Rapid SERS detection of acid orange II and brilliant blue in food by using Fe3O4@Au core–shell substrate

With the widespread application of synthetic pigments in the food industry, food safety incidents caused by illegal addition of pigments have become more frequent. In this study, we synthesized core-shell nanomaterials for use in sensitive, fast, convenient, nondestructive detection and having good surface-enhanced Raman scattering (SERS) effect. The optimal synthetic conditions were selected to study semi-quantitative detection. Calculations for acid orange II and brilliant blue were done using density functional theory, and the characteristic peaks and vibration conditions for each pigment were identified. Acid orange II and brilliant blue in the food samples yellow croaker, braised pork, red pepper, green dumpling, and red wine were detected by SERS screening. Results were compared with those obtained by standard high-performance liquid chromatography method in order to verify the SERS method. The core-shell nanoparticles showed good performance in the rapid detection of pigments in food.