Optimized Biosynthesis and Antifungal Activity of Osmanthus fragrans Leaf Extract-mediated Silver Nanoparticles

Abstract

With the development of nanoscience and nanotechnology, increasing research focuses on synthesis, characterization and application of silver nanoparticles. Reported here is the synthesis of silver nanoparticles using Osmanthus fragrans leaf extract, as well as several optimized synthesis parameters, including quantity of fern leaves, concentration of AgNO3, pH, and regulation of reaction temperature. Antifungal activity of silver nanoparticles on Bipolaria maydis (AH-B06) was measured through colony formation and inhibition zone methods. The optimal biosynthesis system contained 5 g of fern leaf and 1 mM AgNO3 at pH 9.0 and 60°C. Under said conditions, the resulting synthesized nanoparticles were nearly spherical, with an average size of 20 nm. In tests, silver nanoparticles synthesized at different concentrations of AgNO3 inhibited colony formation to varying degrees, resulting in different inhibition zones. No colony formed on PDA plates at AgNO3 concentrations at or over 2 mM, while quantity of herbal component was unchanged. Regarding inhibition zones, diameters increased gradually at AgNO3 concentrations from 1-8 mM, while antifungal effect reached maximum at 5 g of herbal component. Results of this study offer a new approach and novel material for comprehensive control pathogenic fungi on plants. As well, the presented method and material have potential application for screening novel fungistats with high efficiency and low toxicity, thus offering a green chemistry answer to a worldwide need.

Biosynthesis of AgNPs by B. maydis and its antifungal effect against Exserohilum turcicum

“…AgNPs synthesised through different methods, microorganisms or plants showed different inhibition activity against the same pathogen [31, 32, 34]. In addition, the antimicrobial activity of AgNPs was influenced by other parameters such as the pH of the solution [28], the stabiliser [38], and the modified substances [19, 30]. These results may offer a novel approach for the comprehensive control of phytopathogens, and it also avoids pathogen resistance to the utmost extent.…”

“…During the past years, various living organisms were applied to synthesise AgNPs; for example, Bacillus koriensis [11], Bacillus sp. [15], Fusarium oxysporum [23], Trichoderma viride [13], Aspergillus fumigatus [16], Septoria apii [14], Pulicaria gnaphalodes [24], Caulerpa racemosa [25], Brassica rapa L. [26], Ginkgo biloba [27], and Osmanthus fragrans [28]. In recent years, animal species such as arthropods and metabolites [29], bio-resources as agro-wastes, enzymes, and pigments were also used to synthesise AgNPs [30].…”

Biomedical Applications of Chinese Herb-Synthesized Silver Nanoparticles by Phytonanotechnology

“…Another study reported on the first use of Osmanthus fragrans leaf extract in the biosynthesis of AgNPs and analyzed and compared its antifungal activity to Tebuconazole (fungicide). AgNPs mediated by O. fragrans leaves had a better inhibitory effect on Bipolaria maydis when compared with a high efficient fungicide, Tebuconazol [ 141 ]. For optimal synthesis, several parameters that influence the synthesis of AgNPs were regulated.…”

Optimised green synthesis of copper oxide nanoparticles and their antifungal activity

“…With the concept of green chemistry deeply rooted in people's minds, the biological synthesis method mediated by microorganisms or plant tissues has become more and more popular. It exhibits several advantages, compared with a physical or chemical method such as eco-friendly, low cost, low energy, high output, high stability, and so forth [6]. In recent years, copper oxide (CuO) nanoparticles were biosynthesised by plant extract of Bifurcaria bifurcate [7], Convolvulus percicus [8], Stachys lavandulifolia [9], Gloriosa superb [10], and so forth.…”