Construction and Application of a pH-Sensitive Nanoreactor via a Double-Hydrophilic Multiarm Hyperbranched Polymer

详细信息    查看全文

• 作者：Lijuan Zhu ; Yunfeng Shi ; Chunlai Tu ; Ruibing Wang ; Yan Pang ; Feng Qiu ; Xinyuan Zhu ; Deyue Yan ; Lin He ; Chengyu Jin ; Bangshang Zhu
• 刊名：Langmuir
• 出版年：2010
• 出版时间：June 1, 2010
• 年：2010
• 卷：26
• 期：11
• 页码：8875-8881
• 全文大小：990K
• 年卷期：v.26,no.11(June 1, 2010)
• ISSN：1520-5827

文摘

A double-hydrophilic multiarm hyperbranched polymer with a hyperbranched poly(amidoamine) (HPAMAM) core and many poly(ethylene glycol) monomethyl ether (MPEG) arms connected by pH-sensitive acylhydrazone bonds (HPAMAM-g-MPEG) was successfully prepared. Benefiting from the cationic dendritic core and PEGylation shell, the double-hydrophilic multiarm hyperbranched polymer was used as a nanoreactor for CdS quantum dots (CdS QDs) synthesis in aqueous solution. The obtained HPAMAM-g-MPEG and CdS/HPAMAM-g-MPEG nanocomposites were carefully characterized by ¹H NMR, ¹³C NMR, Fourier transform infrared spectroscopy (FTIR), ultraviolet−visible absorption spectroscopy (UV−vis), fluorescence spectroscopy (FL), dynamic light scattering (DLS), transmission electron microscopy (TEM), selected area electron diffraction (SAED), and electronic dispersive X-ray spectroscopy (EDS) analysis. Both ¹H NMR and fluorescence spectroscopy investigations confirmed that the acylhydrazone linkage between the dendritic core and linear arms was readily broken under acidic condition (pH <5.5). When MPEG arms departed from the HPAMAM core, the fluorescence intensity of CdS/HPAMAM-g-MPEG nanocomposites greatly increased. Such pH-responsive behavior of CdS/HPAMAM-g-MPEG nanocomposites was utilized as an exploration of a novel fluorescence probe in an acidic lysosome exemplified by COS-7 cells.