The absorption of light by two-dimensional arrays of homogeneous spherical and cylindrical nanoparticles in an aluminum oxide matrix under lattice resonance conditions is studied. A semi-analytical statistical method (SASM) based on the quasi-crystalline approximation of the theory of multiple scattering of waves is used to model the optical properties of arrays of spherical particles with different types and degrees of order. A numerical finite element method (FEM) is employed to model the optical properties of perfect lattices of cylindrical particles. The calculation results for highly ordered imperfect lattices of spherical particles are in excellent agreement with the FEM data for perfect lattices of such particles. The spectral dependences of the absorption coefficient of the arrays on the spatial organization, degree of order, size, shape, and concentration of silver, gold, cadmium selenide, and MAPbBr3 perovskite particles are presented.

The effect of reactor neutron irradiation on Raman scattering spectra and electron spin resonance (ESR) signals of CVD monocrystalline diamond films is studied. The presence of superparamagnetic clusters of spin radicals (ferrons) — regions of magnetic ordering of uncompensated electron spins (g-factor ≈4.65) in an external magnetic field — is revealed for the first time in neutron-irradiated (fluence 3 ꞏ 1018 cm–2) diamonds. It is established that thermal annealing at 400 °C for 1 h drastically reduces the ESR signal intensity of spinradical associates of radiation defects, while approximately doubles the amplitude of the ESR signal from single paramagnetic centers and narrows its linewidth by a factor of ≈4.6. Raman spectroscopy data indicate partial recovery of the crystal structure of diamond due to the annealing of both isolated radiation defects and nanoscale amorphized regions (ferrons). The types of defects responsible for the formation of ferrons in diamonds as a result of their irradiation with reactor neutrons are discussed.

New nontrivial sub-Doppler absorption resonances caused directly by steady-state optical pumping of atoms by evanescent radiation in thin cells with a rarefied gas medium were theoretically established and studied. The dependences of these resonances on the intensity of such evanescent pumping and its penetration depth into the gas were analyzed. The possibility of detecting these resonances using previously developed, well-tested laser spectroscopy methods in such thin gas cells was substantiated. The established sub-Doppler resonances can provide important information about the mechanism of atom-surface interaction, as well as the properties of evanescent waves.

Laser-induced fluorescence (LIF) in 400–1000 nm wavelength range was studied using narrow-band laser radiation with the wavelength of 456 nm, resonating with 6S1/2→7P3/2 transition of Cs atoms. A T-shaped cell made entirely of technical sapphire, L = 1 cm in length, containing cesium vapors and capable of operating successfully at temperatures up to 450°C, was used. By recording the LIF signal, one can, estimate the amount of residual Rb vapor. The cesium-based cell can serve as an effective optical filter-converter, converting blue radiation to red one.

A simple, rapid, sensitive, and economical spectrophotometric method for the determination of erbium Er(III) ions using 3-[2-hydroxy-3-sulfo-5-nitrophenylazo]-pentadione-2,4 (R) in the presence of cetyltrimethylammonium bromide (CTMABr) as a cationic surfactant is described. Optimal complexation conditions (λopt, pHopt) for the homogeneous (Er(III)-R) and mixed-ligand (Er(III)-R-CTMABr) complexes are determined. Er(III)-R complex exhibits maximum absorption capacity at 417 nm, while Er(III)-R-CTMABr complex exhibits maximum absorption capacity at 426 nm. The molar absorption coefficient for the Er(III)-R complex is 0.92∙104, and that for Er(III)-R-CTMABr complex is 1.78 ∙ 104. The optimal pH value for Er(III)-R is 8, and for Er(III)-R-CTMABr complex it is 6. In the presence of CTMABr, the optical density of the complex solutions increases significantly, and the optimal pH value for complex formation shifts to the acidic region. The region of conformity to Bouguer–Lambert–Beer’s law is linear in the range of erbium concentrations from 1.34 to 5.30 μg/mL for Er(III)-R and from 0.62 to 6.65 μg/mL for Er(III)-R-CTMABr. The stoichiometric ratio of the components in the complexes was confirmed using isomolar series, Starik–Barbanel relative yield, and shift method. These methods confirmed the formation of complexes with component ratios of Er(III):R = 1:2 and Er(III):R:CTMABr = 1:1:1. The influence of certain foreign ions on the formation of Er(III) complexes was studied. The proposed method was used to determine trace amounts of Er(III) in volcanic rocks.

The spectral and luminescent characteristics of synthesized europium(III) dimethoxyphenylacetates with nitrogen- and phosphorus-containing ligands were studied. The electronic absorption spectra, luminescence excitation spectra, and the Stark structure of 5D0-7Fj (j = 0–2) electronic transitions in the low-temperature luminescence spectra of europium(III) dimethoxyphenylacetates were analyzed, and the quantum yield of the obtained complex compounds was determined. It was established that excitation energy is transferred to the europium(III) ion from both the dimethoxyphenylacetic acid levels and the levels of nitrogen-containing neutral ligands. The most thermally stable compounds were identified.

The optical and photoelectrical properties of active layers of various thicknesses fabricated using the D18 donor polymer and the Y6 acceptor were analyzed. Based on the absorption, photoluminescence, and external quantum efficiency spectra, the light-absorption efficiency and charge-carrier separation capability of the D18:Y6 blend were investigated. Our findings showed that for semi-transparent organic solar cells (ST-OSCs), the optimal active-layer thickness is 90 nm and ultimately, the D18:Y6 active layer is a highly efficient, stable and promising material for ST-OSCs.

Zinc oxide nanocrystals were synthesized in aqueous solutions at low temperatures, and their surface was coated with a thin film of the electrically conductive polymer poly(3-hexylthiophene) (P3HT) to form hybrid heterostructures. The synthesized nanostructures and hybrid heterostructures formed on their basis were subjected to heat treatment at various temperatures both in air and in vacuum (10–5 Pa). Changes in the optical properties of nanostructures and hybrid heterostructures after heat treatment were studied. Upon annealing of ZnO/P3HT heterostructures in air, it was found that the emission band corresponding to 0-0 transitions dominates in the photoluminescence spectra. When the heterostructures were annealed in vacuum, the photoluminescence spectra were dominated by the emission band corresponding to defects in the ZnO and polymer. These emission bands showed that heat treatment of heterostructures based on ZnO nanocrystals in air and vacuum at 100°C resulted in an optimal state of the interface layer between ZnO and P3HT polymer.

The structure of a near-surface plasma formation and plasma spectra were experimentally studied under two-pulse laser action with radiation wavelengths of 1064 and 532 nm on an yttrium vanadate YVO4 target in air, depending on the time interval between laser pulses and their sequence. The dependences of laser plasma temperature on the parameters of paired laser pulses were established at power densities of q1064 = 3.1 ꞏ 109 W/cm2 and q532 = 2.7 ꞏ 109 W/cm2, respectively. It is shown that the optimal conditions for achieving the maximum temperature Te ~1 ~ 104 K are realized with the leading action of laser radiation pulses with wavelength of 1064 nm and a time interval between pulses of  ~6 μs, and the maximum electron density  ~Ne = 1.1 ꞏ 1017 cm–3 is achieved with a time interval of ~15 μs.

In a hollow cathode discharge, the plasma glow intensity (I), the electron energy distribution function (EEDF), the electron concentration (Ne), and the average electron energy (<u>) were measured as functions of the discharge current and the measurement location. It was found that near the hollow cathode, the EEDF shape depends significantly on the discharge current. At a current of 50 mA, it exhibits a bi-Maxwellian shape. As the current increases, a local maximum appears in the EEDF, the position and amplitude of which change with increasing discharge current. These changes lead to a linear increase in the average electron energy. The electron concentration increases linearly with current changes from 50 to 200 mA, after which the value of Ne ceases to depend on the discharge current 200–450 mA. The glow intensities of individual He atomic lines have a linear dependence on the discharge current.

