Graphene oxide/Ag nanoparticle/WS ₂ nanosheet heterostructures for surface-enhanced Raman spectroscopy

Combing the merits of metals and semiconductors,with superior plasmon resonance effects and high charge mobility, 3D-nanocomposite structures consisting of graphene oxide (GO), noble metal nanostructures, and two-dimensional transition metal sulfides (2D-TMDS) are an important topic in surface-enhanced Raman scattering (SERS) research. This paper presents a novel GO/Ag NPs (silver nanoparticles)/WS ₂ composite SERS substrate, and electric field simulation by COMSOL software. The GO/Ag/WS ₂ composite substrate shows very high SERS detective sensitivity and stability to probe molecules such as rhodamine 6 g (R6G), crystal violet (CV), methylene blue (MB) and deoxyribonucleic acid (DNA). The SERS sensitivity can reach 10 ⁻¹² M, the relative standard deviation (RSD) is 8.24%, and the enhancement factor (EF) is approximately 6.60 × 10 ¹⁰ for R6G, which promoted the implementation of the SERS technique in the area of quantitative profiling and testing.