• 한국생물공학회:학술대회논문집
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• 2001.11a
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• pp.859-862
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• 2001

For the development of preferable immunosensor and protein chip, the viologen Langmuir-Blodgett (LB) multilayer was fabricated on the surface, and then protein A was adsorbed on the proposed viologen LB film by electrostatic attractive force. The Immunoglobulin G (IgG) labeled with fluorescence marker was self-assembled on the fabricated protein A film. The topographies of the deposited films were investigated by using atomic force microscope (AFM). The immobilization of IgG was verified by fluorescence spectrum. Such structures can be used as sublayers for various kinds of IgG immobilization toward immunosensors and protein chip.

• 한국생물공학회:학술대회논문집
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• 2003.10a
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• pp.683-686
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• 2003

While genetically modified organisms (GMOs) are producing in many countries, issues related to safeties of GMOs as foods for human have risen. Because of such potential problems, the development of an indication system regarding GMO content contained in foods has been required. Particularly, an immune-chip, as widely demanded diagnostic tool for functional, structural analyses of proteins, has been investigated to simultaneously measure different analytes. We have developed methods for immobilizing antibody on glass surfaces as substrate and for generating chemiluminometric signals.

• Agricultural and Biosystems Engineering
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• v.5 no.1
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• pp.21-24
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• 2004

Antibody based biosensors are very selective and ultra-sensitive. Antigen-antibody reactions have been used in immunoassays. In this research, a biosensor which uses antigen-antibody reaction was developed to measure and detect rat IgG. Because the antigen-antibody reaction is a physical bounding between antigen and antibody, there are several ways to measure an antigen-antibody reaction. Among the methods, impedance analysis has short measuring time and possibilities of analyzing various properties of the reaction using frequency analysis. Rat IgG could be detected with developed biosensor and impedance analyzer. The biosensor showed good repeatability and availability of detecting concentration changes of rat IgG.

• 한국환경농학회:학술대회논문집
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• 2009.07a
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• pp.187-199
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• 2009

We present real.time, rapid detection of Mycoplasma pneumonia in phosphate buffered saline (PBS) inside a Y.channel polydimethylsiloxane (PDMS) microfluidic device by means of optical fiber monitoring of latex immunoagglutination. The latex immunoagglutination assay was performed with serially diluted Mycoplasma pneumonia solutions using highly carboxylated polystyrene particles of 390nm and 500nm diameter conjugated with monoclonal anti. Mycoplasma pneumonia . Proximity optical fibers were located around the viewing cell of the device, which were used to measure the increase in 45${\b{o}}$ forward light scattering of the immunoagglutinated particles. The detection limit was less than 50 $pgml^{-1}$ both for 390nm and 500nm microspheres with the detection time less than 90 seconds.

• Journal of Sensor Science and Technology
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• v.19 no.2
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• pp.142-148
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• 2010

We have compared and investigated the detection capabilities of antibody of immunoglobulin G(anti-IgG) immobilized by protein G and N-hydroxysuccinimide(NHS) at the end of the self-assembled monolayer(SAM). Surface plasmon resonance(SPR) sensor has been utilized to measure the interaction between biomolecules. After formation of the protein G and SAM, anti-IgG, bovine serum albumin(BSA) and IgG has been sequently injected. Through the reponse of the SPR, we can conclude that the protein G immobilized anti-IgG better than the SAM. In addition, IgG detection capability of the anti-IgG immobilized by the protein G showed better performance compared with that immobilized by the SAM.

• KSBB Journal
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• v.17 no.2
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• pp.121-136
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• 2002

Immunosensors are of great interest because of their potential utility as specific, simple, label-free, direct detection means and provision of reduction in size, cost and time of analysis comparing with conventional immunoassay. In the last two decades, many reports have been published on the use of immunosensors for a wide range of applications to clinical diagnostics, pharmaceutical chemistry, environmental monitoring, biotechnology and food industries. There are also numerous transduction techniques developed such as electrochemical techniques, piezoelectric crystal, and surface plasmon resonance receiving much attention for the direct monitoring of immune reactions at solid surfaces. In this article, the principles, characteristics, structures, fonctions and clinical applications of immunosensors were reviewed

• Journal of Sensor Science and Technology
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• v.18 no.2
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• pp.160-167
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• 2009

In this study, secondary antibody-containing quartz crystal microbalance(QCM) sensor chip was prepared and utilized for the detection of human and bovine haptoglobin. Anti-goat immunoglobulin G antibody, which is a secondary antibody capable of capturing primary antibodies raised in goat, was immobilized through the reaction between hydrazide and aldehyde group prepared on the QCM surface and antibody respectively. The resulting sensor chip showed higher stability in the repeated surface regeneration with acidic dissociation solution as well as requiring lower amount of primary antibody when compared to the protein G sensor chip. The secondary antibody sensor chip was applied for the estimation of bovine and human haptoglobin.

• Journal of Electrochemical Science and Technology
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• v.2 no.1
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• pp.57-61
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• 2011

This paper describes an electrochemical immunoassay for simple, fast and quantitative detection of a urinary hippuric acid which is one of major biological indicator in toluene-exposed humans. The electrochemical system of immunoassay was based on the directly osmium complex conjugated with hippuric acid. With the competition between free hippuric acid (HA) and the osmium-hippuric acid conjugate (Os-HA) to bind with antibody hippuric acid (Anti-HA) coated onto gold nanoparticles, the electrical signals were proportional to urinary hippuric acid (HA) in the range of 0.01-5 mg/mL which is enough range to be used for in-field or point-of-care (POC) diagnosis. The proposed electrochemical method can be extended to the applications to detect a wide range of different small molecules in the field of health care.

• Bulletin of the Korean Chemical Society
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• v.33 no.5
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• pp.1485-1490
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• 2012

An electrochemical immunoassay based on osmium-hippuric acid (HA) conjugate films onto the electrode is presented for the detection of urinary HA. This is the first report on the use of the oxidative electropolymerization of 5-amino-1,10-phenanthroline (5-$NH_2$-phen) for immobilizing an antigen, osmium-conjugated HA. As a redox mediator, [Os(5-amino-1,10-phenanthroline)$_2$(4-aminomethylpyridine-HA)Cl]$^{+/2+}$ (Os-phen-HA) was successfully synthesized and electropolymerized onto the screen-printed carbon electrodes (SPCEs). The interaction between osmium-HA conjugate films and antibody-HA ($anti$-HA) was performed by cyclic voltammetry (CV) and differential pulse voltammetry (DPV). The electrical signals were linearly proportional to urinary HA in the range of 0.1-5.0 mg/mL, which is sufficient for use as an immunosensor using a cutoff concentration of 2.0 mg/mL in urine samples. The proposed electrochemical immunoassay method can be extended to various applications for detecting a wide range of different small antigens in the health care area.

• The Journal of the Acoustical Society of Korea
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• v.23 no.1
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• pp.1-7
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• 2004

We developed SH-SAW sensors to detect protein molecules in liquid solutions applying a particular antibody thin film on the delay line of transverse SAW devices. The antibody investigated was human-immune-globulin G (HigG) to hold the antigens (anti-HigG) in the protein solution. We fabricated the sensor generating 100 MHz with the piezoelectric single crystal LiTaO₃. We measured the frequency change of the sensor by adding the anti-body concentration on SAM (self assembled monolayer) deposited on the Au layer. The sensor showed stable response to the mass loading effects of the anti-HigG molecules with the sensitivity up to 10.8 ng/ml/Hz at noise level 400 Hz below.