Multicompartment Polymer Nanostructures with Ratiometric Dual-Emission pH-Sensitivity

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• 作者：Guorong Sun ; Honggang Cui ; Lily Yun Lin ; Nam S. Lee ; Chao Yang ; William L. Neumann ; John N. Freskos ; Jeng J. Shieh ; Richard B. Dorshow ; Karen L. Wooley
• 刊名：Journal of the American Chemical Society
• 出版年：2011
• 出版时间：June 8, 2011
• 年：2011
• 卷：133
• 期：22
• 页码：8534-8543
• 全文大小：1317K
• 年卷期：v.133,no.22(June 8, 2011)
• ISSN：1520-5126

文摘

Pyrazine-labeled multicompartment nanostructures are shown to exhibit enhanced pH-responsive blue-shifted fluorescence emission intensities compared to their simpler core鈥搒hell spherical analogs. An amphiphilic linear triblock terpolymer of ethylene oxide, N-acryloxysuccinimide, and styrene, PEO₄₅-b-PNAS₁₀₅-b-PS₄₅, which lacks significant incompatibility for the hydrophobic block segments and undergoes gradual hydrolysis of the NAS units, underwent supramolecular assembly in mixtures of organic solvent and water to afford multicompartment micelles (MCMs) with a narrow size distribution. The assembly process was followed over time and found to evolve from individual polymer nanodroplets containing internally phase segregated domains, of increasing definition, and ultimately to dissociate into discrete micelles. Upon covalent cross-linking of the MCMs with pH-insensitive pyrazine-based diamino cross-linkers, pH-responsive, photonic multicompartment nanostructures (MCNs) were produced. These MCNs exhibited significant enhancement of overall structural stability, in comparison with the MCMs, and internal structural tunability through the cross-linking chemistry. Meanwhile, the complex compartmentalized morphology exerted unique pH-responsive fluorescence dual-emission properties, indicating promise in ratiometric pH-sensing applications.