Plasmonic antennas enable monitoring biochemical reactions in nanometer-sized volumes with high fluorescence brightness. Among the antenna designs, the double nanohole (DNH) is attracting much interest thanks to its distinctive advantages of narrow gaps, high enhancement and efficient background screening.
In a Scientific Reports paper “Nanoscale volume confinement and fluorescence enhancement with double nanohole aperture”, we completely characterize the fluorescence emission in a DNH antenna, and realize a volume reduction of 7000-fold as compared to diffraction-limited confocal microscopes together with single molecule fluorescence enhancement up to 100-fold and 30-fold LDOS enhancement.
The DNH is an efficient design to reach nanometer confinement of light, with comparatively simpler nanofabrication as compared to other designs. The high optical performance and the robust design open promising perspectives to study complex biochemical dynamics at micromolar physiological concentrations.