化学学报 ›› 2016, Vol. 74 ›› Issue (5): 435-440.DOI: 10.6023/A16010073 上一篇    下一篇

研究论文

P(NIPAM-co-RhBHA)-NP的双重荧光响应行为与影响机制

宋秋生, 周稳, 吴新民, 吴凡   

  1. 合肥工业大学化学与化工学院 合肥 230009
  • 投稿日期:2016-01-31 发布日期:2016-03-03
  • 通讯作者: 宋秋生 E-mail:sqshfut@126.com

Dual Stimulus-responsive Fluorescence Behavior and Mechanism of P(NIPAM-co-RhBHA)-NP

Song Qiusheng, Zhou Wen, Wu Xinmin, Wu Fan   

  1. School of Chemistry and Chemical Engineering, Hefei University of Technology, Hefei 230009, China
  • Received:2016-01-31 Published:2016-03-03

以萘二甲酰亚胺与罗丹明B酰肼基硫脲两种有机荧光染料的光谱重叠特性, 及罗丹明B酰肼基硫脲在pH诱导下的可逆“开-闭”环反应为基础, 分别将其作为荧光共振能量转移(Fluorescence Resonance Energy Transfer, FRET)体系的供、受体, 并与聚N-异丙基丙烯酰胺(PNIPAM)的温敏特性相结合, 通过一系列化学反应, 合成了一种具有双重荧光刺激-响应特性的大分子P(NIPAM-co-RhBHA)-NP. 采用1H NMR、FTIR、UV-vis和GPC对其结构进行了表征. 采用荧光光谱(PL)研究了缓冲溶液中该聚合物对环境温度和pH值的双重荧光响应行为, 并对其影响机制进行了探讨. 结果表明, 酸性条件下大分子中RhBHA和NP-NH2之间会发生荧光共振能量传递; pH值和环境温度变化对大分子P(NIPAM-co-RhBHA)-NP的荧光发射具有显著影响.

关键词: 萘二甲酰亚胺, 罗丹明B酰肼基硫脲, N-异丙基丙烯酰胺, 荧光共振能量传递, 刺激-响应性聚合物

In the present study, based on spectral overlap between 1,8-naphthalimide and N-acrylyl-N'-rhodamine B acylhydrazine thiourea (RhBHA), reversible “on-off” ring reaction of RhBHA at various pH values, and thermosensitive property of poly(N-isopropyl acrylamide) (PNIPAM), a novel linear polymer P(NIPAM-co-RhBHA)-NP was prepared via a series of chemical reactions. Firstly, 4-(2-aminoethyl)amino-N-aminopropane-1,8-naphthalimide (NP-NH2) and RhBHA were prepared respectively, and they were used as the donor and acceptor to construct a fluorescence resonance energy transfer (FRET) system. Secondly, incorporating RhBHA into PNIPAM by reversible addition-fragmentation chain transfer polymerization (RAFT), P(NIPAM-co-RhBHA) was synthesized. Finally, P(NIPAM-co-RhBHA)-NP was fabricated by amide condensation between NP-NH2 and the as-prepared P(NIPAM-co-RhBHA). The structure of P(NIPAM-co-RhBHA)-NP was characterized via 1H NMR, FTIR, UV-vis and GPC. The fluorescence responsive behavior of the polymer to environmental temperature and pH value was investigated by photoluminescence (PL) in buffer solutions, and the mechanism was discussed in detail. The results indicate that, in an acidic solution, energy can be transferred from NP-NH2 moieties to RhBHA moieties via FRET mechanism, either pH values or environmental temperatures play important roles to affect the fluorescence emission of P(NIPAM-co-RhBHA)-NP.

Key words: 1,8-naphthalimide, N-acrylyl-N'-rhodamine B acylhydrazine thiourea, poly(N-isopropyl acrylamide), fluorescence resonance energy transfer, stimulus-responsive polymer