Single-Fluorophore Diffusion in a Lipid Membrane over a Subwavelength Aperture
Jérôme Wenger, Hervé Rigneault, José Dintinger, Didier Marguet and Pierre-François Lenne
We use submicrometer apertures milled in an aluminium film to study the diffusion dynamics of β-Bodipy-FL-C5-HPC (Bodipy-PC) fluorophores in a lipid dioleoylphosphatidylcholine (DOPC) multilayer. The observation volume is limited by the aperture diameter, well below the optical wavelength. This spatial resolution improvement comes together with an enhancement of the detected fluorescence per molecule as compared to an open sample, with a significant increase up to 3.5 times.