Flow-injection analysis of phenols at a graphite electrode modified with co-immobilised laccase and tyrosinase

The kinetic parameters of the oxidation reaction of phenolic compounds by molecular oxygen catalysed by fungal laccase have been studied. An amperometric biosensor for detection of phenols in environmental analysis is proposed. The enzymes laccase and tyrosinase were co-immobilised by adsorption onto a spectrographic graphite electrode. The bienzyme electrode was used as a sensor in a single-line flow-injection system. The analysis is based on the amperometric detection of the enzymatic reaction products at a potential of -0.05 V vs. AgAgCl. The experimental parameters were optimised. The joint use of laccase and tyrosinase in the analytical procedure allows the detection of a large group of phenolic compounds.