Iranian Journal of Materials Science and Engineering

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ABSTRACT
In this paper, novel Nanohybrid CuO-Fe₃O₄/Zeolite nanocomposites (HCFZ NCs) have been synthesized to improve the adsorption capacity and activity for removing the Arsenic and Lead cations from the contaminated water solutions. The nanohybrid 4, 10, and 20 -HCFZ NC samples were investigated by XRD, FT-IR, TEM, FESEM, EDX, and BET. The characterization results of these catalysts confirmed the presence of CuO and Fe₃O₄ NPs in nanospherical shapes as Nanohybrid Cu and Fe oxides on the zeolite surface. Notably, the 10-HCFZ NC sample showed the highest removal efficiency of harmful metallic pollutants from the water in comparison to the prepared neat zeolite, 4-HCFZ NC, and 20-HCFZ NC samples, with a percentage removal of (97.9 %) for Pb ions and (93.5 %) for As ions within 30 minutes (100 ppm). According to the adsorption isotherms results, R² values for the Langmuir isotherm were the highest, suggesting that the experimental results fit better the Langmuir isotherm model. Generally, according to the obtained results, there is a possibility of enhancing the efficiency of Nanohybrid CuO-Fe₃O₄/Zeolite NCs to remove Arsenic and Lead ions from polluted aqueous solutions.
 

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Graphene Nanoparticles (GNPs), an upshot of nanotechnology have attracted great interest in diverse research fields including dentistry for their unique properties. Graphene Nanoparticles are cytocompatible and when combined with other compounds, they possess improved synergistic antimicrobial and anti-adherence properties against oral pathogens. The cytotoxicity of graphene in the oral setting has been reported to be very limited in the scientific literature. Current applications of graphene include reinforcing Polymethylmethacrylate (PMMA) for the fabrication of dentures, improving properties of dental luting agents like glass ionomer cement, reinforcing restorative composites and ceramics, and improving osseointegration of titanium dental implants by coating with graphene. This paper reviews the nanoparticle ‘Graphene’ and its potential uses in the field of restorative dentistry.
 

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Iron oxide nanoparticles has attracted extensively due to their supermagnetic properties, preferred in biomedicine because of their biocompatibility and potential nontoxicity to human beings. Synthesis of iron nanoparticles (FeNPs) was prepared with the help of ferric chloride and ferrous sulphate by using the coprecipitation method. The variation and combination of ferric and ferrous concentrations affect the physical and magnetic properties of iron oxide nanoparticles.  The effect of 0.1 M ferric and ferrous concentration on iron oxide nanoparticles studied separately and in combination. The obtained nanoparticles were characterized by Particle size, zeta potential, Ultraviolet (UV-visible), Fourier Transform Infrared Spectroscopy (FTIR), X-ray diffraction (XRD), Scanning electron microscope (SEM), Thermal gravimetric analysis (TGA), and Vibrating-sample magnetometer (VSM) techniques. Particle size was below 200nm and zeta potential was within the limit for all the batches. UV visible spectra at 224 nm, and FTIR exhibit two peaks at 510 and 594 cm-1, indicating iron oxide NPs and XRD confirmed the crystalline nature of Fe. SEM showed a spherical shape for all batches. The use of a combination of ferric and ferrous is more effective than its individual use. TGA and VSM studies confirmed its magnetic properties.
 

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Drug-resistance among bacteria is a concerning issue in medical field. Silver nanoparticles (AgNPs) are one of the promising novel nano-antibiotics. In the present study, AgNPs were synthesized using cell-free extract of Acinetobacter sp. challenged with silver nitrate. Preliminary observations done using UV-Vis spectrophotometry at 420 nm. Complete reduction of silver ions to AgNPs was confirmed through cyclic voltammetry. Electron microscopy revealed formation of spherical shaped nanoparticles of size upto 20 nm. These AgNPs were furthr used to determine their effect on activity of various antibiotics against pathogenic bacteria such as Neisseria and Xanthomonas. Higher antibacterial activity of AgNPs was observed against Gram-negative bacteria. Enhanced antibacterial action of AgNPs was observed with selected beta-lactam antibiotics producing upto 3-fold increase in area of zone of inhibition. On exposure to AgNPs, the minimum inhibitory concentration and minimum bactericidal concentration of antibiotics were lowered by upto 2000 times indicating potential synergistic action of AgNPs. This study clearly signifies that the drug, proved to be inefficient due to bacterial resistance, could be made functional again in presence of AgNPs. This will help in development of novel antibacterial formulations containing antibiotics and nanoparticles to combat multiple drug-resistance in microorganisms.

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Researchers are increasingly focusing on green synthesis methods for silver nanoparticles due to their cost-effectiveness and reduced environmental impact. In this study, we utilized an edible bird's nest (EBN), a valuable economic resource, as the primary material for synthesizing silver nanoparticles using only water as the solvent. Metabolite profiling of the EBN extract was conducted using LC-QTOF-MS in positive mode (ESI+), revealing the presence of lipids, glycosides, peptides, polysaccharides, and disaccharides. Upon the addition of silver nitrate to the aqueous EBN extract, noticeable color changes from transparent to brown indicated the successful formation of AgNPs. Subsequent characterization of these silver nanoparticles involved UV-Visible spectroscopy, which revealed an absorption peak at 421 nm. Further characterization was carried out using FESEM, ATR-FTIR spectroscopy, and EDX analysis. The involvement of phenolic agents, proteins, and amino acids in reducing the silver particles was confirmed. The synthesized nanoparticles exhibited a spherical shape, and a particle size ranging from 10 to 20 nm. The presence of elemental silver was confirmed by a strong, intense peak around 3 keV in the EDX spectrum. To assess their potential, the antibacterial properties of the silver nanoparticles against Escherichia coli and Staphylococcus aureus were evaluated using the agar diffusion method.
 

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Biogenic synthesis of papain-conjugated copper metallic Nanoparticles and their antibacterial and antifungal activities Papain metallic conjugated nanoparticles (Papain-CuNPs) were synthesised using Papain and CuSO4.5H₂O. Papain-CuNPs were characterized using UV-visible spectroscopy, FT-IR, HR-TEM, XRD, FE-SEM, zeta potential, and a zeta sizer. The antibacterial activity of papain-CuNPs against human infectious microorganisms (Citrobacter spp, Pseudomonas aeruginosa and Candida albicans) was investigated. The mechanism of action of papain-CuNPs was evaluated using FE-SEM and HRTM. UV spectroscopy confirmed the plasma resonance (SPR) at 679 nm, which indicated the formation of papain-CuNPs. The FT-IR spectrum absorbance peaks at 3927, 3865, 3842, 3363, 2978, and 2900 cm^-1 indicate the presence of O-H and N-H of the secondary amine, and peaks at 1643 and 1572 cm^-1 represent C=O functional groups in Papain-CuNPs. EDAX analysis confirmed the presence of copper in the papain-CuNPs. The zeta potential (-42.6 mV) and zeta size (99.66 d. nm) confirmed the stability and size of the nanoparticles. XRD confirmed the crystalline nature of the papain-CuNPs. FE-SEM and HRTM showed an oval structure, and the nano particles' 16.71244–34.84793 nm. The synthesized papain-NPs showed significant antibacterial activity against clinical P. aeruginosa (15 mm). MIC 125 µg/ml) showed bactericidal activity against P. aeruginosa and the mechanism of action of Papain-NPs was confirmed using an electron microscope by observing cell damage and cell shrinking. Papain-CuNPs have significant antibacterial activity and are thus used in the treatment of P. aeruginosa infections