National Institute of Advanced Industrial Science and Technology, 1-8-31 Midorigaoka, Ikeda-city, Osaka 563-8577, Japan.
Langmuir. 2011 Feb 1;27(3):895-901. doi: 10.1021/la103143j. Epub 2010 Dec 28.
A novel method has been developed to fabricate the assembly of Au colloidal nanoparticles (NPs) using SiO(2) monomers. The key strategy was the use of a controlled sol-gel procedure including hydrolysis, deposition, and condensation of tetraethyl orthosilicate (TEOS). Namely, the assembly of Au NPs was created by the anisotropic deposition of SiO(2) monomers and subsequent permanent fixing by the growth of a SiO(2) shell. Various assemblies of Au NPs such as dimer, trimer, and pearl-chain morphology were fabricated by systematically changing the concentration and injection speed of TEOS. A longitudinal plasmon resonance band was observed as a result of the assembly of Au NPs and can be tuned from visible to near-infrared by altering the length of pearl-chain morphology. In addition, single Au NP was homogeneously coated with a SiO(2) shell by means of controlling the deposition rate of SiO(2) monomers during a Stöber synthesis without the use of a silane coupling agent or bulk polymer as the surface primer to render the Au surface vitreophilic. The Au NPs (mean size 11.4 nm in diameter) were thus encapsulated into SiO(2) beads with a wide range of sizes (from 20 to 50 nm in diameter). These pure SiO(2)-coated Au beads with tunable shell thickness should be crucial for biosensors, particularly as Raman-tag particles.
已经开发出一种新方法，使用 SiO2 单体来制造 Au 胶体纳米粒子（NPs）的组装体。关键策略是使用受控的溶胶-凝胶程序，包括四乙氧基硅烷（TEOS）的水解、沉积和缩合。也就是说，通过 SiO2 单体的各向异性沉积和随后通过 SiO2 壳的生长进行的永久固定，来创建 Au NPs 的组装体。通过系统改变 TEOS 的浓度和注入速度，可以制备各种 Au NPs 组装体，例如二聚体、三聚体和珍珠链形态。由于 Au NPs 的组装，观察到纵向等离子体共振带，并且可以通过改变珍珠链形态的长度将其从可见光调谐到近红外。此外，通过控制在 Stöber 合成过程中 SiO2 单体的沉积速率，无需使用硅烷偶联剂或大块聚合物作为表面引发剂，即可均匀地用 SiO2 壳涂覆单 Au NP，使 Au 表面具有亲水性。因此，Au NPs（直径为 11.4nm 的平均尺寸）被封装到具有广泛尺寸（直径为 20 至 50nm）的 SiO2 珠中。这些具有可调壳厚度的纯 SiO2 涂层 Au 珠对于生物传感器尤其重要，特别是作为 Raman 标记颗粒。
