• 대한전기학회:학술대회논문집
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• 대한전기학회 2008년도 제39회 하계학술대회
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• pp.1295-1296
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• 2008

Hydrogen peroxide ($H_2O_2$) biosensor is one of the most developing sensors because this kind of sensors is highly selective and responds quickly to the specific substrate. Hemoglobin (Hb) has been used as ideal biomolecules to construct hydrogen peroxide biosensors because of their high selectivity to $H_2O_2$. The direct electron transfer of Hb has widely investigated for application in the determination of $H_2O_2$ because of its simplicity, high selectivity and intrinsic sensitivity. An electrochemical detection for hydrogen peroxide was investigated based on immobilization of hemoglobin on DNA/Fe(pyterpy)$^{2+}$ modified gold electrode. The pyterpy monolayers were firstly an electron deposition onto the gold electrode surface of the quartz crystal microbalance (QCM). It is offered a template to attach negatively charged DNA. The fabrication process of the electrode was verified by quartz crystal analyzer (QCA). The experimental parameters such as pH, applied potential and amperometric response were evaluated and optimized. Under the optimized conditions, this sensor shows the linear response within the range between $3.0{\times}10^{-6}$ to $9.0{|times}10^{-4}$ M concentrations of $H_2O_2$. The detection limit was determined to be $9{\times}10^{-7}$ M (based on the S/N=3).

• Korean Chemical Engineering Research
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• 제44권1호
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• pp.1-9
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• 2006

생물체를 구성하는 세포의 기능과 구성요소 간 상호작용 메커니즘을 인공적으로 모방하여 바이오물질 박막으로 구성된 바이오소자는 의료 진단, 신약 스크리닝, 전자소자, 생물공정, 환경오염 물질 측정 등 다양한 산업 분야에 응용되고 있다. 단백질, DNA, 바이오색소, 세포 등의 생체물질을 칩 상에 고집적으로 배열하여 구성된 바이오 소자로서 바이오 전자소자(생물분자 광다이오드, 바이오 정보저장소자, 바이오 전기발광 소자), DNA칩, 단백질칩, 및 세포칩 등이 개발되어 오고 있다. 생체물질 고정화 기술, 마이크로 및 나노수준의 패터닝기술, 소자 구성 기술, 바이오 멤스 기술의 융합을 통해 바이오소자는 구현되며, 최근에는 나노기술의 적용에 의하여 나노바이오소자도 구현이 가능하다. 본 논문에서는 현재까지 개발된 다양한 바이오소자의 제작 기술과 응용에 대하여 소개하고 향후의 발전 방향에 대하여 다룬다.

• KSBB Journal
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• 제17권3호
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• pp.213-227
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• 2002

To date, the majority of biosensor technologies use binding components such as enzymes antibodies, nucleic acids and protein ligands. In contrast, the goal underlying the use of cells and tissues of animals and plants for a sensor system is to obtain systems capable of extracting information based on the biological activity, mechanisms of action and consequences of exposure to a chemical or biological agent of interest. These systems enable the interrogation of more complex biological response and offer the potential to gather higher information content from measuring physiologic and metabolic response. In these articles, same of the recent trends and applications of microbial biosensors in environmental monitoring and for use in food and fermentations have been reviewed. This endeavor presents many technological challenges to fabricate new microbial biosensors for other scientific field.

• Biotechnology and Bioprocess Engineering:BBE
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• 제9권2호
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• pp.118-126
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• 2004

Recombinant E.coli ACV 1003 (recA::lacZ) releasing ${\beta}$-galactosidase by a SOS regulon system, when exposed to DNA-damaging compounds, have been used to effectively monitor endocrine disruptors. Low enzyme activity of less than 10 units/mL, corresponding to a $\mu\textrm{g}$/L(ppb) range of an endocrine disruptor (tributyl tin, bisphenol A. etc.), can be rapidly determined, not by a conventional time-consuming and tedious enzyme assay, but by an alternative interferometric biosensor. Heavily boron-doped porous silicon for application as an interferometer, was fabricated by etching to form a Fabry-Perot fringe pattern, which caused a change in the refractive index of the medium including ${\beta}$-galactosidase. In order to enhance the immobilization of the porous silicon surface, a calyx crown derivative (ProLinker A) was applied, instead of a conventional biomolecular affinity method using biotin. This resulted in a denser linked formation. The change in the effective optical thickness versus ${\beta}$-galactosidase activity, showed a linear increase up to a concentration of 150 unit ${\beta}$-galactosidase/mL, unlike the sigmoidal increase pattern observed with the biotin.

