Effect of ionic liquid on the long-term structural and chemical stability of basidiomycetes DNAs integrated within Schottky-like junctions

Abstract

There is much interest in the use of deoxyribonucleic acid (DNA) for applications in the field of molecular electronics and biosensors because of its unique self-assembling behaviour. Studying its sequence-specific electronic properties is one such analysis that could be employed as a tool for understanding mechanisms of charge transfer for integration into DNA-based devices. Although known to be reasonably stable in aqueous solution, environmental factors can affect the helical structure, resulting in significantly attenuated electronic profile. DNA molecules are also not stable when stored for long periods in solution form at room temperature prompting many interests for solvents in which DNA structures exhibit long-term stability. Ionic liquid (IL), 1-butyl-3-methylimidazolium acetate ([BMIM][Ace]), is a potential solvent that ensures long-term stability of DNA. Therefore, in this work, the effect of IL on basidiomycetes DNAs integrated within an aluminium (Al)–indium tin oxide (ITO) Schottky junction was investigated. Significant improvement in the rectifying profiles was observed for DNA dissolved in [BMIM][Ace] (IL/DNA) compared to DNA in aqueous solution (aq/DNA) without the addition of IL when stored at different temperatures and time intervals. In general, the junction structure exhibited insulating behaviour when DNA was stored at room temperature for three months. This results in loss of its structure and stability for long periods of use at room temperature. Meanwhile, IL sample itself (control) shows a linear conductive profile. Furthermore, different solid-state parameters calculated allow us to understand the charge transfer mechanism in DNA molecules as a function of IL.