Facile preparation of Ag NPs@NiO foam as a prominent SERS substrate for sensitive detection of food pigments in beverages

Excessive food pigments can be harmful to human health and in severe cases can cause cancer. Unlike conventional and time-consuming detection techniques, surface enhanced Raman scattering (SERS) is a fast, sensitive and accurate method. Ag NPs@NiO foam is developed as an efficient SERS substrate, featuring a large specific surface area and suitable charge transfer pathways. R6G can be detected at a concentration as low as 10 −14 M with an analytical enhancement factor (AEF) as high as 1.682 × 10 12 , demonstrating the high sensitivity of Ag NPs@NiO foam. In practical applications, Ag NPs@NiO foam is successfully used for the detection of food blue, amaranth, allura red in beverages, with the limit of detection lower than the safety limits in China. This facile and highly sensitive substrate provides a solid foundation for fast and accurate food analysis.