Nanobiotechnology lecture 1-3

1. Fundamentals of
Nano-biotechnology
Course Number: UBE07E02
Introduction
Tridib Kumar Bhowmick
Dept. of Bioengineering
tbhowmick.be@nita.ac.in

2. 2
The nanoscale
• ‘Nano’ is the unit prefix representing 10–9.
Some common unit prefixes

3. Why Nanoscale?

4. 4
• Carbon can exist in two forms in daily life:
– Diamond (tetrahedral)
– Graphite (hexagonal)
Diamond Graphite

5. 5
• Carbon atoms can also be arranged in many other ways to
produce other forms, e.g.
– Carbon nanotube (roll up layer of carbon atoms from graphite)
– Fullerene (C-60: 20 hexagons + 12 pentagons)
Carbon nanotube
R ~ few nm
C-60 (a special kind of fullerene)
Others: C-70, C-76, C-84, etc
R ~ 1 nm

6. 6
• exhibits different behaviour than the bulk form.
Physical properties of nanomaterials
• much stronger and
stiffer than their bulk
forms.
• both strong and
ductile.
Badminton racquets made of fibres
mixed with carbon nanotubes
Mechanical properties

7. 7
Strange optical properties appear in nanomaterials.
e,g 1
gold
Gold coin (bulk form) Aqueous colloidal gold
Particle:10 – 100 nm
Brilliant red in color
Optical properties
e.g.2
Zinc oxide & titanium oxide in nanoscale can block UV that they can
be user in sunscreen and cosmetics

8. 8
• Most nanomaterials have a lower melting point
than their bulk forms.
Variation of the melting point of gold
nanoparticles with size
Thermal properties

9. 9
A CPU heat sink
• The thermal conductivity of a material depends on its
form (e.g. diamond is a good thermal conductor but
nanotubes are 2 times better than diamond).
A heat sink with carbon nanotubes

10. 10
• Some insulators become conductors in their nano forms.
e.g. SiO2
• The resistivity of metals (normally small) greatly
increases when the metal sample is reduced to nanosize.
Electrical properties
Magnetic properties
Hard disk drives record data using
ferromagnetic materials.
Most ferromagnetic
materials (can keep
magnetization) become
paramagnetic (cannot keep
magnetization) when they
are reduced to nano size.

11. 11
Recent development in nanotechnology
The technology used in CPUs nowadays
reaches the nanoscale.
Electronics and computer hardware

12. 12
A CRT display
An FED display
(Field emission display)
(Efficient
electron emitter)
FED :
1.Reduce thickness
2.Use less power

13. 13
Material science
Badminton racquets made of fibres
mixed with carbon nanotubes
New bullet-proof vest produced
with carbon nanotubes

14. 14
Nanomedicine
A nanorobot performing a surgery on a cell
1.Some nanomaterials have specific interactions with special cells
2.target on defective cells/ deliver appropriate treatment
3.nanodoctors: repair cells & defective DNA

15. 15
Energy
A solar cell made of nanocrystals of titanium dioxide:
To facilitate conversion of solar energy to electrical
energy

16. 16
little knowledge about the potential hazards of nanotechnology.
Nanoparticles are chemically very reactive :
1. toxic,
2. highly penetrating (even reach DNA and cause DNA mutation),
3. easily absorbed by plants/animals/human body/water sources/food
Potential hazards of nanotechnology

17. Unique Characteristics of
Nanoparticles
• Large surface to volume ratio
• High percentage of atoms/molecules on the surface
• Surface forces are very important, while bulk forces
are not as important.
• Metal nanoparticles have unique light scattering
properties and exhibit plasmon resonance.
• Semiconductor nanoparticles may exhibit confined
energy states in their electronic band structure (e.g.,
quantum dots)
• Can have unique chemical and physical properties
• Same size scale as many biological structures

18. The properties of Nano Materials are very much different
from those at a larger scale.
Two principal factors cause the properties of Nano
Materials to differ significantly from other materials.
1.Increased relative surface area.
2.Quantum confinement effect.
These factors can charge or enhance properties such as
reactivity, strength and electrical characteristics.
Why properties of Nano Materials are different ?

