Preparation and electrochemical behaviour of a methylene blue-modified electrode based on a Nafion polymer film

A methylene blue (MB) chemically modified electrode has been prepared by incorporating MB molecules into a Nafion polymer film on a glassy carbon surface. The electrochemical behaviour of the MB-modified polymer film electrode is discussed in detail. The electrode reaction of MB bound to the polymer film shows a reversible, two-electron transfer process with good stability and reproducibility. The equation of half-wave potential E1/2vs. pH was deduced theoretically and was proved to be reasonable experimentally by the effect of solution pH on the MB-modified polymer-film electrode. The influence of supporting electrolytes on the electrode is discussed.