GO/Au@Ag nanobones decorated membrane for simultaneous enrichment and on-site SERS detection of colorants in beverages

Abstract

In this paper, we have developed a graphene oxide/Au@Ag nanobones membrane (GO/Au@Ag NBs membrane) for simultaneous enrichment and SERS detection of colorants in beverages. Raman enhancement effect of Au@Ag nanobones (NBs) and enrichment capability of graphene oxide (GO) are contributed to the high sensitivity of GO/Au@Ag NBs membrane. Microporous membrane provides a support template for uniformly loading high-density GO/Au@Ag NBs. When beverage flow through the portable filtration unit with GO/Au@Ag NBs membrane, colorant molecules could be efficiently enriched. The prepared GO/Au@Ag NBs membrane exhibits an excellent sensitivity with a LOD of Rhodamine 6 G at 1.12 × 10−9 mol/L, and has good performances of uniformity (with an RSD of 7.87 %), repeatability (with an RSD of 10.44 %), time stability (stored up to 60 days). Six types of colorants were sensitively detected combined with GO/Au@Ag NBs membranes, portable filtration unit and self-development portable Raman system. The lowest distinguished amounts of molecular accumulation are well below the maximum usage limits and the limits of visual recognition. Support vector machine model was established to identify the types of colorants, including colorants with coincident Raman peaks or similar visual colors, with an average accuracy of 94.8 %. In addition, GO/Au@Ag NBs membranes were used to enrich and detect colorant additives in commercial beverages, brilliant blue in energy beverage and carmine in bayberry wine were successfully detected. These results indicate GO/Au@Ag NBs membranes combined with a portable filtration unit can effectively enrich and rapidly detect colorants in beverages, and has great potential in the field of on-site and sensitive food safety detection.