Proposed Surface Plasmon Resonance Biosensor Research Articles

Highly-Sensitive Polymer Optical Fiber SPR Sensor for Fast Immunoassay

A new type of human immunoglobulin G (IgG) sensors based on the surface plasmon resonance (SPR) in the low refractive index (RI) plastic optical fiber (POF) and an antibody immobilization method is presented. A 50-nm-thick gold film was formed on the polished D-shaped fiber surface by magnetron sputtering. The RI response of the POF sensor is 30 049.61 nm/RIU, which is 26.5 times higher than that of single mode fiber (SMF) SPR sensors. The proposed SPR biosensor can be developed by simple and rapid modification of the gold film with 11-mercapto undecanoic acid (MUA). Upon immobilization of the goat anti-human IgG antibody, the resonance wavelength shifts by 11.2 nm. The sensor can be used to specifically detect and quantify the human IgG at concentrations down to 245.4 ng/mL with the sensitivity of 1.327 7 nm per µg/mL, which offers an enhancement of 12.5-fold compared to that of the conventional SMF based SPR sensors. The proposed device may find the potential applications in the case of use at the point of care.

Multilayer designs comprising zirconium nitride and perovskites as a novel angular plasmonic biomedical sensor

Abstract In this paper, a comparison between different configurations of surface plasmon resonance (SPR) biosensors has been theoretically conducted to improve the performance of the designed biosensor. The proposed biosensor configurations contain zirconium nitride (ZrN) as an alternative plasmonic material, which comprises different perovskite materials (KNbO3, LiTaO3, LiNbO3, SrTiO3, and BaTiO3) in the visible region. Depending on the study calculations, the reflection spectra of the suggested designs were studied under the angular interrogation mode based on Fresnel coefficients for the transverse magnetic polarized light. The numerical findings demonstrated that the SPR biosensor, which has the configuration of [Prism/BaTiO3/ZrN/BaTiO3/Biosensing medium], represents the best biosensor due to its higher sensitivity and minimum reflectivity values. Meanwhile, sensitivity could receive 179.58 (deg/RIU). Therefore, it is believed that the proposed SPR biosensor designs could be promising through wide-ranging applications, specifically in biomedical, chemical, and environmental protection.

Numerical Study of Titanium Dioxide and MXene Nanomaterial-Based Surface Plasmon Resonance Biosensor for Virus SARS-CoV-2 Detection.

A novel surface plasmon resonance-based biosensor for SARS-CoV-2 virus is proposed in this article. The biosensor is a Kretschmann configuration-based structure that consists of CaF2 prism as base, at which silver (Ag), TiO2, and MXene nanolayers are used to enhance the performance. Theoretically, the performance parameters have been investigated by means of Fresnel equations and transfer matrix method (TMM). The TiO2 nanolayer not only prevents oxidation of Ag layer but also enhances the evanescent field in its vicinity. The sensor provides an ultrahigh angular sensitivity of 346°/RIU for the detection of SARS-CoV-2 virus. Some other performance parameters, including FWHM (full width at half maxima), detection accuracy (DA), limit of detection (LOD), and quality factor (QF) have also been calculated for proposed SPR biosensor with their optimized values 2.907°, 0.3439deg-1, 1.445 × 10-5, and 118.99 RIU-1, respectively. The obtained results designate that the proposed surface plasmon resonance (SPR) based biosensor has notably enhanced angular sensitivity as compared to previous results reported in the literatures till date. This work may facilitate a significant biological sample sensing device for fast and accurate diagnosis at early stage of SARS-CoV-2 virus.

Highly sensitive sensor based on SPR nanostructure employing graphene and perovskite layers for the determination of blood hemoglobin concentration

Hemoglobin (HB) is a protein that is responsible for transporting carbon dioxide and oxygen through the body. HB levels in the blood that are less saturated increase the risk of developing diseases including diabetes, thyroid dysfunction, anemia, etc. Rapid and sensitive determination of HB concentration in blood is an essential issue. In this communication, a surface plasmon resonance (SPR)-based sensor is proposed for HB determination. The device consists of a prism (BK7), silver (Ag), titanium dioxide (TiO2), hybrid inorganic-organic halide perovskites (MAPbBr3) and graphene (Gr) layers. The findings demonstrate that the proposed sensor is more sensitive than the conventional one made up without a perovskite layer. The layers of Ag, TiO2, MAPbX3, and Gr are optimized for higher performance. The highest sensitivity is found 224 deg./RIU at the optimized thicknesses of Ag, TiO2 and MAPbBr3 of 60 nm, 5 nm and 3 nm, respectively. Additionally, the number of graphene sheets is studied and optimized to four layers. The proposed SPR biosensor is encouraging for use in various sectors of biosensing.

