Photonic Crystal Fiber Biosensor Research Articles

Design of Terahertz Refractive Index-Based Spiral Hollow-Core Photonic Crystal Biosensor Using Enhanced Probabilistic Pyramid Neural Networks for Brain Tumor Detection

Cancer diagnosis is difficult and costly due to the complexity of the brain. Photonic technology-based biosensors show potential for identifying malignant tissues, including brain tumors, but they are often costly, time-consuming, and computationally difficult. To address these challenges, we propose an enhanced probabilistic pyramid neural networks (EPPNN)-based hollow-core photonic crystal fiber (PCF) biosensor with terahertz refractive index (THzBio-ECPPN) for detection of cancerous brain tumors. The approach is divided into two stages: biosensor design and brain tumor detection. Initially, PCF geometry with suspended cladding and a spiral-shaped hollow-core in the terahertz (THz) band is proposed. The PCF biosensors’ characteristics are then calculated using the EPPNN model. The EPPNN model’s hyperparameters are modified using the circle-inspired optimization algorithm to maximize accuracy and minimize effective mode loss. The proposed biosensor is then used to identify brain tumors. Experimental evaluations utilizing MATLAB show that the suggested strategy surpasses earlier methods, with a higher sensitivity (98%). The sensor has exceptional performance characteristics, such as a high figure of merit of 1.25–1.35 RI range and sensitivity of 50000 nm RIU−1, indicating its potential for precise detection of changes in refractive index. This combination of photonic crystal structures and neural networks has enormous potential for improving cancerous tumor accuracy to 99.92%, precision to 99.23%, specificity to 99.73%,and sensitivity to 99.36% of brain tumor diagnosis.

Highly sensitive plasmonic-grating PCF biosensor for cancer cell detection

Highly sensitive biosensor based on D-shaped photonic crystal fiber (PCF) with plasmonic grating is introduced and analyzed. The suggested structure is tested using four different grating structures (rectangular, triangular, circular, or elliptical) on the polished surface of the D-shaped PCF. The sensing operation depends on surface plasmon resonance mechanism where the analyte refractive index (RI) is utilized to control the coupling between the core mode and surface plasmon mode via phase matching phenomenon. Rhodium is employed as a plasmonic material to induce the SPMs. The resonance (i.e., phase matching) wavelength is a function of the analyte RI. The geometrical parameters of the proposed structure are optimized using full vectorial finite element method to enhance the sensor sensitivity. The proposed biosensor can be utilized in the detection of different cancerous Basel, Breast and Cervical cells. The performance of the reported biosensor is investigated in terms of sensitivity, linear response, and fabrication tolerance. The reported biosensor has high sensitivities of 19,750 nm/RIU, 20,428 nm/RIU and 20,041 nm/RIU for the detection of Basel, Breast and Cervical cancer cells, respectively. The presented biosensor is a good candidate for biological sample detection and organic chemical sensing.

Cancer cell detection by plasmonic dual V-shaped PCF biosensor

In this paper, a highly sensitive plasmonic photonic crystal fiber (PCF) biosensor is reported for cancer cell detection. The modal analysis of the reported biosensor is performed using the full vectorial finite element method. The suggested PCF sensor has dual V-shaped groves to enhance the sensor sensitivity where two gold nano-rods are mounted on the etched surfaces. The main idea of the optical sensors is to track the electromagnetic coupling between the leaky core mode and the surface plasmon mode (SPM) at the metal/dielectric interface. When the SPM and one of the fundamental core modes are phase-matched, strong coupling occurs. Therefore, maximum confinement loss is achieved for the core-guided mode at the resonance wavelength, which depends on the analyte refractive index (RI). The V-shaped groove enhances the core/SPM coupling where high RI sensitivity of 24,000 nm/RIU is achieved along the RI range from 1.38 to 1.39, with a resolution of 2.703×10−6RIU. The potential of using the suggested RI sensor for cancer cell detection is then demonstrated. In this context, high sensitivities of 23,700 nm/RIU, 8,208 nm/RIU, and 14,428.6 are obtained for basal, cervical, and breast cancer cells with resolutions of 4.22×10−6RIU, 12.18×10−6RIU, and 6.93×10−6RIU, respectively. The achieved sensitivity and resolution are higher than those of the recently reported cancer biosensors. Moreover, the developed label-free biosensor is safer than other chemical and surgical techniques.

