Plasmonic magnifiers of single molecule dynamics

Ziel

This project will develop a new method for spatial manipulation of light by designing and validating assemblies of plasmonic nanostructures and fluorophores to advance visualization of densely packed biological structures and their dynamics. The visualization of densely packed biological structures is extremely challenging, yet crucial for understanding dynamic biological processes in virtually any context; light manipulation at the nanoscale using plasmonic nanoparticles has the potential to magnify nanoscopic sample structure while simultaneously enhancing the optical response beyond the capabilities of current super-resolution microscopy techniques. While the ability of metal nanostructures to enhance the response of fluorophores has been utilized for decades, we are still far from understanding the underlying mechanisms of plasmonic enhancement. To fully exploit the potential of this approach, we need to know how spectral overlap between the plasmonic nanoparticle and the absorption and emission channels of the fluorophore affects the coupling efficiency and spatial projection. To translate these effect into applications, we have to understand how the fluorophore-particle distance affects the far-field projection of the fluorophore. We will use self-assembled DNA, single-molecule localization microscopy, and finite difference time domain electromagnetic simulations to measure, describe and reconstruct sub-diffraction limited shifts in the projection of plasmon-coupled fluorophores. This will let us pave the way to the design of a magnifying device aimed at visualizing densely packed biological structures. Fundamental understanding of plasmonic coupling obtained in this project will be directly applicable in various fields of research by providing a tool for high-resolution visualization of molecular structures and their dynamics in the form of plasmonic assemblies, and enabling precise control over enhancement in fluorescence and Raman systems.