Biogenic Synthesis of Silver Nanoparticles and Their Applications

Abstract

One of the most important criteria of nanotechnology is the development of clean, nontoxic, and environmentally acceptable ‘‘green chemistry’’ procedures, involving organisms ranging from bacteria to fungi. The interactions between microbes and metals have been well documented and the ability of microorganisms to extract and accumulate metals is already employed in biotechnological processes such as bioleaching and bioremediation. The synthesis of chemical, photoelectrochemical, and electronic properties enables the synthesis of nanoparticles of different chemical compositions, well-defined sizes, and distinct morphologies. It is well known that many organisms can synthesize inorganic materials either intra- or extracellularly. The biological synthesis of nanoparticles is easy, efficient, and eco-friendly in comparison to chemical or physical synthesis. Physical and chemical synthesis procedures involve toxic solvents as well as high pressure, energy, and temperature, so in biological synthesis the best option is the synthesis of nanoparticles using microbes. The use of fungi in the synthesis of nanoparticles is a relatively recent addition to the list of microorganisms possessing nanoparticle biosynthesis “ability”. The application of fungi to produce nanoparticles is potentially exciting because of their ability to secrete large amounts of enzymes. In comparison with other microbial syntheses, the fungal synthesis of silver nanoparticles (AgNPs) is very easy to handle at laboratory scale and fungi do contain larger proteins in their cell walls. Moreover, it is easy to harvest the mycelia. Nanomedicine is a burgeoning field of research with tremendous prospects for the improvement of the diagnosis and treatment of human diseases. Research is carried out in manipulating microorganisms at the genomic and proteomic levels. With the recent progress and the ongoing efforts in improving particle synthesis efficiency and exploring their biomedical applications, we are hopeful that the implementation of these approaches on a large scale and their commercial applications in medicine and healthcare will take place in the coming years.