title: Fluorescence properties of hydrophilic semiconductor nanoparticles with tridentate polyethylene oxide ligands.
abstract: In this contribution a facile, one-step synthesis of tridentate thiol-functionalized PEO ligands and their ability to stabilize CdSe/CdS/ZnS core-shell-shell nanoparticles in aqueous media are described. The PEO-coated quantum dots show colloidal stability as well as preserved fluorescence even at very low concentrations of a few nM. For improved ligand attachment and enhanced fluorescence properties a method for ligand exchange was developed, which includes formation of a ligand zinc complex before the actual exchange reaction. The stability and fluorescence properties in various aqueous buffers and cell media and at pH values down to pH 3 were investigated. The firm binding of the tridentate ligands to the particle surface makes this ligand-particle system a promising tool for biological applications. In addition, activation of the ligands' terminal hydroxyl group for covalent biofunctionalization by esterification with succinic acid is reported.
authors: Institute for Physical Chemistry, University of Hamburg, Grindelallee 177, 20146 Hamburg, Germany.
authors: Marc
authors: M
authors: Thiry
authors: Klaus
authors: K
authors: Boldt
authors: Marija S
authors: MS
authors: Nikolic
authors: Florian
authors: F
authors: Schulz
authors: Michael
authors: M
authors: Ijeh
authors: Andjana
authors: A
authors: Panicker
authors: Tobias
authors: T
authors: Vossmeyer
authors: Horst
authors: H
authors: Weller