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

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 M for BBP. In addition, finite difference time domain (FDTD) electromagnetic simulations also performed in great agreement with our experimental results.