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

Mainly extracellular

Silver nanoparticle

Gold nanoparticle

Cadmium

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

Literature for biological system involved in nanoparticle synthesis

Nano is truly in

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