• Title/Summary/Keyword: enzyme sensor

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Fabrication and Characteristics of FET Type Semiconductor Urea and Glucose Sensor Employing Photolithography Techniques (사진식각기술을 이용한 FET형 반도체 요소 및 포도당센서의 제조와 그 특성)

  • Cho, Byung-Woog;Kim, Chang-Soo;Seo, Hwa-Il;Sohn, Byung-Ki
    • Journal of Sensor Science and Technology
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    • v.1 no.2
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    • pp.101-106
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    • 1992
  • pH-ISFETs, the semiconductor pH sensors, were combined with immobilized enzyme membranes to prepare FET type urea and glucose sensors and its operational characteristics were investigated. Photolithography techniques were applied to immobilize enzymes on the $H^{+}$ sensing membrane of the pH-ISFET with photo-sensitive polymers, PVA-SbQ. Fabricated urea and glucose sensors could determine $0.5{\sim}50{\;}mg/dl$ urea concentrations and $10{\sim}1000{\;}mg/dl$ glucose concentrations, respectively.

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Detection of Food-Grade Hydrogen Peroxide by HRP-Biocomposite Modified Biosensors

  • Chang, Seung-Cheol
    • Journal of Food Hygiene and Safety
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    • v.32 no.6
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    • pp.447-454
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    • 2017
  • A new amperometric biosensor has been developed for the detection of hydrogen peroxide ($H_2O_2$). The sensor was fabricated through the one-step deposition of a biocomposite layer onto a glassy carbon electrode at neutral pH. The biocomposite, as a $H_2O_2$ sensing element, was prepared by the electrochemical deposition of a homogeneous mixture of graphene oxide, aniline, and horseradish peroxidase. The experimental results clearly demonstrated of that the sensor possessed high electrocatalytic activity and responded to $H_2O_2$ with a stable and rapid manners. Scanning electron microscopy, cyclic voltammetry, and amperometry were performed to optimize the characteristics of the sensor and to evaluate its sensing chemistry. The sensor exhibited a linear response to $H_2O_2$ in the range of 10 to $500{\mu}M$ concentrations, and its detection limit was calculated to be $1.3{\mu}M$. The proposed sensing-chemistry strategy and the sensor format were simple, cost-effective, and feasible for analysis of "food-grade $H_2O_2$" in food samples.

Expression of Plasma Membrane $H^ +-ATPase $ in the Roots of Plants Under Low Temperature (바이오센서에 의한 뿌리 원형질막에서의 $H^ +-ATPase $의 활성측정)

  • ;;;Etsuo Watanabe
    • KSBB Journal
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    • v.17 no.1
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    • pp.59-62
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    • 2002
  • The enzyme sensor for ATPase activity consisted of an immobilized membrane of two enzymes, purine nucloside phosphorylase (NP) and xanthine oxidase (XOD), and oxygen electrode. The $H^ +-ATPase $ rate of the plasma membranes increased by low root temperature. A cucumber and a pumpkin plasma membrane $H^ +-ATPase $$ activities measured by the proposed sensor system were in good agreement with the results obtained by a conventional UV spetrometer assay. One cycle of assay could be completed within 3 minutes.

A New Strategy for Determining Optimum pH of Isozymes

  • Yoon, Kil-Joong
    • Bulletin of the Korean Chemical Society
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    • v.25 no.7
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    • pp.997-1002
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    • 2004
  • A hydrogenperoxide sensor containing peroxidase extracted from horseradish was constructed and pH effect on its sensing ability was investigated. Current profiles of the biosensor with pH and the electrophoretic analysis showed that horseradish peroxidase consists of two isozymes. Assuming that it is a hypothetical twoisozyme mixture, the current profiles were deconvoluted into two Gaussians. Application of the new Michaelis-Menten equation connoting pH concept to this system enabled to find all the related dissociation constants of the isozyme-substrates and the isozyme-proton complexes and to determine pHs for the maximal isozyme activities.

Glucose Sensing Properties of Electrospinning-Synthesized ZnO Nanofibers (전기방사로 합성된 산화아연 나노섬유의 Glucose 감응특성)

  • Choi, Jong-Myoung;Byun, Joon-Hyuk;Kim, Sang Sub
    • Korean Journal of Materials Research
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    • v.25 no.12
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    • pp.655-658
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    • 2015
  • The development of glucose biosensors has been attracting much attention because of their importance in monitoring glucose in the human body; such sensors are used to diagnose diabetes and related human diseases. Thanks to the high selectivity, sensitivity to glucose detection, and relatively low-cost fabrication of enzyme-immobilized electrochemical glucose sensors, these devices are recognized as one of the most intensively investigated glucose sensor types. In this work, ZnO nanofibers were synthesized using an electrospinning method with polyvinyl alcohol zinc acetate as precursor material. Using the synthesized ZnO nanofibers, we fabricated glucose biosensors in which glucose oxidase was immobilized on the ZnO nanofibers. The sensors were used to detect a wide range of glucose from 10 to 700 M with a sensitivity of $10.01nA/cm^2-{\mu}M$, indicating that the ZnO nanofiber-based glucose sensor can be used for the detection of glucose in the human body. The control of nanograins in terms of the size and crystalline quality of the individual nanofibers is required for improving the glucose-sensing abilities of the nanofibers.