Antimonene-Coated Uniform-Waist Tapered Fiber Optic Surface Plasmon Resonance Biosensor for the Detection of Cancerous Cells: Design and Optimization.

For early-stage cancer detection, a novel design of graphene-antimonene-coated uniform-waist tapered fiber optic surface plasmon resonance (SPR) biosensor is demonstrated. The proposed optical biosensor outperforms over a wide range of refractive index (RI) variations including biological solutions and is designed to detect various cancerous cells in the human body whose RIs are in the range of 1.36-1.4. Here, antimonene is used to enhance the performance of the designed SPR sensor for sensing cancer analytes because of its high binding energy toward adsorption of biomolecules and large active surface area. The design and analysis of the sensor are done with the help of a transfer matrix method-based simulation platform, and the effect of the taper ratio is also studied. The performance of the proposed SPR biosensor is evaluated with performance parameters such as sensitivity, full width at half maximum, detection accuracy (DA), figure of merit (FOM), and limit of detection (LOD). The numerical results show that the designed sensor is able to provide a sensitivity of 7.3465, 10.9250, 11.8914, and 15.2414 μm/RIU, respectively, for sensing skin, cervical, blood, and adrenal gland cancer with a maximum FOM of 131.1525 RIU-1, DA of 14.2126 μm-1, and LOD of 7.2 × 10-5 RIU. Based on the derived results, the authors believe that the designed SPR sensor could practically find its potential applications in the field of medical science for the early-stage diagnosis of cancer and hence, opens a new window in the field of biosensing.

Simulation study of reconfigurable surface plasmon resonance refractive index sensor employing bismuth telluride and MXene nanomaterial for cancer cell detection

In this study, a highly angular sensitive surface plasmon resonance (SPR) biosensor has been designed for cancer cell detection. The proposed surface plasmon resonance biosensor structure is based on Kretschmann configuration, which works on an angular interrogation technique. The proposed SPR biosensor has enormous possibility to detect the various kind of cancer cells. The refractive index alteration of different cancerous (skin, cervical and blood) cells is 1.360–1.390. The proposed SPR biosensor is stacked with multilayers having CaF2 prism, silver metal, bismuth telluride (Bi2Te3) and MXene (Ti3C2Tx) layers. The performance parameters like angular sensitivity, quality factor, detection accuracy, and electric field intensity distribution have been optimized in this article. Here, various kind of cancer cells (skin, cervical and blood) have been also analyzed and corresponding angular sensitives are 252.20, 305.70 and 319.46 deg R−1IU−1 respectively. The proposed SPR biosensor shows best results for blood cancer cell detection. Some other important performance parameters like detection accuracy, quality factor, and electric field intensity distribution have also been calculated for proposed SPR biosensor device. The simulation results have been performed by MATLAB 2019a software. The proposed SPR biosensor design may open a new way for the medical industry.

Modeling of surface plasmon resonance biosensor based on Ag/BiFeO3/Ni using 2D nanomaterial perovskite MAPbBr3

In the present work, the sensing performance analysis of a surface plasmon resonance (SPR) sensor for biological and chemical applications is reported. The structure studied consists of a silver nanofilm, the hybrid nanostructure of bismuth ferrite material (BiFeO 3 ), and a nickel nanofilm covered by a layer of perovskite CH 3 NH 3 PbBr 3 (MAPbBr 3 ) nanomaterial. Our analyses are based on the finite element method (FEM) and a monochromatic excitation of wavelength 633 nm. We numerically analyzed performance parameters such as angular sensitivity, sensitivity enhancement, factor of merit (FoM) and electric field distribution. We have shown that the proposed SPR biosensor exhibits very good detection performance in terms of sensitivity and FoM. Compared with the conventional SPR structure, the 2D nanomaterials have excellent properties, such as stronger absorption capacity, which improves the biological and chemical sensing ability of the sensor. The sensitivity and FoM of the optimized biosensor reaches 408 deg/RIU with 240% enhancement, and 93.12 RIU −1 with 138.78% improvement respectively, when the perovskite material layer covered the BK7/Ag/BiFeO 3 /Ni hybrid nanostructure; for a 0.005 RIU variation in the refractive index of the sensing medium. Therefore, our proposed design and study would be practically suitable for bio/chemical sensing and in biomedical application has excellent performance, with the available fabrication technologies. • We proposed a SPR nanostructured as a high multi-functional detection biosensor by the MAPbBr 3 perovskite nanomaterial layer: BK7/Ag/BiFeO 3 /Ni/MAPbBr 3 . • The optimized nanostructure shows the highest angular sensitivity of 408 deg/RIU. • Highest sensitivity enhancement 240% for bimetallic/nanomaterials based SPR biosensor. • This study demonstrated high FoM of 105.78 RIU {-1} with an enhancement of 171.23%.

