Recyclable SERS Substrate with Coral-like Nano Ag/ZnO Structure Based on Cotton Fabric Used for In-situ Detection of Pesticides

A novel recyclable flexible SERS substrate with a hierarchical structure was fabricated by growing ZnO nanorods (ZnO NRs) on three-dimensional (3D) ordered cotton fabrics through a chemical hydrothermal method and depositing Ag nanoparticles (Ag NPs) on coral-like ZnO NRs. The Ag/ZnO/cotton fabrics (AZCF) exhibit superior SERS signals with a detection limit of 4-aminothiophenol (PATP) down to 10−10 M and an excellent uniformity (relative standard deviation lowered to less than 20 %). It also can achieve photocatalytic degradation of different substances, such as rhodamine 6G (R6 G), PATP and thiram. Furthermore, this SERS substrate was successfully applied to the in-situ detection of thiram on the surface of apple, and the detection limit is low to 5 mg/kg. Therefore, our studies not only constructed a promising SERS substrate with super sensitivity, good reproducibility and excellent stability for molecular detection, but also suggest a potential method for the actually in-situ detection of pesticide residues.