title: Simulation-Based Approach to Determining Electron Transfer Rates Using Square-Wave Voltammetry.
abstract: The efficiency with which square-wave voltammetry differentiates faradic and charging currents makes it a particularly sensitive electroanalytical approach, as evidenced by its ability to measure nanomolar or even picomolar concentrations of electroactive analytes. Because of the relative complexity of the potential sweep it uses, however, the extraction of detailed kinetic and mechanistic information from square-wave data remains challenging. In response, we demonstrate here a numerical approach by which square-wave data can be used to determine electron transfer rates. Specifically, we have developed a numerical approach in which we model the height and the shape of voltammograms collected over a range of square-wave frequencies and amplitudes to simulated voltammograms as functions of the heterogeneous rate constant and the electron transfer coefficient. As validation of the approach, we have used it to determine electron transfer kinetics in both freely diffusing and diffusionless surface-tethered species, obtaining electron transfer kinetics in all cases in good agreement with values derived using non-square-wave methods.
authors.forename: Philippe
authors.identifier: 0000-0002-0490-7115
authors.initials: P
authors.lastname: Dauphin-Ducharme
authors.forename: Netzahualcóyotl
authors.identifier: 0000-0002-2740-6276
authors.initials: N
authors.lastname: Arroyo-Currás
authors.forename: Martin
authors.initials: M
authors.lastname: Kurnik
authors.affiliation: CIC bioGUNE , Bizkaia Technology Park, Building 801 A, 48170 Derio, Spain.
authors.forename: Gabriel
authors.initials: G
authors.lastname: Ortega
authors.forename: Hui
authors.initials: H
authors.lastname: Li
authors.forename: Kevin W
authors.identifier: 0000-0003-4772-8771
authors.initials: KW
authors.lastname: Plaxco
mesh_terms: D004579:Electron Transport; D004583:Electrons; D007700:Kinetics