• Title/Summary/Keyword: 금 나노입자

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Application of AuNPs immobilized on UV Cross-linked P4VP Thin Film as pH Nanosensors (pH 나노센서로의 응용을 위한 UV-가교 P4VP 박막에 고정한 금 나노입자의 특성)

  • Kim, Min-Sung;Jeong, Yeon-Tae
    • Journal of the Korean Institute of Electrical and Electronic Material Engineers
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    • v.21 no.11
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    • pp.1010-1018
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    • 2008
  • In this report, we describe the use of gold nanoparticles (AuNPs) immobilized on pH. responsive, cross-linked poly(4-vinylpyridine) (P4VP) thin films, as a potential application for pH nanosensors. The methodology is based on the variation in surface plasmon resonance of immobilized AuNPs with changing the interparticle distances, caused by the swelling/deswelling of the pH responsive P4VP polymer films. The change in optical properties of the immobilized AuNPs in response to the pH of surrounding media was investigated by a simple yet powerful tool; UV-vis absorption spectroscopy. The swelling of the P4VP chains at pH 2 causes an increase in the interparticle distances of immobilized AUNPS ($\sim20nm$) and hence leads to a blue shift of 48 nm in their surface plasmon resonance band peak. On the other hand, when the surrounding media was altered from pH 2 to 10, a red shift of absorption maxima was observed. The changes were rapid, and the effect was reversible. This system could prove to be useful in fabricating nanosensors for detecting the pH or pH changes of surrounding aqueous medium.

Synthesis of Colloidal Gold and Application of Skin Care Cosmetics (콜로이달 골드 합성 및 스킨케어 화장품 응용)

  • Kim, Dae-Seop;Jeong, Seung-Hyun;Kim, In-Young
    • Journal of the Korean Applied Science and Technology
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    • v.38 no.5
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    • pp.1325-1334
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    • 2021
  • This study reports the development of a manufacturing method of synthesizing colloidal gold using catalysts available for cosmetics and an anti-aging ampoule with skin improvement effects using it. Nano-colloidal gold was synthesized by using ascorbic acid and sodium borohydride as a reducing catalyst in hydrogen tetrachloroaurate tetrahydrate. It was confirmed that the particles became smaller as the mass of the content of ascorbic acid, which is a catalyst, increased. On the other hand, as the mass of sodium borohydride increased, the particle size tended to increase. In order to control the colloidal gold reaction rate, particles having 100 to 500 nm of a particle diameter distribution could be obtained using xanthan gum and hydroxyethylcellulose. The optimal synthesis conditions could be obtained by reacting for 1 to 4 hours at 18℃, a reduced pressure state of 20 to 75 mmHg, a stirring speed of 10~50 rpm. The synthesized colloidal gold had a unique smell of dark pink, pH = 5.5, specific gravity of 1.0032, and viscosity of 80 to 310 cps. As an application of skin care cosmetics, anti-aging ampoule has been developed, and it is expected to be used for various prescriptions and formulations using it.

Flux pinning properties of Y-Ba-Cu-O thin films grown on STO substrates with assembled Au nanoparticles (금 나노입자가 배열된 STO기판에서 성장된 Y-Ba-Cu-O박막의 Flux pinning 특성)

  • Oh, Se-Kweon;Jang, Gun-Eik;Lee, Cho-Yeon;Hyun, Ok-Bae
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 2009.06a
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    • pp.375-375
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    • 2009
  • For many large-scale applications of high-temperature superconducting materials, large critical current density($J_c$) in high applied magnetic fields are required. A number of methods have been reported to introduce artificial pinning centers(APCs) in $YBa_2Cu_3O_{7-\delta}$(YBCO) films for enhancement of their $J_c$. We report measurements of critical current in $YBa_2Cu_3O_{7-\delta}$ films deposited by PLD on $SrTiO_3$ substrates decorated with Au nanoparticles. Au nanoparticles were synthesized on STO substrates with self assembled monolayer. Microstructural analysis of the obtained YBCO films was performed by using cross-section transmission electron microscopy(TEM). Phase and textural analysis was done using X-ray diffraction. The surface morphology and surface roughness(Ra) of the layers was measured by atomic force microscopy(AFM).

