Blend of Metal Oxides and Polyaniline on Platinum Electrodes for Dissolved Oxygen Sensors

Abstract

In this study, we report the detection of dissolve oxygen (DO) by using a blend of Ruthenium oxide and polyaniline (PANI) coated on platinum electrodes. Optical properties of the PANI were characterized by using Ultraviolet - Visible (UV-Vis) and Fourier-transform infrared (FTIR) spectroscopy. In order to study the sensitivity of the thin films of the PANI and PANI: Ruthenium oxide blend, cyclic voltammetry (CV) measurements was performed with the platinum electrodes coated with the thin films of PANI: Ruthenium oxide. The electrolyte solutions were prepared from the phosphate buffer and had the salinity of 20‰ and pH 7.3. The CV measurements were carried out when the electrodes were put in the electrolyte solutions which had various DO concentrations by purging pure nitrogen and oxygen gases. The DO concentrations in the experiments were measured by a commercial dissolved oxygen probe. The correlation between the current in the CV measurements and DO concentrations was determined. The effect of the blending ratio of the metal oxide and PANI on the electrochemical signal was also specified. The results showed that the platinum electrodes with PANI: Ruthenium oxide blend coating exhibited a high possibility as electrochemical sensor for detection of low levels of DO in aqueous phase.