• Proceedings of the Korean Vacuum Society Conference
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• 2015.08a
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• pp.231.2-231.2
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• 2015

본 연구에서는 나노갭 소자에 미세유체 수직 이중층을 도입하여 상층에 존재하는 금나노입자를 검출하였다. 형성된 수직 이중 층의 상층에는 검출물질을 주입하였고 하층에는 검출물질과 소자 표면의 전극을 분리 시킬 수 있는 용액을 주입하였다. 수직 이중층의 형성은 크로노암페로메트리(Chronoamperometry)을 이용하여 상층에 흘려준 electrochemical indicator 인 ferricyanide 용액의 전기화학 신호가 발생되지 않음을 통해서 확인하였다. 연속적인 수직 이중 층의 흐름에서 유전영동법을 이용하여 상층에 존재하는 금나노입자들을 나노갭전극으로 유도포획 하였고 이때 실시간으로 변하는 전류 값으로부터 금나노입자의 검출여부를 판단하였다.

• Proceedings of the Korean Vacuum Society Conference
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• 2013.02a
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• pp.447-447
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• 2013

최근 전자산업의 발전으로 차세대 디스플레이 소자로 산화물반도체가 주목받고 있다. 산화물 반도체는 저온공정, 높은 이동도 및 투과율을 가지기 때문에 이러한 공정이나 물성 측면에 있어 기존의 a-Si, LTPS 등을 대채할 만한 소자로서 연구가 활발이 이루어지고 있다. 특히 고해상도 및 고속구동이 진행됨에 따라 높은 이동도의 필요성이 대두되고 있다. 본 연구에서는 IGZO 산화물 반도체 박막트랜지스터의 이동도 개선을 위해 나노입자를 사용하였다. 게이트전극으로 사용된 Heaviliy doped P-type Si 기판위에 200 nm의 SiO2 절연층을 성장시킨 후, 채널로 작동하기 위한 IGZO 박막을 증착하기 전에 10~20 nm 크기의 니켈, 금 나노입자를 부착시켰다. 열처리 온도는 $350^{\circ}C$, 90분동안 진행하였고, 100 nm의 알루미늄 전극을 증착시켜 TFT 소자를 제작하였다. TFT 소자가 동작할 시, IGZO 박막 내부의 전자들은 게이트 전압으로 인해 하부로 이동하여 채널을 형성, 동시에 드레인 전압으로 인한 캐리어들의 움직임으로 인해 소자가 동작하게 된다. 본 연구에서는 채널이 형성되는 계면 부근에 전도성이 높은 금속 나노입자를 부착시켜 다수 캐리어인 전자가 채널을 통과할 때 전류흐름에 금속 나노입자들이 기여하여 전기적 특성의 변화에 어떠한 영향을 주는지 연구하였다. 반응시간을 조절하여 기판에 붙는 나노입자의 밀도 변화에 따른 특성과 다양한 크기(5, 10, 20 nm)를 갖는 금, 니켈 나노입자를 포함한 IGZO TFTs 소자를 제작하여 전달특성, 출력특성의 변화를 비교하였고, 실질적인 채널길이의 감소효율과 캐리어 이동도의 변화를 비교분석 하였다.

• Applied Microscopy
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• v.30 no.4
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• pp.403-412
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• 2000

Urechis unicinctus spermatogenic cells, sperm and spermatids, prepared from testis are investigated to identify nuclear actin using amoeba monorlonal anti-actin as the first Ab and gold particles (10 nm) conjugated mouse IgG (immunogold) as the Ab marker. The Ag-Ab reactions analyzed the localization of nuclear actin of the spermatogenic cells and the immunogold particles incorporated mainly with nuclear matrices. A few immunogold particles are merged into the acrosomes and the other architectures of spermatogenic cells, such as mitochondrion and centrioles. It is often observed and there is a tendency in which the incorporated immunogold particles are increased in number in the nuclear matrices of sperm compared with that of spermatids The increments and decrements of the incorporated immunogold particles according to developmental stages and the spermatogenic architec-tures are interpreted and discussed in aspect of acrosomal function and of nuclear condensation of spermatids.

