Influence of the doping level on the interactions between poly(3,4-ethylenedioxythiophene) and plasmid DNA

Abstract

The influence of the doping level in the formation of specific interactions between plasmid DNA and PEDOT is investigated using experimental assays and theoretical calculations. Electrochemical methods are used to prepare polymer samples with oxidation degrees ranging from 0.14 to 1.05 positive charges per repeating unit. A combination of experimental and theoretical results are used to propose a mechanism for the formation of DNA/conducting polymer complexes, which consists of the initial stabilization of the adducts through non-specific interactions followed by small structural re-arrangements that allow to be established specific hydrogen bonds involving the polar groups of the conducting polymer and selected DNA bases.