Refractive Index Increment Research Articles

Optimization of photocurrent and surface wettability of new As10Bi30Se30Te30 thin films through annealing at different temperatures for optoelectronic applications

Group V-VI-based metal-doped double chalcogenides are essential in thermoelectric and suitable optoelectronic devices. The present investigation is based on optimising various optical, structural, and electrical behaviours of quaternary As10Bi30Se30Te30 films through thermal annealing at different temperature scales. The structural study by X-ray diffraction (XRD) exhibited the presence of various Bi2Se3, Bi2SeTe2, and Bi2Te3 phases in the annealed films. The crystallinity gradually enhanced after the annealing process. The microstructural modifications in the material have been confirmed through the Raman spectra. The elemental confirmation was verified from the energy dispersive X-ray (EDX) spectra, whereas the cross-sectional scanning electron microscopy (SEM) view showed the annealing-induced modifications in the films. The granular structure in the films is seen from the surface morphology study. The reduction of the energy gap from 1.36 ± 0.002 eV to 1.26 ± 0.001 eV upon annealing induced the increment in refractive index from 3.08 to 3.15. With annealing, the non-linear refractive index varied from 4.341x10−10 esu to 5.218 x10−10 esu. This indicates the narrowing of the bandgap and enhancement in the non-linear optical response of the material after the annealing process. The 3rd-order nonlinear susceptibility is also increased by annealing, thus making it suitable for nonlinear device applications. Annealing-induced surface change in the material enhances its surface wettability and makes it more hydrophilic. The linear enhancement in photocurrent with the voltage is ohmic and makes it suitable for various optoelectronic applications.

Characterizing Styrene Monomer and Oligomers by SEC/MALS/VISC/DRI

Worldwide polystyrene (PS) production in 2020 was approximately 27 million metric tons, distributed among many nations, making it one of the most heavily imported and exported chemicals. Commercially produced PS usually possesses a broad molar mass distribution, often with a substantial oligomeric component. The latter can significantly affect processing and end-use, in addition to having potentially hazardous health effects and to impacting the polymer’s export classification by regulatory agencies. Quantitation of the oligomeric region of polymers by size-exclusion chromatography with concentration-sensitive and/or static light scattering detection is complicated by the non-constancy of the specific refractive index increment (∂n/∂c) in this region, which affects the calculated amount (mass fraction) of oligomer in a polymer, molar mass averages, and related conclusions regarding macromolecular properties. Here, a multi-detector SEC approach including differential refractometry, multi-angle static light scattering, and differential viscometry has been applied to determining the ∂n/∂c of n-butyl terminated styrene oligomers at each degree of polymerization from monomer to hexamer, and also of a hexadecamer. Large changes in this parameter from one degree of polymerization to the next are observed, including but not restricted to the fact that the ∂n/∂c of the monomer is less than half that of PS polymer at identical experimental conditions. As part of this study, the individual effects of injection volume, flow rate, and temperature on chromatographic resolution were examined. Incorporation of the on-line viscometer allowed for accurate determination of the intrinsic viscosity and viscometric radius of the monomer and oligomers.

Polymer Characterization by Size-Exclusion Chromatography with Multi-Angle Light Scattering (SEC-MALS): A Tutorial Review.

This tutorial review presents the theory and application of SEC-MALS with minimal equations and a focus on synthetic polymer characterization, serving as an entry point for polymer scientists who want to learn more about SEC-MALS. We discuss the principles of static light scattering, outline its capability to generate absolute weight-average molar mass values, and extend its application to SEC-MALS. Practical elements are emphasized, enabling researchers to appreciate how values for , and are determined in an SEC-MALS experiment and how experimental conditions and input values, such as the specific refractive index increment ( ), influence the results. Several illustrative SEC-MALS experiments demonstrate the impact of separation quality on (as opposed to ), the appearance of contaminants in SEC chromatograms from sample preparation, the influence of concentration on data quality, and how polymer topology affects molecular weight characterization in SEC. Finally, we address practical considerations, common issues, and persistent misconceptions.