• Journal of the Korean Chemical Society
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• v.54 no.2
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• pp.228-233
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• 2010

Recently, nanoparticles of gold and silver has been applied to various fields due to antimicrobial property. This study added Ag and Au nanoparticles in HEMA (2-hydroxyethylmethacrylate), NVP (N-vinyl pyrrolidone) and MMA (methylmethacrylate) and copolymerized the solution by heating at $70^{\circ}C$ for 40 minutes, $80^{\circ}C$ for 40 minutes, and finally, $100^{\circ}C$ for 40 minutes. Using the polymer produced through the copolymerization process, and measured the physical characteristics which showed water content of 28.43% ~ 35.27%, refractive index of 1.429 ~ 1.440, visible transmittance of 79.2% ~ 86.5% and tensile strength of 0.125 kgf ~ 0.201 kgf. We judged that we made the copolymer with antimicrobial and physical properties which is suitable for conventional contact lens.

• Proceedings of the Korean Vacuum Society Conference
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• 2010.02a
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• pp.41-41
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• 2010

상온에 준하는 저온의 플라즈마를 발생시키는 장치들이 개발되면서, 저온 플라즈마와 생체조직간의 상호작용에 대한 연구가 큰 관심을 끌고 있다. 플라즈마에서 발생되는 다량의 이온과 활성종, 그리고 UV 등이 박테리아나 세포들과 작용함으로 해서 암세포 사멸, 치아 미백, 박테리아 살균/멸균, 지혈등의 효과들이 나타나고 있으며, 이러한 효과들을 극대화할 수 있는 장치 개발과 플라즈마와 생체조직간의 상호작용 메카니즘을 규명하는 것이 중요한 이슈가 되고 있다. 나노 금입자를 암세포의 막단백질인 FAK의 항체와 결합시킨 중합체를 만들어서, 암세포 표면에 나노 금입자붙이고, 플라즈마를 조사했을 때, 나노 금입자가 부착되지 않았을 경우에 비해서, 5배이상 사멸률이 증가하였다.[1] 변색된 치아에 미백제의 주성분인 과산화수소를 도포하고, 10분간 플라즈마를 조사하게 되면, 과산화수소만 도포했을 때에 비해, 치아 표면의 색이 3배이상 밝아지는 것을 관찰할 수 있었다. 과산화수소를 플라즈마에 노출시켰을 때, 활성종인 OH의 생성이 2배이상 증가하였고, 플라즈마에 의한 OH 생성의 촉진이 치아 미백효과가 증대되는 주된 요인인 것으로 추측된다.[2] 플라즈마에서 발생되는 O, $O_3$와 같은 활성종들은 살균력이 뛰어나기 때문에, 저온 플라즈마를 의료기구의 소독/멸균에 응용할 가능성이 아주 크다. 대장균이나 구강 세균이 플라즈마 처리로 5분이내에 멸균되는 것을 확인하였고, 핸드피스와 같은 의료기구를 오염시켜서 멸균 테스트를 수행하고 있다.

• Journal of the Korea Institute of Military Science and Technology
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• v.12 no.6
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• pp.739-749
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• 2009

Ever since gold was found, this element has fascinated human beings. It is stable in air, and is illuminating for several thousands years without changing its colors. Nanoparticles are the basic nanommaterials, and, particularly gold nanoparticles show unique properties which are not shown in bulk states. Scientists are trying to apply these new properties to catalysts, bioscience, optics, etc. Judging from the current research activities, one can envisage that gold nanoparticles can play a major role in opening a new era in diagnoses and treatment of diseases like cancers. However to apply the nanoparticles one must modify the surface of the nanoparticles in order to give the materials certain functionalities. It certainly is worth to review the current research status and challenges in the area of functional gold nanoparticles.

