Nano Chemistry - Laursen Group

Laursen Group

Design and synthesis of fluorescent dyes, self-assembly of molecular materials, Spectroscopy, and applications of fluorescent dyes and materials.

Our research concerns the design and synthesis on fluorescent dyes and molecular materials with new and improved optical properties. Our aim is to understand the relations between molecular structure and optical properties (molecular photophysics), and to use this insight to tailor dyes and materials to be used e.g. in: fluorescent probes and sensors, cell imaging, fluorescence guided surgery, ultra-bright crystals and nanoparticles, organic laser materials and other optical materials applications. In the group we focus on design, synthesis and spectroscopy, and we collaborate with a broad range of physicists, biologists, medical researches, other nanoscience and chemistry groups about the applications and properties of our materials.

Research

Currently our research is focused in the three main areas outlined below. Furthermore, we take part in many collaborative projects contributing our dyes and materials or our spectroscopic capacity on systems synthesized by collaborators.

Triangulenium dyes

Triangulenium dyes are carbenium ions of exceptional chemical stability, and broad structural diversity owing to the facile synthetic routes developed over the years. We constantly explore new transformations and structural motifs to expand our toolbox of dyes with unique optical properties.

Recent examples of dye development include:

Photophysics and applications of dyes

The high photo-stability and unique long fluorescence lifetime of the aza/oxa-triangulenium dyes (10-20 ns) provides attractive opportunities in time-resolved imaging and sensing, anisotropy assays and for PET base fluorescent probes/sensors. Some recent examples of such dye applications include:

Fluorescent molecular materials and nanostructures:

When organic dyes pack close together in solid state materials or aggregates/nanostructures their optical properties are most often dramatically changed due to electronic coupling between the transition moments, which both gives reis to new optical transition and efficient energy migration in the nanostructures. We are interested in understanding these processes and to develop methods that allow us to organize the dyes in specific structures and thus control the properties.

Recently we have in particular worked with an efficient supramolecular self-assembly approach to organize cationic dyes in solid state materials by use of the anion binding macrocycle cyanostar. In the resulting “SMILES” materials the dyes are isolated and retain their intrinsic molecular properties and produces ultra-bright crystals, thin-films, polymer blends and nanoparticles. This work is done in close collaboration with the Flood group at Indiana University. Some recent work on SMILES and dye materials includes: