ELECTROCHEMICAL STUDIES OF DNA DOPED POLYPYRROLE FILMS

Abstract

Conducting polymer polypyrrole (PPy) has been a promising candidate as electrode material in various energy applications such as energy conversion and storage. The polypyrrole doped with DNA has been shown to enhance the electrochemical performance of electrode. In this work, in order to scrutinize the electrochemical performance of PPy doped with DNA, a series of polypyrrole (PPy) films doped with different other dopants coated on ITO electrodes were prepared electrochemically and studied in detail as well. Electroactivity stability of polymer film with different dopants was then investigated using cyclic voltammetry (CV) technique. The nature of counter-ion or dopant, and the concentration of dopant, was shown to affect the morphology and electroactivity of PPy films. The PPy films doped with different dopants were also characterized by scanning electron microscope (SEM) and fourier transform infrared spectroscopy (FTIR) and electrochemical properties were explored by means of cyclic voltammetry, linear sweep voltammetry and pulse voltammetry. Specific capacitance of PPy/DNA was found to be higher than those of PPy/PTSA and PPy/ DBSA films, foreseen from the larger area under Cyclic Voltammogram. Area of the CV for the PPy/DNA film have propensity to diminish with the increasing scan rate in the positive potential range of 0 to 1.2 V, representative of a poor capacitive behavior at high scanning rates, for the reason that PPy/DNA electrodes happen to be more resistive at more positive potential.