Bowtie Nanoantenna with Single-Digit Nanometer Gap for Surface-Enhanced Raman Scattering (SERS)

• DOI: 10.1007/s11468-014-9870-5
• Publication Date: 2014-12-22T07:07:12Z
• Authors: Jian Zhang; Mehrdad Irannejad; Bo Cui
• Keywords: 02 engineering and technology; 0210 nano-technology

Sub-10-nm gaps in noble metal bowtie structures may enable strong enhancement of the near field at the gap. However, it is challenging to define such small gaps using electron beam lithography (EBL) due to the proximity effect. Here, we circumvented this problem by carrying out EBL on a thin membrane that is transparent to incident electrons and thus free from the proximity effect. Nanogaps down to 6 nm were obtained and employed for sensing application based on surface-enhanced Raman scattering (SERS). We achieved a high sensitivity at low concentration of the target molecule with a SERS enhancement factor of 107.