In Situ Detection of Trace Furfural in Aqueous Solution Based on Au Nanoparticle/Au Film Surface-Enhanced Raman Spectroscopy

Figure 1

Schematic of the basic principle of Au film decorated by (a) monolayer and (b) multiple layers of AuNPs. The interparticle spacing ranged from 1 nm to 100 nm. In the Au colloid-modified Au film system, hot spots appear in the gaps between AuNPs and Au film. As the number of layers increases, additional hot spots from AuNPs on the additional layers are formed and the coupling effect is enhanced for the induced nanogap.