Fabrication of gold nanoparticle-coated paper and its use as a sensitive substrate for quantitative SERS analysis

This paper describes a rapid method for fabrication of a paper substrate coated with gold nanoparticles (GNPs) that results in the formation of a large number of hot spots on the surface and allows an adequate control of the active area. The resulting substrate is shown to be a viable material for use in quantitative surface-enhanced Raman spectroscopy (SERS) analysis. The influence of the amount of GNPs on the SERS signals (using crystal violet as a sample analyte) was correlated with field-emission scanning electron microscopy, UV-visible and theoretical studies. The use of this substrates results in larger enhancement of Raman signals and in comparably repeatability when compared to commercially available substrates. The substrate was applied to SERS-based determination of nicotine and uric acid in aqueous solution, and the respective limits of detection are 20 and 30 μg L⁻¹. The results indicate that the SERS substrates may be applied to the quantification of a wide variety of molecules. (author)