• 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 Food Hygiene and Safety
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• v.34 no.6
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• pp.509-518
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• 2019

To monitor the levels of antimicrobials, allergens, pathogens and other contaminants in foods meant for human consumption, it is imperative to have quick, accurate and low-cost tests. Advanced techniques (e.g. label-free biosensor assays) have been developed over the past 10-15 years to solve some of these problems. As biosensors, immunosensors can provide real-time measurements, a high degree of automation, and improved throughput and sensitivity. By comparison with conventional methods, immunosensors are less expensive, less sophisticated physicochemical instruments that require less time for analysis while also being more user-friendly. In this review, we discuss our current knowledge about immunosensors, their strengths and weaknesses, as well as the future of these biosensors in food safety.

• Journal of Food Hygiene and Safety
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• v.32 no.2
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• pp.83-88
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• 2017

We introduced disposable amperometric immunosensors for the detection of Sildenafil and Vardenafil (SDF/VDF) based on screen printed carbon electrodes. The developed immunosensors were used as a non-competitive sandwich-type enzyme immunoassay with a horseradish peroxidase label. The sensors were constructed on screen printed carbon electrodes by the simple electrochemical deposition of a reduced graphene oxide and chitosan (ErGO-CS) composite. To evaluate the sensing chemistry and optimize the sensor characteristics, a series of electrochemical experiments were carried out including electrochemical impedance spectroscopy, cyclic voltammetry and amperometry. The sensors showed a linear response to SDF/VDF concentrations in a range from 100 pg/mL to 300 ng/mL. The lower detection limit was calculated to be 55 pg/mL, the sensitivity was calculated to be $1.02{\mu}Ang/mL/cm^2$, and the sensor performance exhibited good reproducibility with a relative standard deviation (RSD) of 7.1%. The proposed sensing chemistry strategy and the sensor format can be used as a simple, cost-effective, and feasible method for the in-field analysis of SDF/VDF in functional or health supplement food samples.

• Biotechnology and Bioprocess Engineering:BBE
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• v.5 no.6
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• pp.407-412
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• 2000

Environmental biosensors and related techniques for monitoring organochlorines, endocrine disrupting chemicals and cyanobacterial toxins are described. The practical requirements for an ideal environmental biosensor are analyzed. Specific case studies for environmental applications are reported for triazines, chlorinated phenols, PCBs, microcystins, and endocrine disrupting chemicals. A new promising approach is reported for microcystins and alkylphenols that utilize electrooptical detection.

• Bulletin of the Korean Chemical Society
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• v.33 no.3
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• pp.839-842
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• 2012

We report for the first time the synthesis of niobium dioxide nanowires on a sapphire substrate by chemical vapor transport method. We identified single crystalline nature of as-synthesized nanowires by scanning electron microscopy and transmission electron microscopy. Niobium dioxide nanowires with their large surface-to-volume ratio and high activities can be employed for electrochemical catalysts and immunosensors. The Raman spectrum of niobium dioxide nanowires also confirmed their identity.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.5 no.1
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• pp.87-92
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• 2004

This review focuses on the developed and the being developed environmental sensors in particular biological sensors. As well as discussing the classification and some main principles, presenting current trend of the environmental sensors is given. Two main categories are immunosensors and catalytic sensors. In addition to those. DNA or RNA sensors or protein based sensors are discussed. Some crucial examples of the applications of such sensors are given to show how the sensor technology it used for environmental and biological monitoring, biomarkers of exposure.

• 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.

• Journal of Biomedical Engineering Research
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• v.26 no.5
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• pp.271-282
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• 2005

There are strong demands for accurate, fast, and inexpensive devices in the medical diagnostic laboratories, such as biosensors and chemical sensors. Biosensors can provide the reliable and accurate informations on the desired biochemical parameters, which is an essential prerequisite for a patient before going for a treatment. They can be used for continuous measurements of metabolites, blood cations, gases, etc. Of these, electrochemical biosensors play an important role in the improvement of public health, because rapid detection, high sensitivity, small size, and specificity are achievable for clinical diagnostics. In this paper, the clinical applications with electrochemical biosensors are reviewed. An attempt is also made to highlight some of the trends that govern the research and developments of the important biosensors that are associated to clinical diagnosis.

• Journal of Sensor Science and Technology
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• v.20 no.6
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• pp.434-438
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• 2011

A portable surface plasmon resonance(SPR) based immunosensor using thiolated protein G and protein G was developed for the detection of immunoglobulin G(IgG). The protein G has specific affinity with Fc fragment of IgG and was thiolated by 2-Iminothiolane for introduction of thiol groups. Anti-IgG, bovine serum albumin(BSA), and IgG have been sequently injected after surface modification of gold sensor chip with protein G and thiolated protein G. The output signal was increased with the injection of each protein and the actual signal was measured by subtracting signal of reference channel from signal of sample injected channel. The experimental results showed the higher detection capability of IgG using thiolated protein G compared with protein G. From these results, we can conclude that the current surface modification technique and the portable SPR sensor system can be applied to various immunosensors for diagnosis.

• Journal of Sensor Science and Technology
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• v.20 no.1
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• pp.35-39
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• 2011

A disposable electrochemical immunosensor system has been developed for the detection of herbicide in aqueous samples. Disposable screen printed carbon electrodes(SPCE) were used as basic electrodes and an enzyme, horseradish peroxidase (HRP), and anti-herbicide antibodies was immobilised on to the working electrode of SPCE by using avidin-biotin coupling reactions. An herbicide-glucose oxidase conjugates have been used for the competitive immunoreaction with sample herbicides. The enzymatic reaction between the conjugated glucose oxidase and glucose added generates hydrogen peroxide, which was reduced by the peroxidase immobilised. The latter process caused an electrical current change, due to direct re-reduction of peroxidase by a direct electron transfer mechanism, which was measured to determine the herbicides in the sample. The optimal operational condition was found to be: $20\;{\mu}gl-1$ deglycosylated avidin loading to the working electrode and working potential +50 mV vs. Ag/AgCl. The total assay time was 15 min after sample addition. The detection limits for herbicides, atrazine and simazine, were found to be 3 ppb and 10 ppb, respectively.