MESA + Institute for Nanotechnology, University of Twente, Enschede, The Netherlands.
Nanotechnology. 2010 Mar 26;21(12):125605. doi: 10.1088/0957-4484/21/12/125605. Epub 2010 Mar 5.
We demonstrate a simple and versatile way to achieve high yield synthesis of shape- and size-controlled multi-branched gold nanoparticles (MBNPs). Control over the shape of the MBNPs was achieved by varying the ratio of gold to the mild reducing agent ascorbic acid, using a seed-mediated growth approach. Higher ascorbate concentrations resulted in the smoothing of branches, leading to the yield of relatively more isotropic particles. Furthermore, we found that using much higher silver concentrations in the growth solution resulted in the formation of rod-shaped micro-features together with MBNPs; we postulate them to be cetyltrimethyl ammonium silver bromide crystals. The as-prepared MBNPs show interesting tunable optical properties that are strongly influenced by the particle shape. The results are discussed in terms of plasmon coupling between the core and branches of the MBNPs.
我们展示了一种简单而通用的方法，可实现高产率合成具有形状和尺寸可控的多分支金纳米粒子（MBNPs）。通过使用种子介导的生长方法，通过改变金与温和还原剂抗坏血酸的比例来控制 MBNPs 的形状。较高的抗坏血酸浓度会使分支平滑化，从而产生相对更各向同性的颗粒。此外，我们发现，在生长溶液中使用高得多的银浓度会导致形成棒状微特征以及 MBNPs；我们推测它们是十六烷基三甲基溴化铵银晶体。所制备的 MBNPs 显示出有趣的可调谐光学性质，这些性质受颗粒形状的强烈影响。结果根据 MBNPs 的核与分支之间的等离子体耦合进行了讨论。