Characterization and Calibration of Cold-Alcohol Plasma Fractionation Intermediates by Kjeldahl Digestion and Digital Refractometry

Background Almost 80 years after implementation of the industrial ethanol fractionation process, based on the pioneering work of Edwin J. Cohn's research group, it has not lost its importance in providing life-saving biotherapies to patients. The focus has shifted from albumin, which was first used to treat intensive care patients, to immunoglobulin G preparations. Nowadays the latter enables effective, life-long treatment of patients suffering from immunodeficiencies. Ethanol concentration, pH, temperature, protein, and salt concentration are diligently varied during the Cohn fractionation process to finally yield fractions in which the main plasma proteins are enriched at adequate purity. Total protein concentration of the intermediates, probably not as important as ethanol levels and pH, has nevertheless an indisputable influence on the process’ performance Objectives Total protein measurement is therefore a valuable in process-control for versatile process performance monitoring. For this purpose, we investigated the application of analytical digital refractometry. Design For our pilot study, we used six consecutive batches of nine relevant intermediates covering Takeda's whole industrial-scale Cohn Fractionation process. Methods Total protein concentrations of the intermediates were measured with the method of Kjehldal to obtain reference data and digital analytical refractometry, using 10-kDa ultrafiltration to obtain a protein free permeate serving as a sample-specific blank. Results and Conclusions Specific refractive index increment dn/dc values, allowing the calculation of the total protein concentrations by refractive index measurement, were obtained for the Cohn Fractionation intermediates investigated. Thus, analytical digital refractometry, a simple, fast, and robust technique, was shown to be fit for this purpose.

Molecular characterization of a galactomannan extracted from Tara (Caesalpinia spinosa) seeds

Tara gum (TG) is a polysaccharide extracted from the seeds of a South American tree called Tara (Caesalpinia spinosa). TG is a galactomannan with many applications in the food industry, mainly as an emulsifier and stabilizer agent. In addition, it is also used in the paper and cosmetic industries. In the present study, we performed a molecular characterization based on chemical composition and physicochemical properties to understand the properties behind TG applications. TG was extracted and purified from Tara seeds distributed in different ecoregions of Bolivia. The monosaccharide composition analysis was determined by high-performance anion-exchange chromatography/pulsed amperometric detection (HPAEC-PAD). At the same time, their molecular characteristics, such as molar mass, root-mean-square radius, hydrodynamic radius, conformation, and densities, were studied by asymmetrical flow field-flow fractionation coupled to multi-angle light scattering refractive index (AF4-MALS-dRI), also the specific refractive index increment (dn/dc) was determined for the first time using AF4 for TG. The results revealed that the gum samples are galactomannans composed of mannose (Man) and galactose (Gal) in a ratio of 3.37 (Man/Gal), with an average molar mass range from 2.460 × 107 to 3.699 × 107 Da, distributed in a single population. The root-mean-square radius range from 260.4 to 281.6 nm, and dn/dc is 0.1454. The Kratky plots based on 14 scattering angles indicated that the conformation of all samples corresponds to random coil monodisperse, while their gyration radius/hydrodynamic radius ratio (ρ) is high. All these results suggest that the chains have a low branched density, consistent with the Gal/Man composition. To the best of our knowledge, we report for the first time an integrated physicochemical study of TG relevant to developing emulsifier and stabilizer formulations.

Phase change, tuning of optical and dielectric parameters in Bi/S-Se-Sb heterostructure film upon thermal annealing: An experimental and computational approach

The study is based on annealing-induced Bi diffusion into Se30S30Sb40 sites that bring modification in its linear-nonlinear optical, structural, and dielectric properties. The Bi/Se30S30Sb40 heterostructure film was annealed at 100,150,200 and 250 °C. The Bi2Se3 and Sb2Se3 phase formation was confirmed from the X-ray diffraction as well as from the Raman study. The morphology has been studied by the field emission scanning electron microscopy images with increased particle size upon annealing. The uniformity and homogeneity of the film were noticed from the energy dispersive X-ray analysis elemental mapping. The bandgap decreased from 1.461 eV (as-prepared Bi/Se30S30Sb40) to 1.258 eV (250 °C annealed) with an increment in static refractive index from 2.864 to 3.114 which was noticed from the optical study. The linear optical parameters were tuned with annealing conditions and such changes were understood from the concept of density of states and defects in the film. The increase in dielectric loss factor and decrease in quality factor with annealing is accompanied by the increase in both electronic and optical conductivity. The plasma frequency decreased and optical electronegativity reduced from 1.728 (as-prepared Bi/Se30S30Sb40) to 1.692 (250 °C annealed) with annealing. The value of 3rd-order nonlinear susceptibility and non-linear refractive index gets almost doubled (i.e. 1.838 × 10−11 to 3.913 × 10−11 esu and 2.419 × 10−10 to 4.735 × 10−10 esu respectively) with annealing with an increase in the nonlinear absorption coefficient. The hydrophilic nature of the films with annealing was observed from the surface wettability study. The computational study by density functional theory provided the necessary idea for structural and physical parameters of the films.

