Silver nanocubes with high SERS performance

•Ag nanocubes with tunable edge lengths have been successfully synthesized.•The E-field intensity at the Ag cube edges and vertexes is significantly enhanced.•Ag nanocubes exhibited a much higher SERS performance compared with Ag nanospheres.•The size and shape effects of Ag nanocubes were investigated. Hot spots have been considered as a dominant role in surface enhancement Raman scattering (SERS). Here, we investigated the size and shape effect of Ag nanocubes in surface plasmon response and SERS by both experiment and theory simulation method. Silver nanocubes with abundant “hot spots” were synthesized by a polyol method and utilized as electrodes for achieving high SERS enhancement. The absorption wavelengths of the nanocubes were tunable by changing the edge lengths of the nanoparticles. Finite-difference time-domain (FDTD) simulations were employed to investigate the local E-field generation around silver (Ag) nanocubes indicating remarkable E-field enhancement at the edges and vertexes known as “hot spots”. Then, the SERS analyses demonstrated that the SERS activity of various Ag nanocubes using crystal violet (CV) as probe molecules showed a significant enhancement. The enhancement factors of SERS show strong sensitivity between the nanoparticle size and shape. Moreover, the enhancement for CV on Ag nanocubes was significantly higher than for Ag nanospheres. Therefore, the stable and high-performance of Ag nanocubes SERS system shows great application prospects in both scientific researches and practical application.