Highly Sensitive Photonic Crystal Fiber Biosensor Based on Surface Plasmon Resonance for Six Distinct Types of Cancer Detection

Highly Sensitive Photonic Crystal Fiber Biosensor Based on Surface Plasmon Resonance for Six Distinct Types of Cancer Detection

Refractometric Sensing of Protein in Urine by the Photonic Crystal Fiber Biosensor in THz Regime

The presence of albumin in human urine is one of the confirmed early symptoms of kidney dysfunction. A precise urine protein identification process is very important to monitor the kidney’s proper functioning. To identify the presence of albumin in urine, a refractometric protein sensing approach in the photonic crystal fiber (PCF) environment has been introduced here. A PCF geometry with suspended cladding and a circular hollow core has been proposed and investigated in the terahertz (THz) spectrum for protein identification in the liquid samples. Three levels of albumin concentrations in urine (7–125 mg/dl, 250–500 mg/dl, and 1000 mg/dl) are considered to evaluate the sensing performances of the proposed PCF. The numerical investigations are performed on the COMSOL Multiphysics platform where the finite element method (FEM) figures out the numerical outcomes. The performances of the proposed PCF exhibit highly sensitive characteristics for albumin identification in the different albumin concentration levels of urine. The sensitivity shows more than 98.5% for all the tested concentration levels due to the strategic selection of geometrical parameters and proper optimization. Alongside, negligible confinement loss of 10−16 cm−1 is attained at the same operating point of 4.3 THz. Furthermore, dispersion profiles and practical implementation strategies are also investigated and discussed in detail.

High birefringence photonic crystal fiber for glucose sensing

This paper focuses on designing a simple photonic crystal fiber (PCF) biosensor. The proposed glucose sensor is modelled by Lumerical software using the finite element method. To evaluate the efficiency of this model, different sensing properties such as birefringence, coupling length, and relative sensitivity are calculated at different air-filling fractions. The principle of this PCF is to detect the variations in the refractive index of the different concentration glucose solutions. The analyte will be injected into an elliptical channel surrounded by two rings of air holes in a hexagonal shape. Numerical simulations show that increasing the air-filling fraction yields high performance and more light confinement. At the air-filling fraction of 0.45, the maximum birefringence and relative sensitivity were 4.01 × 10−3 and 91%, respectively. Also, the coupling length reaches a minimum of 162.09 μm.

A High-Sensitivity Fiber Biosensor Based on PVDF-Excited Surface Plasmon Resonance in the Terahertz Band

In this paper, a D-type photonic crystal fiber (PCF) with Zeonex material as the substrate and polyvinylidene fluoride (PVDF) material as the surface plasmon resonance (SPR) excitation layer is proposed for biosensing in the terahertz (THz) band. Analyzed with a finite element method, the proposed biosensor has shown excellent sensing properties for analyte refractive indices ranging from 1.32 to 1.45. With a maximum sensor resolution of 8.40 × 10−7 refractive index unit (RIU) and a figure of merit of 39.42 RIU−1, the maximum wavelength sensitivity and amplitude sensitivity can reach 335.00 μm/RIU and −66.01 RIU−1, respectively. A ±2% fabrication tolerance analysis is also performed on the biosensor to prove its practical feasibility. We conclude that our proposed PCF biosensor utilizing PVDF-excited SPR can provide high sensitivity, and thus a compact, label-free, and convenient solution for biomedical liquid sensing in the THz band.

