Graphene oxide wrapped Fe3O4@Au nanohybrid as SERS substrate for aromatic dye detection

An active surface-enhanced Raman scattering (SERS) substrate composed of graphene oxide (GO) wrapped gold nanoparticles (AuNPs) decorated-magnetic sphere Fe 3 O 4 (GO wrapped Fe 3 O 4 @Au hybrid) was prepared and used for aromatic dye detection. The hybrid was characterized by SEM, EDX, XRD, UV–visible spectroscopy and Raman spectroscopy. This hybrid showed high activity for SERS detection of aromatic dye due to the synergistic interaction among GO nanosheet, AuNPs and Fe 3 O 4 sphere. The dosages of AuNPs and GO were optimized to achieve a high sensitivity. The unique GO wrapped Fe 3 O 4 @Au hybrid has several advantages (such as high adsorption to target dye molecules, low noise response and high SERS enhancement ability) as SERS substrate over previously reported Fe 3 O 4 and AuNPs co-decorated GO sheet. Finally, the hybrid was successfully used for SERS detection of aromatic dye pollutant malachite green (MG) and nile blue A (NBA) even at concentration down to 1   nM and 0.1   nM, respectively. Potential of this substrate for multiplex detection of dye mixture (MG and NBA), and practical detection of MG in real sample were also evaluated. Our results suggested that the hybrid of GO wrapped Fe 3 O 4 @Au can be used as an efficient SERS platform for aromatic dye detection.