• 폴리머
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• 제32권5호
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• pp.497-500
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• 2008

폴리스틸렌발포체(스티로폼)를 비롯한 소수성 폴리머의 재활용과 친수성 표면개질의 한 방편으로 산소플라즈마 고정화와 그래프팅법을 이용하여 친수성인 아크릴산과 아크릴아미드단량체를 스티로폼 표면에 도입하였다. 플라즈마 처리에 의한 표면개질의 증거는 ESCA스펙트럼의 O/C와 N/C ratio의 증가, 전계방사현미경의 사진으로부터 박막생성 및 접촉각의 현저한 감소 현상의 관찰로부터 확인하였다. 접촉각은 $84^{\circ}$에서 $18{\sim}19^{\circ}$로 대폭 감소하였으며, 이는 아크릴산보다 아크릴아미드가 결정적 요인이 됨을 알 수 있었다.

• 청정기술
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• 제23권4호
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• pp.408-412
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• 2017

Pigment red 53:1 is a dye used in various products as a component of the inks, suspected of being carcinogenic. Thus, the environmental and occupational issues related to it are important. The enzyme-based approach with reusability has advantages to consume less energy and generate less harsh side- products compared to the conventional strategies including separations, microbe, and electrochemical treatment. The degradation of Pigment red 53:1 by the lignin peroxidase immobilized on the surface of magnetic particles has been studied. The immobilization of the peroxidase was conducted on magnetic particle surface with the treatment of polyethyleneimine, glutaraldehyde, and the peroxidase, in sequence. The immobilization was confirmed using X-ray photon spectroscopy. The absorbance peak of the pigment was monitored at 495 nm of UV/Vis spectrum with respect to time to calculate the catalytic activities of the pigment for the immobilized lignin peroxidase. For the comparison, the absorbance of the lignin peroxidase free in solution was also monitored. The catalytic rate constant values for the free lignin peroxidases and the immobilized those were 0.51 and $0.34min^{-1}$, respectively. The reusable activity for the immobilized lignin peroxidase was kept to 92% after 10 cycles. The stabilities for heat and storage were also investigated for both cases.

• 폴리머
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• 제33권6호
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• pp.602-607
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• 2009

심혈관용 소재로서 혈관내피전구세포의 포획을 통해 in vivo 내피세포화가 가능한 표면을 가진 폴리우레탄 표면을 개발하였다. 혈관내피전구세포의 점착을 유도하는 CD34 단일클론항체(monoclonal antibody, mAb)를 표면에 도입하기 위해, poly (poly (ethylene glycol) acrylate-co-butyl methacrylate), poly (PEGA-co-BMA) 공중합체가 합성되었고, 이를 폴리우레탄 표면에 코팅하여 CD34 단일클론항체를 화학적으로 고정화하였다. 중합된 공중합체의 $^1H$-NMR 분석은 원하는 조성을 가진 poly(PEGA-co-BMA)의 합성이 가능함을 확인해 주었다. 이전 연구에서 개발된 PEG가 그래프트된 폴리우레탄과의 비교를 통해, 본 연구에서 제조된 poly(PEGA-co-BMA)가 코팅된 폴리우레탄 표면이 CD34 mAb의 고정화에 더 효과적인 것으로 나타났으며, 이는 CD34 mAb의 표면밀도와 활성도가 32배 이상 증가된 결과를 통해 증명되었다. 개질된 폴리우레탄 표면의 물리화학적 특성은 XPS와 물 접촉각, AFM에 의해 분석되었으며, 각각의 개질된 표면에 따른 표면의 특이적 성질을 잘 보여주었다. 본 연구에서 얻어진 결과들은 poly(PEGA-co-BMA)의 코팅을 통해 제조된 표면이 CD34 mAb의 고정화에 효과적임을 설명하였으며, 실제로 심혈관용 소재의 개발에 적용 가능성이 크다는 것을 증명해 주었다.

• 대한의용생체공학회:학술대회논문집
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• 대한의용생체공학회 1997년도 춘계학술대회
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• pp.47-50
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• 1997

We synthesized N-Hydroxysuccinimidyl (NHS) azidobenzoate as a cross-linking reagent for immobilization of peptide onto the solid surface. Thin polystyrene(PS) films spin-coated with a NHS azidobenzoate solution were exposed with ultraviolet light at 245nm$(3.3mW/cm^2)$ for 5 min. The NHS active ester groups became covalently attached to the polymer via photogenerated, highly reactive nitrene intermediates derived from NHS azidobenzoate. Using this technique, it is demonstrated that well-defined surface regions can be functionalized with a minimum observable feature size of 1mm for UV exposure. Through reaction of this functionalized PS surface with primary amine-containing biomolecules, biological molecule had been immobilized on the polymer surface.