Sensitive biosensing based on a D-type photonic crystal fiber

We designed a D-type photonic crystal fiber biosensor based on surface plasmon resonance, verified the simulation results of the existing glucose concentration in the blood of diabetic patients, and used the finite element simulation software COMSOL for numerical simulation. The influence of structural parameters of the biosensor on the sensing performance is mainly studied. The maximum wavelength sensitivity of the sensor is 42000 nm RIU–1, maximum figure-of-Merit (FOM) of 429.61 RIU−1, linearity is 0.99607, and wavelength resolution is 3.33 × 10−6 RIU in the refractive index range of 1.29–1.37. The biggest highlight of this sensor is not only the simple design structure and ultra-high sensitivity, but also when the diameter of the outermost air hole changes from 0.3 μm to 1.15 μm, it does not affect the phase matching conditions of the coupling mode inside the fiber. We believe that this sensor is expected to be the most competitive instrument among biosensors.

High-Performance Photonic Crystal Fiber Biosensor Based on Surface Plasmon Resonance for Early Cancer Detection

High-Performance Photonic Crystal Fiber Biosensor Based on Surface Plasmon Resonance for Early Cancer Detection

Gold coated surface plasmon resonance based biosensor: An hexagonal photonic crystal Fiber platform

We numerically analyze a dual-core gold coated photonic crystal fiber (PCF) biosensor based on surface plasmon resonance that can be used for remote sensing applications in place of the traditional prism-based biosensor. Chemically stable active plasmonic material gold (Au) are positioned outside the fiber structure as a sensing layer to facilitate the construction of the sensor. From finite element method (FEM) based simulation, it is shown that the proposed sensor has the maximum wavelength sensitivity of 5000 nm/RIU. In addition, the amplitude sensitivity of the sensor is 267.66 RIU−1 with the resolution of 2.00 × 10−5 RIU−1 having sensing range of analyte refractive index 1.30 to 1.40. The suggested two-ring dual-core PCF sensor can be used to detect biological analytes, organic compounds, biomolecules, and other unidentified analytes due to its high sensitivity, enhanced sensing resolution, and suitable linearity properties. The proposed sensor has high sensitivity and wide operating range; from visible to mid-infrared which enables the detection of various biomolecules with different absorption or fluorescence spectra. Overall, the unique combination of structural design and optical properties make hexagonal PCF biosensor a promising and innovative platform for advanced and high-performance biosensing applications.

Design and analysis of a highly sensitive SPR based PCF biosensor with double step dual peak shift sensitivity

This paper introduces a comprehensive study of a quad-cluster multi-functional Photonic Crystal Fiber (PCF) sensor where gold and Aluminum doped with zinc oxide (AZO) were used as plasmonic materials. A maximum Amplitude Sensitivity (AS) of 5336 RIU−1 and Wavelength Sensitivity (WS) of 40,500 nm/RIU in y pol was obtained incorporating Gold as plasmonic material. When AZO was included as the plasmonic material, AS of 3763 RIU−1 & WS of 9100 nm/RIU for y polarization were determined. The RI detecting range was increased from 1.32 to 1.43 to 1.19–1.42 after using AZO instead of Au that opens up a new horizon for detection. A novel detection technique, ‘Double Step Dual Peak Shift Sensitivity (DS-DPSS)’ was proposed in sensing temperature where highest sensitivity of 1.05 nm/°C having resolution of 0.095 °C for x pol. was achieved. Due to its diverse functionality, the suggested sensor represents a significant advancement in the detection of numerous analytes in biochemical applications.

