A Chemical Route To Increase Hot Spots on Silver Nanowires for Surface-Enhanced Raman Spectroscopy Application

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• 作者：Madeline Shuhua Goh ; Yih Hong Lee ; Srikanth Pedireddy ; In Yee Phang ; Weng Weei Tjiu ; Joel Min Rui Tan ; Xing Yi Ling
• 刊名：Langmuir
• 出版年：2012
• 出版时间：October 9, 2012
• 年：2012
• 卷：28
• 期：40
• 页码：14441-14449
• 全文大小：446K
• 年卷期：v.28,no.40(October 9, 2012)
• ISSN：1520-5827

文摘

The effective number of surface-enhanced Raman spectroscopy (SERS) active hot spots on plasmonic nanostructures is the most crucial factor in ensuring high sensitivity in SERS sensing platform. Here we demonstrate a chemical etching method to increase the surface roughness of one-dimensional Ag nanowires, targeted at creating more SERS active hot spots along Ag nanowire鈥檚 longitudinal axis for increased SERS detection sensitivity. Silver nanowires were first synthesized by the conventional polyol method and then subjected to chemical etching by NH₄OH and H₂O₂ mixture. The surfaces of silver nanowires were anisotropically etched off to create miniature 鈥渂eads on a string鈥?features with increased surface roughness while their crystallinity was preserved. Mapping of single-nanowire SERS measurements showed that the chemical etching method has overcome the limitation of conventional one-dimensional Ag nanowires with limited SERS active area at the tips to produce etched Ag nanowires with an increase in Raman hot spots and polarization-independent SERS signals across tens of micrometers length scale.