Dresden 2003 – wissenschaftliches Programm

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CPP: Chemische Physik und Polymerphysik

CPP 2: Colloide, Nanopartikel und Kapseln

CPP 2.5: Vortrag

Montag, 24. März 2003, 11:15–11:30, ZEU/260

Fluorescence quenching in the vicinity of gold nanoparticles — •E. Dulkeith¹, T.A. Klar¹, S. Kowarik¹, A.C. Morteani¹, T. Niedereichholz¹, S. Levi², F.C.J.M. van Veggel², D.N. Reinhoudt², M. Möller³, D.I. Gittins⁴, and J. Feldmann¹ — ¹Photonics and Optoelectronics Group, Sektion Physik and CeNS, University of Munich — ²Lab. for Supramol. Chem and Tech., University of Twente, The Netherlands — ³Abt. Org. Chem. III, University of Ulm, 89069 Ulm, Germany — ⁴MPI of Colloids and Interfaces, Potsdam

Composite systems of dye molecules and metal nanoparticles have gained considerable interest in materials science as well as in biophotonics. The fluorescence decay of dye molecules, chemically attached to gold nanoparticles of different sizes, has been investigated as a function of the particle radius. Already the smallest nanoparticles of only 2 nm diameter quench 99.8% of the original fluorescence signal. Time resolved fluorescence measurements are carried out using a streak camera. These measurements reveal that both, a change of the radiative and of the nonradiative rate contribute to the drastic fluorescence quenching. Assuming resonant energy transfer and a phase shift between the molecular and the metal dipole being responsible for these two effects, respectively, we compare our experimental findings with theoretical results derived from the Gersten-Nitzan model.

[1] E. Dulkeith et al. Phys. Rev. Lett. 89, 203002 (2002)