A new interference-free lysine biosensor using a non-conducting polymer film

An electrochemical biosensor for the determination of lysine to be used for rapid evaluation of food quality has been developed. Platinum electrodes h ave been coated by electropolymerisation with 1,2-diaminobenzene( 1.2-DAB) using cyclic voltammetry. The reduction in the oxidation of interferents co mpared with the bare platinum electrode was 100% for ascorbic acid, 99% for acetaminophen and 99% for cysteine. The enzyme L-lysine-cu-oxidase was the n immobilised onto the polymer layer by passive adsorption and a calibratio n curve for lysine constructed. This gave a linear range of 1 x 10(-5) mol/ l to 1 x 10(-3) mol/l and a limit of detection of 2 x 10(-7) mel/l. (C) 199 8 Elsevier Science S.A. All rights reserved.