title: Ultrasensitive DNA detection using oligonucleotide-silver nanoparticle conjugates.
abstract: Oligonucleotide-gold nanoparticle (OGN) conjugates are powerful tools for the detection of target DNA sequences due to the unique properties conferred upon the oligonucleotide by the nanoparticle. Practically all the research and applications of these conjugates have used gold nanoparticles to the exclusion of other noble metal nanoparticles. Here we report the synthesis of oligonucleotide-silver nanoparticle (OSN) conjugates and demonstrate their use in a sandwich assay format. The OSN conjugates have practically identical properties to their gold analogues and due to their vastly greater extinction coefficient both visual and absorption analyses can occur at much lower concentrations. This is the first report of OSN conjugates being successfully used for target DNA detection and offers improved sensitivity which is of interest to a range of scientists.
authors.affiliation: Centre for Molecular Nanometrology, WestCHEM, Department of Pure and Applied Chemistry, University of Strathclyde, 295 Cathedral Street, Glasgow, G1 1XL, UK.
authors.forename: David G
authors.initials: DG
authors.lastname: Thompson
authors.forename: Alexis
authors.initials: A
authors.lastname: Enright
authors.forename: Karen
authors.initials: K
authors.lastname: Faulds
authors.forename: W Ewen
authors.initials: WE
authors.lastname: Smith
authors.forename: Duncan
authors.initials: D
authors.lastname: Graham
mesh_terms: D020137:Base Pair Mismatch; D004247:DNA / Q000032:analysis* / Q000737:chemistry / Q000235:genetics; D053768:Metal Nanoparticles / Q000737:chemistry*; D008855:Microscopy, Electron, Scanning; D009841:Oligonucleotides / Q000138:chemical synthesis / Q000737:chemistry*; D012680:Sensitivity and Specificity; D012834:Silver / Q000737:chemistry*; D013056:Spectrophotometry, Ultraviolet / Q000379:methods; D013438:Sulfhydryl Compounds / Q000737:chemistry; D013696:Temperature
chemical_list: D009841:Oligonucleotides; D013438:Sulfhydryl Compounds; D012834:Silver; D004247:DNA