A multifunctional MoS2/Au/FP flexible SERS substrate: Construction with triple integration of signal amplification, self-calibration stability and photocatalytic self-cleaning

A high-performance flexible surface-enhanced Raman spectroscopy (SERS) substrate has been developed that integrates signal enhancement, self-calibration stability, and photocatalytic self-cleaning functions, enabling reliable SERS detection of organic pollutants in complex environments. The photocatalytically active MoS₂ serves as an intrinsic internal standard (IS) to effectively correct SERS signal fluctuations. The Schottky junction formed between MoS₂ and Au nanoparticles (Au NPs), through the synergistic effect of electromagnetic (EM) and chemical (CM) enhancements combined with localized electric field-induced electron flow, reduces the limit of detection (LOD) for Rhodamine 6G (R6G) to 3.24 × 10⁻⁹ M. Meanwhile, by enhancing the separation efficiency of photogenerated carriers, the substrate achieves efficient self-cleaning within 25 min, demonstrating excellent reusability. For practical application validation, the MoS₂/Au/filter paper (MoS₂/Au/FP) flexible substrate was successfully applied to the integrated “wiping, detection and self-cleaning” analysis of 10⁻⁵ to 10⁻⁷ M malachite green (MG) residues on herring surfaces. It maintained stable SERS quantitative performance across multiple rounds of real-sample analysis, verifying its signal reliability for complex matrix detection. This triple-integrated SERS substrate provides novel insights for developing efficient and reliable on-site rapid detection technologies, holding significant application value in food safety monitoring, environmental pollutant analysis, and related fields.