Amperometric determination of laminarin using immobilized beta-1,3-glucanase.
A novel sensor system equipped with a reactor packed with beads containing immobilized beta-1,3-glucanase and glucose oxidase was developed for the amperometric determination of laminarin concentration. The proposed sensor system consisted of a reactor, an oxygen electrode, a flow cell, a pump, a buffer tank, and a recorder. The measurement was performed with a flow injection system. The optimum conditions for the sensor system were as follows: transfer solution, pH 7.0; 0.1 M phosphate buffer solution; flow rate, 0.15 ml/min; and sample volume, 50 microl. The response was correlated to the laminarin concentration. The calibration curve was obtained between 50 and 0.5 mg/ml laminarin (R2 = 0.994). The detection limit was 50 microg/ml laminarin (the ratio of signal/noise = 3). The relative standard deviations were 2.0% (n = 15) and 2.5% (n = 15) for 0.4 and 1.0 mg/ml laminarin solutions, respectively. One assay was completed within 5 min. Results suggest that the sensor can be used not only for the analysis of seaweed and health-enhancing foods but also for monitoring the initial pollution of the marine environment.
Miyanishi
Nobumitsu
N
Department of Food Science and Technology, Tokyo University of Fisheries, 4-5-7 Konan, Minato-ku, Tokyo 108-8477, Japan.
Inaba
Yohei
Y
Okuma
Hirokazu
H
Imada
Chiaki
C
Watanabe
Etsuo
E
D015374:Biosensing Techniques / Q000295:instrumentation* / Q000379:methods; D020099:Coated Materials, Biocompatible / Q000737:chemistry; D004563:Electrochemistry / Q000295:instrumentation* / Q000379:methods; D004795:Enzyme Stability; D004800:Enzymes, Immobilized / Q000737:chemistry; D004867:Equipment Design; D019544:Equipment Failure Analysis; D017022:Flow Injection Analysis / Q000295:instrumentation* / Q000379:methods; D004693:Glucan Endo-1,3-beta-D-Glucosidase / Q000737:chemistry*; D005936:Glucans; D007795:Laminaria / Q000737:chemistry*; D011134:Polysaccharides / Q000032:analysis* / Q000737:chemistry; D011522:Protons; D012680:Sensitivity and Specificity
D020099:Coated Materials, Biocompatible; D004800:Enzymes, Immobilized; D005936:Glucans; D011134:Polysaccharides; D011522:Protons; C008247:laminaran; D004693:Glucan Endo-1,3-beta-D-Glucosidase