Preparation of a high‐performance thermally shrinkable polystyrene SERS substrate via Au@Ag nanorods self‐assembled to detect pesticide residues

Abstract

This paper reports a “bottom‐up” substrate preparation method using a two‐phase interface self‐assembly technology that combines silver‐coated gold core–shell nanorods with the thermally shrinkable polystyrene (TSP) support material for surface‐enhanced Raman spectroscopy (SERS), that is, TSP‐SERS substrate. The gold nanorods with long absorption wavelength were used as the core, and the silver shells were coated to obtain the core–shell nanostructures with a stronger resonance with the wavelength of the light source. The density of the nanostructures and numbers of “hot spots” within the light spot increased via the three‐dimensional folding feature formed by thermal shrinkage. The combined effect of the two factors increases the enhancement factor by an order of magnitude to 107 after thermal contraction. The detection concentration of 4‐mercaptobenzoic acid can reach 10−9 M, and the maximum relative standard deviation is only 8.9%. In fact, the detection limit of benzimidazole on the surface of apple can reach 0.5 mg/L, and the recovery deviation is controlled within the range of 11.7%. The practical detection of benzimidazole pesticide residues showed that this method has wide application prospects in the detection of pesticide residues.

Contractible Plasmonic Nanospheres Array with Dynamically Tailorable Gap Size for Molecule Trapping and Sensitive SERS Detection

“…In addition, the significant increase in SERS intensity at the beginning is attributed to a decrease in gap size, providing an opportunity for in situ monitoring of changes in interparticle spacing. Moreover, as shown in Table S3 (Supporting Information), the heating temperature and duration required by our method are significantly lower than those required by comparable methods in the literature, [ 30,31,47,48 ] demonstrating the superiority of this method.…”

Plasmonic 3-D wrinkled polymeric shrink film-based SERS substrates for pesticide detection on real-world surfaces

“…Whereas, the previously reported wrinkled film substrate demonstrated sensing of 4-mercaptobenzoic acid up to 10 −9 M concentration resulting in a maximum enhancement factor of the order of 10 7 . 42 Another report by Zhang, L., et al , demonstrated that using a wrinkled nanoporous gold film polymer substrate enabled the sensing of crystal violet and rhodamine-6-G up to 10 −8 M and 10 −11 M concentrations, respectively, with a highest calculated local enhancement factor of ∼10 9 . 17 Thus, the present Au bead@Ag nanorod based shrink film substrate showed a better LOD of 10 −13 M with BDT as the model analyte.…”

Recent advances in linear and nonlinear Raman spectroscopy. Part XIV

“…Zhang et al [ 49 ] described a rapid determination of trace nitrofurantoin in cosmetics by SERS using a nanoarrayed hydroxyl polystyrene‐based substrate. Zhao et al [ 50 ] described the preparation of a high‐performance thermally shrinkable polystyrene SERS substrate via self‐assembled Au@Ag nanorods to detect pesticide residues. They showed by practical detection of benzimidazole pesticide residues that this method has wide applicability for the detection of pesticides.…”