Surface enhanced Raman scattering of rhodamine B using silver nanowires
Silver nanowires (Ag NWs) were used as Surface-Enhanced Raman Spectroscopy (SERS) substrates to detect trace amounts of Rhodamine B (RhB) dye. Silver NWs formed by electroless deposition in ethylene glycol with the aid of polyvinyl pyrollidone (PVP) as capping agent were prepared in ethanol solution. Scanning electron microscopy (SEM) revealed that the Ag NWs have an average diameter and length of 103.7 nm and 41.1µm , respectively. The Ag NWs were used to enhance the Raman signature of RhB. Varying concentrations of RhB (1, 6, 10, 20 µM) were prepared. Ultraviolet-visible (UV-Vis) spectrophotometry showed that the dye has a peak absorbance at 553 nm. The absorbance measurements were used to calibrate the dye concentrations using the Beer-Lambert formula. Raman analysis showed that the Ag NWs enhance the intensity of the characteristic vibrational modes of RhB up to a factor of 6. The results show that RhB can be detected using Ag NW SERS substrates up to 1 µM. This work also demonstrates that Raman spectroscopy has great potential in analyzing chemical processes such as photodegradation aside from material identification.