We demonstrate high-resolution, high-speed 3D nanoparticle tracking using angled micromirrors. When angled micromirrors are introduced into the field of view of an optical microscope, reflected side-on views of a diffusing nanoparticle are projected alongside the usual direct image. The experimental design allows us to find the 3D particle trajectory using fast, centroid-based image processing, with no nonlinear computing operations. We have tracked polystyrene particles of 190 nm diameter with position measurement precision <20 nm in 3D with 3 ms frame duration (i.e., at an imaging rate >330 frames per second). Because the image processing requires only ≈1 ms per frame, this technique could enable real-time feedback-controlled nanoparticle assembly applications with nanometer precision.
Citation: ACS Nano
Pub Type: Journals
orthogonal tracking microscopy, particle tracking, three-dimensional microscopy, optical microscopy, digital video microscopy, multiple vantage point microscopy