SERS-Based Plasmon-Driven Reaction and Molecule Detection on a Single Ag@MoS₂ Microsphere: Effect of Thickness and Crystallinity of MoS₂

Plasmon-driven catalysis on a single particle has attracted great attention in recent years, while the relationship between reaction efficiency and substrate remains to be deeply studied. Here, we demonstrate the fabrication of a novel Ag@MoS₂ core-shell single particle SERS substrate by coating MoS₂ film on Ag microspheres through the pulsed laser deposition (PLD) technique, where the thickness and crystallinity of MoS₂ can be effectively controlled by the PLD time and temperature. It is revealed that both the thickness and crystallinity of MoS₂ can greatly influence the hot electron transfer process, and thus the plasmon-driven reaction (4-NTP into DMAB) efficiency and Raman enhancement of dye molecules on Ag@MoS₂ substrates. Generally, high crystallinity and thin thickness of MoS₂ can lead to accelerated plasmon-driven reaction efficiency and greatly enhanced Raman signals of target molecules. This study opens up a new avenue for broadening the research area of the plasmon-driven catalysis and Raman enhancement on the hybrid system of two-dimensional materials and metal nanostructures.