“Miswak” Based Green Synthesis of Silver Nanoparticles: Evaluation and Comparison of Their Microbicidal Activities with the Chemical Synthesis

Abstract

Microbicidal potential of silver nanoparticles (Ag-NPs) can be drastically improved by improving their solubility or wettability in the aqueous medium. In the present study, we report the synthesis of both green and chemical synthesis of Ag-NPs, and evaluate the effect of the dispersion qualities of as-prepared Ag-NPs from both methods on their antimicrobial activities. The green synthesis of Ag-NPs is carried out by using an aqueous solution of readily available Salvadora persica L. root extract (RE) as a bioreductant. The formation of highly crystalline Ag-NPs was established by various analytical and microscopic techniques. The rich phenolic contents of S. persica L. RE (Miswak) not only promoted the reduction and formation of NPs but they also facilitated the stabilization of the Ag-NPs, which was established by Fourier transform infrared spectroscopy (FT-IR) analysis. Furthermore, the influence of the volume of the RE on the size and the dispersion qualities of the NPs was also evaluated. It was revealed that with increasing the volume of RE the size of the NPs was deteriorated, whereas at lower concentrations of RE smaller size and less aggregated NPs were obtained. During this study, the antimicrobial activities of both chemically and green synthesized Ag-NPs, along with the aqueous RE of S. persica L., were evaluated against various microorganisms. It was observed that the green synthesized Ag-NPs exhibit comparable or slightly higher antibacterial activities than the chemically obtained Ag-NPs.

Secondary Metabolites in the Green Synthesis of Metallic Nanoparticles

“…In addition to being eco-friendly, NPs can be synthesized using agricultural and industrial waste to make the process more sustainable [ 15 , 16 ]. GNPs often possess better bioactivities [ 17 , 18 , 19 , 20 ] and catalytic characteristics compared to their counterparts, which are synthesized by other methods [ 21 , 22 ]; this is probably a result of the compounds attached to their surface [ 14 ]. The ability of plant secondary metabolites to bind or conjugate with NPs upon green synthesis could be exploited for the purification of compounds and drug discovery.…”

<p>Silver Nanoparticles for the Therapy of Tuberculosis</p>

“…The highly-negatively charged bacterial wall is believed to be an important fact in explaining the superior activity of AgNP against G-compared with G+ bacteria which is frequently reported. 158 In a similar study, positively charged AgNP by functionalization with PHMB functionalized exhibited superior antibacterial effects against E. coli. Also, the bactericidal activity of PHMB was enhanced by the combination with AgNPs.…”

“…191 Also, a study which compares the antibacterial effect of AgNP produced by green synthesis (from S. persica) versus chemical against Gram-negative (E. coli and P. aeruginosa) and Gram-positive (M. luteus and S. aureus) bacteria shows that the green synthesized Ag-NPs exhibited slightly higher antimicrobial activity in comparison to the chemically synthesized Ag-NP. 158 The conclusion of the study was that, although S. persica root has antibacterial properties per sei, due to the small amount of active compound included in the synthesis process, the increased activity of the green-synthetized Ag-NPs was mainly due to the improved solubility of the Ag-NPs rather than the microbicidal potential of plantderived compounds used for the synthesis of NPs.…”

Green Synthesis of Silver Nanoparticles by Using Salvadora persica Leaf Extract and Evaluation of Their Antifungal Activities

“…The concentration of these compounds are very important to reducing Ag+ to Ag 0 and also the size of silver nanoparticles. [2][3][4][5][6][7] The result showed silver nanoparticels have a good activity against fungi even better than other treatment. The average results of treatments was showed the highest antifungal activity of treatments respectively related to silver nanoparticle (16.56 mm), co-trimaxozol (13.16 mm), ethanolic extract of Salvadora persica leaf (12.27 mm) and silver nitrate (10.33 mm).…”

“…The results showed that silver nanoparticles synthesized have favorable antibacterial activities. [1][2][3][4][5][6] In present study we used the ethanolic extract of Salvadora persica leaf and silver nitrate solution for synthesis silver nanoparticles and also the antifungal activities of silver nanoparticles and ethanolic extract of Salvadora persica leaf against Aspergillus niger and Penicillium digitatum by disk diffusion method were investigated.…”