Dynamical Spectroscopy, Department of Chemistry, Technical University of Munich, 85748 Garching, Germany.
Department of Chemistry, University of Copenhagen, 2100 Copenhagen, Denmark.
Proc Natl Acad Sci U S A. 2019 Mar 5;116(10):4064-4069. doi: 10.1073/pnas.1808290116. Epub 2019 Feb 15.
Single-molecule spectroscopy (SMS) provides a detailed view of individual emitter properties and local environments without having to resort to ensemble averaging. While the last several decades have seen substantial refinement of SMS techniques, recording excitation spectra of single emitters still poses a significant challenge. Here we address this problem by demonstrating simultaneous collection of fluorescence emission and excitation spectra using a compact common-path interferometer and broadband excitation, which is implemented as an extension of a standard SMS microscope. We demonstrate the technique by simultaneously collecting room-temperature excitation and emission spectra of individual terrylene diimide molecules and donor-acceptor dyads embedded in polystyrene. We analyze the resulting spectral parameters in terms of optical lineshape theory to obtain detailed information on the interactions of the emitters with their nanoscopic environment. This analysis finally reveals that environmental fluctuations between the donor and acceptor in the dyads are not correlated.
单分子光谱学（SMS）提供了一种详细的方法来观察单个发射器的特性和局部环境，而无需依赖于集合平均。尽管在过去几十年中，SMS 技术得到了实质性的改进，但记录单个发射器的激发光谱仍然是一个重大挑战。在这里，我们通过使用紧凑型共路干涉仪和宽带激发来同时采集荧光发射和激发光谱来解决这个问题，这是对标准 SMS 显微镜的扩展。我们通过同时采集单个芘二酰亚胺分子和嵌入聚苯乙烯中的供体-受体二联体的室温激发和发射光谱来证明该技术。我们根据光学线型理论分析所得的光谱参数，以获得有关发射器与其纳米环境相互作用的详细信息。该分析最终表明，二联体中供体和受体之间的环境波动没有相关性。
