Facile synthesis of large-scale Ag nanosheet-assembled films with sub-10nm gaps as highly active and homogeneous SERS substrates

• Published in: Applied surface science 2013-01, Vol.264, p.383-390
• Main Authors: Li, Zhongbo, Meng, Guowen, Liang, Ting, Zhang, Zhuo, Zhu, Xiaoguang
• Format: Article
• Language: English
• Subjects: Galvanic cell; Photolithography; Silver; Surface-enhanced Raman scattering
• ISSN: 0169-4332; 1873-5584
• DOI: 10.1016/j.apsusc.2012.10.031

[Display omitted] ► Homogeneous Ag nanosheet-assembled films were prepared via galvanic cell reactions. ► The morphology of the films can be controlled in conjunction with photolithography. ► The Ag nanosheet-assembled films exhibit highly active and homogeneous SERS effect. ► The films can be used as reliable SERS substrates for rapid detection of PCBs. We report a facile low-cost synthetic approach to large-scale Ag nanosheet-assembled films with a high density of uniformly distributed sub-10nm gaps between the adjacent nanosheets on Si substrates via galvanic cell reactions. The distribution density of Ag nanosheets on substrates could be tailored by tuning the duration of the HF-etching and the concentration of citric acid in the solution. Furthermore, in conjunction with a conventional photolithography, highly uniform patterned Ag nanosheet-assembled structures with different morphologies can be achieved on Si substrates via galvanic-cell-induced growth. By using rhodamine 6G as a standard test molecule, the large-scale Ag nanosheet-assembled films exhibit highly active and homogenous surface-enhanced Raman scattering (SERS) effect and also show promising potentials as reliable SERS substrates for rapid detection of trace polychlorinated biphenyls (PCBs).