Elimination transformation of irreversible current an adsorbed electroactive substance
Authors | |
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Year of publication | 2006 |
Type | Article in Proceedings |
Conference | 57th Annual Meeting of the International Society of Electrochemistry |
MU Faculty or unit | |
Citation | |
Field | Electrochemistry |
Keywords | Electrochemistry; Hetero-oligonucleotides; Homo-oligonucleotides; Mercury electrode; Elimination voltammetry with linear scan; |
Description | Ten years ago the theory of elimination voltammetry with linear scan (EVLS) was published and experimentally verified for reversible, quasi-reversible and irreversible electrode systems [1,2]. Up to date this method has found applications not only in electroanalysis, but also in the study of electrode processes of inorganic and organic electroactive substance at mercury, silver or graphite electrodes [3-5]. The EVLS can be considered a mathematical model of the transformation of current-potential curves capable of eliminating some selected current components, and conserving others. This contribution is devoted to the EVLS transformation of irreversible current-potential curves of an adsorbed electroactive substance. The function eliminating charging and kinetic current components, and conserving the diffusion current component, yields specific, sensitive and well developed peak-couterpeak (p-cp) signal [6-7]. This signal was successfully employed in the analysis of nucleic acids and short homo- or hetero-deoxyoligonucleotides (ODNs) containing adenine (A), cytosine (C) and guanine (G). For the calculation of the elimination functions three voltammetric curves at different scan rates were recorded under identical experimental conditions. While only incompletely developed peaks or overlapped reduction peaks of A and C can be seen on LSV or CV curves, the peak-counterpeak signal is able to increase the current sensitivity and to separate two overlapped peaks. The heights and positions of p-cp signals were affected by pH, accumulation time and potential, and by the sequence of bases in ODN chains. It was shown that the EVLS in combination with adsorptive stripping procedure is a promising tool for achieving very good resolution of electrode processes in ODNs, for qualitative and quantitative analysis of ODNs, as well as for identification of neighbouring and non-neighborouring bases. |
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