• Macromolecular Research
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• 제15권4호
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• pp.285-290
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• 2007

Ag nanoparticles were distributed onto polystyrene nanoparticle (PS-Ag) beads using two synthetic methodologies. In the first methodology, polystyrene (PS) beads were prepared via emulsion polymerization, with Ag nanoparticles subsequently loaded onto the surface of the PS beads. The polymerization of styrene was radiolytically induced in an ethanol (EtOH)/water medium, generating PS beads. Subsequently, Ag nanoparticles were loaded onto the PS beads via the reduction of Ag ions. The results from the morphological studies, using field emission transmission electron microscopy (FE-TEM), reveal the PS particles were spherical and nanosized, and the average size of the PS spherical particles decreased with increasing volume % of water in the polymerization medium. The size of the PS spherical particles increases with increasing radiation dose for the polymerization. Also, the amount of Ag nanoparticle loading could be increased by increasing the irradiation dose for the reduction of the Ag ions. In the second methodology, the polymerization of styrene and reduction of Ag ions were simultaneously performed by irradiating a solution containing styrene and Ag ions in an EtOH/water medium. Interestingly, the Ag nanoparticles were preferentially homogeneously distributed within the PS particles (not on the surface of the PS particles). Thus, Ag nanoparticles were distributed onto the surface of the PS particles using the first approach, but into the PS clusters of the particles via the second. The antimicrobial efficiency of a cloth coated with the Ag-PS composite nanoparticles was tested against bacteria, such as Staphylococcus aureus and Klebsiella pneumoniase, for 100 water washing cycles.

• 한국전기전자재료학회논문지
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• 제21권7호
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• pp.594-598
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• 2008

The metal catalyst particles which there is as impurities on a tip part of carbon nanotube (CNT) are not good to apply it to a nano-electronic device. It was very important the opening of CNT-tip to fix a target bio material and a material to accept in CNT in a biosensor, so we performed $HNO_3$ wet etching to remove the metal catalyst particle which there was on a tip part of CNT grown up in the study and observed the opened CNT-tip with etching time. We synthesized the CNTs using a HF-PECVD method and choses the CNT length of 700 nm for the application of nano-electronic device such as a biosensor etc.. We observed the opened CNT-tip with wet etching times of $HNO_3$ (10, 30, 60 min). From the results, we observed that the CNT-tip was opened with the increase of wet etching time lively. In case of CNTs etched during 60 min, we confirmed that there was not the ratio of Ni included in CNTsI as catalyst. Conclusively, in the case of CNT etched for 60 minutes, it is completely good for application of a biosensor and, in addition, the metal-free CNTs will contribute to the application of other nanoelectronic devices.

• Transactions on Electrical and Electronic Materials
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• 제9권4호
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• pp.163-168
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• 2008

Photonic crystal structures have been received considerable attention due to their high optical sensitivity. One of the techniques to construct their structure is the dip-pen lithography (DPN) process, which requires a nano-scale resolution and high reliability. In this paper, we propose a two dimensional photonic crystal array to improve the sensitivity of optical biosensor and DPN process to realize it. As a result of DPN patterning test, we have observed that the diffusion coefficient of the mercaptohexadecanoic acid (MHA) molecule ink in octanol is much larger than that in acetonitrile. In addition, we have designed and fabricated optical waveguides based on the mach-zehnder interferometer (MZI) for application to biosensors. The waveguides were optimized at a wavelength of 1550 nm and fabricated according to the design rule of 0.45 delta%, which is the difference of refractive index between the core and clad. The MZI optical waveguides were measured of the optical characteristics for the application of biosensor.

• 한국전기전자재료학회논문지
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• 제36권6호
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• pp.556-562
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• 2023

This paper presents the development and market trends of nano biosensors. These biosensors must possess high sensitivity and selectivity to effectively detect diseases. Presently, many research groups are focusing on the field-effect transistor aspect of nano biosensors, which can identify diseases such as Down syndrome, bladder cancer, breast cancer, and numerous other cancers, utilizing graphene and transition metal dichalcogenide materials. In the case of in-vitro diagnostics, the use of nano biosensors has been rapidly growing since the onset of the COVID-19 pandemic. This paper also discusses market trends and the outlook for both national and international enterprises engaged in the nano biosensor field. Nano biosensors are expected to play a beneficial and significant role soon, contributing to the early diagnosis of diseases and subsequently improving patient outcomes.

