Parameters guiding the self-assembly of quantum dots and DNA origami by peptide-PNA

Nanoparticle (NP)-binding peptides conjugated to peptide nucleic acids - peptide-PNA - enable efficient and programmable self-assembly of quantum dots (QDs) on DNA nanostructures. As an alternative to chemically modified DNA, peptide-PNA were designed with a poly-histidine peptide motif (Histag) to enable self-assembly to the surface of ZnS-shelled QDs, along with a PNA domain which could undergo hybridization to a complementary DNA sequence by Watson-Crick base pairing. We have demonstrated that QDs can be conjugated efficiently to DNA origami by peptide-PNA without requiring a large excess of the individual components. Here, optimization was performed to assess the effects of varied molar ratios of peptide-PNA:QDs and QDs:origami on the binding efficiency of QDs to DNA origami.