Chemical Papers最新文献

A simple fabrication route for an all-solid-state carbon paste Cu(II)-selective potentiometric sensor on the basis of composite sensing layer consisting of PbS microparticles, graphite (G), multi-walled carbon nanotube, and paraffin oil has been propounded. Optimization studies for sensing composite layer signified that the composite contained 10 mg PbS, 10 mg MWCNT, 60 mg G, and 20 mg PO exposed the most promising potentiometric performance properties. The sensor displayed a stable and selective linear response to Cu(II) ions in the concentration range of 1.0 × 10⁻⁶–1.0 × 10⁻² M (R² = 0.9992) with an average potential change of 30.2 mV/decade. Detection limit, response time, and life-span of the sensor were determined as 5.0 × 10⁻⁷ M, 15 s, and 3 weeks, respectively. The fabricated sensor was successfully used in practical applications, serving as an indicator electrode to determine the end-point of Cu(II) titrations and to measure Cu(II) content in Cu(II)-spiked tap water samples.

Graphical abstract

Bioimaging is a well-known process for visualizing biological substances or biological pathways in the human body at a molecular level without any intrusion. It has been used in various domains biological of chemistry, drug discovery, and disease detection, due to its potential application attributes of high resolution, high sensitivity, high selectivity, and low cost. In recent years, the transition metal-based luminescent probes or photosensitizers have a distinctive feature in optical bioimaging and photodynamic therapy, in in vivo and in vitro, as compared to other types of probes and have a strong influence on discovering biological analytes. Photodynamic therapy, a non-systemic treatment, has attracted significant attention for its ability to localize the disease. This depends on the nature of the photosensitizers, light, and reactive oxygen species (ROS), produced through electron transport or energy transfer pathways. In PDT, a photosensitizer (PS) gets activated on exposure to light of a specific wavelength and provides energy to molecular oxygen on the tissue surfaces. This generates reactive oxygen species such as superoxide, singlet oxygen, and hydroxyl radicals causing damage to cellular membranes, lipids, proteins, and DNA. Further, it also results in cell death via apoptosis and necrosis on targeted cancer cells. The current review provides a literature overview on bioimaging and PDT applications of reported ruthenium and platinum complexes acting as luminescent probes. The extensively studied ligands, in this context, are bipyridine, phenanthroline, porphyrin, BODIPY, and ferrocene. These complexes have been studied for their potential anticancer activity against different cancer cells in both light and dark conditions. In addition, these probes also possess excellent photophysical characteristics of intense emission, with significant Stokes shifts, extended lifetimes, controllable toxicity, and excellent photostability.

Graphical abstract

Catalytic conversion of water pollutants into environmentally benign products has emerged as a highly promising technique in the realm of environmental remediation. Among metal and metal oxide nanoparticles, copper/copper oxide nanoparticles serve as an ideal catalyst to reduce hazardous aquatic pollutants in order to protect the environment. In the present study, a simple chemical oxidation method was used for the synthesis of Cu(OH)₂ nanowire, which was then annealed in argon atmosphere at different temperatures. On annealing, Cu(OH)₂ gets transformed into oxide forms, CuO and/or Cu₂O. The significance of the synthesized nanomaterial for the catalytic conversion of organic pollutants like para-nitrophenol (p-NP) and para-nitroaniline (p-NA), to para-aminophenol (p-AP) and para-phenylenediamine (p-PDA), respectively, in the presence of NaBH₄ was studied and their catalytic activities were compared, and the rate constants were found to be 0.016 s⁻¹ and 0.021 s⁻¹ for p-NP and p-NA respectively. Due to the increased surface area, which improves charge carrier separation and adsorption, the CuO/Cu₂O hybrid nanowires established excellent catalytic behavior for the conversion of these harmful pollutants into useful products within a few minutes. In addition to this, the heterojunction of CuO/Cu₂O hybrid nanowires formed are effectively catalyze the “clock reaction,” which is a periodic reversible switching of reactions between colorless leucomethylene blue and blue colored methylene blue. This property of the developed nanocomposite has been used in the visual colorimetric detection of Zn²⁺ions, with high limit of detection of 53 nM and high sensitivity. Morphology and surface analysis were obtained by X ray diffraction, Raman, and Scanning Electron Microscopic analysis and the reaction kinetics were studied by UV–visible spectroscopy. The recyclability of the synthesized catalyst was investigated over five cycles, and it maintained consistent performance, achieving 95% conversion efficiency for p-NP and 93% for p-NA after the five cycles.

