Electrochemical and Surface Characterization of pH Sensor Based on Bisulfate-Doped Poly(pyrrole)

Abstract

Pyrrole was electrochemically polymerized on glassy carbon support in NaHSO4 solutions under different conditions (method applied, concentration of monomer, concentration of the main solution, thickness of the film). These variables were used to study the preparation effect on the resulting properties, in particular on the potentiometric response of the PPy-HSO4 electrodes. The electrodes were characterized by cyclic voltammetry, as well as by STM and AES techniques. Utilities of the polymer application as a sensor were studied by direct potentiometric measurements. The results obtained show that poly(pyrrole) doped with bisulfate ions can serve as pH sensor, with the slope of E/pH curves approaching the theoretical value.