An integrated enrichment-enhancement membrane SERS substrate for rapid detection of polycyclic aromatic hydrocarbons in aquatic environments.

This paper proposes an integrated dual-functional membrane SERS substrate Ag-hydroxypropyl-β-cyclodextrin/rGO/nanocellulose (Ag-HP-β-CD/rGO/NCF), for the rapid simultaneous enrichment and detection of polycyclic aromatic hydrocarbons (PAHs) in aquatic environments. This composite membrane SERS substrate achieves high SERS activity through the synergistic electromagnetic and chemical enhancement of hybridized Ag-HP-β-CD nanoparticles and rGO nanosheets. The Ag-HP-β-CD/rGO hybrid structure is then firmly anchored within a robust three-dimensional NCF framework, ensuring structural stability and signal uniformity. Furthermore, by combining the integrated membrane SERS substrate with a filtration device, target PAHs can be efficiently captured and enriched, leveraging the affinity interactions of HP-β-CD and the enrichment effect of delocalized π-electron system of rGO nanosheets, without complicated pretreatment of PAHs in water. Moreover, the performance of the SERS substrate is evaluated using pyrene as a probe molecule, demonstrating excellent uniformity (RSD 5.63 %), reproducibility (RSD 6.62 %) and time stability (RSD 4.81 % @ 10 min). Only one filtration is required to effectively enrich typical PAHs in aquatic environments, pyrene and fluoranthene, with detection limits as low as 9.89 μg/L and 11.21 μg/L respectively, and the entire enrichment and detection process can be completed within 15 min. The high-efficiency SERS platform promises on-site monitoring of persistent organic pollutants in aquatic environments.