title: Glucose sensor using a phospholipid polymer-based enzyme immobilization method.
abstract: An electroenzymatic glucose sensor based on a simple enzyme immobilization technique was constructed and tested. The glucose sensor measures glucose concentrations as changes of oxygen concentrations induced by enzymatic reactions. The immobilizing procedure was developed with the purpose of producing wearable biosensors for clinical use. Two types of biocompatible polymers, 2-methacryloyloxyethyl phosphorylcholine (MPC) copolymerized with dodecyl methacrylate (PMD) and MPC copolymerized with 2-ethylhexyl methacrylate, were compared as a sensitive membrane of biosensors. The PMD enzyme membrane had a better response time. Linearity, reproducibility, effect of the concentrations of immobilized enzyme and drifts of sensor characteristics in long-term tests were also investigated. The linear characteristics were confirmed with glucose concentration from 0.01 to 2.00 mmol/l, with a coefficient of determination of 0.9999. The average output current for 1 mmol/l and the standard deviation were 0.992 and 0.0283 muA. Significant changes in the sensor's characteristics were not observed for 2 weeks when it was kept in a refrigerator at 4 degrees C. Because of the simple procedure, the enzyme immobilization method is not only useful for wearable devices but also other devices such as micro total analysis systems.
authors.affiliation: Department of Biomedical Devices and Instrumentation, Institute of Biomaterials and Bioengineering, Tokyo Medical and Dental University, 2-3-10 Kanda-Surugadai, Chiyoda-ku, Tokyo, 101-0062, Japan.
authors.forename: Hiroyuki
authors.initials: H
authors.lastname: Kudo
authors.forename: Tamon
authors.initials: T
authors.lastname: Yagi
authors.forename: Ming Xing
authors.initials: MX
authors.lastname: Chu
authors.forename: Hirokazu
authors.initials: H
authors.lastname: Saito
authors.forename: Nobuyuki
authors.initials: N
authors.lastname: Morimoto
authors.forename: Yasuhiko
authors.initials: Y
authors.lastname: Iwasaki
authors.forename: Kazunari
authors.initials: K
authors.lastname: Akiyoshi
authors.forename: Kohji
authors.initials: K
authors.lastname: Mitsubayashi
mesh_terms: D015374:Biosensing Techniques / Q000379:methods*; D002138:Calibration; D004800:Enzymes, Immobilized / Q000737:chemistry / Q000378:metabolism; D005947:Glucose / Q000032:analysis* / Q000378:metabolism*; D005949:Glucose Oxidase / Q000737:chemistry* / Q000378:metabolism*; D008689:Methacrylates / Q000737:chemistry; D015394:Molecular Structure; D010743:Phospholipids / Q000737:chemistry*; D010767:Phosphorylcholine / Q000031:analogs & derivatives / Q000737:chemistry; D011108:Polymers / Q000737:chemistry*; D015203:Reproducibility of Results
chemical_list: D004800:Enzymes, Immobilized; D008689:Methacrylates; D010743:Phospholipids; D011108:Polymers; C115846:dodecyl methacrylate; D010767:Phosphorylcholine; C070638:2-methacryloyloxyethyl phosphorylcholine; D005949:Glucose Oxidase; D005947:Glucose