Surface-Enhanced Raman Spectroscopy Investigation of DNA Molecules on Gold/Epoxy Nanocomposite Substrates

Gold/epoxy nanocomposites were prepared by template-assisted solid-state dewetting and tested as a Surface-Enhanced Raman Scattering (SERS) substrates for DNA detection. The effect of excitation wavelength on the detected peak intensities was investigated with three different laser sources (532, 633, and 785 nm). The relationship between the plasmon absorbance band of the substrate and the excitation wavelength was studied. It was shown that the shift in the plasmon absorbance band, caused by the binding of the target-DNA molecules could have a major effect on the intensity of the measured peaks, which effect can be more significant than the signal contribution of target molecules on the surface.