Jump to main content
Jump to site search

Issue 44, 2018
Previous Article Next Article

Ultrafast fluorescence dynamics of DNA-based silver clusters

Author affiliations

Abstract

Atomic-level understanding of the nature of the electronically excited states in ligand-stabilized metal nanoclusters (NCs) is a prerequisite for the design of new NCs with desired properties. In this study, we investigate the emission dynamics of a Ag–DNA complex using the fluorescence up-conversion technique. We show that most of the relaxation from the Franck–Condon state to the emissive state takes place in less than 100 fs, in spite of a relatively large Stokes shift of 4500 cm−1. This relaxation is much faster than typical solvent/DNA relaxation rates. A further small relaxation occurs with time constants ranging from a few to hundreds of picoseconds. We also calculate the Stokes shift for model complexes of a small three-atom Ag3+ cluster with cytosine and guanine. The results of our calculations show that a substantial geometry change of the Ag3+ cluster is observed in the S1 state of both complexes, which results in Stokes shifts comparable with the experimental value. We conclude that the Stokes shift in the Ag–DNA complex arises mostly due to the change in the geometry of the Ag cluster in the excited state rather than to the solvent/DNA reorganization. Also, a different structure of the Ag–DNA complex (“dark cluster”), the excited state of which decays in 200 fs, is observed. The nature of this ultrafast deactivation is unclear, which requires further investigations.

Graphical abstract: Ultrafast fluorescence dynamics of DNA-based silver clusters

Back to tab navigation

Supplementary files

Publication details

The article was received on 10 Sep 2018, accepted on 11 Oct 2018 and first published on 11 Oct 2018


Article type: Paper
DOI: 10.1039/C8CP05727C
Citation: Phys. Chem. Chem. Phys., 2018,20, 28205-28210
  •   Request permissions

    Ultrafast fluorescence dynamics of DNA-based silver clusters

    Z. Reveguk, R. Lysenko, R. Ramazanov and A. Kononov, Phys. Chem. Chem. Phys., 2018, 20, 28205
    DOI: 10.1039/C8CP05727C

Search articles by author

Spotlight

Advertisements