Berlin 2012 – wissenschaftliches Programm

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BP: Fachverband Biologische Physik

BP 10: Biopolymers and Biomaterials (with CPP)

BP 10.3: Vortrag

Dienstag, 27. März 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.