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Effects of Light Incident Mode on Optical Scattering of Au Nanoparticle by Localized Surface Plasmon Resonance (빔의 입사모드가 금 나노입자의 국소표면플라즈몬 산란광에 미치는 영향)

  • Lee, Taek-Sung;Lee, Kyeong-Seok;Kim, Won-Mok;Lee, Jang-Kyo;Byun, Seok-Joo
    • Journal of the Korean Institute of Electrical and Electronic Material Engineers
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    • v.22 no.4
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    • pp.307-313
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    • 2009
  • Quantitative analysis of optical scattering intensities from a Au nanoparticle with a diameter of 100 nm, which is effected by the localized surface plasmon resonance (LSPR), were numerically carried out by using a dark-field detection scheme on prism basal plane for two different beam incident modes of reflectance (R-mode) and transmittance (T-mode). Two-dimensional finite difference time domain (FDTD) algorithm was adopted, and its applicabilibility was verified by comparing the simulation results with the theoretical ones. Simulation results of the scattered light intensities from a Au nanoparticle revealed that the scattered intensity of the T-mode was much stronger than that of R-mode. Comparison of the calculated results with the theoretical intensity distribution on the prism showed that the scattered intensity is marimized when the evanescent field, which is generated from the interface of prism and air at TIR angle, is coupled with Au nanoparticle.

Fabrication of hyaluronic acid membrane using electrospinning method and its application as a catalyst support for gold nanoparticles (전기방사를 이용한 히알루론산 멤브레인의 제조 및 금 나노입자 촉매 담체로의 응용)

  • Lee, Namhun;Park, Hyun-Min;Lee, Sang-Myung;Lee, Dae-Won
    • Journal of Industrial Technology
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    • v.38 no.1
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    • pp.15-19
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    • 2018
  • In this study, hyaluronic acid (HA) was electro-spun to fabricate nanofibrous membranes for support materials. Because HA is very hygroscopic, it is difficult to obtain enough viscosity to apply electrospinning method. Therefore, we mixed HA with polyethylene oxide (PEO) to obtain proper viscosity and added adipic acid (ADH) to promote cross-linking of PEO/HA during electrospinning. The morphology of PEO/HA membrane was optimized according to PEO/HA concentration ratio and spinning rate. Finally, we fabricated gold-nanoparticle-embedded PEO/HA membranes and their catalyst activities were evaluated in tetramethylbenzidine (TMB) oxidation.

Antiangiogenic Effects of Gold Nanoparticles VEGF-induced Vascular Endothelial Cells (금 나노입자의 VEGF에 의해 유발된 혈관 내피세포의 신생혈관형성 억제 효과)

  • Choi, Seung-Hyun;Ryu, Geun-Chang;Kim, In-Suk;Chae, Soo-Chul
    • Korean Journal of Environmental Biology
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    • v.28 no.1
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    • pp.14-19
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    • 2010
  • Angiogenesis is an important event involved in cell growth and wound healing process. However, the imbalance of growth factors causes diseases, such as ocular, inflammatory diseases. One of treatment of these diseases is to suppress the formation of blood vessels. Function and mechanism of gold nanoparticles (AuNPs) in the formation of blood vessels is not yet proved. Pigment epithelium derived factor (PEDF) is currently being offered anti-angiogenic materials. In this study, we postulated that AuNPs might have the ability to inhibit angiogenesis, the pivotal step in tumor growth, invasion and metastasis. We have demonstrated that AuNPs could inhibit vascular endothelial growth factor (VEGF) induced cell proliferation, angiogenesis in bovine retinal endothelial cells.

Gold Nanoparticles Inhibit AGEs Induced Migration and Invasion in Bovine Retinal Endothelial Cells (소망막내피세포에서 금 나노입자의 최종당화산물에 의한 세포 이동 및 침윤성 억제 효과)

  • Chae, Soo-Chul
    • Korean Journal of Environmental Biology
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    • v.28 no.1
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    • pp.8-13
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    • 2010
  • This study aimed the role of gold nanoparticles (AuNP) in advanced glycation end-products (AGEs) induced migration and invasion in bovine retinal endothelial cells (BRECs). BRECs were isolated from the retina. Cell viability was confirmed by the MTT assay. In vitro wound migration assay was performed to investigate the migration of BRECs. In vitro tube formation was measured by on-gel system. Apoptosis induced by AuNP was confirmed by caspase-3 assay. AGE-bovine serum albumin (BSA) demonstrated increase of cell migration and proliferation in BRECs. In addition, AuNP regardless of the existence of AGE-BSA suppressed proliferation, migration, and angiogenesis. AuNP suppressed AGE-BSA induced migration and invasion, and induced apoptosis through caspase-3. As a results, AuNP have a potential anti-angiogenic effect for AGE-induced angiogenesis in vitro and offer possibility for the treatment of diabetic retinopathy.

