Synthesis of Poly(N-phenylmaleimide) and Characterization of Fluorescence Properties for Biomedical Applications
- 발행기관 포항공과대학교 일반대학원
- 지도교수 박문정
- 발행년도 2013
- 학위수여년월 2013. 8
- 학위명 석사
- 학과 및 전공 일반대학원 첨단재료과학부
- 세부전공 Material Chemistry
- 실제URI http://www.dcollection.net/handler/postech/000001622451
- 본문언어 영어
- 저작권 포항공과대학교 논문은 저작권에 의해 보호받습니다.
초록/요약
We synthesized poly(N-phenylmaleimide) by anionic ring opening polymerization method that have light emitting property for biomedical applications, especially sensors. Many polymer based sensors for biomolecules are based on turn-off fluorescence under target substance exposure. Due to the low sensitivity of turn-off type sensors to human naked eye, several attempts have been done to develop turn-on type sensors. Not like turn-off sensors, turn-on type sensor has advantage, easy to find the sensing target material with low concentration. So, for biomolecule sensing, we need to develop new polymeric material suitable for turn-on type sensor. Series of poly(N-phenylmaleimide) have been synthesized by varying initiators through anionic polymerization method. The synthesized polymer shows different light emitting properties according to its initiators. Polymers synthesized by alkali-metal tert-butoxide type of initiator emit yellow color. On the other hand, using n-butyllithium as initiator case, green emission was observed. For understanding different fluorescence properties of synthesized polymers, we carried out 1H and 13C NMR analysis for studying tacticity of polymers. Through the analysis we can assume that different portion of threo-disyndiotactic and threo-diisotactic causes the differences in wavelength of emitted wavelength. At the same time, poly(N-phenylmaleimide) shows strong pH-dependent fluorescence properties. Under acid condition, the polymer shows quenched fluorescence properties. The fluorescence from acidified polymer solution became recovered when the surroundings became neutral. To understand the stimuli-responsive behavior of poly(N-phenlmaleimide), we suggest the mechanism of fluorescence quenching. The peak disappearance under acidic condition, we assume the changes in the state of amines in N-phenylmaleimide, repeating unit. Forming and collapse of quaternary amines causes such an fluorescence changing of poly(N-phenylmaleimide). For biomedical application of poly(N-phenylmaleimide), human creatine kinase M (CKM) and interferon gamma (IFN-γ) were used. Those proteins are strongly related to common diseases, sensing these proteins can help early diagnosis. The principles of sensing proteins by using poly(N-phenylmaleimide) is accommodation of protons according their PI values. Under acidic condition, proteins accommodate protons and their surface charges became positive and in here different PI values causes different sensing performance. In the presence of few nanomole of proteins, pre-quenched fluorescence by acid became recovered. The limit concentration of proteins for sensing is different according to their PI values, 6.8 for CKM and 11 for IFN-γ.
more목차
Chapter 1. Introduction 1
1.1 Biomolecule Sensing 1
1.2 Strategy .2
1.3 References 3
Chapter 2. Synthesis of Poly(N-phenylmaleimide) and Characterization of its Fluorescence Property 7
2.1 Experimental 7
2.2 Result and Discussions 10
2.3 Conclusions 19
2.4 References 20
Chapter 3. Protein Sensing based on Stimuli-responsive Fluorescence of Poly(N-
phenylmaleimide) 21
3.1 Experimental 21
3.2 Results and discussions 23
3.3 Conclusions 28
3.4 References 29
요약문 (한글) 30
감사의 글 32
Curriculum Vitae 34
Publications 35