Langguth Lutz, Femius Koenderink A
Opt Express. 2014 Jun 30;22(13):15397-409. doi: 10.1364/OE.22.015397.
Metallic nano-antennas provide strong field confinement and intensity enhancement in hotspots and thus can ultimately enhance fluorescence detection and provide ultra small detection volumes. In solution-based fluorescence measurements, the diffraction limited focus driving the nano-antenna can outshine the fluorescence originating from the hotspot and thus render the benefits of the hotspot negligible. We introduce a model to calculate the effect of a nano-antenna, or any other object creating a nontrivial intensity distribution, for fluorescence fluctuation measurements. Approximating the local field enhancement of the nano-antenna by a 3D Gaussian profile, we show which hotspot sizes and intensities are the most beneficial for an FCS measurement and compare it to realistic antenna parameters from literature.
金属纳米天线在热点区域提供了强大的场限制和强度增强，因此最终可以增强荧光检测并提供超小的检测体积。在基于溶液的荧光测量中，驱动纳米天线的衍射极限焦点可能会掩盖来自热点的荧光，从而使热点的优势变得微不足道。我们引入了一个模型来计算纳米天线或任何其他产生非平凡强度分布的物体对荧光涨落测量的影响。通过三维高斯分布来近似纳米天线的局部场增强，我们展示了哪些热点尺寸和强度对荧光相关光谱测量最为有利，并将其与文献中的实际天线参数进行了比较。
