Electrochemical oxidation of ds-DNA on polypyrrole nanofiber modified pencil graphite electrode

Oezcan A., ŞAHİN Y., Oezsoez M., Turan S.

ELECTROANALYSIS, vol.19, no.21, pp.2208-2216, 2007 (SCI-Expanded) identifier identifier

  • Publication Type: Article / Article
  • Volume: 19 Issue: 21
  • Publication Date: 2007
  • Doi Number: 10.1002/elan.200703957
  • Journal Name: ELECTROANALYSIS
  • Journal Indexes: Science Citation Index Expanded (SCI-EXPANDED), Scopus
  • Page Numbers: pp.2208-2216
  • Yıldız Technical University Affiliated: No

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. PPvNF/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 mu g 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.