The Twice-Oxidized Graphene Oxide/Gold Nanoparticles Composite SERS Substrate for Sensitive Detection of Clenbuterol Residues in Animal-Origin Food Samples

The illegal use of clenbuterol (CL), as a growth promoter in animal feeding, is banned in the majority of countries across the world, such as the European Union and China. In this study, a rapid and sensitive method for detecting CL in animal-origin food samples based on liquid-liquid extraction and surface-enhanced Raman spectroscopy (SERS) has been developed for the first time. A twice-oxidized graphene oxide/gold nanoparticles composite substrate was innovatively synthesized and used to enhance the characteristic Raman signal of CL at △v = 1474 cm and 1608 cm, and no more than 10 min of sample cleanup was required before SERS analysis. The optimized hybrid substrate demonstrated good stability over a period of 240 days, which is more stable than previous studies. Quantitation calculation was performed in the concentration range of 1–100 ng g with a limit of detection (LOD) as low as 1 ng g. Furthermore, the novel detection method was verified for use in the identification of real samples, and the results were consistent with those of liquid chromatography-tandem mass spectrometry (LC-MS/MS). The simplicity and reliability of the proposed method demonstrate its great potential for practical applications in the field of quality control and food safety.