Eur. Phys. J. D 43, 275-278 (2007)
https://doi.org/10.1140/epjd/e2007-00118-5

Optical absorption of isolated silver cluster-tryptophan: A joint experimental and theoretical study

¹ Laboratoire de Spectrométrie ionique et moléculaire, UMR 5579, Université Lyon I and CNRS, 43 Bd du 11 novembre 1918, 69622 Villeurbanne Cedex, France
² Humboldt-Universität zu Berlin, Institut für Chemie, Brook-Taylor-Straße 2, 12489 Berlin, Germany

Corresponding author: ^a vbk@chemie.hu-berlin.de

Received: 30 August 2006
Published online: 24 May 2007

Abstract

We present a joint experimental and theoretical gas phase study of photoabsorption and photofragmentation of silver cluster-biomolecule complexes. We demonstrate on the example of [ Trp.Ag₃] ⁺ that binding of the metal cluster to a biomolecule leads to a significant enhancement of the photoabsorption in comparison with [Trp.H]⁺ and [Trp.Ag]⁺. This enhancement arises due to the coupling between the excitations in the metallic subunit with charge transfer excitations between silver cluster and tryptophan. Our experimental studies show that silver clusters up to eleven atoms can be bound to tryptophan and we present first results on the photofragmentation of the Trp.Ag₁₁⁺ complex cation, in which properties of cluster subunit remain preserved.