Giant and uniform fluorescence enhancement over large areas using plasmonic nanodots in 3D resonant cavity nanoantenna by nanoimprinting

Using a new nanoplasmonic architecture and an optimized spacer, we observed the following: (a) the average fluorescence of an infrared dye (indocyanine green) is enhanced by2970 fold uniformly (variation < 11%) over a large sample area and over a wide range of dye concentrations (380 to 380000moleculeνm ²), laser excitation powers and laser beam sizes; and (b) for a single molecule placed at a hot spot, the fluorescence enhancement is 4.5×10 ⁶ fold. The giant and uniform enhancements (orders of magnitude higher than before), plus easy and inexpensive large area fabrication (>4 wafers), should open up wide applications.