Regenerated SERS substrate based on Ag/AuNPs-TiO 2 -oxidized carbon cloth for detection of imidacloprid.

Imidacloprid (IMI) are widely used in modern tea industry for pest control, but IMI residues pose a great threat to human health. Herein, we propose a regeneration metal-semiconductor SERS substrate for IMI detection. We fabricated the SERS sensor through the in-situ growth of a nano-heterostructure incorporating a semiconductor (TiO ₂ ) and plasmonic metals (Au, Ag) on oxidized carbon cloth (OCC). Leveraging the high-density hot spots, the formed Ag/AuNPs-TiO ₂ -OCC substrate exhibits higher enhancement factors (1.92 × 10 ⁸ ) and uniformity (RSD = 7.68%). As for the detection of IMI on the substrate, the limit of detection was lowered to 4.1 × 10 ^-6  μg/mL. With a hydrophobic structure, the Ag/AuNPs-TiO ₂ -OCC possessed excellent self-cleaning performance addressing the limitation of single-use associated with traditional SERS substrates, as well as the degradation capability of the substrate under ultraviolet (UV) light. Accordingly, Ag/AuNPs-TiO ₂ -OCC showcases outstanding SERS sensing and regenerating properties, making it poised for extensive application in the field of food safety assurance.
Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper.
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