Sensitivity Of Surface Plasmon Resonance Sensor Research Articles

Highly sensitive surface plasmon resonance sensor based on the anti-resonant fiber with six nested tubes

On the heels of the continuous development of optical fiber sensing technology, optical fiber sensors based on surface plasmon resonance (SPR) have attracted widespread attention. Herein, an SPR sensor based on the six nested anti-resonant fiber (ARF) is designed and analyzed by the finite element method (FEM). All the structural parameters are optimized to achieve high-sensitivity liquid refractive index detection. Filling the anti-resonant tube with plasmonic materials to excite SPR can further reduce the manufacturing complexity. The optimal ARF-SPR sensor has excellent characteristics, including an average wavelength sensitivity of 42,000 nm/RIU, maximum sensor length of 0.08 cm, and resolution of 1.61×10−6RIU. The ARF-SPR sensor has great potential in chemical analysis, biomedicine, and other fields.

A lipase-conjugated carbon nanotube fiber-optic SPR sensor for sensitive and specific detection of tributyrin.

As a low-density lipoprotein, tributyrin plays an essential role in food safety and human health. In this study, a novel lipase-conjugated carbon nanotube (CNT) surface plasmon resonance (SPR) fiber-optic sensor is used to specifically detect tributyrin for the first time. In this work, CNTs can be used as an amplifying material to significantly increase the sensitivity of SPR sensors due to their high refractive index and large surface area. CNTs can also be used as an enzyme carrier to provide abundant carboxyl groups for the specific binding of lipases. Covering the surface of the sensor with CNTs can not only enhance the performance of the sensor, but also provide sufficient detection sites for subsequent biomass detection, reduce the functionalization steps, and simplify the sensor preparation process. The experimental results demonstrate that the refractive index sensitivity of the traditional multimode fiber (MMF)-single mode fiber (SMF)-MMF transmissive optical fiber sensor is 1705 nm RIU-1. After covering the sensor with CNTs, the sensitivity is 2077 nm RIU-1, and the sensitivity has been improved very well. In addition, there are abundant functional groups on CNTs, which can provide abundant binding sites. Conjugating lipase on carbon nanotubes helps to achieve linear detection in the range of 0.5 mM to 4 mM tributyrin, with a sensitivity of 4.45 nm mM-1 and a detection limit of 0.34 mM, which is below the 2.26 mM detection standard and meets food safety monitoring requirements. Compared with other sensors, the optical fiber biosensor proposed in this study expands the concentration detection range of tributyrin. Furthermore, the sensor also has good stability, anti-interference performance and specificity. Therefore, the sensor proposed in this paper has good application prospects in the fields of food safety and biomedicine.

Design and Modeling of a Novel Highly Sensitive Surface Plasmon Resonance Sensor Applying Tin Selenide and Graphene for Cancer Detection

Design and Modeling of a Novel Highly Sensitive Surface Plasmon Resonance Sensor Applying Tin Selenide and Graphene for Cancer Detection

Theoretical Modeling of Surface Plasmon Resonance Biosensor Using Titanium Dioxide and Graphene Nanomaterial for Refractive Index Sensing

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.

Experimental study of SPR sensor performance enhancement by metal oxides

With the widespread application of fiber surface plasmon resonance (SPR) sensors in the field of biochemical sensing, especially in the detection of large molecules such as proteins, the sensitivity of traditional fiber SPR sensors has made it difficult to meet the requirements of detection accuracy in practical applications. This article proposes and proves an effective method for selecting the optimal metal oxide material to improve the sensing performance of SPR sensors. Metal oxides (TiO2 and ZnO) can improve the sensitivity by enhancing the evanescent field of fiber SPR phenomenon. Through simulation, it was found that when the metal oxide film of the composite film sensor maintains the same thickness, the metal oxide with a high effective refractive index (RI) has a better improvement effect on the sensitivity of the SPR sensor. Experimental results show that the maximum RI sensitivity of TiO2 composite film sensors and ZnO composite film sensors in the RI range of 1.333–1.420 is 15,200 nm/RIU and 13,600 nm/RIU, respectively. Compared to silver-based sensors, RI sensitivity has increased by 16.92 % and 4.62 %, respectively. To further verify the enhancement effect of different metal oxides on fiber sensors, another layer of PDMS film is deposited on TiO2 and ZnO films. Within the temperature sensing range, the maximum temperature sensitivity of these two composite film temperature sensors is 4.9 nm/°C and 4.3 nm/°C, respectively. Overall, metal oxides with high RI can improve the sensing performance of fiber optic sensors.

