MATLAB Simulation-Based Theoretical Study for Detection of a Wide Range of Pathogens Using 1D Defective Photonic Structure

Detection and photothermal inactivation of Gram-positive and Gram-negative bloodstream bacteria using photonic crystal biosensor and plasmonic core-shell

Plasmonics and core-shell nanomaterials hold great potential to develop pharmaceuticals and medical equipment due to their eco-friendly and cost effective fabrication procedures. Despite these advancements, combating drug-resistant bacterial infections remains a global challenge. Therefore, this study aims to introduce a tailored theoretical framework for a one-dimensional (1D) photonic crystal biosensor (PCB) composed of (ZrO2/GaN)N/defect layer/(ZrO2/GaN)N, designed to detect Gram-positive and Gram-negative bloodstream bacteria employing the transfer matrix method (TMM). In addition, using the finite difference methods (FDM), the photothermal inactivation of bloodstream bacteria with plasmonic core-shell structures (FeO@AuBiS2) was explored using key factors such as light absorption, heat generation, and thermal diffusion. By incorporating six dielectric layers and contaminated blood into the proposed PCB, a maximum sensitivity of 562 nm per RIU was recorded, and using rod-shaped plasmonic core-shell structures, 5.8 nm-1 light absorption capacity and 152 K change in temperature were achieved. The maximum detection sensitivity, light absorption, heat conduction and heat convection capacity of the proposed 1D PCB and plasmonic core-shell show an effective approach to combating drug-resistant bacteria.

A bacteriorhodopsin multisensor system for qualitative and quantitative monitoring of methanol, ethanol, propanol, and butanol under extreme conditions

One of the most serious problems in waste biodegradation and biofuel production is the lack of adequate systems for monitoring reaction media. It has been demonstrated that the bacteriorhodopsin of Halobacterium salinarum is capable of generating photoelectric signals that can be modulated as a function of a chemical environment containing ethanol, methanol, propanol or butanol. The chemical modification of retinal (proton substitution with a fluorine atom at the 10, 12, or 14 position) and genetic modification of protein (aspartic acid 96 substituted with asparagine) may enhance the responses of bacteriorhodopsin systems. The responses of single elements to alcohols form characteristic response patterns. These patterns constitute the basis for the construction of the biosensor, a bacteriorhodopsin multisensor system equipped with artificial neural network methodology for monitoring these alcohols under extreme environmental conditions such as high or low pH and high temperature. It is, to the author's knowledge, the first time that the application of a constructed biosensor for monitoring thermophilic (55 °C) production of ethanol during paper and pulp wastewater degradation and thermophilic (55 °C) methanol digestion in methanol-rich wastewater from pulp and paper factories has been presented.

MATLAB simulation based study on poliovirus sensing through one-dimensional photonic crystal with defect

The present work, theoretically examined the poliovirus sensor model composed of one-dimensional photonic crystal with defect. The transfer matrix method with the help of MATLAB software has been used to detect poliovirus present in the water sample. The main objective of the present work is to design an efficient sensor by identifying the minute variation in the refractive index of water sample due to change in the poliovirus concentration present in the sample. The alternate layers of aluminum nitride and gallium nitride has been taken to realize Bragg reflector having defect layer of air at center of the Bragg reflector. The effect of change in thickness of defect layer region, period number and incident angle corresponding to transverse electric wave has been examined to optimize the structure which correspond maximum performance of the proposed poliovirus sensing structure. The maximum performance of the structure has been obtained with optimum value of defect layer thickness 1200 nm, period number 10 and incident angle 40°. Under optimum condition maximum sensitivity of 1189.65517 nm/RIU has been obtained when the structure is loaded with waters sample of poliovirus concentration C = 0.005 g/ml whereas figure of merit, quality factor, signal to noise ratio, dynamic range, limit of detection and resolution values become 2618.28446 per RIU, 3102.06475, 2.27791, 2090.99500, 1.91E-05 and 0.24656 respectively.

A doped-polymer based porous silicon photonic crystal sensor for the detection of gamma-ray radiation

