Hexagonally close packed Langmuir-Blodgett films from monodispersed silica nanoparticles.

Kim, Jin-Ho,Kim, Hyo-Sop,Lee, Jae-Hyeok,Choi, Sung-Wook,Cho, Yong-Jin,Kim, Jae-Ho American Scientific Publishers 2009 Journal of Nanoscience and Nanotechnology Vol.9 No.12

<P>This report demonstrates a novel procedure to produce hexagonally close packed nanoparticle film using the Langmuir-Blodgett (LB) technique. The LB technique has advantages over previously reported techniques, such as high reproducibility, formation of large area films with low-cost capable of producing a large number of hexagonally close packed nanoparticle films at a single process. In this method, a monolayer of mono-dispersed silica nanoparticles was spread on the surface of water and then transferred it onto a gold sputtered glass substrate or silicon wafer. The silica particles used for fabrication of LB films were synthesized by the modified Stöber method. In present work, we synthesized 300 +/- 5 nm sized silica particles. A large area of hexagonally close packed nanoparticle films fabricated by the LB technique was confirmed by AFM and FE-SEM. Furthermore, we demonstrate fabrication of over 34 hexagonally close packed nanoparticle LB films on glass substrates with area of 18 x 18 mm2 from a single process.</P>

Analysis of wavelength shift versus surface coverage of proteins on nano-porous silicon immunosensor.

Kim, Hyo-Sop,Kim, Jin-Ho,Lee, SooSuk,Choi, Sung-Wook,Koh, Kwangnak,Kim, Jae-Ho American Scientific Publishers 2009 Journal of Nanoscience and Nanotechnology Vol.9 No.12

<P>The Fabry-Perot fringe pattern is determined by wavelength shifts in interferometric reflectance spectroscopy, which is a function of the refractive index (n) and thickness (l) of the porous silicon (PSi). In this paper, we demonstrated the shifts of wavelength as systematic controlling of adsorbed concentration of a protein on the PSi substrate. In order to correlate the wavelength shift of the Fabry-Perot fringe pattern with the protein adsorption, adsorbed concentrations of avidin (66 kDa) on the PSi substrate were measured by three independent methods: first, by means of bromophenol blue, which is applied to surface-confined avidin; second, with fluorescence intensity measurement of FITC-tagged avidin; and finally by utilizing Time of Flight-Secondary Ion Mass Spectrometry (TOF-SIMS). It was found that the wavelength shift is directly proportional to the surface-adsorbed avidins over the wide range of surface concentration on the PSi substrate, with a rate of 0.1 nm red-shift at avidin concentration change of 1.0 fmol/cm2.</P>

Water-soluble mercury ion sensing based on the thymine-Hg²⁺-thymine base pair using retroreflective Janus particle as an optical signaling probe

Chun, Hyeong Jin,Kim, Saemi,Han, Yong Duk,Kim, Dong Woo,Kim, Ka Ram,Kim, Hyo-Sop,Kim, Jae-Ho,Yoon, Hyun C. Elsevier 2018 Biosensors & bioelectronics Vol.104 No.-

<P><B>Abstract</B></P> <P>Herein, we report an optical sensing platform for mercury ions (Hg<SUP>2+</SUP>) in water based on the integration of Hg<SUP>2+</SUP>-mediated thymine-thymine (T-T) stabilization, a biotinylated stem-loop DNA probe, and a streptavidin-modified retroreflective Janus particle (SA-RJP). Two oligonucleotide probes, including a stem-loop DNA probe and an assistant DNA probe, were utilized. In the absence of Hg<SUP>2+</SUP>, the assistant DNA probe does not hybridize with the stem-loop probe due to their T-T mismatch, so the surface-immobilized stem-loop DNA probe remains a closed hairpin structure. In the presence of Hg<SUP>2+</SUP>, the DNA forms a double-stranded structure with the loop region via Hg<SUP>2+</SUP>-mediated T-T stabilization. This DNA hybridization induces stretching of the stem-loop DNA probe, exposing biotin. To translate these Hg<SUP>2+</SUP>-mediated structural changes in DNA probe into measurable signal, SA-RJP, an optical signaling label, is applied to recognize the exposed biotin. The number of biospecifically bound SA-RJPs is proportional to the concentration of Hg<SUP>2+</SUP>, so that the concentration of Hg<SUP>2+</SUP> can be quantitatively analyzed by counting the number of RJPs. Using the system, a highly selective and sensitive measurement of Hg<SUP>2+</SUP> was accomplished with a limit of detection of 0.027nM. Considering the simplified optical instrumentation required for retroreflection-based RJP counting, RJP-assisted Hg<SUP>2+</SUP> measurement can be accomplished in a much easier and inexpensive manner. Moreover, the detection of Hg<SUP>2+</SUP> in real drinking water samples including tap and commercial bottled water was successfully carried out.</P> <P><B>Highlights</B></P> <P> <UL> <LI> Retroreflection-based mercury ion sensing strategy was developed. </LI> <LI> Hg<SUP>2+</SUP>-mediated thymine-thymine (T-T) pairing was employed as Hg<SUP>2+</SUP> sensing principle. </LI> <LI> Retroreflective Janus particle was utilized as an optical signaling probe for Hg<SUP>2+</SUP> detection. </LI> <LI> Retroreflection-based Hg<SUP>2+</SUP> sensing system enables accurate, convenient and cost-effective Hg<SUP>2+</SUP> detection. </LI> <LI> Hg<SUP>2+</SUP> sensor showed linear dynamic range between 0 and 100nM with the detection limit of 0.027nM. </LI> </UL> </P>

