Atomically Precise Silver Clusters as New SERS Substrates
Atomically Precise Silver Clusters as New SERS Substrates
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DOI：
10.1021/jz4014097
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发表时间：
2013-08-15
影响因子：
5.7
通讯作者：
Pradeep, Thalappil
中科院分区：
文献类型：
--
作者：
Chakraborty, Indranath;Bag, Soumabha;Pradeep, Thalappil
表面增强拉曼散射(SERS)衬底是由硫代配体保护的原子精确的银团簇Ag-152。该团簇对结晶紫的拉曼信号有很强的增强作用，增强因子为1.58×10(9)。该底物对从染料到生物分子的广泛系统的适应性被证明。采用固相滴注法，SERS信号定位在Ag-152微晶上，拉曼光谱证实了这一点。团簇良好的周期性、等离子体性质以及缺乏可见发光是造成这种大增强的主要原因。将SEA与较小的团簇和较大的纳米颗粒进行了比较，发现Ag-152的尺寸区域是最佳的。为了更详细地了解SERS活性，进行了几个对照实验。这种方法具有广泛的适应性，因为团簇可以很容易地滴落在纸、棉花等任何表面上，以产生有效的SERS介质。这项工作表明，原子精确的星系团通常可以显示SERS活动。
An atomically precise silver cluster, Ag-152 protected with thiolate ligands, was used as a surface-enhanced Raman scattering (SERS) substrate. The cluster shows intense enhancement of Raman signals of crystal violet with an enhancement factor of 1.58 x 10(9). Adaptability of the substrate for a wide range of systems starting from dyes to biomolecules is demonstrated. Solid-state drop casting method was used here, and SERS signals were localized on the Ag-152 crystallites, confirmed from Raman images. Excellent periodicity of clusters, their plasmonic nature, and absence of visible luminescence are the main reasons for this kind of large enhancement. SEAS was compared with smaller clusters and larger nanoparticles, and the size regime of Ag-152 was found to be optimum. Several control experiments were done to understand the SERS activity in detail. The method has wide adaptability as the cluster can be easily drop-casted on any surface like paper, cotton, and so forth to produce effective SERS media. The work suggests that atomically precise clusters, in general, can show SERS activity.