Suginami-ku, Japan
Suginami-ku, Japan

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Nakajima H.,Tokyo Metroplitan University | Okuma Y.,Kyushu University | Morioka K.,Tokyo Metroplitan University | Miyake M.,Kyushu University | And 13 more authors.
Journal of Separation Science | Year: 2011

A fluorescence detection system for a microfluidic device using an organic light-emitting diode (OLED) as the excitation light source and a charge-coupled device (CCD) as the photo detector was developed. The OLED was fabricated on a glass plate by photolithography and a vacuum deposition technique. The OLED produced a green luminescence with a peak emission at 512 nm and a half bandwidth of 55 nm. The maximum external quantum efficiency of the OLED was 7.2%. The emission intensity of the OLED at 10 mA/cm 2 was 13 μW (1.7 mW/cm 2). The fluorescence detection system consisted of the OLED device, two band-pass filters, a five microchannel poly(dimethylsiloxane) (PDMS) microfluidic device and a linear CCD. The fluorescence detection system was successfully used in a flow-based enzyme-linked immunosorbent assay on a PDMS microfluidic device for the rapid determination of immunoglobulin A (IgA), a marker for human stress. The detection limit (S/N=3) for IgA was 16.5 ng/mL, and the sensitivity was sufficient for evaluating stress. Compared with the conventional 96-well microtiter plate assay, the analysis time and the amounts of reagent and sample solutions could all be reduced. Copyright © 2011 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.


Hemmi A.,Mebius Advanced Technology Ltd. | Hemmi A.,Tokyo Metroplitan University | Usui T.,Tokyo Metroplitan University | Moto A.,Tokyo Metroplitan University | And 8 more authors.
Journal of Separation Science | Year: 2011

A surface plasmon resonance (SPR) sensor on a compact disk (CD)-type microfluidic device was developed to miniaturize the elements of a complete analytical system, pump and valves. The CD-type microfluidic device was fabricated by attaching a polydimethylsiloxane disk plate that contained microchannels and reservoirs to a flat polycarbonate disk plate that contained grating films with a thin layer of Au. The optical system of the SPR sensor and the theory for its operation are based on the principle of a grating coupled-type SPR. The sample and reagent solutions in the reservoirs on the CD-type microfluidic device were sequentially introduced into the detection chamber by centrifugal force generated by the rotation of the microfluidic device. The variation of resonance wavelength was dependent on the refractive index of the sample solution. This CD-type SPR sensor was successfully used in an immunoassay of immunoglobulin A (IgA). The anti-IgA, blocking reagent, sample and washing solution in the reservoirs were sequentially introduced into the detection chamber by changing the frequency of rotation of the microfluidic device. IgA in the sample solution was adsorbed to the anti-IgA immobilized on the Au thin layer in the detection chamber and was then detected by the SPR sensor. Copyright © 2011 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.


Miyake M.,Kyushu University | Nakajima H.,Tokyo Metroplitan University | Hemmi A.,Mebius Advanced Technology Ltd. | Yahiro M.,Institute of System | And 6 more authors.
Talanta | Year: 2012

The performance of an organic thin film photodiode (OPD), fabricated from a hetero-junction comprised of two layers of C60 and a phthalocyanine-Cu(II) complex was evaluated by detecting the chemiluminescence generated from the reaction of luminol with horseradish peroxidase in the presence of H2O2, and the fluorescence from resorufin, as an optical detector. The photocurrent of the OPD was linear with respect to the power of light from a commercial LED. The sensitivity of the OPD was sufficient for detecting chemiluminescence with a power 0.1 μW/cm2. The OPD was successfully used in a flow-immunoassay for IgA, a marker of human stress, in which a sandwich immunoassay was carried out on the microchip and the fluorescence from resorufin, produced by the enzymatic reaction, was detected. The detection limits for resorufin and IgA were 5.0 μM and 16 ng/mL, respectively. The photosensitivity of the OPD remained relatively constant for a minimum of one year. © 2012 Elsevier B.V. All rights reserved.


