Silver nanoparticles deposited inverse opal film as a highly active and uniform SERS substrate

Ag-decorated TiO 2 inverse opal films (ATIO) with high surface-enhanced Raman scattering (SERS) enhancement were prepared using an electroless deposition process. The Ag nanoparticles (NPs) are well-dispersed and deposited on the edge of macroporous walls. The structure and optical properties of the sample ATIO have been characterized. The Ag-loading cycles and pore sizes of TiO 2 inverse opal are the key factors determining the magnitude of SERS signal enhancement. The optimized ATIO samples exhibit high SERS signal enhancement ability and reproducibility. The enhancement factor about 10 4 and the detection limit of 10 −10   M for R6G were achieved. The further application in detecting malachite green is demonstrated. A limit of detection approximately 10 −9   M was achieved. The results show that the ATIO nanostructure is promising for using as sensor substrates in SERS applications.