Determination of $K^+-, Ca^{2}+- and Mg^{2+}-$ATPase activities in Fish Muscle Protein by ATPase Biosensor (ATPase 센서를 이용한 어류근육 단백질의 $K^+-, Ca^{2}+- 및 Mg^{2+}-$ ATPase 활성의 측정)

  • 천병수;김희경
    • KSBB Journal
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    • v.11 no.5
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    • pp.518-523
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    • 1996
  • The sensor to determine ATPase activities was consisted of an immobilized enzyme membrane(purine nucloside phosphoryrase and xanthine oxidase) and an oxygen electrode. The proposed sensor was used for the determination of $K^+-, Ca^{2}+- and Mg^{2+}-$ATPase activities in several fish muscle proteins such as Thunnus albacares(Yellowfin tuna), Tetrapturus audax(Striped marlin), Prognichthys agoo(Japanese flyingfish), and Cypvinus carpio(Carp). $K^+-, Ca^{2}-$ATPase activities measured by the proposed sensor system were in good agreement with the results obtained by a conventional colorimetric assay. One cycle of assay could be completed within 3mlnutes.

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Highly Sensitive and Selective Glucose Sensor Realized by Conducting Polymer Modified Nanoporous PtZn Alloy Electrode

  • Jo, Hyejin;Piao, Hushan;Son, Yongkeun
    • Journal of Electrochemical Science and Technology
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    • v.4 no.1
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    • pp.41-45
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    • 2013
  • Platinum is a well known element which shows a significant electrocatalytic activity in many important applications. In glucose sensor, because of the poisoning effect of reaction intermediates and the low surface area, the electrocatalytic activity towards the glucose oxidation is low which cause the low sensitivity. So, we fabricate a nanoporous PtZn alloy electrode by deposition-dissolution method. It provides a high active surface and a large enzyme encapsulating space per unit area when it used for an enzymatic glucose sensor. Glucose oxidase was immobilized on the electrode surface by capping with PEDOT composite and PPDA. The composite and PPDA also can exclude the interference ion such as ascorbic acid and uric acid to improve the selectivity. The surface area was determined by cyclic voltametry method and the surface structure and the element were analyzed by Scanning Electron Microscope (SEM) and Energy Dispersive X-ray spectroscopy (EDX), respectively. The sensitivity is $13.5{\mu}A/mM\;cm^2$. It is a remarkable value with such simply prepared senor has high selectivity.

Direct treatment on live and cancer cells & process innovation of bio-sensor using atmospheric pressure plasma system with low-temperature arc-free unit

  • Lee, Keun-Ho;Lee, Hae-Ryong;Jun, Seung-Ik;Bahn, Jae-Hoon;Baek, Seung-J.
    • Proceedings of the Korean Vacuum Society Conference
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    • 2010.02a
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    • pp.43-43
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    • 2010
  • We have characterized the parametric and functional properties of live cell and cancer cell according to plasma treatment conditions using Atmospheric Pressure (AP) Plasma with uniquely designed low temperature arc-free unit. AP plasma system showed very highly efficient capabilities of reacting and interfacing directly with live and cancer cells. The parametric results with the types of gases, applied power, applied gap, and process times on cells will be presented in accordance with functional studies of the works. The growth of cancer cells is directly influenced by AP plasma exposure with evaluating plasma conditions in several human cancer cells and understanding how plasma exposure alters molecular signaling pathways. The cells exhibit a slower or faster growth rates compared with untreated cells, depending on the cell types. These results strongly support the conclusion that alterations in one or more of each gene are responsible, at least in part, for plasma-induced apoptosis in cancer cells. In addition, it also will be presented that AP plasma has an important role for the improvement of sensor performance due to excellent interface property between enzyme and metal electrode for bio sensor manufacturing process.

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Development of Biomolecular Device Using Biomolecular Film Part 1: Optical Biosensor to Detect the Ethanol Using Langmuir-Blodgett Film of Eilzyme Molecules (생체분자막을 이용한 생물분자소자의 개발 제1부 :효소분자 LB막을 이용한 에탄올 측정용 광학 바이오센서)

  • 최정우;배주연지용이원홍
    • KSBB Journal
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    • v.10 no.1
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    • pp.105-112
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    • 1995
  • The fiber-optic biosensor using enzyme-immobilized Langmuir-Blodgett film is developed fort the measurement of ethanol. The enzyme, alcohol dehydrogenase, is immobilized at the molecular level on the arachidic acid monolayer using Langmuir-Blodgett film technique. Based on the ordered multisubstrate mechanism, the immobilized enzyme kinetics is investigated. The optical sensing system is proposed, and sensor signal is proportional to ethanol concentration and is related wish the number of enzyme layers. As the number of deposited LB film layer increases up to 20 1ayers, the high ethanol concentration of 45mM can be measured without the saturation of signal. Surface pressure-area isotherm is measured for the three-different charged-lipids. Arachidic acid is the most suitable for the adsorption of alcohol dehydrogenase based on electrostatic force.

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