Synergistic SERS enhancement of NiCo-LDHs microurchins and silver nanoparticles for ultra-sensitive and reusable detection of thiabendazole

Abstract

Two-dimensional layered semiconductor materials as a distinctive class of materials are comprehensively explored for widespread applications due to narrow bandgap, controllable morphology, and tunable metal cation composition. Herein, we constructed a sensing platform of surface enhanced Raman spectroscopy (SERS) by combination of nickel‑cobalt layered double hydroxide (NiCo-LDH) microurchins and plasmonic silver nanoparticles (Ag NPs) for fungicide detection of thiabendazole (TBZ). The NiCo-LDHs/Ag-NPs microcomposites consist of NiCo-LDHs microurchins having a large number of nanoneedles deposited with photoreduced Ag NPs. The SERS platform with NiCo-LDHs/Ag-NPs shows an excellent SERS performance for TBZ detection, including an ultra-low detection limit of 1.49 × 10−11 M, a sublime enhancement factor of 1.71 × 109, high uniformity, good reproducibility, and long-term storage stability. The ultrahigh SERS activity of NiCo-LDH/Ag-NPs can be attributed to strong electromagnetic enhancement in the nanoscale gaps between Ag NPs, massive charge transfer through large-area NiCo-LDH/Ag-NPs interfaces, and the synergistic action of electromagnetic and charge transfer mechanisms. Besides, the unique morphology of NiCo-LDHs/Ag-NPs microcomposite provides a broad surface area for adsorption of TBZ molecules for further Raman signal enhancement. The practicability of the proposed SERS platform is confirmed by detecting TBZ in the real samples of apple juice and river water. The exceptional self-cleaning capability of the NiCo-LDHs/Ag-NPs microcomposite with an retention rate of 81.97 % even after the fifth degradation cycle underscores its impressive sustainable reusability and cost-effectiveness. The findings in this work lay the foundation for the development of high-performance SERS platforms to ensure food safety and environmental protection.