Role of Ligand Coordination Geometry in Controlling Binding of Thiolated Target Molecules to Quantum Dot Surfaces

by Heyes, Colin D.

Various coordinating ligand geometries have been used to control the soly. and reactivity of nanoparticles, particularly for bioconjugation applications. However, binding of target mols. and ligand exchange mechanisms have not been systematically studied as a function of the different coordination geometries. We study these effects by modifying a near IR dye to serve as a highly-sensitive reporter for studying binding mechanisms of thiolated target mols. to quantum dots (QDs) by fitting the adsorption profiles to the Hill equation. Energy transfer studies from the QD to the dye mols. at the ensemble and single particle level were used to follow the statistical distribution of dyes across the QD sample to probe heterogeneity. These results highlight that binding mechanisms of target mols. strongly depend on the dentate nature of the ligands. Implications of these results in various fields of nanoscience will be discussed.