Antimicrobial activity of metal-substituted cobalt ferrite nanoparticles synthesized by sol–gel technique

Therapeutic and diagnostic potential of nanomaterials for enhanced biomedical applications.

Synthesis and characterization of metals-substituted cobalt ferrite [Mx Co(1-x) Fe2O4; (M = Zn, Cu and Mn; x = 0 and 0.5)] nanoparticles as antimicrobial agents and sensors for Anagrelide determination in biological samples

Antibacterial, antibiofilm, and photocatalytic activities of metals-substituted spinel cobalt ferrite nanoparticles.

Biomolecules-mediated synthesis of selenium nanoparticles using Aspergillus oryzae fermented Lupin extract and gamma radiation for hindering the growth of some multidrug-resistant bacteria and pathogenic fungi.

The synthesis and characterization of silver nanoparticles (AgNPs) using natural pigments from plants as reducing agents is presented in this study. The natural pigments were extracted from Alfalfa leaves. The reduction reaction was investigated by UV–Vis and FTIR analyses. The synthesized AgNPs were characterized by UV–Vis, XRD, TEM, and DLS. UV–Vis analysis revealed that AgNPs were produced with a persistent plasmonic absorption peak at about 418 nm accompanied by consumption of pigments. The reduction is suggested to occur, mainly, by chlorophyll a and carotenes. Characterization revealed pure synthesized AgNPs with an average particle size of 25 nm. In an interesting novel experiment, the progress of reduction reaction was traced at the interface between reacting phases under UV illumination making use of fluorescence of both chlorophylls and formed Ag nano-clusters (AgNCs). The enrollment of chlorophylls in reduction was suggested depending on FTIR and fluorescence analyses. The synthesized AgNPs possessed a superior antimicrobial activity towards Staphylococcus aureus ATCC 29213; 24.0 mm ZOI, followed by Escherichia coli ATCC 25922; 17.0 mm ZOI. In addition, AgNPs were a strong antifungal agent against Candida albicans ATCC 10231; 26.0 mm ZOI.

Synthesis of silver nanoparticles using natural pigments extracted from Alfalfa leaves and its use for antimicrobial activity

Extract of Corchorus olitorius stems (ECS) was used as a green inhibitor for the inhibition of mild steel corrosion in 0.5 M H2SO4 solution. GC/MS was used for both qualitative and quantitative analysis of the extract. The corrosion performance of the extract was evaluated using electrochemical impedance spectroscopy, potentiodynamic polarization and weight loss. The results showed that ECS is a mixed-type inhibitor which reduces both anodic and cathodic reactions and the inhibition efficiency was reached up to 93%. Adsorption isotherm data was recorded at different temperatures and analyzed by selected adsorption isotherm models to reveal characteristics of inhibition. Thermodynamic calculations showed that the inhibition efficiency increases with increasing inhibitor concentration, and decreases with increasing temperature. Adsorption of ECS on the mild steel surface was found to be spontaneous and exothermic. Adsorption is suggested to be physisorption according to El-Awady isotherm model. Also, the scanning electron microscopy (SEM) was used to investigate the surface morphology to confirm the corrosion results.

https://iopscience.iop.org/article/10.1088/2053-1591/aa664a/pdf

Mohamed Mokhtar Kotb

Papers

Synthesis of silver nanoparticles using natural pigments extracted from Alfalfa leaves and its use for antimicrobial activity

Green corrosion inhibition of mild steel to aqueous sulfuric acid by the extract of Corchorus olitorius stems