Electrochemical Oxidation of ds‐DNA on Polypyrrole Nanofiber Modified Pencil Graphite Electrode
Makaleler > Tam Makale · 2007
Yazarlar: Ali Özcan, Yücel Şahin, Mehmet Özsöz, Servet Turan
Electroanalysis, Uluslararası, Wos, 2007, cilt 19, ss 2208-2216
Özet
Abstract Preparation of a polypyrrole nanofiber (PPyNF) modified pencil graphite (PG) electrode and its usage in the electrochemical DNA biosensors was investigated. The electrodes (PPyNF/PG1 and PPyNF/PG2) were prepared from a solution containing 0.1 M pyrrole, 0.1 M Na2CO3 and 0.1 M LiCIO4 by using potentiostatic and potentiodynamic methods. PPyNF/PG2 electrodes which were prepared by potentiostatic procedure showed higher responses for the oxidation of ds‐DNA than the PPyNF/PG1 electrodes prepared by potentiodynamic methods. Immobilization of the ds‐DNA on PG and PPyNF/PG surfaces was performed at a constant potential, +0.5 V, for 300 s in 0.5 M ABS (pH 4.8) containing 15 μg mL−1 ds‐DNA and 20 mM LiCIO4. The oxidation peak potentials of the ds‐DNA bases, guanine and adenine, were shifted to more cathodic values by using PPyNF/PG electrodes. The oxidation signal of the guanine base of ds‐DNA was decreased in the presence of methylene blue.