Controlling the Molecular Structure and Electrical Conductivity of DNA via Photoswitch Molecules

Abstract

The ever-increasing size of digital data requires novel storage techniques and materials that provide data storage densities surpassing today’s semiconductors. It is also important to write, read and store at a low cost and in an energy efficient manner. Biomolecules such as DNA and RNA, which are the fundamental building blocks for genetic information, are considered as a solution to this problem. Over the last two decades, it has been shown that the electrical conduction of DNA can be controlled by sequence, environmental factors and doping with different molecules. Uncovering the mechanisms of these effects is important to create DNA based circuits with desired properties. It is also known that light-sensitive molecules such as azobenzene, butadiene and stilbene change their structure (cis/trans) when excited by light of different wavelengths, and such molecules are called photoswitch molecules. Here, we investigated whether the conductivity of DNA can be controlled with the help of photoswitch molecules using atomistic and quantum mechanical methods. In this presentation, we first discuss the results of the molecular dynamic trajectories and the effect of the attached photoswitch molecules on the selected DNA sequences. Then we used clustering algorithms to find the most representative molecular conformation for further analysis. Finally, the electrical conductivities of the bare DNA and the azobenzene (cis and trans) attached DNA were calculated using DFT and Green Function based transport calculations. We demonstrated that, the photoswitch molecules can be used to tune the conductivity of DNA.