Resolving Sub-Diffraction Limit Encounters in Nanoparticle Tracking Using Live Cell Plasmon Coupling Microscopy

摘要

We use plasmon coupling between individual gold nanoparticle labels to monitor sub-diffraction limit distances in live cell nanoparticle tracking experiments. While the resolving power of our optical microscope is limited to ~500 nm, we improve this by more than an order of magnitude by detecting plasmon coupling between individual gold nanoparticle labels using a ratiometric detection scheme. We apply this plasmon coupling microscopy to resolve the interparticle separations during individual encounters of gold nanoparticle labeled fibronectin-integrin complexes in living HeLa cells.