ mechanism [17,25].…”

“…The redox transformations of the aforementioned proteins can only be described by theoretical models considering successive two-step electron transfer. In the last few years, we started theoretical considerations of various redox mechanisms relevant to protein-film voltammetry, and we published scores of theoretical and experimental works in the past decade [17,21,22,25,[27][28][29][30][31][32][33][34]. In this paper we consider the surface catalytic mechanism that follows the two-step surface EE (electron-electron) redox reaction, which can be described by the following reaction scheme: The common designation of this complex protein-film redox mechanism in the electrochemical terminology is a surface EEC′, or surface EECat [13,14].…”

Surface ECE mechanism in protein film voltammetry—a theoretical study under conditions of square-wave voltammetry

“…1 the value of the electron transfer coefficient of the second step α 2 is already known. For the determination of α 2 , one is recommended to use the procedure developed in our most recent article [25].…”

Square‐Wave Voltammetry: A Review on the Recent Progress

“…In the reviewed period significant contributions in the theory of SWV have been done by the research groups of Lovric [18][19][20][22][23][24][25][26][27][28][29], Molina [17,[30][31][32][33][34][35], Compton [36][37][38][39], Mirceski [40][41][42][43], Gulaboski [44][45][46][47], and others [48][49][50]. The theory refers to a variety of electrode mechanisms including dissolved or immobilized redox couples at macroscopic planar or microelectrodes, as well as processes undergoing in a restricted diffusion space.…”