Manipulation of Conductivity in DNA
M. Tinkham and H. Park

a) Topographic image of a DNA strand; b) Phase shift image indicating that the conductivity has increased by several orders of magnitude compared to pure l-DNA.
In previous work using a novel contactless scanning conductance method, we imaged the conductivity of l-DNA strands and found that they are insulating, apparently ruling out their use in “wiring” nano-circuits. Recently, we have discovered that by substituting Zn²⁺ ions into the base pairs of l-DNA the conductivity of the DNA strand increased sufficiently to appear on our scanning conductance probe. Further work will be needed to explore possible applications of such DNA with enhanced conductivity.