Highly sensitive detection of Raman scattering to Rhodamine 6G dyes based on SERS for roughened plasmonic nanostructures

Abstract

The plasmonic nanostructures were prepared by an electrical exploding wire technique. The different morphology, surface roughness and hot spots of these nanostructures were examined by field emission scanning electron microscopy (FESEM), scanning transmission electron microscopy (STEM) and atomic force microscope (AFM). Surface enhanced Raman scattering (SERS) performance of the plasmonic nanostructures substrates were detected using Rhodamine 6G (R6G) dye as probe molecules. The surface enhanced Raman scattering SERS enhancement factor of R6G (1x10−6 M) reached (2.3X107) and (2.5X107) at the wave number (1650 cm−1) for the nanostructures AgNW@AgNPs and AgNW@PDA@AgNPs respectively. The plasmonic nanostructures AgNW@AgNPs and AgNW@PDA@AgNPs showed a good linear relationship with a value of the determination coefficient (R2=0.9717 and R2=0.9569) respectively between the intensities of SERS spectra and R6G dye concentration of characteristic spectral peaks (at 1650 cm−1). The nanostructures AgNW@AgNPs and AgNW@PDA@AgNPs have been exhibited a superb reproductions and excellent stability as a SERS substrate to realize the molecular detection. EEW technique has been not involved using of dangerous chemicals and pollutant organic solvents through the fabrication process. These advantages denoted that the substrates of nanostructures AgNW@AgNPs and AgNW@PDA@AgNPs could be considered as a good nominee for organic molecule detection under the very low concentration and used in ultra-sensitive devices and molecular detection through (SERS) applications in biological and chemical fields.