Biological sensing using hybridization phase of plasmonic resonances with photonic lattice modes in arrays of gold nanoantennas

Abstract

We study biological sensing using the hybridization phase of localized surface plasmon resonances (LSPRs) with diffraction modes (photonic lattice modes) in arrays of gold nanoantennas. We map the degree of the hybridization process using an embedding dielectric material (Si), identifying the critical thicknesses wherein the optical responses of the arrays are mainly governed by pure LSPRs (insignificant hybridization), Fano-type coupling of LSPRs with diffraction orders (hybridization state), and their intermediate state (hybridization phase). The results show that hybridization phase can occur with slight change in the refractive index (RI), leading to sudden reduction of the linewidth of the main spectral feature of the arrays by about one order of magnitude while it is shifted nearly 140 nm. These processes, which offer significant improvement in RI sensitivity and figure of merit, are utilized to detect monolayers of biological molecules and streptavidin-conjugated semiconductor quantum dots with sensitivities far higher than pure LSPRs. We further explore how these sensors can be used based on the uncoupled LSPRs by changing the polarization of the incident light.

Pedestal formation of all-semiconductor gratings through GaSb oxidation for mid-IR plasmonics

“…1 shows that the oxidation process is repeatable and we focus the discussion in the following on the grating with smaller ribbon width. Qualitatively the blue-shift can be understood by considering the excitation condition for localized surface plasmons [7,[29][30][31]. In the x-y-plane, see inset in Fig.…”

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

“…Guatha et al detected biomonolayers and streptavidin-conjugated semiconducting quantum dots by employing the arrays of gold nanoantennas covered by an ultrathin silicon layer. 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].…”

Coherent Networks of Si Nanocrystals: Tunable Collective Resonances with Narrow Spectral Widths

“…[ 9–16 ] The characteristic features of SLRs, including their narrow linewidths, have made them appealing hosts for various applications, including excitonic laser systems, [ 17–19 ] optical filters, [ 20 ] control of the emission of quantum emitters, [ 17,19 ] and biological and chemical sensing. [ 21–23 ]…”