title: Effect of protonation on the electronic properties of DNA base pairs: applications for molecular electronics.
abstract: Protonation of DNA basepairs is a reversible phenomenon that can be controlled by tuning the pH of the system. Under mild acidic conditions, the hydrogen-bonding pattern of the DNA basepairs undergoes a change. We study the effect of protonation on the electronic properties of the DNA basepairs to probe for possible molecular electronics applications. We find that, under mild acidic pH conditions, the A:T basepair shows excellent rectification behavior that is, however, absent in the G:C basepair. The mechanism of rectification has been discussed using a simple chemical potential model. We also consider the noncanonical A:A basepair and find that it can be used as efficient pH dependent molecular switch. The switching action in the A:A basepair is explained in the light of pi-pi interactions, which lead to efficient delocalization over the entire basepair.
authors: Theoretical Sciences Unit, Jawaharlal Nehru Center for Advanced Scientific Research, Jakkur Campus, Bangalore, India.
authors: Sairam S
authors: SS
authors: Mallajosyula
authors: Swapan K
authors: SK
authors: Pati
mesh_terms: D020029:Base Pairing; D004247:DNA / Q000737:chemistry*; D004581:Electronics; D006860:Hydrogen Bonding; D008956:Models, Chemical; D011522:Protons; D055672:Static Electricity
chemical_list: D011522:Protons; D004247:DNA