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

Autor: Abel Ibrahim Balbin Tamayo, Leodanis Correa Fajardo, Ana Margarita Esteva Guas
Jazyk: angličtina
Rok vydání: 2021
Předmět:
Zdroj: Journal of Electrochemical Science and Engineering, Vol 11, Iss 3 (2021)
Druh dokumentu: article
ISSN: 1847-9286
DOI: 10.5599/jese.1005
Popis: 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.
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