BMC Chemistry最新文献

The extensive use of antibiotics and their persistence in the environment make them emerging pollutants of global concern, posing serious risks to ecosystems and public health. Among them, the broad-spectrum fluoroquinolone antibiotic levofloxacin (LEV) is widely prescribed for bacterial infections and has frequently been detected in freshwater systems and environmental matrices. Its presence is linked to the development of antibiotic resistance and ecological toxicity, underscoring the urgent need for efficient removal strategies. In this study, levofloxacin-imprinted polymers (LEV-MIPs) were developed using a precipitation polymerisation method. A set of nine LEV-MIPs was synthesised using three solvent combinations: ethanol: acetonitrile, ethanol: dimethyl sulfoxide, and ethanol: carbon tetrachloride. Methacrylic acid (MAA) served as the functional monomer (1–3 mmol), ethylene glycol dimethacrylate (EGDMA) as the cross-linker (16 mmol), and azobisisobutyronitrile (AIBN) as the initiator (0.1 mmol). Among them, two formulations (LEV3-MIP and LEV6-MIP) demonstrated superior removal efficiency. Structural and thermal characterisation by FTIR, SEM/EDX, and TGA confirmed successful polymer synthesis, with surface analysis revealing spherical, monodispersed particles of ~ 1.5 μm. Batch adsorption assays showed removal efficiencies of 97.85% (LEV3-MIP) and 99.15% (LEV6-MIP) under optimised conditions (15 ppm initial concentration, 0.3 mg dosage, pH 7, and 90 min and 60 min contact time, respectively). Both polymers exhibited high imprinting factors (3.081 and 3.359) and excellent reusability, with minimal efficiency loss of only 2.7% and 2.09% after ten adsorption–desorption cycles. These results highlight the strong potential of LEV-MIPs as cost-effective, selective, and reusable materials for mitigating antibiotic pollution.

In this study, a range of photocatalysts, including zinc and cerium oxides, were developed using the precipitation technique, while impregnation was used to produce multiwalled CNTs with zinc oxide, multiwalled CNTs with zinc oxide/cerium oxides, and zeolite-based multiwalled CNTs with zinc oxide/cerium oxides. Advanced instruments, such as XRD, UV-Vis, and photoluminescence (PL) devices, were used to analyze the crystal structure, bandgap, and optical properties of each photocatalyst. Methylene blue, an organic contaminant, and sewage from Ethiopia’s Bahir Dar cloth industry were used to assess the photocatalytic efficacy of both assisted and unassisted nanocomposites. Under visible light irradiation, the TZ (zeolite with MWCNTs/ZnO/CeO₂) demonstrated a higher degradation performance of MB dye than the T3 nanocomposite, attaining 93.71% and 83.21%, respectively. This implies that by increasing the adsorption capacity, zeolite greatly improves the composite’s performance. The stability of the TZ in photocatalytic degradation was assessed, showing a 20.8% reduction after four consecutive runs, confirming the nanocomposite’s good stability. Furthermore, the mentioned photocatalyst (TZ) demonstrated greater performance in the degradation of MB with approximately 94.12% compared to the sewage sample efficiency of 76.75%.

Ionic liquids (ILs) have gained significant attention among material scientists for their versatile properties. Amino acid-based ionic liquids (AAILs) have the potential to be tailored for desired physicochemical properties due to their structural adaptability and unique attributes. Twenty-four distinct ILs were synthesized, containing multifunctional cations viz. 1-octyl pyridinium, 1-octyl-3-methylimidazolium, 1,3-dioctylimidazolium, Di-octyldi-butylammonium, Tetraoctylphosphonium, N, N, N', N'-Tetrakis-(2-hydroxyethyl)dioctyldiammonium, 1H-1,2,3-triazole, and 1-octyl-1,8-diazabicyclo(5.4.0)undec-7-enium, each with varied chain lengths. Whereas, bromide, glycinate, and leucinate were incorporated as counter-anionic species. These distinct ILs were characterized by FT-IR, ¹H, and ¹³C-NMR spectroscopies and were systematically evaluated for anti-bacterial efficacy by agar well diffusion method against six potent bacterial strains. Both gram-positive as well as gram-negative types, namely Shigella dysenteria, Shigella boyydii, Staphylococcus aureus, Carbapenem-resistant Enterobacter baumannii, Escherichia coli, and Klebsiella pneumonia were tested. Remarkably strong antibacterial performance was observed across most of the synthesized ILs, particularly notable against gram-negative strains, signifying their potential as antibacterial agents. The good antibacterial performance of ILs was also validated by molecular docking, and a good agreement was found between computational and experimental studies. These findings open new avenues for the development of effective antibacterial agents based on ILs in infection control for individuals with disabilities.

