Department of Chemistry, Howard University, Washington, DC 20059, United States.
Spectrochim Acta A Mol Biomol Spectrosc. 2011 Aug;79(3):456-61. doi: 10.1016/j.saa.2011.03.009. Epub 2011 Mar 12.
SERS active surfaces were prepared by depositing silver films using Tollen's reaction on to barium titanate beads. The SERS activity of the resulting surfaces was probed using two thiols (benzene thiol and 1,2-benzene dithiol) and rhodamine 6G. The intensity of the SERS signal for the three analytes was investigated as a function of silver deposition time. The results indicate that the SERS intensity increased with increasing thickness of the silver film until a maximum signal intensity was achieved; additional silver deposition resulted in a decrease in the SERS intensity for all of the studied molecules. SEM measurement of the Ag coated barium titanate beads, as a function of silver deposition time, indicate that maximum SERS intensity corresponded with the formation of atomic scale islands of silver nanoparticles. Complete silver coverage of the beads resulted in a decreased SERS signal and the most intense SERS signals were observed at deposition times of 30 min for the thiols and 20 min for rhodamine 6G.
通过在钛酸钡珠上进行托伦反应沉积银膜，制备了 SERS 活性表面。使用两种硫醇（苯硫醇和 1,2-苯二硫醇）和罗丹明 6G 探测所得表面的 SERS 活性。研究了三种分析物的 SERS 信号强度随银沉积时间的变化。结果表明，随着银膜厚度的增加，SERS 强度增加，直到达到最大信号强度；对于所有研究的分子，进一步的银沉积导致 SERS 强度降低。SEM 测量表明，随着银沉积时间的增加，Ag 涂覆的钛酸钡珠的表面形成了原子级银纳米粒子岛。银珠的完全覆盖导致 SERS 信号降低，在硫醇的沉积时间为 30 分钟和罗丹明 6G 的沉积时间为 20 分钟时观察到最强的 SERS 信号。
