Open AccessCharacterization of graphite-epoxy composite electrodes for free electrochemical detection of adenine and guanine in DNA
Author(s) -
Abel Ibrahim Balbin Tamayo,
Leodanis Correa Fajardo,
Ana Margarita Esteva Guas
Publication year - 2021
Publication title -
journal of electrochemical science and engineering
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.236
H-Index - 6
ISSN - 1847-9286
DOI - 10.5599/jese.1005
Subject(s) - cyclic voltammetry , redox , ferrocyanide , thermogravimetric analysis , electrode , ferricyanide , guanine , electrochemistry , epoxy , graphite , materials science , analytical chemistry (journal) , chemistry , nuclear chemistry , inorganic chemistry , composite material , organic chemistry , biochemistry , nucleotide , gene
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 the stoichiometric relationship between the insulating and conducting phases of the composite. In this work, the influence of different ratios of araldite/hardener/graphite on the electrochemical properties of GEC electrodes is evaluated for the simultaneous determination of adenine and guanine in the single chain DNA, using the square wave voltammetry technique. Six GEC electrodes were prepared with different ratios of components, and electrochemically characterized by cyclic voltammetry in the presence of ferri/ferrocyanide redox couple as a redox probe. GEC electrodes that showed the best electrochemical responses of redox probe were characterized by thermogravimetric analysis (TGA) and used for the simultaneous determination of free adenine and guanine in a solution, and DNA oligonucleotides. The best results were obtained for GEC electrodes containing twice higher volume of araldite resin with respect to the hardener. TGA analysis revealed presence of 15-26 % of resin for these GEC electrodes. The obtained results revealed potential application of these GEC electrodes as DNA sensors based on the oxidation signal of guanine.