Composites based on epoxy resin modified with silicon oxide nanoparticles were studied by spectral and physical-mechanical methods. The effect of the percentage of filler and the dose of Ɣ-radiation on the strength characteristics of composites was analyzed. The best mode of composites solidification is established, and optimal physical and mechanical characteristics are achieved at filler content of 1% and radiation dose of 50 kGy. Basic spectral criteria have been established to characterize the change in the physical and chemical structure of the composite under the influence of Ɣ-radiation. It has been shown that the appearance of bands in the IR spectra in 1710–1740 cm–1 range and the increase in their intensity with increasing radiation dose can serve as a spectral criterion for enhancing destructive processes in the polymer matrix.

The fluorescence of graphene quantum dots (GQDs) at various pH, temperature, and ionic strengths, as well as in the absence and in the presence of peroxidases was investigated. It was found that myeloperoxidase and the hypochlorous acid it produces cause GQD degradation in biological systems. The rate of substrate oxidation by horseradish peroxidase and myeloperoxidase was shown to decrease in the presence of GQDs. Fluorescence, biodegradation, and the ability to be functionalized make GQDs the promising components for theranostic platforms.

The feasibility of forming a dielectric material based on oxidized porous silicon and titanium oxide by depositing the latter onto porous silicon using a sol-gel method and subsequent high-temperature oxidation is demonstrated. The resulting dielectric material is characterized by an increased refractive index, making it promising for the creation of low-loss integrated optical channel waveguides in bulk microassemblies of electronic circuits with optical interconnects.

A model for forming a spatial-energy profile (SEP) of the visibility zone for an object stationary relative to the system is proposed. The duration of the photodetector’s strobe pulses (exposure time) is significantly shorter than the duration of laser pulses illuminating the objects. Analytical expressions are derived linking the characteristic distances (points) of the SEP in the visibility zone with the durations of strobe pulses and the uncontrolled technical delay, as well as the parameters of the laser pulses for different temporal shapes. Numerical calculations confirmed the validity of the obtained analytical expressions. It was established and experimentally confirmed that, when moving from the initial point of the visibility zone to the final point, the SEP, taking into account certain patterns, reproduces (displays) the temporal shape of the laser pulse, following from its beginning to its end.

Based on a comparison of experimental and theoretical IR spectra of six brassinosteroids differing in the configuration of the diol group (22,23) and the substituent at position 24, spectroscopic criteria are proposed for rapid discrimination between (22R,23R)- and (22S,23S)-stereoisomers. The criteria are validated by a combined theoretical calculation (molecular mechanics + CNDO/2) and is suitable for express screening of synthesized compounds and control of stereochemical purity without recourse to time-consuming techniques.

Triazoxide as a fungicide was experimentally characterized via the help of the FTIR, 1H/13C NMR chemical shifts and UV-Vis spectroscopies. Theoretical modeling was performed using the DFT/B3LYP/6- 311++G(df,pd) computational level. The correlation between experimental and computed spectral data was investigated. The conformational analysis was used to obtain the most stable molecular geometry. Computational studies were performed for the two most stable conformational forms (C1 and C2) of triazoxide. The vibrational frequencies and assignments helped to determine the molecular vibrational motions. The effect of electron delocalization within the π-systems of triazoxide on its molecular structure and some vibrational wavenumbers was uncovered. The computational NMR results were analyzed with the GIAO method. The intra-molecular electronic transitions corresponding to the UV-Vis wavelengths were elucidated with simulations of the HOMO/LUMO electron localizations. The electron densities within the occupied/unoccupied molecular orbitals were investigated with the density of states analysis.

