The direct synthesis of boron nitride nanotubes (BNNTs) via chemical vapor deposition (CVD) in high-temperature furnaces remains highly challenging due to difficulties in optimizing key experimental parameters such as synthesis temperature and catalyst composition. These challenges often result in uncontrolled growth behavior, adversely affecting the quality and yield of the BNNTs. In this study, colemanite was effectively utilized as a boron source for the high-yield synthesis of directionally aligned BNNTs. The synthesis was carried out using a CVD method that used a dual-catalyst system comprising Fe2O3 and MgO in conjunction with a silicon carbide template under high-temperature conditions. The resulting BNNTs were characterized using scanning electron microscopy and high-resolution transmission electron microscopy, as well as spectroscopic methods including Fourier-transform infrared spectroscopy, Raman spectroscopy, X-ray diffraction, and X-ray photoelectron spectroscopy. This innovative CVD strategy offers a cost effective and efficient way to produce high-purity BNNTs from colemanite, significantly expanding their potential for various applications.

This study used single-crystal X-ray diffraction, elemental analysis, infrared (IR) spectroscopy, theoretical nuclear magnetic resonance (NMR), and theoretical ultraviolet spectroscopy to characterize 3 newly synthesized crystalline compounds. Additionally, the nonlinear optical, highest occupied molecular orbital energies, lowest occupied molecular orbital energies, band gap, molecular electrostatic potential, and thermodynamic parameters of the 3 crystalline compounds were examined. The strong correlation between experimental IR spectra and theoretical NMR chemical shifts confirmed the accuracy of computational predictions. The molecular formulas of the 3 newly synthesized crystalline compounds, each containing different ligand molecules, were: C8H14O4·2(C6H4N2), C5H7N2·NCS, and Ni(CN)4·2(C5H7N2)·2(H2O) for compounds 1, 2, and 3, respectively. Crystallographic analysis showed that the compounds crystallize in the space groups P1̄, P21/n and C2/m, respectively. Their molecular packing is stabilized by a network of hydrogen bonds (C–H···O, O–H···N, N–H···N, N–H···S, O–H···N, and N–H···O) and noncovalent interactions (C–H···μ and μ···μ). Computational studies using Gaussian 03 and CrystalExplorer further elucidated their structural, magnetic, electrooptic, and electrochemical properties.

This study investigates the extraction behavior of Y3+ ions using a Multi-Dropped Liquid Membrane (MDLM) system that employs di(2-ethylhexyl) phosphoric acid (D2EHPA) as the carrier ligand. The focus is on the system's ability to transport ions between aqueous phases selectively. The extracted complex was analyzed spectrophotometrically via ultraviolet-visible (UV-Vis) measurements after complexation with 0.05% Arsenazo III. The aim of this study was to determine the influence of the optimum D2EHPA carrier concentration, together with the pH and temperature conditions of the donor and acceptor phases, on the system's extraction performance. Accordingly, a series of extraction experiments was performed at different D2EHPA concentrations, pH values, and temperatures to assess their combined effects on transport kinetics. The MDLM system achieved a maximum transport efficiency of 99.90% for Y3+ ions at a D2EHPA concentration of 0.0045 mol/L, with a corresponding extraction time of 160 min. The shortest transport time of 120 min was observed at a carrier concentration of 0.0075 mol/L, confirming the strong influence of carrier concentration on extraction kinetics. The calculated low activation energy of 31.446 kJ/mol suggests that the transport of Y3+ ions through the MDLM system into the organic phase containing D2EHPA is diffusion-controlled.

This study highlights the potential of organometallic carbonyl complexes as selective markers for biomolecules, enabling sensitive infrared (IR) detection. The regio- and stereoselective coupling of N-acetylhistamine, a histidine analogue, with the precursor complex 1 [Fe(CO)3(1,4-η5-N-pyridiniocyclohexa-1,3-diene)] BF4 affords the labeled complex 3 [Fe(CO)3(1,4-η5-N-acetylhistaminocyclohexa-1,3-diene)]. X-ray diffraction (XRD) confirms the exo stereochemistry and reveals a rigid, well-defined architecture. IR and 1H nuclear magnetic resonance spectroscopic studies combined with IR-monitored acid-base titration demonstrate the complex's stability in aqueous media between pH 5 and 8, alongside a modest increase in basicity relative to the free ligand. These findings establish the Fe(CO)3 moiety as a robust platform for selective labeling of peptides and proteins, paving the way for targeted applications in bioorganometallic chemistry and spectroscopic imaging.

