Fano resonance with asymmetric and sharp spectral features has recently been intriguing for refractive index sensing. In this study, we demonstrate a Fano resonance sensor that employs the coupling between a metal-insulator-metal (MIM) waveguide and a semi-ring resonator. The MIM waveguide has a three-ring resonator built in the center, and high-field confinement is observed due to the coupling of the two structures. The coupled structure's transmission spectrum exhibits three Fano resonance modes that are influenced by structure geometry and the surrounding medium's refractive index. The high-quality factor ( ) of mode 3 indicates that this sensor is suitable for use in optical sensing applications. To achieve maximum sensing performance, the parameters of the proposed structure are manipulated and different sensing parameters are computed. The sensor's estimated sensitivity of 3164.97 nm/RIU is equivalent to that of other Fano resonance sensors. Additionally, for plasmonic MIM sensors, the developed sensor achieves high values of and of 5420.99 and 5641.57 , respectively. The proposed high-sensitivity sensor could be an attractive choice for sensing applications because of its straightforward design and ease of fabrication. Also, the combination of very high sensitivity and FOM in a tiny and compact configuration is ideal for on-chip plasmonic nanosensors

We propose and analyze a novel plasmonic multi-resonator perfect absorber based entirely on an all-metal Cu grating structure for high-performance optical sensing applications. The design features a continuous Cu substrate with two identical grating exhibiting seven distinct narrowband resonances spanning the near-infrared region (1270–1990 nm) with absorption efficiencies exceeding 90%. With an ultra-narrow linewidth (FWHM = 0.0188 nm) and an outstanding Q-factor (≈ 10⁵), the highest-order resonance (P7) exhibits a perfect absorption value at 1991.312 nm, guaranteeing remarkable spectrum selectivity and sensing resolution. To enable tailored sensing capabilities, systematic studies reveal that adjusting geometric features such as the grating height and the spacing between gratings can precisely tune the resonance wavelength while maintaining strong absorption and narrow linewidths. Sensitivity analysis against refractive index variations in the surrounding medium indicates a high sensitivity (S ≈ 1991.311 nm/RIU), an outstanding figure of merit (FOM ≈ 1.06 × 10⁵), and a low detection limit on the order of 10⁻⁶ RIU. The absorber’s strong sensitivity to small changes in refractive index, including those caused by gas analytes such as air, helium, nitrogen, and carbon dioxide, highlights its promising potential for use in multiplexed and selective biochemical and gas sensing applications. The use of an all-metal configuration supporting multiple high-Q resonances is unique among current absorber designs. This structure combines simplicity, tunability, and multi-wavelength operation in a single material platform, o​f​f​e​r​i​n

Metamaterial perfect absorbers operating at resonance wavelengths have emerged as a promising platform for next-generation optical sensing technologies. In this study, we propose and investigate a high-performance plasmonic absorber designed for refractive index sensing in the infrared region, based on a Fabry–Perot resonance cavity. The structure consists of a thick gold layer acting as a reflective mirror and absorber, while carefully selected dielectric silicon strips are used to achieve optimal resonance coupling. The main innovation lies in integrating a Fabry–Perot resonance cavity with a plasmonic absorber to achieve near-perfect absorption and precise wavelength tunability. This approach improves the sensing accuracy and efficiency compared to traditional absorbers by leveraging strong resonance coupling and optimized material configuration. By varying the refractive index of the dielectric spacer material between the Fabry–Perot mirrors, the sensor demonstrates a clear and measurable shift in resonance wavelength. The proposed design achieves a high sensitivity of 993.03 nm/RIU, an exceptional quality factor of 1581.96, a figure of merit of 958.49 , and near-perfect absorption reaching 99.5 %. These results highlight a significant improvement in sensing performance compared to conventional designs and suggest strong potential for applications in highly sensitive metamaterial-based optical sensors. The proposed structure significantly enhances sensing performance by achieving a higher sensitivity, quality factor, and figure of merit compared to conventional plasmonic absorbers. These advancements make the design well-suited for real-world applications in optical biosensing, environmental monitoring, and infrared detection technologies.

Fluids are major fractionation agents in granitic systems because they partly control the behaviour and partitioning of elements, including rare metal, during the magmatic-hydrothermal transition and their subsequent redistribution during the later subsolidus stage. The exsolution of magmatic fluids from a volatile-saturated magma and their subsequent circulation commonly result in important textural and geochemical changes with primary magmatic features being entirely overprinted and earlier minerals chemically re-equilibrated. The changes documented herein serve as a basis for tracking the equilibration of a rare-metal granite with interacting fluids. The Mueilha F-Nb-Ta-REE-Y granitic system (Eastern Desert of Egypt) is composed of different facies such as the “red granite”, representing the main volume of the intrusion, and the “border facies”, occurring along the red granite south-western margin

