Gap controlled self-assembly Au@Ag@Au NPs for SERS assay of thiram

Abstract

Thiram (TRM), one dithiocarbamate fungicide, is hazardous due to its ever-growing threat to our production and living. In order to detecting TRM more sensitively, a subtle surface-enhanced Raman scattering (SERS) substrate was reported to achieve TRM detection based on oil-water biphasic self-assembly interface of multi-interstitial Au@Ag@Au NPs crosslinking with 4,4′ -Diamino-p-Terphenyl (DATP). This Au@Ag@Au@DATP array shows a noteworthy enhanced Raman signal and stability by controlling the inter-particle spacing of Au@Ag@Au NPs, which overcomes problems of traditional randomly self-assembly methods without cross linker. The Au@Ag@Au@DATP array attained the limit of detection (LOD) of 7.56 × 10−3 ppb for TRM. In addition, this work gives a new approach for controlling gap of SERS hot spot, which have distinct potential in rapid assessment and identification of pesticides on foods.