title: Maximizing DNA loading on a range of gold nanoparticle sizes.
abstract: We have investigated the variables that influence DNA coverage on gold nanoparticles. The effects of salt concentration, spacer composition, nanoparticle size, and degree of sonication have been evaluated. Maximum loading was obtained by salt aging the nanoparticles to approximately 0.7 M NaCl in the presence of DNA containing a poly(ethylene glycol) spacer. In addition, DNA loading was substantially increased by sonicating the nanoparticles during the surface loading process. Last, nanoparticles up to 250 nm in diameter were found have approximately 2 orders of magnitude higher DNA loading than smaller (13-30 nm) nanoparticles, a consequence of their larger surface area. Stable large particles are attractive for a variety of biodiagnostic assays.
authors.affiliation: Department of Chemistry and International Institute for Nanotechnology, Northwestern University, 2145 Sheridan Road, Evanston, Illinois 60208-3113, USA.
authors.forename: Sarah J
authors.initials: SJ
authors.lastname: Hurst
authors.forename: Abigail K R
authors.initials: AK
authors.lastname: Lytton-Jean
authors.forename: Chad A
authors.initials: CA
authors.lastname: Mirkin
mesh_terms: D004247:DNA / Q000737:chemistry* / Q000378:metabolism; D006046:Gold / Q000737:chemistry*; D025202:Molecular Diagnostic Techniques; D049329:Nanostructures / Q000737:chemistry*; D010316:Particle Size; D011092:Polyethylene Glycols / Q000737:chemistry*; D012965:Sodium Chloride / Q000737:chemistry; D013499:Surface Properties
chemical_list: D011092:Polyethylene Glycols; D012965:Sodium Chloride; D006046:Gold; D004247:DNA