title: Chemiluminometric sensor for simultaneous determination of L-glutamate and L-lysine with immobilized oxidases in a flow injection system.
abstract: A chemiluminometric flow-through sensor for simultaneous determination of L-glutamate (Glu) and L-lysine (Lys) in a single sample has been developed. Immobilized uricase, immobilized peroxidase, support material, coimmobilized glutamate oxidase/peroxidase, support material, and coimmobilized lysine oxidase/peroxidase were packed sequentially in a transparent PTFE tube, and the tube was placed in front of a photomultiplier tube as a flow cell. A three-peak recording was obtained by one injection of the sample solution. The peak height of the first peak was due to the concentrations of urate and other reductants in the sample; the immobilized uricase was used to decompose urate, and the hydrogen peroxide produced was decomposed with a luminol-hydrogen peroxide reaction by immobilized peroxidase. The peak heights of the second and third peaks were free from the interferences from the reductants and were dependent only on the concentrations of Glu and Lys, respectively. Calibration graphs for Glu and Lys were linear at 40-1,000 and 50-1,200 nM, respectively. The sampling rate was 11/h without carryover. The sensor was stable for two weeks. The sensor system was applied to the simultaneous determination of Glu and Lys in serum.
authors.affiliation: Department of Applied Chemistry and Biotechnology, Faculty of Engineering, Yamanashi University, Kofu, Japan.
authors.forename: Nobutoshi
authors.initials: N
authors.lastname: Kiba
authors.forename: Takao
authors.initials: T
authors.lastname: Miwa
authors.forename: Masaki
authors.initials: M
authors.lastname: Tachibana
authors.forename: Kazue
authors.initials: K
authors.lastname: Tani
authors.forename: Hitoshi
authors.initials: H
authors.lastname: Koizumi
mesh_terms: D016477:Artifacts; D015374:Biosensing Techniques; D004800:Enzymes, Immobilized / Q000737:chemistry*; D017022:Flow Injection Analysis; D018698:Glutamic Acid / Q000032:analysis*; D008163:Luminescent Measurements; D008239:Lysine / Q000032:analysis*; D010088:Oxidoreductases / Q000737:chemistry*; D015203:Reproducibility of Results; D014527:Uric Acid / Q000032:analysis
chemical_list: D004800:Enzymes, Immobilized; D014527:Uric Acid; D018698:Glutamic Acid; D010088:Oxidoreductases; D008239:Lysine