Alcohol biosensor based on alcohol dehydrogenase and Meldola Blue immobilized into a carbon paste electrode.

A yeast alcohol dehydrogenase amperometric carbon paste-based biosensor, with Meldola Blue as a mediator and a dialysis membrane with a very small molecular weight cut-off for protection, is described. The influence of membrane pore size on the stability and overall kinetics of the biosensor is shown using cyclic voltammetry and stationary potential measurements. The operating potential is + 50 mV vs. Ag/AgCl, KCl sat. reference electrode. Application of this device to the determination of ethanol in alcoholic beverages was achieved successfully. In these kinds of samples and at this working potential no interferences were found.