Dresden 2009 – wissenschaftliches Programm
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BP: Fachverband Biologische Physik
BP 11: Novel Methods
BP 11.6: Vortrag
Dienstag, 24. März 2009, 15:45–16:00, ZEU 260
Immunoassay based on long-range fluorescence quenching by gold nanoparticles — •Meike Kloster1, Sergiy Mayilo1, Fernando Stefani1, Michael Wunderlich1, Thomas A. Klar1,2, Hans-Peter Josel3, Dieter Heindl3, Alfons Nichtl3, Konrad Kürzinger3, and Jochen Feldmann1 — 1Photonics and Optoelectronics Group, Department of Physics and CeNS, Ludwig-Maximilians-Universität München, Munich, Germany — 2Institute of Physics and Institute of Micro- and Nanotechnologies, Technical University of Ilmenau, Ilmenau, Germany — 3Roche Diagnostics GmbH, Penzberg, Germany
Förster energy transfer is a common tool for the detection of biomolecules. However, due to its short-range, the application is limited to small distances. Energy transfer from a dye molecule to a gold nanoparticle (AuNP) is effective over longer distances due to the larger cross-section of the particles and to radiative rate suppression [1]. Here we use the long-range fluorescence quenching by AuNPs to develop a novel immunoassay for a diagnostically relevant example: troponin T (TnT), an indicator of damage to the heart muscle. AuNPs and fluorescent dyes are functionalized with anti-TnT antibodies. In the presence of TnT, the AuNPs and the fluorophores are brought together by their specific interaction leading to fluorescence quenching. By using time-resolved spectroscopy, the contributions of direct energy transfer and radiative decay suppression to fluorescence quenching are quantified.
[1] E. Dulkeith et al., Nano Letters 5, 585 (2005)