This study systematically investigates the effects of configuration interaction (CI) on the photoionization of the 3s shell in argon atoms using relativistic multiconfiguration Dirac–Fock methods. To quantify both CI effects and electron correlations, four distinct computational models were employed: Model A (single-configuration), Model B (restricted configuration with valence excitations up to the 4p orbital), Model C (extended configuration with core–valence excitations up to the 4p orbital), and Model D (extended configuration with core–valence excitation up to the 4d orbital). The results demonstrate that Models C and D, which incorporate single and double excitations from core–valence electrons into the 4p and 4d orbitals, achieve excellent agreement with the experimental cross-sectional data. Notably, the angular asymmetry-parameter β exhibits pronounced energy-dependent behavior, with significant divergence observed between models employing restricted versus extended CI treatments. A detailed analysis was conducted to explore the variations in boundstate and continuum-state electron orbitals across different models, as well as their influence on the photoionization transition matrix elements. This work underscores the critical importance of accurately modeling core– valence electron correlations for reproducing both absolute cross sections and photoelectron angular distributions, particularly near ionization thresholds and the Cooper minimum. These findings provide valuable insights into the fundamental mechanisms governing photoionization processes and highlight the need for advanced theoretical frameworks to enable precise predictions in atomic collision dynamics.

The physical characteristics of several series of marble samples taken from different regions of Morocco were experimentally determined. These characteristics include optical, elemental, and crystalline properties. The marbles and stones analyzed exhibited a variety of colors, including gray, white, black, yellow, and brown. For reference purposes, three white marble samples from Carrara, Italy; Drama; and Kozani, Greece were studied under the same conditions. A white marble sample from the 18th-century Moulay Ismail Mausoleum in Meknes was also studied under the same conditions. Using optical absorption spectroscopy, we identified bands attributed to ferrous and ferric ions (Fe2⁺ and Fe3⁺), which play a fundamental role in marble coloring. Other bands alongside long wavelengths were identified in accordance with crystalline and elemental studies and attributed to carbonates. Electron paramagnetic resonance (EPR) spectra revealed varying concentrations of Mn2⁺ ions in all the marbles studied. EPR lines attributed to Fe3⁺ ions distinguished ions resulting from Ca²⁺ substitution in the calcite lattice from those in iron oxides, clay minerals, and silicates. These identified ions are considered chromogenic elements responsible for the marbles' coloration.

This work describes the development of a fluorescence sensor based on citrate-reduced gold nanoparticles (GNPs) conjugated with 5-aminofluorescein (5AF) using EDC/NHS chemistry to create GNP@5AF nanoparticles. These nanoparticles were used to detect tryptamine (TRYP) by measuring changes in fluorescence intensity upon incubation with various TRYP concentrations. The sensor showed efficient fluorescence quenching with good linearity and a detection limit of 4 ng TRYP. The sensor’s applicability was tested in biological and food samples. In cheese and banana samples, a linear fluorescence enhancement allowed quantitative determination of TRYP within certain concentration ranges (2–10 ng in cheese and 2–16 ng in banana). However, nonlinear responses in other matrices limited the method’s broader application. Interference studies indicated that GNP@5AF had a high selectivity for TRYP compared to other amine-containing molecules. Overall, the GNP@5AF sensor offers a simple and sensitive fluorescence-based method for detecting tryptamine, with potential for food safety monitoring. The study suggests that further optimization with selective ligands could improve sensor performance and analytical robustness.