Optimum Design of Surface Plasmon Resonance (SPR) Tapered Fiber Optic Biosensing Probe With Graphene–MoS2 Over Layers for DNA Hybridization

A novel graphene/MoS2-coated tapered fiber optic surface plasmon resonance (SPR) biosensing probe is presented for the first time to analyze the deoxyribonucleic acid (DNA) hybridization working in the near-infrared region (IR) of the electromagnetic spectrum with improved performance. A proper optimization mechanism is devised to study DNA hybridization concerning the taper ratio. A transfer matrix method (TMM) has been envisaged to study various performance parameters such as the figure of merit (F.O.M.), detection accuracy (D.A.), full width at half maximum (FWHM), and sensitivity. The proposed biosensor is very effectively able to distinguish between DNA hybridization and single-nucleotide polymorphisms (SNPs) by observing a considerable shift in SPR resonance wavelength and transmission dip. Due to the effect of optimized graphene/MoS2 nanostructured and tapering section of fiber, the proposed SPR biosensor work in the near-IR region is very much advantageous for further scope of sensing technology.

Performance evaluation of multifunctional SPR bimetallic sensor using hybrid 2D-nanomaterials layers

In this paper, we analyzed the sensing performance of the multifunctional surface plasmon resonance (SPR) biosensors based on bimetallic film (Ag/Al2O3), and a hybrid nanostructure of BaTiO3 and 2D nanomaterials (Ti3C2Tx, black phosphorus and BlueP/MoS2 heterostructure). Using excitation light at 633 nm, we numerically analyze performance such as angular sensitivity, peak sensitivity, figure of merit, and electric field strength. The study shows the proposed biosensor design exhibits a highest sensitivity of 504 deg/RIU with a 320% improvement over the conventional SPR sensor reported so far on similar 2D nanomaterials, and can also maintain a good quality SPR curve. The results of different proposed and optimized nano-configurations show that the improved angular sensitivity of 120%, 60%, 290% and 80% for BaTiO3, Ti3C2Tx, Black phosphorus and BlueP/MoS2, respectively, for a change in the refractive index (RI) of the sensing medium of 5×10−3 RIU. Similarly, the variation in field intensity at the sensing interface further confirms the high sensitivity obtained for our proposed SPR biosensor. Therefore, our proposed design would be practically suitable for biosensing with higher performance with the available fabrication technologies.

Highly Sensitive TiO2/Au/Graphene Layer-Based Surface Plasmon Resonance Biosensor for Cancer Detection.

