Directed assembly of DNA-functionalized gold nanoparticles using pyrrole–imidazole polyamides

Traditional methods for the construction of nanoparticle arrays and lattices exploit Watson–Crick base pairing of single-stranded DNA sequences as a proxy for self-assembly. Although this approach has been utilized in a variety of applications in nanoassembly, diagnostics, and biomedicine, the diversity of this recognition lexicon could be considerably increased by developing strategies that recognize the base-pairing landscape of double-stranded DNA (dsDNA) sequences. Herein we describe the first report of programmed gold nanoparticle (GNP) aggregation directed by the recognition of dsDNA sequences using pyrrole–imidazole polyamide–GNP (PA–GNP) conjugates. We demonstrate the reversibility and selectivity of this strategy for forming GNP aggregates in the presence of fully matched dsDNA sequences relative to dsDNA sequences containing one- and two-base-pair mismatches