Computational Electrochemistry of DNA and its Structural Units: Effect of Lithium

Through first-principles computational methods, the general electrochemistry of deoxyribose nucleic acid (DNA) was explored in connection to redox potential. The overarching objective was to uncover the redox capabilities of novel materials for potential electrochemical applications. Thus, in a systematic approach for its analysis, DNA was divided into three structural units of interest: the nitrogenous base, the deoxyribose sugar, and the phosphate group. By analyzing nucleobases, nucleosides, and nucleotides as separate species, the contributing electrochemical effects from each of these units were elucidated. Redox potentials were calculated from an alternative thermodynamic cycle, via density functional theory (DFT) modeling with PBE0/6-31G**+. Furthermore, given that solvents are often involved in electrochemical applications, it was necessary to consider the extent of their interactions with DNA, through PBF calculations. Results were compared among cases – with solvation applied at every level of optimization and calculation, and with solvation only applied via electrostatic potential fitting. From this study, new insights are offered on the relationship between structures and properties in DNA, promoting a fuller understanding of its electrochemistry for material design.