Design of a nanoscale gold-coated photonic crystal fiber biosensor

A simple two-layer refractive index sensor based on surface plasmon resonance has been proposed in this work, which evinces high sensitivity for detecting unknown analytes. This sensor design includes hexagonal- and octagonal-shaped air-hole rings, which have been introduced in the first and second layers, respectively. By performing this amalgamation of different types of air holes, this gold-coated plasmonic sensing scheme provides the broad sensing limit of the analyte, which is 1.32–1.40. The sensing performance has been examined by applying the finite element method, which is being used for modeling complex and irregular-shaped geometry. The wavelength interrogation method has demonstrated a maximal wavelength sensitivity of 9,000 nm/RIU (refractive index unit). The maximal amplitude sensitivity of 1902 RIU−1 has been exhibited in the y-polarized mode using the amplitude interrogation method. Moreover, the maximal sensor resolution of 1.11 × 10−5 RIU covers the entire sensing range. Furthermore, by adjusting the air-hole diameter, pitch, and depth of the gold layer coating, many more investigations have been demonstrated in this design. This highly sensitive sensor is very convincing to be used in many applications like chemical, biological, and also in physical sensing analyses.

A Dual-Core Surface Plasmon Resonance-Based Photonic Crystal Fiber Sensor for Simultaneously Measuring the Refractive Index and Temperature

In this correspondence, a new photonic crystal fiber biosensor structure on the basis of surface plasmon resonance is proposed for the measurement of the refractive index (RI) and TSM temperature simultaneously. In this design, the central and external surface of the biosensor structure are coated with thin gold film. A hole adjacent to the inner gold film is filled with temperature-sensitive material (TSM). With the implementation of internal and external gold coatings along with TSM, the biosensor achieves the measurement of the RI and temperature with two disjoint wavelength coverage. Numerical simulations and calculation results illustrate that the average wavelength sensitivity of the biosensor structure, respectively, achieves 7080 nm/RIU and 3.36 nm/°C with RI coverage from 1.36 to 1.41 and temperature coverage from 0 to 60 °C. Moreover, benefiting from realization of different wavelength regions in RI and temperature sensing, it is believed that the proposed biosensor structure for the measurement of the RI and temperature will have range applications in the fields of medical diagnostics and environmental assessments.

Design and numerical analysis of a highly sensitive nano-layer coated photonic crystal fiber biosensor

In this paper, a highly sensitive diabetes detection sensor based on photonic crystal fiber-gold plasmonic material is designed, proposed and analyzed. In this sensor, the application of a gold thin film increases the operating wavelength range (400 nm–1200 nm). The analyte, which is the cell, is placed outside the sensor and makes it easy to fabricate. The proposed sensor detects healthy and diabetic cells based on the refractive indices. Moreover, full-transistor modeling is presented to detect the probability of diabetes. In this model, healthy persons, persons with a low risk of diabetes and persons with a high risk of diabetes are diagnosed. Numerical results show that the proposed biosensor has a maximum amplitude sensitivity of 2127.7 RIU−1, amplitude resolution of 4.69 × 10−6 RIU, maximum wavelength sensitivity of 21 000 nm RIU−1 and wavelength resolution of 4.76 × 10−7 RIU.

Highly sensitive quasi-D-shaped photonic crystal fiber biosensor designed for the detection of RBC parasitized by Plasmodium falciparum for the early diagnosis of malaria

A simple quasi-D-shaped photonic crystal fiber (PCF)-based surface plasmon resonance biosensor is proposed for the early diagnosis of malaria that arises as a result of Plasmodium falciparum parasite development in erythrocytes in the human body. The flat surface of the D-shaped PCF is covered with a thin layer of TiO2 along with a gold layer. The finite element method (FEM) is used to numerically investigate the characteristics of the sensor. With the well-optimized set of parameters, the proposed sensor exhibits maximum spectral sensitivities of 42857.14 nm/RIU, 22105.26 nm/RIU, and 16206.90 nm/RIU with resolutions of 2.33 × 10−06 RIU, 4.52 × 10−06 RIU, and 6.17 × 10−06 RIU for ring, trophozoite, and schizont phases, respectively. The obtained amplitude sensitivities are 784.55 RIU−1, 491.02 RIU−1, and 407.99 RIU−1 and FOMs are 596.90 RIU−1, 423.98 RIU−1, and 341.63 RIU−1 for the three phases, respectively. Therefore, with the promising results and simplified practical realization, the proposed sensor can be an excellent candidate for the identification of Plasmodium falciparum phases in RBC for malaria diagnosis.

