A DNA-Stabilized Ag 18 12+ Cluster with Excitation-Intensity-Dependent Dual Emission.

Autor: Rück V; Department of Chemistry, University of Copenhagen, Universitetsparken 5, 2100, Copenhagen, Denmark., Liisberg MB; Department of Chemistry, University of Copenhagen, Universitetsparken 5, 2100, Copenhagen, Denmark., Mollerup CB; Department of Forensic Medicine, University of Copenhagen, Frederik V's Vej 11, 2100, Copenhagen, Denmark., He Y; Division of Chemical Physics and NanoLund, Lund University P.O. Box 124, 22100, Lund, Sweden., Chen J; Department of Chemistry, University of Copenhagen, Universitetsparken 5, 2100, Copenhagen, Denmark., Cerretani C; Department of Chemistry, University of Copenhagen, Universitetsparken 5, 2100, Copenhagen, Denmark., Vosch T; Department of Chemistry, University of Copenhagen, Universitetsparken 5, 2100, Copenhagen, Denmark.
Jazyk: angličtina
Zdroj: Angewandte Chemie (International ed. in English) [Angew Chem Int Ed Engl] 2023 Sep 25; Vol. 62 (39), pp. e202309760. Date of Electronic Publication: 2023 Aug 22.
DOI: 10.1002/anie.202309760
Abstrakt: DNA-stabilized silver nanoclusters (DNA-AgNCs) are easily tunable emitters with intriguing photophysical properties. Here, a DNA-AgNC with dual emission in the red and near-infrared (NIR) regions is presented. Mass spectrometry data showed that two DNA strands stabilize 18 silver atoms with a nanocluster charge of 12+. Besides determining the composition and charge of DNA 2 [Ag 18 ] 12+ , steady-state and time-resolved methods were applied to characterize the picosecond red fluorescence and the relatively intense microsecond-lived NIR luminescence. During this process, the luminescence-to-fluorescence ratio was found to be excitation-intensity-dependent. This peculiar feature is very rare for molecular emitters and allows the use of DNA 2 [Ag 18 ] 12+ as a nanoscale excitation intensity probe. For this purpose, calibration curves were constructed using three different approaches based either on steady-state or time-resolved emission measurements. The results showed that processes like thermally activated delayed fluorescence (TADF) or photon upconversion through triplet-triplet annihilation (TTA) could be excluded for DNA 2 [Ag 18 ] 12+ . We, therefore, speculate that the ratiometric excitation intensity response could be the result of optically activated delayed fluorescence.
(© 2023 The Authors. Angewandte Chemie International Edition published by Wiley-VCH GmbH.)
Databáze: MEDLINE
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