Single-stranded DNA encapsulates silver clusters, and we consider blue-green and near-infrared chromophores whose spectra are directed by DNA structural changes. We show how these changes are used to detect oligonucleotides. A common type of DNA template has two components: the 3' sequence hybridizes with target oligonucleotides and the 5' sequence forms specific silver clusters. These composite strands exclusively harbor an ∼10 silver atom cluster that absorbs at 400 nm with limited emission. When a target hybridizes with these single-stranded conjugates, cluster absorption shifts and strong emission develops. Fluorescence anisotropy, fluorescence correlation spectroscopy, size exclusion chromatography, elemental analysis, and temperature-dependent spectral measurements identify two structural and thermodynamic changes accompanying hybridization. First, the violet cluster folds its single-stranded host and inhibits DNA hybridization. Second, the violet cluster dimerizes its DNA host and forms a near-infrared cluster. Our key conclusion is that silver clusters are both chromophoric reporters and ligands that modulate analyte-sensor interactions.<br/>

DNA-directed synthesis of silver clusters

251st National Meeting (2016)

The official archive and repository for all ACS Meetings & Expositions abstracts and select posters or presentations.