Silver nanoparticles were synthesized using Euphorbia Confinalis stem extract which is an eco-friendly and cost effective method compared to other synthesis protocols like chemical and physical methods. Euphorbia Confinalis which is used traditionally for therapeutic uses was responsible for capping and reducing silver ions to silver nanoparticles. Silver was of a particular interest for this process due to its evocative physical and chemical properties. The silver nanoparticles synthesized were quantified and characterized using visual examination of the color changes, UV-Visible spectroscopy, Scanning Electron Microscopy, Transmission Electron Microscopy, Dynamic Light Scattering and Fourier Transform Infrared spectroscopy. The antimicrobial activity of the synthesized nanoparticles was done by agar disc diffusion method tested against Escherichia coli (Gram-Negative) and Staphylococcus aureus (Gram-Positive). The synthesis of silver nanoparticles was confirmed by color change of AgNO3 to reddish brown upon addition of the Euphorbia Confinalis stem extract. The UV-Vis spectrum showed broad absorption band at 433nm corresponding to that of Surface Plasmon Resonance of silver nanoparticles. The FTIR analysis showed the presence of aromatic, aliphatic and amines and these observations suggested the presence and binding of organic compounds with silver nanoparticles.

The synthesis of silver nanoparticles by using the stem extract and leaf extract of Sclerocarya birrea (Marula) and silver nitrate (AgNO 3) is reported. The synthesized nanoparticles were characterized using ultraviolet-visible spectroscopy, transmission electron microscopy, energy-dispersive X-ray spectroscopy, dynamic light scattering, and visual inspection. The antibacterial activity of the synthesized nanoparticles was done by agar disc diffusion method and tested against Escherichia coli (Gram-negative) and Staphylococcus aureus (Gram-positive). The ultraviolet visible absorption spectrum showed broad absorption band at around 430 nm corresponding to that of surface plasmon resonance of silver nanoparticles. The synthesis of silver nanoparticles was also confirmed by color change of AgNO 3 to reddish brown upon addition of Sclerocarya birrea stem and leaf extracts. In addition, change in color of the solution from colorless to brown within 5 min at pH 11 showed that the rate of reduction was faster at this pH compared to lower pH. Transmission electron microscopy analysis proved that the synthesized nanoparticles were spherical in shape; energy-dispersive spectroscopy analysis confirmed the presence of silver in the synthesized nanoparticles; and dynamic light scattering confirmed that the stem nanoparticles were generally larger (36 to 58 nm) than those synthesized from leaf extracts (32 to 48 nm). These nanoparticles were found to possess potential antibacterial activity against E. coli and S. aureus.

This research article presents a comparative study of the adsorption properties of Moringa oleifera biomass using Pb 2+ ions as test analyte. The investigated parameters which affected the adsorption process were the effect of pH, initial concentration, adsorbent dose, contact time, and temperature. The comparison of adsorption process was evaluated in the pH range of 3 to 8, concentration range from 5 to 20 ppm, temperature varied from 25 to 80°C, variation of contact time from 15 to 80 min, and dose of the adsorbent from 0.3 to 1.2 g. The results obtained showed that a high adsorbent dose is required for high adsorption capacity. The pH of 7 was most effective with temperature set at 25°C and contact time of 60 min. The Temkin, Dubunin-Radushkevich, Langmuir and Freundlich isotherms were applied and fitted well to the data and values of the parameters of these isotherm equations were calculated. The Langmuir isotherm proved to be the overall best isotherm. The adsorbent surface functional groups were identified with Fourier Transform Infrared (FTIR) spectroscopy. The maximum adsorption capacity obtained was 98% for seed, 96% for blended, 94% for pods, and 92% for leaves. Better thermodynamic and kinetic properties were obtained with the seeds and the blended samples. In total, these results indicate that the blended moringa biosobent can be employed as a low-cost biosorbent for the removal of lead ions from water.

An oil-in-water nanoemulsion comprising of aluminium ions encapsulated in a chemically modified starch derivative was prepared, characterised and evaluated for the antimicrobial activity. The nanoemulsion was prepared by emulsion-coacervation method under ultrasonication conditions. Based on the aluminium oxinate chelate of Al 3+ ions, Al(ox) 3 , the encapsulation efficiency (92%) was determined by ultraviolet-visible spectrometry measured at 365 nm, and the subsequent drug loading efficiency was also calculated to be 92%. Fourier transform infrared spectroscopy confirmed the formation of carboxymethyl starch, and the degree of substitution was found to be 0.17 by back-titration, using phenolphthalein as an indicator. Transmission electron microscopy (TEM) micrographs revealed spherical nano-droplets with a minimum particle diameter of 7 nm that had coalesced to form nano aggregates of variable diameters. There was also an indication of the formation a larger nano cluster with a length of approximately 215 nm. Freeze-thaw cycles revealed that the nanoemulsion was stable. Disc diffusion method was used to evaluate the antimicrobial activity of the synthesized aluminum ion nanoemulsion on selected gram-negative bacteria (E. coli and P. aeruginosa) and grampositive bacteria (B. subtilis and S. aureus).