In this research, a theoretical investigation of the one-dimensional defective photonic crystals is considered for the detection of gamma-ray radiation. Each unit cell of the considered one-dimensional photonic crystals (1D PhCs) is composed of two layers designed from porous silicon infiltrated by poly-vinyl alcohol polymer doped with crystal violet (CV) and carbol fuchsine (CF) dyes (doped-polymer) with different porosity. In addition, a single layer of doped-polymer is included in the middle of the designed 1D PhCs to stimulate the localization of a distinct resonant wavelength through the photonic band gap. In particular, the appearance of this resonant mode represents the backbone of our study towards the detection of γ-ray radiation with doses from 0 to 70 Gy. The Bruggeman's effective medium equation, the fitted experimental data to the refractive index of the doped-polymer, and the Transfers Matrix Method (TMM) serve as the mainstay of our theoretical treatment. The numerical findings provide significant contributions to some of the governing parameters such as the thicknesses of the considered materials on the performance of the presented sensor, the effect of incidence angle and the porosity of the considered materials on the resonance wavelength. In this regard, at optimum values of these parameters the sensitivity, quality factor, signal-to-noise ratio, detection limit, sensor resolution, and figure of merit that are obtained are 205.7906 nm RIU^-1, 9380.483, 49.315, 2.05 × 10^-5 RIU, 3.27 × 10^-5, and 2429.31 RIU^-1, respectively. Therefore, we believe that the suggested design could be of significant interest in many industrial, medical, and scientific applications.

High-performance Bloch surface wave biosensor based on a prism-coupled porous silicon composite structure for the detection of hemoglobin

Biosensors have various potential applications in biomedical research and clinical diagnostic, especially in detection of biomolecules in highly diluted solutions. In this study, a high-performance Bloch surface wave biosensor was constructed for the detection of hemoglobin. The procedure consisted of designing a porous silicon-based Kretschmann configuration to ensure excitation of the Bloch surface wave. The performance of the resulting sensor was then optimized by adjusting the buffer layer parameters based on the impedance matching method. The results showed an increase in the quality factor and figure of merit of the biosensor as a function of the decrease in thickness and refractive index of the buffer layer. The combination of the two optimization methods resulted in the quality factor and figure of merit of the optimized biosensor reaching as high as Q = 6967.4 and FOM = 11050RIU^-1, respectively. In sum, the designed biosensor with high performance looks promising for future detection of hemoglobin.

Conventional Biophotonic Sensing Approach for Sensing and Detection of Normal and Infected Samples Containing Different Blood Components

The present research work focused on the biosensing capabilities of one-dimensional (1D) defected photonic crystal (PC). This proposed structure is capable of simultaneously discriminating between normal and infected samples containing the platelet, plasma, and hemoglobin components of blood. The proposed biosensor was designed by creating a defect layer D of air in the middle of 1D PC (PQ)N to form modified 1D PC with a defect as (PQ)N/2D(PQ)N/2. The period number (N) of 1D PC (PQ)N was chosen to be 10. The cavity region of air was used to investigate only one of the five samples, at each time, that are part of this study. The theoretical findings of the proposed work were obtained using the well-known transfer matrix method in addition to MATLAB software. The results were computed corresponding to defect layer thicknesses of 200 and 700 nm under normal incidence to overcome the difficulties associated under oblique incidence corresponding to TE and TM polarized waves. We examined the performance of the proposed design by calculating the sensitivity, figure of merit, and quality factor values of the biophotonic sensor loaded with different samples. It was found that the sensitivity of our design reaches to a maximum of 428.6 nm/RIU corresponding to the defect layer thickness of 700 nm, when the cavity is loaded with an infected blood sample containing plasma only. This study successfully simultaneously examined the normal and infected blood samples containing the platelet, plasma, and hemoglobin components of blood.

Employing the Defective Photonic Crystal Composed of Nanocomposite Superconducting Material in Detection of Cancerous Brain Tumors Biosensor: Computational Study

The present research is focused on the externally tunable defect mode properties of a one dimensional (1D) defective photonic crystal (DPhC) for fast detection of cancerous brain tumors. The proposed design has utilized conventional 1D DPhC whose cavity is coated with SiO2 nanoparticles embedded in a superconducting material layer called a nanocomposite layer. The purpose of a nanocomposite superconducting layer is to induce temperature dependent external tuning of the defect mode inside PBG, in addition, to changing in the angle of incidence. The inclusion of a nanocomposite layer also improves the interaction between light and different brain tissue samples under examination. In order to investigate the transmission properties of the proposed structure the transfer matrix formulation in addition to the MATLAB computational tool has been used. First, we have chosen the optimized internal parameters at normal incidence to obtain the maximum performance of the design. Secondly, the effect of change in angle of incidence has been studied to further increase the performance by means of sensitivity, quality factor, the figure of merit and limit of detection to ensure external tuning of defect mode. After achieving a maximum value of sensitivity (4139.24 nm/RIU) corresponding to a sample containing a wall of brain tissues at θ = 63° we have further investigated the effect of change in temperature of nanocomposite layers on the position and intensity both of the defect mode inside PBG. We have found that the increase in temperature results in minute changes in sensitivity but a significant increase in the intensity of defect mode which is highly required in any photonic biosensing design. The findings of this study may be very useful for designing various bio-sensing structures which could have a significant and decisive role in the field of biomedical applications.