• 한국생물공학회:학술대회논문집
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• 한국생물공학회 2003년도 생물공학의 동향(XIII)
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• pp.701-705
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• 2003

Performance of an immunosensor can usually be assessed in terms of its analytical sensitivity and specificity. Sensitivity, i.e., the detection limit of analyte, is particularly determined by the amount of analyte molecules bound to the capture antibody immobilized onto a solid surface. In order to increase the binding complexes, we have investigated an immobilization method of antibody allowing for a molecular arrangement of the protein on a selective surface of a nano-patterned solid substrate. This has not been accomplished only by a surface treatment with a chemical, but also by fragmentation of immunoglobulin. Such approach would offer a protocol of antibody immobilization for the construction of nano-immunosensor and eventually improve the sensitivity of detection.

• 진공이야기
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• 제5권1호
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• pp.4-8
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• 2018

Many devices based on magnetism such as power generators and motors are frequently used in real life. Magnetic materials at nano-scale can be utilized as storage devices such as magnetic tapes and hard disk drives as well as spintronics. In addition to spintronics, magnetic biosensors are another interesting application of magnetic devices at nano-scale. Here, we briefly review magnetic nano-biosensors including Hall-effect sensors, giant magnetoresistive sensors, and tunnel magnetoresistive sensors for many biomedical applications.

• 전기화학회지
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• 제13권1호
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• pp.50-56
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• 2010

Multi-wall carbon nano-tube(MWCNT)를 이용해 screen printed carbon electrodes(SPCEs)을 제작하여 혈당센서의 선택성과 감도가 증가됨을 확인 할 수 있었다. 효소촉매반응을 위한 탄소전극으로의 전자이동의 매개체로 8족 금속 원소인 오스뮴을 중심금속으로 일차 아민을 포함하는 피리딘(pyridine) 리간드를 배위시켜 $[Os(dme-bpy)_2(4-aPy)Cl]^{+/2+}$를 합성하였다. 합성된 오스뮴 착물은 순환 전압전류법을 포함한 다양한 전기화학분석방법을 이용하여 전기적 성질을 조사하였다. 전기적 흡착방법을 이용하여 일차 아민을 갖는 착화합물을 전극위에 고정화 하였다. 오스뮴이 고정화된 MWCNT-SPCEs는 일반적인 carbon electrode보다 약 100배가량의 오스뮴이 흡착됨을 확인 할 수 있었다. (${\tau}_0=2.0\;{\times}\;10^{-9}\;mole/cm^2$) 마지막으로 당(Glucose)과 당 분해효소(Glucose Oxidase, GOx)에 의한 촉매반응의 전류를 확인하였고, 당 농도에 따라 선형 변화하는 전류의 양도 확인하였다.

• 한국정밀공학회지
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• 제25권11호
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• pp.22-29
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• 2008

• 공업화학
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• 제29권6호
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• pp.645-651
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• 2018

한국인의 암 사망률 1위를 차지하는 폐암은 발견되기 전까지 별다른 증상이 없어 환자는 병을 쉽게 인지하지 못하고, 기존의 진단법 또한 초기단계에는 적용이 어렵다. 해결책으로서, 분자수준에서의 체액분석을 폐암진단에 도입하는 방안이 제시되고 있다. 이를 위한 분석기기 가운데 대표적으로는 칩 기반 바이오센서가 있으며, 이 센서의 큰 장점으로는 고가의 분석장비나 숙련된 분석인력이 없이도 현장에서의 진단이 가능하다는 점이다. 본 미니총설에서는 폐암 진단에 활용가능한 혈액 내 바이오마커와 바이오칩 센서의 연구현황을 소개하고 이들의 발전가능성에 대해 논의하고자 한다.

• 공업화학
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• 제27권2호
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• pp.185-189
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• 2016

많은 생체 친화적인 센서들 중에서 avidin-biotin system은 높은 상호 특이적인 친화성으로 인하여 많은 생물학적인 응용 연구에 이용되어 왔다. 효과적인 avidin-biotin 바이오센서 개발을 위해 avidin-biotin 간의 상호 반응성을 증대시키기 위해서는 높은 표면적을 가지는 전극이 필요하다. 본 연구에서는 이러한 목적을 위해 gold nanorods electrode를 사용하였다. 전기화학적인 특성은 cyclic voltammetry (CV)와 electrochemical impedance spectroscopy (EIS)를 가지고 redox couple $[Fe(CN)_6]^{3-/4-}$를 사용하여 다양한 biotin의 농도에 따라 분석되었다. 결론적으로 nanorod의 전극은 1 ng/mL보다 낮은 biotin의 농도도 감지할 수 있음을 보였다.