Semiconductor-Noble Metal Composites for Synergistic SERS Sensing and In-situ Photocatalytic Degradation Monitoring of Novel Neonicotinoid-like Pesticides.

Photochemical removal of pollutants may generate more toxic intermediates, thus, identifying the degradation products of emerging contaminants is crucial for risk assessment. Flupyradifurone (FPF) is a novel butenolide insecticide highly effective against sucking pests, including those resistant to neonicotinoids. However, its widespread use has raised environmental and food safety concerns, while studies on its environmental fate remain limited. Leveraging SERS unique fingerprinting and in-situ monitoring properties, a novel semiconductor-noble metal composite ZnO@Ag/COF was synthesized. Endowed with synergistic SERS enhancement and photocatalytic degradation performance, this ternary system achieves pronounced synergistic effect, with its performance surpassing that of the binary counterpart in both SERS enhancement and photocatalytic degradation and "detection-degradation-monitoring" integration, thus enabling the first direct SERS detection and in-situ monitoring of FPF's photocatalytic degradation. Through material optimization, the material exhibited a high SERS enhancement factor of up to 4.35 × 106, with excellent reproducibility and stability. Furthermore, under simulated solar irradiation, an integrated platform coupling photocatalytic degradation and multi-mode monitoring was established. SERS, UV-Vis, fluorescence and HPLC-HRMS were applied to real-time monitor FPF's concentration changes and transformation pathways, track degradation intermediate evolution, and elucidate its dominant photocatalytic transformation mechanisms. This research not only fills the gap of Raman technology in detecting FPF, but also establishes a multifunctional platform integrating rapid detection, dynamic monitoring, and efficient degradation, demonstrating significant potential for environmental applications.