• Journal of the Optical Society of Korea
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• 제10권3호
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• pp.130-142
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• 2006

Lab-on-a-chip technology is attracting great interest because the miniaturization of reaction systems offers practical advantages over classical bench-top chemical systems. Rapid mixing of the fluids flowing through a microchannel is very important for various applications of microfluidic systems. In addition, highly sensitive on-chip detection techniques are essential for the in situ monitoring of chemical reactions because the detection volume in a channel is extremely small. Recently, a confocal surface enhanced Raman spectroscopic (SERS) technique, for the highly sensitive biological analysis in a microfluidic sensor, has been developed in our research group. Here, a highly precise quantitative measurement can be obtained if continuous flow and homogeneous mixing condition between analytes and silver nano-colloids are maintained. Recently, we also reported a new analytical method of DNA hybridization involving a PDMS microfluidic sensor using fluorescence energy transfer (FRET). This method overcomes many of the drawbacks of microarray chips, such as long hybridization times and inconvenient immobilization procedures. In this paper, our recent applications of the confocal Raman/fluorescence microscopic technology to a highly sensitive lab-on-a-chip detection will be reviewed.

• Genomics & Informatics
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• 제14권4호
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• pp.216-221
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• 2016

Osteoporotic fractures (OFs) are critical hard outcomes of osteoporosis and are characterized by decreased bone strength induced by low bone density and microarchitectural deterioration in bone tissue. Most OFs cause acute pain, hospitalization, immobilization, and slow recovery in patients and are associated with increased mortality. A variety of genetic studies have suggested associations of genetic variants with the risk of OF. Genome-wide association studies have reported various single-nucleotide polymorphisms and copy number variations (CNVs) in European and Asian populations. To identify CNV regions associated with OF risk, we conducted a genome-wide CNV study in a Korean population. We performed logistic regression analyses in 1,537 Korean subjects (299 OF cases and 1,238 healthy controls) and identified a total of 8 CNV regions significantly associated with OF (p < 0.05). Then, one CNV region located on chromosome 20q13.12 was selected for experimental validation. The selected CNV region was experimentally validated by quantitative polymerase chain reaction. The CNV region of chromosome 20q13.12 is positioned upstream of a family of long non-coding RNAs, LINC01260. Our findings could provide new information on the genetic factors associated with the risk of OF.

• 미생물학회지
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• 제50권1호
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• pp.40-45
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• 2014

전 세계적으로 친환경 농업을 위해 식물생장촉진 근권세균을 이용한 미생물 비료에 대한 관심이 증가하고 있는데 투여하는 세균을 식물 근권에 보다 장기간 잔류시키기 위해 식물생장 촉진능이 있는 균주를 alginate bead에 고정화하여 식물생장을 조사하였다. 발아된 토마토 유묘에 Arthrobacter woluwensis ED를 $1{\times}10^6$ cells/g 로 처리하고 30일 재배 후 자라난 토마토의 shoot와 뿌리 길이 및 습윤과 건조중량을 측정한 결과 비접종 대조군과 비교하여 균주 현탁액 접종군은 각각 36.2, 59.0, 51.1과 37.5%씩 유의성 있게 증가하였으며 고정화 균주 접종군은 각각 42.0, 67.4, 62.5와 60.4%씩 유의성 있게 증가하였다. 고정화 균주 접종군은 균주 현탁액 접종군에 비하여 각각 6, 8, 11과 23% 증가하였다. 접종 균주가 식물 근권에서 유지되는 양상을 관찰하기 위해 denaturing gradient gel electrophoresis를 이용하여 토양세균 군집을 분석하였는데 균주 현탁액 접종군에서 ED 균주의 DNA band intensity는 접종일로부터 1주일까지 가장 높게 나타났으나 그 이후로 감소하여 접종 2주 후 비접종 대조군과 비슷한 band intensity를 나타내었다. 반면, 고정화 균주 접종군의 ED 균주 band intensity는 접종일로부터 초기에는 비접종 대조군과 비슷하였으나 이후 급격하게 증가하여 계속 높게 유지되어 3주까지 band intensity가 현탁액 접종군 보다 높았다. 따라서 alginate에 A. woluwensis ED를 고정하여 적용하는 방법이 현탁액 적용보다 식물 근권에 균주의 공급을 효과적으로 유지하면서 식물생장을 더욱 촉진하는 것으로 나타났다.

• 대한기계학회논문집B
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• 제41권1호
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• pp.63-67
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• 2017

일반적인 세포 배양 기술은 평평한 표면에 세포 부착을 위한 화학적, 생화학적 표면처리를 하는 것이 기본이지만, 요즘 들어 마이크로나 나노 크기의 구조체를 형성하여 세포 부착을 하는 연구들이 많이 진행되고 있다. 본 연구에서는 전도성 고분자인 피롤과 나노임프린트 기술을 이용하여 300 nm 선 패턴과 150 nm 원기둥 패턴의 나노구조체 제작 후 대표적인 암세포인 HeLa 세포를 배양하여, 주사전자현미경과 공초점 현미경을 이용하여 세포의 부착 특성을 연구하였다. 상용 페트리 접시와 평면 피롤에서는 세포들이 부정형의 형태로 부착 및 배양되었지만, 선폭 300 nm 선패턴 상에서는 길이 방향으로 세포가 부착되고 세포 내의 핵과 액틴 역시 배열되어 있고, 지름 150 nm 원기둥 패턴 상에서는 단일 세포로 고정되고 세포 내 액틴은 방사상으로 나노구조체에 고정되어 있는 것을 확인할 수 있었다.