Quantification of suppressed fluorescence in the Raman scattering of Rhodamine B deposited in Ag NW SERS substrates
The quenching of the fluorescence background that accompanies the surface-enhanced Raman scattering (SERS) of Rhodamine B was quantified using a least-squares baseline correction algorithm. Silver nanowires (Ag NWs) were prepared by electroless deposition in hot ethylene glycol in the presence of polyvinylpyrrolidone (PVP). The Ag NWs were deposited on a paper and were used as SERS substrates to detect Rhodamine B (RhB) in concentrations between 4 - 10 µM. The fluorescence of the 4 RhB concentrations was suppressed by 93.53-97.15% which is attributed to the non-radiative process of electron transfer from the RhB to the Ag NWs. The fluorescence suppression made the Raman signals observable. The Raman signals were enhanced by a factor of 104 due to the amplification of the laser and the localized surface plasmons of Ag NWs. The results confirm that Ag nanoparticles could be integrated in laser scanning microscopes for fluorescence suppression in Raman spectroscopy.