A lysine dehydrogenase-based electrode for biosensing of l-lysine

• Published in: Biosensors & bioelectronics Vol. 7; no. 5; pp. 323 - 327
• Main Authors: Dempsey, Eithne, Wang, Joseph, Wollenberger, Ulla, Ozsoz, Mehmet, Smyth, Malcolm R.
• Format: Journal Article
• Language: English
• Published: Lausanne Elsevier B.V 1992; Elsevier Science
• Subjects: Amino Acid Oxidoreductases - chemistry; amperometry; Biological and medical sciences; Biosensing Techniques; biosensor; Biosensors; Biotechnology; detection; electrochemistry; electrodes; Fundamental and applied biological sciences. Psychology; immobilized enzymes; L-lysine; Lysine - analysis; lysine dehydrogenase; Methods. Procedures. Technologies; Various methods and equipments; amperometry; l-lysine; biosensor; lysine dehydrogenase; Lysine dehydrogenase; Enzyme; Lysine; Biosensor; Amperometry; Enzyme electrode; Immobilized enzyme
• ISSN: 0956-5663; 1873-4235
• DOI: 10.1016/0956-5663(92)85027-8

An amperometric biosensor for l-lysine based on the recently isolated enzyme lysine dehydrogenase is described. Immobilization of the enzyme onto a platinum electrode is achieved via entrapment within a gelatin support on a cellulose membrane. Anodic detection (at 0.4V vs. Ag/AgCl) is facilitated by the presence of a redox-mediating ferricyanide ion. The effect of experimental variables such as pH, enzyme loading, applied potential, cofactor and mediator concentrations were evaluated in order to optimize the analytical performance. A detection limit of 7× 10 −8 m, and linearity up to 7× 10 −4 m are reported. The fast response permits adaptation for flow injection operation with good precision (RSD = 1.9%) and high sample throughput (40 samples per hour). The high specificity offered by this new enzyme is indicated by the lack of interference by other l-amino acids, alcohols or carbohydrates.