Synthesis of nanoparticles with interesting physico-chemical properties using efficient as well as eco-friendly technology is one of the main objectives of nanotechnology. Biological systems have been reported to synthesize inorganic materials under certain circumstances. Exploiting the biosynthetic potential of different organisms, nanoparticles of varying morphologies and sizes have been synthesized. Among the nanomaterials, gold has received considerable attention owing to its varied applications in the fields of nano-medicine, catalysis, electronics, and optics. This review gives an account on the biosynthesis of gold nanoparticles from microorganisms, plants, and other biological sources, with particular emphasis on the probable mechanisms leading to the formation of gold nanoparticles and the extent of control over nanoparticle properties that has been achieved so far in the biosynthetic protocols. It has been speculated that enzymes and/or proteins secreted by the organisms are involved in the bio-reduction and stabilization of the nanoparticles. The biosynthetic procedures could compete with existing solvent-based chemical synthetic procedures in order to achieve stable and monodisperse gold nanoparticles in large scale. Copyright © 2011 American Scientific Publishers All rights reserved.

T Panda

Department Of Chemical Engineering

BIOLOGICAL SOURCES

ECO-FRIENDLY TECHNOLOGIES

Gold Nanoparticles

Inorganic materials

Monodisperse

Physicochemical property

SOLVENT BASED

Synthetic procedures

Biochemistry

Biosynthesis

Chemical properties

Gold

Mechanisms

Microorganisms

Nanoparticles

metal nanoparticle

chemistry

Electron microscopy

methodology

review

Temperature

ultraviolet spectrophotometry

Hydrogen-Ion Concentration

Metal nanoparticles

Microscopy, Electron

Spectrophotometry, Ultraviolet

IIT Madras is a public technical and research university located in Chennai, Tamil Nadu. Founded in 1959, it is recognised as an Institute of National Importance.

IIT Madras has been ranked as the top engineering institute in India for four years in a row by the National Institutional Ranking Framework of the MHRD

It currently offers undergraduate, postgraduate and research degrees across 16 disciplines in Engineering, Sciences, Humanities and Management. About 596 faculty belonging to science and engineering departments and centres of the Institute are engaged in teaching, research and industrial consultancy.

IIT Madras

Journal of Nanoscience and Nanotechnology

Abstract: The synthesis of nanoparticles from biological sources has gained significant attention recently, however, with much emphasis on the novelty of sources. This study aims to provide a comprehensive overview on the aspects of fungal age and type of cultivation on the properties of the nanoparticles. The effect of age of Fusarium oxysporum developed in submerged culture and on solid agar medium was evaluated. When the gold salt solution was added to the fungal colony on agar medium, a deep purple colored radial zone developed in the 3 days old mycelium. The nanoparticles in the radial purple zone had two distinct characteristics when the agar blocks were dried by either lyophilization or heating in a hot air oven. The lyophilized sample contained square bi-pyramidal particles (1 to 2 μm). The oven-dried sample contained abundant truncated triangular nanoplates (150 to 500 nm), decahedrons and icosahedrons (20 to 70 nm), and a few triangular and hexagonal nanoplates (50 nm). The mycelium when suspended in 1 mM HAuCl4·3H2O presented distinct geometries of the nanoparticles in the cytoplasm and periplasm. The formation of gold nanoparticles of different morphologies within the cytoplasm, and the periplasm has implications in Surface Enhanced Raman Spectroscopic (SERS) measurements. Graphic Abstract: HRTEM images of hyphae of Fusarium oxysporum suspended in 1 mM HAuCl4·3H2O for 24 h. The nanoparticles present in the electron dense cytoplasm are markedly different from those in the periplasmic space.[Figure not available: see fulltext.]. © 2019, Springer Science+Business Media, LLC, part of Springer Nature.

Journal of Cluster Science

Biogenic Gold Nanoparticles from Fusarium oxysporum: The Impact of Fungal Morphology and Localization Studies

Synthesis of well-dispersed gold and silver nanoparticles of various size and shapes was achieved at 30°C by callus and flower extracts of Michelia champaca L. Particularly, gold nanoparticles synthesis by callus extracts was considerably more at 65°C, having a greater diversity in the geometry and size of nanoparticles. The nanoparticles were characterized by several physico-chemical techniques - UV-visible spectroscopy, TEM, EDX, FT-IR, zeta potential, and DLS measurements. The callus-generated gold and silver nanoparticles exhibit a greater diversity in size and shape than the flower extract-generated particles. Nanoparticles capped by the functional groups of the phytochemicals in the callus extract could exhibit greater stability. The synthesized AgNPs also showed competence to degrade methylene blue and exhibited anti-bacterial activity against E.coli DH5α. TLC and GCMS analysis resulted in the detection of lignans and triterpenes in the callus extract. The results have demonstrated that callus cultures of Michelia champaca can serve as novel, renewable bio-resources for controlled synthesis of biocompatible nanoparticles. Copyright © 2016 American Scientific Publishers All rights reserved.

