title: DNA capping agent control of electron transfer from silver nanoparticles.
abstract: Silver nanoparticles capped with either DNA or citrate are investigated electrochemically using stripping voltammetry and nano-impacts. Whilst the citrate capped particles are readily oxidised to silver cations at 0.7 V, the DNA capped particles undergo electron transfer from the silver core to the electrode in two distinct potential ranges -0.8 to 1.1 V and 1.125 to 1.2 V, and only undergo complete oxidation at the higher potential range. These potentials reflect the oxidation of guanine and adenine respectively, with a potential sufficient to oxidise both base pairs being necessary to observe full silver oxidation. The DNA thus serves as a tunnelling barrier to electrically insulate the particle, and allows for selective oxidation to occur by controlling the potential applied.
authors.affiliation: University of Oxford, Department of Chemistry, Physical and Theoretical Chemistry Laboratory, Oxford University, South Parks Road, Oxford, OX1 3QZ, UK. richard.compton@chem.ox.ac.uk.
authors.forename: Eden E L
authors.initials: EE
authors.lastname: Tanner
authors.forename: Stanislav V
authors.initials: SV
authors.lastname: Sokolov
authors.forename: Neil P
authors.initials: NP
authors.lastname: Young
authors.forename: Richard G
authors.initials: RG
authors.lastname: Compton
mesh_terms: D019343:Citric Acid / Q000737:chemistry; D004247:DNA / Q000737:chemistry*; D000067493:Dynamic Light Scattering; D055664:Electrochemical Techniques; D004566:Electrodes; D004579:Electron Transport; D053768:Metal Nanoparticles / Q000737:chemistry*; D046529:Microscopy, Electron, Transmission; D010084:Oxidation-Reduction; D010316:Particle Size; D012834:Silver / Q000737:chemistry*; D013053:Spectrophotometry
chemical_list: D019343:Citric Acid; D012834:Silver; D004247:DNA