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Item Investigation of aluminum-based plasmonic devices for sensing applications in the near-infrared region(SPIE, 2024-03) Arora, Pankaj; Grover, NitikaWe present surface plasmon resonance-based sensing devices with Aluminum (Al) as the plasmonic metal in the near-infrared region and analyze the output performances in terms of higher sensitivity and the Figure of Merit (FOM). The optical characteristics of Al-based plasmonic sensors are explored using different interrogation modes (angle and wavelength). Biorecognition elements help to enhance the sensor’s performance, for which 2D nanomaterials are explored for the biofunctionalization of the top surface. In the end, we also present an Al-based plasmonic device that utilizes both prism and nanostructure-based configurations, and the same designed parameters for the device offer high sensitivity and FOM in both angle and wavelength interrogation.Item Meso-substitution controlled synthesis of bodipy–dpm conjugates: a pathway to tailored photophysical properties(2026) Roy, Aniruddha; Arora, Pankaj; Grover, NitikaWe show that the electronic nature of the meso-aryl substituent in 1,3,5,7-tetramethyl BODIPYs governs the reactivity of the 1,7-methyl (α-methyl) groups toward the Knoevenagel condensation. Reaction of pyrrole-2-aldehyde with electron-deficient 1,3,5,7-tetramethyl-meso-pentafluorophenyl and 1,3,5,7-tetramethyl-meso-4-nitrophenyl BODIPYs yields double condensation at the 1,7-methyl positions to give the corresponding bis(pyrrole) derivatives, whereas the electron-rich meso-tolyl analogue selectively undergoes single condensation at only one of the α-methyl groups under identical conditions. This substituent-dependent divergence extends to reactions with 1,9-diformyl-meso-aryl dipyrromethanes, enabling access to structurally distinct BODIPY–DPM conjugates. Reaction of 1,9-diformyl-DPM with meso-tolyl BODIPY selectively yields acyclic monosubstituted BODIPY–DPM conjugates, whereas the higher reactivity of meso-pentafluorophenyl BODIPY enables condensation between both 1,7-methyl groups and the two aldehyde functionalities of the diformyl-DPM scaffold, affording cyclic, porphyrin-like BODIPY–DPM frameworks. Notably, meso-pentafluorophenyl BODIPYs also undergo nucleophilic aromatic substitution of the para-fluorine atom by piperidine under the condensation conditions, as confirmed unambiguously by single-crystal X-ray diffraction. The resulting BODIPY–DPM and BODIPY–pyrrole conjugates exhibit pronounced bathochromic shifts (90–180 nm relative to parent BODIPYs), deep-red to near-infrared absorption (~670 nm) and emission (~750 nm), enlarged Stokes shifts, and strong intramolecular charge-transfer character. These features translate into efficient heavy-atom-free triplet formation, with singlet-oxygen quantum yields reaching up to 0.45. A representative conjugate (10) exhibits potent photodynamic activity in B16F10 melanoma cells with minimal dark toxicity (IC₅₀ = 0.95 μM). TD-DFT analysis indicates that excited-state twisting reduces ΔEST, thereby facilitating heavy-atom-independent intersystem crossing. Collectively, these results establish a robust molecular design framework for next-generation heavy-atom-free photosensitizers.Item Present status and prospects of MXene research(Springer, 2025-08) Arora, PankajThe MXene family has turned the tables in the materials field since its first reported work in 2011. This is primarily because of the unique underlying physical and chemical properties of these 2D nanomaterial. High metallic conductivity and greater robustness provided by MXene sheets have already given them a leading edge over transition metal dichalcogenides and graphite. The MXene family has now entered into a vast platform of sensor applications, wherein they are acting as a quintessential element. Incorporating MXene flakes above the metal substrates provides stronger corrosion protection, a large surface area, and increased hydrophilicity. Due to its stability in aqueous solutions, it is an active co-catalyst that captures the photo-generated charges utilized for sustainable hydrogen production. The most commonly used MXene, i.e., Ti3C2Tx, is reported to exhibit intense plasmonic behavior in the near to mid-infrared region. Strongly tunable optical properties of Ti3C2Tx, Nb2C, and Ta2C have also emerged as promising SERS substrates. The excellent mechanical strength and flexibility exhibited by crumpled MXene hybrid nano-coatings strive to act as electrodes, which were acquired for designing bendable high-performance supercapacitors. MXene films provide non-toxicity and hydrophilicity towards miniscule organisms, making them biologically compatible. By tailoring the properties using different MXene geometrical configurations (films, nanostructures, or 3D network layered structure), a plethora of applications in different domains are coming up. These applications