Gold nanoparticle-based core-shell and hollow spheres and ordered assemblies thereof
Gold nanoparticle-based core-shell and hollow spheres and ordered assemblies thereof
复制标题
DOI：
10.1021/cm031014h
复制
发表时间：
2003-08-12
影响因子：
8.6
通讯作者：
Caruso, F
中科院分区：
文献类型：
--
作者：
Liang, ZJ;Susha, A;Caruso, F
我们报道了基于金纳米粒子(Au-NP)的核壳粒子和中空球的制备和表征，以及由它们自组装得到的有序结构。用逐层法制备了由聚苯乙烯(PS)核和聚电解质(PE)或Au-NP/PE壳层组成的包覆粒子，即通过将相反电荷的PE依次吸附到PS核上或通过将金纳米粒子渗透到PS粒子上预组装的PE多层膜中来制备包覆粒子。通过改变预组装金纳米颗粒渗入其中的PE层的数量和额外的化学镀金来改变金纳米颗粒基涂层的厚度。通过焙烧或在四氢呋喃中溶解PS核，可以从核壳粒子中获得空心球。包覆的胶体被用作构建有序颗粒组装的构建块。采用了两种不同的方法来形成有序粒子结构。第一种方法是重力沉积Au-NP/PE包覆的PS球，而第二种方法是形成有序的PE包覆的PS球，然后用金纳米粒子渗透。随后，通过去除PS核，从有序的核-壳颗粒组件中制备了3D大孔(“中空”)有序结构。核壳和中空Au-NP/PE微球的紫外-可见吸收光谱以及这些粒子的三维有序组装显示，相对于溶液中的金纳米粒子，等离子激元共振带红移。Au-NP/PE中空微球的三维有序结构的近红外反射光谱显示，在核溶解之前，Bragg反射峰相对于相应的结构蓝移。所描述的策略为从核壳和中空胶体中制备粒子组件开辟了一条新的途径，这可能为它们在光子学、光电子学和催化等领域的应用提供新的机会。
We report on the preparation and characterization of gold nanoparticle (Au-NP)-based core-shell particles and hollow spheres and of ordered structures obtained from their self-assembly. Coated particles, comprising polystyrene (PS) cores and polyelectrolyte (PE) or Au-NP/PE shells, were prepared by the layer-by-layer technique, that is, via the sequential adsorption of oppositely charged PEs onto PS cores, or by the infiltration of gold nanoparticles into preassembled PE multilayers onto PS particles, respectively. The thickness of the gold nanoparticle-based coatings was varied by altering the number of preassembled PE layers into which gold nanoparticles were infiltrated and by additional electroless gold plating. Hollow spheres were obtained from the core-shell particles by either calcination or by dissolution of the PS core by exposure to tetrahydrofuran. The coated colloids were used as building blocks for the construction of ordered particle assemblies. Two different approaches were employed to form the ordered particle structures. The first involved the gravity sedimentation of Au-NP/PE-coated PS spheres, while the second method entailed the formation of ordered assemblies of PE-coated PS spheres, followed by infiltration with gold nanoparticles. 3D macroporous ("hollow") ordered structures were subsequently prepared from the ordered core-shell particle assemblies by removal of the PS cores. UV-visible absorption measurements of core-shell and hollow Au-NP/PE microspheres, and 3D ordered assemblies of these particles, show red-shifted plasmon resonance bands relative to the gold nanoparticles in solution. Near-IR reflectance spectra of the 3D ordered structures of hollow Au-NP/PE microspheres show Bragg reflectance peaks that are blue-shifted relative to the corresponding structures prior to dissolution of the core. The strategy described opens a new avenue to the production of particle assemblies derived from core-shell and hollow colloids, which may provide new opportunities for their application in areas such as photonics, photoelectronics, and catalysis.