Characterization of graphite-epoxy composite electrodes for free electrochemical detection of adenine and guanine in DNA

Graphite-epoxy composites (GECs) are alternative construction materials for electro­chemical sensors. For these materials, the electron transfer rate constant of some redox reaction depends additionally on stoichiometric relationship between insulating and conducting phases composite. In this work, influence dif­fe­rent ratios araldite/hardener/graphite electrochemical properties GEC electrodes is evaluated simultaneous determination adenine guanine in single chain DNA, using square wave voltammetry technique. Six electro­des were prepared with different components, electrochemically charac­terized by cyclic presence ferri/ferrocyanide couple as a probe. that showed best responses probe characterized thermogravimetric analysis (TGA) used simul­taneous free solution, DNA oligonu­cle­otides. The results obtained containing twice higher volu­me araldite resin respect to hardener. TGA revealed 15-26 % electrodes. potential appl­ication sensors based oxidation signal guanine.