4. Nanoparticles are particles which lie in dimensions between 1-100 nm.
Nano derived from the Greek word Nanos which means dwarf or
extremely small
For example, nanoseconds (billionth of a second), nanometer (billionth of a
meter), nanoliter (billionth of a liter).
NANOPARTICLES
4/20/2020 4
6. o Clean and eco-friendly approach, as toxic chemicals are not used.
o The active biological component itself act as capping and reducing
agent, therefore reduction the overall cost of synthesis process.
o Can be used at large scale of nanoparticles.
o External experimental conditions like high energy and high pressure
are not required, leads to energy saving process
4/20/2020 6
7. 4/20/2020 7
BIOLOGICAL
METHOD
Or
GREEN METHOD
CHEMICAL
METHOD
PHYSICAL
METHOD
• Time and energy
consuming, synthesis
at high temperature,
and pressure
Simple, inexpensive,
and low temperature,
use of toxic reducing
and stabilizing agents
make it harmful.
Easy, efficient and eco-
friendly. eliminates the use of
toxic chemicals, consume less
energy and produce safer
products and by products
8. 4/20/2020 8
Microorganisms
Plants
Microbial synthesis is of
course readily scalable,
environmentally benign and
compatible with the use of the
product for medical
applications, but production
of microorganisms is often
more expensive than the
production of plant extracts
10. 4/20/2020 10
10 ml of 0.002 M aq. chloroauric acid H[AuCl4]
Stir for 15 minutes at 800 C
Add 10 ml of 0.01 M aq. Sodium Citrate
Stir for 30 minutes at 800 C
Clear Solution turns to red indicating formation of Gold nanoparticles
11. 4/20/2020 11
OH-CH2-CH2-OH → CH3-CHO + H2O
6(CH3-CHO) + 2HAuCl4 → 3(CH3-CO-CO-CH3) + 2Au0 + 8HCl
oxidation of the ethylene glycol reducing the metallic
precursor to its zero-valence state.
13. 4/20/2020 13
Characterization
TEM (Transmission Electron Microscopy)
SEM (Scanning Electron Microscopy)
Gel Electrophoresis
UV-Visible spectroscopy
Dynamic Light Scattering (DLS)
14. 4/20/2020 14
TEM (Transmission Electron Microscopy:-
Transmission electron microscopy is
one of the most frequently used
tools for the atomic-scale
characterization of atomic and
electronic structures of
semiconductor materials
16. 4/20/2020 16
SEM (Scanning Electron Microscopy)
The SEM is routinely used to generate high-resolution
images of shapes of objects electron-sample interactions and
to show spatial variations in chemical compositions:-
1) acquiring elemental maps or spot chemical analyses
using Energy-Dispersive X-Ray Spectroscopy.
2)discrimination of phases based on mean atomic number
(commonly related to relative density) using backscattered
electrons.
3) compositional maps based on differences in trace element
"activators" (typically transition metal and Rare Earth
elements) using (cathodoluminescence.
18. 4/20/2020 18
• Separate gold nanoparticles based on
size, shape, and charge.
Gel Electrophoresis
• The attachment of DNA to Au
nanoparticles can be clearly observed
by gel electrophoresis
GE depends on two factors:
1) size
2) charge
• The bigger the size, the
slower migrate
• The higher charge, the faster
particles will migrate
• Gel electrophoresis (GE) is a widely used
and inexpensive separation technique that
can be adapted for the characterization of
nanoparticle-bio-molecular conjugates.
20. 4/20/2020 20
UV-Visible spectroscopy
Biosynthesized AuNPs were characterized by UV-Visible spectrophotometer for the
confirmation of complete bio reduction of Gold ions to Gold nanoparticles in aqueous
plant extract
21. 4/20/2020 21
UV-visible spectra were recorded from 300 -800 nm wavelengths at 2 nm interval.
UV-Spectroscopy image of colloidal gold
22. 4/20/2020 22
• Determine sizes of metallic nanoparticles or quantum dots
• Assess colloidal stability as a precursor to aggregation and precipitation.
• Gold nanoparticles (GNPs) are extraordinary light scatterers at or near their surface plasmon
resonance wavelength.
• The DLS can be used as a very convenient and powerful tool for gold nanoparticle
bioconjugation and biomolecular binding studies.
Dynamic Light Scattering (DLS)
