Biogenic synthesis of gold and silver nanoparticles used in environmental applications: A review

Due to their physical, chemical, optical, and mechanical properties, metallic nanoparticles (MNPs) are increasingly being used, with an emphasis on silver nanoparticles (AgNPs) and gold nanoparticles (AuNPs). In recent years, green synthesis has gained prominence for exploring the use of naturally available biological sources for the obtention of metallic nanoparticles. Among these, algae and plants stand out due to the presence of polysaccharides, proteins, polyphenols, and vitamins (among others) in their composition, which can act in the reduction and stabilisation of MNPs, and these biogenic materials have been characterised mainly by spectrometric and microscopic techniques. In addition, due to the numerous advantages of nanoparticles (NPs) synthetize from biogenic source, such as their simplicity and cost benefits, they have been used in the development of sensors applied in the determination of contaminants present in environmental samples and in the catalytic reduction of organic and inorganic contaminants. Therefore, this review describes the synthesis, mechanisms, characterization, and environmental analytical applications of NPs obtained by biogenic synthesis as well as the perspectives and challenges of these NPs. (c) 2021 Elsevier B.V. All rights reserved.

Automated summary

Metallic nanoparticles, especially silver and gold nanoparticles, are increasingly used due to their physical properties, with a focus on green synthesis using biological sources. Algae and plants are highlighted for their composition of beneficial components that play a role in the reduction and stabilization of nanoparticles, characterized by spectroscopic and microscopic techniques. These biogenically synthesized nanoparticles are simple and cost-effective, widely applied in environmental contaminant detection and catalytic reduction of contaminants.