title: Fiber-Optic Fluoroimmunoassay System with a Flow-Through Cell for Rapid On-Site Determination of Escherichia coli O157:H7 by Monitoring Fluorescence Dynamics.
abstract: Dynamic fluoroimmunoassay with a flow-through system using optical fiber probes consisting of polystyrene was developed and applied to a quantitative detection of E. coli O157:H7. The system measures E. coli as fluorescence of sandwich-type immune complexes formed by capture antibodies immobilized on the surface of the probe, E. coli cells, and fluorescently labeled detection antibodies. Excitation was carried out using an evanescent wave from the probe. Resulting fluorescence recoupled into the probe was detected by a photodiode. The assay system was constructed with a flow cell which was available for sequential injection of experimental reagents. In vitro characterization was performed using the flow cell, and the calibration range of E. coli O157:H7 was from 10(3) to 10(7) cells/mL. The measurement for each sample was completed within 12 min. Furthermore, it was also possible to estimate the concentrations of E. coli O157:H7 by the increasing rate of fluorescence during binding reaction of detection antibodies to antigens. This minimized the time for measurement down to 6 min. The system is suitable for rapid and direct determination for microorganisms or bacteria in food, clinical, and environmental sources.
authors.affiliation: Department of Advanced Sciences and Technology for Biomedical Sensors, Graduate School of Medical and Dental Sciences, Tokyo Medical and Dental University, 1-5-45 Yushima, Bunkyo-ku, Tokyo 113-8549, Japan; E-Mail: miya.bdi@tmd.ac.jp ; 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; E-Mails: arakawa.bdi@tmd.ac.jp (T.A.); kudo.bdi@tmd.ac.jp (H.K.).
authors.forename: Kumiko
authors.initials: K
authors.lastname: Miyajima
authors.affiliation: Graduate School of Bionics, Tokyo University of Technology, 1404-1, Katakura-machi, Hachioji-shi, Tokyo 192-0982, Japan; E-Mails: t.koshida@hotmail.co.jp (T.K.); yano@bs.teu.ac.jp (K.Y.).
authors.forename: Tomoyuki
authors.initials: T
authors.lastname: Koshida
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; E-Mails: arakawa.bdi@tmd.ac.jp (T.A.); kudo.bdi@tmd.ac.jp (H.K.).
authors.forename: Takahiro
authors.initials: T
authors.lastname: Arakawa
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; E-Mails: arakawa.bdi@tmd.ac.jp (T.A.); kudo.bdi@tmd.ac.jp (H.K.).
authors.forename: Hiroyuki
authors.initials: H
authors.lastname: Kudo
authors.affiliation: Department of Mechanical Engineering, Tokyo National Collage of Technology, 1220-2 Kunugida-machi, Hachioji-shi, Tokyo 193-0997, Japan; E-Mail: h.saito@tokyo-ct.ac.jp.
authors.forename: Hirokazu
authors.initials: H
authors.lastname: Saito
authors.affiliation: Graduate School of Bionics, Tokyo University of Technology, 1404-1, Katakura-machi, Hachioji-shi, Tokyo 192-0982, Japan; E-Mails: t.koshida@hotmail.co.jp (T.K.); yano@bs.teu.ac.jp (K.Y.).
authors.forename: Kazuyoshi
authors.initials: K
authors.lastname: Yano
authors.affiliation: Department of Advanced Sciences and Technology for Biomedical Sensors, Graduate School of Medical and Dental Sciences, Tokyo Medical and Dental University, 1-5-45 Yushima, Bunkyo-ku, Tokyo 113-8549, Japan; E-Mail: miya.bdi@tmd.ac.jp ; 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; E-Mails: arakawa.bdi@tmd.ac.jp (T.A.); kudo.bdi@tmd.ac.jp (H.K.).
authors.forename: Kohji
authors.initials: K
authors.lastname: Mitsubayashi
keywords: E. coli O157:H7; flow cell; fluorescence; immunoassay; optical fiber