Gold nanoparticles synthesized by Brassica oleracea (Broccoli) acting as antimicrobial agents against human pathogenic bacteria and fungi

Abstract

Production of antimicrobial agents through the synthesis of gold nanoparticles using green technology has been extensively made consistent by various researchers; yet, this study uses the flower bud's aqueous extracts of Brassica oleracea (Broccoli) as a reducing agent for chloroauric acid (1 mM). After 30 min of incubation, synthesis of gold nanoparticles (AuNps) was observed by a change in extract color from pale yellow to purple color. Synthesis of AuNps was confirmed in UV-visible spectroscopy at the range of approximately 560 nm. The SEM analysis showed the average nanoparticles size of 12-22 nm. The antimicrobial activity of AuNps was analyzed by subjecting it to human pathogenic bacteria (Grampositive Staphylococcus aureus and Gram-negative Klebsiella pneumonia) and fungi (Aspergillus flavus, Aspergillus niger and Candida albicans) using disc diffusion method. The broccoli-synthesized AuNps showed the efficient antibacterial and antifungal activity of above-mentioned microbes. It was confirmed that AuNps have the best antimicrobial agent compared to the standard antibiotics (Gentamicin and Fluconazole). When the concentrations of AuNps were increased (10, 25, and 50 lg/ml), the sensitivity zone also increased for all the tested microbes. The synthesized AuNps are capable of rendering high antimicrobial efficacy and, hence, have a great potential in the preparation of drugs used against major bacterial and fungal diseases in humans.

Use of Aqueous Extract of Pseuderanthemum acuminatissimum Radlk Leaves To Mediate The Synthesis of Gold Nanoparticles and Their Anti Eschericia coli Activity

“…It was clear that the current gold nanoparticles in the P. acuminatissimum Radlk leaf extract medium (AuNPs@P. acuminatissimum Radlk leaf extract) represent a potential alternative material for antibacterial action against E. coli. The results also support previous results demonstrating the utility of potential plant extracts for the synthesis of gold nanoparticles and for increasing their activity as antibacterial agents 14,18 .…”

Inhibition of Bacteria Associated with Wound Infection by Biocompatible Green Synthesized Gold Nanoparticles from South African Plant Extracts

“…It is believed that the variation in activity against the bacterial strains is dictated by the nature of the bacterial cell wall. The cell wall of the gram-positive bacterial strains, for example, has a thicker peptidoglycan layer compared to the cell wall of the gram-negative bacteria [ 63 ]. As a result, GNPs can penetrate the cell wall of the gram-negative bacteria and exert their antibacterial action more easily than in gram-positive bacteria [ 64 ].…”

Starch-templated bio-synthesis of gold nanoflowers for in vitro antimicrobial and anticancer activities

“…3a-d) while the MBC values of 0.14 mM against all the strains except E. coli, against which the MBC value was found 0.12 mM only. Literature survey reveals that there exist a number of reports describing synthesis of AuNPs by plants such as Abelmoschus esculentus (Jayaseelan et al 2013), Euphorbia hirta L. (Annamalai et al 2013), Brassica oleracea (Piruthiviraj et al 2016) that showed effective antimicrobial activity. However, a close study on the reported MIC/MBC values and/or the diameter of zone of inhibition suggests that the antimicrobial activity of our AuNFs is relatively superior compared to some of the reported values (Table 1, Sl No 1-5).…”