Combination of inverted pyramidal nanovoid with silver nanoparticles to obtain further enhancement and its detection for ricin

We have obtained the surface-enhanced Raman scattering substrate by depositing silver nanoparticles on the surface of the inverted pyramidal nanovoid in order to improve the enhance effects. Experimental results showed that the combined substrate exhibited greater enhancement than the nanovoid substrate or nanoparticles. In order to test the SERS activity of the combined substrates, Rh6G and ricin toxin were used as Raman probes. Finite element method was employed to simulate electric field and induced charge distribution of the substrates, which have been used to explore the interaction between nanoparticles and nanovoid as well as mechanism of the great enhancement.