High-throughput flow-injection analysis of glucose and glutamate in food and biological samples by using enzyme/polyion complex-bilayer membrane-based electrodes as the detectors.
The concentration of glucose was determined by a combination of flow injection analysis (FIA) with amperometric enzyme sensor detection. The enzyme sensor was prepared by immobilizing glucose oxidase on an electrode coated with a polyion complex layer consisting of poly-L-lysine and poly(4-styrenesulfonate). The inner, polyion complex layer was useful for preventing electrochemical interferents (e.g., L-ascorbic acid, uric acid and acetaminophen) from reaching the electrode surface, which was effective for reducing the interferential responses upon the injections of biological and food samples. The sensor-based system could be used for the determination of glucose from 10 microM to 3 mM with the sampling rate of 180 h-1, and was stable for more than 2 months. An FIA system for determining L-glutamic acid (3 microM-0.5 mM) was also prepared by using an enzyme electrode based on a glutamate oxidase/polyion complex-bilayer as the detector.
Mizutani
F
F
National Institute of Bioscience and Human Technology, Ibaraki, Japan. mizutani@nibh.go.jp
Sato
Y
Y
Hirata
Y
Y
Yabuki
S
S
D015374:Biosensing Techniques; D005504:Food Analysis; D005947:Glucose / Q000032:analysis*; D018698:Glutamic Acid / Q000032:analysis*; D007477:Ions; D008567:Membranes, Artificial
D007477:Ions; D008567:Membranes, Artificial; D018698:Glutamic Acid; D005947:Glucose