In surface-enhanced Raman scattering (SERS), flexible substrate plays an important role in target molecular collection from various shape surfaces and increases the analytical sensitivity. In this study, silver nanoparticles (Ag NPs) were deposited on a non-woven fabric used as an SERS substrate by self-assembly, in situ growing or the self-assembly/in situ growing combination method. 4-Aminothiophenol was selected as a model molecular for the evaluation of the SERS performance using the substrates. The Ag NPs substrate prepared by self-assembly/ in situ growing method presented the best Raman enhancement effect and its enhancement factor was estimated as high as 3.5 9 10 6 . The substrate was applied to the determination of four pesticide residues on the surfaces of fruit samples through wipe sampling, and the results revealed the good reproducibility of SERS responses and high detection sensitivity. The prepared flexible substrate was simple to fabricate and environmentally friendly. It could be expected to be a useful tool in rapid on-site test of pesticide residues on fruit surfaces because of its high sensitivity, convenience and non-destructive characteristics.

An arginine-modified reduced graphene oxide composite was prepared in an on-line solid-phase extraction disk and coupled to high-performance liquid chromatography for the re-enrichment of heterocyclic aromatic amines. The synthetic composite presented an excellent adsorption capability because of the ultrahigh active surface area of graphene and the abundant alkaline groups of arginine. The adsorption capacity of it was 52.7 mg 2-amino-3-methyl-imidazo[4,5-f]-quinoline per gram, nearly twice that of threonine-modified reduced graphene oxide composite, glutamic acid modified reduced graphene oxide composite, and reduced graphene oxide. This on-line method was successfully applied to the detection of a series of heterocyclic aromatic amines in beef jerky. After clean-up and re-enrichment of the on-line solid-phase extraction disk, the chromatographic background of the sample was low and the shape of chromatographic peaks was sharp. The method detection limit was in the range of 0.30-0.49 ng/g, and the recovery was in the range of 82.0-111.5%.

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Surface‐enhanced Raman scattering (SERS) greatly expands the applications of Raman spectroscopy and is a promising technique for food safety, environmental analysis, and public safety. Thin‐film microextraction (TFME) provides an efficient sample preparation method for SERS to improve its selectivity and detection efficiency. This review comprehensively describes the development and applications of SERS and TFME, including the history, mechanisim, and active substrate of SERS and the theory, device, forms, and practical applications of TFME. The applications of TFME‐SERS in food safety and environment monitoring are discussed, which could improve their advantages. TFME extracts and enriches the target analytes to eliminate the interfering substance, providing a facial way for SERS to analyze the target analytes in complex matrices. The development of TFME‐SERS technology not only expands the application range of TFME, but greatly improves the anti‐interference ability and detection sensitivity of SERS. Thus, the established methods are fast, convenient, and highly sensitive. This technology is potential to be applied in the on‐site and real‐time detection.