DNA-templated assembly of conducting gold nanowires

The use of DNA to template the assembly of gold nanowires from gold nanoparticles is reported. Double-stranded calf thymus DNA, was deposited on a polystyrene-coated silicon wafer substrate. The substrate was then exposed to an aqueous dispersion of positively charged gold nanoparticles (∼ 4 nm diameter), which adsorbed at the negatively charged DNA template. The adsorbed nanoparticles were then enlarged and enjoined by electroless deposition leading to formation of continuous nanowires of 85 nm average diameter. Gold electrodes were then overlaid on individual nanowires using conventional lithographic techniques. Two-terminal current-voltage measurements were employed to characterize the electrical characteristics of single nanowires. The nanowires exhibit resistivity values < 6 × 10^-7 Ωm. These and related findings have implications for the design and assembly of next generation electronic devices.