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There are numerous pharmacological uses for watery solution's sucrose concentration, including the preservation of food and proteins. It is imperative to create a sucrose detector that is quick, precise, and sensitive. In this communication, a surface plasmon resonance biosensor (SPRB) is employed for the determination of sucrose concentration. To achieve improved sensitivity, a Si layer is inserted between a metal (Ag) thin film and a black phosphor (BPS) layer in the proposed SPRB so that it has the design N-FK51A prism/silver/Si/BPS/ sensing medium (SM). Due to the exceptional dielectric properties of the Si layer, which include a high refraction index and low loss, it has been demonstrated that a little change in the analyte's refractive index can result in a substantial shift in the angle of resonance. By optimizing the thicknesses of the Ag, Si, and BP sheets, the suggested SPRB achieved an extraordinarily high sensitivity of 322.66°/RIU. Due to its great sensitivity, the suggested SPRB is enticing for usage in numerous biosensing applications. [ABSTRACT FROM AUTHOR]

The scientific community works hard on developing reliable, rapid, highly sensitive, and low‐cost techniques to detect severe acute respiratory syndrome coronavirus‐2 (SARS‐CoV‐2). The current techniques can occasionally produce false‐positive results. The development of novel approaches for the identification of SARS‐CoV‐2 is a significant area of research because of the limitations of current methods. A biosensor based on a defective binary photonic crystal (PCL) is proposed to detect SARS‐CoV‐2 concentration herein. The model of pathogen concentration‐dependent refractive index of the analyte is taken into consideration. The concept of operation of the PCL sensor is based on the defect mode shift when any change in the refractive index of the defect layer occurs. The transmission spectra of the PCL are plotted and studied. An optimum incident angle of 80° and a defect layer thickness of 5 μm are found. The relationship between the defect mode's wavelength and the concentration of SARS‐CoV‐2 is investigated and a sensitivity of 2648.3 nm RIU−1 is attained. [ABSTRACT FROM AUTHOR]

Coronavirus disease (COVID-19) pandemic outbreak is being investigated by severe respirational syndrome coronavirus-2 (SARS-CoV-2) as a global health issue. It is crucial to propose sensitive and rapid coronavirus detectors. Herein, we propose a biosensor based on surface plasmon resonance (SPRE) for the detection of SARS-CoV-2 virus. To achieve improved sensitivity, a BiFeO3 layer is inserted between a metal (Ag) thin film and a graphene layer in the proposed SPRE device so that it has the structure BK7 prism/ Ag/ BiFeO3/ graphene/ analyte. It has been demonstrated that a small variation in the refractive index of the analyte can cause a considerable shift in the resonance angle caused by the remarkable dielectric properties of the BiFeO3 layer, which include a high index of refraction and low loss. The proposed device has shown an extremely high sensitivity of 293 deg/RIU by optimizing the thicknesses of Ag, BiFeO3, and the number of graphene sheets. The proposed SPRE-based sensor is encouraging for use in various sectors of biosensing because of its high sensitivity. [ABSTRACT FROM AUTHOR]

Surface plasmon resonance (SPR) is an emerging technology in the field of biosensors owing to its label-free and real-time detection of different biosamples. In this research, a highly sensitive optimized SPR sensor is designed with 2D materials like black phosphorous (BP) and graphene and proposed for refractive index sensing in the range 1.41 to 1.45, which corresponds to brain tumor cells. The finite element method (FEM) with the help of COMSOL Multiphysics software is employed for analysis of reflectivity and electric field near the sensing layer. The number of layers of BP and graphene are judiciously optimized to achieve maximum sensing performance and high evanescent field. The outcomes of the proposed sensor revealed that a maximum sensitivity of 324.25 deg./RIU, figure of merit of 34.025, and detection accuracy of 0.134 1/deg. are achieved in sensing refractive index in the range 1.41 to 1.45. So, the designed sensor can find suitable applications in biomedical industries. [ABSTRACT FROM AUTHOR]

A simple 2D SiC grating based surface Plasmon resonance (SPR) gas sensor operating in thermal infrared wavelengths is proposed for refractive index sensing. The performance of the SPR sensor in terms of quality factor, sensitivity and figure of merit were investigated by applying optical interrogation technique. The rigorous coupled waves analysis (RCWA) is used to analyze the proposed design. By means of numerical examples, the effects of the characteristics of the incident light and geometrical parameters on the behavior of the sensor performance are discussed. The design has been used to sense variations in the index of gases between 1.0 and 1.01. For some optimal parameters, our sensor shows excellent results for the detection of gases. With θ = 2 ∘ angle of incidence and φ = 45 ∘ conical angle ultra-high average sensitivity of 6561.8 nm / RIU is achieved. Our proposed device shows a sensitivity as high as 7800 nm / RIU , and a maximum figure of merit of 131.87 / RIU . This optical gas sensor has a much simpler design and higher sensitivity compared to other sensors reported previously. This is significant because our gas sensor has an important applications e.g. monitoring of combustible and the early detection of fires. [ABSTRACT FROM AUTHOR]