• Journal of the Korean Society of Radiology
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• v.13 no.2
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• pp.247-252
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• 2019

This study was evaluated absorbed dose according to the gold nanoparticle density in prostate brachytherapy which was constantly occurred in Korean men. Absorbed dose evaluation was using MCNPX program which was applied Monte Carlo simulation. Source were applied $^{192}Ir$ which was temporary insertion source and $^{103}Pd$ which was permanently insertion source. And gold nanoparticle density was applied 0 mg, 7 mg, 18 mg and 30 mg. The prostate absorbed dose was increased in proportion to the density 2.95E-14 Gy/e to 4.42E-14 Gy/e in $^{192}Ir$ and showed the same tendency in $^{103}Pd$. And surrounding organ absorbed dose was inversely proportional to the density. Therefore using nanoparticle in brachytherapy was increased therapeutic ratio.

• Applied Microscopy
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• v.38 no.3
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• pp.235-243
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• 2008

A compact soft x-ray microscope operated in the 'water window' wavelength region ($2.3{\sim}4.4nm$) was used for observing cells with nano-scale spatial resolution. To obtain cellular imaging captured with colloidal gold nanoparticles using a compact soft x-ray microscope. The colloidal gold nanoparticles showed higher contrast and lower transmission more than 7 times than that of cellular protein on the soft x-ray wavelength region. The structure and thickness of the cell membrane of the Coscinodiscus oculoides (diatome) and red blood cells were seen clearly. The gold nanoparticles within the HT1080 and MDA-MB 231 cells were seen clearly on the soft x-ray microscopy. The gold nanoparticles were aggregated within vesicles by endocytosis.

• The Journal of the Acoustical Society of Korea
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• v.35 no.6
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• pp.473-479
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• 2016

We report a highly selective and sensitive 200 MHz Surface Acoustic Wave (SAW) sensor that can detect cyanide ion in aqueous solution using surface immobilized thioester molecules in combination with gold nanoparticles (AuNPs). To construct the sensor device, a monolayer of thioester compound was immobilized on the SAW sensor surface. At the sensor surface, hydrolysis of thioester group by nucleophilic addition of cyanide occurred and the resulting free thiol unit bound to AuNP to form thiol-AuNP conjugate. For the signal enhancement, gold staining signal amplification process was introduced subsequently with gold (III) chloride trihydrate and reducing agent, hydroxylamine hydrochloride. The SAW sensor showed a detection ability of $17.7{\mu}M$ for cyanide in aqueous solution and demonstrated a saturation behavior between the frequency shift and the concentration of cyanide ion. On the other hand, our SAW sensor had no activities for other anions such as fluoride ion, acetate ion and sulfate ion, moreover, no significant interference observed by other anions. Finally, all the experiments were carried out in-house developed sensor and fluidics modules to obtain highly reproducible results.

• Journal of the Korean Chemical Society
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• v.50 no.1
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• pp.32-36
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• 2006

films of gold nanoparticles were formed on indium tin oxide (ITO) by an electrodeposition method from an aminosilicate stabilized gold colloid solution. The thin films were examined by cyclic voltammetry (CV), scanning electron microscopy (SEM), UV-visible, and energy dispersive X-ray spectroscopy (EDXS). The surface coverage of gold nanoparticles on the thin film was estimated to 1.2 nanomole/cm2. An anthraquinone-2, 6-disulfonic acid, disodium salt (AQDS) self-assembled layer was generated by immersing gold thin film into 1mM of AQDS in 0.1M HClO4 solution for over 20 hours. As a result, a new absorbance peak from the multi-layers (AQDS/thin film of gold /ITO) was obtained about at 690 nm. Also, the surface plasmon absorption of multi-layers was measured by UV-Visible spectrometer along with chronoamperometry by applying the various potentials from +0.5V to -0.5V. The maximum surface plasmon absorption band at 550 nm was decreased by applying negative potentials. The change of absorbance was correlated with the surface coverage of the AQDS indicating the pseudo-capacity surface state of the AQDS layer was coupled to the energy level of the plasmonband by applied negative potentials.