Laurinavichyute Veronika K, Nizamov Shavkat, Mirsky Vladimir M
Faculty of Chemistry, M.V. Lomonosov Moscow State University, 119991, Moscow, Russian Federation.
Institute of Biotechnology, Department of Nanobiotechnology, Brandenburg University of Technology Cottbus-Senftenberg, 01968, Senftenberg, Germany.
Chemphyschem. 2017 Jun 20;18(12):1552-1560. doi: 10.1002/cphc.201601288. Epub 2017 May 3.
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>NaClO . 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.
表面等离子体共振在生物分析和生物技术中被广泛应用，它会受到共振金层电势的影响。为了评估这种效应的机制，我们在各种无机电解质溶液中对其进行了研究。效应的大小按照以下顺序递减：KBr>KCl>KF>NaClO。通过使用不同的界面模型对数据进行了处理。对于考虑了受自由电子电荷影响的金的局部介电函数、金/水界面附近的扩散离子层以及卤化物通过部分电荷转移对金表面的特异性吸附的模型，获得了定量描述。考虑到大多数生物学实验是在含氯溶液中进行的，因此在这些条件下对该模型进行了详细分析。结果表明，氯的吸附是电势影响表面等离子体共振的主要机制。确定了氯的表面浓度和剩余电荷与所施加电势的依赖关系。
