title: Characterization of the organic ligand shell of semiconductor quantum dots by fluorescence quenching experiments.
abstract: We present the characterization of the organic ligand shell of CdSe/Cd(x)Zn(1-x)S/ZnS nanoparticles by means of fluorescence quenching experiments. Both electron scavengers and acceptors for resonance energy transfer were employed as probes. Different quenching behavior for short and long chain thiol ligands in water was found. It could be shown that poly(ethylene oxide) (PEO)-capping of the particles comprises a densely packed inner shell and a loosely packed outer shell in which ions and small molecules diffuse unhindered. A quantitative uptake of quencher molecules into the PEO shell was observed, through which the particle volume including the ligand sphere could be determined.
authors.affiliation: Institute for Physical Chemistry, University of Hamburg, Grindelallee 177, 20146 Hamburg, Germany.
authors.forename: Klaus
authors.initials: K
authors.lastname: Boldt
authors.forename: Sebastian
authors.initials: S
authors.lastname: Jander
authors.forename: Kathrin
authors.initials: K
authors.lastname: Hoppe
authors.forename: Horst
authors.initials: H
authors.lastname: Weller
mesh_terms: D003545:Cysteine / Q000737:chemistry; D004579:Electron Transport; D031541:Fluorescence Resonance Energy Transfer; D008024:Ligands; D009930:Organic Chemicals / Q000737:chemistry*; D011092:Polyethylene Glycols / Q000737:chemistry; D045663:Quantum Dots; D012666:Semiconductors; D014867:Water / Q000737:chemistry
chemical_list: D008024:Ligands; D009930:Organic Chemicals; D014867:Water; D011092:Polyethylene Glycols; D003545:Cysteine