A novel AuNRs self-assembly dimer-based aptasensor for ultrasensitive SERS sensing of wheat gluten

Ultra-sensitive, accurate, and quantitative detection of wheat gluten in food products can provide a basis for correct labeling “gluten-free” on food packages. In this strategy, a gold nanorods (AuNRs) self-assembly dimer-based surface-enhanced Raman scattering (SERS) sensor was constructed to achieve ultra-sensitive and accurate SERS quantification of wheat gluten. The AuNR dimers based-SERS sensor demonstrated satisfactory specificity, accuracy, reproducibility, and storage stability (35 days at 4°C). Benefitting from the signal amplification function of AuNR dimers and the superiority of SERS, the sensor exhibited a wide detection range from 0.1-20 μg/mL with a limit of detection (LOD) of 35.06 ng/mL (S/N=3) and a limit of quantitation (LOQ) of 116.87 ng/mL (S/N=10). This strategy successfully achieved accurate quantification of gluten in 17 kinds of food products from five categories of commercially processed foods, providing new opportunities for ultra-sensitive and accurate quantification of gluten in food products throughout the supply chain.