In this article, a hybrid /Au/graphene layer-based surface plasmon resonance (SPR) sensor with improved sensitivity and capability for cancer detection is presented. The finite element method (FEM) was used for numerical analysis. The proposed SPR biosensor was structured based on the angular analysis of the attenuated total reflection (ATR) method for the detection of various types of cancer using the refractive index component. The resonance angle shifted owing to the increment of normal and cancerous cells’ refractive index, which varied between 1.36 and 1.401 for six different types of normal and cancerous cells. According to numerical results, the obtained sensitivities for skin (basal), cervical (HeLa), adrenal gland (PC12), blood (Jurkat), and breast (MCF-7 and MDA-MB-231) cancer cells were 210 deg/RIU, 245.83 deg/RIU, 264.285 deg/RIU, 285.71 deg/RIU, 292.86 deg/RIU, and 278.57 deg/RIU, respectively. Furthermore, the detection accuracy (DA), figure of merits (FOM), and signal-to-noise ratio (SNR) were also obtained, with values of 0.263 deg−1, 48.02 RIU−1, and 3.84, respectively. Additionally, the distribution of the electric field and the propagation of the magnetic field for resonant and non-resonant conditions of the proposed structure were illustrated. It was found that an enhanced field was exhibited on the surface of the plasmonic material for resonant conditions. We also measured the penetration depth of 180 nm using decayed electric field intensity. Furthermore, the impact of using a /Au/graphene layer was demonstrated. We further conducted analyses of the effects of the thickness of the gold layer and the effects of additional graphene layers on overall sensitivities for six different types of cancer. The proposed T/Au/graphene layered structure exhibited the highest overall sensitivity in terms of detecting cancerous cells from healthy cells. Moreover, the proposed sensor was numerically analyzed for a wide range of biological solutions (refractive index 1.33–1.41), and the sensor linearity was calculated with a linear regression coefficient (R2) of 0.9858. Finally, numerical results obtained in this manuscript exhibited high sensitivity in comparison with previously reported studies.

Graphene and Nickel Nanomaterials Based Surface Plasmon Resonance (SPR) Biosensor: A Theoretical Study

An extremely sensitive surface plasmon resonance (SPR) based biosensor has been simulated in the present study using an angular interrogation technique. The large surface area of the graphene layer facilitates biomolecule absorption. The SPR biosensor is proposed in a five-layer Kretschmann configuration with a ferromagnetic material and a silver layer. The proposed SPR biosensor’s sensitivity has been significantly raised in comparison to traditional film-based SPR biosensors. By refining the proposed structure to include a ferromagnetic materials nickel and monolayer of graphene with thicknesses of 15 nm and 0.34 nm and a silver layer of 45 nm, respectively, it is possible to increase sensitivity to 266°/RIU. Furthermore, the proposed SPR sensor design has a very small FWHM, a high detection accuracy (DA), and a high-quality factor (QF). Monolayer of graphene with a fixed mono-layer Nickle configuration were found to have the highest sensitivity of 266°/RIU. Additionally, it should be noted that the proposed SPR biosensor exhibits superior performance compared to SPR sensor parameters previously recorded.

A label-free SPR biosensor for specific detection of TLR4 expression; introducing of 10-HDA as an antagonist

Toll-like receptor 4 (TLR4) is actively involved in many health-related problems, including transplantation rejection and autoimmune diseases. Therefore, it is important to identify an antagonist to inhibit the TLR4-induced immune cell activation. In our previous study, 10-hydroxy-2-decanoic acid (10-HDA) was introduced as a potential antagonist for TLR4; however, possible interaction between 10-HDA and TLR4 needed to be detected. Due to the ability of surface plasmon resonance (SPR) biosensor to confirm the specific interactions between receptors and ligands, a new configuration of SPR biosensor proposed to detect the possible interaction between 10-HDA and TLR4. Hence, 10-HDA was immobilized using the (3-aminopropyl) triethoxysilane (APTES) polymer as a crosslinking agent on the Ag-MgF2 surface. Besides, genetically modified HEK293T cells with high TLR4 expression were used to study the possible interaction between 10-HDA and TLR4. Surprisingly, the SPR angle was significantly reduced in the presence of HEK cells expressing TLR4, while HEK cells without TLR4 did not affect the SPR angle. So, the proposed SPR biosensor successfully detected the interaction betweenTLR4 and 10-HDA. The sensitivity and detection limit of the biosensor were achieved at 0.05 and 0.5 million cells expressing TLR4, respectively, with a two-fold dynamic range.

Numerical approach to design the graphene-based multilayered surface plasmon resonance biosensor for the rapid detection of the novel coronavirus

