DNA-Mold Templated Assembly of Conductive Gold Nanowires

Abstract

We introduce a new concept for the solution-based fabrication of conductive gold nanowires using DNA templates. To this end, we employ DNA nanomolds, inside which electroless gold deposition is initiated by site-specific attached seeds. Using programmable interfaces, individual molds self-assemble into micrometer-long mold superstructures. During subsequent internal gold deposition, the mold walls constrain the metal growth, such that highly homogeneous nanowires with 20-30 nm diameters are obtained. Wire contacting using electron-beam lithography and electrical conductance characterization at temperatures between 4.2 K and room temperature demonstrate that metallic conducting wires were produced, although for part of the wires, the conductance is limited by boundaries between gold grains. Using different mold designs, our synthesis scheme will, in the future, allow the fabrication of complex metal structures with programmable shapes.

DNA‐Mediated Self‐Assembly and Metallization of Semiconductor Nanorods for the Fabrication of Nanoelectronic Interfaces

“…Recently, we demonstrated, however, that the decoration of molds chains with AuNPs at efficiencies of 96±2 % by using identical internal positions of capture strands . We therefore attribute the limited accessibility to the internal docking sites to the anisotropic NR geometry.…”

“…In particular, recent developments in DNA nanotechnology, such as the DNA origami technique, provided a straightforward route to fabricate 2D and 3D scaffolds that allowed for a precise arrangement of different materials through DNA‐strand hybridization. Prominent examples include the demonstration of an DNA‐templated carbon nanotube field‐effect transistor and the assembly of conductive gold nanowires . To this end, one‐dimensional semiconductor nanorods (SC NRs) are another promising material type, due to their synthetically designable anisotropic optical and electrical properties.…”

“…We next tested whether the freshly functionalized NRs can be bound on a DNA origami platform at defined positions (see scheme in Figure d). The origami structure was a so‐called DNA mold, being a tube with quadratic cross section composed of 64 helices with outer dimensions of 25×25×40 nm and a cavity of 15×15×40 nm (for details see Supporting Information Figure S8–S10) . Complementary poly‐A 15 capture strands were incorporated at specific positions on the out‐ or inside of the mold to allow binding of the functionalized NRs.…”

Create Nanoscale Patterns with DNA Origami

“…Over the last decade, growing interest has been reported in patterning DNA origami‐assembled metallic nanoparticles for the construction of complex nanoelectronics and optical devices, due to their unique optical properties such as Fano resonances, chirality, surface‐enhanced Raman, and fluorescence enhancement . The assembly of metallic nanoparticles relies on the functionalization of metal nanoparticles with thiol‐modified single‐stranded DNA as linkers.…”

Organic Templates for Inorganic Nanocrystal Growth

“…The former approach (i.e., finding a cubic capsid) may prove to be a daunting task with no guarantee of success. [279] However, the scalability of such strategy remains an issue and the materials that can be cast into DNA origami is still limited to noble metals, due to the mild seeded-growth process. Though vastly different, block copolymer templates face their own set of problems for future development.…”