Removal of Pb(II) from Aqueous Solutions Using Magnetic Mesoporous Silica Nanocomposites: Modeling and Optimization Based on Response Surface Methodology

In the adsorption process of heavy metals, a major challenge is to design and develop adsorbent materials in an abundance of accessible adsorption sites with high affinity to achieve both fast adsorption kinetics and increased adsorption capacity for toxic contaminants. The removal of pollutants by mesoporous silica adsorbents is now in the limelight due to the nontoxicity and biocompatibility of these materials with the environment. In this study, a fibrous core-shell magnetic mesoporous composite (Fe3O4/SiO2/KCC-1) was successfully synthesized and used as a nano-adsorbent to remove Pb(II) from an aqueous solution. The adsorbent was characterized by employing TEM, SEM, FTIR, VSM, XRD, and N2 adsorption–desorption techniques. According to the results, Fe3O4/SiO2/KCC-1 was successfully synthesized with an average pore diameter of 7.94 nm, a surface area of 813.07 m2 g-1, and a pore volume of 1.41 cm3 g-1. The response surface methodology (RSM) was then adopted in the central composite design (CCD) to optimize parameters of the adsorption process. The optimal conditions for Pb(II) adsorption were then determined at a temperature of 80 °C, an adsorption dosage of 0.04 g L-1, a pH 5.6, and the contact time of 38 min. The removal rate of Pb(II) was 90%. Studies of equilibrium and kinetics indicated that the adsorption process followed Langmuir’s isotherm and the pseudo-first-order model with correlation coefficients of 0.98 and 0.99, respectively. The maximum adsorption capacity of Fe3O4/SiO2/KCC-1 was reported 574.4 mg g-1. Moreover, the thermodynamic parameters known as enthalpy (ΔH° = +5.84 kJ mol-1), negative Gibbs free energy (∆G°) values, and entropy (ΔS° = +23.42 kJ mol-1 K-1) indicated that the adsorption was endothermic and spontaneous with the increased disorder at the solid–liquid interphase

Food Quality Monitoring Based on Hydrolysis-Induced Au-Catalyzed Heck Cross-Coupling by Ag Metallization

Visual detection of meat spoilage was performed based on hydrolysis-induced silver metallization on gold nanoparticles (Au NPs). The hydrolysis of 4-I-benzene-bounded Wang resin was induced by the release of a biogenic amine followed by Au-catalyzed Heck cross-coupling reaction that made silver-coated gold core-shell NPs (Au@Ag) in the presence of Ag ions (Ag metallization). A portable sensory cap was designed by this hypothesis and the successful results were obtained for histamine, trimethylamine, and a spoilage sheep meat. With this protocol, the localized surface plasmon resonance (LSPR) is tuned for absorption of Au NPs and leads to LSPR peak blue shift of gold nanoparticles due to the Ag metallization and the preparation of Au@Ag core-shell NPs. Au NPs and the resulting Au@Ag NPs were characterized by transmission electron microscopy (TEM), BET, ultraviolet-visible (UV-Vis), X-ray diffraction (XRD), energy dispersive X-ray (EDX), and dynamic light scattering (DLS) analyses. Also, various control experiments were set up to credit the portable sensory tube

Application of green synthesized biogenic Nd2Zr2O7 supported on dendritic fibrous nano-titanium for photocatalytic and antibacterial activities

The combination of a phase junction and fibrous structure has been proven to improve the catalytic ability and performance, as well as the separation of nano titanium oxide. However, there is still a pressing need for facile and environmentally sustainable fabrication techniques. In this research, we introduce an innovative approach for the fabrication of dandelion-like TiO2 with anatase/TiO2 phase interfaces and an extremely specific exterior layer using a user-friendly and green deep eutectic solvent-tuning method. We have successfully synthesized DaNd2Zr2O7 nanospheres on dendritic fibrous nanotitanium (DFNT@DaNd2Zr2O7) using a straightforward method. The DFNT@DaNd2Zr2O7 composite retained its mesoporous structure and crystalline morphology, despite the loading of DaNd2Zr2O7. These nanocomposites are employed as active photocatalysts under UV radiation and can effectively treat water contaminated with organic pollutants and microorganisms. Additionally, they exhibit antimicrobial properties against gram-positive species like pathogenic strains of Enterococcus faecalis and Staphylococcus aureus, as well as Gram-negative species like Escherichia coli, Furthermore and Klebsiella pneumonia, these nanocomposites exhibit excellent stability over ten cycles, reinforcing their potential as proficient catalysts to address environmental concerns

