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BP: Fachverband Biologische Physik
BP 10: Biopolymers and Biomaterials (with CPP)
BP 10.3: Talk
Tuesday, March 27, 2012, 10:15–10:30, H 1058
Excitation energy transfer processes in coupled phycobiliprotein complexes of A. marina and semiconductor nanocrystals forming hybrid structures — •Franz-Josef Schmitt1, Evgeny Maximov3, Patrick Hätti2, Vithiya Jeyasangar2, Jörn Weißenborn2, Vladimir Paschenko3, Hans Joachim Eichler2, Thomas Friedrich1, and Gernot Renger1 — 1Max Volmer Laboratory for Biophysical Chemistry — 2Institute of Optics and Atomic Physics, Berlin Institute of Technology, Germany — 3Department of Biophysics, M.V. Lomonosow Moscow State University, Russia
Pigment-protein complexes isolated from the photosynthetic apparatus provide functionally optimized nanoscaled devices for the construction of light driven operational units. The present work describes results obtained on hybrid systems consisting of CdSe quantum dots (QDs) with ZnS shell and different phycobiliproteins (PBPs) like hexameric phycoerythrin (PE), phycocyanin (PC), allophycocyanin (APC) and rod shaped PBP antenna complexes from the cyanobacterium Acaryochloris marina. The surface of the QDs is functionalised by covering with anionic and cationic groups leading to electrostatic contact with PBP. Excitation energy transfer (EET) from QDs to PBPs occurs with varying efficiency of up to 90 % for coupled QD/PBP hybrid complexes and is highly dependent on the temperature. The study with different QDs shows that the Förster Integral crucially determines the efficiency of EET while the electrostatic surface charge is of secondary relevance. Highly efficient EET and fluorescence enhancement of the acceptor was observed for particular stoichiometric ratios between QDs and PBPs.