Resolution of overlapped reduction signals in short hetero-oligonucleotides by elimination voltammetry
| Authors | |
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| Year of publication | 2006 |
| Type | Article in Proceedings |
| Conference | 11th International conference on electroanalysis |
| MU Faculty or unit | |
| Citation | |
| Field | Electrochemistry |
| Keywords | Electrochemistry; Hetero-oligonucleotides; Mercury electrode; Elimination voltammetry with linear scan; |
| Description | Introduction. Recently, the elimination voltammetry with linear scan (EVLS) was successfully applied to data analysis of oligodeoxynucleotides (ODNs) signal, aiming on better understanding of basic electrochemical processes on working electrode surfaces, and for better resolution of voltammetric signals of adenine and cytosine in ODNs. The EVLS provides a significant increase of voltammetric signal sensitivity. Materials and methods. Linear sweep voltammetry (LSV) measurements were performed with an AUTOLAB analyzer (EcoChemie, Netherlands) connected to the VA-Stand 663 (Metrohm). The electrochemical standard cell consisted of three electrodes. The working electrode was a hanging mercury drop electrode; the reference electrode was Ag/AgCl/3M KCl. Platinum wire was used as an auxiliary electrode. The adsorption of ODNs was carried out at 0.1 V for accumulation time of 120 s under stirring. For the elimination procedure three different scan rates were used. Results. We applied elimination voltammetry with linear scan to the resolution of reduction signals of adenine and cytosine residues in short synthetic hetero-oligodeoxynucleotides with different sequences of adenine and cytosine. The EVLS is capable of resolving the overlapped adenine and cytosine signals, specifically by using the elimination function which eliminates the charging and kinetic currents and conserves the diffusion current. This function provides the special peak-counterpeak signal which increases the current sensitivity for adenine and cytosine resolution. It was found that heights and potentials of voltammetric signals were affected by ODNs concentrations, pH, scan rates, time of accumulation, and stirring speed during the adsorption. While on linear sweep curves the only reduction peak of adenine and cytosine residues was observed in all ODNs, the EVLS yielded two separated peaks in dependence on adenine and cytosine sequences and pH. Conclusions. The EVLS offers a new tool for very good resolution of these bases in ODNs, and for a qualitative and quantitative sensing device for changes in the primary structure of ODN chains. It can be expected that in case of identical number of reducible bases the technique will even make it possible to distinguish between neighbouring and non-neighbouring bases. |
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