• 한국전기전자재료학회:학술대회논문집
• /
• 한국전기전자재료학회 2009년도 하계학술대회 논문집
• /
• pp.49-49
• /
• 2009

Nanocomposites of gold nanoparticles and multi-walled carbon nanotubes (MWNTs) were prepared by electrostatic interaction. Gold nanopartic1es were stabilized by polyvinylpyrrolidone (PVP), sodium dodecyl sulfate (SDS) and poly(sodium-4-styrenesulfonate) (PSS) in aqueous medium, and MWNTs were modified by poly(diallyldimethylammonium)chloride (PDDA) in water. The as-perpared Au-MWNT nanocomposites were structurally and electrically characterized by transmission electron microscopy (TEM), field emission scanning electron microscopy (FE-SEM), X-ray diffraction (XRD), UV/Vis spectroscopy, X-ray photoelectron spectroscopy (XPS) and cyclo voltammetry (CV). UV/Vis spectra of Au-MWNT nanocomposites showed the characteristic surface plasmon bands in the range of ~515nm, depending on the stabilizers. There is only slight change on the band shape with variation of stabilizing agents for gold nanoparticles. Through FE-SEM and TEM images, the distribution of gold, nanoparticles on the sidewalls of MWNTs was deliberately investigated on Au-MWNT nanocomposites treated with different stabilizers. XPS and CV showed redistribution of electron densities and changes in the binding energy states of nanopartic1es in nanocomposite respectively.

• Bulletin of the Korean Chemical Society
• /
• 제33권1호
• /
• pp.100-104
• /
• 2012

Thrombin is a serine protease that catalyzes the conversion of soluble fibrinogen to insoluble fibrin, and thus induces physiological and pathological blood coagulation. Therefore, it is important to detect thrombin in blood serum for purposes of diagnosis. To achieve this goal, it has been suggested that a 15-mer aptamer strongly binds with thrombin to form a G-quartet structure of the aptamer. Generally, 5'-end thiol-functionalized aptamer has been used as an anti-thrombin binder. Herein, we evaluate the possibility of utilizing a 3'-SH aptasensor for thrombin detection using SPR spectroscopy, and compare the enhancement of the electrochemical signal of the thrombin-aptamer bound on a porous gold substrate. Although the two aptamers have similar configurations, in SPR analysis, the 3'-SH aptamer was a effective aptasensor as well as 5'-SH aptamer. Results from electrochemical analysis showed that the porous gold substrate acted as a good substrate for an aptasensor and demonstrated 5-fold enhancement of current change, as compared to gold thin film.

• 한국광학회:학술대회논문집
• /
• 한국광학회 2006년도 동계학술발표회 논문집
• /
• pp.93-94
• /
• 2006

• 전기화학회지
• /
• 제3권1호
• /
• pp.49-56
• /
• 2000

정상상태 회전원판전극(RDE)방법과 유체역학적 요동에 의한 전기화학적(EHD) 임피던스방법을 이용하여 금(Au)회전 원판전극(rotating disk electrode)표면에 형성된 PVC(polyvinyl chloride)피막내 산소확산계수의 온도의존성에 대한 연구를 수행하였다. PVC 피막내에서의 산소확산속도(산소확산계수와 피막두께의 비) $D_f/\delta_f$는 한계전류 대 전극회전각속도의 변화로부터 측정하였고, 확산시간상수(diffusion time constant) $\delta_f^2/D_f$측정된 임피던스 값을 $\ulcorner$비전도성, 다공성 피막을 통한 물질이동$\lrcorner$에 대한 확산방정식으로부터 계산된 값에 피팅(fitting)하여 얻었다. 이 측정된 확산속도와 확산시간상수로부터 상온에서 PVC피막의 두께 $\delta_f$와 피막내에서의 산소확산계수(diffusivity) $D_f$를 각각 결정하였다. 온도가 증가함에 따라 측정된 PVC내에서의 산소확산계수가 용액에서의 산소확산계수 $D_s$보다 더 빠르게 증가하였다. 이는 온도가 증가함에 따라 PVC피막내 공공이 성장하고, 이 공공들이 피막내에서 유효한 확산경로로 작용한다는 것을 의미한다. 본 정상상태 및 유체역학적 요동상태 실험방법을 이용하여 금속표면에 존재하는 비전도성 다공질피막의 두께와 피막내 산소확산계수를 동시에 측정할 수 있었으며, 피막의 다공도를 정량적으로 계산할 수 있었다.

