title: RNA-mediated control of metal nanoparticle shape.
abstract: RNA sequences previously isolated by in vitro selection were further characterized for their ability to control palladium particle growth. Five pyridyl-modified RNA sequences (Pdases) representing each of the different evolved families were found to form hexagonal plates with a high degree of shape specificity. However, a sixth nonrelated pyridyl-modified RNA sequence was found to form exclusively cubic particles under identical conditions. Replacing pyridyl-modified RNA with native RNA resulted in a complete loss of RNA function. Removing the 3'-fixed sequence region from the Pdase had little effect on particle growth; however, further truncations into the variable region resulted in a significant loss of activity and particle shape control. These Pdases were selected using the organometallic precursor complex tris(dibenzylideneacetone) dipalladium(0) ([Pd2(DBA)3]). Changing the metal center and ligand of the group VIII organometallic precursor complex revealed a strong dependence of particle growth and shape on the DBA ligands. Changing the metal center from Pd to Pt while retaining the DBA ligands gave predominantly hexagonal Pt, but with a decrease in shape control. Taken together, the results of this study suggest that the full-length Pdases contain active sites capable of highly specific molecular recognition of organometallic complexes as particle formation reagents.
authors.affiliation: W. M. Keck Center for RNA-Mediated Materials Synthesis, Department of Chemistry, North Carolina State University, Raleigh, North Carolina 27695, USA.
authors.forename: Lina A
authors.initials: LA
authors.lastname: Gugliotti
authors.forename: Daniel L
authors.initials: DL
authors.lastname: Feldheim
authors.forename: Bruce E
authors.initials: BE
authors.lastname: Eaton
mesh_terms: D001483:Base Sequence; D004277:DNA, Single-Stranded / Q000737:chemistry; D008024:Ligands; D008969:Molecular Sequence Data; D049329:Nanostructures / Q000737:chemistry*; D010165:Palladium / Q000737:chemistry*; D010984:Platinum / Q000737:chemistry*; D012313:RNA / Q000737:chemistry*
chemical_list: D004277:DNA, Single-Stranded; D008024:Ligands; D010984:Platinum; D010165:Palladium; D012313:RNA