| CPC G01N 21/658 (2013.01) [B05D 5/00 (2013.01); B05D 7/24 (2013.01)] | 15 Claims |
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1. A method of increasing a surface-enhanced Raman scattering (SERS) signal of a compound, comprising:
forming a monolayer assembly on a first substrate by:
dropping a 200-400 μL aliquot of a colloid of gold nanoparticles
onto the first substrate to form a film;
placing a second substrate onto the film, wherein the colloid is disposed between the first and second substrates and the first and second substrates are spaced 0.1-2 mm apart;
irradiating the colloid disposed between the first and second substrates with infrared light to evaporate the solvent to form the monolayer assembly of gold nanoparticles, wherein the monolayer assembly of gold nanoparticles includes a plurality of strips of gold nanoparticles spaced 25 μm apart;
dissolving the compound in water to form a solution;
adding the first substrate at least partially coated with the gold nanoparticles to the solution to form a mixture;
wherein the gold nanoparticles are in a monolayer assembly on the substrate;
wherein the gold nanoparticles are 10-250 nm in size;
wherein a surface of the gold nanoparticles is not functionalized with an outer shell;
wherein the monolayer assembly does not require a surfactant or linker;
removing the first substrate from the mixture and washing with water to form a SERS sample having at least a portion of molecules of the compound adsorbed to the gold nanoparticles on the first substrate; and
recording a SERS spectrum of the SERS sample;
wherein the SERS signal of the SERS spectrum is higher than a SERS signal of a SERS spectrum of the compound on a different substrate without the gold nanoparticles.
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