New electrochemical approach for the measurement of oxidative DNA damage: Voltammetric determination of 8-oxoguanine at screen-printed graphite electrodes

Abstract

Simplification and miniaturisation of analytical methods for the direct detection of DNA damage is a challenging area of research and screen-printed electrodes are a promising alternative approach to analytically/electroanalytically monitor the species involved. In this work we demonstrate that screen-printed graphite macroelectrodes (SPEs) provide useful electrochemical signatures to study the behaviour of 8-oxoguanine (8-oxoGua), which is the most frequent and important marker of oxidative DNA damage and it is widely considered as a biomarker, via differential pulse voltammetry (DPV). Under the optimum experimental conditions, the proposed electrochemical sensing protocol towards 8-oxoGua using SPEs is demonstrated to be possible over the concentration range of 0.1–12μM. The response of the SPEs is superior over routinely utilised glassy carbon electrodes in terms of sensitivity with a limit of detection (3σ) found to correspond to 0.33μM. Reproducibility and repeatability of the proposed methodology at low and high concentrations were also demonstrated. Quantification of 8-oxoGua in the presence of other nucleobases and different compounds of interest which are present in biological fluids was successfully accomplished. Furthermore, proof-of-concept demonstrating the potential use of the developed SPE based methodology for the detection of 8-oxoGua in real complex samples as demonstrated in simulated biological samples (human semen).