Metal-organic framework (MOF) MIL-101 and surface plasmon polariton (SPP) supported gold nanoparticles (Au NPs) hybrid systems were developed as a highly sensitive and reproducible surface-enhanced Raman scattering (SERS) detection platform, in which a green electrostatic self-assembly technology was adopted to construct the substrate. In an aqueous solution, the electronegativity of the particles can be used to prepare the composite substrate without any surface modifier. Due to the enrichment capacity of MIL-101 and the electromagnetic enhancement from Au NPs, the well-designed MIL-101/Au composites possessed ultrahigh sensitivity with the detection limit of Rhodamine 6G (R6G) as low as 10^-10 mol·L^-1. Meanwhile, the substrate exhibits high stability, excellent reproducibility, and recyclability. Additionally, the novel substrate can be explored for direct capture, and sensitively detect pesticide residues such as thiram.

A highly sensitive surface-enhanced Raman scattering (SERS) substrate was constructed, which was a Cu₂O-GO-AuNSts sandwich heterostructure assembled on a filter membrane, with ultrathin graphene oxide (GO) precisely embedded between the thorn-like Cu₂O microcrystals and gold nanostars (AuNSts). This heterostructure achieved strong electromagnetic enhancement and rapid photogenerated charge transfer by synergistically coupling broadband light absorption, efficient molecular enrichment, and abundant plasma "hotspots". Using rhodamine 6G (R6G) as probe molecules, the substrate achieved an ultra-low detection limit of 10^-13 mol·L^-1, demonstrating superior SERS sensitivity. More importantly, the heterostructure concurrently exhibited significant photocatalytic performance, thereby endowing the substrate with self-cleaning functionality. Even for the highly stable and recalcitrant persistent organic pollutant (POP), 2, 2′, 4, 4′-tetrabromodiphenyl ether (BDE-47), the characteristic SERS fingerprint could be clearly identified at a concentration as low as 10^-7 mol·L^-1. UV-Vis spectroscopy analysis revealed a degradation efficiency of approximately 66% after 20 h of light irradiation. The excellent SERS property of the sandwich structure originates from the synergistic effect of local surface plasmon resonance (LSPR) effect attributed to AuNSts and the molecular enrichment effect of GO lamellae and filter membrane, while the photocatalytic activity originates from the photo-induced charge transfer mechanism within the structure.