Green synthesis of metal nanoparticles using plants

Synthesis of silver nanoparticles using Acalypha indica leaf extracts and its antibacterial activity against water borne pathogens.

In materials science, “green” synthesis has gained extensive attention as a reliable, sustainable, and eco-friendly protocol for synthesizing a wide range of materials/nanomaterials including
 metal/metal oxides nanomaterials, hybrid materials, and bioinspired materials. As such, green synthesis is regarded as an important tool to reduce the destructive effects associated with the traditional methods of synthesis for nanoparticles commonly utilized in laboratory and industry. In this review, we summarized the fundamental processes and mechanisms of “green” synthesis approaches, especially for metal and metal oxide [e.g., gold (Au), silver (Ag), copper oxide (CuO), and zinc oxide (ZnO)] nanoparticles using natural extracts. Importantly, we explored the role of biological components, essential phytochemicals (e.g., flavonoids, alkaloids, terpenoids, amides, and aldehydes) as reducing agents and solvent systems. The stability/toxicity of nanoparticles and the associated surface engineering techniques for achieving biocompatibility are also discussed. Finally, we covered applications of such synthesized products to environmental remediation in terms of antimicrobial activity, catalytic activity, removal of pollutants dyes, and heavy metal ion sensing.

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‘Green’ synthesis of metals and their oxide nanoparticles: applications for environmental remediation

Plant extract mediated synthesis of silver and gold nanoparticles and its antibacterial activity against clinically isolated pathogens.

Synthesis of antimicrobial silver nanoparticles by callus and leaf extracts from saltmarsh plant, Sesuvium portulacastrum L.

This is the first report of synthesis of silver nanoparticles by using callus extract of Carica papaya. MS medium supplemented with the growth hormones, 2.0 mg l−1 IBA and 0.5 mg l−1 BAP was found to be more suitable for the induction of callus and multiple shoots in papaya. The extract of callus obtained by grinding showed ability of synthesis of silver nanoparticles when treated with silver nitrate (1 mM). The formation of brown colour in the reaction mixture indicates the synthesis of silver nanoparticles. The further detection and characterization of these synthesized silver nanoparticles was carried by spectrophotometry. FTIR spectrum analysis showed peaks between 1000–2000 cm−1 which confirmed the presence of proteins and other ligands required for the synthesis and stabilization of silver nanoparticles. SEM micrograph confirmed the synthesis of spherical silver nanoparticles in the size range of 60–80 nm.

Namrata Mude

Papers

Synthesis of silver nanoparticles using callus extract of Carica papaya - a first report.