The Single Molecule Spectroscopy Group in the Chemical Physics Department at the University of Lund recently has developed 2D polarisation single-molecule spectroscopy, a method which measures a two dimensional function that describes the fluorescence intensity and polarization of a single object as a function of the electric field‘s direction of the linearly polarized excitation light, and which enables for quantitative characterization of the excitation energy transfer in the studied objects ranging from single molecules to bulk films. This is very suitable to extend the understanding of processes ocurring in single molecules or in films. Since the method can be applied on single molecules as well as on films, it can be further used to investigate the concentration dependence of the processes of interest.
The method was successfully used to study thin films of a solar cell material, and is being tested on cell cultures and histological samples. The energy transfer sensitivity of our imaging technique also opens exciting applications in life sciences for the study of biologically relevant systems, such as the aggregation of proteins involved in the causes of various diseases. Besides 2D polarisation single-molecule spectroscopy, the group uses time-resolved single molecule spectroscopy, and has simulated conjugated polymer chain conformations.