Dense layers of overlapping three-dimensional (3D) gold nanodendrites characterized by high specific surfaces as well as by abundance of sharp edges and vertices creating high densities of SERS hotspots are promising substrates for SERS-based sensing and catalysis. We have evaluated to what extent structural features of 3D gold nanodendrite layers can be optimized by the initiation of 3D gold nanodendrite growth at gold particles rationally positioned on silicon wafers. For this purpose, galvanic displacement reactions yielding 3D gold nanodendrites were guided by hexagonal arrays of parent gold particles with a lattice constant of 1.5 μm obtained by solid-state dewetting of gold on topographically patterned silicon wafers. Initiation of the growth of dendritic features at the edges of the gold particles resulted in the formation of 3D gold nanodendrites while limitation of dendritic growth to the substrate plane was prevented. The regular arrangement of the parent gold particles supported the formation of dense layers of overlapping 3D gold nanodendrites that were sufficiently homogeneous within the resolution limits of Raman microscopy. Consequently, SERS mapping experiments revealed a reasonable degree of uniformity. The proposed preparation algorithm comprises only bottom-up process steps that can be carried out without the use of costly instrumentation.

中文翻译：

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评估通过模板化电位移反应获得的3D金纳米树突层，用于SERS传感和非均相催化†

重叠的三维（3D）金纳米树突的致密层，其特征在于高比表面以及大量的尖锐边缘和顶点，从而形成了高密度的SERS热点，是用于基于SERS的传感和催化的有前途的基质。我们已经评估了在合理位置位于硅晶圆上的金颗粒上启动3D金纳米树突生长可以在多大程度上优化3D金纳米树突层的结构特征。为此，通过在形貌图案化的硅晶片上对金进行固态去湿获得的晶格常数为1.5μm的母体金颗粒的六边形阵列引导产生3D金纳米树枝晶的电流置换反应。在金颗粒的边缘开始树枝状特征的生长的引发导致形成3D金纳米树枝状晶体，同时防止了树枝状生长对基底平面的限制。母体金颗粒的规则排列有助于形成重叠的3D金纳米树突的致密层，该致密层在拉曼显微镜的分辨率范围内足够均匀。因此，SERS作图实验揭示了合理的均匀度。所提出的准备算法仅包括自下而上的处理步骤，无需使用昂贵的仪器即可执行该步骤。母体金颗粒的规则排列有助于形成重叠的3D金纳米树突的致密层，该致密层在拉曼显微镜的分辨率范围内足够均匀。因此，SERS作图实验揭示了合理的均匀度。所提出的准备算法仅包括自下而上的处理步骤，无需使用昂贵的仪器即可执行该步骤。母体金颗粒的规则排列有助于形成重叠的3D金纳米树突的致密层，该致密层在拉曼显微镜的分辨率范围内足够均匀。因此，SERS作图实验揭示了合理的均匀度。所提出的准备算法仅包括自下而上的处理步骤，无需使用昂贵的仪器即可执行该步骤。