Determination of refractive index increments of PMMA particles dispersed in liquid phase

The refractive index increments of poly(methyl methacrylate) (PMMA) particles with sizes ranging from submicron to several microns were determined by measuring different concentrations of the solution and using a refractometer and microbalance calibrated by accurate traceability source. Conventionally, it was common to measure only the difference in refractive index between solvent and solution using a Bryce-type cell system, but it is difficult to perform traceable calibration since there is no reference material for refractive index increment. In this paper, we accurately quantify the refractive index increment by making individual measurements of the solvent and solution refractive indices, respectively, using Abbe-type refractometer. In addition, an uncertainty analysis was performed, and the results clarified the main factor of the variance in the refractive index increment measurements. The most important factor of variation of refractive index increment measurement is the measured apparent values at dilute concentration region including fluctuation of the system. This method was able to be applied to the determination of water content existing in particles. The percentage of the water content was determined using two different solvents, and the water content values were in good agreement within their uncertainties.

What is the diameter of a fibrin fiber?

BackgroundAltered fibrin fiber structure is linked to pathologic states, including coronary heart disease, ischemic stroke, and atherosclerosis. However, several different techniques are commonly utilized for studying fibrin structures, and comparison of results obtained using different techniques can be challenging due to lack of standardization. ObjectivesThis study provides a path toward standardization by comparing fibrin fiber diameters for a range of physiologic fibrinogen and thrombin concentrations using multiple different complementary experimental methods. MethodsWe determined fiber diameter using scanning electron microscopy (SEM), superresolution (stochastic optical reconstruction microscopy) fluorescence microscopy, and 4 commonly utilized turbidimetric approaches to determine the congruence between the results and the conditions under which each should be used. ResultsWe found that diameter values obtained using SEM and superresolution imaging agree within 10% for nearly all conditions tested. We also found that when a wavelength range of 500 to 800 nm was used for measurements and accounting for the wavelength dependence of the refractive index and specific refractive index increment, diameters obtained using the corrected Yeromonahos turbidimetric approach agree with SEM within 20% for most conditions. ConclusionWe performed a systematic, multitechnique survey assessing fibrin fiber diameters under a range of biochemical conditions. The similarity in the diameter values obtained using SEM and superresolution imaging suggests that drying and fixation during SEM sample preparation do not dramatically alter fiber cross-sections. Congruence, under certain conditions, between diameter values obtained using SEM, superresolution fluorescence imaging, and turbidimetry demonstrates the feasibility of a fibrin diameter standardization project.

Synthesis and molecular structure of highly compact star-like poly(methyl methacrylate) and poly(butyl methacrylate)

Poly(methyl methacrylate) and poly(n-butyl methacrylate) highly dense star-like polymers with a varied number and length of arms were prepared by the arm-first group transfer polymerization. The work is focused on the detailed characterization of the molecular structure and dilute solution properties of star-like polymers. The refractive index increment of the star-like polymers was compared with that of corresponding linear homopolymers. The prepared polymers were characterized by size exclusion chromatography coupled with a multi-angle light scattering detector and an online viscometer. Except for the commonly used molar mass, root mean square radius, and intrinsic viscosity, the obtained data also allowed the determination of the distribution of the arms per molecule, the calculation of the average number of arms per molecule, and the determination of the molar mass dependency of the draining factor. The relation between the number of arms per molecule and molar mass was estimated using various theoretical equations and compared with the true values obtained by the division of the slice molar mass by the molar mass of arms.

Formation of Waveguide Layers on the Surface of K8 Glass Produced by Thermoradiation Ion Exchange

The low-temperature heat treatment of K8 glass is carried out at temperatures of 350–500°C in alkaline melts of NaNO3 and CsNO3 salts in the field of gamma radiation from the 60Co source at the dose rate of 3000 R/s and also outside the field. Under the influence of thermoradiation treatment due to the @ ↔ @ ion-exchange diffusion, mechanical compressive stresses are created in the surface layer of the glass, which lead to the formation of a waveguide layer of the given thickness and an increase in the refractive index (RI) increment, the number of waveguide modes, and the depth of the waveguide layer.