Human serum albumin (HSA) is a ubiquitous, multifunctional protein responsible for the systemic distribution of both endogenous metabolites and exogenous pharmaceuticals. Its inherent properties, particularly its ability to seep into tissues and its multiple ligand-binding sites, have rendered HSA an attractive vehicle for nanoparticle-based drug delivery systems, particularly for cancer targeting. In this study, we present high-resolution crystallographic data revealing two distinct dimerization patterns of HSA (Protein Data Bank [PDB] ID: 9V61) obtained under high-concentration crystallization conditions, along with results from dipyridamole docking. Both dimer types demonstrate extensive interface areas and a significant number of electrostatic interactions. Comparative analysis with a previously reported dimer structure (PDB ID: 3JQZ) and other high-interface-area structures (PDB ID: 5Z0B, PDB ID: 8CKS) indicates similarities in contact regions but unique residue-level differences in bonding interactions. Interface surface area distribution and space group histograms further support the rarity and potential physiological relevance of the identified dimer forms. Importantly, these dimer configurations do not disrupt Sudlow’s drug-binding sites, as the dipyridamole docking analysis shows strong affinity for sites I and III without affecting their utility in engineered drug delivery. Our findings open new avenues for structure-based mutagenesis and nanoparticle design strategies centered on HSA dimerization dynamics.

In this work, electrochemical biosensors utilizing tyrosinase (Tyr) for the detection of the nonselective beta-adrenergic agonist isoproterenol (ISO) are presented. Three different configurations for immobilizing Tyr on a graphite electrode (GE) are compared: (1) GE modified with poly(diallyldimethylammonium chloride) (PDADMAC), PDADMAC/Tyr/GE; (2) PDADMAC combined with iridium nanoparticles (IrNPs) in a stepwise preparation, resulting in PDADMAC/IrNPs/Tyr/GE; and (3) a composite of PDADMAC and IrNPs mixed with Tyr at a 1:1 (v:v), forming PDADMAC/(IrNPs-Tyr)/GE. Surface morphology was characterized using scanning electron microscopy (SEM). Cyclic voltammetry (CV) and amperometry were applied to characterize the biosensor's performance. Within the linear range of 5 μM to 211 μM, the biosensor PDADMAC/Tyr/GE exhibited a limit of detection (LOD) of 1.4 μM and a limit of quantification (LOQ) of 4.1 μM. PDADMAC/IrNPs/Tyr/GE displayed improved sensitivity with an LOD of 0.9 μM and an LOQ of 2.8 μM. The configuration PDADMAC/(IrNPs-Tyr)/GE demonstrated the best performance with an LOD of 0.3 μM and an LOQ of 0.8 μM. The slopes (0.0147 μA/M, 0.0096 μA/M, and 0.0031 μA/M for PDADMAC/(IrNPs-Tyr)/GE, PDADMAC/IrNPs/Tyr/GE, and PDADMAC/Tyr/GE, respectively) of the concentration dependencies for the three sensor modifications (which represent the analytical sensitivity) demonstrate the achieved enhancement of analytical performance by IrNPs. Furthermore, the biosensor's ability to detect ISO in the presence of potential interferences, such as ascorbic acid, uric acid, and paracetamol, was assessed. Additionally, we demonstrated the biosensor's potential to detect ISO in diluted spiked human serum samples.