Biosynthesis of gold and silver nanoparticles with anti-microbial activity by callus cultures of Michelia champaca L.

The addition of varying concentrations of precursor gold salt to different cellular fractions of Fusarium oxysporum, viz., the culture filtrate and the intracellular extract obtained in the growing and resting phase of the cells had a profound influence on the size, shape, and state of aggregation of the nanoparticles. Multiply-twinned nanoparticles were obtained when the culture filtrate was used for synthesizing nanoparticles while mostly irregular shapes were obtained with the intracellular extract. The time taken for the formation of gold nanoparticles in the culture filtrate of resting cells was very less (<30 min) while it took more than 8 h when the intracellular extract was used for synthesis of nanoparticles. There was a reduction in size of the nanoparticles with decreasing concentration of the gold salt from 1 mM to 0.05 mM. With the intracellular extract, the initial rate of increase in surface plasmon absorption maximum was linearly proportional to the initial concentration of the gold salt used. Gold nanoparticles were also obtained with the heat-inactivated culture filtrate which suggests alternatively the role of peptides and amino acids besides proteins in reducing and/or stabilizing the nanoparticles. Copyright © 2014 American Scientific Publishers.

Synthesis of gold nanoparticles from different cellular fractions of fusarium oxysporum

Nanoparticles have an enormous range of biomedical and environmental applications and can be used for development of various nanodevices for diagnostics and drug delivery. Biogenic production of nanoparticles, that is of silver and gold, by seed plants, especially flowering plants, has evoked considerable interest in the last decade. Different organs of plants as well as callus cultures have been used for the production of these metal nanoparticles. It is possible to regulate the geometry of the nanoparticles by modifying the experimental parameters. In many cases the phytosynthesized gold and silver nanoparticles have been demonstrated to be potentially useful for treatment of various diseases. The production of gold and silver nanoparticles by diverse species of seed plants and their biological activity are discussed in this article. © 2014 American Scientific Publishers.

Biogenic synthesis of gold and silver nanoparticles by seed plants

Gold nanoparticles of 20-100 nm diameter were synthesized within HEK-293 (human embryonic kidney), HeLa (human cervical cancer), SiHa (human cervical cancer), and SKNSH (human neuroblastoma) cells. Incubation of 1 mM tetrachloroaurate solution, prepared in phosphate buffered saline (PBS), pH 7.4, with human cells grown to ∼80% confluency yielded systematic growth of nanoparticles over a period of 96 h. The cells, stained due to nanoparticle growth, were adherent to the bottom of the wells of the tissue culture plates, with their morphology preserved, indicating that the cell membrane was intact. Transmission electron microscopy of ultrathin sections showed the presence of nanoparticles within the cytoplasm and in the nucleus, the latter being much smaller in dimension. Scanning near field microscopic images confirmed the growth of large particles within the cytoplasm. Normal cells gave UV-visible signatures of higher intensity than the cancer cells. Differences in the cellular metabolism of cancer and noncancer cells were manifested, presumably in their ability to carry out the reduction process. © 2005 American Chemical Society.

Langmuir

Growth of gold nanoparticles in human cells

Lactobacillus strains, common in buttermilk, assist the growth of gold, silver, and gold-silver alloy crystals of submicron dimensions upon exposure to the precursor ions. Several well-defined crystal morphologies are observed. Crystal growth occurs by the coalescence of clusters, and tens of crystals are found within the bacterial contour. Crystal growth does not affect the viability of the bacteria. Crystals are presumably nucleated through nanoclusters, which are formed within as well as transported into the bacteria. Biomass with the crystals can be harvested completely. Results point to potential applications in analytical chemistry, nanotechnology, medicine, and metal ion recovery. Coalescence appears to be a route by which surface area of the crystal is reduced so that it can be effectively protected to avoid biological damage.

Crystal Growth and Design

Coalescence of Nanoclusters and Formation of Submicron Crystallites Assisted by Lactobacillus Strains

Journal	Journal of Nanoscience and Nanotechnology
ISSN	15334880
Open Access	No