1 research outputs found
SERS Sensing Using Graphene-Covered Silver Nanoparticles and Metamaterials for the Detection of Thiram in Soil
Multilayer
hyperbolic metamaterial (HMM)-based SERS substrates
have received special consideration because they accommodate various
propagation modes such as surface plasmonic polaritons (SPP). However,
the SPP modes are difficult to generate in HMM due to their weak electric
field enhancement. In this article, we designed novel SERS substrates
consisting of graphene-covered AgNPs and HMM. The graphene-covered
AgNPs work as an external coupling structure for hyperbolic metamaterials
due to this structure exhibiting significant plasmonic effects as
well as unique optical features. The localized surface plasmonic resonance
(LSPR) of the graphene-covered AgNPs excited the SPP and thus formed
a strong hot spot zone in the nanogap area of the graphene. The Raman
experiment was performed using rhodamine 6G (R6G) and crystal violet
(CV), which showed high stability and a maximum enhancement factor
of 2.12 × 108. The COMSOL simulation further clarified
that enhanced SERS performance was due to the presence of monolayer
graphene and provided an atomically flat surface for organic molecules
in a more controllable manner. Interestingly, the proposed SERS structure
carries out quantitative detection of thiram in soil and can satisfy
the basic environmental need for pesticide residue in the soil