No abstract

Recently, plant-mediated route or green approach for preparing metal and metal oxide nanoparticles has received enormous attention due to the ease of preparation and environmental friendliness when compared to physical and chemical methods. Plants contain phytochemicals which have been proposed as bio-reductants and capping agents for forming metal nanoparticles. Therefore, this study was aimed to prepare magnesium oxide nanoparticles (MgONPs) using aqueous extract of Manihot esculenta leaf. The leaf extract was first analyzed in a gas chromatograph-mass spectrometer (GC-MS) to examine the phytochemicals present. Then, the MgONPs formed were evaluated using UV-Visible (UV-Vis) spectrophotometry, scanning electron microscopy (SEM), energy-dispersive X-ray analysis (EDX), transmission electron microscopy (TEM), X-ray diffractometry (XRD) and Fourier transform infrared (FTIR) spectroscopy, to confirm the formation of MgONPs and to determine the morphology, elemental composition, shape and size, phase composition and nature of bonds present in the sample. Results revealed the formation of monodisperse, hexagonal shaped MgONPs of average size 36.7 nm having potentials for application in catalysis and as antimicrobial agent. Hence the process reported herein could be optimized for large-scale preparation of MgONPs.

No abstract

No abstract

The current work investigated the green and low-cost preparation of silver nanoparticles (AgNPs) using the aqueous extract from Launaea taraxacifolia leaf and studied its antimicrobial effects. The leaf extract was analysed in a gas chromatogrammass spectrometer to assess the phytochemicals present. UV-Vis spectrophotometer was used to monitor the formation of AgNPs, the morphological assessment was performed by a scanning electron microscope, energy dispersive X-ray analysis was used to determine the elemental composition, the particle size and shape were studied using transmission electron microscopy, and the vibrational modes of bonds in the AgNPs were assessed by Fourier transformed infrared spectroscopy. The AgNPs produced were spherical and in a size range of 9-15.5 nm, monodispersed with a large surface area. The minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) of the AgNPs against Pseudomonas aeruginosa and Proteus mirabilis were very low. Against P. aeruginosa, the MIC was 0.10 mg/mL and the MBC was 0.15 mg/mL, while the MIC and MBC against P. mirabilis were 0.05 and 0.25 mg/mL, respectively. Therefore, the AgNPs prepared using L. taraxacifolia leaf extract showed high antibacterial activities and could be a candidate antimicrobial agent for biomedical applications.