Abstract. This study was designed to investigate the performance of carbon nanotubes (CNT) modified carbon paste and carbon printed electrodes (SPE) produced in laboratory conditions. The effect of carbon nanotube use on signal enrichment was determined by using cyclic voltammetry (CV), square wave voltammetry (SWV) or differential pulse voltammetry (DPV) techniques based on potassium ferricyanide/ ferrocyanide or guanine signal. The application of different activation procedures to the electrode surface such as chemical (H2SO4, acetone, N,N-Dimethylformamide or NaOH) or electrochemical (different potential applications) were presented in this study. It was observed that the activation procedure applied to the nanotube modified electrode has strong effects on signal enrichment. From these procedures it was determined that the guanine signal obtained in activation with NaOH increased about 62-fold. It was also found that different nanotube species gave different responses to the activation processes. The optimum conditions of the nanotube-based biosensor were also presented.
Keywords: Electrochemical techniques, DNA, biosensor, carbon nanotubes, screen printed electrode(SPE), Nucleic Acid Hybridization.