Graphical abstract

One of the major limitations of anti-cancer drugs is their poor selectivity and high toxicity. The present study aims to overcome these difficulties by developing targeted drug delivery systems. Drug delivery systems were synthesized based on magnetite nanoparticles with grafted poly(2-vinylpyridine) from their pre-modified surface with 3-(trimethoxysilyl)propyl methacrylate. The physical and chemical properties of synthesized samples were examined by Fourier-transform infrared spectroscopy, X-ray diffraction, vibrating-sample magnetometry, Energy-dispersive X-Ray analysis and thermogravimetric analysis. The size of nanoparticles was estimated by DLS, final Fe₃O₄-TMSPM-P2VP-5FU nanoparticles have an average size of 120 nm (PDI is 0.286). Release of 5-FU was examined at different pH (4.5 and 7.58) and constant temperature of 36.6 °C using UV–Vis spectroscopy.

The new Mn (II) complex of the “salamo” salen ligand of unsymmetrical oxime was synthesized and immobilized on MCM-41 by the multi-grafting method. The immobilized unsymmetrical salamo complex of manganese (MCM-41-Mn salamo) was used as a catalyst in the epoxidation of the alkenes with H₂O₂. The effect of various reaction parameters which may affect the conversion such as reaction time, temperature, amount of catalyst, oxidant and imidazole was investigated. The prepared Mn catalyst exhibited excellent reusability and could be reused at least five times without significant leaching or loss of activity.

Ceramic membranes based on SiC have a number of advantages, namely high surface hydrophilicity, good water permeability and negative surface charge, which leads to better performance during their operation, but they require high sintering temperatures due to covalent bonds. The use of sintering agents can significantly reduce the final sintering temperature. The aim of this work was to synthesise ceramic membranes based on silicon carbide and to study the effect of liquid glass on their mechanical, electrical and antibacterial properties. The physicochemical properties of SiC ceramic membranes were investigated by diffraction analysis and scanning electron microscopy. It was found that, regardless of the type of carbonate, only two phases are identified: the main phase of the initial mixture, silicon carbide and the phase added to the mixture, corundum. The obtained SiC ceramic membranes are macroporous, as indicated by the transport properties (9.03–18.66 cm³/(min-cm²)) and the results of electron microscopy (13–20 μm). SiC ceramic membranes obtained are characterised by high strength (16.3–46.8 MPa). Studies of antibacterial properties have shown that SiC-based ceramic membranes do not exhibit antibacterial properties, but modification of ceramic membranes with titanium oxide inhibits the growth of gram-negative bacteria. The results of this study are useful for enriching the knowledge about the production of silicon carbide membranes and are aimed at further research and development of selective membranes (micro- and ultrafiltration) based on them.

The development of rapid and sensitive malachite green (MG) detection methods is particularly important for food safety supervision and ecological protection. Using fulvic acid (FA) as a stabilizer and NaBH₄ as a reducing agent, ellipsoidal gold nanoparticles (AuNPs) with the average particle size of 5–20 nm were successfully prepared. Based on the interaction between fulvic acid protected gold nanoparticles (FA-AuNPs) and MG, the color change of FA-AuNPs from ruby red to blue was observed, the corresponding absorbance ratio change of gold nanoparticles at 611 nm and 529 nm (A611/A529) was also studied. Through the optimization of experimental conditions, the linear relationship between A611/A529 with the concentration of MG was established. The detection limit and linear range of this method were 0.02 μM and 0.04–2 μM, respectively. This method was successfully applied to detect malachite green in three different water samples with the recovery of 97.4–110.8%.