19. Examples of Unusual Properties
• Lowered phase transition temps
• Increased mechanical strength
• Different optical properties
• Altered electrical conductivity
• Magnetic properties
• Self-purification and self-perfection

20. • Physical properties of nanoparticles are dependent
on:
– Size
– Shape (spheres, rods, platelets, etc.)
– Composition
– Crystal Structure (FCC, BCC, etc.)
– Surface ligands or capping agents
– The medium in which they are dispersed
Physical Properties of Nanoparticles

21. Size
• Molecules, nanoparticles,
and bulk materials can be
distinguished by the number
of atoms comprising each
type of material.
• Note: these are very
approximate numbers!
Poole, C., Owens, F. Introduction to Nanotechnology. Wiley, New Jersey. 2003
1
10
102
103
104
105
106
Molecules
Nanoparticles
Bulk
# of atoms

22. Size
• Nanoparticles exhibit unique properties due to
their high surface area to volume ratio.
• A spherical particle has a diameter (D) of 100nm.
– Calculate the volume (V) and surface area (SA)
3
22
3
9
3
3
m
10
x
24
.
5
V
6
)
10
100
(
V
6
D
r
3
4
V
-
-
=
×
π
=
π
=
π
=
Poole, C., Owens, F. Introduction to Nanotechnology. Wiley, New Jersey. 2003
2
14
2
9
2
2
m
10
141
.
3
SA
)
10
100
(
SA
D
r
4
SA
-
-
×
=
×
π
=
π
=
π
=

23. Surface Area:Volume Ratio
• This gives an approximate surface area to volume
ratio of >107:1 which is significantly larger than a
macro sized particle.
• As the surface area to volume ratio increases so
does the percentage of atoms at the surface and
surface forces become more dominant.
• Generally accepted material properties are derived
from the bulk, where the percentage of atoms at
the surface is miniscule. These properties change
at the nanoscale.

24. Size
Nanoparticle Nanoparticle Volume Surface Area SA:Vol Ratio
Diameter (nm) Diameter (um) (nm3) (nm2) (nm2/nm3)
1 0.001 0.524 3.14 6
10 0.01 524 314 0.6
100 0.1 523598 31416 0.06
1000 1 5.24E+08 3.14E+06 0.006
10000 10 5.24E+11 3.14E+08 0.0006
100000 100 5.24E+14 3.14E+10 0.00006
1000000 1000 5.24E+17 3.14E+12 0.000006
Some example calculations for volume and surface area of nanoparticles.
These calculations use nm as unit of length.

25. Surface Area:Volume Ratio
In this graph:
SA = nm2
Vol = nm3
SA:Vol Ratio = nm2/nm3
The ratio increases
dramatically when the
nanoparticle diameter drops
below about 100 nm

26. Increase in a Surface Area to Volume ratio
Nano Materials have a relatively larger Surface area when
compared to the same volume or mass of the material
produced in a larger form.
Let us consider a Sphere of radius “r”.
Its Surface Area =4πr2.
Its volume= 4/3πr3
Surface Area to Volume Ratio= 3/r.
Thus when the radius of the Sphere decreases , its Surface
to Volume ratio increases.

27. 2
2
6
1
6 m
m
area
surface 


m
1

28.  Let us consider one Cubic Volume shown in figure its the
Surface Area is 6m2 .
 When it is divided into eight pieces its Surface Area
becomes 12m2, similarly When the same volume is divided
into 27 pieces its Surface Area becomes 18m2.
 Thus we find that when the given volume is divided into
smaller pieces the Surface Area increases.
 Hence as particle size decreases a greater proportion of
atoms are found at the surface compared to those inside.
 Nano particles have a much greater surface area per given
volume compared with larger particles. It makes materials
more Chemically reactive.

29. 2
2
12
8
)
2
1
(
6 m
m
area
surface 



m
2
1

30. Size
• As the percentage of atoms at the surface increases, the
mechanical, optical, electrical, chemical, and magnetic
properties change.
– For example optical properties (color) of gold and silver change,
when the spatial dimensions are reduced and the concentration is
changed.

