Abstract
We introduce a method for detecting and tracking small particles in a solution near a surface. The method is based on blocking the backreflected illumination beam in an objective-type total internal reflection microscope, leaving unhindered the light scattered by the particles and resulting in dark-field illumination. Using this method, we tracked the motion of 60-nm polystyrene beads with a signal-to-noise ratio of 6 and detected 20-nm gold particles with a signal-to-noise ratio of 5. We illustrate the method’s use by following the Brownian motion of small beads attached by short DNA tethers to a substrate.
© 2001 Optical Society of America
Full Article | PDF ArticleMore Like This
F. Verpillat, F. Joud, P. Desbiolles, and M. Gross
Opt. Express 19(27) 26044-26055 (2011)
Adam Wax, Changhuei Yang, Ramachandra R. Dasari, and Michael S. Feld
Appl. Opt. 40(24) 4222-4227 (2001)
Michael A. Taylor and Warwick P. Bowen
Appl. Opt. 52(23) 5718-5723 (2013)