Biosensor for the determination of l-lysine

✍ Scribed by E. Vrbová; M. Marek; E. Ralys

• Publisher: Elsevier Science
• Year: 1992
• Tongue: English
• Weight: 384 KB
• Volume: 270
• Category: Article
• ISSN: 0003-2670
• DOI: 10.1016/0003-2670(92)80099-s

✦ Synopsis

A biosensor for the determination of L-lysine was prepared, consisting of a Clark-type oxygen sensor and a convenient support with an immobilized enzyme system fixed to its surface. L-Lysine-a-oxidase was co-immobilized with catalase via the Ugi reaction using glutaraldehyde and cyclohexyl isocyanide either on a partially hydrolysed nylon net or on the preactivated or native collagen membrane. The consumption of oxygen was detected by the oxygen sensor. Hydrogen peroxide was decomposed by catalase to increase the sample throughout. The enzyme electrode prepared was tested from the viewpoint of its substrate specificity, pH and temperature effect on the enzyme activity and characterized by the specific and relative activity of the immobilized enzyme system. The linear range of biosensor response to the substrate was 6.7 × 10-6-6.7 x 10 -4 M; the apparent Michaelis constant (1.3 mM) and the stability of biosensor were also determined. The enzyme electrode was used for the determination of L-lysine in wheat extracts.