DNA-Assembled Nanoparticle Rings Exhibit Electric and Magnetic Resonances at Visible Frequencies

Abstract

Metallic nanostructures can be used to manipulate light on the subwavelength scale to create tailored optical material properties. Next to electric responses, artificial optical magnetism is of particular interest but difficult to achieve at visible wavelengths. DNA-self-assembly has proved to serve as a viable method to template plasmonic materials with nanometer precision and to produce large quantities of metallic objects with high yields. We present here the fabrication of self-assembled ring-shaped plasmonic metamolecules that are composed of four to eight single metal nanoparticles with full stoichiometric and geometric control. Scattering spectra of single rings as well as absorption spectra of solutions containing the metamolecules are used to examine the unique plasmonic features, which are compared to computational simulations. We demonstrate that the electric and magnetic plasmon resonance modes strongly correlate with the exact shape of the structures. In particular, our computations reveal the magnetic plasmons only for particle rings of broken symmetries, which is consistent with our experimental data. We stress the feasibility of DNA self-assembly as a method to create bulk plasmonic materials and metamolecules that may be applied as building blocks in plasmonic devices.

Template‐Directed Solidification of Eutectic Optical Materials

“…[64] The topography of the patterned substrate provided a sufficient bias to control the long-range order of the block copolymer. [70][71][72][73] When the DNA assembly is precisely controlled by using a patterned surface, DNA origami can be a powerful tool, for example, by dictating the arrangement of sub 10 nm components (gold nanoparticles) over large scale areas ( Figure 2C). [63][64][65][66] Template-directed assembly of molecules, DNA, and nanoparticles can also give rise to micro and nanoscale structures with promising optical responses.…”

Toward Virus-Like Surface Plasmon Strain Sensors

“…Roller et al recently reported on spectral changes occurring in 2D particle clusters supported by a DNA framework due to drying, with the main dipole resonance shift being the result of shrinkage of the cluster during drying. 6 Using AuNPs mono-conjugated to three-dimensional DNA “rung” structures, both discrete and extended linear assemblies were controllably prepared via addition of various templating backbone strands. 7 While exquisite structural control was demonstrated, the relationship between deformation and spectral properties was not pursued.…”

Characterization of Emergence of the Coulomb Blockade in a Pearl-Like DNA-AuNP Assembly

“…Also direct metallization of origami to form nanoscale wires and other metallic shapes has been investigated widely [20], but this approach does not provide an easy way to produce functional electronic devices. Many groups have demonstrated optical devices based on organizing metallic NPs exhibiting localized surface plasmon resonance [21][22][23][24], but despite the promises only few DNA based electrical devices or studies have been realized [19,[25][26][27].…”