Boron-doped diamond electrodes explored for the electroanalytical detection of 7-methylguanine and applied for its sensing within urine samples. (10th April 2016)

• Record Type: Journal Article
• Authors: Sanjuán, Ignacio; Brotons, Ariadna; Hernández-Ibáñez, Naiara; Foster, Christopher W.; Banks, Craig E.; Iniesta, Jesús
• Is Part Of: Electrochimica acta. Volume 197(2016)
• Page Start: 167
• Page End: 178
• Publication Date: 2016-04-10
• Subjects: 7-Methylguanine -- Epigenetic modification -- Urine -- Electrochemical sensor -- Boron doped diamond electrode; Electrochemistry -- Periodicals; Electrochemistry, Industrial -- Periodicals; 541.37
• DOI: 10.1016/j.electacta.2015.11.026
• Languages: English
• ISSNs: 0013-4686

Abstract

Highlights: Facile determination of N7-methylguanine (7-mG) by electrochemical methods, which may represent a tool for diagnosis, prevention and the monitoring of diseases. SWV provides good resolution of the anodic peak for 7-mG and the main nucleic bases interferences, such as adenine and guanine. It is plausible the simultaneous determination of 7-mG and another of the most common modified nucleobases, 8-oxoguanine (8-oxoG). 7-mG electrochemical determination within a human urine sample is feasible with linear regression between peak current intensity versus 7-mG concentration. Abstract: Epigenetic modifications have been associated by many studies with several types of diseases and metabolic dysfunctions. Specifically, N7-methyl modification of guanine (7-mG) is well established to be used as a biomarker for the detection and determination of DNA methylation. The use of an electrochemical sensor has the potential to provide a simpler and more economic sensing methodology for the determination of 7-mG compared to traditionally utilised laboratory based approaches. In this paper we demonstrate the feasibility of an electrochemical sensor which could potentially be easily applied towards the determination of 7-mG within biological samples, such as human urine. A practical electrochemical configuration was employed consisting of a boron-doped diamond electrode (BDD) as the working electrode and a screen-printed graphite electrode (SPE) providing the counter electrode and the reference electrode. With this new protocol, the electrochemical behaviour of 7-mG has been investigated via cyclic voltammetry (CV) and square wave voltammetry (SWV) using a BDD electrode with a simplified electrochemical set-up. The electrochemical behaviour of 7-mG within acetate buffer solutions at a BDD electrode has been compared and contrasted to a glassy carbon electrode with the following parameters studied: voltammetric scan rate, solution pH, 7-mG concentration and electrode surface pretreatment. The oxidative mechanism elucidation has been performed at controlled potential and such results have provided the dimer formation as the major product. The simultaneous electroanalytical identification of 7-mG together with the presence of guanine, adenine and 8-oxoguanine has been investigated under the optimum experimental conditions. Furthermore, the feasibility of using a BDD electrode for the detection of 7-mG is explored in a human urine sample.