By Vaibhav Kumar Maurya
Topic of the day
Introduction
definition
Approaches used
Nano scale structure synthesis methods
Biological system for nanoparticles
Characterization
Applications
Nano & technology
The understanding and control of matter at dimensions of
roughly 1 to 100 nanometres.
Richard Feynman introduce as an idea in 1954
Norio Taniguchi coined the name “nanotechnology” in 1974
What is Nanotechnology?
Nanotechnology is the art an science of manipulating
matter at the nanoscale
Allows the placement of small structures placed with
precision, simplicity and low cost
An
gst
rom
Na
no
met
erM
icro
met
erM
illi
mete
r
Top down
Bottom up
Bulk material
Thin material
Heterostructures
nanostructure
nanostructure
Protein
Molecule
atom
Approaches for nanoscale structure
Various nano-synthesis methods
Chemical•Sol-gel Processing
•Solution-based synthesis
Physical •Ball Milling
•Thermal evaporation
•Lithography
•Vapour Phase
Biological•In bacteria
•In fungi
•Yeast
•Using plant extracts
Radiolarians Sponge Spicule Diatoms Rice leaf blade
Biology: The inspiration for nanomaterials synthesis
Biological synthesis
Rapid synthesis, controlled toxicity, controlling on size characteristics, economical and eco-friendly approach
Crucial point before going for biological method
What biological system can be used to (bacteria, plant and fungi) synthesis nanostructure ?
Can we do it extracellularly ?
What is the biochemical process leading to nanoparticle formation ?
Is size control possible ? Better monodispersity ?
How about nanoparticle shape modulation ?
Can we use extracts of plants in nanobiosynthesis ?
Fungi and Yeast
•Extra cellular
•Intera cellular
• Cell wall
surface
Bacteria
•Extracellular
•Intracellular
Plant & Plant extract
Extracellular
Inexpensive reduction
Silver
Gold
Gold
Cds
Gold
Iron
Biological system for nanoparticles
Why do organisms synthesize nanoparticles?
Major reasons involved in such synthesis is detoxification which can be carried out by
1. Modifications in the cellular transport mechanisms to restrict entry of the toxicions into the cell
2. Sequestration of the toxic species within the cell (intracellular sequestration) oroutside the cell (extracellular sequestration)
3. Activation of energy-dependent efflux pathways to eliminate the toxic species
4. Enzyme catalyzed oxidation or reduction of the toxic species to a less toxic form
Mechanism involved in biogenic nanoparticles synthesis
PeptidesProteins
Polyols
Heterocyclic compounds
Stabilizing agent
Bacterial biosynthesis Iron nanoparticles
1. Magnetite nanoparticles
2. Greigite nanoparticles
Organism- Actinobacter spp
Bacterial culture in Luria Broth
Aqueous sol.of
K3 Fe(CN)6+K4 Fe(CN)6
In 2:1 millimolar ratio kept for a
period of week
Product identification
Au-Ag alloys: Synthesis Fungus Fusarium oxysporum.
It has been found that initially Au is reduced followed by Ag leading to nanoparticles of Au-Ag alloy.
Depending on the biomass of fungus used one can change the composition of the alloy nanoparticleformed from pure Au to pure Ag with increase in the biomass concentration
Process involved in nanoparticle synthesis by fungi
Screening of fungi
F. Oxysporum and Verticilium sp.
Culturing and Biomass harvesting
Biomass inoculation in precursors
Filtrate characterization for
Oxides formation
SiO2
TiO2
ZrO2
Fe3O4
BaTiO3
Potential fungal and Yeast
Extracellular nano particle synthesis
Fungus - mediated bioleaching approach towards synthesis of
oxide nanoparticles using natural agro-industrial wastes
Provides single step biosynthesis process
Protocols involving free from toxicants and natural capping agents
Can generate bimetallic silver and gold shell nanoparticles
Excellent stability and size control cost-effective large-scale production of metallic,
semiconductor and metal oxide nanoparticles
Process involved in nanoparticles synthesis by plant extract