나노형상을 가진 표면플라즈몬공명 센서칩의 감도 개선 효과

조용진 ( Yong Jin Cho ),김철진 ( Chul Jin Kim ),김남수 ( Nam Soo Kim ),김종태 ( Chong Tai Kim ),김태은 ( Tae Eun Kim ),김효섭 ( Hyo Sop Kim ),김재호 ( Jae Ho Kim ) 한국산업식품공학회 2010 산업 식품공학 Vol.14 No.1

표면 플라즈몬 공명을 이용한 센서는 굴절계 기기의 일종으로서 높은 감도를 가질 뿐만 아니라 비표지 방식이라는 장점을 가지고 있다. 본 연구에서는 재래식 SPR 칩을 이용하여 시판 술 4종의 알코올 함량을 측정하였다. 또한, 재래식 SPR 칩의 감도를 개선하기 위하여 금 박막 위에 금으로 나노형상을 구축하여 나노형상 SPR 칩을 제조하여 모형 술에 대한 감도 개선 효과를 분석하였다. 재래식 SPR 칩을 이용하여 시판 술의 알코올 함량을 측정하기 위한 검량선을 개발하였을 때 시료를 전처리 하지 않고 그대로 측정하였을 때 가장 좋은 검량선을 얻을 수 있었다. 소주, 청주, 이과두주, 탁주 등 시판 술 4종에 대한 1차 회귀식의 검량식에서 결정계수는 각각 0.992, 0.933, 0.918, 그리고 0.984로 나타났다. 한편, 재래식 SPR 칩의 감도를 개선하기 위해 나노형상 SPR 칩을 제조하기 위하여 Langmuir-Blodgett(LB) 방법을 활용하였다. 본 연구에서는 수십 nm 두께의 금 박막을 바닥층으로 하여 그 위에 나노크기의 실리카 입자를 단분자 층으로 덮어 형틀을 제조하고 다시 그 위에 금을 증착한 후 실리카 입자를 제거하는 방법으로 나노형상을 갖는 SPR 칩을 제조하였다. 나노형상 SPR 칩의 성능을 평가하였을 때 20% 알코올 함량을 가지는 모형 술에 대해서 바닥층의 두께가 50 nm, 나노형상에서 골의 깊이가 20 nm, 나노형상의 배열주기가 300 nm일 때 SPR의 감도가 가장 좋아서 95%의 감도 향상을 얻을 수 있었다. SPR의 감도는 칩과 관련된 인자, 시료의 종류 및 상태에 따라 다르게 나타날 수 있으므로 측정 목적에 알맞은 칩의 설계와 선택이 요구된다. Surface plasmon resonance (SPR) which is utilized in thin film refractometry-based sensors has been concerned on measurement of physical, chemical and biological quantities because of its high sensitivity and label-free feature. In this paper, an application of SPR to detection of alcohol content in wine and liquor was investigated. The result showed that SPR sensor had high potential to evaluate alcohol content. Nevertheless, food industry may need SPR sensor with higher sensitivity. Herein, we introduced a nano-technique into fabrication of SPR chip to enhance SPR sensitivity. Using Langmuir-Blodgett (LB) method, gold film with nano-structured surface was devised. In order to make a new SPR chip, firstly, a single layer of nano-scaled silica particles adhered to plain surface of gold film. Thereafter, gold was deposited on the template by an e-beam evaporator. Finally, the nano-structured surface with basin-like shape was obtained after removing the silica particles by sonication. In this study, two types of silica particles, or 130 nm and 300 nm, were used as template beads and sensitivity of the new SPR chip was tested with ethanol solution, respectively. Applying the new developed SPR sensor to a model food of alcoholic beverage, the sensitivity showed improvement of 95% over the conventional one.

다중벽 탄소나노튜브를 함유한 PC/ABS 복합재의 마모 특성 및 다중벽 탄소나노튜브의 유출 평가

이현우(Hyun-Woo Lee),김경식(Kyung-Shik Kim),이재혁(Jae-Hyeok Lee),김효섭(Hyo-Sop Kim),김재호(Jae-Ho Kim),오동훈(Dong-Hoon Oh),류상효(Sang-Hyo Ryu),장영찬(Young-Chan Jang),김재현(Jae-Hyun Kim),이학주(Hak-Joo Lee),김광섭(Kwang-Seop Kim 한국트라이볼로지학회 2014 한국윤활학회지(윤활학회지) Vol.30 No.5