In this article, a graphene-based multilayered surface plasmon resonance (SPR) biosensor of (BK7/WS2/Au/BaTiO3/Graphene) is proposed for the rapid detection of the novel coronavirus (COVID-19). The proposed SPR biosensor is designed based on the angular interrogation attenuated total reflection (ATR) method for rapid detection of the COVID-19 virus. The sensor’s surface plasmon polaritons (SPPs) and the sensing region refractive index (RI) are changed, owing to the interaction of various concentrated ligand-analytes. The specific ligand is mechanized with the proposed sensor surface and the target analyte that has flowed onto the sensing surface. The proposed sensor is capable of detecting the COVID-19 virus rapidly in two different ligand-analytes environments, such as: (i) the virus spike receptor-binding domain (RBD) as an analyte and monoclonal antibodies (mAbs) as a probe ligand, and (ii) the monoclonal antibodies (IgG or IgM) as an analyte and the virus spike RBD as a probe ligand. Due to the binding of the target ligand-analytes, the concentration level of the sensing region is incremented. As the increment in the concentration level, the RI of the sensing medium increases, therefore the change in RI causes the shift in the SPR angle resulting in the output reflectance intensity. The performance of the multilayered SPR sensor is analyzed numerically using the finite element method (FEM) method. Numerically, the proposed sensor provides the maximum angular shift sensitivity at 230.77 deg/refractive index unit (RIU), detection accuracy (DA) at 0.161 deg−1, and the figure of merits (FOM) is at 37.22 RIU−1. In addition, with each additional graphene layer number (L), the proposed sensor exhibits the angular shift sensitivity increment (1 + 0.7L) times. The novelty of the proposed multilayer (BK7/WS2/Au/BaTiO3/Graphene) sensor is highly angular sensitivity, and capable of detecting the COVID-19 virus rapidly without a false-positive report.

Influence of Stack Hybrid Configuration of MoS2 and Graphene on the Performance of Surface Plasmon Resonance Biosensor

This paper investigates the influence of various configurations and flakes of: i) graphene, ii) graphene/MoS2/graphene and iii) MoS2/graphene/MoS2 over a thin layer of gold on the performance of a surface plasmon resonance (SPR) biosensor. The reflectance curves of the proposed SPR biosensor are obtained, analyzed and compared for different combinations and thicknesses of the biosensors’ layers in refractive indices (RI) of 1 and 1.02, resembling an air and a bacterial medium, respectively. An in-depth analysis based on finite difference time domain method is performed to describe the sensor response considering sensitivity, full width at half maximum and minimum reflectance. The obtained results show that the sensitivity of the biosensor with a 50 nm Au and a 5 nm TiO2 (as the adhesive layer between the Au- layer and the prism) is equal to 61°/RIU. In order to increase further the sensitivity, different stacks and thicknesses of MoS2/graphene/MoS2 and graphene/MoS2/graphene configurations on the Au layer are added. The achieved outcomes reveal that the sensitivity is improved for a monolayer of MoS2 (1L_MoS2) sandwiched between double layers of graphene (2L_G) on 50 nm Au and 5 nm TiO2 (1L_MoS2/2L_G/1L_MoS2/50nmAu/5nmTiO2/Prism-BK7). This combination yields a sensitivity of 71.5 °/RIU for RI changes in the sensing medium (Δn) of 0.02 with a great detection accuracy of 0.33. We hope that – based on the outcomes of this investigation - the proposed structures can open new windows to improve the SPR biosensor detection of biological species.

A nanolayered structure for sensitive detection of hemoglobin concentration using surface plasmon resonance.

The objective of the proposed work is to design a biosensor that monitors hemoglobin (Hb) concentration using the combination of nanolayer, i.e., barium titanate (BaTiO3) and antimonene based on surface plasmon resonance (SPR) technique. Antimonene is used here as bio-recognition element (BRE) layer to attach the Hb analyte through physical adsorption due to its hydrophilic nature, higher adsorption energy and larger active surface area. The use of BaTiO3 adlayer (7 nm) just before antimonene is to enhance the refractive index (RI) sensitivity up to 1.90 times for the proposed SPR biosensor. The reason behind sensitivity enhancement is its high dielectric constant which enhances the electromagnetic field with in analyte medium. The performance of the biosensor is demonstrated with performance parameters namely sensitivity, detection accuracy (DA), figure of merit (FOM) and resolution. The proposed biosensor has potential to achieve much higher performance in terms of RI sensitivity of 303.83°/RIU, FOM of 50.39 RIU−1 and resolution of 0.021 g/l in comparison with reported biosensors in the literature for detection of Hb concentration. Thus, based on the obtained results one can say that the proposed work unlocks a reliable sensing in the field of medical science to detect hemoglobin-related diseases in human being.

