In situ synthesis of graphene oxide/gold nanocomposites as ultrasensitive surface-enhanced Raman scattering substrates for clenbuterol detection.

Abstract

A highly sensitive approach to detect trace amount of clenbuterol (CB) based on graphene oxide/gold nanoparticles (GO/Au NPs) by surface-enhanced Raman spectroscopy (SERS) was presented. To be specific, the GO/Au nanocomposites were formed by depositing Au NPs onto the surface of GO through an in situ reduction process, where a high density of inherent hot spots was created between Au NPs. By optimizing the depositing density of Au NPs, the strongest electromagnetic coupling effect originating from highly dense hot spots was obtained. The optimized GO/Au was demonstrated to enhance the Raman signals of CB by 4.8 times more than that of CB enhanced by Au NPs. Moreover, GO/Au nanocomposites exhibit good biocompatibility and accessible surface for high adsorption of target molecules through the pi-pi stacking with graphene oxide. Hence, the proposed GO/Au nanocomposites were utilized to capture aromatic molecules like CB and served as excellent sensitive SERS-active substrates for sensing of it, which exhibited an excellent linear performance in the range of 5 × 10-8 to 1 × 10-6 mol/L with a limit of detection (LOD) of 3.34 × 10-8 mol/L (S/N = 3). Due to high-density hot spots with easy operation, this proposed GO/Au nanocomposite-based SERS technique holds great potential in the application of food safety analysis and biomedical science.