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Rhodamine spirolactam sensors operated by sulfur-cooperated metal complexation
Heo, Gisuk,Lee, Dahye,Kim, Chi Gwan,Do, Jung Yun Elsevier 2018 Spectrochimica acta. Part A, Molecular and biomole Vol.188 No.-
<P><B>Abstract</B></P> <P>New rhodamine Schiff base sensors were developed to improve selective sensing by introducing sulfide, ester, and dithiocarbonate groups, as well as using ketones coupled to rhodamine-hydrazine. Metal sensing proceeded through the 1:1 complexation of the metal ion for most sensors in the presence of Cu<SUP>2+</SUP> and Hg<SUP>2+</SUP>. A sensor carrying a dithiocarbonate group responded selectively to Hg<SUP>2+</SUP> showing a strong colorimetric change and intense fluorescence. The association constants of the sensors were determined from a linear plot performed at micro-molar concentrations to afford values in the range of 10<SUP>4</SUP>. Sensing was interrupted at the initial time of Hg<SUP>2+</SUP> exposure due to the isomerization of imine and preferential metal bonding of two dithiocarbonate groups regardless of the main structure of rhodamine. The sensors exhibited the reversible and reproducible performance for Hg<SUP>2+</SUP> sensing.</P> <P><B>Highlights</B></P> <P> <UL> <LI> Dithiocarbonate group contributes to Hg sensing of new rhodamine sensor. </LI> <LI> Cooperative metal binding of proximal groups are discussed. </LI> <LI> Sensing properties are compared by association constants. </LI> </UL> </P> <P><B>Graphical abstract</B></P> <P>[DISPLAY OMISSION]</P>
고리형 황화물을 포함하는 폴리아크릴레이트 합성과 설폭사이드 및 설폰 변환을 통한 굴절률 변화
허기석(Gisuk Heo),김새미(Saimi Kim),도정윤(Jung Yun Do) 한국고분자학회 2016 폴리머 Vol.40 No.3
황을 포함하는 고리형 아크릴레이트 단분자를 사용하여 고굴절률의 공중합 아크릴고분자 4종을 합성하였다. 황을 포함한 7-각 고리, 1,3-dithiane, 1,3-dithiolane 유도체를 사용하여 4가지의 아크릴 단분자를 합성하였고, 이를 methyl methacrylate(MMA)와 중량비로 3:7의 공중합고분자를 합성하였다. 오존(O₃)과 3-chloroperoxybenzoic acid (m-CPBA)를 사용하여 고분자에 포함된 황을 산화시켜 각각 SO와 SO₂를 갖는 고분자를 얻었다. 적외선 흡수 분광법(FTIR)과 수소핵자기공명분광(1H NMR) 분석을 통해 이러한 산화반응이 선택적으로 잘 진행되었음을 확인하였다. 합성된 고분자에 포함된 황의 함량에 따라 굴절률이 증가되는 것을 관찰하였다. 황이 SO로 산화되었을 때는 고분자의 굴절률이 증가하였고 SO₂로 산화되었을 때는 크게 감소하였다. SO₂를 갖는 단분자로 합성된 고분자와, 고분자의 산화로 SO₂ 를 갖는 고분자가 서로 유사한 성질을 보임으로써 고분자에 존재하는 황이 대부분 산화되었음을 확인하였다. 황산화 반응을 통해 고분자의 Abbe number는 증가되었다. 파장에 따른 굴절률을 계산하였고 산화반응을 통한 굴절률 변화가 모든 파장에 대해 유사하게 일어났음을 확인하였다. Polyacrylates with pending alkylsulfur groups were prepared to examine the changes in refractive index (RI) induced by sulfur oxidation. Four methacrylate monomers having cyclic alkylsulfur groups, such as 1,3-dithiane and 1,3- dithiolane derivatives, and 3,6-dithiacycloheptanol were developed. The monomers were copolymerized with methyl methacrylate through a radical polymerization. Oxidation of the prepared sulfur-polymers by O₃ and 3-chloroperoxybenzoic acid led to the formation of the corresponding SO and SO₂-polymers, respectively. The selective transformation of sulfur occurred completely and confirmed by FTIR and 1H NMR analysis. The RI of the polymer increased and decreased due to the formation of SO and SO₂, respectively. The SO₂-polymer exhibited a RI comparable to a polymer that was prepared using a sulfone-monomer. The Abbe number of the polymer increased after oxidation. The RI dispersion over various wavelengths was compared before and after oxidation.
