• Journal of Electrochemical Science and Technology
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• 제2권2호
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• pp.124-129
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• 2011

A simple process of fabricating micropillar structure and its influence upon enhancing electrochemical biosensor response were studied in this work. Conducting polymer PEDOT was used as a base material in formulating a composite with PVA. Micro porous PC membrane filter was used as a template for the micropillar of the composite on ITO electrode. This structure could provide plenty of encapsulating space for enzyme species. After dosing enzyme solution into this space, Nafion film tent was cast over the pillar structure to complete the micropillar cavity structure. In this way, the encapsulation of enzyme could be accomplished without any chemical modification. The amount of enzyme species was easily controllable by varying the concentration of the dosing solution. The more amount of enzyme is stored in the sensor, the higher the electrochemical response is produced. One more reason for the sensitivity improvement comes from the large surface area of the micropillar structure. Application of 0.7 V produced the best current response under the condition of pH 7.4. This biosensor showed linear response to the glucose in 0.1~1 mM range with the average sensitivity of $14.06{\mu}A/mMcm^2$. Detection limit was 0.01 mM based on S/N = 3.

• 공업화학
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• 제22권5호
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• pp.522-525
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• 2011

본 연구에서는, enzyme-linked immunosorbent assay (ELISA)와 면역크로마토그래픽 기법을 결합하여 Staphylococcus aureus 검출을 위한 면역스트립을 제작하였다. 면역스트립은 4개의 서로 다른 기능을 가진 멤브레인을 이용하여 만들어졌다. 니트로셀룰로오스 멤브레인은 항체와의 결합력이 높기 때문에, 포획항체를 고정화하였고, 다공성 멤브레인들을 통하여 모세관 현상으로 인해 시료흐름을 유도하였다. 효소반응에 의해 생성된 발색신호는 디지털카메라와 자체 제작된 소프트웨어를 이용하여 정성, 정량분석 하였다. 최적의 분석조건 하에서 30 min 이내에 $2.7{\times}10^4{\sim}2.7{\times}10^7CFU/mL$ 범위의 S. aureus 농도를 측정할 수 있었다.

• 약학회지
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• 제40권1호
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• pp.72-77
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• 1996

Penicillin sensor was manufactured by immobillizing penicillinase with glutaraldehyde on the $H^+$-selective membrane based on PVC-COOH-TDDA. This membrane was not inter fered by $K^+$ ion in Pc-G potassium salt. When enzyme was immobilized with glutaraldehyde, the PVC-COOH matrix was more effective than PVC matrix. Calibration curve calculated from Nernst equation was not linear. But potential was relative to concentration of Pc-G. And maximal potentiometric velocity was also relative to concentration of Pc-G. Therefore, it may be applied to Michaelis-Menten equation. The penicillin sensor was useful for determination of Pc-G at concentration of 0.1~10mM level.

• 공업화학
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• 제25권5호
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• pp.538-543
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• 2014

시판 고추냉이 과산화효소를 대치하기 위하여 탄소반죽에 담배 잎을 고정시켜 과산화수소 감응 센서를 제작하고 그것의 감응성을 살펴보았다. 얻어진 10여 개 이상의 전극 파라미터는 효소전극이 실험 전위영역에서 정량적으로 특이성을 발휘하고 있음을 보여주었다. 특히 작은 대칭인자(${\alpha}$, 0.21)는 전극반응 속도가 전극전위의 변화에 매우 민감한 것을 보여주었다. 이런 실험적 사실들은 효소전극이 과산화수소 센서로서 정상적으로 기능을 발휘하고 있으며 담배 과산화효소가 시판 효소를 대체할 수 있음을 보여주는 것이었다.

• 반도체디스플레이기술학회지
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• 제19권4호
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• pp.116-120
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• 2020

In this paper, we developed an electrochemical glucose sensor strip using a paper substrate. The paper glucose sensor strip is eco-friendly because it uses paper as a substrate, and it has the advantage that it can be manufactured only with four printing, drying and cutting processes. The paper glucose sensor is significantly simplified by the production process than the conventional glucose sensors because the production of only four printing on the paper substrate. In this paper, eco-friendly tracing paper was used to develop a paper glucose sensor strip, and screen-printing technology was used to form a carbon/silver electrode, insulating layer and glucose oxidase(GOD) layer. The developed paper glucose sensor strip has a flat structure with a size of 30 × 4.6 ㎟, and blood injection is a type of direct contact with the exposed enzyme layer above the strip. In this paper, the performance of paper glucose sensor strips was evaluated by analyzing the cyclic voltammetry(CV) and chronoamperometry(CA) characteristics.

• 대한전기학회:학술대회논문집
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• 대한전기학회 1987년도 전기.전자공학 학술대회 논문집(I)
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• pp.490-492
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• 1987

Urea-Sensor was fabricated by immobilizing urease on ISFET's gate using BSA(bovine serum albumin) and glutaraldehyde, and its characteristics were examined. This sensor showed approximately linear characteristic in the urea concentration range of $3{\times}10^{-5}-10^{-9}$ (g/ml). Fast response time was obtained and minute amounts of expensive enzyme were used in comparison to general electrode type biosensors.