also depend on the type of terminated groups utilized; for example, the –OH terminated groups have the strongest binding energy strength compared to their counterparts. So far, with over 30 MXene stoichiometric varieties reported, the future holds promising prospects of incorporating the MXene family into myriad real-world applications. The challenge lies in the experimental validation/realization of more and more MXene composites and the possibility of tweaking their intrinsic properties for large-scale commercial production. Therefore, the chapter attempts to gather the current state-of-the-art research carried out over the past few years to unravel the exquisite features of the MXene family and its composites. Consequently, the chapter will attempt to thoroughly analyze the present situation and future opportunities facing the MXene family in creating effective and long-lasting composites.Item Numerical study of a high-performance SPR sensor using ZNS and fluorinated graphene with consideration of experimental parameters(Springer, 2025-08) Arora, PankajA surface plasmon resonance (SPR)–based sensor, which consists of aluminum (Al) as a plasmonic metal and zinc sulfide (ZnS) as the dielectric layer, has been proposed in a modified Kretschmann configuration. An engineered layer of fluorinated graphene (FG) as a 2D nanomaterial has been included in the proposed configuration for better interaction with the bio-analyte. The proposed sensing device is designed using the transfer matrix and finite element methods for angle interrogation at a wavelength of 1550 nm, considering performance parameters like sensitivity, SPR linewidth, detection accuracy, and figure of merit (FOM). The multilayered engineered plasmonic sensor is found to have a maximum value of sensitivity (242.85°/RIU) and enhanced FOM (451.68 RIU−1). The effect of different glass substrates, plasmonic metals, dielectric materials, and 2D nanomaterials on the performance parameters has been studied. Finally, the engineered plasmonic biosensor {CaF2-Al (30 nm)-ZnS (2 nm)-FG} is used to detect different malaria stages by distinguishing healthy and malaria-infected red blood cells, showing its potential by significant improvement in sensitivity and FOM compared to many of the existing simulation-based SPR designs, indicating a strong potential for high-performance biosensing applications.Item Engineering dielectric and metallic metasurfaces for sensing applications in the near-infrared region(SPIE, 2024) Grover, Nitika; Arora, PankajDielectric and metallic metasurfaces are proposed to demonstrate the sensing applications in the near-infrared region under normal incidence light. The geometrical parameters of the proposed metasurfaces are designed using Rigorous coupled analysis under wavelength interrogation, and the results are verified using Comsol Multiphysics software. A layer of 2D nanomaterial (MoS2) is considered to increase the adsorption on the sensing surface. Aluminum-based metallic metasurfaces offer a sensitivity of 1100nm/RIU with a figure of merit of 250 RIU-1. The proposed metasurfaces are further used for the detection of cancer cells in human blood, and a red shift in the wavelength spectra is observed due to the increase in the refractive index.Item Ultrasensitive surface plasmon resonance-based biosensor for efficient detection of SARS-CoV-2 Virus in the near-infrared region(2024) Grover, Nitika; Arora, PankajThis work offers an ultra-sensitive multilayered surface plasmon resonance (SPR)-based biosensor that uses angular interrogation in the near-infrared (NIR) region to detect the novel coronavirus (SARS-CoV-2). The multi-layered biosensor consists of the bimetallic layer (Aluminum (Al) & Gold(Au)), a dielectric layer (MgF2), and an optimized number of 2D nanomaterial (MoS2) layers. The proposed SPR sensor is engineered using the transfer matrix and finite element methods to achieve high sensitivity, the figure of merit (FOM), and detection accuracy. The selection of plasmonic metal and optimization for the different layers have been proved crucial to improving the performance parameter of the proposed sensor. The biosensor configuration (Glass prism/Al/Au/MgF2/MoS2/sensing sample) is observed to exhibit the highest sensitivity of 372°/RIU, FOM of 1690 RIU-1, and detection accuracy of 4.54 degree-1 using the strong binding efficiency of the MoS2 layer and the high dielectric constant of the MgF2 layer. According to the investigation's findings, the proposed SPR-based biosensor exhibits excellent performance in the NIR region, demonstrating accurate real-time detection capabilities that will facilitate its use in field or clinical point-of-care testing applications.Item TiO2-FG-based plasmonic sensor with enhanced figure of merit for sensing applications: A numerical approach(Elsevier, 2025-09) Grover, Nitika; Arora, PankajA refractive index-based surface plasmon resonance sensor using a multilayer