DNA-Templated Assembly of Conducting Gold Nanowires between Gold Electrodes on a Silicon Oxide Substrate

Here we report on the DNA-templated self-assembly of conducting gold nanowires between gold electrodes lithographically patterned on a silicon oxide substrate. An aqueous dispersion of 4-(dimethylamino)pyridine-stabilized gold nanoparticles was prepared. These nanoparticles recognize and bind selectively double-stranded calf thymus DNA aligned between the gold electrodes to form a linear nanoparticle array. Continuous polycrystalline gold nanowires are obtained by electroless deposition that enlarges and enjoins the individual gold nanoparticles. The above nanowires were structurally characterized using a range of electron and scanning probe microscopies and electrically characterized at room temperature using a standard probe setup. The results of these characterizations show these wires to be 20 nm high and 40 nm wide, to be continuous between interdigitated gold electrodes with an interelectrode spacing of 0.2 or 1.0 μm, and to possess a resistivity of 2 × 10 - 4 Ωm. These DNA-templated nanowires, the smallest reported to date, exhibit resistivities consistent with reported findings and current theory. The use of DNA as a template for the self-assembly of conducting gold nanowires represents a potentially important approach to the fabrication of nanoscale interconnects.