| Summary: | 碩士 === 國立中山大學 === 材料與光電科學學系研究所 === 103 === First chapter: Tetraphenylthiophene (TP) with aggregation-enhanced emission (AEE) property was used as terminal fluorophore of the water-soluble poly(γ-propargyl-L-glutamate) (PPLG)-based polymers of TP-PPLG-g-MEO2. In this study, we research various TP-PPLG-g-MEO2 affect aggregation of luminescence. In water, when concentration of TP-PPLG-g-MEO2 achieve CMC, TP-PPLG-g-MEO2 will aggregation to nanoparticle and suddenly increasing emission, and when heating over LCST, TP-PPLG-g-MEO2 will contract and also enhance emission. We use TP-PPLG-g-MEO2 “salt out effect” property to probe salt in water, salt have interaction with side chain MEO2 and peptide main chain to make TP-PPLG-g-MEO2 contract together and change secondary structure to b-sheet conformation to enhance emission. In the strong alkaline media, TP-PPLG-g-MEO2 backbone change to random coil conformation that break intramolecular hydrogen bonding and loss LCST property, TP-PPLG-g-MEO2 become is a micelle like structure, core was hydrophobic TP and shell was hydrophilic polypeptide and particle size about 500nm measure by DLS. In random coil conformation, chain end hydrophobic TP have strong aggregation than in the a-helical and have strong aggregation emission peak. At last, we use TP-PPLG-g-MEO2 to detect BSA. When TP-PPLG-g-MEO2 mixture with BSA, TP-PPLG-g-MEO2 will fall in to BSA and separate to decrease TP-PPLG-g-MEO2 aggregation and emission.
Second chapter: We synthesis polypeptide contain TPA pendent by click reaction. The resulting PPLG-g-TPA contains the crystalline TPA side groups, Tm about 145 oC and is therefore high Tg materials with the desired AIE activity. Due to side chain TPA, PPLG-g-TPA have piezofluorochromic property that have two color between crystal and amorphous state. The lone pair electrons of nitrogen atom in TPA side groups inherit PPLG-g-TPA the sensitivity toward acid HCl and metal ions. Emission of PPLG-g-TPA was progressively decreased upon increasing the amounts of HCl and metal ions in the solutions that can be acid or metal ions sensor.
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