Fano-Resonance in Hybrid Metal-Graphene Metamaterial and Its Application as Mid-Infrared Plasmonic Sensor

Abstract

Fano resonances in nanostructures have attracted widespread research interests in the past few years for their potential applications in sensing, switching and nonlinear optics. In this paper, a mid-infrared Fano resonance in a hybrid metal-graphene metamaterial is studied. The hybrid metamaterial consists of a metallic grid enclosing with graphene nanodisks. The Fano resonance arises from the coupling of graphene and metallic plasmonic resonances and it is sharper than plasmonic resonances in pure graphene nanostructures. The resonance strength can be enhanced by increasing the number of graphene layers. The proposed metamaterial can be employed as a high-performance mid-infrared plasmonic sensor with an unprecedented sensitivity of about 7.93 μm/RIU and figure of merit (FOM) of about 158.7.

Enhanced Molecular Infrared Spectroscopy Employing Bilayer Graphene Acoustic Plasmon Resonator

“…The graphene plasmon mode possesses particularly the advantage of ultra-broad and fast tunability by tuning the Fermi energy via electrical doping [ 3 , 38 ]. Thus, the molecular vibrational fingerprints of protein sensing analytes can be sensitively detected by gate voltage controlling.…”

Theoretical Analysis of Terahertz Dielectric–Loaded Graphene Waveguide

“…In the calculation, the graphene layer is modelled as an electric field-induced surface current J = σ g E on the surface of the substrate, thus neglecting the thickness of the graphene layer. Within the random-phase approximation, the complex optical conductivity of graphene [ 61 , 62 , 63 ] consists of the interband and intraband contributions in the THz range, that is σ g = σ intra + σ inter , with: …”

Infrared Polaritonic Biosensors Based on Two-Dimensional Materials

“…The curve indicates that such sensor can still work in mid-IR range even if the thickness decreases to only few nanometers scale. Based on this work, a fano-resonance hybrid graphene/metal sensor was also demonstrated [ 80 ], of which the resonance intensity can be strengthened by adding the graphene layers, exhibiting a FOM of approximately 158.7 and an outstanding sensitivity of about 7.93 µm/RIU. Treating such hybrid graphene-Au nanoantenna as a biosensor with boronic acid-pyrene (BAP) and exposing it to glucose solutions, the plasmonic resonance (ω r ) shifted to lower wavenumbers and demonstrated a detection range from 2 nM to 20 mM ( Figure 4 g).…”