Carbon nanotubes (CNTs) are used in various composite materials to enhance electrical, thermal and mechanical properties of composite materials. In this study, we investigate the wear characteristics of polycarbonate/acrylonitrile-butadiene-styrene (PC/ABS) blends containing multi-walled carbon nanotubes (MWCNTs). PC/ABS blends are commonly used in many industrial applications such as cellular phones and display cases and MWCNTs have been added to the PC/ABS blends to improve their electromagnetic interference shielding (EMS). We performed wear tests on PC/ABS blends containing MWCNTs under reciprocating linear sliding conditions with chrome steel balls as a counterpart material. The normal loads were 10, 30, 50, 70, 100 N, the sliding speed was 10 mm/s, the stroke length was 15 mm, and the tests lasted 900 s. The MWCNTs included in the PC/ABS blends lower the wear volume and friction coefficient of the composites. We analyzed the wear debris collected from the composites during the tests in terms of the MWCNT concentration using inductively coupled plasma optical emission spectroscopy. The results show that the quantity of MWCNTs in the debris is proportional to the concentration of MWCNTs in the composite, indicating that the exposure of the MWCNTs to environments by wear could be increased with their concentration in the composite.

해상화물운송장 사용의 활성화에 관한 연구

김효진,박명섭 한국해운학회 2000 해운물류연구 Vol.30 No.-

The purpose of this paper is to study Sea Waybill, the new transport document replacing the traditional Bill of Lading in international trade. In a word, Sea Waybill is thought a type of shipping document by revolution of transport and communication. The high speed of ship and delay of document delivery resulted Sea Waybill. In 1970, the use of Sea Waybill was increased step by step. Sea Waybill was used at first in Europe. In North Atlantic line and Europe line, the Sea Waybill use was 80% in 1996. However. Sea Waybill use of east Asian Line including Korea is sluggish at about 15%. The paper is composed of 6 chapters. Chapter I introduces the purpose and scope of the research. Chapter II reviews a general outline of Sea Waybill including its characteristics. Chapter III compares Sea Waybill and other transport documents. Chapter IV discusses the problems in using sea waybill and methods of overcoming the demerits of Sea Waybill. Chapter V tackles proper measures to solve the problems in using sea waybill. Chapter VI, as the conclusion, suggests several proposals for proper use of the new transport document in international trade.

Cloning and Molecular Characteristics of an apr Gene of Bacillus subtilis NS15-4 Encoding an Alkaline Protease

Hyo-Young Jeong,Jong Hwa Kim,Hee-Sop Nam,Hyung-Jae Lee,Tae Kwang Oh,Moon-Sik Yang,Keon-Sang Chae 한국식품과학회 1997 Food Science and Biotechnology Vol.6 No.3

1 차원 공간 부호화 방법을 이용한 광논리 구현

김종윤,박세준,권효섭,서동환,조웅호,김수중 경북대학교 전자기술연구소 2000 電子技術硏究誌 Vol.21 No.1

In this paper, it is proposed a modified optical shadow-casting system using one-dirrensional spatial encoding method. The proposed system, which is compared with a traditional optical shadow-casting system using geometrical optics, can reduce the spatial size by using a collimated light and aligning input patterns with decoding mask. These inert patterns and decoding masks are placed at a short distance regardless of a spatial distance between them.

Articles : Life Science ; Potential roles of GABA receptors in morphine self-administration in rats

( Seong Shoon Yoon ),( Bong Hyo Lee ),( Hey Soo Kim ),( Ki Hwan Choi ),( Jae Suk Yun ),( Eun Young Jang ),( In Sop Shim ),( Jung Ae Kim ),( Mi Ryeo Kim ),( Chae Ha Yang ) 영남대학교 약품개발연구소 2008 영남대학교 약품개발연구소 연구업적집 Vol.18 No.-

Modulation of semiconducting behavior in carbon nanotube Langmuir-Blodgett film based devices by controlling the effective channel dimension

Nam, Gwang-Hyeon,Kim, Ki-Suk,Park, Sun-Hyun,Kim, Hyo-Sop,Ahn, Dae-Hee,Kim, Jae-Ho,Lee, Jae-Hyeok Elsevier 2019 APPLIED SURFACE SCIENCE - Vol.481 No.-

<P><B>Abstract</B></P> <P>Controlling the electrical property of single-walled carbon nanotube (SWCNT)-based devices is challenging because the SWCNTs have semiconducting or metallic characteristics that are dependent on their chirality. In this report, we demonstrate that a monolayer SWCNT bundle Langmuir-Blodgett (LB) film exhibits anisotropic electrical properties owing to the aligned assembly, and therefore the devices fabricated from this film demonstrate different gating effects reliant on the channel dimensions. Control of the channel dimension significantly affects the modulation of semiconducting behavior of the SWCNT-based devices. The shrinkage of the channel dimension induces a drastic decrease in the metallic pathway, which in turn enhances the semiconducting behavior of the device.</P> <P><B>Highlights</B></P> <P> <UL> <LI> Well aligned SWCNT film-based devices were prepared by Langmuir-Blodgett (LB) technique. </LI> <LI> Channel dimension of SWCNT LB film affects the semiconducting property of the devices. </LI> <LI> The shrinkage of the channel dimension enhances the semiconducting behavior of the device. </LI> </UL> </P>