Flow-injection amperometric biosensor based on immobilized l-lysine-α-oxidase for l-lysine determination

Amperometric flow-inflection analytical system for quantitation of low L-lysine concentration was described. L-lysine-α-oxidase from Trichoderme sp. was immobilized by covalent linking on silica gel. The shift in oxygen concentration during enzymatic reaction was detected with a Clark membrane electrode. The rate of oxygen consumption was linearly dependent on L-lysine concentration over the 0, 20 - 5, 5 mM. Response time was 14 s, the total assay time about 2 min. The influences of pH, ionic strength and nature of the buffer on enzyme catalytic activity were tested. The analysis conditions were optimized. The immobilized L-lysine-α-oxidase retained the catalytic activity for about 5 months. © 1994, Taylor & Francis Group, LLC. All rights reserved.