Development of a laccase-modified electrode for amperometric detection of mono- and diphenols. The influence of enzyme storage method

Results are reported for biosensors based on two different preparations of the same enzyme, laccase from Cerrena unicolor, one lyophilized and one stored frozen at - 18degreesC, for monitoring phenolic compounds. The enzyme was adsorbed on graphite electrodes and these were used in a flow through wall jet cell connected to a flow injection set-up. The electrodes were used at - 50 mV vs. Ag\AgCl. The effect of PH, flow rate of the carrier buffer was investigated as well as the operational and storage stability. Biosensors based on the frozen enzyme preparation were shown to be superior for biosensor construction.