Regensburg 2007 – wissenschaftliches Programm
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BP: Fachverband Biologische Physik
BP 18: Functionalized Nanoparticles
BP 18.1: Vortrag
Mittwoch, 28. März 2007, 14:00–14:15, H43
Phosphorescence quenching in the vicinity of gold nanoparticles — •Thomas Soller1, Moritz Ringler1, Thomas Arno Klar1, Jochen Feldmann1, Michael Wunderlich2, Yvonne Markert2, Hans-Peter Josel2, Alfons Nichtl2, and Konrad Kürzinger2 — 1Photonics and Optoelectronics Group, Department of Physics and CeNS, Ludwig-Maximilians-Universität München — 2Roche Diagnostics GmbH, Nonnenwald 2, Penzberg
Gold nanoparticles alter the radiative and nonradiative decay rates of nearby dye molecules, resulting either in a decreased or increased luminescence intensity. While the effects of gold nanoparticles on surrounding fluorophores have been investigated thoroughly, there are no corresponding studies dealing with the influence of gold nanoparticles on the luminescent properties of phosphors. Especially for applications in biosensing, phosphors are particularly suitable, as they allow to cut off autofluorescence.
We have investigated the influence of gold nanoparticles on the radiative and nonradiative decay rates of two different phosphorescent dyes. The phosphors are attached to the nanoparticles via a biomolecular recognition reaction. Time-resolved luminescence spectroscopy reveals an increase of the radiative as well as the nonradiative rate in all regarded phosphor/gold nanoparticle hybrid systems. The increase in the radiative rate is outweighed by the more prominent enhancement in the nonradiatve rate, thus a luminescence quenching occurs.