▎ 摘　　要

An active surface-enhanced Raman scattering (SERS) substrate composed of graphene oxide (GO) wrapped gold nanoparticles (AuNPs) decorated-magnetic sphere Fe3O4 (GO wrapped Fe3O4@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 Fe3O4 sphere. The dosages of AuNPs and GO were optimized to achieve a high sensitivity. The unique GO wrapped Fe3O4@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 Fe3O4 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 Fe3O4@Au can be used as an efficient SERS platform for aromatic dye detection. (C) 2015 Elsevier B.V. All rights reserved.