• Biomolecules & Therapeutics
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• 제16권1호
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• pp.1-8
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• 2008

Mitochondria are important sensor of apoptosis. $H_2O_2-induced$ cell death rate was enhanced by serum deprivation. In this study, we investigated whether serum deprivation using 0.5 or 3 % FBS induces apoptotic cell death through mitochondrial enzyme activation as compared to 10 % FBS. Apoptotic cell death was observed by chromosome condensation and the increase of sub-G0/G1 population. Serum deprivation reduced cell growth rate, which was confirmed by the decrease of S-phase population in cell cycle. Serum deprivation significantly increased caspase-9 activity and cytochrome c release from mitochondria into cytosol. Serum deprivation-induced mitochondrial changes were also indicated by the increase of ROS production and the activation of mitochondrial enzyme, succinate dehydrogenase. Mitochondrial enzyme activity increased by serum deprivation was reduced by the treatment with rotenone, mitochondrial electron transport inhibitor. In conclusion, serum deprivation induced mitochondrial apoptotic cell death through the elevation of mitochondrial changes such as ROS production, cytochrome c release and caspase-9 activation. It suggests that drug sensitivity could be enhanced by the increase of mitochondrial enzyme activity in serum-deprived condition.

• KSBB Journal
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• 제17권2호
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• pp.158-161
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• 2002

본 연구에서는 화학무기, 농약 등에 사용되는 신경독성물질인 유기인화합물의 측정을 위하여 유기인화합물의 효소반응 저해작용을 이용한 광바이오센서장치의 시제품을 제작하였다. 효소반응을 위하여 효소로는 신경세포의 필수효소인 acetylcholinesterase, acetylthiocholine iodide을 사용하였으며 효소반응의 저해제인 유기인화합물로는 paraoxon을 사용하였다. 센서의 폭정원리는 유기인화합물에 의해 저해된 효소반응정도를 효소반응의 생성물인 아세트산의 정량적 측정으로 분석하였으며, pH에 의하여 최대 흡광파장의 변화가 일어나는 litmus를 사용하여 흡광도 측정으로 아세트산의 정량분석을 수행하였다. 광바이오센서 시제품의 제작은 광원으로 고취도 LED와 광세기 측정을 위한 photodiode로 구성하였으며, 제작된 센서를 이용한 실험결과로부터 0 ppm에서 2 ppm의 paraoxon 농도에서 구성된 센서시스템의 선형적 신호 변화를 관찰하였다. 이상의 실헐결과로부터 광바이오센서 시제품은 2분의 반응시간으로 신속하고 정확한 유기인화합물의 정량분석이 가능함을 확인하였다.

• 센서학회지
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• 제27권3호
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• pp.156-159
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• 2018

We developed a glucose sensor using glucose dehydrogenase flavin adenine dinucleotide (GDH-FAD). The structure of the three-layer glucose sensor was simplified, in which a single-layer design was used to lower the unit cost, and GDH-FAD was used to increase the measurement reliability. GDH-FAD has less impact on the 20 interfering substances that affect blood glucose measurement, such as galactose and maltose compared to glucose oxidase (GOD), and is not affected by the oxygen saturation; therefore, it is possible to measure both arterial or venous blood and thus less susceptibility to hematocrit. In this study, we developed a single-layer glucose sensor strip with low hematocrit effect using the GDH-FAD enzyme, and measured and evaluated the performance.

• 폴리머
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• 제33권2호
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• pp.111-117
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• 2009

본 연구를 통해 역이온 영동(reverse iontophoresis)을 이용한 무채혈 혈당 측정시스템의 patch sensor에 사용되는 효소 고정형 수화젤의 생체적합성 여부를 확인하고자 하였다. 아크릴레이트 계열의 단량체를 사용하여 일정한 unit의 효소가 고정된 수화젤을 합성하였다. 합성된 수화젤의 물성분석을 위해 FT-IR spectrometer를 이용하여 구조분석을 하고 DSC를 이용하여 열적 안정성을 확인하였다. 또한, UV-Vis spoctrophotometer를 이용하여 표준품 대비 50% 이상의 효소 활성도를 확인하였다. 표면의 효소 고정화 확인을 위해 SEM을 이용하여 확인한 결과 효소가 고정화되어 있음을 확인하였다. 수화젤은 환자의 피부에 직접적으로 접촉됨으로써 접촉 시 무해성을 평가하기 위하여, ISO-10993에 의하여 세포독성(cytotoxicity), 피내반응(intracutaneous reactivity), 피부자극(skin irritation) 및 감작성(maximization sensitization) 시험을 실시하였고 이를 통해 생체적합성이 우수하다는 것을 확인하였다.