We evaluate experimentally and theoretically the role of the residual ligands and ambient environment refractive index in the optical response of a single spherical gold nanoparticle on a substrate and demonstrate the changes in the near- and far-field properties of its hybridized modes in the presence of the cetyltrimethylammonium bromide (CTAB) layer. Particularly, we show that the conventional bilayer scheme for CTAB is not relevant for colloidal nanoparticles deposited on a substrate. We show that this CTAB layer considerably changes the amplitude and localization of the confinement of the electric field, which is of prime importance in the design of plasmonic complex systems coupled to emitters. Moreover, we numerically study the influence of the CTAB layer on the modification of sensitivity of plasmonic resonances of a gold nanopshere to local refractive index changes.

中文翻译：

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CTAB表面活性剂层对单金属纳米球光学性能的影响。

我们在实验和理论上评估残余配体和周围环境折射率在基底上单个球形金纳米粒子的光学响应中的作用，并证明在存在纳米结构的情况下其杂化模式的近场和远场特性的变化。十六烷基三甲基溴化铵（CTAB）层。特别是，我们表明CTAB的常规双层方案与沉积在基材上的胶体纳米颗粒无关。我们表明，该CTAB层极大地改变了电场限制的幅度和局域性，这在耦合到发射极的等离激元复杂系统的设计中至关重要。而且，