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Sensors 2003, 3(6), 166-175; doi:10.3390/s30600166

A New Laccase Biosensor For Polyphenols Determination

 and *
Received: 1 April 2003 / Accepted: 5 May 2003 / Published: 29 June 2003
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Abstract: The relevance of polyphenols in human health is a well known fact. Prompted by that, a very intensive research has been directed to get a method to detect them, wich will improve the current ones. Laccase (p-diphenol:dioxygen oxidoreductase EC is a multi-copper oxidase, wich couples catalytic oxidation of phenolic substrates with four electron reduction of dioxygen to water [1]. A maximum catalytic response in oxigenated electrolyte was observed between 4.5 and 5.5 [2], while for pH > 6.9 the laccase was found to be inactive [3]. We prepared a biosensor with laccase immobilised on a polyether sulphone membrane, at pH 4.5, wich was applied at Universal Sensors base electrode. Reduction of the product of oxidation of several polyphenols, catalysed by laccase, was done at a potential for wich the polyphenol of interest was found to respond. Reduction of catechol was found to occur at a potential of -200mV, wich is often referred to in the literature for polyphenolic biosensors. However other polyphenols did not respond at that potential. It was observed that (+)- catechin produced a very large cathodic current when +100mV were applied to the laccase biosensor, both in aqueous acetate and 12% ethanol acetate buffer, whereas caffeic acid responded at -50mV. Other polyphenols tested were gallic acid, malvidin, quercetin, rutin, trans-resveratrol
Keywords: Biosensor; Laccase; Polyphenol; (+)- catechin; Caffeic acid Biosensor; Laccase; Polyphenol; (+)- catechin; Caffeic acid
This is an open access article distributed under the Creative Commons Attribution License which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

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MDPI and ACS Style

Gomes, S.A.; Rebelo, M.J. A New Laccase Biosensor For Polyphenols Determination. Sensors 2003, 3, 166-175.

AMA Style

Gomes SA, Rebelo MJ. A New Laccase Biosensor For Polyphenols Determination. Sensors. 2003; 3(6):166-175.

Chicago/Turabian Style

Gomes, S. A.; Rebelo, M. J. 2003. "A New Laccase Biosensor For Polyphenols Determination." Sensors 3, no. 6: 166-175.

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