Aquilaria malaccensis, a highly endangered species valued for its fragrant resin, faces significant threats from over-harvesting. This study presents a conservation-oriented method for producing agarwood metabolites using a standardised in vitro callus proliferation protocol and solvent-based FTIR spectral profiling. FTIR analysis identified functional groups in ethanol, methanol, ethyl acetate, acetone, and petroleum ether extracts from both in vivo plants and in vitro callus. Callus extracts exhibited higher intensity and a greater diversity of sesquiterpenoid-related functional groups. Ethanolic and methanolic extracts from both sources exhibited strong O-H and N-H stretches (3366 and 3400 cm–1), while callus extracts displayed unique peaks such as C=O (1076 cm–1), C=N (1076 cm–1), and C=C=C (1956 cm–1), indicating oxidised and nitrogenous sesquiterpenoids. Ethyl acetate and petroleum ether extracts demonstrated strong C-H stretching and bending vibrations at 2920, 1460, and 778 cm–1, characteristic of long hydrocarbon chains in resinous compounds. Notably, ethyl acetate extracts from callus also indicated nitrogenous and aromatic sesquiterpenoids. Acetone extracts revealed aromatic and amine-related peaks at 1509, 1400, and 1056 cm–1. These findings highlight the enhanced biosynthetic potential of callus cultures. This approach reduces reliance on wild populations, preserves the product’s biochemical integrity, and offers an eco-friendly alternative for pharmaceutical applications.

Constructing heterojunctions is important for improving the photocatalytic performance of materials. In this study, porous Fe2TiO5 was prepared via a sol-gel method, and CuS was grown in situ on its surface through a hydrothermal process, thereby successfully synthesizing CuS/Fe2TiO5 heterojunction composites. The CuS/Fe2TiO5 composites were characterized via X-ray diffraction (XRD), transmission electron microscopy (TEM), UV-visible diffuse reflectance spectroscopy (UV-Vis), and Brunauer–Emmett–Teller (BET) analysis. The results indicated that CuS is uniformly loaded on the surface of Fe2TiO5, with lattice spacings of 0.3550 and 0.2972 nm corresponding to CuS and Fe2TiO5, respectively, and no impurity phases were observed. Heterojunction construction induced distortion of the TiO6 octahedra at the interface, resulting in the emergence of a new absorption peak in the ultraviolet region. Among the samples, the 20 wt.% CuS/Fe2TiO5 (denoted as 20CuF2) composite exhibited a specific surface area (SBET = 6.17 m²/g) between those of CuS (SBET = 4.87 m²/g) and Fe2TiO5 (SBET = 7.71 m2/g). Its band gap was tuned to 1.78 eV, and the photoluminescence intensity was significantly reduced. A CuS/Fe2TiO5 heterojunction composite was applied to facilitate the degradation of rhodamine B (RhB), achieving a degradation efficiency of 91.8%. The heterojunction catalysts developed in this study enable the effective degradation of pollutants in wastewater, providing a feasible technical reference for catalyst development and application.Hohhot, Inner Mongolia Autonomous Region

A green, stability-indicating UV-spectrophotometric method was developed and validated for the quantification of vanillic acid (VA) in bulk and niosomal formulations within a Quality by Design (QbD) framework. This method utilises a phosphate buffer (pH 6.8) as an eco-friendly solvent, in accordance with the principles of green analytical chemistry. Key analytical variables, such as sonication time and scanning interval, were optimized using a Design of Experiments (DoE) approach to enhance precision and robustness. The optimized method exhibited a maximum absorbance at 251 nm with excellent linearity over a concentration range of 2–16 µg/mL (R2 = 0.999). Validation according to the ICH Q2(R1) guidelines demonstrated high accuracy (recoveries between 99.65–101.41%), precision (RSD < 2%), sensitivity (LOD = 0.229 µg/mL; LOQ = 0.694 µg/mL), and robustness under variable conditions. Forced degradation studies in acidic, basic, oxidative, and photolytic environments confirmed the stability of the method. The developed method was successfully applied to quantify VA-loaded niosomal formulations, yielding an entrapment efficiency of 82.76%. Greenness assessments (AGREE = 0.82; AGREE prep = 0.80) confirmed the sustainability of the method. Overall, this study establishes a novel, green, and QbD-driven analytical approach that offers reliability, regulatory compliance, and environmental responsibility for the routine quantification of VA in bulk and nanoformulations.

