Shu-Ting Li, Yun-Chih Lin, S. Kuo
Jul 31, 2012
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0
Influential Citations
30
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Journal
Polymer Chemistry
Abstract
In this study, tetraphenylthiophene (TP) with aggregation-induced emission enhancement (AIEE) property served as the terminal and central fluorophores of poly(γ-benzyl-L-glutamate) (PBLG)-based polymers of TP1PBLG and TP2PBLG, respectively, to probe the relationship between the secondary structure (α-helix) of polypeptides and the AIEE-operative fluorescence (FL). Intermolecular aggregation of the central TP unit in the di-substituted TP2PBLG is sterically blocked by the large α-helical PBLG chains, which leads to the reduced AIEE-oriented FL. In contrast, the terminal TP units in TP1PBLG can easily approach each other to form aggregates with strong FL. Factors (e.g. solvent annealing) controlling the fraction of the α-helix chain also vary the corresponding emission intensity. The conformational difference between TP1PBLG and TP2PBLG evaluated from the infrared and the X-ray (wide- and small-angle) diffraction spectra is also used to verify its influence on the AIEE-operative FL behavior.