Mislocalization in Plasmon-Enhanced Single-Molecule Fluorescence Microscopy as a Dynamical Young's Interferometer
Mislocalization in Plasmon-Enhanced Single-Molecule Fluorescence Microscopy as a Dynamical Young's Interferometer
复制标题
DOI：
10.1021/acsphotonics.8b00372
复制
发表时间：
2018-08-01
期刊：
影响因子：
7
通讯作者：
Masiello, David J.
中科院分区：
文献类型：
--
作者：
Goldwyn, Harrison J.;Smith, Kevin C.;Masiello, David J.
错误定位是在等离子体增强超分辨荧光显微镜中无法定位单个分子发射体位置的定量测量。这是由于一种不幸的副作用，当引入等离子体纳米天线来增强分子的荧光信号时，这种副作用扰乱了分子荧光信号的空间轮廓。在这篇文章中，我们提出了一个简单直观的理论模型来理解等离子体增强超分辨荧光显微镜中的错位问题。特别地，我们推导了失域化的解析表达式，并明确地证明了它如何依赖于来自分子和等离子体发射体的相干发射的宏观干涉和耦合系统的微观动力学。为了推导出这个表达式，我们利用了对Fano干涉问题的类比，并证明了强度分布中的空间不对称性可以被封装为严格依赖于基本系统性质的单个有效参数。我们进一步在分子和等离子体发射体杂交的背景下阐明了错误定位的原因，并解析地展示了定位误差如何依赖于发射体的相对分离、取向、失谐和极化率。最后，我们推导了一种基于模型的特定分子偶极取向的等离子体增强单分子荧光图像的形式，并证明了它在定位分子位置方面明显优于标准的高斯拟合法。
Mislocalization is a quantitative measure of the inability to locate the positions of individual molecular emitters in plasmon-enhanced super-resolution fluorescence microscopy. It is due to an unfortunate side-effect that scrambles the spatial profile of a molecule's fluorescence signal when plasmonic nanoantennas are introduced to boost that signal. In this article, we present an understanding of the mislocalization problem in plasmon-enhanced super-resolution fluorescence microscopy based upon a simple and intuitive theoretical model. In particular, we derive an analytic expression for mislocalization and demonstrate explicitly how it depends upon both the macroscopic interference of the coherent emission from molecular and plasmonic emitters and the microscopic dynamics of the coupled system. To derive this expression, we draw upon an analogy to the Fano interference problem and show that the spatial asymmetry in the intensity profile can be encapsulated into a single effective parameter that depends rigorously upon basic system properties. We further elucidate the causes of mislocalization within the context of hybridization between molecular and plasmonic emitters and show analytically how the localization error depends upon the relative separation, orientation, detuning, and polarizability of the emitters. Lastly, we derive a new model-based form of the plasmon-enhanced single-molecule fluorescence image for specified molecular dipole orientations and demonstrate that it significantly outperforms standard Gaussian fitting in locating the position of the molecule.