TY - JOUR

T1 - A DNA-Stabilized Ag1812+ Cluster with Excitation-Intensity-Dependent Dual Emission

AU - Rück, Vanessa

AU - Liisberg, Mikkel B.

AU - Mollerup, Christian Brinch

AU - He, Yanmei

AU - Chen, Junsheng

AU - Cerretani, Cecilia

AU - Vosch, Tom

N1 - Funding Information: C. C., M. B. L., V. R. and T. V. acknowledge funding from the Villum Foundation (VKR023115), the Independent Research Fund Denmark (0136‐00024B) and the Novo Nordisk Foundation (NNF22OC0073734). Y. H. acknowledges the support from China Scholarship Council (No.202006150002). J. C. acknowledges support from the Novo Nordisk Foundation (NNF22OC0073582) and European Union's Horizon 2020 research and innovation programme under grant agreement No. 871124 Laserlab‐Europe. Publisher Copyright: © 2023 The Authors. Angewandte Chemie International Edition published by Wiley-VCH GmbH.

PY - 2023

Y1 - 2023

N2 - 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.

AB - 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.

KW - Excitation Intensity Probe

KW - Fluorescence

KW - Luminescence

KW - Optically Activated Delayed Fluorescence

KW - Silver Nanocluster

U2 - 10.1002/anie.202309760

DO - 10.1002/anie.202309760

M3 - Journal article

C2 - 37578902

AN - SCOPUS:85168623787

VL - 62

JO - Angewandte Chemie International Edition

JF - Angewandte Chemie International Edition

SN - 1433-7851

IS - 39

M1 - e202309760

ER -