Do conformational changes contribute to the surface plasmon resonance signal?

Surface plasmon resonance (SPR)-based biosensors are widely used instruments for characterizing molecular interactions. In theory the SPR signal depends only on mass changes for interacting molecules of same chemical nature. Whether conformational changes of interacting molecules also contribute to the SPR signal is still a subject of lively debates. Works have been published claiming that conformational changes were detected but all factors contributing to the SPR signal were not carefully considered, in addition to often using no or improper controls. In the present work we used a very well-characterized oligonucleotide, the thrombin-binding DNA aptamer (TBA), which upon binding of potassium ions folds into a two G-tetrad antiparallel G-quadruplex structure. All terms contributing to the maximal expected SPR response, Rmax, in particular the refractive index increment, RII, of both partners and the fraction of immobilized TBA target available, ca, were experimentally assessed. The resulting Rmax was then compared to the maximal experimental SPR response for potassium ions binding to TBA using appropriate controls. Regardless how the RIIs were measured, by SPR or refractometry, and how much TBA available for interacting with potassium ions was considered, the theoretical and the experimental SPR responses never matched, the former being always lower than the latter. Using a straightforward experimental model system and by thoroughly taking into account all contributing factors we therefore conclude that conformational changes can indeed contribute to the measured SPR signal.

Sensitivity enhanced tunable plasmonic biosensor using two-dimensional twisted bilayer graphene superlattice

Abstract This study theoretically demonstrated an insight for designing a novel tunable plasmonic biosensor, which was created by simply stacking a twisted bilayer graphene (TBG) superlattice onto a plasmonic gold thin film. To achieve ultrasensitive biosensing, the plasmonic biosensor was modulated by Goos–Hänchen (GH) shift. Interestingly, our proposed biosensor exhibited tunable biosensing ability, largely depending on the twisted angle. When the relative twisted angle was optimized to be 55.3°, such a configuration: 44 nm Au film/1-TBG superlattice could produce an ultralow reflectivity of 2.2038 × 10−9 and ultra-large GH shift of 4.4785 × 104 µm. For a small refractive index (RI) increment of 0.0012 RIU (refractive index unit) in sensing interface, the optimal configuration could offer an ultra-high GH shift detection sensitivity of 3.9570 × 107 µm/RIU. More importantly, the optimal plasmonic configuration demonstrated a theoretical possibility of quantitatively monitoring severe acute respiratory syndrome coronavirus (SARS-CoV-2) and human hemoglobin. Considering an extremely small RI change as little as 3 × 10−7 RIU, a good linear response between detection concentration of SARS-CoV-2 and changes in differential GH shift was studied. For SARS-CoV-2, a linear detection interval was obtained from 0 to 2 nM. For human hemoglobin, a linear detection range was achieved from 0 to 0.002 g/L. Our work will be important to develop novel TBG-enhanced biosensors for quantitatively detecting microorganisms and biomolecules in biomedical application.

Cubic to pseudo-cubic tetragonal phase transformation with Mg, Ca, and Be doping and its impact on optoelectronic, elastic and mechanical properties of SrHfO3

The structural, optoelectronic, elastic and mechanical properties of pure, Ca-, Mg-, and Be-doped SrHfO3 have been computed with CASTEP code based on density functional theory. The structure of SrHfO3 remains cubic with 1.40% doping concentration of Ca, Mg and Be whereas it is altered in pseudo-cubic tetragonal at the doping concentration of 4.22% and 7.04%. Reduction in the electronic band gap is observed in all the doping concentrations. For detailed explanation of electronic band gap reduction density of states (DOS), partial DOS and elemental partial DOS have also been computed. DOS plays a very meaningful role in understanding the behavior of band gap at different doping. The impact of dopants on the optical properties of pure SrHfO3 indicates the increment in refractive index (n), absorption (I), Loss function (L) and extinction coefficient (k) as well. For both cubic and tetragonal structures our compound shows mechanical stability in all doping percentages of Ca, Mg and Be other than the 1.40% of Mg and Be for cubic geometry. Over and above that to examine the mechanical properties of material like ductility and brittleness we have also computed the different characteristics such as Bulk modulus (B), Shear modulus (G), G/B ratio, Cauchy Pressure (CP) and Anisotropic factor (A). Interestingly, the material is purely ductile on all concentrations of Ca, Mg, and Be and shows brittleness only at the doping concentration of 1.40% of Ca.

