Characterization of biosynthesized silver nanoparticles by Haplophyllum tuberculatum plant extract under microwave irradiation and detecting their antibacterial activity against some wastewater microbes
Eslam Ibrahim El-Aswar, Seleem El-Sayed Gaber, Moustafa Zahran, Abdelaleem Hassan Abdelaleem
Abstract
ABSTRACT Silver nanoparticles (AgNPs) were successfully fabricated by utilizing AgNO 3 as a metal precursor and aqueous extract of Haplophyllum tuberculatum extract (HTE) as a source of bioreducing and capping agents through controllable microwave irradiation. Influence of different parameters including pH, HTE volume, silver nitrate concentration, incubation time, and temperature were also discussed. The morphological characteristics were investigated using high resolution transmission electron microscopy, energy-dispersive X-ray spectroscopy, and X-ray diffraction, while the functional groups of bioreducing agents and their efficacy for nanoparticles stabilization were determined using Fourier transform infrared spectroscopy and zeta potential, respectively. Electrochemical behavior of the nanoparticles was studied using cyclic voltammetry (CV) while the optical features were determined using ultraviolet-visible and fluorescence emission spectroscopy. The results indicated that the nanoparticles are semispherical with an average size of 40 nm. These particles have considerable stability confirmed by zeta potential value (–45 mV) and also electrochemically detected at 424 mV. On the other hand, the nanoparticles showed antibacterial activity against total and fecal coliform bacteria. Also, the antibacterial activity of biosynthesized AgNPs against Staphylococcus aureus, Bacillus subtilis, Escherichia coli, and Klebsiella pneumoniae was evaluated. Overall, our biosynthesized AgNPs could be used in developing the treatment techniques of wastewater.