Silver Nanoassemblies Constructed from Boranephosphonate DNA

Spatially selective deposition of metal onto complex DNA assemblies is a promising approach for the preparation of metallic nanostructures with features that are smaller than what can be produced by top-down lithographic techniques. We have recently reported the ability of 2'-deoxyoligonucleotides containing boranephosphonate linkages (bpDNA) to reduce AuCl4-, Ag+, and PtCl42- ions to the corresponding nanoparticles. Here we demonstrate incorporation of bpDNA oligomers into a two-dimensional DNA array comprised of tiles containing double crossover junctions. We further demonstrate the site-specific deposition of metallic silver onto this DNA structure which generates well-defined and preprogrammed arrays of silver nanoparticles. With this approach the size of the metallic features that can be produced is limited only by the underlying DNA template. These advances were enabled due to a new method for synthesizing bpDNA that uses a silyl protecting group on the DNA nucleobases during the solid-phase 2'-deoxyoligonucleotide synthesis.