Ethanol bioelectrooxidation in a robust poly(methylene green-pyrrole)-mediated enzymatic biofuel cell

We prepared robust bioanodes by immobilizing the alcohol dehydrogenase (ADH) enzyme onto a one-pot electropolymerized film consisting of methylene green and pyrrole. The enzymatic film containing immobilized ADH furnished power densities as high as 183 +/- 10 mu W cm(-2); addition of carbon nanotubes (MWCNTs) increased the bioanode power density to 275 +/- 12 mu W cm(-2). The bioanode was very stable, with a mean decay of 36% of its initial power density after 20 weeks of storage. Long-term ethanol electrolysis (12h) followed by HPLC-UV/RID confirmed that the system was highly selective and generated a two-electron product. MWNCT introduction provided five times higher acetaldehyde production. Compared to literature data, results were promising and showed that the system can be used to construct biofuel cells. In addition, the film obtained by simultaneous methylene green and pyrrole electropolymerization afforded interesting results and can be applied in other systems, such as biosensors.