Controlled-layer and large-area MoS₂ films encapsulated Au nanoparticle hybrids for SERS

In this work, a facile and effective method for controlled-layer and large-area MoS₂ films encapsulated Au nanoparticle hybrids is developed. With accurate Ar plasma treatment time control, the large-area MoS₂ layers can be obtained from monolayer to trilayer. The fabricated MoS₂@Au NPs with higher surface area exhibit excellent Raman enhanced effect for aromatic organic molecules (rhodamine 6G and crystal violet) and achieve the best when the monolayer MoS₂@AuNPs was obtained. The limit of detection is found to be as low as 1 × 10^-10 M. The MoS₂@AuNPs was characterized by SEM, EDS, AFM, Raman spectroscopy, UV-Vis, XRD and HRTEM.