Zhan J.,Kyushu University | Furui K.,Konica Minolta | Nakajima H.,Tokyo Metroplitan University | Kaneki N.,Muroran Institute of Technology | And 4 more authors.
Analytical Sciences | Year: 2016

A portable-type surface plasmon resonance (SPR) sensor, composed from a new optical system for multi-sensing, has been developed to apply to environment analysis, clinical diagnosis etc., where many samples are desired to be analyzed at high throughput. The optical system of the sensor consists of a light-emitting diode, a pair of cylindrical lenses, a pair of collimator lenses, a correction lens, a prism, a polarizer and a linear CCD sensor with 2048 pixels. Reflected light from a sensor chip of the width of 6 mm at a certain incident angle was detected by ca. 618 pixels of the linear CCD sensor as an SPR sensor signal. An SPR sensor signal at a specified incident angle is controllable for optimization by adjusting the position of the CCD sensor. A sensor chip having a 30-stripe linear pattern (100 μm width/stripe) was prepared. The spatial resolution as well as the performance of the sensor were evaluated by using sucrose solutions. As a result, the acquisition of SPR sensor signals from 30 sensing points was successfully achieved with a spatial resolution of 100 μm (distance between 2 sensing points). A lower detection limit of ca. 3.2-5.5 × 10-5 RIU with a standard deviation of ±4.5% was obtained by averaging the signals from 6-7 pixels of the CCD sensor per one sensing stripe. 2016. © The Japan Society for Analytical Chemistry.


Yoshida Y.,Kyoto Institute of Technology | Nakamura S.,Kyoto Institute of Technology | Uchida J.,Kyoto Institute of Technology | Henmi A.,Mebius Advanced Technology Ltd. | Maeda K.,Kyoto Institute of Technology
Journal of Electroanalytical Chemistry | Year: 2013

A novel thin-layer electrolysis flow cell based on the ion transfer at the liquid|liquid interface was proposed for the absolute determination of a sub-nanomole ionic species. By using the conducting polymer-coated electrode as an electrode in organic phase, the flow cell was developed as a laminate structure with a thin aqueous layer and a thin organic layer, which were set between an Ag/AgCl electrode and the conducting polymer-coated electrode. Its simple structure made it possible to miniaturize the flow cell, and the required sample volume was reduced to only 1 μl. In the present electrolysis cell, both quantitative extraction and quantitative back-extraction of total amount of the ionic species were achieved. This advantage was applied to two methods for absolute determination. One is that by flow injection method, and the other is that by pre-concentration into the thin organic phase followed by back-extraction of the species from the thin Org to the thin aqueous phase (i.e., the stripping technique). In these methods, coulometrical determination of sub-nanomol ionic species was realized without a calibration curve. © 2013 Elsevier B.V. All rights reserved.


Guo S.,Kyushu University | Nakano K.,Kyushu University | Nakajima H.,Tokyo Metroplitan University | Uchiyama K.,Tokyo Metroplitan University | And 5 more authors.
Pure and Applied Chemistry | Year: 2012

A simple and pump-free chemiluminescence immunoassay based on a compact disc (CD)-type microfluidic platform for the determination of alkylphenol polyethoxylates (APnEOs) is described. The method is based on a competitive immunoreaction of the anti- APnEOs antibody immobilized on the magnetic microbeads between APnEOs and horseradish peroxidase (HRP)-labeled APnEOs in the sample solution. The luminol solution containing H 2O 2 and enhancer is caused to flow from one reservoir in the platform to another by appropriate adjustment of the speed of the rotation of the disc. The detection limit was similar to that reported in our previous paper, i.e., 10 ppb according to IC 80. © 2012 IUPAC.


Morioka K.,Tokyo Metroplitan University | Nakajima H.,Tokyo Metroplitan University | Hemmi A.,Mebius Advanced Technology Ltd. | Iida S.,Tokyo Metroplitan University | And 4 more authors.
Bunseki Kagaku | Year: 2016

