Petrakova Group

Nanoengineering of light.

We are interested in how structural organization of molecules and materials at the nanoscale drives their response to light. We are developing a new method for spatial manipulation of light at the nanoscale by assembly of plasmonic nanostructures. We aim to use this method to advance visualization of densely packed biomolecules and their dynamics. Part of our journey is dedicated to improving algorithms used by single-molecule microscopy methods and to making new types of fluorophores that are bright and do not bleach.

Metal nanostructures are capable of massive enhancements of optical response, which arise from collective electromagnetic resonances called plasmons. The interaction of a fluorophore and a plasmonic structure strongly increases the number of emitted photons. Recently emerging methods of superresolution microscopy allowed to discover previously inaccessible aspects of plasmonic enhancement. It appears that besides the increase in number of emitted photons, plasmonic enhancement also affects the projected position and direction of the fluorophore-emitted photons in surprising and puzzling ways. We are studying how to control these shifts by altering the enhancement mechanism, fluorophore-plasmon distance, and their dynamics.

We combine methods from different fields

Nanoscale self-assembly

We are using DNA self assembly to position fluorophores and plasmonic nanostructures at defined distances.

Superresolution microscopy

Single molecule localization microscopy enables us to study the shifts in the direction of emission below the diffraction limit.

Machine learning

We use machine learning to describe and reconstruct sub-diffraction limited shifts in the projection of plasmon-coupled fluorophores.