Quasi-periodical 3D hierarchical silver nanosheets with sub-10 nm nanogap applied as an effective and applicable SERS substrate
Surface-enhanced Raman scattering (SERS) is considered as the most promising trace detection method since its first discovery on rough silver electrodes in 1974. After years of development, it has exhibited great potential as a nondamaging single molecule analysis method applied in a wide range of areas, including biological labeling, chemistry, agriculture,[ 4] environmental science, food safety, and so forth. The origin of the SERS effect is still in dispute but there is an agreement on an electromagnetic enhancement mechanism (EM) due to the excitation of the localized surface plasmon resonance (LSPR) on the nanostructures with existance of nanogaps. Enhancement efficiency and applicability are the two factors that evaluate the SERS substrate. The effeciency means the substrate can trace molecules sensitively, reproducibly, and precisely, while the applicability indicates the SERS substrate can be prepared easily at low cost.