Regensburg 2010 – wissenschaftliches Programm

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BP: Fachverband Biologische Physik

BP 13: Nanoparticles and Viruses

BP 13.5: Vortrag

Dienstag, 23. März 2010, 15:30–15:45, H45

Excited state energy transfer between CdSe nanocrystals and the isolated phycobiliprotein antenna of A.marina — •Franz-Josef Schmitt¹, Vithiya Jeyasangar¹, Heinrich Südmeyer¹, Max Schoengen¹, Vladimir Paschenko³, Hans Joachim Eichler¹, and Gernot Renger² — ¹Institute of Optics and Atomic Physics, Berlin Institute of Technology — ²Max-Vollmer Laboratory for Biophysical Chemistry, Berlin Institute of Technology — ³Lomonosov Moscow State University

A quantitative analysis of the interaction between semiconductor nanocrystals and isolated light harvesting complexes from photosynthetic organisms is of relevance for the development of biosensors with enhanced sensitivity. The present work describes results obtained on a hybrid system consisting of CdSe nanoparticles and rod shaped phycobiliproteine (PBP) antenna complexes from the cyanobacterium Acaryochloris marina. The CdSe core of the nanocrystals is covered with a ZnS shell and the surface is functionalised with anions of dihydrolipoic acid leading to electrostatic coupling to the PBPs. The measured time resolved and time integrated fluorescence spectra can be explained by a highly efficient excitation energy transfer from the nanocrystals to the PBP antenna with a time constant of about 200 ps at room temperature. At 0°C a decoupling of about 80 % of the CdSe crystals from the PBP antennae was observed. These results could be relevant for the design of switchable light harvesting systems or controlled fluorescence enhancement.