Impact of Ligand Structure on Biological Activity and Photophysical Properties of NHC-Protected Au<sub>13</sub> Nanoclusters
N-heterocyclic carbene (NHC)-protected gold nanoclusters display high stability and high photoluminescence, making them well-suited for fluorescence imaging and photodynamic therapeutic applications. We report herein the synthesis of two bisNHC-protected Au<sub>13</sub> nanoclusters with π-extended aromatic systems. Depending on the position of the π-extended aromatic system, changes to the structure of the ligand shell in the cluster are observed, with the ability to correlate increases in rigidity with increases in fluorescence quantum yield. Density functional theory analysis reveals that both synthesized Au<sub>13</sub> nanoclusters are 8-electron superatoms but have distinct differences in the characteristics of the lowest unoccupied single-electron states. Qualitatively, this implies different mechanisms for excitations and their decay over the fundamental energy gap. Stability and photophysical studies were carried out to provide the emission lifetime and optical purity of the two clusters. Active intracellular uptake of the nanoclusters was confirmed in vitro using confocal microscopy in human epithelial carcinoma cells. Reactive oxygen species production was measured at 7% efficiency. The high cluster stability, photoluminescence quantum yields, and efficient cellular uptake in cancer cells suggest potential for these nanoclusters as highly efficient and tunable nanomedical platforms.
Authors
- Kristen Harrington
- Tatsuya Tsukuda (ORCID: https://orcid.org/0000-0002-0190-6379)
- Lili Ding (ORCID: https://orcid.org/0000-0002-4831-3300)
- Hannu Häkkinen (ORCID: https://orcid.org/0000-0002-8558-5436)
- Tetyana I. Levchenko (ORCID: https://orcid.org/0000-0002-1883-9221)
- Kevin G. Stamplecoskie (ORCID: https://orcid.org/0000-0002-0232-9956)
- Cathleen M. Crudden (ORCID: https://orcid.org/0000-0003-2154-8107)
- Emily Steele
- Nahyun Kwon (ORCID: https://orcid.org/0000-0003-2442-5532)
- Viveka K. Kulkarni (ORCID: https://orcid.org/0000-0002-4383-2021)
- Shinjiro Takano (ORCID: https://orcid.org/0000-0001-9262-5283)
- Masakazu Nambo (ORCID: https://orcid.org/0000-0003-0153-3178)
- Gang Zheng (ORCID: https://orcid.org/0000-0002-0705-7398)
- Emily L. Albright (ORCID: https://orcid.org/0000-0002-3679-1911)
- Juan Chen (ORCID: https://orcid.org/0000-0001-7515-5072)
- Sami Malola
- Elham Zeinizade
Institutions
- University Health Network (CA)
- University of Toronto (CA)
- Queen's University (CA)
- Center for NanoScience (DE)
- Princess Margaret Cancer Centre (CA)
- Health Net (US)
- Centre de Nanosciences et de Nanotechnologies (FR)
- Nano Carbon (Poland) (PL)
- Nagoya University (JP)
- The University of Tokyo (JP)
- Graduate School USA (US)
- University of Jyväskylä (FI)
Publication Details
- Journal
- Journal of the American Chemical Society
- Published
- 2025-01-22
- DOI
- https://doi.org/10.1021/jacs.4c12072
- Citations
- 26
- Primary Topic
- Nanocluster Synthesis and Applications
- Type
- article
- Field-Weighted Citation Impact
- 13.46
Funders
- Government of Ontario
- Canada Foundation for Innovation
- Japan Science and Technology Corporation
- Canada Research Chairs
- Nagoya University
- Research Foundation for the Electrotechnology of Chubu
- American Chemical Society Petroleum Research Fund
- Natural Sciences and Engineering Research Council of Canada
- Social Sciences and Humanities Research Council of Canada
- Japan Society for the Promotion of Science