Abstract
Plasmonic noble metal nanocrystals with interior nanogaps have attracted great attention in surface-enhanced Raman scattering (SERS) applications due to the presence of built-in hotspots. Herein, we report a synthesis route to holey Au-Ag alloy nanoplates by controlled galvanic replacement with Ag nanoplates as the sacrificial template, a sulfite-coordinated Au(i) salt as the Au source, and polyvinylpyrrolidone (PVP) as the capping agent. PVP helps regulate the anisotropic growth of nanopores on the Ag nanoplates to afford a highly holey nanostructure, and the monovalent Au(i) salt plays a critical role in stabilizing these holey nanoplates by rapidly enriching Au in the alloy nanostructures. Numerical simulations and experimental results suggest that these holey Au-Ag alloy nanoplates possess enormous internal hotspots for high sensitivity in the SERS analysis, and high stability for excellent reliability of the analysis under many harsh conditions. We believe that this strategy is potentially applicable to the synthesis of many other types of plasmonic nanostructures with inherent nanogaps for many sensing and imaging applications.
| Original language | English |
|---|---|
| Pages (from-to) | 15689-15695 |
| Number of pages | 7 |
| Journal | Nanoscale |
| Volume | 8 |
| Issue number | 34 |
| DOIs | |
| State | Published - Sep 14 2016 |
| Externally published | Yes |
Funding
C. G. acknowledges the support from the National Natural Science Foundation of China (21301138), the startup fund, and operational fund for the Center for Materials Chemistry from Xi'an Jiaotong University. Y. Y. acknowledges support from the U.S. National Science Foundation (CHE-1308587). The authors thank Prof. Liqing Huang at School of Science, Xi'an Jiaotong University for help with FDTD simulations.
| Funders | Funder number |
|---|---|
| National Science Foundation | 1308587, CHE-1308587 |
| National Natural Science Foundation of China | 21301138 |
| Xi’an Jiaotong University |