A highly sensitive surface plasmon resonance sensor based on black phosphorus in the visible regime

A highly sensitive surface plasmon resonance sensor based on black phosphorus in the visible regime

Numerical and analytical analysis of an ultrahigh sensitive surface plasmon resonance sensor based on a black phosphorene/graphene heterostructure.

In this study, a surface plasmon resonance biosensor using angular interrogation based on a black phosphorene (BP) and graphene (G) heterostructure as two-dimensional materials are designed to enhance the sensitivity of conventional biosensors. The proposed structure is composed of eight layers: FK51A coupling prism, silver (Ag) thin film as the plasmonic metal, gold (Au) nanolayer in a protective role, BP nanosheets as an evanescent field enhancer, G monolayer as an immobilization process facilitator, DNA aptamer as biorecognition element, and phosphate buffered saline as a running buffer and sensing medium. To evaluate the performance of the proposed biosensor, analytical parameters such as minimum reflectivity (R m i n ), sensitivity, as well as the full width at half-maximum (FWHM), detection accuracy (DA), and quality factor (QF) are systematically assessed by the use of the transfer matrix method analytically and the finite-difference time-domain method numerically, to validate each other. It is observed that the structure has been optimized with 1.49 (RIU) for the coupling prism and the heterostructure T i O 2/A g/A u/B P/G thicknesses of 65/35/1/3.18/0.34nm, respectively. It was revealed that the proposed biosensor offered the sensitivity of 356 (°/RIU), QF of 42.4 (R I U -1), R m i n of 0.07 (a.u), FWHM of 8.3 (degree), and DA of 0.22 (unitless) and outperformed those of other results published up to now from the sensitivity point of view.

Highly sensitive fiber SPR sensor based on InSe nanosheets

Surface plasmon resonance (SPR) optical fiber sensors exhibit advantages such as small size, immunity to electromagnetic interference, and corrosion resistance, and are currently widely applied in the field of biodetection. However, their sensitivity and reusability are still limited in detecting biomolecules, trace concentrations, and weak signals. This paper proposes an approach by utilizing indium selenide (InSe) nanoflakes to enhance the surface electric field strength of the metal layer. InSe is a two-dimensional material that exhibits higher charge carrier mobility and refractive index compared to traditional two-dimensional materials, thereby promoting electron transfer and inducing a larger SPR effect. By testing the sensors composed of InSe nanosheets with different thicknesses, it is found that the sensitivity of InSe nanosheets with a thickness of 40 nm is up to 4655.76 nm/RIU, which is much higher than the sensitivity of traditional Au film sensors and 52 % higher than that of MoS2-Au film SPR sensors with the same structure. Moreover, the sensor has a higher FOM value of 33.25 RIU−1 and shows excellent characteristics in repeatability and stability experiments. In this paper, a new method is proposed to enhance the sensitivity of SPR sensors and realize the monitoring of lower biomolecule concentration and weak signal. In addition, the great potential of indium selenide nanosheets in optical applications is emphasized.

Detection of blood cancer using highly sensitive surface plasmon resonance sensor based on MXene 2D nanomaterial

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.