Graphical abstract

The use of renewable energy is becoming common due to increased power demand, fluctuating oil prices, and environmental concerns. Air breathing direct methanol fuel cells (ABDMFCs) offer a promising alternative for low-power and portable applications due to their quick recharging, high efficiency, long lifespan, low fuel cost, reduced pollution, and quiet operation. This paper reports on three stages of experimental research on ABDMFCs. In the first stage, we examined the influence of cathode current collector design on the performance of conventional ABDMFC with a single serpentine (1-S) graphite flow field design at anode, and changed methanol concentrations and the methanol flow rates, achieving a power density of 6.8 mW/cm². The second stage involved adding NaOH (liquid flowing electrolyte—FE) to the methanol fuel, which increased the power density to 7.5 mW/cm² and reduced methanol crossover. In the third stage, introducing a liquid electrolyte (LE) layer between two membrane electrode assemblies (MEAs) further improved the power density to 8.32 mW/cm², reducing methanol crossover. Compared to conventional ABDMFCs, the addition of NaOH and the LE improved power density by 10.3% and 22.35%, respectively.

Diabetes mellitus, often known as hyperglycemia, is a serious worldwide disease now. In clinical pharmacology, the dipeptidyl peptidase IV (DPP-4) enzyme is important for glucose homeostasis. The clinical DPP-4 blockers are essential oral antidiabetic medications used as alternate treatment following metformin inability as insulinotropic drugs with no inherent risk of hypoglycemia. The objective of this study is to create novel and potent DPP-4 inhibitors by molecular hybridization of eight clinically licensed DPP-4 inhibitors. Molecular hybridization process led to the creation of five novel hybridized DPP-4 inhibitors, which preliminary computational studies suggest may exhibit improved selectivity compared to authorized DPP-4 inhibitors. The pharmacokinetic features of the hybridized inhibitors, including their solubility and potential to pass through biological tissues, were evaluated using Lipinski’s rule of five and other druglikeness filters, indicating favorable properties for reaching the DPP-4 active site. Furthermore, the possible toxicity of suggested inhibitors was investigated using basic toxicity filters and PASS, indicating no immediate red flags regarding their potential toxicity and metabolism. In addition, a mechanism for synthesizing the proposed compounds has been developed via machine learning and artificial intelligence algorithms. At the biomolecular level, using the Gromacs package, molecular dynamics simulations (100 ns) were performed for all the studied systems. Following analyzing the molecular dynamics trajectories and evaluating the dynamic shifts of DPP-4 after its molecular interactions with the designed compounds via dynamic cross-correlation matrix, free energy landscape and MM-PBSA calculations, all data show that the proposed DPP-4 inhibitors create extremely stable complexes when compared to the clinical DPP-4 inhibitor (alogliptin). Finally, the findings of this study might greatly contribute to the development of novel and potent DPP-4 inhibitors and assist in the search for new medications for diabetes type 2.

Graphical abstract

Utilizing stacked monolayers in the form of van der Waals heterostructures is an effective approach for manipulating band gaps and exciton dynamics in potential nano-electronic devices. Our study employed first principle calculations to investigate the structural, electronic, thermoelectric properties of MSSe-PtSSe (M = Mo, W) van der Waals heterostructures. We used different stacking order and find the most stable stacking from their relaxation energies for further confirmation we calculated their binding energies to confirm the stability of the most favorable stacking. These materials are identified as indirect band gap type-I semiconducting heterostructure having type-I band alignment. By applying moderate in-plane tensile and compressional strain, the indirect band nature is retained while switching of band alignment is observed with the application of strain. The thermoelectric properties of these heterostructures were explored using the semi-classical Boltzmann transport theory. The significant Seebeck coefficient observed in these heterostructures provides evidence that these materials are well-suited for thermoelectric devices in unstrained condition. Strain induced thermoelectric response shows enhanced value of power factor with compressional strain in WSSe-PtSSe heterostructure.