Green Synthesis of Silver Nanoparticles Using Aloe vera L. and Screening Its Activity Against Gram Negative Bacteria

Abstract

The current research was done to produce silver nanoparticles by green synthesis from Aloe vera leaf extract to evaluate the antibacterial properties against gram-negative bacteria (Klebsiella pneumoniae, Escherichia coli, Proteus mirabilis and Acinetobacter baumannii). Atomic Force Microscopy (AFM) was used to determine the average size and form of the nanoparticles which was 55 nm. Scanning electron microscopy (SEM) shows the Ag NPs 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 Ag NPs 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 Ag NPs (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 P. mirabilis, K. pneumoniae, E.coli, A. baumannii were (23, 22, 21 and 20)mm respectively at concentration(100) mg/ml and the lowest zone at concentration (12.5)mg/ml at the same isolates were (13, 12, 10 and10) mm.