title: The Role of Anion Adsorption in the Effect of Electrode Potential on Surface Plasmon Resonance Response.
abstract: Surface plasmon resonance, being widely used in bioanalytics and biotechnology, is influenced by the electrical potential of the resonant gold layer. To evaluate the mechanism of this effect, we have studied it in solutions of various inorganic electrolytes. The magnitude of the effect decreases according to the series: KBr>KCl>KF>NaClO4. The data were treated by using different models of the interface. A quantitative description was obtained for the model, which takes into account the local dielectric function of gold being affected by the free electron charge, diffuse ionic layer near the gold/water interface, and specific adsorption of halides to the gold surface with partial charge transfer. Taking into account that most biological experiments are performed in chloride-containing solutions, detailed analysis of the model at these conditions was performed. The results indicate that the chloride adsorption is the main mechanism for the influence of potential on the surface plasmon resonance. The dependencies of surface concentration and residual charge of chloride on the applied potential were determined.
authors.affiliation: Faculty of Chemistry, M.V. Lomonosov Moscow State University, 119991, Moscow, Russian Federation.
authors.forename: Veronika K
authors.identifier: http://orcid.org/0000-0001-5708-6659
authors.initials: VK
authors.lastname: Laurinavichyute
authors.affiliation: Institute of Biotechnology, Department of Nanobiotechnology, Brandenburg University of Technology Cottbus-Senftenberg, 01968, Senftenberg, Germany.
authors.forename: Shavkat
authors.identifier: http://orcid.org/0000-0002-4737-1541
authors.initials: S
authors.lastname: Nizamov
authors.affiliation: Institute of Biotechnology, Department of Nanobiotechnology, Brandenburg University of Technology Cottbus-Senftenberg, 01968, Senftenberg, Germany.
authors.forename: Vladimir M
authors.identifier: http://orcid.org/0000-0002-8427-4206
authors.initials: VM
authors.lastname: Mirsky
mesh_terms: D000327:Adsorption; D000838:Anions / Q000737:chemistry; D002712:Chlorides / Q000737:chemistry*; D004566:Electrodes; D020349:Surface Plasmon Resonance
chemical_list: D000838:Anions; D002712:Chlorides
keywords: adsorption of anions; electrochemical surface plasmon resonance; electrode effects; gold/water interface; partial charge transfer