Chemical Composition of Hexane Extract of Different Parts of Anthemis talyschensis and its Potential to Use in Sunscreen Products

In this study, both the presence and concentration of some unsaturated compounds in hexane extracts of different parts of Anthemis talyschensis showing absorption at wavelength 280-450 nm were surveyed, with the view of possibly using extracts of this plant in new formulations of sunscreen creams. The hexane extracts of flower, leaf and stem of A. talyschensis, collected from Northwest Iran, were obtained using a Soxhlet apparatus. The fatty acids were derivatized to methyl esters and were determined by gas chromatography/flame ionization detector (GC/FID) and gas chromatography/mass spectrometry (GC/MS) systems. The chemical analysis resulted in identification of 14, 9 and 29 constituents, comprising about 99.5, 97.1 and 98.2% of the total constituents in hexane extracts of flower, leaf and stem, respectively. The main unsaturated constituents in the hexane extract of A. talyschensis flower were 9, 12-octadecadienoic acid, 9-octadecenoic acid and 6, 9, 12-octadecatrienoic acid; while the leaf's extract contained 9, 12-octadecadienoic acid and 9-octadecenoic acid; no unsaturated compounds were detected in the stem. The ratios of unsaturated fatty acid /saturated fatty acid were 13.6, 9.3 and 0 in extracts of the flower, leaf and stem, respectively, but the total amounts in the leaf were much greater. It can be concluded the leaf extract is more likely to be suitable for producing sunscreens creams than others

Probing the interaction behavior of Nano-Resveratrol with α-lactalbumin in the presence of β-lactoglobulin and β-casein: spectroscopy and molecular simulation studies

The main purpose of this research was to evaluate the role of α-lactalbumin (α-LA), β-lactoglobulin (β-LG), and β-Caseins (β-CN) in the binding interaction between Nano Resveratrol (Nano Res), as binary and ternary systems. This investigation was fulfilled through the application of multi-spectroscopic, transmission electron microscopy (TEM), field emission scanning electron microscope (FE-SEM), conductometry, isothermal titration calorimetry (ITC), and molecular dynamics (MD) simulation techniques. Fluorescence spectroscopy observations illustrated the effectiveness of Nano Res throughout the quenching of α-LA, (α-LA-β-LG), and (α-LA-β-CN) complexes, confirming the occurrence of interaction through the combination of static and dynamic mechanisms. An enhancement in the temperature of all three complexes caused a decrease in their Ksv and Kb values, which indicates the static and dynamic behavior of their interactions. The obtained thermodynamic parameters proved the dominance of electrostatic interaction as the binding force of both binary and ternary systems. The observed properties of Tyr or Trp residues in proteins through the data of synchronous spectroscopy at Δλ = 15 and 60 nm, respectively, demonstrated the closer positioning of (α-LA-β-CN) complex to the proximity of Trp residues when compared to the two other cases. According to the resonance light scattering (RLS) measurements, the detection of a much greater RLS intensity in (α-LA-β-CN) Nano Res complex suggested the production of a larger complex. Furthermore, the conductometry outcomes displayed an increase in molar conductivity and therefore approved the occurrence of interaction between Nano Res and proteins in both binary and ternary systems. The spherical shape of Nano Res was confirmed through the results of FE-SEM and TEM analyses. The conformational changes of proteins throughout the binding of Nano Res was evaluated by circular dichroism (CD) technique, while molecular docking and MD simulations affirmed the binding of Nano Res to α-LA, (α-LA-β-LG), and (α-LA-β-CN) complexes as binary and ternary systems. These In Silico study data confirm the results of in vitro assessments. The occurrence of changes in the secondary structure of β-galactosidase was implied through the increased enzyme catalytic activity induced by the interaction of different lactose concentrations. Communicated by Ramaswamy H. Sarma</p