Regensburg 2004 – wissenschaftliches Programm
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AKB: Biologische Physik
AKB 50: Poster Session "Biological Physics"
AKB 50.12: Poster
Freitag, 12. März 2004, 10:30–13:00, B
Fluorescence intermittency of single CdSe/ZnS quantum dots: A comparison between organic and water soluble ligand shells. — •Andrei Yu. Kobitski1, Colin D. Heyes1, Vladimir V. Breus1, Kirill V. Anikin1, and G. Ulrich Nienhaus1,2 — 1Department of Biophysics, University of Ulm, D - 89069 Ulm, Germany — 2Department of Physics, University of Illinois Urbana-Champaign, Urbana, IL 61801, USA
Recently, chemically synthesized quantum dots (QDs) are becoming widely used as fluorescent labels in biophysical and life-science research. The procedure of preparing organic soluble CdSe/ZnS core/shell QDs has become well established over the last 10 years and reproducibly gives monodisperse nanocrystals with high emission quantum yields of up to 50%. However, the procedure of water solubilization of the particles, which is needed for bio-related experiments, is not so well determined. Moreover, the blinking mechanism of water soluble QDs has not yet been systematically studied. In this work we present the study of single CdSe/ZnS QDs by means of Total Internal Reflection Fluorescence Microscopy (TIRFM). A comparison in blinking behavior of QDs with organic soluble Tri-n-octylphosphine oxide (TOPO) and water soluble mercaptoundecanoic acid (MUA) shells is performed.