Silver nanoparticles biosynthesized by secondary metabolites from Moringa oleifera stem and their antimicrobial properties

Abstract

Biological extracts have recently shown a great potential for rapid biosynthesis of silver nanoparticles (AgNPs) with antibacterial activity. AgNPs were synthetized by reduction effect of secondary metabolites produced by the Nigrospora sp. fungus, from Moringa oleifera stem as a reducing agent and silver nitrate (AgNO 3 ) (1 mM) as salt precursor. The synthesis of nanoparticles (NPs) was monitored through analysis of the UV-Vis spectroscopy absorption in the 436 to 440 nm range indicating the presence of AgNPs in the colloidal aqueous solutions. Fourier transform infrared spectroscopy (FTIR) spectra were performed to identify the compounds responsible for the bio reduction of the Ag + . The morphology and sizes of AgNPs were characterized by scanning electron microscopy (SEM), energy dispersive of X-ray spectroscopy (EDS), dynamic light scattering (DLS), and colloid stability by zeta potential measurements. The NPs obtained were spherical in shape with size in the 3 to 70 nm range. Antibacterial activity was confirmed by evaluation of their effect against Escherichia coli, Klebsiella cloacae and Staphylococcus epidermidis. The proposed green synthesis of AgNPs from secondary metabolites produced by the Nigrospora sp. fungus from M. oleifera stem can be strongly recommended as a potential method for biomedical application.

Green synthesis of silver nanoparticles using plant extracts and their antimicrobial activities: a review of recent literature

“…Plants stem extract was widely utilized as a reducing agent for the green synthesis of AgNPs ( Table 3 , entries 46–53). Aqueous extract of Moringa oleifera , 258 waste grass 259 and Swertia paniculate 260 have been utilized for the bio-synthesis of AgNPs to investigate its antimicrobial activity against various bacterial strains. It is reported that the waste grass mediated AgNPs are smaller in size (15 nm) compared to Moringa oleifera and Swertia paniculate mediated AgNPs, hence AgNPs obtained from waste grass extract shows greater antimicrobial activity as it can easily disrupt the bacterial cell wall.…”

A comprehensive review on Moringa oleifera nanoparticles: importance of polyphenols in nanoparticle synthesis, nanoparticle efficacy and their applications

“…M. oleifera stem bark extract was used for stable formation of AgNPs which can be used for the treatment of cancer [ 37 ]. AgNPs produced biologically by the reducing action of secondary metabolites found in the stem of M. oleifera , exhibited great potential for rapid synthesis of NP with antibacterial activity [ 61 ].…”

“…The uptake of spherical particles by human endothelial cells was the highest and that of hollow particles [ 115 ]. The AgNPs synthesized from M. oleifera leaf extract, which was spherical in shape expressed remarkable antimicrobial action, preventing the growth of S. epidermidis, K. cloacae, and E. coli [ 61 ]. The rod and cube shaped AgNPs, showed significant difference of growth reduction for the two studied fungi.…”

Bioinspired and Green Synthesis of Silver Nanoparticles for Medical Applications: A Green Perspective

“…Several studies in the past decade have successfully demonstrated the synthesis of AgNPs using stem extracts from plants like Caesalpinia pulcherrima [ 61 ], Anthemis atropatana [ 62 ], Moringa oleifera [ 63 ], Dorema ammoniacum [ 64 ], Swertia paniculata [ 65 ] and others. In a 2018 study, Khatami and colleagues synthesized AgNPs with an average size of 15 nm from waste dried grass [ 66 ] (Fig.…”