Investigation of refractive index increment with crystallin protein aggregation.

In camera-type eyes, the lens is responsible for focusing light that is necessary for vision. The eye lens is composed of transparent and highly concentrated crystallin proteins. Post-translational modifications in crystallin proteins lead to protein aggregation and cataract formation, the leading cause of blindness worldwide. When light travels through an interface, it bends or refracts. The refractive index increment, dn/dc for proteins can be predicted based on its amino acid sequence. The experimentally measured refractive index increment for wild type βγ crystallin's has previously been shown to significantly deviate from the predicted values. Accurate refractive index increment values are important for data analysis in protein aggregation. This study looks at protein aggregation states and serves to further investigate discrepancies between predicted and measured refractive index increments by looking at a series of βγ crystallin's with differing amounts of deamidation mutations using multi-angle light scattering.

Numerical simulations of plasmonic properties of spherical gold nanodisks using T-matrix method: impact of geometry parameters on the sensitivity to the dielectric environment and the field enhancement

Simulations using the transition matrix approach are implemented for spherical gold nanodisks (AuNDs) to obtain insights into their plasmonic properties. We systematically follow the correlation between the optical response of these nanostructures with their geometry parameters and the refractive index of the surrounding medium. Plasmon wavelengths linearly redshift with the diameter-to-height aspect ratio, which is consistent with measured data available in the literature, thereby ensuring calculation accuracy. The relative plasmon resonance shift to the relative increment of the medium refractive index is geometry-dependent and exhibits a linear correlation in which the estimated slope represents the plasmon resonance sensitivity. We confirm the strong dependence of the field enhancement factor on the geometry parameters of nanodisks. The relative contributions of scattering and absorption in the extinction spectra are determined. Simulations show that circular AuNDs have well-controlled optical characteristics that will provide great opportunities to achieve various plasmon-derived applications.

Measuring dn/dc for Polysaccharide Microgels of Varying Crosslinking Density

Static light scattering (SLS) is a powerful, noninvasive experimental method that yields the molecular weight (average molecular weight, Mw), the size (radius of gyration, Rg), and the interactions between the scatters (the second virial coefficient, A2). However, proper SLS measurements require determination of the specific refractive index increment (dn/dc) for the samples studied. While tables of dn/dc values are available for various substances, they are not generally available for microgel particles, which in our case are crosslinked chains of an amphiphilic polymer. This paper is focused on measuring dn/dc for microgel samples of varying crosslinking concentrations. Microgel dn/dc values were found to be different from the value of the parent polymer given in literature and found to have a temperature dependence as well as a crosslinker concentration dependence at higher crosslinker concentrations. Using the measured values of microgel dn/dc instead of tabulated parent polymer values on estimates of microgel Mw, Rg, and A2 highlights the importance of direct dn/dc measurements for samples studied by SLS.

Fractionation and Absolute Molecular Weight Determination of Organosolv Lignin and Its Fractions: Analysis by a Novel Acetone-Based SEC─MALS Method

Accurate and reliable structural characterization of technical lignins is still challenging and inhibits industrial utilization as only poor understanding of structure–property relationship is available. Especially, molar mass analysis of technical lignins is of paramount interest; however, the usage of conventional size exclusion chromatography (SEC) and synthetic polymer standards as a consequence of inaccessible lignin standards is predominantly found in academia. This leads to a huge discrepancy in molecular weight analyses of lignins between different laboratories and consequently to fragile comparability. In this study, organosolv (OS) lignin from beech wood was exemplarily used to develop and evaluate a new acetone–water-based SEC method with the ability to be coupled to an electrospray ionization-mass spectrometer (ESI-MS) or to a multi-angle light scattering detector (MALLS or short MALS). The eluent system used shows very good solubility for the lignins investigated and hence lowers the probability for molecular aggregation of lignin molecules in solution. Solvent fractionation in acetone–water mixtures was conducted to acquire molecular weight classes. The starting lignin (parent lignin) was initially dissolved in 80 wt % acetone–water. Various fractions of the parent lignin were produced by a stepwise reduction of the acetone content. Molecular weights based on narrow polyethylene glycol (PEG)/polyethylene oxide (PEO) standards and absolute molar masses by coupling SEC with MALS were obtained, and the drawback of using polymer standards is discussed in detail. At a lower acetone content, low-molecular-weight fractions were found. Additionally, the specific refractive index increments (dn/dc) were determined for the parent lignin and its fractions. The impact of dn/dc on the final molecular weight (MW) was evaluated considering the chemical composition obtained by nuclear magnetic resonance spectroscopy (NMR) analysis. Furthermore, light scattering revealed that the absorption behavior for this OS lignin is low and neglectable. This article proposes a new acetone-based analytical method for direct determination of absolute molar masses of OS lignin molecules.