• 한국기계가공학회지
• /
• 제15권6호
• /
• pp.95-100
• /
• 2016

We suggest and simulate an optical filter that a red wavelength range cannot transmit to protect the psychological stress that originates from the cognition of red color in emergency medical technicians. When a nanohole hexagonal array is fabricated on gold film using Anodic Aluminum Oxide (AAO), the blocked wavelength can be tuned by the hole diameter and film thickness. The characteristic of the transmittance for normal incident white light is simulated with Finite Element Method (FEM) in the MATLAB platform. Although the transmittance of the overall wavelength is reduced by 50% by the gold film, the transmittance of the red wavelength range is decreased by over 87%.

• 접착 및 계면
• /
• 제11권4호
• /
• pp.144-148
• /
• 2010

본 연구에서는 플라즈몬 공명 신호 증폭을 위한 AuNPs의 실리카 표면 개질 및 나노 입자의 안정적인 표면 박막 형성을 목표로 하였다. 직경 10 nm의 AuNPs를 수용액 상에서 제조하였으며, AuNPs 표면에 실리카 층을 단계별로 형성시켰다. Tetraethlyorthosilicate 농도를 조절함으로써 실리카 박막 두께를 조절하였으며, 얻어진 나노 입자들을 수용액 표면에 분산시켜 Langmuir-Blodgett 박막을 제조하였다. 흡광스펙트럼의 변화를 관찰함으로써 AuNPs의 크기 변화를 확인하였으며, 원자 힘 현미경으로 LB 박막의 형성 여부와 표면 균일도를 살펴보았다.

• 센서학회지
• /
• 제7권4호
• /
• pp.279-284
• /
• 1998

수용액에서 자당의 농도 변화를 감지하기 위한 센서개발을 목적으로 하여, 금박막을 센서칩으로 사용한 SPR(surface plasmon resonance) 센서시스템을 구성하였다. 센서칩 제작시 금박막의 특성조건은 SPR 현상에 매우 큰 영향을 미치므로, 센서 제작의 최적화를 위해 특성을 분석하여 두께 약 $545\;{\AA}$, 표면 평균 거칠기 약 $3\;{\AA}$이 되도록 균일하게 제작하였다. 이렇게 제작된 금박막 센서칩의 공명각은 $43.75^{\circ}$ 이었으며, $0{\sim}40\;wt%$ 농도의 자당 수용액을 측정한 결과 기존의 알려진 자당 센서에 비해 빠른 응답특성과 선형적인 공명특성을 얻을 수 있었다.

• 한국진공학회:학술대회논문집
• /
• 한국진공학회 2016년도 제50회 동계 정기학술대회 초록집
• /
• pp.354.1-354.1
• /
• 2016

Nanoporous gold (NPG) is a very promising material in various fields such as sensor, actuator, and catalysis because of its high surface to volume ratio and conducting nature. In this study, we fabricated a NPG based amperometric sensor on a glass substrate by means of co-sputtering of Au and Si. During the sputtering process, we found the optimum conditions for heat treatment to reduce the residual stress and to improve adhesion between NPG films and the glass substrate. Subsequently, Si was selectively etched from Au-Si alloy by KOH solution, which forms nanoporous structures. Scanning electron microscopy (SEM) and auger electron spectroscopy (AES) were used to estimate the structure of NPG films and their composition. By employing appropriate heat treatments, we could make very stable NPG films. We tested the performance of NPG sensor with aniline molecules, which shows high sensitivity for sensing low concentration of aniline.

• 전기학회논문지
• /
• 제56권7호
• /
• pp.1294-1297
• /
• 2007

In this paper, fabrication techniques for nanoscale metallic nanobeam specimens have been proposed, and mechanical properties of the fabricated gold nanobeams have been evaluated by nanoindentation techniques and nanobeam bending test. Elastic modulus and hardness of gold nanobeams were measured to be $109.6\;{\pm}\;10\;GPa\;and\;1.73\;{\pm}\;0.3\;GPa$, respectively, from the nanoindentation test, while elastic modulus was $241\;{\pm}\;7\;GPa$ from the nanobeam bending test.

• 보존과학연구
• /
• 통권14호
• /
• pp.45-76
• /
• 1993

Au-Cu alloyed coating layer were found by Hg-amalgam process and it seemed to be used Cu-amalgam process similar to Au-amalgam. Coated layer is dense and unique, Thickness of layer was 1.5 to $18.0\mum$ which had 95.3 to 99.8% purity of gold Matrix metal mostly cosists of forged copper alloy which had high purity and ferrite ($\alpha$) strusture. It showed excellent refining technical level at that time. Aowever, the nail, ferrous matrix used for strength needed, composed of silver foil packed and gold layer for adherence between ferrous matrix and gold layer