title: Development of biosensors for the simultaneous determination of sucrose and glucose, lactose and glucose, and starch and glucose.
abstract: Sensors for the simultaneous determinations of sucrose and glucose, lactose and glucose, and starch and glucose were prepared by a combination of the enzyme system shown below and an oxygen electrode: The mechanism for separating the substrates with the proposed sensors is based on the time lag arising from reaction and diffusion. Invertase, beta-galactosidase, amyloglucosidase, mutarotase, and glucose oxidase were covalently immobilized on triacetyl cellulose membranes containing 1,8-diamino-4-aminomethyloctane. A glucose oxidase membrane, mutarotase membrane, three sheets of triacetyl cellulose membranes, and invertase, or beta-galactosidase or amyloglucosidase membrane were placed in that order on the tip of the oxygen electrode. Calibration curves for sucrose, lactose, and starch were linear up to 40 mM, 60-180 mM, and 10%, respectively. The simultaneous determination of sucrose and glucose, lactose and glucose, and starch and glucose was possible when the amount of glucose coexised was in the range of 2-16% sucrose, 2.8-8.3% lactose, or 0.1-1% starch. The relative errors were +/-4% for sucrose and +/-3% for lactose in 100 assays. The starch sensor was reused only five times. Each enzyme membrane was fairly stable for more than 10 days.
authors.affiliation: Department of Food science and Technology, Tokyo University of Fisheries, Minato-ku, Tokyo, Japan.
authors.forename: E
authors.initials: E
authors.lastname: Watanabe
authors.forename: M
authors.initials: M
authors.lastname: Takagi
authors.forename: S
authors.initials: S
authors.lastname: Takei
authors.forename: M
authors.initials: M
authors.lastname: Hoshi
authors.forename: C
authors.initials: C
authors.lastname: Shu-Gui