RETICULATED VITREOUS CARBON-BASED COMPOSITE BIENZYME ELECTRODES FOR THE DETERMINATION OF ALCOHOLS IN BEER SAMPLES

ABSTRACT

The performance of a bienzyme amperometric composite biosensor for the determination of short-chain alcohols is reported. Alcohol oxidase and horseradish peroxidase together with the mediator ferrocene were incorporated into reticulated vitreous carbon (RVC)-epoxy resin electrode matrices. Under the optimized experimental conditions, the composite bienzyme electrode exhibited rapid amperometric responses at 0.00 V to the changes in the substrate concentration. The lifetime of each single biosensor was estimated to be ca. 20 days, and reproducible responses were obtained with different electrodes constructed in the same manner. Calibration plots were obtained for methanol, ethanol, propanol, butanol, and 1-pentanol. The detection limits were, in general, considerably better than those found in the literature with other AOD amperometric biosensors. The bienzyme composite electrode showed a good performance also in flow-injection systems with amperometric detection. The suitability of the bioelectrode for a simple, rapid, and selective determination of ethanol in a local beer, with a minimal sample preparation, is demonstrated.

Keywords:

• Short-chain alcohols
• Bienzyme composite electrodes

ACKNOWLEDGMENTS

The financial support of the Ministerio de Ciencia y Tecnología, Project BIO00-0928, is gratefully acknowledged.