scholarly journals Ultrasensitive Biosensor with Hyperbolic Metamaterials Composed of Silver and Zinc Oxide

Nanomaterials ◽  
2021 ◽  
Vol 11 (9) ◽  
pp. 2220
Author(s):  
Shuhan Chen ◽  
Shiqi Hu ◽  
Yichen Wu ◽  
Dingnan Deng ◽  
Yunhan Luo ◽  
...  

We propose a hyperbolic metamaterial-based surface plasmon resonance (HMM-SPR) sensor by composing a few pairs of alternating silver (Ag) and zinc oxide (ZnO) layers. Aiming to achieve the best design for the sensor, the dependence of the sensitivity on the incidence angle, the thickness of the alternating layer and the metal filling fraction are explored comprehensively. We find that the proposed HMM-SPR sensor achieves an average sensitivity of 34,800 nm per refractive index unit (RIU) and a figure of merit (FOM) of 470.7 RIU−1 in the refractive index ranging from 1.33 to 1.34. Both the sensitivity (S) and the FOM show great enhancement when compared to the conventional silver-based SPR sensor (Ag-SPR). The underlying physical reason for the higher performance is analyzed by numerical simulation using the finite element method. The higher sensitivity could be attributed to the enhanced electric field amplitude and the increased penetration depth, which respectively increase the interaction strength and the sensing volume. The proposed HMM-SPR sensor with greatly improved sensitivity and an improved figure of merit is expected to find application in biochemical sensing due to the higher resolution.

2020 ◽  
Vol 50 (1) ◽  
Author(s):  
Daquan Yang ◽  
Bing Duan ◽  
Xuan Zhang ◽  
Hui Lu

A nanoslotted microring resonator (NSMR) with enhanced light-matter interaction has been designed, which can be used for high sensitive refractive index sensing. The performance of the device is investigated theoretically based on a three-dimensional finite-difference time-domain (3D-FDTD) method. In order to achieve high figure of merit sensing, the nanoslot geometry is exploited to make the optical field strongly localized inside the low index region and overlap sufficiently with the analytes. By using the 3D-FDTD method, the proposed NSMR sensor device achieves a high Q-factor (Q > 105) and sensitivity ~100 nm/RIU (RIU – refractive index unit). Moreover, the strong light confinement introduced by the nanoslot in NSMR results in the sensor figure of merit as high as 6.73 × 103. Thus, the design we proposed is a promising platform for refractive index-based biochemical sensing and lab-on-a-chip applications.


2001 ◽  
Vol 16 (3) ◽  
pp. 837-843 ◽  
Author(s):  
Xinfeng Tang ◽  
Lidong Chen ◽  
Takashi Goto ◽  
Toshio Hirai

Single-phase filled skutterudite compounds, CeyFexCo4−xSb12 (x = 0 to 3.0, y = 0 to 0.74), were synthesized by a melting method. The effects of Fe content and Ce filling fraction on the thermoelectric properties of CeyFexCo4−xSb12 were investigated. The lattice thermal conductivity of Ce-saturated CeyFexCo4−xSb12, y being at the maximum corresponding to x, decreased with increasing Fe content (x) and reached its minimum at about x = 1.5. When x was 1.5, lattice thermal conductivity decreased with increasing Ce filling fraction till y = 0.3 and then began to increase after reaching the minimum at y = 0.3. Hole concentration and electrical conductivity of Cey Fe1.5Co2.5Sb12 decreased with increasing Ce filling fraction. The Seebeck coefficient increased with increasing Ce filling fraction. The greatest dimensionless thermoelectric figure of merit T value of 1.1 was obtained at 750 K for the composition of Ce0.28Fe1.52Co2.48Sb12.


