The Theoretical Description for the Use of Poly(7-hydroxyphenoxazone) as Electrode Modifier for pH Monitoring

The possibility of electroanalytical variation for a well-known litmus acidity test has been evaluated theoretically. In this system, pH is measured by a carbon material electrode, modified by the electropolymerized 7-hydroxyphenoxazone – the most pH-sensitive litmus dye. The investigation of the correspondent mathematical modeling confirms that the poly(7-hydroxyphenoxazone)-modified cathode is suitable for the pH measurements, especially in neutral and acidic solutions. Although the oscillatory and monotonic instabilities are more probable than in similar systems, the electroanalytical process tends to be efficient, and the analytical signal is easy to interpret.