Analysis of Impedance Stabilization of Natural and Metallic DNA Molecules

Abstract

In this work, we used lambda-DNA to produce metallic DNA samples and we investigated the stabilization time of their impedances. This is in order to show that the DNA molecules can possibly be utilized as a frame for assembling the nanocircuits and as an electronic element as well, in nanoelectric devices. It has been shown that metallic DNA has lower stabilization time than natural DNA. As expected, it is shown that making the bundled DNA oriented, impacts their impedance stabilization. In order to find the characteristic impedance of the DNA molecules under direct current, we designed and made patterned electrodes to make electrical connections between the DNAs and the used current source. The electrodes are made from gold with a gap distance lower than about 10 micrometer in order to let the DNA bundles to be under electric field between electrode gaps with a length of 11 micrometer. Different experiments are done on DNA strings in different environmental bias conditions. When comparing the impedance stabilization time of natural DNAs with metallic Zn-DNAs, while the conductivity of the metallic DNA is higher, we found that Zn-DNA response is faster than the natural DNA molecules. This might be interpreted to be caused by the better conductivity of the structures of the metallic samples with the consideration of the same intrinsic capacitances for both types of the DNAs.