DNA biosensor based on carbon paste electrodes modified by polymer multilayer

An electrochemical DNA biosensor was developed by DNA immobilization at the electrode surface and its electrochemical behavior was studied in relation with different materials added in the paste. The aim was to study new materials for the development of new electrode surfaces, to be applied in the study of DNA-drug interactions. New electrochemical sensing materials using polymer multilayers were reported for the adsorption of DNA. These materials were prepared by mixing a polymer ion exchanger and graphite powder. The mixture was then used to render the modified carbon paste electrode (CPE), on the surface of which the dsDNA was adsorbed and studied by differential pulse voltammetry (DP voltammetry). The signal of guanine oxidation peak of DNA was followed. This modified biosensor was applied for the study of the interaction between DNA and the known intercalators Ethidium Bromide (EB) and Acridine Orange (AO). The established biosensor exhibited an improvement of its sensitivity and repeatability compared with the conventional CPE DNA biosensor.