Three-dimensional tracking of fluorescent nanoparticles with subnanometer precision by use of off-focus imaging

Author :Michael Speidel, Alexandr JonĂ¡?s, and Ernst-Ludwig Florin
Publication :Optics Letters
Publisher :Optical Society of America
Volume :28
Number :2
Pages :69-71
Year :2003

We show that the position of a f luorescent nanoparticle can be measured in three dimensions with subnanometer
precision and 100-ms temporal resolution by use of standard epif luorescence video imaging in off-focus
mode. The particle can be tracked without feedback in a volume of at least 40 mm 3 60 mm 3 3 mm. With
the technique presented, the structure’mobility relationship of 216-nm latex particle in a porous polymer
network was studied in three dimensions.