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

作者：Song Qiusheng^*; Zhou Wen; Wu Xinmin; Wu Fan

来源：Acta Chimica Sinica, 2016, 74(5): 435-440.

DOI：10.6023/A16010073

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

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 H-1 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.

• 出版日期2016-5-15
• 单位合肥工业大学