Effects of Ionic Liquids on Nucleic Acid Secondary Structures

Abstract

The effects of ionic liquids (ILs) on DNA are not well understood. Ionic liquids are important to the chemistry of DNA because they could serve as a long-term storage buffer for DNA, contribute to the use of DNA in nanotechnology and sensors, and influence the use of DNA as a platform for designing catalysts. In this research, imidazolium chloride ionic liquids with varying alkyl chain lengths were tested for their effects on the stability and structure on a representative DNA duplex. Thermal denaturation and ionic liquid titration experiments using Circular Dichroism spectroscopy were performed to assess the stability and conformation of DNA duplexes. Results of the experiments suggested that the imidazolium ionic liquids were interacting directly with the DNA, altering its structure and causing it to precipitate out of solution by the end of our titrations. This behavior was dependent on both the alkyl chain length of the ionic liquid as well as the concentration of the DNA and suggests that precipitation of the DNA comes after ionic-liquids are saturating DNA interaction sites.