We have developed a two-dimensional surface plasmon resonance (SPR) sensor using multiplied beam-splitting optics. In this study, we evaluated immunoassays by the SPR sensor. As a result, we could measure the change of the reflected-light intensity in real time, which is based on the immobilization of an antibody onto the surface of the sensor chip, the adsorption of a blocking reagent onto the surface, and specific bonding of the antigen to the antibody immobilized on the sensor chip. The calibration curve for IgA was linear under a concentration of 6.0 μg mL−1, and a quantitative immunoassay was successfully accomplished by the SPR sensor. We also fabricated a sensor chip in which anti-IgA, anti-IgG and anti-IgM were immobilized on the detection point in the flow channel on the sensor chip, respectively. We then evaluated measurements of IgA, IgG and IgM using the sensor chip. When a sample solution containing IgA was introduced into the flow channel, the reflected light intensity at the detection point at which anti-IgA was immobilized dramatically increased, whereas the reflected light intensity at the detection point at which anti-IgG or anti-IgM was immobilized did not change. Similarly, in the case of IgG and IgM, the reflected light intensity only increased at the detection point at which corresponding antibody was immobilized. These results indicate that a simultaneous immunoassay by the SPR sensor should be possible. © 2016 The Japan Society for Analytical Chemistry.


Morioka K.,Tokyo Metroplitan University | Hemmi A.,Mebius Advanced Technology Ltd. | Zeng H.,Tokyo Metroplitan University | Uchiyama K.,Tokyo Metroplitan University | Nakajima H.,Tokyo Metroplitan University
17th International Conference on Miniaturized Systems for Chemistry and Life Sciences, MicroTAS 2013 | Year: 2013

An enzyme-linked immunosorbent assay on a compact disk (CD)-type microfluidic device was developed for the simple and rapid determination of IgA in human saliva, a marker of human stress. The sample, reagent and washing solutions (IgA, IIRP-labeled anti-IgA and Amplex®; Red containing H 2O2) in the reservoirs on the CD-type microfluidic device were sequentially introduced into the detection chamber immobilized with anti-IgA and BSA by the centrifugal force generated by the rotation of the CD-type microfluidic device. To determine IgA, the enzymatic product, resorufin, was detected using a novel fluorescence detection system in conjunction with an OLED and a CCD. Copyright © (2013) by the Chemical and Biological Microsystems Society All rights reserved. All rights reserved.


Hemmi A.,Mebius Advanced Technology Ltd | Hemmi A.,Kyushu University | Mizumura R.,Tokyo Metroplitan University | Kawanishi R.,Tokyo Metroplitan University | And 5 more authors.
Sensors (Switzerland) | Year: 2013

A novel two dimensional surface plasmon resonance (SPR) sensor system with a multi-point sensing region is described. The use of multiplied beam splitting optics, as a core technology, permitted multi-point sensing to be achieved. This system was capable of simultaneously measuring nine sensing points. Calibration curves for sucrose obtained on nine sensing points were linear in the range of 0-10% with a correlation factor of 0.996-0.998 with a relative standard deviation of 0.090-4.0%. The detection limits defined as S/N = 3 were 1.98 × 10-6-3.91 × 10-5RIU. This sensitivity is comparable to that of conventional SPR sensors. © 2013 by the authors; licensee MDPI, Basel, Switzerland.


PubMed | Mebius Advanced Technology Ltd.
Type: Evaluation Studies | Journal: Journal of separation science | Year: 2011

A surface plasmon resonance (SPR) sensor on a compact disk (CD)-type microfluidic device was developed to miniaturize the elements of a complete analytical system, pump and valves. The CD-type microfluidic device was fabricated by attaching a polydimethylsiloxane disk plate that contained microchannels and reservoirs to a flat polycarbonate disk plate that contained grating films with a thin layer of Au. The optical system of the SPR sensor and the theory for its operation are based on the principle of a grating coupled-type SPR. The sample and reagent solutions in the reservoirs on the CD-type microfluidic device were sequentially introduced into the detection chamber by centrifugal force generated by the rotation of the microfluidic device. The variation of resonance wavelength was dependent on the refractive index of the sample solution. This CD-type SPR sensor was successfully used in an immunoassay of immunoglobulin A (IgA). The anti-IgA, blocking reagent, sample and washing solution in the reservoirs were sequentially introduced into the detection chamber by changing the frequency of rotation of the microfluidic device. IgA in the sample solution was adsorbed to the anti-IgA immobilized on the Au thin layer in the detection chamber and was then detected by the SPR sensor.

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