Theoretical analysis of sensitivity enhancement of surface plasmon resonance biosensor with zinc oxide and blue phosphorus/MoS2 heterostructure

In this paper, an ultrasensitive surface plasmon resonance (SPR) biosensor structure (CaF2 Prism /ZnO/Au/BlueP-MoS2/Sensing medium) based on angular interrogation technique has been studied to see the effect of Blue Phosphorus/MoS2 heterostructure with an adhesive layer of zinc oxide (ZnO). The adhesive layer is ZnO used between calcium fluoride (CaF2) prism and gold (Au) layer. Transfer matrix method is used for numerical analysis at operating wavelength 633 nm. The layers ZnO and Blue Phosphorus/MoS2 heterostructure are optimized to achieve the maximum sensitivity with minimum reflectance. The performance parameters, such as sensitivity (2280RIU−1), quality factor (56.211RIU−1), detection accuracy (0.2810), full width at half maximum (4.0561), and limit of detection (4.3859 × 10−6) are calculated for proposed SPR biosensor at room temperature. For two layers of BlueP/MoS2 heterostructure, the maximum sensitivity is 2350RIU−1. The result shows that the sensitivity of proposed structure is 17.5% greater as compared to the conventional structure. Transverse magnetic (TM) field is plotted, and the value of penetration depth is calculated as 145.25 nm for proposed SPR sensor. The proposed SPR sensor could be very useful in the SPR chip to detect biomolecules or analyte in visible range.

Design and Numerical Analysis of a Graphene-Coated SPR Biosensor for Rapid Detection of the Novel Coronavirus.

In this paper, a highly sensitive graphene-based multiple-layer (BK7/Au/PtSe2/Graphene) coated surface plasmon resonance (SPR) biosensor is proposed for the rapid detection of the novel Coronavirus (COVID-19). The proposed sensor was modeled on the basis of the total internal reflection (TIR) technique for real-time detection of ligand-analyte immobilization in the sensing region. The refractive index (RI) of the sensing region is changed due to the interaction of different concentrations of the ligand-analyte, thus impacting surface plasmon polaritons (SPPs) excitation of the multi-layer sensor interface. The performance of the proposed sensor was numerically investigated by using the transfer matrix method (TMM) and the finite-difference time-domain (FDTD) method. The proposed SPR biosensor provides fast and accurate early-stage diagnosis of the COVID-19 virus, which is crucial in limiting the spread of the pandemic. In addition, the performance of the proposed sensor was investigated numerically with different ligand-analytes: (i) the monoclonal antibodies (mAbs) as ligand and the COVID-19 virus spike receptor-binding domain (RBD) as analyte, (ii) the virus spike RBD as ligand and the virus anti-spike protein (IgM, IgG) as analyte and (iii) the specific probe as ligand and the COVID-19 virus single-standard ribonucleic acid (RNA) as analyte. After the investigation, the sensitivity of the proposed sensor was found to provide 183.33°/refractive index unit (RIU) in SPR angle (θSPR) and 833.33THz/RIU in SPR frequency (SPRF) for detection of the COVID-19 virus spike RBD; the sensitivity obtained 153.85°/RIU in SPR angle and 726.50THz/RIU in SPRF for detection of the anti-spike protein, and finally, the sensitivity obtained 140.35°/RIU in SPR angle and 500THz/RIU in SPRF for detection of viral RNA. It was observed that whole virus spike RBD detection sensitivity is higher than that of the other two detection processes. Highly sensitive two-dimensional (2D) materials were used to achieve significant enhancement in the Goos-Hänchen (GH) shift detection sensitivity and plasmonic properties of the conventional SPR sensor. The proposed sensor successfully senses the COVID-19 virus and offers additional (1 + 0.55) × L times sensitivity owing to the added graphene layers. Besides, the performance of the proposed sensor was analyzed based on detection accuracy (DA), the figure of merit (FOM), signal-noise ratio (SNR), and quality factor (QF). Based on its performance analysis, it is expected that the proposed sensor may reduce lengthy procedures, false positive results, and clinical costs, compared to traditional sensors. The performance of the proposed sensor model was checked using the TMM algorithm and validated by the FDTD technique.

