La,S-CeO(2)/Ag-based reusable SERS substrate for simultaneous detection of multiple hazardous molecules.

This study presents a three-dimensional, bowtie-like La, S co-modified CeO/Ag composite as a high-performance, reusable surface-enhanced Raman scattering (SERS) substrate. The substrate demonstrates exceptional sensitivity for Congo red (CR) with a low detection limit of 10 M, an enhancement factor of 4.3 × 10, and a wide linear response R = 0.997. It also exhibits excellent reproducibility RSD = 3.25% and remarkable long-term stability, retaining ∼90% of its initial SERS activity after three months. The superior performance is attributed to a synergistic enhancement mechanism, where the unique architecture provides dense electromagnetic hot spots, and the La-S co-modification optimizes the electronic structure to facilitate efficient charge transfer. Its practical utility is demonstrated through the detection of various pollutants, such as tetracycline (10 M) and thiram, even in spiked lake water (10 M). Significantly, the integrated photocatalytic self-cleaning function endows the platform with excellent reusability, with the SERS signal for CR and thiram retaining ∼83% and ∼76% respectively after five detection-degradation cycles. This work provides an effective strategy for developing multifunctional, reusable SERS substrates through structural and compositional engineering, showcasing great potential for applications in environmental monitoring and analytical science.