The Center for Nano- and Biophotonics sets up research lines in the area of nanoparticles, microlaser technology and optical switches, biosensors, bio-spectroscopy, scanning of biomaterials, electro-optical particle manipulation and active nanophotonic implants.
This project aims at a comprehensive view on the physicochemistry of nanocrystal-ligand systems. For this
purpose, we will develop the potential of solution NMR as an in-situ characterization tool for nanocrystal
ligands to answer a number of pertinent questions regarding colloidal quantum dots. This concerns the nature
and the number of ligands, problems of ligand exchange, the binding strength of ligands and the way ligands
may affect the materials properties of quantum dots. The project consists of four parts. (1) Extending the
number of systems studied and described by solution NMR to verify the existing classification based on
exchange rate and to extend it to intermediate cases. (2) Analyzing the dynamics of ligands, more specific the
exchange between bound and free ligands and the local freedom of motion of bound ligands. (3) Determining
the relative binding strength of different ligands, including the role of the functional head group and the ligand
chain length but also the presumed selectivity of specific ligands for particular crystal planes. (4) Combining
NMR results with data obtained by other characterization techniques to complement NMR information on
nanocrystal-ligand systems in terms of surface composition and the ligand-nanocrystal bond and the link
between ligands and quantum dot luminescence.