A series of simple and cost-effective benzylidene-amine appended probes (E)-4-((4-(allyloxy) benzylidene)amino)-N-phenyl aniline (L-1), (E)-N-phenyl-4-((2,3,4-trimethoxybenzylidene) amino)aniline (L-2), and (E)-4-((2-nitrobenzylidene)amino)-N-phenyl aniline (L-3) have been developed for the rapid detection of picric acid (PA) and explored for the same. Notably, L-3 showed no changes in its UV spectrum or colour upon interaction with PA. In contrast, when PA was added to L-1 and L-2, there were significant changes in absorption, resulting in distinct colour changes. Mole fraction analysis indicated a 1:1 ratio between the probes and PA. The detection limits for PA were impressively low, measuring 4.37 × 10^− 7 M for L-1 and 4.56 × 10^− 6 M for L-2. This demonstrates the effectiveness of these probes in detecting PA, even at very low concentrations. Importantly, this work marks the first application of benzylidene-amine probes for the detection of PA. The sensing studies were supported by theoretical analyses and calculations, which confirmed the selective detection of PA using matchstick head powder (MSPS) and a test kit based on paper strips. Additionally, smartphone-assisted detection using an RGB tool was successfully demonstrated.

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The formation of C–C and C–N bonds is an effective means to construct functional complex molecules. Herein, the TsOH-promoted dehydroxylation coupling of diarylmethanols with 1,3-dicarbonyls and sulfonamides to afford a variety of N-alkylated1,3-dicarbonyls and sulfonamides was established with only H₂O as the byproduct. Differential 1,3-dicarbonyls and sulfonamides, including pharmaceutical molecules (sulfinpyrazone, phenylbutazone, mofebutazone, celecoxib, topiramate, valdecoxib) were compatible with this system to couple with alcohols in moderate to excellent yields. This method shows the merits of wide substrate scope and mild conditions.

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A rapid, accurate, sensitive, and eco-friendly micellar liquid chromatography method has been successfully developed and validated for the simultaneous determination of clindamycin and adapalene in their bulk forms and combined dosage gel formulations. The separation was performed on a BDS HYPERSIL C18 column (150 × 4.6 mm, 5 μm), employing a micellar mobile phase made up of 0.07 M sodium dodecyl sulfate, 0.3% triethylamine, 0.02 M orthophosphoric acid (pH adjusted to 3.0), and 14% isopropanol (v/v). Detection was carried out using UV at 210 nm. The method exhibited linearity in the ranges of 100–500 µg/mL for clindamycin phosphate and 10–50 µg/mL for adapalene, with detection limits of 13.4 µg/mL and 1.4 µg/mL, respectively. The developed method was effectively applied to the analysis of a laboratory-prepared co-formulated gel, yielding high recovery rates. The greenness of the method was further confirmed through assessment with the Green Analytical Procedure Index (GAPI). The method was also validated as a stability-indicating assay for clindamycin phosphate and adapalene under various stress conditions, demonstrating its robustness and applicability for routine quality control.

Luminescent sources based on crystalline materials doped with transition metal or rare-earth cations are known as persistent phosphors, and they can continue to emit light even after the excitation source has disappeared. The present study aims to prepare strontium aluminate with varying weight percentages of Eu²⁺, RE³⁺ (RE = Dy³⁺, Nd³⁺, or B³⁺) oxides by the solid-state preparation followed by firing under active carbon at 1250 °C.The produced phosphors were examined using FTIR spectroscopy, mechano-luminescent measurement, scanning electron microscopy (SEM), and X-ray diffraction (XRD). A bulk density and apparent porosity measurement was also used to assess the impact of the firing temperature at 1250 °C. Photoluminescence characteristics were examined concerning the kind of trivalent oxides doped in strontium aluminate. The results showed that for samples containing 0.15 weight% of Eu₂O₃ and 0.15 weight% of RE₂O₃, SrAl₂O₄ formed with Eu^+ 2, RE³⁺ as a single phase. However, RESr₂AlO₅ was formed together with a minor amount of SrAl₂O₄ when the Eu₂O₃ contents decreased at the expense of the RE₂O₃ contents. Additionally, it was observed that the Eu³⁺ was converted into Eu²⁺ for every sample. Every sample had porous behavior, and the bulk density was increased by the inclusion of RESr₂AlO₅ in addition to SrAl₂O₄. Transitions from the 4f⁶ and 5d¹ configurations of the emission center (Eu²⁺ ions) to the 4f⁷ configuration result in a broad band at peaks of 517 nm in the emission spectra of all the samples. Samples containing RESr₂AlO₅ exhibit high phosphor color characteristics, forming red-orange phosphors encircled by green phosphor rings. Compared to samples containing Nd₂O₃ and B₂O₃, those containing Dy₂O₃ phosphor have the highest decay time values.

