Self-Cleaning Surface-Enhanced Raman Spectroscopy Platform with Synergistic Electromagnetic and Charge Transfer Effects for Trace Detection and Photocatalytic Pesticide Degradation

Establishing an integrated platform capable of simultaneous trace-level pesticide monitoring and eco-friendly degradation is critical for preventing environmental pollution. Herein, a self-cleaning surface-enhanced Raman spectroscopy (SERS) platform is proposed by utilizing a ternary AgNPs-Fe₃O₄@TiO₂ nanocomposite with the localized surface plasmon resonance of Ag nanoparticles and photoresponsive properties of the heterogeneous structures, and the performance basis is described by detailed mechanism study. The possible mechanisms of the electromagnetic and charge transfer synergistic enhancement of the SERS effect and photodegradation were explored based on photon absorption and electron transfer in the ternary composites. The synergistic system achieves ultratrace pesticide quantification in fruits, with detection limits at 9.0 × 10⁻⁵ mg L⁻¹ for thiram and 9.2 × 10⁻⁶ mg L⁻¹ for chlorpyrifos. Furthermore, the platform exhibits postdetection self-cleaning capability, minimizing waste generation while ensuring reusability, demonstrating significant potential for agricultural pollutant monitoring.