Application of elimination voltammetry to the resolution of adenine and cytosine signals in oligonucleotides. I. Homooligodeoxynucleotides dA(9) and dC(9)
Elimination voltammetry with linear scan (EVLS) has been applied to the resolution of reduction signals of adenine and cytosine in short synthetic homo-oligodeoxynucleotides (dA(9), and dC(9),). In comparison with the common electrochemical methods (linear sweep, differential pulse, and square-wave voltammetry) EVLS enables one to resolve the overlapped signals by using the function which eliminates the charging and kinetic currents (I-c, I-k) and conserves the diffusion current (I-d). For the adsorbed electroactive substance, this elimination function gives a good readable peak-counterpeak which has successfully been utilized to the analysis of overlapped reduction signals of adenine and cytosine on hanging mercury drop electrode (HMDE). The height and potential of signals studied were affected by the dC(9)/dA(9) ratio, the time of accumulation, the stirring speed during the adsorption, and pH. Our results showed that EVLS in connection with the adsorption procedure is a useful tool for qualitative and quantitative studies of short oligonucleotides.