Gold nanoparticle-coated silicon cone array for surface-enhanced Raman spectroscopy

We demonstrate a silicon cone array substrate coated with gold nanoparticles and which was highly sensitive, homogeneous, and provided a large area for surface-enhanced Raman spectroscopy (SERS). A deep reactive ion-etching process was used to fabricate the high-density silicon cone array, and gold nanoparticles were formed on the silicon cone surface by magnetron sputtering. The substrate was tested with 10−6 M rhodamine 6 G solution. Enhancement of the substrate was about 60-fold greater than that of flat substrate. Moreover, SERS signals obtained from 24 random areas on the substrate showed good homogeneity with an average standard deviation of 3.9%.