Improved Performance of Platinum Diselenide Based Surface Plasmon Resonance Biosensor Using Silicon

After the discovery of graphene in 2004, two-dimensional materials have attracted attention at large scale because of their peculiar structure and extraordinary properties. As they have large potential in future nano electronics, two-dimensional transition metal dichalcogenides has become most focus topic of study. Transition metal dichalcogenides with tunable finite band gap and significant transitional behavior are much suitable for the construction of electronic and optoelectronic devices of high-performance. However, platinum diselenide is group-10 transition metal dichalcogenides which occur naturally in one phase transition, which has been theoretically predicted as an excellent material. The proposed structure of surface plasmon resonance (SPR) -based biosensor consists of a silicon and two-dimensional nanomaterial platinum diselenide. The performance parameters of proposed biosensor (surface plasmon resonance-based) such as detection accuracy, figure of merit, sensitivity, full width at half maximum have been investigated. The sensitivity, detection accuracy, full width half maximum and figure of merit of proposed surface plasmon resonance biosensor having silver (50 nm), silicon (2 nm) and one layer of platinum diselenide with 2 nm thickness at 633 nm wavelength is 2200RIU–1 , 0.20 deg–1, 4.980 and 44.22 RIU–1 respectively. Silicon sheet is used in the middle of the Ag and platinum diselenide to prevent the oxidation of silver and enhance the sensitivity of platinum diselenide based surface plasmon resonance biosensor. The sensitivity of conventional surface plasmon resonance biosensor and the proposed surface plasmon resonance biosensor without silicon layer is 1700RIU–1 and 2000RIU–1 respectively. Surface plasmon resonance biosensor of device structure CaF2/Ag/Si/PtSe2 has higher sensitivity in comparison to device structures CaF2/Ag (conventional) and CaF2/Ag/PtSe2 (without Silicon Layer) by 29.41% and 10% respectively. Although the highest sensitivity obtained is 2620RIU–1 for 60 nm silver with 3 nm silicon layer except the platinum diselenide layer.

Giant Goos-Hänchen Shifts in Au-ITO-TMDCs-Graphene Heterostructure and Its Potential for High Performance Sensor.

In order to improve the performance of surface plasmon resonance (SPR) biosensor, the structure based on two-dimensional (2D) of graphene and transition metal dichalcogenides (TMDCs) are proposed to greatly enhance the Goos-Hänchen (GH) shift. It is theoretically proved that GH shift can be significantly enhanced in SPR structure coated with gold (Au)-indium tin oxide (ITO)-TMDCs-graphene heterostructure. In order to realize high GH shifts, the number of TMDCs and graphene layer are optimized. The highest GH shift (−801.7 λ) is obtained by Au-ITO-MoSe2-graphene hybrid structure with MoSe2 monolayer and graphene bilayer, respectively. By analyzing the GH variation, the index sensitivity of such configuration can reach as high as 8.02 × 105 λ/RIU, which is 293.24 times of the Au-ITO structure and 177.43 times of the Au-ITO-graphene structure. The proposed SPR biosensor can be widely used in the precision metrology and optical sensing.

Performance analysis of graphene-based surface plasmon resonance biosensor for blood glucose and gas detection

The present study exhibits excellent sensing characteristics of graphene-based prism-coupled surface plasmon resonance (SPR) biosensor for effectual sensing of both glucose concentrations in human blood samples in the range 25–175 mg/dl and gas with refractive index variations from 1.0000 to 1.0007 at a wavelength of 589 nm. The foremost attractiveness of the proposed SPR biosensor lies with excellent optical properties of N-FK51A-based glass prism along with the inclusion of a gold layer and a thin graphene layer. Transfer matrix method and angular interrogation technique are employed to envisage sharp SPR reflectance curves by optimizing the thickness of the gold layer and number of graphene layers. Aside this, an excellent electric field enhancement factor is accomplished near the graphene and sensing layer interface, which dramatically escalates the absorption of glucose and gas analytes. Subsequently, several performance measuring factors such as sensitivity, detection accuracy, resonance angle shift, and quality factor are thoroughly scrutinized and compared with other conventional SPR sensors. Moreover, simulation results reveal some noteworthy upshots like sensitivity of 275.15°/RIU, detection accuracy of 1.41/°, and quality factor of 76.2 that are obtained for glucose analytes, whereas sensitivity of 92.1°/RIU, detection accuracy of 2.55/° and quality factor of 230.2 are attained for gaseous analytes. Interestingly, it is found that the aforementioned parameters fitted excellently with a linear trend line, which leads to accurate investigation of glucose concentration as well as gaseous analytes. Hence the suggested structure opens up an avenue for suitable biomedical application.