Square wave voltammetric analysis of azidothymidine in the presence of oligonucleotides and chromosomal DNA
| Authors | |
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| Year of publication | 2003 |
| Type | Article in Proceedings |
| Conference | XVII th International Symposium on Bioelectrochemictry and Bioenergetics |
| MU Faculty or unit | |
| Citation | |
| Field | Electrochemistry |
| Keywords | azidothymidine; hanging mercury drop electrode; square wave voltammetry; elimination voltammetry with linear scan; oligonucleotides; chromosomal DNA |
| Description | Azidothymidine ( AZT, Zidovudine) is a synthetic nucleoside analogue with activity against human immunodeficiency virus type 1 (HIV). Recently, our working group has developed and optimised a square wave voltammetric method for analysis of AZT in biological samples. The aim of the study is the determination of AZT in the presence of synthetic oligonucleotides (ODNs) and calf thymus ssDNA or dsDNA on the hanging mercury drop electrode. Both AZT and DNA yield voltammetric signals on the mercury electrode; AZT provides an irreversible reduction peak at the potential near -1.1 V (vs. Ag/AgCl/3M KCl) and DNA provides a reduction peak of adenine and cytosine at the potential ca. -1.4 V. Square wave voltammetric signals of AZT and DNA were measured in phosphate buffer (pH 8.0) at a frequency of 2000 Hz and accumulation time of 10 s. We found that AZT peak height is not affected by the presence of DNA and therefore we assume that electron transfer proceeds through the adsorption layer of ssDNA and/or dsDNA. The detection limit of AZT is 1 nM and 250 nM in absence and in presence of ssDNA (10 mg/mL), respectively. The SWV is an effective tool for the AZT determination incorporated into oligonucleotide chains. This promising methodology ca be used to study AZT cytotoxicity and kinetics of AZT metabolism in HIV positive patients. |
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