Single Molecule Detection
The group develops analysis techniques allowing to monitor spatially resolved dynamical properties. This allows to characterize anisotropic motion of single dye molecules in heterogeneous environments and opens the way to correlate structure and dynamics at chemically heterogeneous surfaces.
In detail the group is interested in the
• anisotropic single molecule dynamics in liquid crystals
• heterogeneous dynamics of single molecule in polymers
Anisotropic Single Molecule Diffusion in Liquid Crystals
Liquid crystals are liquid materials with an long range orientational order of the molecules. This long range orientational order results in anisotropic optical properties, which are exploited in liquid crystalline displays. In addition to the anisotropic optical properties the transport properties such as molecular diffusion and heat transport become ansitropic as well but are much less well explored on the nanoscale. The group studies single molecule diffusion as well as local anisotropic light propagation in liquid crystalline materials and wide-field fluorescence microscopy. The dynamics at domain boundaries is of special interest.
Single Molecule Dynamics in Polymers
The heterogeneous dynamics of polymers close to the glass transition is still one of the major unsolved problems in soft matter physics. The arrest of molecular dynamics in amorphous systems has been explored by various ensemble techniques resulting in different answers on th existence of dynamic and spatial heterogeneities. We explore the heterogeneous dynamics in polymers by single molecule fluorescence spectroscopy and compare the results to dielectric spectroscopy. Special interest is in the correlated motion of dye molecule in close viscinity and their coupling to the polymer environment.