We demonstrate the all-optical reconstruction of gold nanoparticle geometry using super-resolution microscopy. We employ DNA-PAINT to get exquisite control over the (un)binding kinetics by the number of complementary bases and salt concentration, leading to localization accuracies of ∼5 nm. We employ a dye with an emission spectrum strongly blue-shifted from the plasmon resonance to minimize mislocalization due to plasmon-fluorophore coupling. We correlate the all-optical reconstructions with atomic force microscopy images and find that reconstructed dimensions deviate by no more than ∼10%. Numerical modeling shows that this deviation is determined by the number of events per particle, and the signal-to-background ratio in our measurement. We further find good agreement between the reconstructed orientation and aspect ratio of the particles and single-particle scattering spectroscopy. This method may provide an approach to all-optically image the geometry of single particles in confined spaces such as microfluidic circuits and biological cells, where access with electron beams or tip-based probes is prohibited.

中文翻译：

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使用超高分辨率显微镜对金纳米颗粒几何形状进行全光学成像

我们展示了使用超分辨率显微镜对金纳米粒子几何形状的全光学重建。我们使用DNA-PAINT通过互​​补碱基的数量和盐浓度来精确控制（非）结合动力学，从而导致〜5 nm的定位精度。我们使用的染料具有从等离振子共振强烈蓝移的发射光谱，以最大程度地减少由于等离激元-荧光团偶联而引起的定位错误。我们将全光学重建与原子力显微镜图像相关联，发现重建后的尺寸偏差不超过10％。数值模型表明，这种偏差取决于每个粒子的事件数量以及我们的测量中的信噪比。我们进一步发现粒子的重构方向和长宽比与单粒子散射光谱法之间具有良好的一致性。该方法可以提供一种方法，对狭窄空间（如微流回路和生物细胞）中的单个粒子的几何结构进行全光学成像，在这些空间中，禁止使用电子束或基于尖端的探针进行访问。