31. Size
Melting point as a function of particle size
• Nanoparticles have a lower melting point than their
bulk counterparts
Melting point of gold nanoparticles as a
function of size.
Source: Ph. Buffat and J-P. Borel, Phys. Rev. A 13,
2287–2298 (1976)

32. Nano Materials have properties that are different
from those of bulk materials.
Most Nano structure materials are Crystalline in
nature and they posses unique properties.
Properties of Nano Materials

33. Physical Properties of Nano Particles
• Crystal structure of Nano particles is same as bulk
structure with different lattice parameters.
• The inter atomic spacing decreases with size and
this is due to long range electrostatic forces and the
short range core-core repulsion.
• The Melting point of Nanoparticles decreases with
size.

34. The Electronic structure of Nanoparticles is
dependent on its size and the ability of Nano
cluster to react, depends on cluster size.
• The large Surface area to volume ratio the
variations in geometry and the electronic structure
of Nano particles have a strong effect on catalytic
properties.
Chemical Properties

35. The electronic structure of Nano materials is
different from its bulk material.
• The density of the energy states in the conduction
band changes.
• When the energy spacing between two energy
levels is more than KBT , energy gap is created.
• Nano clusters of different sizes will have different
electronic structures and different energy level
separations.
• The Ionization potential at Nano sizes are higher
than that for the bulk materials
Electrical properties

36. • The Magnetic Moment of Nano particles is
found to be very less when compared them with
its bulk size.
• Nanoparticles made of semiconducting
materials Germanium , Silicon and Cadmium
are not Semiconductors.
Magnetic Properties

37. Applications of Nanomaterials
Chemical Industry:
• Fillers for point systems
• Coating Systems based
on Nano composites.
• Magnetic fluids.
Automotive Industry:
• Light weight
construction
• Painting
• Catalysts
• Sensors

38. Medicine
• Drug delivery systems
• Active agents
• Medical rapid tests
• Antimicrobial agents
and coatings.
• Agents in cancer
therapy.
Electronic Industry:
• Data memory
• Displays
• Laser diodes
• Glass fibers
• Filters
• Conductive, antistatic
coatings.

39. Energy Sources
• Fuel cells
• Solar cells
• Batteries
• capacitors.
Cosmetics
• Sun protection creams
• Tooth paste

40. example
Category of nanomaterials
layers, multi-layers, thin films,
platelets and surface coatings. They
have been developed and used for
decades, particularly in the
electronics industry.
One-dimensional nanomaterials
nanowires, nanofibres made from a
variety of elements other than
carbon, nanotubes and, a subset of
this group, carbon nanotubes.
Two-dimensional nanomaterials
are known as nanoparticles and
include precipitates, colloids and
quantum dots (tiny particles of
semiconductor materials), and
Nanocrystalline materials
Three-dimensional nanomaterials
Nanomaterials’ Characteristics

41. • Examples
- Carbon Nanotubes
- Proteins, DNA
- Single electron transistors
AFM Image of DNA
Carbon Nanotubes

42. substrate
Semiconductor
growth (single
layer)

44. Applications of Nano Materials

45. • Because of their small size, nanoscale devices can readily
interact with biomolecules on both the surface of cells and
inside of cells.
• By gaining access to so many areas of the body, they have the
potential to detect disease and the deliver treatment.
1. Nanotechnology Applications in Medicine
• Nanoparticles can can deliver drugs directly to
diseased cells in your body.
• Nanomedicine is the medical use of molecular-
sized particles to deliver drugs, heat, light or
other substances to specific cells in the human
body.

46. • Quantum dot- that identify the location of cancer
cells in the body.
• Nano Particles - that deliver chemotherapy drugs
directly to cancer cells to minimize damage to healthy
cells.
• Nanoshells - that concentrate the heat from infrared
light to destroy cancer cells with minimal damage to
surrounding healthy cells.
• Nanotubes- used in broken bones to provide a
structure for new bone material to grow.