A high resonance peak in the spectral response enables a highly sensitive mechanism for refractive index monitoring, enabling accurate detection of environmental changes. In this work, a new plasmonic structure that incorporates two periodic silver nanorods into a metal–insulator-metal (MIM) waveguide are proposed. Dual periodic silver nanorods in MIM waveguide form the basis of the innovative and straightforward plasmonic structure introduced by the suggested design, which has never been described before. Due to the periodic manipulation of silver nanorods, this arrangement offers a high-quality factor resonance and remarkable sensing capability, all while being tiny and straightforward to fabricate. A high-transmission resonance mode that is highly sensitive to the surrounding medium’s refractive index is supported by the cavity produced between these nanorods. The performance of this design using finite element method ($\text{FEM}$) simulations was examined, showing plasmon-induced transparency ($\text{PIT}$) effects and notable improvements in refractive index sensitivity. The sensor is comparable to the most sophisticated plasmonic sensors on the literature with a sensitivity of $1780\text{nm}\mathrm{/}\text{RIU}$. Additionally, the suggested design achieves an exceptional Quality factor ($\text{Q}-\text{factor}$) of 1537.96 and a Figure of merit ($\text{FOM}$) of 1537.39 $RI{U}^{-1}$. A wide range of refractive index (RI) sensing applications could benefit from the sensor’s high performance and straightforward production procedure.

In this work, a versatile compound, 4-cyano-1,6-dimethyl-8-phenyl-7,8-dihydroisoquinoline-3(2H)-thione (3) was synthesized and utilized as a starting compound for the preparaton of the title compounds. Thus, reaction of 3 with iodomethane, 2-chloroacetamide, ethyl chloroacetate, chloroacetonitrile or N-(benzthiazol-2-yl)-2-chloroacetamide by heating in ethanol containing sodium acetate, gave 3-unsubstituted or 3-substituted methylsulfanyl-7,8-dihydroisoquinoline-4-carbonitriles 4 or 6, 8, 10 and 16 respectively. The latter compounds (6, 8, 10 and 16) contain an active methylene group that adds easily to the carbonitrile group to build a thiophene ring, fused to an isoquinoline moiety, upon heating with sodium ethoxide in ethanol thus affording the corresponding 6,7-dihydrothieno[2,3-c]isoquinolines 7, 9, 11 and 17, in nearly quantitative yields. Compounds 9, 11 and 17 underwent further reactions with some reagents to give other 6,7-dihydrothieno[2,3-c]isoquinolines 12-15 and 3,4-dihydropyrimidothienoisoquinoline 18. All synthesized compounds were screened for their biological activity as bactericidal and fungicidal agents. Some of them showed promising antifungal activity.

A high-performance liquid chromatographic method (HPLC) with UV detection is described for determination of ceftriaxone sodium (CFX) and cefotaxime sodium (CFM) content in pharmaceutical industrial wastewater. These methods are based on the detection of these antibiotics via the formation of chelate complexes with Cu(II). The developed Liquid Chromatographic method offers symmetric peak shape, good resolution and reasonable retention time for both drugs. The removal percentage reached about 100 and 92.1% at pH 7.2 for CFX and CFM, respectively. In UV detection, the removal of the chelating antibiotics were based on forming of chelate complexes with Cu(II) which detected at λ_{max =} 253 and 244 nm for CFX and CFM, respectively. Linearity, accuracy and precision were found to be acceptable over the concentration range of 5.99–59.86 µg mL⁻¹ for CFX and 14.33–71.63 µg mL⁻¹ for CFM. The proposed method can be used for the quality control of industrial wastewater containing CFX and CFM.

Malachite green accumulation in water causes harmful effects. Biodegradation by microbes was the preferred technique used to remove dyes from wastewater. Thirty yeasts were investigated for their ability to remove 50 mg of dye and belonged to: Deboryomyces, Diutina, Papiliotrema, Rhodotorula, and Saccharomyces. Based on the decolorization index (DI) of the examined yeast on the solid medium, the decolorization activity may be classified as highest, moderate and low decolorization activity with DI 1.66-2.78, 1-1.64, and <1 respectively. Rhodotorula mucilaginosa AUMC13567, R. mucilaginosa AUMC13570, Saccharomyces cerevisiae 11688, R. mucilaginosa KR264902, S. cerevisiae C3, and Diutina rugosa AUMC13571 possess the highest decolorization percentages in broth media: 98.41%, 96.65%, 96.49%, 95.59%, 92.80%, and 92.22%, respectively. The decolorization rate is influenced by time, however, yeast cell optical density has no bearing on this rate. The Fourier Transform Infrared Spectroscopy Analysis (FTIR) results of MG before and after degradation indicate a reduction of peaks along the fingerprint region, which can be attributed to the loss of aromaticity of the metabolites, which also confirm degradation by yeast strains. The effect of malachite green dye and its degradation metabolites by five selected yeasts was studied on wheat (T. aestivum), sorghum (Sorghum bicolor), maize (Zea mays), and radish (Raphanus sativus) seed germination, and results show that the germination index of seeds in untreated malachite green solution was significantly low compared to its degradation metabolites by selected yeasts and yeast …