Superradiative plasmonic nanoantenna biosensors enable sensitive immunoassay using the naked eye

Abstract

A biosensor for simple and sensitive biomarker detection based on the strong light scattering (brightness) of superradiative plasmonic nanoantennas.

Atomically Smooth Single-Crystalline Platform for Low-Loss Plasmonic Nanocavities

“…By coupling optical fields with collective electronic excitations (i.e., surface plasmons), plasmonic nanoparticles have the ability to confine light down to a deep-subwavelength scale (e.g., 10 nm) and produce enhanced local electromagnetic fields. , However, it is challenging to achieve more tightly confined optical fields (e.g., sub-5 nm) . Recently, nanoparticle-on-mirror (NPoM) plasmonic nanocavities, , formed by placing a metal nanoparticle on a metal film separated with a nanometer-thick dielectric layer, have attracted intensive research interest due to their capability of extreme optical confinement and ease of fabrication. − They have given rise to a series of breakthroughs in state-of-the-art nanophotonic research and applications, − such as spontaneous emission enhancement, ,, strong coupling, ,, optical sensing, ,,, and quantum plasmonics. , Usually, the implementation of NPoM nanocavities uses deposited metal films as the mirror, − ,− ,− which have a polycrystalline structure and a typical surface root-mean-square (RMS) roughness of a few nanometers . Due to the extreme confinement of the optical fields in the nanometer-scale gap, granular polycrystalline metal films can introduce a significant optical loss because of the scattering of electrons by surface roughness and numerous grain boundaries. − This limits th...…”

“…3 Recently, nanoparticle-on-mirror (NPoM) plasmonic nanocavities, 4,5 formed by placing a metal nanoparticle on a metal film separated with a nanometer-thick dielectric layer, have attracted intensive research interest due to their capability of extreme optical confinement and ease of fabrication. 6−9 They have given rise to a series of breakthroughs in state-of-the-art nanophotonic research and applications, 10−29 such as spontaneous emission enhancement, 13,15,17 strong coupling, 16,18,25 optical sensing, 11,19,27,28 and quantum plasmonics. 20,21 Usually, the implementation of NPoM nanocavities uses deposited metal films as the mirror, 6−9,11−19,21−29 which have a polycrystalline structure and a typical surface root-mean-square (RMS) roughness of a few nanometers.…”

Refractometric Imaging and Biodetection Empowered by Nanophotonics

“…It has been widely pivoted as signal amplification in spectroscopic technologies like surface-enhanced Raman spectroscopy (SERS), [93] surfaceenhanced infrared absorption (SEIRA) spectroscopy, [94,95] and plasmon-enhanced fluorescence. [96,97] Significant breakthroughs have been achieved with single plasmonic nanosensors, such as sphere, [98] dimer, [99] and nanoparticle-in-mirror [100,101] by scattering imaging. Besides, these sensing units can be densely integrated on a chip, even in a large-scale arrayed form.…”

Design and Simulation of Broadband Horn Nanoantennas for Nanophotonic Applications

“…The first plasmonic nanostructures were used as optical nanostructures, and since then they have been widely used to redirect light scattering and emission, as they have excellent directional light scattering properties [20]. Among the numerous applications of nanoantennas in the literature, their integration in optical chip applications [23] and [24] stands out; wireless optical nanolink [25] and [26]; biosensors [27] and [28]; nanocircuits [29], [30]; anti-reflective coating [31], solar energy harvesting [32], at the same time spectral and spatial separation of light [33] and [34]; and hydrogen detection [35].…”