In this contribution, we quantify the fine-tuning of surface plasmon resonance via nanoparticle coating of gold SPR chips. We target preparation of atomically flat surface with defined charge, needed for scanning probe characterization of biomolecules, with simultaneous optimization of in situ SPR sensitivity during immobilization of these molecules. Using total internal reflection ellipsometry, we show that the goal can be achieved by combination of charge-stabilized silver nanoparticles over underlying gold chip of reduced thickness. The provided formulas for optimal silver to gold thickness relation are valid for arbitrary analyte and the method was experimentally verified on binding of Rtt103 protein.

在此贡献中，我们通过金SPR芯片的纳米颗粒涂层量化了表面等离子体激元共振的微调。我们的目标是制备具有定义电荷的原子平面，这对于扫描生物分子的探针表征是必需的，同时在固定这些分子的过程中同时优化原位SPR敏感性。使用全内反射椭圆光度法，我们表明可以通过将电荷稳定的银纳米颗粒结合在厚度减小的底层金芯片上来实现该目标。所提供的最佳银与金厚度关系的公式对任意分析物均有效，并且该方法已通过Rtt103蛋白的结合实验进行了验证。