Green Synthesis of Silver Nanoparticles with Antibacterial Activity Using Various Medicinal Plant Extracts: Morphology and Antibacterial Efficacy

Abstract

A green synthetic route for the production of silver nanoparticles (AgNPs) using five different aqueous plant extracts, namely, Berberis vulgaris, Brassica nigra, Capsella bursa-pastoris, Lavandula angustifolia and Origanum vulgare, was investigated in this study. The present work demonstrates the influence of plant extract composition (antioxidant and total phenolic content) on the size and morphology of the produced AgNPs. The biosynthetic procedure was rapid and simple and was easily monitored via colour changes and ultraviolet and visible (UV-Vis) spectroscopy. Subsequently, measurement of zeta potential (ZP), photon cross-correlation spectroscopy (PCCS), X-ray diffraction (XRD), Fourier-transform infrared spectroscopy (FTIR), transmission electron microscopy (TEM) and selected area electron diffraction (SAED) analysis were employed to characterise the as-synthesised nanoparticles. The XRD investigation confirmed the presence of Ag0 in the nanoparticles, and interactions between the bioactive compounds of the plants and the produced AgNPs were evident in the FTIR spectra. TEM indicated that the nanoparticles exhibited a bimodal size distribution, with the smaller particles being spherical and the larger having a truncated octahedron shape. In addition, the antimicrobial activity of the AgNPs was tested against five bacterial strains. All synthesised nanoparticles exhibited enhanced antimicrobial activity at a precursor concentration of 5 mM compared to the control substance, gentamicin sulphate, with the best results observed for AgNPs prepared with B. nigra and L. angustifolia extracts.

Mechanochemistry as an Alternative Method of Green Synthesis of Silver Nanoparticles with Antibacterial Activity: A Comparative Study

“…The antibacterial activity is reported in neither of the papers [ 11 , 12 , 13 , 14 ] using the same plant for the Ag NPs. The RIZD values obtained for the samples LEV-Ag-GS-0.99 and 5.95 are in accordance with those reported in [ 47 ], where the values above 90% for concentration 5 mM AgNO 3 and above 80% for the concentration 2.2 mM AgNO 3 were reported. The antibacterial activity of lavender essential oil is widely known and is also a focus of recent research [ 72 , 73 , 74 ].…”

“…Surprisingly, the RIZD values obtained for green synthesis were almost completely in line with the calculated values for E. coli and were slightly lower, but still close, to those detected for S. aureus . In general, the RIZD values of both in a recent study and [ 47 ] were slightly lower for E.coli .…”

“…For example in [ 46 ], the authors did not observe the reflections of Ag 0 , just the ones belonging to AgCl (although in this case, another type of lavender, namely Lavandula dentata L. leaves have been used). In our recent paper where different plants, including Lavangula angustofolia L. have been used [ 47 ], AgCl has been detected by selected area diffraction (SAED) used with transmission electron microscopy (TEM). In other studies, no mention about AgCl is provided [ 11 , 12 , 13 ].…”

Green Synthesis, Characterization, and Antibacterial Properties of Silver Nanoparticles Obtained by Using Diverse Varieties of Cannabis sativa Leaf Extracts

“…The reduction of Ag + ions into Ag 0 nanoparticles was easily observed via the distinct color change from yellow-pale green to reddish and dark brown, respectively, due to the surface plasmon resonance phenomena. The best reaction conditions (the concentration of AgNO 3 solution, the plant extract:AgNO 3 solution ratio, the temperature, and the reaction time) for each plant extract that mediate the AgNPs synthesis should be investigated, and one recent article revealed these conditions for the following five plant extracts: Berberis vulgaris (root extract), Brassica nigra (seed extract), Capsella bursa-pastoris (leaves extract), Lavandula angustifolia (leaves extract), and Origanum vulgare (leaves extract) [ 40 ], and other articles presented the results related to Cannabis sativa extracts (hemp herd [ 37 ], leaf extracts [ 36 , 39 ], and hemp stem extracts [ 38 ]). To examine the formation of AgNPs UV−VIS spectroscopy experiments were conducted ( Figure 1 ).…”

Transcriptome Profile Alterations with Carbon Nanotubes, Quantum Dots, and Silver Nanoparticles: A Review

“…While silver is found in many daily activities, AgNP production and application have potentially toxic effects to both the environment [ 55 ] and the human population. Recently, “green” synthesis of AgNP using plants and microorganisms has been explored as an eco-friendly alternative ( Table S3 ) [ 55 , 56 , 57 , 58 , 59 ]. In humans, AgNP exposure has been linked to disrupting the function of mitochondria, sperm cells, and cytokine expression [ 47 ].…”