Biosynthesis and characterization of silver nanoparticles by Aloe vera leaves extract and determination of its antibacterial activity

The current research aimed to produce Silver nanoparticles by green synthesis from Aloe vera leaf extract which was a crucial field because of its cost-effectiveness, environmental friendliness, and low toxicity and evaluating the antibacterial properties against gram-positive bacteria (Staphylococcus epidermidis and Staphylococcus aureus) and gram-negative bacteria (Pseudomonas aeruginosa and Acinetobacter baumannii). The nanoparticles were characterized using Atomic Force Microscopy (AFM) that was used to determine the average size and form of the nanoparticles which was 55 nm. Scanning electron microscopy (SEM) show the AgNPs have a spherical and smooth surface region. UV– visible spectroscopy (UV-Vis) was used to measure the wavelength range, which showed a sharp peak at 450 nm. X-ray Diffraction (XRD) which show the AgNPs have three strongest peaks, the measured particle sizes were 15.4 and 18.3 and 22.1 nm. Different functional groups of biomolecules are responsible for the reduction and capping processes, as shown by Fourier Transform Infrared Spectroscopy (FTIR). Different concentrations of AgNPs (12.5, 25, 50 and100) mg/ml were examined against multiple drug resistance (MDR) isolates, and the results showed the highest diameter of inhibition zone against S. aureus, S. epidermidis, A. baumannii and P. aeruginosa were (22, 23, 20 and 21) mm respectively at concentration (100) mg/ml and the lowest zone at concentration (12.5) mg/ml at the same isolates were (12, 11, 10 and10) mm respectively.