A new UV-visible spectrophotometric method using the first derivative has been established for the selective measurement of tyramine in fermented food samples, successfully minimizing interference from histamine. This method has been validated following ICH Q2(R2) standards, showing excellent linearity between 10 and 18 µg/mL, with a limit of detection (LOD) at 0.401 µg/mL and a limit of quantification (LOQ) of 1.217 µg/mL, confirming its sensitivity and dependability for routine testing. An evaluation of the method's environmental impact using AGREE (0.66), BAGI (62.5), and MoGAPI (74) tools revealed a favorable level of greenness, particularly regarding energy efficiency, minimal sample preparation, and safe preservation, despite certain less eco-friendly elements associated with methanol and trichloroacetic acid due to their harmful nature. In conclusion, this method offers a simple, accurate, and reproducible way to measure tyramine in fermented foods, providing important insights into environmental performance and supporting sustainable practices in food analysis.

A simple, accurate, and precise spectrophotometric method has been developed for the simultaneous determination of pseudoephedrine (PSE) and loratadine (LOR) in bulk and tablets. The method principally exploits the spectral characteristics of the two compounds to affect mathematical manipulation of Beer’s law. The approach in this method enabled the removal of the spectral interference from LOR at the wavelength for the determination of PSE. It was possible to determine pseudoephedrine in the presence of loratadine using two wavelengths (257 and 280 nm). Two calibration curves were established for the analysis. The first was constructed to quantify LOR in the mixture on the basis of its absorbance at 280 nm. The second calibration curve was developed to determine the concentration ratio (CR) between the components at 257 nm. This curve was obtained by plotting the absorbance ratio (AR) against the concentration ratio, defined as CR = [PSE]/[LOR]. The concentration of PSE was calculated using the equation: [PSE] = CREXP × [LOR]. The developed analytical method was statistically validated in accordance with ICH Q2 guidelines and yielded satisfactory results. The assay results, expressed as a percentage of the labeled claim, were found to be 99.97 ± 0.71% and 101.10 ± 1.32% for PSE and LOR, respectively. These findings demonstrate that the proposed method is suitable for routine quality control analysis of tablet formulations. The validity of the proposed method was confirmed through statistical comparison of the data with those obtained by a reference chromatographic method.

We aimed to develop a stability-indicating method for tenofovir disoproxil using first-order derivative UV spectrophotometry to achieve clearer separation of overlapping spectra and ensure reliable detection of the drug along with its degradation products. λmax was recorded at 231 nm, while the first-order derivative wavelength was selected at 244 nm. The method followed Beer–Lambert’s law in the concentration range of 35–60 µg/mL with an R2 = 0.9961, and methanol proved to be the most suitable solvent. The method was validated as per ICH Q2 (R2) guidelines, covering linearity, accuracy, precision, LOD, LOQ, and robustness. The results showed minimal variation, with RSD values below 2%, and a recovery range of 98–101%, confirming the method’s accuracy. Forced degradation studies under different stress conditions further demonstrated the stability of tenofovir disoproxil, supporting its reliability during formulation and market release. Thus, the method provides a dependable, precise, and economical analytical strategy for assessing the stability profile of tenofovir disoproxil and identifying its degradation products.

A simple and accurate spectrophotometric method was developed for the simultaneous determination of levodopa (LD), carbidopa (CD), and entacapone (ENT) in pharmaceutical formulations. Because of the extensive overlap among their absorption spectra, three chemometric techniques – Artificial Neural Network (ANN), Fuzzy Inference System (FIS), and Adaptive Neuro-Fuzzy Inference System (ANFIS) – were applied to extract quantitative information and resolve spectral interferences. The ANN model, optimized using the Levenberg–Marquardt (LM) algorithm, demonstrated excellent predictive performance, with a coefficient of determination (R2) of 0.9999 for all analytes. The corresponding mean recoveries were 100.25, 99.42, and 99.65%, and the root mean square error (RMSE) values were 0.02, 0.006, and 0.05 for LD, CD, and ENT, respectively. The FIS model produced R² values of 0.9996 (LD and ENT) and 0.9998 (CD), with mean recoveries of 99.06, 99.42, and 99.25% and RMSE values of 0.14, 0.018, and 0.13, respectively. The ANFIS model yielded R2 values of 0.9981, 0.9970, and 0.9983, mean recoveries of 99.09, 98.56, and 99.34%, and RMSE values of 0.19, 0.05, and 0.22 for LD, CD, and ENT, respectively. Statistical comparison with a reference high-performance liquid chromatography (HPLC) method using one-way analysis of variance (ANOVA) indicated no significant difference between the results (p > 0.05). These findings demonstrate that the proposed spectrophotometric–chemometric approaches provide reliable and cost-effective alternatives to chromatographic techniques for the routine quality control of multicomponent pharmaceutical formulations.