Sensors ◽  
2021 ◽  
Vol 21 (18) ◽  
pp. 6164
Author(s):  
Treesukon Treebupachatsakul ◽  
Siratchakrit Shinnakerdchoke ◽  
Suejit Pechprasarn

This paper provides a theoretical framework to analyze and quantify roughness effects on sensing performance parameters of surface plasmon resonance measurements. Rigorous coupled-wave analysis and the Monte Carlo method were applied to compute plasmonic reflectance spectra for different surface roughness profiles. The rough surfaces were generated using the low pass frequency filtering method. Different coating and surface treatments and their reported root-mean-square roughness in the literature were extracted and investigated in this study to calculate the refractive index sensing performance parameters, including sensitivity, full width at half maximum, plasmonic dip intensity, plasmonic dip position, and figure of merit. Here, we propose a figure-of-merit equation considering optical intensity contrast and signal-to-noise ratio. The proposed figure-of-merit equation could predict a similar refractive index sensing performance compared to experimental results reported in the literature. The surface roughness height strongly affected all the performance parameters, resulting in a degraded figure of merit for surface plasmon resonance measurement.


2021 ◽  
Author(s):  
Gangqi Wang ◽  
Fengjie Zhu ◽  
Tingting Lang ◽  
Jianjun Liu ◽  
Zhi Hong ◽  
...  

Abstract In this paper, a terahertz (THz) biosensor based on all-metal metamaterial is theoretically investigated and experimentally verified. This THz metamaterial biosensor uses stainless steel materials that are manufactured via laser-drilling technology. The simulation results show that the maximum refractive index (RI) sensitivity and the figure of merit (FOM) of this metamaterial sensor are 294.95 GHz/RIU and 4.03, respectively. Then, bovine serum albumin (BSA) was chosen as the detection substance to assess this biosensor’s effectiveness. The experiment results show that the detection sensitivity is 72.81 GHz/(ng/mm2) and the limit of detection (LOD) is 0.035 mg/mL. This THz metamaterial biosensor is simple, cost-effective, easy to fabricate, and have great potential in various biosensing applications.


2020 ◽  
Vol 128 (8) ◽  
pp. 1133
Author(s):  
А.Б. Сотский ◽  
С.С. Михеев ◽  
Н.И. Стаськов ◽  
Л.И. Сотская

Integral expressions for the reflectance and transmittance spectra of the structure consisted of two thin layers deposited on opposite faces of a plane-parallel substrate at oblique illumination of the structure with partially coherent light are obtained. As a result of the asymptotic analysis of the integrals, approximate analytical formulae are established for calculating the indicated spectra, convenient for use in solving inverse spectrophotometry problems. An aluminum doped zinc oxide layer deposited on a glass substrate is studied. The spectra of the refractive index and absorption coefficient of the layer and the substrate, as well as the thickness of the layer, are determined by processing the reflectance and transmission spectra of the structure, measured for s- and p- polarized waves at two angles of light incidence. The found parameters are used in computational experiments to estimate the applicability limits of the formulated approximations.


2020 ◽  
Vol 457 ◽  
pp. 124641 ◽  
Author(s):  
Liuwen Zeng ◽  
Miao Chen ◽  
Wei Yan ◽  
Zhaofeng Li ◽  
Fuhua Yang

2013 ◽  
Vol 446-447 ◽  
pp. 259-262
Author(s):  
J.H. Gu ◽  
T. Zhang ◽  
Z.Y. Zhong ◽  
C.Y. Yang ◽  
J. Hou

Aluminium doped zinc oxide (AZO) thin films were prepared by magnetron-sputtering. The optical and structural properties of the films were investigated by optical transmission spectra and X-ray diffraction (XRD) measurements, respectively. The results indicate that the AZO films have hexagonal wurtzite structure with highly c-axis preferred orientation. The optical and structural properties of the films are observed to be subjected to the argon pressure. The AZO film prepared at the argon pressure of 0.5 Pa exhibits the largest crystallite size and the highest average visible transmittance. Also, the refractive index and optical energy-gap of the films were determined by optical characterization methods. The dispersion behavior of the refractive index was studied using the Sellmeier’s dispersion model.


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