α-Tocopherol (α-TQ) is a potent antioxidant with diverse applications in the food and pharmaceutical industries. It is susceptible to oxidation by various reactive oxygen species (ROS). This study first identifies the oxidation product of α-tocopherol produced by either H₂O₂ or HOCl, which could be formed in foods and biological systems. Second, the kinetic and mechanistic aspects of these oxidation reactions are characterized. Finally, the anticancer activity of α-TQ and its oxidation products was revealed. The direct oxidation product is α-tocopheryl quinone (α-TQQ), which dimerizes through an ether linkage and undergoes addition reactions. LC-MS/MS identified new products, primarily including positional and diastereoisomers of α-TQQ dimers resulting from H₂O₂ and HOCl addition. A kinetic study demonstrated that the oxidation reaction is first-order for both α-TQ and H₂O₂ or HOCl. The mechanism is proposed based on the identified products and kinetic behavior. The postulated mechanism also aligns with the reaction’s UV-Vis spectra, including the formation of the hemiketal (242 nm) and α-TQQ (261 nm) intermediates, as well as the addition products of the α-TQQ dimer (265 nm). α-TQQ dimer products of H₂O₂ oxidation reaction exhibited 1.7-fold (IC50 264.72 µM) and 2.0-fold (IC50 253.72 µM) higher cytotoxicity than that of α-TQ (IC50 448.45 and 496.53 µM) against breast (MCF-7) and prostate (PC-3) cancer cells, respectively. These results indicate that natural α-TQ and its oxidation products, when administered at a suitable dose, can express protection against various types of cancer.

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This study reports the development of a novel, low-cost, and highly sensitive sensor for the rapid and efficient electrochemical detection of trace amounts of the antibiotic Linezolid (LNZO) in both synthetic solutions and real samples. The proposed sensor is based on a carbon paste electrode (CPE) modified with calcium oxide nanoparticles (CaO-NPs) and further enhanced through electropolymerization of D-alanine (PoDA). Eggshell waste was recycled as a low-cost and eco-friendly source of calcium oxide nanoparticles (CaO-NPs). The synergistic effect of CaO-NPs and the electropolymerized D-alanine (PoDA) film enhanced the electrocatalytic activity of the carbon paste electrode (CPE) toward Linezolid (LNZO). The fabricated sensor was characterized using FTIR, XRD, and SEM techniques. It exhibited excellent electro-oxidation performance toward LNZO, demonstrating high sensitivity, a very low detection limit, good selectivity, and acceptable reproducibility. Differential pulse voltammetry provided a wide linear range (0.005–0.1 µM) with a detection limit of 1.27 nM. Importantly, the sensor successfully detected LNZO in real samples, achieving recovery rates between 95.70% and 100.20%, confirming its effectiveness for practical applications the developed sensor confirmed the ability to identify LNZO in real samples, yielding acceptable recovery percentages within the range of 95.70% to 100.20%, proving the method’s effectiveness in practical applications.

Clozapine (CLZ); an atypical antipsychotic drug, is well known to have a significant role in managing schizophrenic patients with substance use disorder (SUD). Unfortunately, many patients are deprived of CLZ benefits due to its limited prescription. This is based upon concerns regarding the critical side effects of CLZ in case of overdosing especially, with the lack of accessible therapeutic drug monitoring (TDM) tools. In this contribution, a simple, accurate and sensitive electrochemical method is proposed for CLZ assay in human saliva. Unlike previously reported methods for TDM of CLZ that depends on invasive matrices as plasma and urine, this method employs electrochemical approaches in exploring human saliva as a patient-friendly alternative for assessing CLZ. The proposed method employs differential pulse voltammetry (DPV) with a sensitive and selective Ag-doped ZnO nanoparticles based carbon paste electrode (CPE). The adopted electrochemical sensor has not been previously reported for CLZ determination, despite it offers enhanced sensitivity together with simple synthesis. The synthesized nanoparticles were characterized through Fourier-transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM) and energy dispersive X-ray spectroscopy (EDX). The developed sensor was optimized and validated as per FDA guidelines of bioanalytical methods. The linear range in saliva was 0.31–3.67 µmol/L and the lower limit of quantitation (LLOQ) was 0.31 µmol/L. The high reliability and applicability of the suggested method has strong potential to be integrated in a point-of-care testing (POCT) device to introduce more accessible TDM that enables smooth TDM of CLZ. Therefore, it opens pathways for broader and safe use of CLZ.

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