Greener Techniques for the Synthesis of Silver Nanoparticles Using Plant Extracts, Enzymes, Bacteria, Biodegradable Polymers, and Microwaves

Abstract

The use of silver nanoparticles (AgNPs) is gaining in popularity due to silver's antibacterial properties. Conventional methods for AgNP synthesis require dangerous chemicals and large quantities of energy (heat) and can result in formation of hazardous byproducts. This article summarizes recent activity in this general area where environmentally friendly synthetic techniques are currently being explored for the synthesis of "greener" AgNPs including the use of plant extracts, biodegradable polymers, and enzymes/bacteria and alternative energy input systems, such as microwave irradiation. Microwave heating enables efficient formation of nanostructures of uniform small sizes in shorter reaction times with reduced energy consumption; preventing agglomeration of ensuing nanoparticles is an additional attribute.

Photosynthesis vs. Traditional Chemical Synthesis for Obtaining Biocompatible Drug Delivery (Dds) Nanoparticles: A Review.

“…Furthermore, problems associated with complex treatments in case of microbial synthesis, including microbial isolation, culturing, and maintenance are resolved in the case of phytosynthesis. Another advantage for the phytosynthesis is the controlled flexibility in terms of size and morphology due to the diverse types of plants that can be used [1,8,9].…”

“…Such phytochemicals posses' redox capacity which makes them act as reducing agents. In addition, other phytochemical can act as stabilizers (capping agents) during nanoparticles synthesis [9,10].…”

“…In the fourth stage, reducing metabolites, and large number of biomolecules which act as stabilizers, lead to an isotropic growth of NPs, forming spherical NPs. Finally, with an increase in aging time, large-sized silver nanoparticles are formed and the crystalline phase changed from polycrystalline to single crystalline through Ostwald ripening [9,11,12].…”

Green Synthesis: Nanoparticles and Nanofibres Based on Tree Gums for Environmental Applications

“…glutathione), and sugars (e.g. glucose, fructose) are such materials, which provide suitable reducing and surface agents for the nanoparticle synthesis/stabilization [14][15][16][17][22][23][24][25][26][27][28][29][30]. Plant extracts are regarded as one of the most promising natural reducing agents, such as metabolities (e.g.…”

“…Green chemistry is a set of principles or practises that encourages the design of products and processes that reduce or eliminate the use and generation of hazardous substances [11][12][13][14]. Current green nanotechnology practices often involve the use of natural sources, non-hazardous solvents, biodegradable and biocompatible materials and energy-efficient processes in the preparation of nanoparticles [15][16][17].…”