Continued development of purification and characterization methods
Our lab has developed a tandem HPLC-mass spectrometry with inline spectroscopy method to separate single species of clusters and identify their composition and charge, including silver atom number, DNA oligomer number, and cluster charge. By investigating many such clusters, correlations between cluster size and color are apparent. DOI: 10.1039/c2cc17675k
Purification is essential for the creation of nanostructures incorporating Ag:DNAs because the cluster synthesis process produces a large number of products, both fluorescent and nonfluorescent. Selection of a population of clusters with identical properties also allows accurate determination of quantum yield and other cluster-dependent properties. Additionally, a new rod-like model has been developed for Ag-DNA cluster geometry, in part from size and charge information about single species of purified clusters. DOI: 10.1002/adma.201204624 While the initial development phase for our HPLC-MS purification method is complete, this technique continues to be an essential tool for other projects, and we continue to further improve our existing methods to increase the number of Ag-DNA species that can be purified.
