Synthesis of bimetallic Ag-Au nanoparticles for surface-enhanced Raman scattering spectroscopy

In this report, bimetallic Au-Ag nanoparticles were successfully prepared by a chemical strategy using binary reduction agents. The metal ratio in bimetallic nanoparticles can be easily tuned by controlling the metal precursor ratio. Using Rhodamine as a probe molecule, we investigated the surface-enhanced Raman scattering (SERS) activity of synthesized bimetallic Au-Ag nanoparticles. The results demonstrate that our materials allow to enhance about 2×106 times the Raman signal of Rhodamine. Hence, the combination of unique features of two plasmonic metals opens up exciting prospects for the design of an ultra-sensitive sensor based on SERS.