Gold is abundant in nature, however, precise and reliable analytical methods for its detection are required stemming from its increasing prevalence in environmental, biological, and industrial systems, as well as the growing interest in understanding its function in living organisms and its effects on human health. This study investigates the use of biogenically synthesized silver nanoparticles (AgNPs) for the preconcentration and determination of gold ions prior to determination by UV-Vis spectrophotometry. AgNPs were synthesized by reducing silver nitrate through the use of an apricot kernel extract as both reducer and stabilizer agent. The colloidal yellowish AgNPs interacted with gold ions, leading to a distinct color change and a considerable decrease in the surface plasmon resonance (SPR) intensity at 415 nm in the UV-Vis absorption band, indicating a highly sensitive and selective colorimetric detection of gold ions. Under optimized conditions, the proposed method achieved satisfactory limit of detection (LOD) and limit of quantification (LOQ) values of 2.9 and 9.7 mg/L, respectively. A matrix matching calibration strategy was used to enhance quantification accuracy, resulting in satisfactory percent recoveries from waste mud samples (88–112%). Overall, the results validated the developed method as a green, simple, rapid, and accurate analytical approach to the determination of gold.

Paclitaxel (Pac) is an important anticancer bioactive compound, and the availability of an accurate and robust analytical method for its quantification is of utmost importance. In this investigation, a novel, direct, and reliable spectrophotometric method has been proposed for the estimation of Pac via a complex formation reaction with osmium (Os). The method was based on the reaction of Pac with Os tetroxide, which produced a yellowish-brown complex. The resulting complex is soluble in water and displays a maximum absorption peak at 482 nm. The reaction conditions, including reactant concentration, pH, temperature, and reaction time, were optimized to obtain the best spectrophotometric response. A thorough method validation study was conducted, demonstrating that the calibration curve is linear over the concentration range of 1.0-55 μg/mL and follows Beer's law, with a molar absorptivity of 3.01 × 10-4 L/mol-1.cm-1. The limit of detection (LOD) and limit of quantitation (LOQ) were 0.0098 and 0.0328 μg/mL, respectively. The recovery values were planned and found to be 98.70%-100.23%. At the same time, the precision values (represented by relative standard deviation percent [RSD%]) were better than 0.81% (in injections) and 1.859% (in biological fluids), depending on the Pac concentration. The suggested method was successfully applied to estimate Pac in a pharmaceutical formulation (as injections) and in spiked biological fluids (serum and urine), with results showing good accuracy and precision compared to the reference method.

Novel coumarin-triazole-coumarin dyads were synthesized and characterized, and their α-glycosidase inhibitory activities were evaluated spectrophotometrically. Compound 4e exhibited the most pronounced inhibitory effect, with an IC50 value of 38.98 ± 0.77 μM. The IC50 values for 4d and 4a were 93.55 ± 1.70 μM and 95.04 ± 3.55 μM, respectively. The Lineweaver-Burk plot showed that 4e inhibited α-glycosidase in a mixed type. In addition, the K i value obtained from the Dixon plot was 19.95 ± 0.15 μM for α-glycosidase.

Hydrazone chemistry has become important and plays a key role in the development of organic compounds. Hydrazones can be useful pharmacophores for creating novel derivatives, owing to their broad range of activities. In this study, a series of N-((2-hydroxy-3-(2-(substitutedbenzylidene)hydrazine-1-carbonyl)naphthalen-1-yl)(3-nitro-phenyl/3,4-dimethoxyphenyl)methyl)acetamide derivatives were prepared, characterized by FTIR, 1H-NMR, 13C-NMR, and mass spectroscopy, and evaluated for their antimicrobial, antiinflammatory, and antioxidant activities along with in silico studies. The substituted derivatives were synthesized by the reaction of acetonitrile, chlorosulphonic acid, and substituted benzaldehyde with the hydrazones. The antimicrobial evaluation showed that compound 3i had more antimicrobial potential than the other tested molecules. Compound 3j had more antioxidant potential than the other synthesized compounds. Two compounds, 3f and 3h, had better antiinflammatory activity. The binding affinities of synthesized derivatives into the active sites of receptor proteins were characterized by utilizing the advanced docking program AutoDock Vina. In silico ADMET studies were performed using Molinspiration, pre-ADMET, and OSIRIS property explorer for the prediction of pharmacokinetic behavior of synthesized compounds.