Plasmon-enhanced fluorometry based on gold nanostructure arrays. Method and device

In this work, we describe a method of surface-enhanced fluorometry, based on the phenomenon of localized surface plasmon resonance in unordered gold nanostructure arrays. The theoretical approach for the model system gold nanoparticle-dielectric spacer in the electrostatic approximation by solution of Laplace's equation is considered. The developed technology for manufacturing the plasmonic substrates as well as design of the novel laser-based compact fluorometer are presented. The arrays of gold nanostructures on solid substrates (nanochips) coated with different thicknesses of SiO2 were developed and fabricated by thermal annealing of gold island films with subsequent dielectric spacer deposition. As an example for verification of the proposed method, the fluorescence properties of the system gold nanostructures array - SiO2 dielectric coating - Rhodamine 6G were studied. It has been shown that enhancement of dye emission up to 22 times for dielectric coating with the thickness of about 20 nm is possible. Presented method is of importance for the development of the novel nanoscale sensors, biomolecular assays and nanoplasmonic devices.