ZB 10 - Soft Condensed Matter (R. Holyst)

A "wrap-and-wrest'' mechanism of fluorescence quenching of CdSe/ZnS quantum dots by surfactant molecules

Author(s): Kalwarczyk, Ewelina and Ziebacz, Natalia and Kalwarczyk, Tomasz and Holyst, Robert and Fialkowski, Marcin
Title: A "wrap-and-wrest'' mechanism of fluorescence quenching of CdSe/ZnS quantum dots by surfactant molecules
Abstract: We identified a mechanism of fluorescence quenching of CdSe/ZnS quantum (QDs) coated with two organic layers, octadecylamine and an polymer containing COOH groups, by nonionic (C12En) surfactants. The surfactant molecules by do not affect the fluorescence of the QDs. For the quenching occur, wrapping''} of the QDs by a bilayer of the surfactant is necessary. The formation of the bilayer causes an detachment (''}wresting''}) of the ligand molecules, by the creation of quenching sites on the QD surface. Due to two-stage nature, we refer to the quenching mechanism as the mechanism. The adsorption of the surfactant on the surface is a relatively slow process, occurring within minutes or Such long quenching times allowed monitoring surfactant progress in real time. The fluorescence signal decays and the decay time is inversely proportional to the surfactant concentration in solution.
Pages: 9908-9916
Journal: NANOSCALE
Volume: 5
ID: ISI:000325005500063
Year: 2013
DOI: 10.1039/c3nr03293k