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A novel design of an optical refractive index sensor based on surface plasmon resonance (SPR) has been offered in the article. The structure of the sensor is grounded on a Kretschmann configuration which comprises of CaF2 prism, silver (Ag) metal, beryllium oxide (BeO) nanomaterial, Nickel (Ni), and a heterostructure 2D nanomaterial (blue phosphorene/tungsten diselenide; BP/WS2). The analyte has been sensed on the 2D heterostructure material surface to examine the change in refractive index (RI). For prudent examination of the reflectivity of the proposed sensor, the transfer matrix method (TMM) has been employed. The optimization of sensitivity in terms of thickness and number of layers has also been investigated. Electric field intensity enhancement factor and phase interrogation parameters and normalized electric field distribution have also been utilized to validate the resonance angle position and to justify ultrahigh sensitivity. Utilizing the 2D nanomaterials intensifies the sensitivity of the proposed structure up to 401.2° per refractive index unit (deg/RIU). The FoM and detection accuracy (DA) is optimized up to 178.31 RIU−1 and 0.444 deg−1 respectively. The sensor offers a simple and selective structure with efficient cost and thickness. Additionally, the advantage of being real-time, stable, and label-free detection of an analyte sample with a very small amount of sample makes the proposed sensor a competing technology to be fabricated as a sensor chip for commercial applications. [ABSTRACT FROM AUTHOR]

A highly sensitive surface plasmon resonance biosensor employing BK7 prism, Silver (Ag), zinc oxide (ZnO), ferromagnetic material (Fe2O3), and two-dimensional (2D) nanomaterial black phosphorous (BP) has been proposed. Thin layers of two different oxide layers sandwiched between Ag and BP in Kretschmann configuration. The angular interrogation method–based numerical simulation is applied for modelling of high performance SPR biosensor at a wavelength of 633 nm (visible region). Transfer matrix method and finite element methods have been used to obtain [performance parameters. This sensor can detect malaria at different stages and provides a large range of refractive index (RI) sensing from 1.369 to 1.409. The RI for malaria stages, including the ring, trophozoite, and schizont stages, are 1.396, 1.381, and 1.371 respectively, with corresponding angular sensitivities of 367 deg/RIU, 297 deg/RIU, and 269 deg/RIU. The sensor offers an ultrahigh angular sensitivity for malaria detection in ring stage. This research could pave the way for an important bio sample detection apparatus that allows for quick and precise in ring stage diagnosis. [ABSTRACT FROM AUTHOR]

In the present study, an ultra-sensitive surface plasmon resonance biosensor is developed. The device is composed of a CaF2-prism, silver, silicon nitride, nickel, and black phosphorus have been deposited. The setup is grounded in the Kretschmann configuration and theoretically analyzed by means of transfer matrix method and Fresnel equations. For selective diagnosis of liver tissue and its mutation in terms of variation in RI, the biosensor provides an ultrahigh angular sensitivity of 383.62°/RIU for MET tissue and 403.92°/RIU for HCC tissue. The optimization of angular sensitivity and other sensor parameters in terms of thickness and number of layers has also been utilized. To validate the reflectance curve, electric field intensity enhancement factor and phase interrogation have also been conducted. The acquired results state that the proposed biosensor yields an enhanced sensitivity when compared to other reported results. Due to its advantage of fast, accurate and early-stage detection of liver mutations with a very small number of samples, this report may expedite a sensing device for commercial applications. [ABSTRACT FROM AUTHOR]

The present study reports screening of cancer cells at the earliest stages using prism coupling-based surface plasmon resonance biosensors in a theoretical manner. The SPR sensors designed on Kretschmann configuration consisting of several layers like silver (Ag) metal, beryllium oxide (BeO) and hetero-structure BlueP/WSe 2 layer deposited over BK7 glass prism. For maximum light absorption, a perovskite nano material, barium titanate (BaTiO 3) layer is placed between BeO and hetero-structure BlueP/WSe 2 to enhance the angular sensitivity. The light of 633 nm wavelength has been used for excitation of surface plasmon at metal dielectric interface. The refractive index of cancer cells lies between 1.360 and 1. 400. The optimized angular sensitivity of 216°/RIU and 360°/RIU for PCI-2 (normal, adrenal gland cancer), 248°/RIU and 254°/RIU for MDA-MB-231(normal, breast cancer cell) as well as 248°/RIU and 254°/RIU for MCF-7 (normal, breast cancer cell) respectively has been obtained. The maximum optimized angular sensitivity for adrenal gland cancer is 360°/RIU on employing perovskite layer. The sensor offers excellent performance parameters and covers wide range of refractive index sensing. [ABSTRACT FROM AUTHOR]

The present work has been performed with an intent of designing a robust, profound, and highly sensitive sensor for numerous explosive detections. The main objective of the present study is to design a simplified structure with fabrication feasibilities. The proposed structure of an explosive detector includes a hollow core surrounded with four sectored-type air holes in the cladding area and silica as background of the fiber which operates for 1–2 THz frequency band. Furthermore, the optical guiding property of the detector is examined, and numerical study has been performed. The modelling has been performed with the help of COMSOL Multiphysics 5.6a software based on finite element method, and Origin 2023 software is used for plotting and analyzing the characteristic curves. The suggested sensor structure has been analyzed for various explosives such as TNT, RDX, HMX, and PETN. Optical parameters such as effective refractive index, confinement loss, effective area, nonlinearity, propagation constant, and relative sensitivity have been evaluated. The proposed structure offers relative sensitivity of 84.02%, 69.42%, 71%, and 79.31% for TNT, RDX, HMX, and PETN samples, respectively. The proposed detector structure offers better sensing proficiency for explosive detection. The simplified design favors the fabrication possibilities and makes it economically effective. The proposed study will add up to the developments in the field of photonics and chemical detection and, moreover, will open new doors for better application for security and explosive sensing. [ABSTRACT FROM AUTHOR]

