SPEAKER PROFILE |
 Dr. Sophie Brasselet Institut Fresnel, CNRS, Aix Marseille Université France |
Imaging ultrastructure in nanomaterials and biomaterials by polarized microscopy
Abstract
Fluorescence to nonlinear coherent optical microscopy can reveal important spatial properties in nanomaterials, cells and biological tissues from fixed situations to in vivo dynamics. While microscopy can guide interpretation through morphological observations at the sub-micrometric scale, optical imaging cannot directly access the way molecules are organized in specific ultrastructures, occuring at the molecular scale. This property, which is important in many fields, from nanomaterials engineering to biomechanics, is today most often studied using electron microscopy or X ray diffraction, which are not compatible with real time imaging.
We will show that reporting molecular organization in biological samples down to the nano scale is made possible using fluorescence polarization resolved optical microscopy, which takes advantage of the orientation-sensitive coupling between optical excitation fields and molecular transition dipole moments. This approach, which can be extended to super resolution microscopy, has revealed ultrastructural imaging capabilities in the cell cytoskeleton. We will finally describe how polarized imaging can be applied to nonlinear optical imaging in nanostructures, revealing nanoscale plasmonic vectorial properties in metal nanostructures and structrural heterogeneities in dielectric nanoparticles.
We will show that reporting molecular organization in biological samples down to the nano scale is made possible using fluorescence polarization resolved optical microscopy, which takes advantage of the orientation-sensitive coupling between optical excitation fields and molecular transition dipole moments. This approach, which can be extended to super resolution microscopy, has revealed ultrastructural imaging capabilities in the cell cytoskeleton. We will finally describe how polarized imaging can be applied to nonlinear optical imaging in nanostructures, revealing nanoscale plasmonic vectorial properties in metal nanostructures and structrural heterogeneities in dielectric nanoparticles.
Bio
Sophie Brasselet is an optical physicist. She obtained her Ph.D in 1997 at University Paris-Sud, France on nonlinear optical properties of polymers and spent a two years postdoc at UCSD (1998) and Stanford University (1999) in the USA, developing single fluorescent molecules imaging in cells. After six years at ENS Cachan, France, as an assistant professor developing nonlinear microscopy methods, she is now working as a research director at Institute Fresnel, Marseille, France. For the last fifteen years, she has developed novel nonlinear, fluorescence microscopy and super-resolution optical tools based on polarized light, dedicated to nanomaterials and biomolecular structural imaging. The methods she pioneered, based on the manipulation of light polarization in microscopy, are today applicable down to the single particle or single molecule scale.