Conformal Graphene-Decorated Nanofluidic Sensors Based on Surface Plasmons at Infrared Frequencies

Abstract

An all-in-one prism-free infrared sensor based on graphene surface plasmons is proposed for nanofluidic analysis. A conformal graphene-decorated nanofluidic sensor is employed to mimic the functions of a prism, sensing plate, and fluidic channel in the tradition setup. Simulation results show that the redshift of the resonant wavelength results in the improvement of sensitivity up to 4525 nm/RIU. To reshape the broadened spectral lines induced by the redshift of the resonant wavelength to be narrower and deeper, a reflection-type configuration is further introduced. By tuning the distance between the graphene and reflective layers, the figure of merit (FOM) of the device can be significantly improved and reaches a maximum value of 37.69 RIU−1, which is 2.6 times that of the former transmission-type configuration. Furthermore, the optimized sensor exhibits superior angle-insensitive property. Such a conformal graphene-decorated nanofluidic sensor offers a novel approach for graphene-based on-chip fluidic biosensing.

A Review of Graphene-Based Surface Plasmon Resonance and Surface-Enhanced Raman Scattering Biosensors: Current Status and Future Prospects

“…On the other hand, if the sensitivity is investigated at different Fermi width and energy, the best sensitivity is the structure with the smallest fermi width and energy. At a width of 20 nm and a fermi energy of 0.1 eV, the sensitivity obtained was 6050 nm/RIU and 8004 nm/RIU, respectively [ 77 ]. The most important result of this simulation shows that the sensor sensitivity can be actively increased by lowering the Fermi energy level of graphene which can be done by adjusting the external voltage [ 77 , 78 ].…”

“… ( a ) Schematic of the conformal graphene-decorated nanofluidic channel (CGDNC) infrared sensor. ( b ) Investigation of sensor sensitivity based on data on the transmittance spectrum (adapted with permission from Reference [ 77 ], copyright MDPI). …”

Narrowband Perfect Absorber Based on Dielectric-Metal Metasurface for Surface-Enhanced Infrared Sensing

“…Surface-enhanced infrared optical sensing technology is powerful for direct label-free analysis with high reliability [1,2]. This technology can detect minute refractive index (RI) change of analyte [3][4][5]; more importantly, it can identify the vibrational mode of target molecules by combining with Fourier Transform Infrared Spectrometer [2,6], which plays an increasingly important role in chemical detection, food safety, and biosensing [7][8][9]. As a kind of fundamental device for surface-enhanced infrared sensing, plasmonic perfect absorbers based on varying metallic structures have been widely employed, such as Metal-Insulator-Metal (MIM) structure [10][11][12], Vertical-Square-Split Ring (VSSR) structure [13], Semiconductor-Metal-Semiconductor (SMS) structure [14], Hybrid metasurface [15], and so on.…”

CO2 and SO2 Pressure-Driven Adsorption by 3D Graphene Nanoslits: A Molecular Dynamics Study

“…Chandra et al have found an impressive adsorption of 4.3 mmol/g of CO 2 in highly microporous activated graphene [7]. In fact, the combination of multilayered 3D graphene membranes with nanopores has been used in desalination [8] and molecular separation [9] and in biomolecular and gas sensors [10,11].…”