Determination of hydrogen peroxide using amperometric sensor of polyaniline doped with ferrocenesulfonic acid.

The result of cyclic voltammetry shows that polyaniline doped with ferrocenesulfonic acid (PAnFc) can effectively catalyze the oxidation of hydrogen peroxide, so PAnFc is used as a sensor to determine the concentration of H2O2. Iron in the ferrocenesulfonic acid exists in two oxidation states: Fe2+ and Fe3+. They can reversibly oxidize and reduce between the Fe2+ and Fe3+ oxidation states, which play an important role in the catalytic oxidation of H2O2. The response current of the sensor depends on the pH, applied potential and temperature at a given concentration of H2O2. At optimum conditions, the sensor has a fast response to H2O2, good operational stability, a good linear response to H2O2 in the range from 4 to 64 microM, and a small temperature dependence of the response current.