Detection of the Butyl Acrylate–Vinyl Acetate (BA–VA) Copolymer in Soil Binders Using Gel Permeation Chromatography (GPC) and Nuclear Magnetic Resonance (NMR)

Dust palliatives are commonly used when airborne dust is problematic. Dry soils are treated with a mixture of polymers, such as butyl acrylate vinyl acetate (BA–VA), emulsified in water. Eventual spread through surface runoff or leaching may transport palliative away from the application area. This paper reports a novel method developed for the determination of BA–VA using gel permeation chromatography (GPC) and nuclear magnetic resonance spectroscopy (1H NMR) to provide qualitative and quantitative measurements allowing further investigation of polymer-based soil palliatives. The results showed that the average specific refractive index increments (dn/dc) for BA–VA copolymer in two dust palliatives were 0.055 and 0.038 mL/g. The masses of extracted BA–VA were 1400 and 2900 mg from these products. The corresponding limits of quantification (LOQ) for the extracted BA–VA polymer using a refractive index (RI) detector were 11.63 and 17.04 µg, respectively.

Mollusc Crystallins: Physical and Chemical Properties and Phylogenetic Analysis

The purpose of the present study was to perform bioinformatic analysis of crystallin diversity in aquatic molluscs based on the sequences in the NCBI Protein database. The objectives were as follows: (1) analysis of some physical and chemical properties of mollusc crystallins, (2) comparison of mollusc crystallins with zebrafish and cubomedusa Tripedalia cystophora crystallins, and (3) determination of the most probable candidates for the role of gastropod eye crystallins. The calculated average GRAVY values revealed that the majority of the seven crystallin groups, except for μ- and ζ-crystallins, were hydrophilic proteins. The predominant predicted secondary structures of the crystallins in most cases were α-helices and coils. The highest values of refractive index increment (dn/dc) were typical for crystallins of aquatic organisms with known lens protein composition (zebrafish, cubomedusa, and octopuses) and for S-crystallin of Pomacea canaliculata. The evolutionary relationships between the studied crystallins, obtained from multiple sequence alignments using Clustal Omega and MUSCLE, and the normalized conservation index, calculated by Mirny, showed that the most conservative proteins were Ω-crystallins but the most diverse were S-crystallins. The phylogenetic analysis of crystallin was generally consistent with modern mollusc taxonomy. Thus, α- and S-, and, possibly, J1A-crystallins, can be assumed to be the most likely candidates for the role of gastropod lens crystallins.

Hemoglobin detection in blood samples using a graphene-based surface plasmon resonance biosensor

In the proposed work, the detection of hemoglobin has been carried out using an SPR biosensor. The detection of hemoglobin is necessary because excessive concentration can cause severe disorders like anemia or polycythemia. The proposed device can detect hemoglobin concentration in blood samples. The performance of the proposed biosensor is numerically analyzed using the angle interrogation method. A hemoglobin increment of 6.1025 g/L caused by a refractive index increment of 0.001 in the blood samples in the sensing medium has been detected using an SPR biosensor. The proposed configuration consists of layers of bimetallic silver layers (45 nm and 7 nm), MXene (2D transition metal carbides, carbonitrides, and nitrides), graphene, and zinc oxide (ZnO), along with a sensing medium to analyze biomolecule. The MXene, graphene, and ZnO thickness has been taken as 0.998, 0.34, and 2 nm, respectively. The analysis of the proposed sensor has been carried out using the transfer matrix method. The sensitivity attained is 161 deg/RIU with other performance parameters computed: full-width half maximum of 2.37 deg, detection accuracy of 0.4219 deg−1, and figure of merit of 67.93 RIU−1 for two MXene and three graphene layers.