The browser you are using is not supported by this website. All versions of Internet Explorer are no longer supported, either by us or Microsoft (read more here: https://www.microsoft.com/en-us/microsoft-365/windows/end-of-ie-support).

Please use a modern browser to fully experience our website, such as the newest versions of Edge, Chrome, Firefox or Safari etc.

Yanmei He. Portrait.

Yanmei He

Postdoctoral fellow

Yanmei He. Portrait.

A DNA‐Stabilized Ag₁₈¹²+ Cluster with Excitation‐Intensity‐Dependent Dual Emission

Author

  • Vanessa Rück
  • Mikkel B. Liisberg
  • Christian Brinch Mollerup
  • Yanmei He
  • Junsheng Chen
  • Cecilia Cerretani
  • Tom Vosch

Summary, in English

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 DNA2[Ag18]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 DNA2[Ag18]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 DNA2[Ag18]12+. We, therefore, speculate that the ratiometric excitation intensity response could be the result of optically activated delayed fluorescence.

Department/s

  • LU Profile Area: Light and Materials
  • LTH Profile Area: Nanoscience and Semiconductor Technology
  • Chemical Physics
  • NanoLund: Centre for Nanoscience

Publishing year

2023-08-14

Language

English

Publication/Series

Angewandte Chemie - International Edition

Volume

62

Issue

39

Document type

Journal article

Publisher

John Wiley & Sons Inc.

Topic

  • Physical Chemistry (including Surface- and Colloid Chemistry)
  • Atom and Molecular Physics and Optics

Status

Published

ISBN/ISSN/Other

  • ISSN: 1433-7851