Fabrication of Au nanostar/MIL-101(Fe) architecture for surface-enhanced Raman scattering detections

In the surface-enhanced Raman scattering (SERS) measurements, it is very important to fabricate “hot spots” and concentrate the analytes into these regions. In this work, a hybrid structure of Au nanostars (NSs) with high SERS sensitivity and metal-organic framework MIL-101(Fe) with high molecular adsorption capability was constructed as high performance SERS substrate. The MIL-101(Fe) shell between AuNSs is several nanometers, promoting the construct of “hot spots” and the aggregation of target molecules. The as-prepared AuNS/MIL-101(Fe) has achieved high SERS sensitivity, long-time stability, reproducibility, and capability of universal detections. The limit of detection for rhodamine 6 G is down to 0.29 nM. Meanwhile, the SERS activity of AuNS/MIL-101(Fe) is kept for at least 30 days. Furthermore, the relative standard deviations of signals on five substrates are all less than 10 %. The as-prepared AuNS/MIL-101(Fe) also exhibit the SERS activities for various molecules including dyes, organic contaminants, pesticides, and amino acids , indicating that the AuNS/MIL-101(Fe) substrates have wide applications in chemical analysis and environmental monitoring.