Taylor Adam, Verhoef René, Beuwer Michael, Wang Yuyang, Zijlstra Peter
Molecular Biosensing for Medical Diagnostics, Faculty of Applied Physics, and Institute of Complex Molecular Systems, Eindhoven University of Technology, PO Box 513, 5600 MB Eindhoven, The Netherlands.
J Phys Chem C Nanomater Interfaces. 2018 Feb 1;122(4):2336-2342. doi: 10.1021/acs.jpcc.7b12473. Epub 2018 Jan 3.
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.
我们展示了使用超分辨率显微镜对金纳米颗粒几何形状进行全光学重建。我们采用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，从而实现约5纳米的定位精度。我们使用一种发射光谱与等离子体共振强烈蓝移的染料，以尽量减少由于等离子体-荧光团耦合导致的定位错误。我们将全光学重建与原子力显微镜图像相关联，发现重建尺寸的偏差不超过约10%。数值模拟表明，这种偏差由每个颗粒的事件数量以及我们测量中的信噪比决定。我们还发现颗粒的重建取向和纵横比与单颗粒散射光谱之间具有良好的一致性。这种方法可能提供一种全光学成像方法，用于对诸如微流控电路和生物细胞等受限空间中的单颗粒几何形状进行成像，在这些空间中电子束或基于探针的访问是被禁止的。
