Resumo

JUNIOR, A.R.S.  e  REBELO, M.J.F.. Biosensors for the Polyphenolic Content of Wine Determination. Port. Electrochim. Acta [online]. 2008, vol.26, n.1, pp.117-124. ISSN 0872-1904.

Laccase of different lots was used in the construction of biosensors for the determination of polyphenolic content of wine. Laccase was immobilized on modified polyethersulfone membranes and applied to a Universal Sensor electrode base system. Parameters of the biosensors thus prepared were studied with respect to caffeic acid as the model substrate. Sensitivity of 0.102 mA × M^-1, RSD of 1.9%, linear range of 5 to 35 × 10^-6 M, limit of detection of 8.8 × 10^-7M, were determined.  Different values of the applied potential near 0 V were tested in order to choose that one which gives the best performance of the present biosensors.  Citrate and tartarate buffer solutions at pH 3.5 were used. Polyphenolic content of different red wines was determined at +100 mV vs. Ag/AgCl.

Palavras-chave : polyphenolic; wine; biosensor; laccase; caffeic acid.

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