heterostructure in the Kretschmann configuration is proposed for the near-infrared region. In the proposed configuration, aluminum is used as a plasmonic metal, titanium dioxide is used as a dielectric layer, and a fluorinated graphene (FG) layer is used as a 2D nanomaterial to enhance the performance parameters. A thorough comparative study is conducted between popularly used titanium compounds: Titanium dioxide (TiO2) and Titanium disilicide (TiSi2). For the proposed SPR sensor, each layer is engineered and optimized on the grounds of linewidth, detection accuracy (DA), and Figure of Merit (FOM), which are the critical performance parameters. To this end, the geometrical parameters are calculated using the transfer matrix method and analyzed meticulously to find the optimum trade-off points. The proposed sensor is numerically tested efficiently to sense different concentrations of hemoglobin in human blood. For the angle interrogation technique at the wavelength of 1550 nm, the sensor provides an enhanced FOM of 462.8 RIU−1 and a DA of 4 degrees−1. Thus, the proposed design opens a broader window for bio-sensing applications because of the advantages TiO2 and FG layers offer in enhancing the sensing parameters.Item Investigation of 2D nanomaterials on MXene (Ti3C2Tx)-based aluminum plasmonic devices for biosensing in the near-infrared region(Springer, 2022-08) Arora, PankajIn this work, we have engineered Aluminum (Al)-based plasmonic devices with MXene (Ti3C2Tx) nanosheet to achieve both high sensitivities as well Figure of Merit (FOM) simultaneously for the wavelength of 1550 nm in the optical communication band. Since, studying 2D nanomaterials can provide quality collaboration for Ti3C2Tx, from their functionalization to application; Black Phosphorus, Graphene, fluorinated Graphene, and MoS2 are undertaken for this purpose. The effect of such 2D nanomaterials has been studied on both sensitivity and FOM for Ti3C2Tx-based engineered Al-plasmonic devices and a decent value of both sensitivity (119°/RIU) and FOM (340RIU−1) is achieved in the Kretschmann’s configuration. To demonstrate the bio-sensing application with the proposed plasmonic devices, the detection of protein solution concentration, based on the change in their refractive indices, is carried out. The proposed Ti3C2Tx-based Al-plasmonic devices show promising applications in the optical communication band, employing fluorinated graphene and MoS2 in the near-infrared region.Item Investigation of a highly-sensitive aluminum-based plasmonic device using antimonene for sensing applications(IOP, 2024-01) Arora, PankajAluminum (Al) has gained popularity for surface plasmon resonance-based applications due to its affordability and compatibility with CMOS technology at the nanoscale. Over angle-interrogation mode, plasmonic interactions occurring at the metal-dielectric junction, are the outcomes of the attenuated total internal reflection phenomenon. Modified Al-based Kretschmann configuration results in phase-matching conditions that are seen as resonant points in the reflection characteristics. In our work, we have engineered an Al-based plasmonic device utilizing Antimonene as a 2D nanomaterial for bio-sensing purposes in the Near-Infrared (NIR) spectral domain. The study investigates the performance of Surface Plasmon Resonance (SPR) based refractive index sensor using different 2D nanomaterials with an optimized Al thickness of 30 nm. A comparative analysis of Al-based Kretschmann configurations in the presence of Graphene, Black Phosphorus, MXene, and Antimonene is presented using engineered intermediate layers. It is observed that the Al-antimonene-based plasmonic device exhibits improved sensing parameters in the NIR optical window.Item Design and comparative analysis of aluminum-BiFeO3-based plasmonic device in the near-infrared region(Springer, 2024-05) Arora, PankajIn this work, a nano-plasmonic device based on Aluminum with BiFeO3 (BFO), as a multiferroic oxide with remarkable dielectric properties, is engineered using the transfer matrix method for implementation in an optical communication band for sensing applications. A comparative study is performed between different dielectric materials (e.g., BFO, Silicon, and Indium Phosphide), and the highest Figure of Merit (FOM) is achieved for the surface plasmon resonance sensor with BFO as the intermediate layer. To further increase the binding efficiency of the biomolecules with the sensing surface, a monolayer of 2D nanomaterial, namely Molybdenum disulfide, Graphene, MXene, and Fluorinated Graphene (FG), is added to the surface of the plasmonic device. After a rigorous analysis, FG is found to have the highest FOM of 334°/RIU and sensitivity of 125°/RIU. In summary, our work reveals potential applications for the proposed nano-plasmonic device based on Al-BFO configuration as a new type of supporting material with a monolayer of FG for enhancing biosensing activity.