Few-layer MoS2-encapsulated Cu nanoparticle hybrids fabricated by two-step annealing process for surface enhanced Raman scattering

Here we designed a new kind of SERS substrate referred to as a MoS2-coated Cu nanopaticles (MoS2@CuNPs) substrate for R6G detection. The Cu nanoparticles wrapped by a thin MoS2 film were directly synthesized on flat quartz by two annealing process in a mixture of argon and hydrogen. Signals from a MoS2@CuNPs SERS substrate were also demonstrated to have interesting advantages over pure CuNPs SERS, in terms of the excellent linear relationship between Raman intensity and analyte concentration, strongly background fluorescence quenching and being more stable against photo-induced damage and oxidation. The minimum detectable concentrations of R6G on MoS2@CuNPs hybrids can be as low as 10−9 M which is one order lower than that on the pure CuNPs substrates. This synthetic approach is facile, scalable and applicable to the MoS2 film compound with other metals such as Ag, Au etc.