title: Ag K-edge EXAFS analysis of DNA-templated fluorescent silver nanoclusters: insight into the structural origins of emission tuning by DNA sequence variations.
abstract: DNA-templated silver nanoclusters are promising biological fluorescence probes due to their useful fluorescence properties, including tunability of emission wavelength through DNA template sequence variations. Ag K-edge EXAFS analysis of DNA-templated silver nanoclusters has been used to obtain insight into silver nanocluster bonding, size, and structural correlations to fluorescence. The results indicate the presence of small silver nanoclusters (<30 silver atoms) containing Ag-Ag bonds and Ag-N/O ligations to DNA. The DNA sequence used leads to differences in silver-DNA ligation as well as silver nanocluster size. The results support a model in which cooperative effects of both Ag-DNA ligation and variations in cluster size lead to the tuning of the fluorescence emission of DNA-templated silver nanoclusters.
authors.affiliation: Center for Integrated Nanotechnologies, Materials Physics and Applications Division, Los Alamos National Laboratory, Los Alamos, New Mexico 87545, USA. neidig@chem.rochester.edu
authors.forename: Michael L
authors.initials: ML
authors.lastname: Neidig
authors.forename: Jaswinder
authors.initials: J
authors.lastname: Sharma
authors.forename: Hsin-Chih
authors.initials: HC
authors.lastname: Yeh
authors.forename: Jennifer S
authors.initials: JS
authors.lastname: Martinez
authors.forename: Steven D
authors.initials: SD
authors.lastname: Conradson
authors.forename: Andrew P
authors.initials: AP
authors.lastname: Shreve
mesh_terms: D001483:Base Sequence; D004247:DNA / Q000737:chemistry*; D005453:Fluorescence; D053768:Metal Nanoparticles / Q000737:chemistry*; D015394:Molecular Structure; D012834:Silver / Q000737:chemistry*; D056928:X-Ray Absorption Spectroscopy
chemical_list: D012834:Silver; D004247:DNA