Didodecyldimethylammonium bromide (DDAB) lipid bilayer-protected gold nanoparticles (AuNPs), which were stable and hydrophilic, were synthesized by in situ reduction of HAuCl(4) with NaBH(4) in an aqueous medium in the presence of DDAB. As-prepared nanoparticles were characterized by UV-vis spectra, transmission electron microscopy, dynamic light scattering analysis, and X-ray photoelectron spectroscopy. All these data supported the formation of AuNPs. Fourier transform infrared spectroscopy (FTIR) and differential thermal analysis/thermogravimetric analysis data revealed that DDAB existed in a bilayer structure formed on the particle surface, resulting in a positively charged particle surface. The FTIR spectra also indicated that the DDAB bilayer coated on the surface of AuNPs was probably in the ordered gel phase with some end-gauche defects. On the basis of electrostatic interactions between such AuNPs and anionic polyelectrolyte poly(sodium 4-styrenesulfonate) (PSS), we successfully fabricated (PSS/AuNP)(n)() multilayers on a cationic polyelectrolyte poly(ethylenimine) coated indium tin oxide substrate via the layer-by-layer self-assembly technique and characterized as-formed multilayers with UV-vis spectra and atomic force microscopy.

中文翻译：

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十二烷基二甲基溴化铵脂质双层保护的金纳米颗粒：合成，表征和自组装。

稳定和亲水的十二烷基溴化十二烷基二甲基溴化铵（DDAB）脂质双层保护的金纳米颗粒（AuNPs）是通过在DDAB存在下在水性介质中用NaBH（4）原位还原HAuCl（4）来合成的。通过UV-可见光谱，透射电子显微镜，动态光散射分析和X射线光电子能谱表征所制备的纳米颗粒。所有这些数据支持AuNP的形成。傅立叶变换红外光谱（FTIR）和差热分析/热重分析数据表明，DDAB存在于颗粒表面上形成的双层结构中，从而使颗粒表面带正电。FTIR光谱还表明，包被在AuNPs表面的DDAB双层可能处于有序的凝胶相，带有一些末端胶粘剂缺陷。