Immobilization of alcohol dehydrogenase on films prepared by the electrochemical copolymerization of pyrrole and 1‐(2‐carboxyethyl)pyrrole for ethanol sensing

Abstract

AbstractThe electrochemical copolymerization of pyrrole and 1‐(2‐carboxyethyl)pyrrole (Py‐COOH) was carried out, and a conducting polymer film with a Py‐COOH content of 5% and a conductivity of 6.6 × 10−4 S/cm was obtained. Alcohol dehydrogenase (ADH) was attached through amide linkage onto the surface of the conducting polymer film for the purpose of fabricating an ADH‐immobilized electrode applicable to the amperometric sensing of ethanol. The quantity and activity of the immobilized ADH were determined to be 400 μg/cm2 and 0.6 U/mg, respectively. With the ADH‐immobilized electrode, amperometric ethanol sensing was attempted in the presence of nicotinamide adenine dinucleotide (a cofactor of ADH) and Meldola's blue (an electron‐transferring mediator). The ADH‐immobilized electrode made the current response correspond to ethanol concentration, which reached 10 μA/cm2 at a concentration of 14 mM. The selectivity of the sensing was examined with alcohols other than ethanol. It was found that the ADH/copolymer electrode had a considerably larger current response to allyl alcohol. The selectivity was attributed to the specificity of native ADH with respect to the oxidation of alcohols. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2010