Biosynthesis of silver nanoparticles using upland cress: purification, characterisation, and antimicrobial activity

Abstract

Silver nanoparticles have traditionally been synthesised using physical and chemical methods, often requiring expensive equipment and reagents that pose risks to the environment. This work provides a green method for the biosynthesis of silver nanoparticles using leaf extracts from upland cress: Barbarea verna. Natural reducing agents within the leaf extracts of upland cress reduce silver ions from silver nitrates, resulting in the formation of silver nanoparticles. The silver nanoparticles were purified using centrifugation and extraction using Triton X-114. The resulting nanoparticles were characterised using UV-Vis spectroscopy, dynamic light scattering, atomic force microscopy, and scanning electron microscopy. Silver nanoparticles were shown to have a diameter of 30-40 nm with a characteristic UV-Vis absorption peak at 420 nm. Antimicrobial properties of the synthesised silver nanoparticles were also confirmed using S. epidermis and E. coli bacteria.

Green Synthesis of Gold Nanoparticles Using Upland Cress and Their Biochemical Characterization and Assessment

“…When plants contain higher total phenolic content, they possess stronger antioxidant activity [ 25 ]. Ascorbic acid also contributes to high levels of antioxidant capacity of upland cress [ 19 ]. Hence, it is critical to determine the total phenolic and ascorbic acid content.…”

“…To improve the extraction efficiency and consistency of the synthesis process, the previous procedure [ 19 ] was modified. Specifically, blending was used to prepare the ex-tract rather than boiling, as boiling showed inconsistencies.…”

“…The green synthesis and purification protocols( Scheme 1 ) were based on previous work [ 19 ] with modifications, in the extraction process (blending instead of boiling was used). Briefly, 10 g of upland cress were blended in 100 mL deionized (DI) water for 15 s. The mixture was then vacuum filtered twice using Whatman filter paper and centrifuged at 4000 rpm for 5 min to produce the extract (supernatant).…”

“…For purification, sonication and two more solvents were utilized to achieve a more thorough process in comparison to previous work [ 19 ]. The nanoparticles were collected through centrifugation (4000 rpm, 20 min).…”

“…Phenolics and other plant metabolites (such as sugars and enzymes) are responsible for stabilization and capping [ 18 ]. Recently, upland cress has been used to successfully synthesize silver nanoparticles [ 19 ]. In this work, a novel green synthesis process to produce gold nanoparticles (Au NPs) using upland cress, for different applications from silver nanoparticles, was developed and optimized.…”