Heo, Gisuk,Son, Kiseo,Jeong, Yeon Hee,Kim, Chi Gwan,Do, Jung Yun American Scientific Publishers 2017 Journal of Nanoscience and Nanotechnology Vol.17 No.8
<P>New Rhodamine derivatives were developed from ketohydrazones. 2,4-Pentanedione and 1,3-cyclohexanedione condensation of rhodamine-hydrazine afforded a stable enol hydrazone and enamine rhodamines via equilibrium shifts. Enamine rhodamine exhibited strong pH sensitivity. 2-Cyclohexanedione rhodamine emitted a strong fluorescence as a selective Al3+ sensing probe. The binding constants of the enol hydrazone rhodamine were 2.0x10(4) M-1 (Al3+) and 5.4x10(4) (Cu2+).</P>
김재현(Jaehyun Kim),정기석(Gisuk Jung),강연식(Yeonsik Kang) 한국소성가공학회 2010 한국소성가공학회 학술대회 논문집 Vol.2010 No.10
An automotive steel part is required to evaluate its performance and feasibility in the early stage of vehicle development. It is manufactured using prototype die. The hydroforming prototype die for a hydroformed part is expensive as its massive production die. The high cost of the hydro forming prototype die makes engineer to choose a conventional stamping method before hydroforming technology without any evaluations of hydroformed parts. To reduce the cost of hydroforming prototype die plastics are considered. In this paper mono cast nylon for die material is used to evaluate the feasibility of hydro formed parts. The manufacturing time and cost of prototype die can be saved with the die material, mono cast nylon. And the geometry accuracy of the part formed through the mono cast nylon die can be fulfilled with the tolerance ± 1㎜.
실리카 나노입자에 도입된 로다민 화학센서 개발과 금속이온 검출
신상빈(Sang Bin Shin),이다혜(Dahye Lee),허기석(Gisuk Heo),도정윤(Jung Yun Do) 한국고분자학회 2020 폴리머 Vol.44 No.6
실리카 결합 로다민 화학센서 물질을 개발하고 수용액에 분산시켜 금속이온의 검출 특성 연구를 하였다. 락톤 구조와 락탐 구조를 갖는 로다민 유도체가 결합된 2종의 실리카 나노입자를 제조하였고 pH와 다양한 금속 이온에 노출시켜 입자의 색 변화를 관찰하였다. 실리카로 구성된 내부와 로다민으로 결합된 외부를 갖는 이중구조의 나노입자를 설계하였고, 테트라에톡시 실란과, 실란이 도입된 로다민 유도체를 한 반응기 내에서 단계적으로 도입하는 방법으로 수백 나노 크기의 구형의 실리카 입자를 제조하였다. 금속이온(Hg<SUP>2+</SUP>, Fe<SUP>3+</SUP>, Al<SUP>3+</SUP>)에 선택적 결합력을 갖는 로다민 유도체의 특성은 실리카 입자에 결합된 상태에서도 유사하게 관찰되었다. 로다민의 락톤 작용기는 실리카표면에서 부분적인 고리열림반응이 진행되어 색상을 갖는 실리카 형성을 하였고 센서물질로서 적합하지 않았다. 반면, 락탐 구조의 로다민은 실리카 표면에서 안정되어 무색의 입자 상태를 유지하였고 이온 검출에서 큰 소광비에 따른 뚜렷한 변색 특성을 보였다. The preparation of silica-supported rhodamine chemosensors is described. Metal sensing properties are collected as the silica sensors dispersed into aqueous solution. Rhodamine derivatives with lactone and lactam structure on the silica surface were characterized in the condition of pH and with several metal ions. A double layered structure, composed of silica core and rhodamine shell, was achieved in one-pot synthesis of nano-sized silica particles through controlled addition of tetraethoxysilane and silane-bound rhodamines. Color change of the silica particle was observed from colorless to pink, as exposed on Hg<SUP>2+</SUP>, Fe<SUP>3+</SUP>, and Al<SUP>3+</SUP>. The lactone moiety of a rodamine derivative was partially hydrolyzed on the silica surface to exhibit pale color while the lactam was stable to maintain colorless turn-off state, leading to large extinction ratio in sensing.
N-Glycan Analysis of Recombinant Human Erythropoietin Produced by Different Cell Culture Methods
Ohseok KWON,Seonyeong BAK,Miseop CHOI,Keunjun KIM,Kyungju HAN,Youngjun SEO,Gihyun KIM,Kyungtak NAM,Jusun NAM,Youngeun KIM,Gisuk JUNG,Kyungmin BAEK,Sookyung SUH,Seunghwa HONG 한국생물공학회 2008 한국생물공학회 학술대회 Vol.2008 No.10