• 제목/요약/키워드: Colloidal Au

검색결과 37건 처리시간 0.028초

Nanoscale Floating-Gate Characteristics of Colloidal Au Nanoparticles Electrostatically Assembled on Si Nanowire Split-Gate Transistors

  • Jeon, Hyeong-Seok;Park, Bong-Hyun;Cho, Chi-Won;Lim, Chae-Hyun;Ju, Heong-Kyu;Kim, Hyun-Suk;Kim, Sang-Sig;Lee, Seung-Beck
    • JSTS:Journal of Semiconductor Technology and Science
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    • 제6권2호
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    • pp.101-105
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    • 2006
  • Nanoscale floating-gate characteristic of colloidal Au nanoparticles electrostatically assembled on the oxidized surface of Si nanowires have been investigated. The Si nanowire split-gate transistor structure was fabricated by electron beam lithography and subsequent reactive ion etching. Colloidal Au nanoparticles with ${\sim}5$ nm diameters were selectively deposited onto the Si nanowire surface by 2 min electrophoresis. It was found that electric fields applied to the self-aligned split side gates allowed charge to be transferred on the Au nanoparticles. It was observed that the depletion mode cutoff voltage, induced by the self-aligned side gates, was shifted by more than 1 V after Au nanoparticle electrophoresis. This may be due to the semi-one dimensional nature of the narrow Si nanowire transport channel, having much enhanced sensitivity to charges on the surface.

교질성(膠質性) $^{198}Au$을 사용(使用)한 골수주사(骨髓走査) (Bone Marrow Scans with Colloidal $^{198}Au$)

  • 정성수;황기석
    • 대한핵의학회지
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    • 제7권1호
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    • pp.39-43
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    • 1973
  • The bone marrow scans with colloidal $^{198}Au$ were performed on 33 cases with hematologically normal patients and patients with various blood dyscrasia. Bone marrow aspirations were done at iliac crest in all cases but one. A correlation between the scan findings and an erythroid cellularity was evaluated. The following results were obtained. 1) Out of 33 cases, 23 (about 70%) showed a correlation between $^{198}Au$ marrow uptakes on the scans and the erythroid cellularity. 2) The diseases in which no correlation existed between $^{198}Au$ uptake and erythroid cellularity were aplastic anemia, acute leukemia and chronic myelogenous leukemia.

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광화학적 방법을 이용한 금속입자의 합성과 광학적 특성 연구 (Surface Plasmon Resonances of Metal Colloidal Particles Synthesized by a Photo-Chemical Process)

  • 고민진
    • 대한화학회지
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    • 제43권1호
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    • pp.1-7
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    • 1999
  • 이 논문에서는 광화학적 방법을 이용하여 금속 콜로이드 입자를 반도체 나노입자를 함유한 수용액내에서 제조하여 그 광학적 특성을 관찰하였다. 형성된 금속입자는 사용된 반도체 입자에 따라 다른 경향을 나타낸다. Au 금속 입자를 CdS 입자를 함유한 수용액내에서 제조한 경우 일반적인 금속 입자의 Plasmon Resonance의 특성을 보이는 반면 Ag금속 입자를 AgBr 입자를 함유한 용액내에서 제조한 경우 Red-Shift 현상을 보였고, 그 정도는 UV 조사량에 따라 달라졌다. 이러한 금속 Plasmon Resonance의 Red-Shift 현상을 Effective Medium 이론을 이용하여 이론적으로 설명하였다.

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구리 전착층에 미치는 콜로이달실리카 및 음극 Pre-Coating의 영향 (Effect of Colloidal Silica and Pre-Coating of Cathode on Copper Electrodeposited Film)

  • 이상백;윤정모;박형호;배인성;김병일
    • 한국재료학회지
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    • 제11권7호
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    • pp.569-574
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    • 2001
  • 황산구리 전해욕에 분산제인 콜로이달 실리카($SiO_2$현탁액)를 첨가시키는 분산도금의 방법과 Au pre-coating을 이용하여 음극에 석출하는 전해 석출물의 결정구조, 표면형상, 결정방향 등의 변화를 검토하였다. 실리카 분산 및 Au pre-coating에 의하여 전해 석출피막의 결정입자가 미세화 되고, 균일하게 성장됨은 물론, 결정 수가 증가하였다. 콜로이달 실리카의 분산 효과에 의해서 전해 석출피막의 경도가 대략 15%까지 상승하였다. 또한 콜로이달 실리카를 분산시킨 구리 전착층의 X-선 회절패턴이 (111)면, (200)면과 (311)면이 거의 소멸되어 우선 방위가 (111)에서 (110)면으로 변화되었다.

