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Cellulose filter paper (CFP) was modified with poly(acrylic acid) (PAA) and/or poly(ethylene glycol)methacrylate (PEGMA), followed by Cu immobilization for 4-nitrophenol (4NP) reduction. Among these samples, Cu-immobilized CFP modified with PEGMA polymer (CFP@PEGMA-Cu) exhibited the highest Cu incorporation of 2.21%. Those having the copolymer (CFP@PAA-co-PEGMA-Cu) demonstrated the highest efficiency, completing 4NP reduction in 3 min with an impressive 99.45% conversion, a high-rate constant (k) of 27.5 × 10−3 s−1, and turnover frequency (TOF) of 18.36 h−1. Notably, the catalysts containing PAA maintained good reusability, preserving 97% conversion upon 9 cycles. These results suggest their promising applications in sustainable catalysis, offering the catalytic potential with simple preparation and low cost required. [ABSTRACT FROM AUTHOR]

Magnetite nanoparticles coated with quaternized poly(diethylamino)ethyl methacrylate (PDEAEMA) (PQDEA@MNP) and functionalized with bisphenol A (BPA)-specific peptide aptamer (CKSLENSYC) were synthesized and used as nano-adsorbents for selective adsorption with BPA. The polymer coated on the particles provided their good stability and dispersibility in water, and the aptamer provided selective adsorption with BPA targets. Fourier transformed infrared spectrophotometry (FTIR), thermogravimetric analysis (TGA) and vibrating sample magnetometry (VSM) techniques confirmed the presence of the polymer on the particle surface. From transmission electron microscopy (TEM) study, the particle size was ca.6 - 10 nm in diameter with some nanoclustering (30 - 60 nm in diameter of the nanoclusters). The selective adsorption of BPA on the particles was predominant over the non-specific adsorption when performed in PBS buffer (pH 10) in the presence of NaCl and tween-20. The nano-adsorbents had a good linearity range for the detection of BPA between 0.04 and 0.20 ppm with limit of detection (LOD) of 0.0145 ppm. They retained good BPA adsorption efficiency even when other interfering molecules were present. This simple measurement with the use of these nano-adsorbents without molecular labelling might be promising solid supports for use in various applications with good tolerance towards interfering molecules. [ABSTRACT FROM AUTHOR]

Abstract Colorimetric sensors from N -butyl-3,6-disubstituted carbazole derivatives containing nitroazobenzene (1) and nitrobenzene (2) were designed, synthesized and compared for their anion sensing ability. Computational simulations were undertaken to determine the optimum geometry of 1. Anion sensing studies revealed that selectivity in anion detection depended on the polarity of solvent, acidity of binding unit and basicity of the anion. The ability to sense via naked eye observations using the strong basic anions (F− and CN−) for both sensors arises from a deprotonation process at the binding sites attributed to the intramolecular charge transfer transition at the sensory unit. The discrimination of F− from CN− has been achieved by the optimization of solvent polarity. Sensor 1 offers a promising property over sensor 2 with a lower detection limit, a few of anion interference and higher stability. Graphical abstract Unlabelled Image Highlights • Development of F− and CN− selective chemosensors from carbazole derivatives. • Naked eye color change of chemosensors arising from the deprotonation at the binding sites. • The discrimination of F− from other anions achieving from the optimization of solvent polarity. [ABSTRACT FROM AUTHOR]