DNA Origami Templated Gold Nanoparticles Assembly With Their Fano Resonance Effect

Because of high electron density,surface plasmon resonance and biocompatibility,metal nanoparticles show great potential in application of catalysis,electrons,sense and biomedical aspects.Using bottom-up approaches to assemble noble metal nanoparticles is a hot pot in the field of nanotechnology.DNA origami is created by folding a long single-stranded virus DNA with hundreds of short DN A staples into arbitrary shapes in multiple dimensions.In DNA origami structures,each of the staples has unique position which means DNA origami nanostructures are addressable in nanoscale.This property makes DNA origami a good template for positioning and assembly of metal nanoparticles.Also,DNA nanotechnology provides various ways to contro l the positioning of nanoparticles,to regulate their interactions and to effectively contro l the self-assembly of nanoparticles.Here we employed two DNA origami nanostructures as templates to site-specifically anchoring gold nanorods and nanocubes.Thus prepared metal nanostructures had unique fano resonance because of the interaction of individual gold nanoparticles.Based on the above content,the research content of this thesis is divided into three aspects.1.Gold nanorod(AuN Rs)and gold nanocube(AuNCs)with uniform morphology and size are prepared by seed-induced growth methods.Different diameter ration of Au NRs and Au NCs were obtained by adjusting the mount of seeds.Silver nitrate was added in to order to achieve the required size.The preparation of metal nanoparticles provides sufficient raw materials for subsequent experiments.2.Au NRs were firstly assembled by thiol DNA strands in a medium density.Rectangular DNA origami was employed as template for the site-specifically anchoring of three individual Au N Rs into the dolmen-shape nanostructures.Transmission electron microscopy(TEM)images showed the formation of dolmen-shape nanostructures in high yields.The scattering spectrum with fano resonance were observe by the colocalization of dark-field microscopy and scanning electron microscopy.3.Au NCs and Au NRs were used to form dimers on the template of a triangular DNA origami.Transmission electron microscopy(TEM)images showed the formation of the diner nanostructures in high yields.Their scattering spectrum with fano resonance were observe by the colocalization of dark-field microscopy and scanning electron microscopy.