Monolayer ZnS@Ag Nanospheres SERS Substrate for Highly Sensitive Dye Molecules Detection

Surface-enhanced Raman scattering (SERS) substrates with low cost, high sensitivity and good reproducibility are still challenging in practical application. Herein, we propose a facile method to prepare monolayer ZnS@Ag nanospheres (NSs) by sputtering Ag nanoparticles (NPs) on the surfaces of the monolayer ZnS NSs produced by self-assembly. The monolayer ZnS@Ag NSs have rough surface and nanoscale gaps, which can produce large SERS effect. The dye molecules, Rhodamine 6G (R6G) and Rhodamine B (RhB), were used as probe to evaluate the SERS performance on the monolayer ZnS@Ag NSs. It was found that the monolayer ZnS@Ag NSs showed the high SERS sensitivity in the detection of R6G and RhB, the limit of detection (LOD) down to 9.12×10⁻¹³ M and 8.55×10⁻¹¹ M, respectively. The corresponding enhancement factors (EF) are 3.01×10⁸ and 8.2×10⁶, respectively. Furthermore, the ordered structure makes the monolayer ZnS@Ag NSs substrate with high signal reproducibility and stability, and the relative standard deviation (RSD) values are less than 15%. Therefore, the monolayer ZnS@Ag NSs is a candidate for detecting organic dyes in the environment.