Prepare poly-dopamine coated graphene@silver nanohybrid for improved surface enhanced Raman scattering detection of dyes

- A novel ternary hybrid rGO-Ag wrapped by polydopamine (rGO-Ag@PDA) was prepared.
- RGO-Ag@PDA displays stronger adsorption ability to dyes than that of rGO-Ag.
- RGO-Ag@PDA shows much higher SERS activity than that of rGO-Ag.
- RGO-Ag@PDA also exhibits enhanced stability and improved reusability.
- Sensitive detection of aromatic dyes are achieved on rGO-Ag@PDA.

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 μM 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.

Reduced graphene oxide-silver nanoparticle wrapped by a thin layer of polydopamine (rGO-Ag@PDA) was prepared as a SERS substrate for aromatic dye detection. This novel substrate shows stronger absorption ability to dyes, higher SERS activity, increased stability and improved reusability than those of widely reported rGO-Ag hybrid substrate.160