Development of a disposable ethanol biosensor based on a chemically modified screen-printed electrode coated with alcohol oxidase for the analysis ofbeer

A disposable amperometric biosensor for the measurement of ethanol has been developed. It comprises a screen-printed carbon electrode doped with 5% co balt phthalocyanine (CoPC-SPCE), and coated with alcohol oxidase; a permsel ective membrane on the surface acts as a barrier to interferents. The measu rement of ethanol is based on the signal produced by H2O2, the product of t he enzymatic reaction. Optimisation studies were performed using amperometr y in stirred solution and the magnitude of the signal was found to be depen dent on pH, enzyme loading, type of membrane and applied potential. The sam e technique was used to evaluate the biosensor for the determination of eth anol in samples. The results obtained compared well with the manufacturers specifications. In order to test the possibility of using the devices in th e held, chronoamperometry was also used to determine ethanol in the same be er samples. The precision and recovery data again indicated that the biosen sor should give reliable results under the conditions described. (C) 2000 E lsevier Science S.A. All rights reserved.