Superresolved nanoscopy using Brownian motion of fluorescently labeled gold nanoparticles

The fundamental limit set by the wavelength of light can be overcome using methods of superresolution localization microscopy. These methods require labeling of the sample with fluorescent molecules and are time consuming as repeated cycles of activation and photobleaching of the sample are required. Alternatively, we propose a simplified approach that is free from direct labeling with fluorescence molecules and does not require the repeated cycles of activation and photobleaching. The method uses fluorescently labeled gold nanoparticles in an aqueous solution that are distributed on top of the sample. The nanoparticles move in random Brownian motion and obscure different areas of the sample, while the scene is being imaged sequentially. By conducting the proper postprocessing, a superresolution image can be generated. The method is validated both by numerical simulations as well as by experimental data.