More Like this

1. Tug-of-War between DNA Chelation and Silver Agglomeration in DNA–Silver Cluster Chromophores

   https://doi.org/10.1021/acs.jpcb.2c01054  

   Petty, Jeffrey T. ; Lewis, David ; Carnahan, Savannah ; Kim, Dahye ; Couch, Caroline ( June 2022 , The Journal of Physical Chemistry B)
2. A hybrid lipid membrane coating “shape-locks” silver nanoparticles to prevent surface oxidation and silver ion dissolution

   https://doi.org/10.1039/D0RA01727B  

   Miesen, Thomas J. ; Engstrom, Arek M. ; Frost, Dane C. ; Ajjarapu, Ramya ; Ajjarapu, Rohan ; Lira, Citlali Nieves ; Mackiewicz, Marilyn R. ( April 2020 , RSC Advances)

   null (Ed.)

   The controlled synthesis of stable silver nanoparticles (AgNPs), that do not undergo surface oxidation and Ag + ion dissolution, continues to be a major challenge. Here the synthesis of robust hybrid lipid-coated AgNPs, comprised of l -α-phosphatidylcholine (PC) membranes anchored by a stoichiometric amount of long-chained hydrophobic thiols and sodium oleate (SOA) as hydrophobic binding partners, that do not undergo surface oxidation and Ag + ion dissolution, is described. UV-Visible (UV-Vis) spectroscopy, transmission electron microscopy (TEM), and inductively coupled plasma mass spectrometry (ICP-MS) demonstrate that in the presence of strong oxidants, such as potassium cyanide (KCN), the hybrid lipid-coated AgNPs are stable and do not undergo surface oxidation even in the presence of membrane destabilizing surfactants. UV-Vis studies show that the stability of hybrid lipid-coated AgNPs of various sizes and shapes is dependent on the length of the thiol hydrocarbon chain and can be ranked in the order of increasing stability as follows: propanethiol (PT) < hexanethiol (HT) ≤ decanethiol (DT). UV-Vis and ICP-MS studies show that the hybrid lipid-coated AgNPs do not change in size or shape confirming that the AgNPs do not undergo surface oxidation and Ag + ion dissolution when placed in the presence of strong oxidants, chlorides, thiols, and low pH. Long-term stability studies, over 21 days, show that the hybrid lipid-coated AgNPs do not release Ag + ions and are more stable. Overall, these studies demonstrate hybrid membrane encapsulation of nanomaterials is a viable method for stabilizing AgNPs in a “shape-locked” form that is unable to undergo surface oxidation, Ag + ion release, aging, or shape conversion. More importantly, this design strategy is a simple approach to the synthesis and stabilization of AgNPs for a variety of biomedical and commercial applications where Ag + ion release and toxicity is a concern. With robust and shielded AgNPs, investigators can now evaluate and correlate how the physical features of AgNPs influence toxicity without the confounding factor of Ag + ions present in samples. This design strategy also provides an opportunity where the membrane composition can be tuned to control the release rate of Ag + ions for optimizing antimicrobial activity. 

   more » « less
3. A Split DNA Scaffold for a Green Fluorescent Silver Cluster

   https://doi.org/10.1021/acs.jpcc.9b03773  

   He, Chen ; Goodwin, Peter M. ; Yunus, Ahmed I. ; Dickson, Robert M. ; Petty, Jeffrey T. ( June 2019 , The Journal of Physical Chemistry C)
4. Beyond Nature’s base pairs: machine learning-enabled design of DNA-stabilized silver nanoclusters

   https://doi.org/10.1039/D3CC02890A  

   Mastracco, Peter ; Copp, Stacy M. ( July 2023 , Chemical Communications)

   Sequence-encoded biomolecules such as DNA and peptides are powerful programmable building blocks for nanomaterials. This paradigm is enabled by decades of prior research into how nucleic acid and amino acid sequences dictate biomolecular interactions. The properties of biomolecular materials can be significantly expanded with non-natural interactions, including metal ion coordination of nucleic acids and amino acids. However, these approaches present design challenges because it is often not well-understood how biomolecular sequence dictates such non-natural interactions. This Feature Article presents a case study in overcoming challenges in biomolecular materials with emerging approaches in data mining and machine learning for chemical design. We review progress in this area for a specific class of DNA-templated metal nanomaterials with complex sequence-to-property relationships: DNA-stabilized silver nan- oclusters (AgN-DNAs) with bright, sequence-tuned fluorescence colors and promise for biophotonics applications. A brief overview of machine learning concepts is presented, and high-throughput experimental synthesis and characterization of AgN-DNAs are discussed. Then, recent progress in machine learning-guided design of DNA sequences that select for specific AgN-DNA fluorescence properties is reviewed. We conclude with emerging opportunities in machine learning-guided design and discovery of AgN-DNAs and other sequence-encoded biomolecular nanomaterials. 

   more » « less
5. Heat, pH, and salt: synthesis strategies to favor formation of near-infrared emissive DNA-stabilized silver nanoclusters

   https://doi.org/10.1039/D3CC02896H  

   Guha, Rweetuparna ; Rafik, Malak ; Gonzàlez-Rosell, Anna ; Copp, Stacy M. ( July 2023 , Chemical Communications)

   We present chemical synthesis strategies for DNA-stabilized silver nanoclusters (AgN-DNAs) with near-infrared (NIR) emission in the biological tissue transparency windows. Elevated temperatures can significantly increase chemical yield of near-infrared nanoclusters. In most cases, basic pH favors near-infrared nanoclusters while micromolar amounts of NaCl inhibit their formation. 

   more » « less