The Effect of the Buffers’ Refractive Index on the SERS Signal of Rhodamine 6G (R6G)

Abstract

surface-enhanced Raman spectroscopy (SERS) is adopted in a microfluidic cell to detect Rhodamine 6G (R6G) dye molecules using a gold nanoparticle Au NP’s –epoxy surface nanocomposite as surface-enhanced Raman spectroscopy substrates. We studied the effect of changing the environment’s refractive index RI at the nanocomposites’ surface by using a solution of 10-4 M of Rhodamine 6G (R6G) dye in different water + ethylene glycol (EG) mixtures with ethylene glycol concentrations ranging from 25-100%. The surface-enhanced Raman spectroscopy (SERS) measurement was performed with 633nm excitation wavelengths. The surface-enhanced Raman spectroscopy spectra (SERS) of the Rhodamine 6G (R6G) molecule obtained in the microfluidic system show reproducibility with high sensitivity. The effect of the measurement buffer’s refractive index RI is visible as the intensity of the characteristic Raman peaks changes.