• Journal of Microbiology and Biotechnology
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• 제29권5호
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• pp.749-757
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• 2019

Nitrilase is a valuable hydrolase that catalyzes nitriles into carboxylic acid and ammonia. Its applications, however, are severely restricted by the harsh conditions of industrial reaction processes. To solve this problem, a nitrilase from Acidovorax facilis 72W was inserted into an Escherichia coli-Bacillus subtilis shuttle vector for spore surface display. Western blot, enzyme activity measurements and flow cytometric analysis results all indicated a successful spore surface display of the CotB-nit fusion protein. In addition, the optimal catalytic pH value and temperature of the displayed nitrilase were determined to be 7.0 and $50^{\circ}C$, respectively. Moreover, results of reusability tests revealed that 64% of the initial activity of the displayed nitrilase was still retained at the $10^{th}$ cycle. Furthermore, hydrolysis efficiency of upscale production of cyanocarboxylic acid was significantly higher in the displayed nitrilase-treated group than in the free group expressed by E. coli (pET-28a-nit). Generally, the display of A. facilis 72W nitrilase on the spore surface of Bacillus subtilis may be a useful method for immobilization of enzyme and consequent biocatalytic stabilization.

• 한국생물공학회:학술대회논문집
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• 한국생물공학회 2001년도 추계학술발표대회
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• pp.859-862
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• 2001

For the development of preferable immunosensor and protein chip, the viologen Langmuir-Blodgett (LB) multilayer was fabricated on the surface, and then protein A was adsorbed on the proposed viologen LB film by electrostatic attractive force. The Immunoglobulin G (IgG) labeled with fluorescence marker was self-assembled on the fabricated protein A film. The topographies of the deposited films were investigated by using atomic force microscope (AFM). The immobilization of IgG was verified by fluorescence spectrum. Such structures can be used as sublayers for various kinds of IgG immobilization toward immunosensors and protein chip.

• Biotechnology and Bioprocess Engineering:BBE
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• 제9권4호
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• pp.241-244
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• 2004

Protein A molecular thin film was fabricated as a platform of antibody-based biosensor. For the immobilization of the protein A thin film, a viologen multilayer was built up using the Langmuir-Blodgett (LB) technique, and then, protein A was adsorbed on the viologen LB film by an electrostatic interaction force, which was formed as a hetero-film structure. For the deposition of viologen, surface pressure area ($\pi$-A) isotherm was investigated. The fabricated protein A-viologen hetero LB film was investigated using atomic force microscopy (AFM). Using the developed molecular film, antibody immobilization and fluorescence measurement was carried out.

• 한국지하수토양환경학회:학술대회논문집
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• 한국지하수토양환경학회 2002년도 총회 및 춘계학술발표회
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• pp.127-130
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• 2002

Recently, the contamination with heavy metals in closed mines has been seriously considered since it can disturb human health through the polluted drinking-water and crops. Therefore, the concerns about the remediation of polluted land and treatment technology for hazardous matters have been accelerated. However, any of practical methods for treatment and/or remediation have not been yet suggested. In this research, a novel technology was studied to immobilize arsenic in tailings and soils disturbed by mining. In this technology, Fenton-like reaction were applied to immobilize arsenic in tailings. In the examination of Fenton-like reaction using pure pyrite, $H_2O$$_2$ and arsenic, the concentrations of extracted arsenic and iron were reduced up to 90 and 75%, respectively From the result of SEM-EDS, the Immobilization of arsenic was observed on the surface of pyrite. Thus, it can be said that the coating and/or adsorption prevents the extraction of arsenic.

• Journal of Microbiology and Biotechnology
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• 제14권5호
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• pp.1043-1046
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• 2004

The stability and electrochemical properties of a self-assembled layer of spinach ferredoxin on a quartz substrate and on a highly oriented pyrolytic graphite electrode were investigated. To fabricate the ferredoxin self-assembly layer, dimyristoylphosphatidylcholine was first deposited onto a substrate for ferredoxin immobilization. Surface analysis of the ferredoxin layer was carried out by atomic force microscopy to verify the ferredoxin immobilization. To verify ferredoxin immobilization on the lipid layer and to confirm the maintenance of redox activity, absorption spectrum measurement was carried out. Finally, cyclic-voltammetry measurements were performed on the ferredoxin layers and the redox potentials were obtained. The redox potential of immobilized ferredoxin had a formal potential value of -540 mV. It is suggested that the redox-potential measurement of self-assembled ferredoxin molecules could be used to construct a biosensor and biodevice.

• 펄프종이기술
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• 제34권5호
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• pp.39-48
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• 2002

The water retention of coating colors can be accurately measured by devices such as an AA-GWR water retention meter whose principle of measurement Is based on pressure filtration of coatings under an externally applied air pressure over a certain period of time. It was hypothesized that such devices could be also used to determine the immobilization solids (IMS) of coating colors by determining a sudden drop in the rate of dewatering, that is, a sudden change in the drainage curves. To test this hypothesis, the immobilization solids of coating colors containing various thickeners and water retention additives at different levels were first accurately measured by a modified immobilization tester based on the well-known gloss drop method, and then their values were compared with those obtained by an AA-GWR water retention tester. They agreed very well and showed that the standard deviation is only 0.14% in the IMS points between both methods. This good agreement was not surprising because both test methods are based on the same end-point, that is, the immobilization solids point at which menisci begin to form at the coating surface. Theoretical considerations supporting this new method for measuring the immobilization solids of coating colors are presented and some recommendations for the test method are discussed. Also, the effect of various thickeners and water retention additives on the properties and printability of coated papers is discussed.