Design and numerical analysis of a circular SPR based PCF biosensor for aqueous environments

This paper presents the design and numerical analysis of a circular photonic crystal fiber (PCF) biosensor based on surface plasmon resonance (SPR) for aqueous environments. The proposed biosensor has a geometrical design that uses the cladding at the fiber's exterior to simplify the gold and analyte deposition process. The sensing characteristics and performances of the proposed biosensor are fully investigated with the finite element method. The investigation indicates that the plasmonic material's thickness affects the biosensor's performance. The results of the proposed biosensor demonstrate a wide refractive index range of 1.30 to 1.44, with the highest wavelength or spectral sensitivity as 21,000 nm/RIU and the highest resolution as 9.09×10−6 RIU. The proposed biosensor has a straightforward geometric profile. The proposed biosensor is stable and suited for aqueous surroundings and wide-range detection applications.

Highly sensitive V-shaped SPR PCF biosensor for cancer detection

In this paper, a novel design of photonic crystal fiber (PCF) biosensor based on surface plasmon resonance (SPR) is introduced and analyzed for cancer cell detection. The full vectorial finite element method (FVFEM) is used throughout the numerical analysis of the suggested biosensor. The reported PCF has a V-shaped surface that is coated with ZrN as a plasmonic material. A coupling occurs between the core guided mode and surface plasmon mode SPM which depends on the studied analyte. Such a coupling is improved by using the suggested V-shape geometry which increases the sensor sensitivity.The geometrical parameters are optimized to achieve high sensor sensitivity. The proposed biosensor has high optical sensitivity of 6214.28, 3800, and 5008.33 nm/RIU, for quasi-transverse magnetic (TM), and 6000 nm/RIU, 4400 nm/RIU, and 5333.3 nm/RIU, for quasi-transverse magnetic (TE), for breast, basal, and cervical cancer cells, respectively. The reported optical sensor can pave the way for efficient and simple technique for cancer detection with low cost and high sensitivity instead of surgical and chemical techniques.

Designing of Gold-Coated Photonic Crystal Fiber Biosensor Based on Surface Plasmon Resonance for Optimisation in Pollution Control

Designing of Gold-Coated Photonic Crystal Fiber Biosensor Based on Surface Plasmon Resonance for Optimisation in Pollution Control

High performance surface plasmon resonance-based photonic crystal fiber biosensor for cancer cells detection

High performance surface plasmon resonance-based photonic crystal fiber biosensor for cancer cells detection

Highly sensitive SPR-based PCF bio sensor for plasma cell detection in human blood for the detection of early stage cancer

This study investigates an extremely sensitive surface plasmon resonance (SPR)-based Photonic crystal fiber (PCF) biosensor to detect blood plasma cell. A blood sample is put into one of the PCF cladding's air holes. This results in a substantial confinement loss which is used to study as the analyte core mode, while the background is used as the silica mode. To induce plasmonic effects, the plasma sample is injected into one of the air holes in the PCF cladding and its outer covering is coated with Indium Tin Oxide (ITO). In the range of 1.3246–1.3634 for the analyte refractive index, this determination of plasma yielded a sensitivity of 6701.03 nm/RIU for x-polarization and 5154.63 nm/RIU for y-polarization. The provided sensor's sensing output is investigated by using Finite Element Method (FEM)-based programme with a detection limit of 0.0097 RIU overall. Using the analyte defect layer with varied refractive indices, we were able to generate a difference in the resonant peak positions. As a result of our simulation results, it is vital to highlight that the suggested sensor exhibits notable sensor performance for both polarization modes, allowing for more frequent light source selection during practical implementation. Our proposed sensor can detect organic chemicals, biochemical analytes, and can also be used extensively in medical diagnostics, according to the findings.