Turkish Journal of Chemistry最新文献

Organomontmorillonite (organo-MMT) nanocomposites are widely used in environmental, food, and pharmaceutical applications. However, their weak adsorption and ionic exchange forces during synthesis can make them unstable and unreliable. In this study, we present a novel synthesis of stable mesoporous iminocyclohexanone-Ca-MMT nanocomposites through a green, rapid, one-pot reaction. The synthesis reaction between Ca-MMT clay suspended in water and a dioxane solution of 1,3-cyclohexanedione and 4-aminophenol at 2 temperatures (60 °C and 110 °C) completed in a short reaction time. The resulting nanocomposites were characterized using X-ray diffraction, Fourier transform infrared spectroscopy, nuclear magnetic resonance UV-visible spectroscopy, and advanced software tools. Surface area measurements were performed via multipoint Brunauer-Emmett-Teller analysis. The stability of these nanocomposites come from the formation of coordination bonds between the iminocyclohexanone moiety and Al, Mg, and Si minerals in the octahedral and tetrahedral layers of Ca-MMT. This innovative approach addresses the temporal instability issues of conventional organoclay nanocomposites, offering promising potential for broader industrial and environmental applications.

An ultrasensitive impedimetric immunosensor was fabricated using a poly(glycidyl methacrylate) (PGMA) polymer-covered indium tin oxide (ITO) platform for the quantification of kallikrein 4 (KLK4), an important prostate cancer biomarker. PGMA had suitable biocompatibility and nontoxicity for loading of antiKLK4 antibodies on the ITO substrate surface. Anti-KLK4 biomolecules were directly attached to the PGMA-covered electrode surface via epoxy groups of the PGMA polymer. The preparation method for the PGMA matrix-modified electrode was simple and inexpensive. The proposed biosensor immobilization layers coated on the ITO electrode were characterized with electrochemical techniques. The experimental parameters that affect biosensor response were optimized, and the suggested sensor showed a linear response from 0.04 pg/mL to 8 pg/mL with a low detection limit (LOD) of 12.21 fg/mL. Moreover, it had acceptable stability, reproducibility, and repeatability. Additionally, the disposable biosensor offered excellent reliability and accuracy in KLK4 analysis, suggesting that it could be used as an alternative technique in clinical diagnosis.

A synthesized zwitterionic monohydroxyl monomer (ZHM) was used as an additive to incorporate zwitterionic sulfobetaine groups into the polyamide (PA) active layers of thin-film composite membranes. Incorporation of ZHM into the PA active layers was achieved through interfacial polymerization, involving the introduction of ZHM and m-phenylenediamine (MPD) into the aqueous phase, and the addition of trimesoyl chloride (TMC) to the hexane phase. The surfaces of the resulting reverse osmosis (RO) membranes were subjected to characterization through water contact angle (WCA) and field emission scanning electron microscopy (FESEM) analyses. The successful incorporation of ZHM into the active PA layers was confirmed by X-ray photoelectron spectroscopy (XPS) and Fourier transform infrared spectroscopy (FTIR) analysis. To assess the flux and salt rejection performance of the fabricated membranes, aqueous solutions containing 2000 ppm NaCl or MgSO₄ were filtered in a dead-end filtration system under a pressure of 15 bar. Compared to the control membrane (ZHM-0), the ZHM-modified membranes had significantly enhanced flux without compromising salt retention. In the NaCl solution filtration, the modified membrane (ZHM-1) increased in flux from 6.8 to 9.1 L/m²h while having similar salt rejection (approximately 91%) in comparison to the control membrane (ZHM-0). In the MgSO₄ solution filtration, the modified membranes increased in flux from 6.7 to 9.5 L/m²h, while maintaining a consistent salt rejection rate of 100%, mirroring that of the control membrane.

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.

This study's main goal was to produce a user-friendly dispersive micro solid phase extraction (dmSPE) technique with a MIL-53(Al)@BaTiO₃ nanocomposite for the extraction and preconcentration of cadmium (Cd) in various seafood matrices, followed by using high-resolution continuum source flame atomic absorption spectrometry (HR-CS-FAAS). The MIL-53(Al)@BaTiO₃ nanocomposite was synthesized and characterized using a range of techniques, including Fourier-transform infrared spectroscopy, field emission scanning electron microscopy, scanning transmission electron microscopy, X-ray diffraction, and Brunauer-Emmett-Teller analysis. The dmSPE technique involved the dispersion of the MIL-53(Al)@BaTiO₃ material in the sample solution, followed by its separation from the sample matrix. The optimized method exhibited a linear range of 3.6-250 μg L^-1, a limit of detection (LOD) of 1.2 μg L^-1, and a preconcentration factor of 80. Two different certified reference materials were used to ensure the validation of developed method. The method was applied to different seafood samples.

The electronic and optoelectronic properties of 8 C^N^N- and C^C^C-chelated Ir(III) complexes were investigated using density functional theory at the Becke-style 3-parameter Lee-Yang-Par and triple zeta plus polarization level. Based on reorganization energy calculations, complex 7 was identified as a promising ambipolar material, while complexes 1 and 2 had efficient hole transport properties. Complex 8 had low ionization potential and is therefore a strong candidate for hole transport applications. Complex 4 had high electron affinity and therefore has potential as an effective electron acceptor material. Photophysical analysis showed that all complexes had phosphorescent properties, with complexes 5 and 6 showing particularly small singlet-triplet energy gaps, making them ideal for high-performance phosphorescent organic light-emitting diodes (PhOLEDs). The intersystem crossing and reverse intersystem crossing rates indicated that these complexes are more likely to have phosphorescence rather than thermally activated delayed fluorescence. These findings provide valuable insights for the design of efficient OLED materials.

