SQUARE WAVE VOLTAMMETRIC METHOD FOR ERLOTINIB DETERMINATION AT DNA MODIFIED GLASSY CARBON ELECTRODE

Abstract

Erlotinib (ERL) is tyrosine kinase inhibitor which interacts with DNA double helix. It is electroactive compound capable of being irreversibly oxidized at glassy carbon electrode (GCE) in the pH range from 2 to 9. The intensity of the square wave voltammetric oxidation peak of ERL decreased with the increase of pH, while its peak potential is shifted towards less positive values. The best condition to follow the interaction between ERL and DNA is at pH 4.6 where both compounds are stable and SWV peaks are well pronounced. The aim of this work was to utilize the interaction of ERL with DNA in order to determine the minimum amount of ERL that is capable to react with DNA. For that purpose GCE modified with adsorbed layer of DNA on its surface was used. On the basis of the achieved linear dependence of peak current intensity on ERL concentration in the solution ranged 3.0´10-7 M ‒ 2.0´10-6 M, the lowest detectable content of ERL able to interact with DNA was obtained as LOD=1.45´10-7 M.