Review Article
Biological synthesis of metallic nanoparticles

https://doi.org/10.1016/j.nano.2009.07.002Get rights and content

Abstract

The synthesis of metallic nanoparticles is an active area of academic and, more importantly, “application research” in nanotechnology. A variety of chemical and physical procedures could be used for synthesis of metallic nanoparticles. However, these methods are fraught with many problems including use of toxic solvents, generation of hazardous by-products, and high energy consumption. Accordingly, there is an essential need to develop environmentally benign procedures for synthesis of metallic nanoparticles. A promising approach to achieve this objective is to exploit the array of biological resources in nature. Indeed, over the past several years, plants, algae, fungi, bacteria, and viruses have been used for production of low-cost, energy-efficient, and nontoxic metallic nanoparticles. In this review, we provide an overview of various reports of synthesis of metallic nanoparticles by biological means.

From the Clinical Editor

This review provides an overview of various methods of synthesis of metallic nanoparticles by biological means. Many chemical and physical procedures used for synthesis of metallic nanoparticles are fraught with major problems: toxic solvents, hazardous by-products, high energy consumption. Over the past several years, plants, algae, fungi, bacteria, and viruses have been used for production of low-cost, energy-efficient, and nontoxic metallic nanoparticles.

Section snippets

Bacteria in nanoparticle synthesis

Among the milieu of natural resources, prokaryotic bacteria have been most extensively researched for synthesis of metallic nanoparticles. One of the reasons for “bacterial preference” for nanoparticles synthesis is their relative ease of manipulation. In one of the earliest studies in this technology, Slawson et al found that a silver-resistant bacterial strain isolated from silver mines, Pseudomonas stutzeri AG259, accumulated AgNPs within the periplasmic space. Of note, the particle size

Yeast in nanoparticle synthesis

Few, if any, reports exist about yeast-mediated synthesis of metallic nanoparticles. In an isolated report, Kowshik et al have demonstrated that MKY3, a silver-tolerant yeast species, when challenged with soluble silver in the log phase of growth, could precipitate a majority (>99%) of silver extracellularly as elemental nanoparticles. The size of synthesized AgNPs ranged from 2 to 5 nm. Notably, the authors used a novel procedure, based on differential thawing of the sample, for separation of

Fungi in nanoparticle synthesis

Because of their tolerance and metal bioaccumulation ability, fungi are taking the center stage of studies on biological generation of metallic nanoparticles.22 A distinct advantage of using fungi in nanoparticle synthesis is the ease in their scale-up (eg, using a thin solid substrate fermentation method). Given that fungi are extremely efficient secretors of extracellular enzymes, it is thus possible to easily obtain large-scale production of enzymes. Further advantages of using a

Plants in nanoparticle synthesis

Whereas microorganisms such as bacteria, actinomycetes, yeasts, and fungi continue to be researched and investigated in synthesis of metallic nanoparticles, the use of parts of whole plants for similar nanoparticle biosynthesis methodologies is an exciting possibility that is relatively unexplored and underexploited.26

Extracellular synthesis of AgNPs by reduction of aqueous Ag+ ions by the extract of geranium leaves (Pelargonium graveolens) has been reported.27 In comparison with the earlier

Algae in nanoparticle synthesis

Similar to yeast, there are few, if any, reports of algae being used as a “biofactory” for synthesis of metallic nanoparticles. Recently, Singaravelu et al adopted a systematic approach to study the synthesis of metallic nanoparticles by Sargassum wightii.30 This is the first report in which a marine alga has been used to synthesize highly stable extracellular gold nanoparticles in a relatively short time period compared with that of other biological procedures. Indeed, 95% of the bioreduction

Viruses in nanoparticle synthesis

Biological approaches to nanocrystal synthesis have been extended to intact biological particles. Viral scaffolds can template the nucleation and assembly of inorganic materials. Indeed, cowpea chlorotic mottle virus and cowpea mosaic virus have been used as nucleation cages for the mineralization of inorganic materials.31, 32 Furthermore, tobacco mosaic virus has been shown to direct successfully the mineralization of lead sulfide (PbS) and CdS crystalline nanowires.33 Taking the idea one step

Conclusions

A critical need in the field of nanotechnology is the development of a reliable and ecofriendly process for synthesis of metallic nanoparticles. To accomplish this, the use of natural sources like biological systems becomes essential. The synthesis of inorganic materials by biological systems is characterized by processes that occur close to ambient temperature and pressures and also at neutral pH. Of the various biological systems, bacteria are relatively easy to manipulate genetically,

Acknowledgments

We would like to thank Dr. Yogesh Shouche, Dr. Sham Diwanay, and Vasudeo Kshirsagar for their suggestions and guidance. We are grateful to Dr. Leonard D. Kohn (Ohio University, Athens, Ohio) and Dr. Nilesh M. Dagia (Piramal Life Sciences Limited, Mumbai, India) for editorial assistance with the manuscript. We also wish to thank colleagues at the National Center for Cell Science (Pune, India) and Abasaheb Garware College (Pune, India) for their constant support and encouragement.

References (43)

  • ChenJ.C. et al.

    Evidence of the production of silver nanoparticles via pretreatment of Phoma sp.3.2883 with silver nitrate

    Lett Appl Microbiol

    (2003)
  • TanY. et al.

    Preparation of gold, platinum, palladium and silver nanoparticles by the reduction of their salts with a weak reductant–potassium bitartrate

    J Mater Chem

    (2003)
  • MallickK. et al.

    Polymer stabilized silver nanoparticles: a photochemical synthesis route

    J Mater Sci

    (2004)
  • SlawsonR.M. et al.

    Germanium and silver resistance, accumulation and toxicity in microorganisms

    Plasmid

    (1992)
  • KlausT. et al.

    Silver-based crystalline nanoparticles, microbially fabricated

    Proc Natl Acad Sci U S A

    (1999)
  • ParikhR.P. et al.

    Extracellular synthesis of crystalline silver nanoparticles and molecular evidence of silver resistance from Morganella sp.: towards understanding biochemical synthesis mechanism

    Chembiochem

    (2008)
  • NairB. et al.

    Coalescence of nanoclusters and formation of submicron crystallites assisted by Lactobacillus strains

    Cryst Growth Des

    (2002)
  • LengkeM. et al.

    Biosynthesis of silver nanoparticles by filamentous cyanobacteria from a silver(I) nitrate complex

    Langmuir

    (2006)
  • CunninghamD.P. et al.

    Precipitation of cadmium by Clostridium thermoaceticum

    Appl Environ Microbiol

    (1993)
  • BhardeA. et al.

    Bacterial aerobic synthesis of nanocrystalline magnetite

    JACS

    (2005)
  • KonishiY. et al.

    Microbial synthesis of gold nanoparticles by metal reducing bacterium

    Trans Mater Res Soc Jpn

    (2004)
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    No conflict of interest was reported by the authors of this paper.

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