Highly sensitive surface plasmon resonance sensor with surface modified MoSe2/ZnO composite film for non-enzymatic glucose detection

The rapid and accurate assessment of glucose concentration has been demonstrated to play a significant role in human health, such as the diagnosis and treatment of diabetes, pharmaceutical research and quality monitoring in the food industry, necessitating further development of the performance for glucose sensor especially at low concentrations. However, glucose oxidase-based sensors suffer from crucial restriction in bioactivity because of their poor environmental tolerance. Recently, catalytic nanomaterials with enzyme-mimicking activity, known as nanozymes, have gained considerable interest to overcome the drawback. In this scenario, we report an inspiring surface plasmon resonance (SPR) sensor for non-enzymatic glucose detection employing ZnO nanoparticles and MoSe2 nanosheets composite (MoSe2/ZnO) as sensing film, featuring desirable advantages of high sensitivity and selectivity, lab-free and low cost. The ZnO was used to specifically recognize and bind glucose, and further signal amplification was realized by incorporating of MoSe2 owing to its larger specific surface area and favorable bio-compatibility, as well as high electron mobility. These unique features of MoSe2/ZnO composite film result in an obvious improvement of sensitivity for glucose detection. Experimental results show that the measurement sensitivity of the proposed sensor could reach 72.17 nm/(mg/mL) and a detection limit of 4.16 μg/mL by appropriately optimizing the componential constitutions of MoSe2/ZnO composite. In addition, the favorable selectivity, repeatability and stability are demonstrated as well. This facile and cost-effective work provides a novel strategy for constructing high-performance SPR sensor for glucose detection and a prospective application in biomedicine and human health monitoring.

A novel surface plasmon resonance sensor sensitivity enhancement method for temperature measurement by depositing tungsten disulfide nanosheets on the silver film

Surface plasmon resonance (SPR) sensors are extensively used with refractive index and temperature sensing. A novel SPR sensor for temperature measurement is proposed in this paper. A novel two-dimensional material Tungsten disulfide is used to improve the sensitivity of this temperature sensor. Polydimethylsiloxane covers the sensing area to better sense changes in external temperature. The experimental results show that the SPR sensor can measure the temperature range of 30 °C − 100 °C with a temperature sensitivity of 2.03 nm/°C. This sensor has the merits of a simple structure, low manufacturing process cost, a broad range of detection, and high sensitivity compared to other temperature sensors. Therefore, the sensor has great potential for future applications in environmental monitoring, biomedicine, the food industry, and other production activities.

High performance surface plasmon resonance based sensor using black phosphorus and magnesium oxide adhesion layer

A five-layered Kretschmann configuration-based novel structure is designed for a highly sensitive surface plasmon resonance (SPR) sensor. An adhesion layer of magnesium oxide (MgO) is employed on the BK7 prism to avoid the adverse effects of metallic layers, which cause SPR broadening and a decrease in the resonance magnitude. A few layers of black phosphorus (BP) on top of the silver (Ag) metal layer are added to complete the structure, which becomes the BK7/MgO/Ag/BP configuration. The investigation is carried out using attenuated total reflection (ATR), while the widely used transfer matrix method (TMM) is applied to evaluate the performance of the SPR sensor. A separate analysis is performed using three thicknesses, 5 nm, 10 nm, and 15 nm of MgO, an optimized thickness of 40 nm of Ag, and eight layers of BP. The results revealed that the configuration BK7/MgO (10 nm)/Ag (40 nm)/BP (8 layers) delivers a maximum sensitivity (S) of 234°RIU−1. Moreover, the configuration BK7/MgO (5 nm)/Ag (40 nm)/BP (8 layers) delivers a maximum figure of merit (FOM) of 38.18°RIU−1. With these kinds of extraordinary features, it is expected that the proposed SPR sensor can be applied in different fields of biosensing.

Highly sensitive surface plasmon resonance sensor for refractive index detection of Helicobacter Pylori

