Micromirror total internal reflection microscopy for high-performance single particle tracking at interfaces

• Published in: arXiv.org
• Main Authors: Meng, Xuanhui, Sonn-Segev, Adar, Schumacher, Anne, Cole, Daniel, Young, Gavin, Thorpe, Stephen, Style, Robert W, Dufresne, Eric R, Kukura, Philipp
• Format: Paper
• Language: English
• Published: Ithaca Cornell University Library, arXiv.org 17.03.2021
• Subjects: Field of view; Fluorescence; Gold; Lipids; Liquid-liquid interfaces; Localization; Microscopy; Nanoparticles; Particle tracking; Physical sciences; Scattering; Temporal resolution
• ISSN: 2331-8422

Single particle tracking has found broad applications in the life and physical sciences, enabling the observation and characterisation of nano- and microscopic motion. Fluorescence-based approaches are ideally suited for high-background environments, such as tracking lipids or proteins in or on cells, due to superior background rejection. Scattering-based detection is preferable when localisation precision and imaging speed are paramount due to the in principle infinite photon budget. Here, we show that micromirror-based total internal reflection dark field microscopy enables background suppression previously only reported for interferometric scattering microscopy, resulting in nm localisation precision at 6 \(\mu\)s exposure time for 20 nm gold nanoparticles with a 25 x 25 \(\mu\)m\(^{2}\) field of view. We demonstrate the capabilities of our implementation by characterizing sub-nm deterministic flows of 20 nm gold nanoparticles at liquid-liquid interfaces. Our results approach the optimal combination of background suppression, localisation precision and temporal resolution achievable with pure scattering-based imaging and tracking of nanoparticles at regular interfaces.