An overview of the plant-mediated green synthesis of noble metal nanoparticles for antibacterial applications

Metallic nanoparticles (MNPs) with attractive physicochemical properties are utilized in several biomedical domains, such as antimicrobial agents. Many researchers have tried to explore novel aspects of the respective worth of MNPs, arising from their small size. The increasing demand for MNPs has attracted research interest on developing simple, rapid, inexpensive, and environmentally friendly processes for the synthesis of MNPs. Among the developed types of MNPs, noble metal nanoparticles (NMNPs), especially silver (Ag), gold (Au), and platinum (Pt), have received much attention, due to their excellent properties and diverse applications. For example, microbial contaminations are one of the most severe issues faced in food industries, medical device application, and water treatment. To address these issues, nanoscale materials and nanostructures, especially NMNPs, have been developed, offering novel antimicrobial features. Herein, we review the available green approaches for producing NMNPs (AgNPs, AuNPs, and PtNPs) using different plant extracts, and discuss the antibacterial influences and biocompatibility of these NPs. We highlight the developments of NMNPs for resolving existing toxicity concerns, their antimicrobial effects, as well as the future challenges in this field. (C) 2020 The Korean Society of Industrial and Engineering Chemistry. Published by Elsevier B.V. All rights reserved.