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Chloride Ligands on DNA-Stabilized Silver Nanoclusters.
Anna Gonzàlez-Rosell1, Sami Malola2, Rweetuparna Guha1
1Department of Materials Science and Engineering, University of California, Irvine, California 92697, United States.
Journal of the American Chemical Society
|May 8, 2023
Summary
DNA-stabilized silver nanoclusters (AgN-DNAs) can incorporate chloride ligands, enhancing their stability in biological conditions. This discovery expands the structural diversity and applications of AgN-DNAs in biophotonics.
Area of Science:
- Nanomaterials Science
- Biophysical Chemistry
- Structural Biology
Background:
- DNA-stabilized silver nanoclusters (AgN-DNAs) are typically characterized by DNA oligomer ligands.
- Previous studies assumed one or two DNA ligands per nanocluster.
Purpose of the Study:
- To investigate the presence of additional ligands in AgN-DNAs.
- To characterize the structure and stability of chloride-containing AgN-DNAs.
- To explore the implications for biophotonics applications.
Main Methods:
- Mass spectrometry of isolated AgN-DNA species.
- X-ray crystallography reanalysis.
- Density Functional Theory (DFT) calculations.
- UV-vis absorption spectroscopy.
- 35Cl-nuclear magnetic resonance (NMR) spectroscopy.
- High-throughput screening.
Main Results:
- Identification of chloride ligands in AgN-DNAs, with molecular formulas (DNA)2[Ag16Cl2]8+.
- Chloride ligands enhance stability in biologically relevant chloride concentrations.
- Chloride-ligand exchange for bromides red-shifts optical spectra.
- DFT calculations confirm chloride stability and spectral properties.
- Reanalysis of X-ray structures confirms chloride presence, previously misidentified as silver.
- Discovery of additional chloride-containing AgN-DNA via high-throughput screening.
Conclusions:
- Chloride ligands are integral components of certain AgN-DNAs, not just DNA.
- The presence of chloride ligands significantly enhances nanocluster stability in saline environments.
- This finding opens new avenues for tailoring AgN-DNA properties for biophotonics.
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