• Bulletin of the Korean Chemical Society
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• 제33권11호
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• pp.3735-3739
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• 2012

We have developed magnetically controllable gold nanoparticles by synthesizing superparamagnetic $Fe_3O_4$ core/gold shell nanoparticles. The core/shell particles have the capability of forming gold 1D chains in the presence of an external magnetic field. Here we demonstrate dynamic and reversible self-assembly of the gold 1D chain structures in an aqueous solution without any templates or physical or chemical attachment. The spatial configuration of gold chains can be arbitrarily manipulated by controlling the direction of a magnetic field. This technique can provide arbitrary manipulation of gold 1D chains for fabrication purpose. To demonstrate this capability, we present a technique for immobilization of the gold particle chains on a glass substrate.

• ALGAE
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• 제18권2호
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• pp.121-127
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• 2003

The pyrenoid ultrastructure and distribution of ribulose-1,5-bisphosphate carboxylase/oxygenase (Rubisco) and Rubisco activase in the chloroplasts of Chlamydomonas reinhardtii was studied using the immunogold localization technology with electron microscopy. There were several tubular thylakoids invading in the pyrenoid matrix to form several spokewise channels. The connections between pyrenoid matrix and stroma of chloroplast were the partial of channels. The starch sheath surrounding the pyrenoid was separated into several parts by the connections in transection. Some thylakoids were packed together near the connections in one side of the pyrenoid. Those special structures might be used to transport substance between pyrenoid and stroma of chloroplasts. With the antibody raised against the large subunits of Rubsico from C. protothecoides, the result of the gold immunolocalization of Rubisco in Chlamydomonas reinhardtii showed most of the gold particles heavily labeled the pyrenoid matrix, as well as the starch sheath matrix, and very few in the stroma of chloroplasts. The gold particle density was 880.00 $\pm$ 164.32, 190.00 $\pm$ 152.39 and 9.60 $\pm$ 5.37 ${\mu}m^{-2}$ in pyrenoid matrix, starch sheath and stroma region of chloroplast respectively (background: 5.67 $\pm$ 1.53 ${\mu}m^{-2}$). 99.59% of the total Rubiscos was calculated to be concentrated in the pyrenoid matrix and starch sheath by spatial densities. The gold immunolocalization of Rubisco activase also showed that Rubisco activase was mainly concentrated in the periphery of the pyrenoid and the starch sheath (the density was as high as 229.69 $\pm$ 96.96 ${\mu}m^{-2}$). There were very few gold particles located in the stroma of chloroplasts. These results indicated that pyrenoid surface and starch sheath was the site for Rubisco activation and $CO_2$ fixation, which supported the suggestion that pyrenoids perform photosynthesis function.

• Macromolecular Research
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• 제16권2호
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• pp.163-168
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• 2008

Polystyrene/gold nanoparticle (PS/AuNP) composite fibers were fabricated using an electrospinning technique. Transmission electron microscopy (TEM) showed that the diameters of the naphthalenethiol-capped gold nanoparticles (prior to incorporation into the PS fibers) ranged from 2 to 5 nm. UV-vis spectroscopy revealed the surface plasmon peaks of the gold nanoparticles centered at approximately 512 nm, indicating that nano-sized Au particles are well-dispersed in solution. This was consistent with the TEM observations. The electrospun nanofibers of PS/AuNP composites were approximately 60-3,000 nm in diameter. The surface morphology of the PS/AuNP composite and the dispersability of the Au nanoparticles inside of PS after electrospinning process were investigated by SEM and TEM. The thermal behavior of the pure PS and PS/AuNP nanocomposites and fibers were examined by DSC.

• Bulletin of the Korean Chemical Society
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• 제31권5호
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• pp.1177-1181
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• 2010

The synthesis and characterization of gold nanoparticles coated by Gd-chelate (GdL@Au) is described, where L is a conjugate of DTPA (DTPA = diethylenetriamine-N,N,N',N",N"-pentaacetic acid) and 4-aminothiophenol. These particles are obtained by the replacement of citrate from the gold nanoparticle surfaces with gadolinium chelate (GdL). The average size of GdL@Au is 12 nm with a loading of GdL reaching up to $1.4{\times}10^3$ per particles, and they demonstrate very high r1 relaxivity (${\sim}10^4mM^{-1}s^{-1}$) and the r1 relaxivity per [Gd] is as high as $10mM^{-1}s{-1}$. Here, we also describe the use of bimodality of this contrast agent (CA) as a highly efficient CT contrast agent based on gold nanoparticles (GNPs) that overcome the limitations of iodine based contrast agent. The MTT assay performed on this CAs reveals the cytotoxicity as low as that for Omniscan$^{(R)}$ in the concentration range required to obtain intensity enhancement in the in vivo MRI study.

• 대한기계학회논문집A
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• 제28권7호
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• pp.999-1005
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• 2004

A new stamp fabrication technique for the soft lithography has been developed in the range of several microns by means of a nano-replication printing (nRP) process. In the nRP process, a figure or a pattern can be replicated directly from a two-tone bitmap figure with nano-scale details. A photopolymerizable resin was polymerized by the two-photon absorption which was induced by a femtosecond laser. After the polymerization of master patterns, a gold metal layer (about 30 ㎚ thickness) was deposited on the fabricated master patterns for the purpose of preventing a join between the patterns and the PDMS, then the master patterns were transferred in order to fabricate a stamp by using the PDMS (poly-dimethylsiloxane). In the transferring process, a few of gold particles, which were isolated from the master patterns, remained on the PDMS stamp. A gold selective etchant, the potassium iodine (KI) was employed to remove the needless gold particles without any damage to the PDMS stamp. Through this work, the effectiveness of the nRP process with the PDMS molding was evaluated to make the PDMS stamp with the resolution of around 200 ㎚.

