We report a facile one-pot green synthesis of zinc oxide (ZnO) nanostructures using aqueous leaf extract of Dolichos Lablab L. as the reducing and capping agent.

Nanotechnology is a recent field of modern research dealing with synthesis, strategy and manipulation of particle’s structure in size range of 1–100 nm. This study introduces one of the methods of synthesis of nanoparticles, i.e., green synthesis of ZnO NPs using aqueous leaf extract of Becium grandiflorum (AM: ‘Yedegamentisie’). The biomolecules of the plant extract (such as phenols, flavonoids, saponins, glycosides, steroids, tannins and alkaloids) were used as capping and reducing agent during synthesis of ZnO NPs. Response surface methodology coupled with Box-Behnken design (RSM-BBD) was used to optimize the synthesis of ZnO NPs and adsorption studies of the as-synthesized ZnO NPs. Then, ZnO NPs was characterized using different spectroscopic and microscopic instruments such as UV–Vis spectroscopy, FTIR, XRD and SEM–EDS to consider its purity, shape and crystallinity. UV–Vis analysis showed peaks in the range 305–312 nm due to synthesis of ZnO NPs. FTIR analysis showed the availability of different phytochemicals in the plant extract and synthesis of ZnO NPs at 490 cm−1. Powder XRD patterns confirmed formation of phase pure wurtzite structures of ZnO NPs. The synthesized ZnO NPs were used to remove MB dye from aqueous solution by acting as a photocatalyst and adsorbent as well as, it also showed antimicrobial activity against two gram positive (Staphylococcus epidermidis, Staphylococcus aureus) and three gram negative (Escherichia coli, Klebsiella pneumonia, Pseudomonas aeruginosa) bacteria.

This work reports synthesis of magnetic rGO/Fe3O4 NCs using pod extract of Dolichos lablab L. as a reducing agent and its applications.

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Copper oxide nanoparticles (CuO NPs) have attracted huge attention due to catalytic, electric, optical, photonic, and antibacterial activity. The use of plant leaf extracts in the biosynthesis of nanostructured materials is an eco-friendly, non-toxic and cost effective approach. Hence, this study aims to provide an updated survey of the main green synthesis method of CuO NPs using leaf extract of Khat, its characterization and studies on antibacterial activities. The synthesis of CuO NPs was done by reducing 1 mM CuSO 4 •5H 2 O with 2% (m/v) aqueous leaf extract of Khat under optimum conditions (pH = 11). The formation of CuO NPs has been confirmed first by the color change from colorless to light green and then to greenish yellow. The kinetics of the reaction was studied using UV-Visible (UV-Vis) spectrophotometer that showed surface plasmon resonance at 333 nm. The CuO NPs exhibit antimicrobial activity against two human pathogens viz. Salmonella typhimurium and Escherichia coli with an average zone of inhibition of 12.5 mm and 8 mm, respectively. Therefore, the current study reveals a convenient utilization of Catha edulis extract as a reducing agent for the successful synthesis of CuO NPs through a green synthesis method to obtain significantly active antibacterial material.