Size-dependent surface enhanced Raman scattering activity of plasmonic AuNS@AgNCs for rapid and sensitive detection...

Phthalate plasticizers (PAEs) are heavily applied to plastic products and poses severe threat to human health. Herein, it is especially urgent to find a stable and reliable method for detecting PAEs. In this report, a Surface Enhanced Raman Scatting (SERS) strategy coupled with plasmonic core-shell Au nanospheres@Ag nanocubes (AuNS@AgNCs) as substrates were employed for the rapid and sensitive detection of Butyl benzyl phthalate (BBP) in liquor samples, and plasmonic core-shell AuNS@AgNCs tend to perform richer localized surface plasmon resonance (LSPR) than AuNS. In this work, different sizes AuNS@AgNCs comprised of Au nanospheres as core and Ag nanocubes as shells were synthesized. Based on this, we then investigated the SERS activity of BBP and crystal violet (CV) reached a maximum level when the thickness of Ag coating shell arrived in a threshold, and even very low signal of trace BBP dissolved in liquor sample can be detected in existence of the plasmonic AuNS@AgNCs active substrate of 50 nm. The sensitivity and repeatability of the optimized size AuNs@AgNCs have been estimated and limits of detection (LOD) was 10^-9 M for BBP. In addition, finite difference time domain (FDTD) electromagnetic simulations also performed in great agreement with our experimental results.