http://chineseinput.net/에서 pinyin(병음)방식으로 중국어를 변환할 수 있습니다.
변환된 중국어를 복사하여 사용하시면 됩니다.
Effect of Different Pretreatments on Indium-Tin Oxide Electrodes
최문정,조경민,양해식 대한화학회 2013 Bulletin of the Korean Chemical Society Vol.34 No.2
The effect of pretreatment on indium-tin oxide (ITO) electrodes has been rarely studied, although that on metal and carbon electrodes has been enormously done. The electrochemical and surface properties of ITO electrodes are investigated after 6 different pretreatments. The electrochemical behaviors for oxygen reduction, Ru(NH3)6 3+ reduction, Fe(CN)6 3− reduction, and p-hydroquinone oxidation are compared, and the surface roughness, hydrophilicity, and surface chemical composition are also compared. Oxygen reduction, Fe(CN)6 3− reduction, and p-hydroquinone oxidation are highly affected by the type of the pretreatment, whereas Ru(NH3)6 3+ reduction is almost independent of it. Interestingly, oxygen reduction is significantly suppressed by the treatment in an HCl solution. The changes in surface roughness and composition are not high after each pretreatment, but the change in contact angle is substantial in some pretreatments.
Srikanta Patra,양해식 대한화학회 2009 Bulletin of the Korean Chemical Society Vol.30 No.7
A facile, seed-mediated preparation method of trimetallic Au@Pb@Pt core-shell nanoparticles is developed. Au nanoparticles are the template seeds onto which sequentially reduced Pb and Pt are deposited. The trimetallic core-shell structure is confirmed by UV-Vis spectroscopy, TEM and EDS analysis, and cyclic voltammetry. The trimetallic Au@Pb@Pt core-shell nanoparticles show high electrocatalytic activity for formic acid and methanol electrooxidation.
표면 플라즈몬 현미경을 이용한 자기조립 단분자막의 이미징
표현봉,신용범,윤현철,양해식,김윤태 한국광학회 2003 한국광학회지 Vol.14 No.1
이차원 표면 플라즈몬의 공명 흡수와 포토 마스크를 이용하여 11-MUA(11-Mercaptoundecanoic acid)와 11-MUOH(11-Mercaptoundecanol) 둥으로 이루어진 자기조립 단분자막(Self-Assembled Monolayer; SAM)의 다채널 영상을 얻었다. 통상의 Photoresist를 이용한 리토그래피 대신에 Thiol bonding의 광산화를 이용하여 패터닝 과정을 줄이고, 백색광 및 대역통과 필터(λ$_{0}$=633nm)를 이용하여 입사광으로써 레이저를 사용할 때 나타나는 간섭무늬를 줄였다. 이로부터 나타나는 이차원 영상의 명암을 정량적으로 보정하면 수 나노미터(nm) 두께의 변화를 측정할 수 있다. 또한 표면 플라즈몬 공명법은 국소화된 근접장 (소산장)을 이용하는 방법으로서, 통상 많이 이용되는 형광법 등에서 나타나는 광탈색(Photobleaching)이나 소광(Quenching) 현상이 없이 시료의 처리가 간단하고, 영상 신호의 시간에 따른 변화가 극히 적으며, 실시간으로 신호의 변화를 측정할 수 있다는 장점이 있다. Multi-channel images of 11-MUA(11-Mercaptoundecanoic acid) and 11-MUOH(11-Mercaptoundecanol) self-assembled monolayers were obtained by using two-dimensional surface plasmon resonance (SPR) absorption. The patterning process was simplified by exploiting direct photo-oxidation of thiol bonding (photolysis) instead of conventional photolithography. Sharper images were resolved by using a white light source in combination with a narrow bandpass filter in the visible region, minimizing the diffraction patterns on the images. The line profile calibration of the image contrast caused by different resonance conditions at each point on the sensor surface (at a fixed incident angle) enables us to discriminate the monolayer thickness in nanometer scale. Furthermore, there is no signal degradation such as photo bleaching or quenching, which are common in the detection methods based on fluorescence.
Seong Jung Kwon,서명은,양해식,김상율,곽주현 대한화학회 2010 Bulletin of the Korean Chemical Society Vol.31 No.11
Conducting polymers (CPs) are widely used as matrixes for the entrapment of enzymes in analytical chemistry and biosensing devices. However, enzyme-catalyzed polymerization of CPs is rarely used for immunosensing due to the difficulties involved in the quantitative analysis of colloidal CPs in solution phase. In this study, an enzyme-amplified electrocatalytic immunosensor employing a CP as a redox marker has been developed. A polyanionic polymer matrix, α-amino-ω-thiol terminated poly(acrylic acid), was employed for precipitation of CP. The acrylic acid group acts as a polyanionic template. The thiol terminus of the polymer was used to produce self-assembled monolayers (SAMs) on Au electrodes and the amine terminus was employed for immobilization of biomolecules. In an enzymeamplified sandwich type immunosensor, the polyaniline (PANI) produced enzymatically is attracted by the electrostatic force of the matrix polymer. The precipitated PANI was characterized by electrochemical methods.
Md. Abdul Aziz,양해식 대한화학회 2007 Bulletin of the Korean Chemical Society Vol.28 No.7
We have developed an electrochemical immunosensor that combines the electrocatalytic property of carbon nanotube and the low background current of indium tin oxide (ITO) electrode. A partial monolayer of carboxylated single-walled carbon nanotube (CCNT) is covalently formed on an ITO electrode modified with amine-terminated phosphonic acid. Nonspecifically adsorbed avidin on the hydrophobic sidewalls of CCNT is used to immobilize biotinylated antibody and to reduce the nonspecific binding to CCNT. The biotinylated antimouse IgG bound on avidin and the antimouse IgG conjugated with alkaline phosphatase (ALP) sandwiches a target mouse IgG. ALP catalyzes the conversion of p-aminophenyl phosphate monohydrate into p-aminophenol, which is electrocatalytically oxidized to p-quinone imine on CCNT surface. Moderate electrocatalytic electrode obtained with the combination of CCNT and ITO allows low detection limit (0.1 ng/mL).
Trypsin Detection Using Electrochemical Reduction-based Redox Cycling
Jeonghwa Shin,Kiryeon Park,박선화,양해식 대한화학회 2021 Bulletin of the Korean Chemical Society Vol.42 No.1
It is more difficult to obtain high signal-to-background ratios in biosensors using electrochemical reduction than using electrochemical oxidation. Here, we present a method for trypsin detection using electrochemical reduction-based redox cycling. Electrochemical-enzymatic (EN) redox cycling and electrochemical-chemical (EC) redox cycling for trypsin detection were tested and compared. Trypsin cleaves a peptide bond in an electrochemically inactive p-aminophenol (AP)-conjugated oligopeptide, and this cleavage results in the release of electrochemically active AP, which is involved in EN and EC redox-cycling reactions. Horseradish peroxidase and cytochrome c (Cyt c) were tested as redox enzymes for EN redox cycling involving a redox enzyme and H2O2. Cyt c was better than horseradish peroxidase, as its use resulted in lower background levels. The trypsin detection based on the EN redox cycling involving Cyt c and H2O2 (~50?ng/mL) exhibited lower detection limits than the detection based on EC redox cycling involving IO3? (~100?ng/mL), because of higher signal levels.