Fabrication and SERS enhancement study of composite materials based on MoS2 and gold/silver nano particles membrane structure modified AAO

Abstract

The aim of this study is to develop a composite substrate for surface-enhanced Raman scattering (SERS) applications by utilizing a PMMA inverted anodic aluminum oxide (AAO) nanostructure array, with a modified MoS₂ film as an interlayer between the gold nanofilm (Au film) and silver nanoparticles (AgNPs). The substrate not only possesses the electromagnetic enhancement mechanism (EM), but also introduces the chemical enhancement mechanism (CM) of MoS₂ and its Raman internal standard characteristics. Utilizing the properties of hyperbolic metamaterials (HMM) to support high-wave-vector body plasmon polaritons (BPP), with AgNPs as the external coupling structure, the large-wave-vector scattering light conducted within the nanostructured array resonator excites the BPP in the HMM, expanding the energy into the gap of the AgNPs. This energy further couples with the local surface plasmon polaritons (LSP) on the surface, generating a high-density “hotspot” on the surface. Through a novel reverse fabrication method, we successfully fabricated a three-dimensional (3D) arrayed nano-composite architecture and used it as a flexible SERS sensor, which can be easily applied to large-scale manufacturing. Finally, experimental verification demonstrated the excellent performance of this substrate. The limits of detection (LOD) for the probe molecules R6G and CV were found to be 6.93 × 10^-12 M and 5.16 × 10^-11 M, respectively. Additionally, in situ detection of CV on seafood surfaces resulted in a LOD of 3.78 × 10^-6 M. Therefore, we believe that this flexible composite material provides a feasible solution for high-sensitivity molecular detection and has promising applications in the field of biosensing.