title: Development of a package-free transparent disposable biosensor chip for simultaneous measurements of blood constituents and investigation of its storage stability.
abstract: A package-free transparent disposable biosensor chip was developed by a screen-printing technique. The biosensor chip was fabricated by stacking a substrate with two carbon electrodes on its surface, a spacer consisting of a resist layer and an adhesive layer, and a cover. The structure of the chip keeps the interior of the reaction-detecting section airtight until use. The chip is equipped with double electrochemical measuring elements for the simultaneous measurement of multiple items, and the reagent layer was developed in sample-feeding path. The sample-inlet port and air-discharge port are simultaneously opened by longitudinally folding in two biosensor units with a notch as a boundary. Then the shape of the chip is changed to a V-shape. The reaction-detecting section of the chip has a 1.0 microl sample volume for one biosensor unit. Excellent results were obtained with the chip in initial simultaneous chronoamperometric measurements of both glucose (r=1.00) and lactate (r=0.998) in the same samples. The stability of the enzyme sensor signals of the chip was estimated at ambient atmosphere on 8 testing days during a 6-month period. The results were compared with those obtained for an unpackaged chip used as a control. The package-free chip proved to be twice as good as the control chip in terms of the reproducibility of slopes from 16 calibration curves (one calibration curve: 0, 100, 300, 500 mg dl(-1) glucose; n=3) and 4.6 times better in terms of the reproducibility of correlation coefficients from the 16 calibration curves.
authors.affiliation: School of Bionics, Tokyo University of Technology, Hachioji, Tokyo, Japan. nakamura@bs.teu.ac.jp
authors.forename: Hideaki
authors.initials: H
authors.lastname: Nakamura
authors.forename: Kana
authors.initials: K
authors.lastname: Tohyama
authors.forename: Masanori
authors.initials: M
authors.lastname: Tanaka
authors.forename: Shouji
authors.initials: S
authors.lastname: Shinohara
authors.forename: Yuichi
authors.initials: Y
authors.lastname: Tokunaga
authors.forename: Fumiyo
authors.initials: F
authors.lastname: Kurusu
authors.forename: Satoshi
authors.initials: S
authors.lastname: Koide
authors.forename: Masao
authors.initials: M
authors.lastname: Gotoh
authors.forename: Isao
authors.initials: I
authors.lastname: Karube
mesh_terms: D015374:Biosensing Techniques; D001774:Blood Chemical Analysis / Q000295:instrumentation / Q000379:methods*; D001786:Blood Glucose / Q000032:analysis; D015190:Blood Glucose Self-Monitoring; D047369:Chromatin Immunoprecipitation; D019064:Product Packaging
chemical_list: D001786:Blood Glucose