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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]

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 chirped long-period grating inscribed in a planer optical waveguide sensor is demonstrated. The distribution of electric field within the structure has been obtained using boundary condition for the electric field equations at different dielectric boundaries. The transmission spectrum of the proposed sensor is obtained by transfer-matrix method. Further, the sensitivity for ambient refractive index and temperature has been analysed by observing the shift in resonance wavelengths. The presence of two dips in the transmission spectrum effectively doubles the sensitivity in comparison to the single resonance structure. We have achieved refractive index sensitivity of 5600 nm/RIU and temperature sensitivity of 0.8 nm/ °C, respectively. [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]

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]