Construction of Fe 3 O 4 /PDA/Ag Nanoparticles and Coupling with SERS for Detection of Pesticide Residue

Abstract Carbendazim and thiophanate-methyl are highly toxic persistent organic pollutant. Prolonged exposure to them may bring a wide variety of disease. For this, a facile and high sensitive approach (surface-enhanced Raman scattering: SERS) with nanocomposite (Fe₃O₄/PDA/Ag) as substrates was developed for detection of carbendazim and thiophanate-methyl. The core of Fe₃O₄ nanoparticles (NPs) were synthesized by coprecipitation method, and it was coated with polydopamine (PDA). Ag NPs was obtained by chemical reduction-oxidation. The three-layer structure of magnetic composite nanomaterial with noble metal, namely Fe₃O₄/PDA/Ag was fabricated via the interaction between Ag and the amino groups of PDA. The prepared Fe₃O₄/PDA/Ag composites was characterized by XRD, UV-VIS, IR and VSM. The Fe₃O₄/PDA/Ag as SERS substrates was employed to detect carbendazim and thiophanate-methyl by Raman technology. It was demonstrated that the number of Raman peaks were obvious increased, and intensity for carbendazim and thiophanate-methyl were significantly enhanced due to the substrate of Fe₃O₄/GO/Ag. A new substrate for SERS was designed with the detection signal significant amplification. New approach for high sensitive, rapid and facile detection of pesticide residues was developed in the study.