EMPA, Swiss Federal Laboratories for Materials Science and Technology, Laboratory for Mechanics of Materials and Nanostructures, Feuerwerkerstrasse 39, CH-3602 Thun, Switzerland.
Langmuir. 2010 Sep 7;26(17):14364-71. doi: 10.1021/la1016356.
We report a simple synthetic route based on electroless deposition (galvanic displacement) and natural lithography to simultaneously control the shape and organization of Au nanoparticles (NPs). We show for the first time the formation of organized extended domains of Au nanoflowers and nanocrowns with single crystalline tips. The dimension and morphology of the desired nanostructures (NSs) can be tuned easily by controlling the deposition conditions at room temperature using saccharin as an organic additive. The exact role of saccharin on the crystal growth process of Au NPs is also discussed. A systematic surface enhancement Raman spectroscopy (SERS) study of large, ordered areas of organized gold nanoflowers using p-mercaptoaniline (pMA) as the probe molecule shows massive and reproducible enhancements of the Raman signal. By comparing the relative enhancement of the different vibrational modes as a function of the morphology, the specific charge-transfer (chemical effect) SERS mechanism can be distinguished from the general electromagnetic field enhancement (physical effect). A wide range of applications can be envisaged for these SERS substrates.
我们报告了一种基于化学镀（置换反应）和自然光刻的简单合成方法，可同时控制金纳米粒子（AuNPs）的形状和排列。我们首次展示了具有单晶尖端的Au 纳米花和纳米冠的有序扩展畴的形成。通过使用糖精作为有机添加剂，在室温下控制沉积条件，很容易调整所需纳米结构（NS）的尺寸和形态。还讨论了糖精对 Au NPs 晶体生长过程的确切作用。使用对巯基苯胺（pMA）作为探针分子，对大尺寸、有序的 Au 纳米花进行系统的表面增强拉曼光谱（SERS）研究，显示出拉曼信号的大量和可重复增强。通过比较不同振动模式的相对增强作为形态的函数，可以区分特定的电荷转移（化学效应）SERS 机制与一般的电磁场增强（物理效应）。可以设想这些 SERS 衬底的广泛应用。