47. Nano shells as Cancer Therapy
Nano shells are injected into cancer area and they recognize
cancer cells. Then by applying near-infrared light, the heat
generated by the light-absorbing Nano shells has successfully
killed tumor cells while leaving neighboring cells intact.

50. • In this diagram (next page), Nano sized sensing wires are laid
down across a micro fluidic channel. As particles flow through the
micro fluidic channel, the Nanowire sensors pick up the molecular
identifications of these particles and can immediately relay this
information through a connection of electrodes to the outside
world.
• These Nanodevices are man-made constructs made with carbon,
silicon Nanowire.
• They can detect the presence of altered genes associated with
cancer and may help researchers pinpoint the exact location of
those changes
Nanowires – used as medical sensor

52. Past
Shared computing thousands of
people sharing a mainframe computer
Present
Personal computing
Future
Ubiquitous computing thousands of computers sharing each
and everyone of us; computers embedded in walls, chairs, clothing,
light switches, cars….; characterized by the connection of things in
the world with computation.
2. Nano Computing Technology

53. 3. Sunscreens and Cosmetics
• Nanosized titanium dioxide and zinc oxide are currently used in
some sunscreens, as they absorb and reflect ultraviolet (UV) rays.
• Nanosized iron oxide is present in some lipsticks as a pigment.
4. Fuel Cells
The potential use of nano-engineered membranes to intensify
catalytic processes could enable higher-efficiency, small-scale fuel
cells.
5. Displays
• Nanocrystalline zinc selenide, zinc sulphide, cadmium sulphide and
lead telluride are candidates for the next generation of light-emitting
phosphors.
• CNTs are being investigated for low voltage field-emission displays;
their strength, sharpness, conductivity and inertness make them
potentially very efficient and long-lasting emitters.

54. 6. Batteries
• With the growth in portable electronic equipment (mobile phones,
navigation devices, laptop computers, remote sensors), there is great
demand for lightweight, high-energy density batteries.
• Nanocrystalline materials are candidates for separator plates in
batteries because of their foam-like (aerogel) structure, which can
hold considerably more energy than conventional ones.
• Nickel–metal hydride batteries made of nanocrystalline nickel and
metal hydrides are envisioned to require less frequent recharging and
to last longer because of their large grain boundary (surface) area.
7. Catalysts
In general, nanoparticles have a high surface area, and hence provide
higher catalytic activity.

55. 8. Magnetic Nano Materials applications
• It has been shown that magnets made of nanocrystalline yttrium–
samarium–cobalt grains possess unusual magnetic properties due
to their extremely large grain interface area (high coercivity can be
obtained because magnetization flips cannot easily propagate past
the grain boundaries).
• This could lead to applications in motors, analytical instruments
like magnetic resonance imaging (MRI), used widely in hospitals,
and microsensors.
• Nanoscale-fabricated magnetic materials also have applications in
data storage.
• Devices such as computer hard disks storage capacity is increased
with Magnetic Nano materials

56. .
• Unfortunately, in some cases, the biomedical metal alloys may wear
out within the lifetime of the patient. But Nano materials increases
the life time of the implant materials.
• Nanocrystalline zirconium oxide (zirconia) is hard, wear resistant,
bio-corrosion resistant and bio-compatible.
• It therefore presents an attractive alternative material for implants.
• Nanocrystalline silicon carbide is a candidate material for artificial
heart valves primarily because of its low weight, high strength and
inertness.
9. Medical Implantation
10. Water purification
•Nano-engineered membranes could potentially lead to more energy-
efficient water purification processes, notably in desalination process.

57. 11. Military Battle Suits
• Enhanced nanomaterials form the basis of a state-of- the-art
‘battle suit’ that is being developed.
• A short-term development is likely to be energy-absorbing
materials that will withstand blast waves;
• longer-term are those that incorporate sensors to detect or
respond to chemical and biological weapons (for example,
responsive nanopores that ‘close’ upon detection of a
biological agent).

58. Preparation of Nanomaterials
Physical Methods Chemical Methods
Ball Milling Sputtering/
Evaporation
Electro-
Deposition
Chemical
reactions
Chemical vapor
Deposition