Interlaced silver nanosheets grown on polyaniline coated carbon foam as efficient three dimensional surface enhanced Raman scattering substrate for molecule sensing

In this study, a new plasmonic hybrid AgNSs@PANI/3D-CF composed of interlaced silver nanosheets (AgNSs) grown on polyaniline (PANI) nanobars decorated three dimensional macroporous carbon foam (3D-CF) was prepared for molecule sensing by surface enhanced Raman scattering (SERS). The morphology, component, adsorption ability and SERS activity of the hybrid were characterized by SEM, EDS, FTIR, XRD, UV–vis absorption spectrum, and Raman spectroscopy. Controlling the silver growth time and introduction of succinic acid are vital to obtain the interlaced silver nanosheets fully covered 3D scaffold. The porous structure and large surface area of the hybrid bring it a high adsorption ability to dye molecules. And interlaced AgNSs endow the hybrid with dense hot-spots for highly efficient SERS detection. The lowest SERS detectable concentration of 4-mercaptobenzoic acid (4-MBA), Nile blue (NB) and Methylene blue (MB) on AgNSs@PANI/3D-CF was 0.1   nM, 0.1   nM and 10   nM, respectively. A good result was also achieved for NB detection in real water sample. The proposed hybrid with unique structure, high Raman enhancement ability and good reproducibility may find promising applications in environment monitoring, optical sensing and so on.