Sintering Characteristics of Au and Ag Nanoparticles Prepared by Inert Gas Condensation (불활성 증발 응축방법으로 제조된 금과 은 나노입자의 소결특성)

  • Lee, Seung-Hyun;Min, Dong-Ryoul;Lee, Kwang-Min
    • Journal of Powder Materials
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    • v.14 no.3 s.62
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    • pp.165-172
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    • 2007
  • The purpose of this study was to analyze the sintering characteristics of gold and silver nanoparticles. In this study, gold and silver nanoparticles were prepared by using Inert Gas Cndensation (IGC). The sintering temperatures for gold and silver nanoparticles were $100{\sim}1000^{\circ}C\;and\'100{\sim}500^{\circ}C$, respectively. The sintering characteristics of gold and silver nanoparticles prepared by IGC were evaluated by X-ray diffraction(XRD), transmission electron microscopy (TEM), and scanning electron microscopy (SEM). Gold and silver nanoparticles with the size of $1{\sim}100\;nm\;and\;10{\sim}100\;nm$, respectively, were obtained. The size of sintered gold and silver nanoparticles increased with an increase in the sintering temperature. XRD data showed that silver nanoparticles were similar with polycrystal single-phase.

Fabrication of Au Nanoparticle for Au-conjugate Immuno Chemistry Probe (Au-conjugate 면역화학 진단용 금 나노입자 제조)

  • Park, Sung-Tae;Lee, Kwang-Min
    • Korean Journal of Materials Research
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    • v.13 no.8
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    • pp.550-554
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    • 2003
  • Current nanogold cluster synthesized by chemical routine with 11 or 55 atoms of gold has been widely used for immuno chemistry probe as a form of nanocluster conjugated with biomolecules. It would be an undeveloped region that the 1 nm size of nanogold could be made by materials engineering processing. Therefore, objective of this study is to minimize the size of gold nanocluster as a function of operating temperature and chamber pressure in inert gas condensation (IGC) processing. Evaporation temperature was controlled by input current from 50 A to 65 A. Chamber pressure was controlled by argon gas with a range of 0.05 to 2 torr. The gold nanocluster by IGC was evaluated by X-ray diffraction (XRD) and transmission electron microscopy (TEM). The gold nanocluster for TEM analysis was directly sampled with special in-situ method during the processing. Atomic force microscopy (AFM) was used to observe 3-D nanogold layer surfaces on a slide glass for the following biomolecule conjugation step. The size of gold nanoclusters had a close relationship with the processing condition such as evaporation temperature and chamber pressure. The approximately 1 nm size of nanogold was obtained at the processing condition for 1 torr at $1124 ^{\circ}C$.

Novel Detection Technology for Glycated Hemoglobin using Gold Nanoparticles (금 나노입자를 이용한 새로운 당화혈색소의 검출 기술)

  • Lee, Soo Suk
    • Journal of Sensor Science and Technology
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    • v.25 no.6
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    • pp.435-439
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    • 2016
  • We report a novel detection technology for glycated hemoglobin (HbA1c) that is measured primarily to identify the three-month average plasma glucose concentration. In enzymatic measuring of glycated hemoglobin, the generated hydrogen peroxide was then used as a reducing agent of gold (III) for the synthesis of gold (0). Gold nanoparticles obtained from this novel approach were measured by optical and piezoelectric methods. In optical method, we have developed polymer based film-type sensor cartridge filled with all the reagents for glycated hemoglobin analysis and the cartridge worked very well having the detection limit of 0.53% of glycated hemoglobin. On the other hand, quartz crystal microbalance (QCM) sensors also have been developed to determine the abilities of surface modified QCM sensors at various levels of the concentration of glycated hemoglobin to bind gold nanoparticles and limit of detection was 0.90%. Finally, despite of relatively lower sensitivities of QCM sensor and film-type optical sensor than well-plate based optical detection, these two sensors were available to measure the glycated hemoglobin level for diabetes patients and normal person.