Plasmodium falciparum infections are the most common cause of malaria-related deaths. A significant difference between red blood cells with and without infection can be seen in their refractive indices, which can be used as a key indicator in the diagnosis of this disease. In this manuscript, a surface plasmon resonance (SPR)-based biosensor is suggested theoretically for the detection of infected red blood cells (IRBCs) with Plasmodium Falciparum. The proposed SPR sensor has the configuration: BK7 prism/Ag/BiFeO3/2D-nanomaterials/analyte. The suggested SPR sensor has a (BiFeO3) layer located between the metal (Ag) and 2D-nanomaterials to realize higher sensitivity. BiFeO3 layer exhibits outstanding characteristics, such as high index of refraction and small loss and has shown a significant shift in resonance angle within a minute variation in the analyte's refractive index. A variety of 2D materials, including MXene, Graphene, and Black Phosphor, are used to cover the surface of the SPR structure in order to develop the efficiency of the detector. The suggested detector can demonstrate an extremely high sensitivity of 461.43 deg/RIU by adjusting the thicknesses of Ag, BiFeO3, and the quantity of 2D-nanomaterial layers. The suggested SPR-based biosensor is hopeful for use in various sectors of biosensing due to its extraordinarily high sensitivity. [ABSTRACT FROM AUTHOR]

Diabetes is becoming a global problem since it is the leading cause of mortality for many people all over the world. As a result, a diabetes sensor that is accurate, quick, and sensitive is required. On the basis of a binary photonic crystal, a new bio-photonic detector has been built for sensing diabetes-affected cells. It has two layers of Ge and TiN, with a defect cavity chosen as a sample and placed in the middle. The suggested biosensor's detecting mechanism is based on altering the refractive index of the sensing sample, which causes a shift in the location of the resonant peak inside the photonic band gap of transmittance spectra. The suggested structure's transmittance qualities are examined using the transfer matrix approach. The impact of incidence angle (TE and TM polarization) and defect cavity thickness on the performance of our proposed biosensor has been investigated. The suggested biosensor has a sensitivity of 2676.66 nm/RIU at optimal conditions, which is exceptionally high when compared to several previous studies. In addition, the suggested biosensor with a very low detection limit has an ultra-high-quality factor and figure of merit. Furthermore, the suggested detector is simple to fabricate and has a low-cost structure, making it appealing for use in a variety of bio-sensing applications. [ABSTRACT FROM AUTHOR]

Today, detecting processes of waterborne bacteria in drinking water is a global challenge because these bacteria can lead to dangerous diseases to the human body. In this paper, we have developed a new sensor for the detection of waterborne bacteria based on a one-dimensional defective binary photonic crystal. The defect layer is taken as a water sample located in the middle of the photonic crystal structure. A resonant peak is then created within the photonic bandgap. The sensing mechanism of the proposed detector is based on the refractive index difference between pure water and waterborne bacteria samples. This index change leads to a shift in the resonant peak position in the transmission spectrum. The effects of many parameters, such as incident angle, defect layer thickness, thicknesses of periodic layers and the number of periods on the sensitivity are investigated. At the optimum conditions, the proposed sensor exhibits a sensitivity of 3639.53 nm/RIU which is ultra-high compared with recently published biosensor papers. It also showed a high-quality factor (7521.26), high figure of merit (8977.98 RIU−1) and low detection limit (1.77 × 10−5 RIU). The proposed design could distinguish between the different types of waterborne bacteria although the minute difference between their refractive indices. In addition to that, it has a simple design so that it can be easily fabricated. [ABSTRACT FROM AUTHOR]

The most common disease on the earth, cancer, has raised concerns about the health of humans. Early discovery is a crucial argument to increase treatment success. A surface plasmon resonance (SPR) biosensor having prism, silver, MXene and analyte is theoretically proposed and numerically simulated in this work for rapid and accurate detection of blood cancer cells. Many different prisms are examined. The structure with the lowest refractive index prism has shown the highest sensitivity, hence it is taken into consideration for additional studies. Since an MXene layer has a larger surface area, it enhances surface-biomolecule adsorption. The number of MXene sheets and silver layer thickness are optimized to improve the sensor sensitivity. The SPR sensor can attain a sensitivity of 232.25 deg/RIU for 50 nm silver with a bi-layer of MXene. We believe that the proposed sensor has a very simple structure to facilitate the fabrication and it will be encouraging to be used in biosensing. [Display omitted] • A surface plasmon resonance (SPR)-based sensor is proposed for blood cancer detection. • The findings demonstrate that the proposed sensor is more sensitive with an MXene layer. • The structure with the lowest refractive index prism has shown the highest sensitivity. • The SPR sensor can attain a sensitivity of 232.25 deg/RIU for 50 nm silver with a bi-layer of MXene. [ABSTRACT FROM AUTHOR]