Helicobacter Pylori (H-Pylori) is gram-negative and spiral micro-organism that is responsible for its colonization in gastric microniche. The outcome of recent studies indicates that the development of H-Pylori in human bodies results in peptic ulcers, gastric mucosa, and gastric cancer. Therefore, on-time diagnosis of H-Pylori infection is very important to overcome its adverse effects. In this work, we have adopted the surface plasmon resonance (SPR) sensor for the detection of H-Pylori infection in human bodies. The SPR phenomenon is initiated by placing a 40–50 nm thick layer of gold nanoparticles on the flat surface of the glass prism. Four different configurations are designed by immobilizing a layer of biocompatible materials. Probe 1, 2, 3, and 4 are designed by immobilizing the layers of silicon oxynitride (SiON), molybdenum oxide (MoS2), graphene oxide (GO), and graphene, respectively. Added to this, the specificity of all the sensor structures is attained by functionalizing them with a 0.11 nm thick layer of urease enzyme, which oxidizes only in the presence of H-Pylori. Thereafter, the sensing analysis of all the sensor probes is done in a wide range of refractive index (RI) from 1.3227 to 1.3382 which corresponds to the RI of human urine in presence of H-Pylori. The performance analysis of the sensor is done in the terms of sensitivity, detection accuracy (DA), quality factor (QF), the figure of merit (FoM), and dip of a figure of Merit (DFoM). Added to this, the signal propagation through all the sensor structure is analyzed by using two-dimensional finite-difference-time-domain (FDTD) method-based tool.

Numerical Study of Surface Plasmon Resonance Biosensor Using Aluminium Oxide and Bismuth Telluride Nanomaterials for Skin Cancer Cell Detection

In the present article, a highly angular sensitive surface plasmon resonance sensor has been studied for early detection of skin cancer cell. The device’s basic design is based on the Kretschmann configuration, which uses an angular interrogation technique. The surface plasmon resonance biosensor has a high potential for detecting skin cancer cells. The variation of refractive index has been taken 1.35–1.38 for basal cell cancer (skin cancer). The proposed device has been stacked with multilayers having silver metal, CaF2 prism, Al2O3, and Bi2Te3 layers. In this article detection accuracy, angular sensitivity, the distribution of electric field intensity and figure of merit as performance parameters have been reported. The optimized value of angular sensitivity is 257.33°RIU−1. Similarly, some other performance parameters like detection accuracy, penetration depth, quality factor and distribution of electric field intensity have also been evaluated and the values are 0.3143 deg−1, 80.8883 RIU−1, 4.82×105 V/m and 112 nm respectively. The numerical simulation has been evaluated by COMSOL multiphysics and MATLAB software. The proposed biosensor may have been used in biological and chemical sensor applications.

Wedged Fiber Optic Surface Plasmon Resonance Sensor for High-Sensitivity Refractive Index and Temperature Measurements

Here, we experimentally demonstrate a wedged fiber optic surface plasmon resonance (SPR) sensor enabling high-sensitivity temperature detection. The sensing probe has a geometry with two asymmetrical bevels, with one inclined surface coated with an optically thin film supporting propagating plasmons and the other coated with a reflecting metal film. The angle of incident light can be readily tuned through modifying the beveled angles of the fiber tip, which has a remarkable impact on the refractive index sensitivity of SPR sensors. As a result, we measure a high refractive index sensitivity as large as 8161 nm/RIU in a wide refractive index range of 1.333-1.404 for the optimized sensor. Furthermore, we carry out a temperature-sensitivity measurement by packaging the SPR probe into a capillary filled with n-butanol. This showed a temperature sensitivity reaching up to -3.35 nm/°C in a wide temperature range of 20 °C-100 °C. These experimental results are well in agreement with those obtained from simulations, thus suggesting that our work may be of significance in designing reflective fiber optic SPR sensing probes with modified geometries.

Highly sensitive surface plasmon resonance sensor for detection of Methylene Blue and Methylene Orange dyes using NiCo-Layered Double Hydroxide

Surface plasmon resonance (SPR) sensor is a versatile technique to detect toxic materials in the environment. In this study, the SPR technique was used to detect the environmental contaminant dyes such as methylene blue (MB) and methylene orange (MO). The surface of the gold layer was modified using NiCo-layered double hydroxide (LDH) which was fabricated with the electrodeposition method and characterized using field emission scanning electron microscopy, X-ray diffraction spectroscopy, and transmission electron microscopy. The thickness of LDH was controlled by deposition time and a homogeneous coating of LDH was obtained in the short time range of less than 150s. The adsorption of MB and MO on LDH was studied using the SPR technique based on angular modulation. Langmuir adsorption isotherm was fitted for data of adsorbents and the adsorption mechanism was described. The sensor limit and the response time were about 0.005 ppm and 268 s, respectively. It was proved that the sensitivity of the sensor can be controlled by the thickness of the LDH layer. Results indicated that the glass/Au/ NiCo-LDH system is fast and efficient for the detection of the MB and MO dyes in a short time.