• 대한수의학회지
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• 제29권4호
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• pp.541-548
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• 1989

오제스키병 바이러스를 배양세포에다 감염시켜, 냉동 및 araldite포매 초박절편에서 protein A-gold labeling을 통해 바이러스항원 검출을 시도하였다. 오제스키병 바이러스항원은 10nm gold probes로 표지되었으며, 전자밀도가 높은 gold 입자들은 바이러스의 nucleocapsid와 envelope에서 주로 관찰되었고, 초냉동박절표본에서의 immunogold labeling은 조직구조물들과 극히 미미한 비특이결합만을 보였다. 초냉동박절표본에서의 immunogold labeling은 오제스키병 바이러스항원을 검출하는데 있어 효과적이었으며, 이는 또한 여러가지 바이러스들과 속주세포들간의 상호작용에 관한 면역세포화학적 연구에 크게 이용될 수 있을 것으로 생각된다.

• 대한수의학회지
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• 제33권4호
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• pp.573-577
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• 1993

청설모(Sciurus vulgaris corea)의 췌장에 분포하는 glucagon 및 somatostatin 세포의 분포와 그들 분비과립의 특징을 밝히기 위해 면역조직화학적 및 면역전자현미경적 방법으로 관찰하였다. Glucagon 면역반응세포는 주로 췌도의 주변부에 분포하였고, 때로는 외분비부에서 관찰되었다. 이 세포의 분비과립은 직경이 240~320nm였으며, 전자밀도가 높은 core를 전자밀도가 낮은 halo가 둘러싸고 특히 gold particle들은 전자밀도가 높은 core에 강한 반응을 보였다. Somatostatin면역반응세포는 췌도의 주변부를 따를 면역반응이 아주 약한 세포들로 산재하였으며 또한 외분비에서 단독 혹은 소집단으로 관찰되었다. 이 세포의 분비과립은 전자밀도가 낮고 직경이 250~275nm였으며, gold particle는 분비과립에 중등도로 고른 반응을 보였다.

• Applied Microscopy
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• 제27권4호
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• pp.403-416
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• 1997

In order to observe the localization of the specific antigenic protein in the tissue of Paragonimus westermani metacercaria, immunogoldlabeling method was applied using IgG of the dog which were infected with Paragonimus westermani metacercaria and IgG of rabbits which were immunized with purified 23 kDa protein from metacercaria of the Paragenimus westermani. The metacercaria worm tissues obtained from Cambaroides similis were embedded in Lowicryl HM20 medium, treated with infected and immunized IgG and protein A gold complex (particle size; 12 nm) and observed by electron microscope. In the tissue antigen of Paragonimus westermani metacercaria, the content of excretory bladder which was highly dense electron density was constituted in the excretory bladder of the parenchymal tissue. In the metacercaria tissues antigen reacted with IgG of infected dog. Labeled gold particles distributed on the interstitial matrix of parenchymal cells, fibrous granules of parenchymal tissue and the content of excretory bladder. High antigenicity was observed on content of excretory bladder. It was found to be specifically distributed at the tissue of Paragonimus westermani metacercaria. In the tissues antigen reacted with IgG of immunized rabbit. Labeled gold particles randomly distributed on the interstitial matrix and fibrous granules of parenchymal tissue but in the content of excretory bladder of Paragonimus westermani metacercaria, gold particles were richly labeled. Therefore, the 23 kDa protein contained with Paragonimus westermani metacercaria was found protein which was specifically constituted at the content of excretory bladder of Paragonimum westermani metacercaria. The 23 kDa protein was commonly contained from of Paragonimus westermani metacercaria to adult and showed strong antigenicity against the immunized and infected IgG.

• Bulletin of the Korean Chemical Society
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• 제34권2호
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• pp.363-364
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• 2013

• 한국동물학회지
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• 제35권1호
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• pp.58-69
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• 1992

곤충 혈구의 이물질에 대해 면릉고청을 확인하기 위하여 평균지름 10 nm의 gold입자를 함유한 colloidal gold solution을 등 검은 메뚜기 (Euprepocnemis shirakii Bolivar) 성충의 복강에 주입한 후, 혈구의 반응양상을 전자현미경으로 관찰하였다. Gold 입자에 대한 혈구의 면역반응은 전체 혈구의 약 28%를 차지하고 있는 Plasmatocytes에서 식세포작용(phagocytosis)의 형태로 확인되었고, 다른 종류의 혈구는 반응하지 않았다. Plasmatocytes에 의해 식세포작용의 초기반음은 많은 원형질 돌기를 형성하여 이물질을 포획하는 태면반응과 원형질악의 함입에 의한 식포의 형성과정으로서, 이 과정은 이물질 주입후 10분이내에 완료되는 것으로 관찰되었다. 혈구내에 형성된 식포는 초기에 전자밀도가 낮은, 천상 또는 섬잡상의 내부구조를 가지고 있었으나, 일차 Iysosome의 융합에 의해 전자밀도가 높은 과립상으로 된 후, 결정상의 내부구조로 변형되었으며, 그 이후의 단계에서 multivesicular body형태의 이차 Iysosome을 형성하였다.