Arrangements of DNA purine bases on pyrolytic graphite electrode surface. Electrochemical characterization and atomic force microscopy imaging

Abstract

In this work we experimentally show the formation of a planarly-arranged guanine multilayer on a pyrolytic graphite surface, which was predicted by theoretical calculations at the ideal graphene surface. In the case of adenine, a multilayered architecture like that of guanine was not confirmed. Changes in the purine bases’ arrangement on charged surface in dependence on their concentration is studied using electrooxidation peaks of guanine and adenine, together with time changes in capacitance of electric double layer. Existence of predicted guanine multilayers is supported by electrochemical findings and confirmed by atomic force microscopy. Moreover, our data suggest a link between an additional guanine electrooxidation peak and supramolecular guanine assembly formation.