Polyaniline (PANi) was hybridized with a bagasse (BG) substrate to treat Dichlorodiphenyltrichloroethane (DDT), dichlorodiphenyldichloroethylene (DDE), and dichlorodiphenyldichloroethane compounds, which are persistent organic pollutants (POPs) causing environmental contamination. The PANi/bagasse (PA/BG) composite was synthesized using ammonium persulfate and sulfuric acid, achieving efficiencies ranging from 82.63% to 86.92% with different ratios of PANi monomer to BG. Infrared spectroscopy (IR) and scanning electron microscopy (SEM) were used to characterize the synthesized materials. The adsorption capacities of DDT, DDD, and DDE compounds were investigated under various conditions, including adsorbent type, adsorption time, adsorbent dosage, and adsorbate concentration. Both Langmuir and Freundlich isotherm models were applied to evaluate the adsorption process, and the results indicated that both models were suitable for describing the adsorption of DDT, DDD, and DDE by the PANi/bagasse composite material.

This study presents an original, effective, and environmentally friendly method for synthesizing pure molybdenum carbide (Mo₂C) from ammonium molybdate tetrahydrate (AMT) without generating carbon dioxide, a greenhouse gas. The process involves the sequential transformation of AMT to Mo₂C, which follows the reaction pathway of (NH₄)₆Mo₇O₂₄→MoO₃→MoO₂→Mo→Mo₂C. This transformation is achieved by strategically altering the gas atmosphere, switching from Ar to H₂ at 800 K and then from H₂ to CH₄ at 1000 K. Thermal analysis, X-ray diffraction (XRD), and scanning electron microscopy (SEM) techniques were used to characterize AMT and the products. Mass measurements were used to follow the conversion of AMT to intermediate products and to the final product (Mo₂C). It was found that 57.67% of AMT was converted to Mo₂C, in agreement with the theoretical value (57.74%). Differential scanning calorimetry/thermogravimetry curves revealed four steps at 401 K, 495 K, 507 K, and 595 K during AMT decomposition to MoO₃. XRD patterns revealed the formation of phase-pure Mo₂C, with characteristic diffraction peaks 2θ = 34.176°, 2θ = 37.712°, and 2θ = 39.197° assigned to the (100), (002), and (101) crystal planes, respectively. SEM images showed that fine Mo₂C particles with a thickness of 0.1 μm was obtained from very coarse AMT particles (>50 μm). In order to determine the solid and gaseous phases likely to form during the reaction, thermodynamic analysis using Gibbs' free energy minimization method was also carried out prior to synthesis. The reduction reactions and the resulting morphologies of the synthesized materials were discussed in terms of thermodynamic results and density changes associated with the conversions. This study demonstrates a novel reaction pathway that sequentially converts the molybdenum species from Ammonium Molybdate Tetrahydrate (AMT) to the final Mo₂C phase without the release of CO₂.

A label-less impedimetric biosensor modified with poly(thiophene)-graft-poly(glycidyl methacrylate) polymer (PThi-g-PGM) was manufactured for p53 protein quantification in human serum samples. In this study, PThi-g-PGM polymer was synthesized, and this polymer matrix was coated using the spin-coating technique on the single-use indium tin oxide (ITO) substrate for anti-p53 antibody immobilization. The anti-p53 antibodies with high affinity for p53 proteins were covalently attached onto the PThi-g-PGM-coated electrode surface. In addition, the affinity of anti-p53 for the p53 protein was monitored at a constant frequency. Under optimized conditions, the impedimetric changes were linearly related to the p53 concentrations, ranging from 0.05 to 15 pg/mL with a low detection limit of 15.9 fg/mL. This biosensor had desirable storage stability, acceptable repeatability, and high reproducibility. Moreover, this impedimetric biosensor could be regenerated through an acidic treatment procedure. Additionally, the suggested biosensor successfully detected the p53 antigen in human serum samples, and good recycling rates (98.41%-109.32%) were found. In summary, the proposed immunosensor may be a powerful tool for the analysis of the p53 protein for early detection of cancer biomarkers.

In this research, a fast and simple spectrophotometric method is presented for mitoxantrone determination in various aqueous samples. It utilizes preconcentration by salt saturated pipette-tip micro solid phase extraction with a selective molecularly imprinted polymer adsorbent packed in a micropipette tip. Prior to sample loading, they were saturated with a mixture of NaCl, Mg (NO₃)₂.6H₂O and KNO₃ salts, enhancing extraction efficiency by 27.5% compared to salt-free conditions. Key microextraction parameters (amount of molecularly imprinted polymer, sample pH, eluent type/volume, and adsorption/desorption cycles) were optimized using response surface methodology and one-variable-at-a-time methods. The method achieves a low detection limit (0.2 μg L^-1) and a wide linear range (1-1000 μg L^-1). An enrichment factor of 49 is obtained with excellent accuracy (relative standard deviation <4.4%). The method was validated by comparing it to a standard high performance liquid chromatography protocol, as well as spiking real samples in three concentration levels. The method successfully detected low levels of mitoxantrone in various water samples.