Tunable plasmonic-lattice mode sensors with ultrahigh sensitivities and figure-of-merits

Abstract

We study the application of plasmonic lattice modes of arrays of closely packed large metallic nanodisks for chemical and biological sensors with ultrahigh sensitivity and refractive index dynamic range. Our results show that by changing the refractive index of the environment the narrow spectral features associated with these collective modes can be shifted by about 250 nm, going from visible (∼650 nm) to infrared (∼900 nm) range without any mode degradation. We attribute this shift to the refractive-index enhancement of the superstrate collective modes of these arrays. This index enhancement allows the arrays to preserve their mode integrity within this range. We show that, because of this feature and the ultra-long range fields of these modes, such structures can offer a unique platform for biosensors based on dielectric-coated metallic nanoparticle arrays. In such structures, the dielectric layers are used to tune the collective modes of the arrays, protect them against environmental degradation, and to prepare bio-functionalized surfaces for certain biological targets. We demonstrate that such a platform allows us to set the operation wavelength of these sensors within the visible-infrared spectral range with sensitivity more than 520 nm/refractive index unit and a figure of merit of about 17.

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“…232 Biological sensing based on the transition from LSPRs to SLRs was studied in arrays of gold nanoantennas covered by an ultrathin silicon layer by Gutha et al 233 They showed that SLRs may lead to very high sensitivities to small changes of refractive index; they did this by detecting biomonolayers and streptavidinconjugated semiconducting quantum dots. Sadeghi et al 234 investigated the application of SLRs of arrays of large metal nanodisks to chemical and biological sensing. They demonstrated that narrow SLRs could be shifted from the visible (∼650 nm) through to the infrared (∼900 nm) range by altering the environment's refractive index.…”

High-sensitivity plasmonic refractive index sensing using graphene

“…Even though the bulk FoM of our grapheneplasmon based sensor is large, it is not the largest achieved in the literature [23]. However, we emphasize that the main strength of our plasmon sensor is its ability to sense refractive index changes that occur very close to the surface.…”

Plasmonic Narrowband Filter Based on an Equilateral Triangular Resonator with a Silver Bar

“…Additionally, they found surface lattice resonances (SLRs) with high sensitivities to small changes of refractive index [10]. Sadeghi et al found that narrow SLRs could be shifted by changing the environmental refractive index based on the arrays of large nanodisks for chemical and biological sensing [11]. Additionally, plasmonic biosensing offers a new way to detect coronavirus with low-cost and rapid detection.…”