Investigation on Tungsten Needle pH Sensor Modified by Polyaniline Film and its Applications to the Crucian pH Detection

Abstract

Abstract A tungsten electrode modified with polyaniline was prepared as working electrode, the platinum wire electrode for counter electrode, and the saturated Ag/AgCl redox system for reference electrode, with the base on solution H2SO4 (1.5mol/L) vs. aniline solution 0.1mol/L. The sensor showed a Nernst response in the pH range of 2~12 and a response time less than 1 min. Connected the tungsten filament electrode and silver wire electrode (mentioned above) to the anode and cathode of the pHS-25 type pH meter respectively, inserted the electrodes to the measured positions of the sample, and then recorded the potential reading when the potential value was stable, the results would be quantified by the curve (E-pH curve) finally.The sensor has been successfully employed to determine pH in the crucian from the live fish to the putrefied fish.