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°, 0.3439 deg−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. [ABSTRACT FROM AUTHOR]

The most popular method to determine the sensitivity of surface plasmon resonance (SPR) sensors in the last couple of decades has been angular interrogation. The silver layer (Ag), a 2D layer of TiO2, and dielectric material layer such as silicon (Si) with heterostructure material graphene are all stacked in the proposed SPR sensor. To increase sensitivity of SPR sensor in the visible area, the device structure focuses on the Kretschmann configuration, by which a TiO2 sheet is sandwiched between silver and silicon sheets. The proposed device structure makes use of the operational wavelength of 633 nm. The numerical simulation has been performed in MATLAB software in this device structure. The simulation results show that an analyte of refractive indices ranges 1.345–1.350. A single layer of silicon 3 nm and TiO2 10 nm makes up the suggested SPR configuration, which increases the sensitivity to 281° RIU−1. Herein, it has also been computed the figure of merit, detection accuracy, limit of detection, full width at half maximum, and transverse magnetic electric field intensity. The biomedical and chemical fields have benefited from the proposed SPR sensor structure design. [ABSTRACT FROM AUTHOR]

A Kretschmann configuration‐based surface plasmon resonance sensor is proposed. The sensor is made up of calcium fluoride prism, silver, silicon, and tungsten di selenide nanolayer. The theoretical and numerical study of surface plasmon resonance sensor is analyzed by angle interrogation method with the help of MATLAB 2017b. The transfer matrix method (TMM) is the foundation for simulation and a monochromatic light of wavelength 633 nm is considered as source. In the proposed device structure, each layer is arranged in vertical format to improve the electrical and optical properties. The refractive index for analyte is considered as 1.330 to 1.335. Silver (Ag) metal is used for the generation of surface plasmons. It has good chemical properties like metallic conductivity, chemical stability, bandgap, small work function, and acts as an adhesive layer between calcium fluoride prism and silicon layer. To improve the molecular contact and absorption, the transition metal dichalcogenide nanofilm tungsten di selenide (WSe2) is applied at the top. The sensitivity of 367.4 deg RIU−1, detection accuracy of 0.4169 deg−1, quality factor of 193.58, and full‐width half maximum of 1.8985 deg are obtained optimized performance parameters of the proposed device structure. [ABSTRACT FROM AUTHOR]

The extant work exhibits a unique design of surface plasmon resonance (SPR) which has been suggested for indications of different malarial disease stages. The device construction is founded on the Kretschmann configuration and consists of multiple layers, including BK7 prism, silver (Ag) metal layer, zinc oxide (ZnO), lead titanate (PbTiO3), and a heterostructure 2D nanomaterial (black phosphorus; BP) at the top. The angular reflectivity is evaluated using TMM stands for transfer matrix method. The thickness and number of layers have been studied for the optimization of sensitivity. Additionally, normalized electric field distribution, electric field intensity enhancement factor, and phase interrogation parameters have been applied to validate the position of occurrence of resonance angle and ultrahigh sensitivity. The equivalent angular sensitivity for the refractive indices of different stages of malaria infection (ring stage, trophozoite stage, and schizont stage) are 1.396, 1.381, and 1.371 for which the angular sensitivity is 387°/RIU, 305°/RIU, and 273°/RIU respectively. The suggested SPR sensor performs transcendentally when it comes to ring stage detection and corresponding quality factor of 107.12RIU-1 and detection accuracy of 0.27 deg-1. The sensor design can be crucial for future adavncement and practical implimentation of biosensors. [ABSTRACT FROM AUTHOR]

A surface plasmon resonance–based biosensor for the detection of chikungunya virus has been proposed in this article. The structure of the sensor is based on the Kretschmann configuration, which includes a BK7 prism, silver (Ag) metal, titanium dioxide (TiO2), a perovskite material (BaTiO3), and a heterostructure 2D nanomaterial (blue phosphorene/tungsten disulfide; BP/WS2). The surface of the 2D heterostructure material is employed for the detection of the analyte, aiming to investigating the alterations in refractive index. Using the transfer matrix method (TMM), the reflectivity of the proposed sensor is analyzed numerically. The investigation also explores the enhancement of sensitivity by considering variations in number and thickness of layers. To confirm the location of resonance angle and substantiate the ultrahigh sensitivity, an examination of the electric field intensity enhancement factor and normalized electric field distribution has been also conducted. The optimization of parameters for the proposed sensor revealed that platelets and plasma cells have a maximum sensitivity of 365°/RIU and 152°/RIU, figures of merit of 94.147 and 73.98, and detection accuracy of 0.2579 and 0.4859 deg−1. The normalized electric field plot suggests a penetration depth of the order of 102 nm which enables long-range sensing and strong field-analyte interaction. The sensor offers high sensitivity and stability and may find useful applications in biomedical industries. [ABSTRACT FROM AUTHOR]