Theoretical analysis and optimization of sensing parameters of surface plasmon resonance sensor

Abstract The right combination of substrate and metallic layer is very important to optimize the sensing parameters of surface plasmon resonance (SPR) sensors. These parameters are sensitivity, full width half maxima (FWHM) and reflectance minimum (R min) at resonance angle. It is shown in the present theoretical analysis that the right combination of substrate and metallic layer helps in reducing the number of layers in SPR multilayer structures without compromising the sensitivity of SPR sensors. The present study was performed on three layers and molybdenum disulfide (MoS2) based four layer SPR structures. Gold (Au) and silver (Ag) were used as metallic layers and dense flint (SF11) glass and barium flint (BAF10) glass were used as substrate material. The best sensitivity value was achieved with the combination of Au and BAF10 in both three and four layer structure. The optimized values of FWHM and R min were obtained using the combination of Ag and SF11 in both three and four layer structures.

Sensitivity calculation for different prism material based surface plasmon resonance sensor: a comparative study

In this theoretical work, the sensitivity of the surface plasmon resonance (SPR) sensor is studied in the presence alcoholic sensing medium. Here sensing medium is taken as alcohol at different concentrations i.e. 0%, 20%, 50%, 80% and 100%. The sensitivity is computed for the different SPR configurations in which five prism materials and three noble metals are considered. The performance of each configuration is comparatively analysed in terms of sensitivity. It is found that the BK7 material-based SPR sensor shows a high sensitivity value in comparison to other prism materials for all active noble metals (Au, Ag, and Cu). In addition to that sensitivity increases with respect to the alcohol concentration but its value decreases when concentration is more than 80%. This study may drive the new researchers to develop high sensitive SPR sensors for diverse applications.

High sensitivity surface plasmon resonance sensor based on D-shaped high birefringence photonic crystal fibre

A sensitivity refractive index (RI) sensor based on surface plasmon resonance (SPR) effect in D-shaped high birefringence photonic crystal fibre (PCF) is presented and studied by the finite element method (FEM). Through the designing of air holes arrangement in PCF, the birefringence of optical fibre is improved and the SPR effect of y-polarized core mode is directionally excited. The designed D-shaped PCF with gold film in the damaged air holes enhances the interaction of the evanescent field with the external medium. Simulation results indicate that the sensor has a sensing range from 1.30 to 1.37, and the average spectral sensitivity is 10348.3 nm/RIU. The maximum spectral sensitivity of 19,288 nm/RIU and a high resolution of 5.18 × 10−6 RIU can be obtained at 1.37. This high sensitivity sensor has broad application prospects in life science and other research fields.

High Sensitivity Surface Plasmon Resonance Sensor Based on a Ge-Doped Defect and D-Shaped Microstructured Optical Fiber.

In this work a plasmonic sensor with a D-Shaped microstructured optical fiber is proposed to detect a wide range of analyte refractive index by doping the pure silica core with distinct concentrations of Germanium Dioxide , causing the presentation of high spectral sensitivity. In this case, the fiber is shaped by polishing a coating of , on the region that will be doped with , in the polished area, a thin gold layer, which constitutes the plasmonic material, is introduced, followed by the analyte, in a way which the gold layer is deposited between the . and the analyte. The numerical results obtained in the study shows that the sensor can determine efficiently a range of 0.13 refractive index units , with a limit operation where varies from 1.32 to 1.45. Within this application, the sensor has reached an average wavelength sensitivity of up to . With this level of sensitivity, the D-Shaped format and wide range of detection, the proposed fiber has great potential for sensing applications in several areas.