Dielectric nanocavity-coupled surface lattice resonances for high-efficiency plasmonic sensing

Abstract

Surface lattice resonances (SLRs) arising in metal nanostructure arrays have shown tremendous application prospects in the field of plasmonic biosensing. However, these SLRs still suffer from poor optical properties, such as broad linewidth or weak resonance intensity that is especially excited under normal incidence and asymmetric environments, which hinder further practical applications. Herein, we theoretically propose an effective strategy to tailor the SLRs performance of metal nanostructure arrays by introducing a dielectric nanocavity. Originating from the strong interference between the in-plane lattice resonance mode and plasmonic gap cavity modes, the dielectric nanocavity-mediated gold nanostructure arrays exhibit both narrow spectral features with a linewidth of ∼8.2 nm and strong resonance intensity with absorbance amplitude exceeding 95%, even though under normal incidence and asymmetric environment excitation. The simulation results then show that the sensitivity and the figure of merit can reach up to 527.5 nm RIU−1 and 64.3, respectively, as for plasmonic refractive index sensing. This work not only paves the way toward the achievement of effective control of in-plane SLRs, but also provides a potentially attractive candidate for the development of high-efficiency plasmonic sensors.

High Q-Factor, High Contrast, and Multi-Band Optical Sensor Based on Plasmonic Square Bracket Dimer Metasurface

“…For example, M. Saad Bin-Alam et al reported a plasmonic metasurface with a Q-factor of 2340 [ 25 ], which has been the highest experimental measurement value so far. Hu et al proposed dielectric nanocavity-mediated gold nanostructure arrays exhibiting both narrow spectral features with a linewidth of ~8.2 nm and strong resonance intensity with an absorbance amplitude exceeding 95% [ 26 ]. Li et al designed and fabricated a gold nanodisk array-based SLR sensor for the detection of antimouse IgG protein, with a resultant protein sensitivity of up to 1.25 nm/nM [ 27 ].…”

Plasmonic Lattice Modes with High Quality Factor in Inhomogeneous Environment

“…Periodic metallic nanoparticle arrays have been extensively investigated owing to their excellent optical features [1], and plasmonic lattice modes (PLM) is one of them. The most typical property of PLM is the sharp variation of transmittance or reflectance due to the coupling between localized surface plasmon resonance and diffracted waves [2][3][4]. This characteristic provides a possibility to apply periodic metallic nanoparticle arrays in many fields [5][6][7][8].…”

Detailed formation mechanism of sharp plasmonic lattice modes on Au hemi-ellipsoid arrays in inhomogeneous environment

“…Among those properties, plasmonic lattice modes (PLM, also named as surface lattice modes) have attracted much attentions because the transmission of the arrays varies rapidly from the maximum to the minimum in a narrow wavelength band, * Author to whom any correspondence should be addressed. and forms a sharp valley [3][4][5][6][7][8][9][10][11][12][13][14]. This unique nature makes it possible to apply the periodic metallic nanoparticle arrays in sensors [5,7,[15][16][17][18], lasing [19][20][21], light emission [22][23][24], etc.…”