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교양(膠樣) $^{198}$금(金) 혈액제거율검사(血液除去率檢査)의 간주사판독(肝走査判讀)에의 응용(應用) (An Application of Blood Clearance Rate of Colloidal $^{198}Au$ to the Interpretation of Photoscan of Liver)

  • 박용휘
    • 대한핵의학회:학술대회논문집
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    • 대한핵의학회 1966년도 제5회 학술대회
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    • pp.93.3-94
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    • 1966
  • The fact that colloidal particulates of rdaiogold are mainly and effectively eliminated from the blood stream by phagocytic activity of Kupffer's cells of the liver has been successfully adopted to the diagnosis if certain liver diseases and the same principle has opened a new avenue to the study of the organ by obtaining scan. Indeed, the latter procedure has been widely used for the detection of space-occupying lesions of cirrhosis of the liver. Nevertheless problem of differential diagnosis of monochromatic "cold" areas or "mottling" of the internal structure on the scan limited the value of this diagnostic modality. The present investigation is aimed at improving intepretation of photoscan findings with the aid of blood clearance rate of the intravenously injected colloidal $^{198}Au$.

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Aggregation of Laser-Generated Gold Nanoparticles Mediated by Formalin

  • Alauddin, Md.;Kim, Kuk Ki;Roy, Madhusudan;Song, Jae Kyu;Kim, Myung Soo;Park, Seung Min
    • Bulletin of the Korean Chemical Society
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    • 제34권1호
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    • pp.188-196
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    • 2013
  • We have investigated the effects of formalin on the assembly of colloidal gold nanoparticles (AuNPs) prepared by laser ablation of a solid gold target in deionized water. Upon addition of formalin, the surface plasmon resonance (SPR) band at 519 nm for pure AuNPs decreases and shifts to red while a new broad SPR band appears at ~700 nm. The red-shift is prominent with increase in the incubation time. The average size of the initial AuNPs is around 12 nm but it increases to 23 nm after addition of formalin. It turns out that formalin acts as a cationic surfactant for AuNPs with negative surface charge in the colloidal solutions. Furthermore, through analysis of the Raman spectrum of formalin and the density functional theory calculations, we confirm that methanediol is the main species in formalin which is in charge of the aggregation of AuNPs.

Au 및 $Au/SiO_2$ 나노입자를 이용한 나노부유게이트메모리 단일소자의 전기적 특성 (Electrical Properties of Nano Floating Gate Memory for Using Au and$ Au/SiO_2$ Nanoparticles)

  • 박병준;김현석;조경아;김상식
    • 한국전기전자재료학회:학술대회논문집
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    • 한국전기전자재료학회 2005년도 하계학술대회 논문집 Vol.6
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    • pp.107-108
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    • 2005
  • Au and $Au/SiO_2$ nanoparticles(NPs) were synthesized by the colloidal method. The formation of Au and $Au/SiO_2$ NPs was confirmed using high resolution transmission electron microscopy (HRTEM). Synthesized solutions were deposited on Si wafer. The electrical properties of structures were measured using a semiconductor analyzer and a LCR meter. Capacitance versus voltage hysterisis curves showed the charge storage effect by Au and $Au/SiO_2$ NPs.

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Real-time Monitoring of Colloidal Nanoparticles using Light Sheet Dark-field Microscopy Combined with Microfluidic Concentration Gradient Generator (μFCGG-LSDFM)

  • Choe, Hyeokmin;Nho, Hyun Woo;Park, Jonghoon;Kim, Jin Bae;Yoon, Tae Hyun
    • Bulletin of the Korean Chemical Society
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    • 제35권2호
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    • pp.365-370
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    • 2014
  • For real-time monitoring of colloidal nanoparticles (NPs) in aqueous media, a light sheet type dark-field microscopy system combined with a microfluidic concentration gradient generator (${\mu}FCGG$-LSDFM) was developed. Various concentrations of colloidal Au NPs were simultaneously generated with the iFCGG and characterized with the LSDFM setup. The number concentrations and hydrodynamic size distributions were measured via particle counting and tracking analysis (PCA and PTA, respectively) approaches. For the 30 nm Au NPs used in this study, the lower detection limit of the LSDFM setup was 3.6 ng/mL, which is about 400 times better than that of optical density measurements under the same ${\mu}FCGG$ system. Additionally, the hydrodynamic diameter distribution of Au NPs was estimated as $39.7{\pm}12.2nm$ with the PTA approach, which agrees well with DLS measurement as well as the manufacturer's specification. We propose this ${\mu}FCGG$-LSDFM setup with features of automatic generation of NP concentration gradient and real-time monitoring of their physicochemical characteristics (e.g., number concentration, and hydrodynamic size distribution) as an important component of future high-throughput screening or high-content analysis platforms of nanotoxicity.