Use of laccase-modified electrode for amperometric detection of plant flavonoids

Abstract

In this study, laccase from Cerrena unicolor as a highly active enzyme was adsorptively immobilized on the surface of graphite electrode. The electrode inserted into flow-injection system served as a biosensor for detection of polyphenols, including flavonoids. We used catechin hydrate, epicatechin, epicatechin gallate, prodelphinidin, and caffeic acid as a target compounds in determination. The performed investigations demonstrate that laccase from white rot fungus C unicolor can be applied for the construction of biosensors useful for determination of flavonoids and related compounds in flow-injection system. Electrodes modified with laccase yield responses for both simple compounds (caffeic acid) and compounds with three or more phenolic and non-phenolic rings, although with different sensitivity. (C) 2004 Elsevier Inc. All rights reserved