title: Engineering the Structure and Properties of DNA-Nanoparticle Superstructures Using Polyvalent Counterions.
abstract: DNA assembly of nanoparticles is a powerful approach to control their properties and prototype new materials. However, the structure and properties of DNA-assembled nanoparticles are labile and sensitive to interactions with counterions, which vary with processing and application environment. Here we show that substituting polyamines in place of elemental counterions significantly enhanced the structural rigidity and plasmonic properties of DNA-assembled metal nanoparticles. These effects arose from the ability of polyamines to condense DNA and cross-link DNA-coated nanoparticles. We further used polyamine wrapped DNA nanostructures as structural templates to seed the growth of polymer multilayers via layer-by-layer assembly, and controlled the degree of DNA condensation, plasmon coupling efficiency, and material responsiveness to environmental stimuli by varying polyelectrolyte composition. These results highlight counterion engineering as a versatile strategy to tailor the properties of DNA-nanoparticle assemblies for various applications, and should be applicable to other classes of DNA nanostructures.
authors.affiliation: Institute of Biomaterials and Biomedical Engineering, Rosebrugh Building , Room 407, 164 College Street, Toronto, Ontario M5S 3G9, Canada.
authors.forename: Leo Y T
authors.initials: LY
authors.lastname: Chou
authors.affiliation: Institute of Biomaterials and Biomedical Engineering, Rosebrugh Building , Room 407, 164 College Street, Toronto, Ontario M5S 3G9, Canada.
authors.forename: Fayi
authors.initials: F
authors.lastname: Song
authors.affiliation: Institute of Biomaterials and Biomedical Engineering, Rosebrugh Building , Room 407, 164 College Street, Toronto, Ontario M5S 3G9, Canada.|Terrence Donnelly Centre for Cellular and Biomolecular Research, University of Toronto , 160 College Street, Room 230, Toronto, Ontario M5S 3E1, Canada.|Department of Chemical Engineering, University of Toronto , 200 College Street, Toronto, Ontario M5S 3E5, Canada.|Department of Chemistry, University of Toronto , 80 St George Street, Toronto, Ontario M5S 3H6, Canada.|Department of Material Science and Engineering, University of Toronto , Wallberg Building, 184 College Street, Suite 140, Toronto, Ontario M5S 3E4, Canada.
authors.forename: Warren C W
authors.initials: WC
authors.lastname: Chan
mesh_terms: D004247:DNA / Q000737:chemistry*; D003850:Deoxyribonuclease I / Q000378:metabolism; D004738:Engineering; D006046:Gold / Q000737:chemistry; D053768:Metal Nanoparticles / Q000737:chemistry*; D049329:Nanostructures; D009841:Oligonucleotides / Q000737:chemistry; D011073:Polyamines / Q000737:chemistry*; D011108:Polymers / Q000737:chemistry*; D014357:Trypsin / Q000378:metabolism
chemical_list: D009841:Oligonucleotides; D011073:Polyamines; D011108:Polymers; D006046:Gold; D004247:DNA; D003850:Deoxyribonuclease I; D014357:Trypsin