▎ 摘　　要

A novel hybrid of reduced graphene oxide -silver nanoparticle composite (rGO-Ag) wrapped by a thin layer of polydopamine (PDA) (rGO-Ag@PDA) was prepared as a highly active substrate for surface enhanced Raman scattering detection of aromatic dyes. rGO-Ag prepared by one -pot citrate reduction was coated with PDA through the self -polymerization of dopamine to produce the rGO-Ag@PDA hybrid. The morphology, component, absorption ability and SERS activity of the products were characterized by SEM, EDS, FTIR, UV-vis absorption, and Raman spectroscopy. Due to the PDA coating, the rGO-Ag@PDA hybrid shows enhanced adsorption ability to the dye molecules, and subsequently leads to stronger SERS signal of dyes than that obtained on widely reported rGO-Ag hybrid substrate. SERS detection of crystal violet, methylene blue, and malachite green on the rGO-Ag@PDA can be down to 0.1 nM, 0.1 p.M and 1 nM, respectively. Moreover, the rGO-Ag@PDA also displayed enhanced stability and improved recyclability than those of rGO-Ag. The proposed substrate may be used for SERS analysis and environmental monitoring. (C) 2016 Elsevier B.V. All rights reserved.