u-SiO2纳米粒子复合基底的表面增强拉曼散射性能研究

his paper reports a highly active composite substrate, prepared by mixing Au nanoparticles (NPs) and SiO2 NPs, for strong surface-enhanced Raman scattering (SERS). Using pyridine as a probe molecule, the SERS activity of the composite substrate was investigated by changing the particle number ratio of Au NPs to SiO2 NPs. Our results reveal that the composite substrate can produce comparable SERS signal compared with that from Au NPs over a wide particle number ratios, and produce a maximum signal about 2 times higher than that from pure Au NPs at particle number ratio of 10 : 3.5. This improvement may be because that upon contacting with SERS-inactive SiO2 NPs, the Fermi level of the Au NPs change to some extent that enable charge-transfer between pyridine molecule and Au NPs, that is, facilitating chemical enhancement. This work thus provides an easy way to improve SERS performance of Au NPs.