Metals, Semiconductors, and Alloy Nanowires on DNA Scaffolds: Synthesis and Device Applications

In this presentation, we will demonstrate fast and electroless UV-photo activation techniques to synthesize electrically conductive metals (Pd), semiconductors (CdS), and alloy (Au-Ag) nanowires of diameter ∼10–180 nm on DNA. The electrical characterization showed that DNA nanowires are either exhibiting Ohmic or semiconducting behavior having low contact resistance with the electrodes. The nanowires are about 1–10 micrometers long and the length depends on the molecular weight of DNA. Highly selective deposition on DNA is obtained by specific complexation between the metal ions and DNA, followed by the growth of nanoclusters in DNA chain to form the corresponding nanowires. The eventual diameter of the nanowires obtained in our experiments is over 10 nm that is significantly larger than the ∼1–2 nm diameter of the double helix DNA. The DNA nanowires orchestrated with semiconducting Si nanowires, carbon nanotubes, or co-deposited with metal nanoparticles can potentially lead to avenues for making complex single electron devices and Schottky nanodevices.