Enhancing the precision of quantitative analysis in calibration-free laser-induced breakdown spectroscopy (CF-LIBS) requires a thorough understanding of self-absorption correction techniques. This work introduces blackbody radiation referenced-particle swarm optimization (BRR-PSO) as a self-absorption correction technique. This method compares the measured spectral intensity to blackbody radiation using Particle Swarm Optimization (PSO) to enable quick self-absorption correction. Corrected spectral intensities are obtained by iteratively refining initial values using the PSO optimization technique. Experiments were conducted on alloy samples to verify the efficacy of this method. The results show that as compared to the traditional CF-LIBS methodology, the CF-LIBS with the BRR-PSO method significantly improves the mean relative error (MRE). The MRE decreased from a range of ~27.35–43.75% to ~5.14–7.86% for the six alloy samples. For Fe I, Mn I, Cr I, Mo I, C I, and Si I, the Boltzmann plot linear fit coefficient of determination (R2) increased from 0.9220, 0.8050, 0.8801, 0.7102, 0.9064, and 0.9146 to 0.9887, 0.9813, 0.9662, 0.9809, 0.9542, and 0.9459, respectively. By greatly increasing both quantitative analysis accuracy and adaptability, the CF-LIBS approach improved with BRR-PSO demonstrating a clear advantage over conventional CF-LIBS. This development makes CF-LIBS technology more dependable and adaptable for real-world analysis, which is crucial for extending its useful applications.

Hydrogen sulfide (H2S), a recognized toxic gas, has emerged as a key indicator of food spoilage and a potential threat to water safety. Herein, a new fluorescent probe PHZ was designed and synthesized for sensing H2S. When added to PBS (10 mM, pH 7.40) solution, the probe PHZ exhibited a remarkable “turnon” emission response at 450 nm producing a significant blue fluorescence. The probe PHZ demonstrated excellent selectivity and anti-interference performance in complex environments. It also exhibited good sensitivity for the detection of H2S; however, detection was limited to 0.23 μM. Moreover, the probe PHZ was successfully used for the detection of H2S in environmental water samples and monitoring food spoilage process. In summary, this study highlights the potential of fluorescent probes like PHZ for evaluating environmental water pollution and food freshness.

This paper deals with the birefringence and order parameter calculation of liquid crystalline (LC) materials like p-n-decyloxy (10OBA) benzoic acid with the incorporation of ZnO nanoparticles (NPs) in different low wt.% concentrations (0.5–2 wt.%). From the characterization techniques, it is evident that ZnO NPs in 10OBA results in significant changes in optical properties such as refractive index (RI), birefringence (δn) and order parameter (S). The observations suggest that, because of their larger size and higher dipole moments compared to the nematic LC molecules, ZnO NPs generate a higher torque. This torque facilitates the orientation of the LC molecules, leading to increased birefringence and improved ordering within the LC system. The order parameter values are calculated using four optical methods – Kuczynksi, Haller, Effective geometry, and Vuks – at a stabilized nematic region in the visible range at 435, 500, 570, and 635 nm wavelengths. The values of dispersive powers are also increased for the 10OBA with ZnO NPs in various concentrations. The results suggest that the materials can be used in liquid crystal displays and tunable lenses.