What is Nanotechnology
An engineered DNA strandtiny motor
junction formed by
two carbon nanotubes
Nanotechnology is the creation of functional materials, devices and
systems, through the understanding and control of matter at
dimensions in the nanometer scale length (1-100 nm), where new
properties of matter are observed and
harnessed for a broad range of applications.
What is Nanoscale
1.27 × 107 m
10 millions times
0.7 × 10-9 m
1 billion times
What Are Gold Nanoparticles?
• Gold nanoparticles (‘nanogold’) occur as
clusters of gold atoms up to 100nm in
• Nanogold has unusual visible properties
because the particles are small enough
to scatter visible light.
- in contrast, mass gold reflects light.
5nm gold clusters
Gold nanoparticles appear yellow to deep red to in solution.
- colour depends on size of nanoparticles
The distance between particles also affects colour
- surface plasmon resonance is the term used by
nanotechnologists to describe this effect.
Why Gold Nanoparticles
Cancer is a difficult disease to treat, contain, and identify.
There are many different ways for treating cancer such as surgery,
chemotherapy, radiation and many others. These methods are
effective if the cancer tumor is caught soon enough. However, these
treatments are not effective enough because they do not only target
the affected cells, they also affect healthy cells.
• Gold Nanoparticles are non toxic
• With Gold Nanoparticles we can detecting cancer
cells and even destroy them without affect healthy
Mostafa A. El-Sayed
Julius Brown Chair and Regents Professor;
Director, Laser Dynamics Laboratory
“Gold nanoparticles are very good at scattering and
absorbing light,” said Mostafa El-Sayed, director of the
Laser Dyanamics Laboratory and chemistry professor at
Georgia Tech. “We wanted to see if we could harness that
scattering property in a living cell to make cancer
detection easier. So far, the results are extremely
Gold Nanoparticle Tumor Detection
The common strategy to detect the tumor is the functionalization
of the nanoparticle with an antibody specific to the tumor
antigens, and then detect the nanoparticle by some spectroscopic
Imaging with gold nanoparticles
as contrast agent
Many cancer cells have a protein, known as Epidermal Growth Factor
Receptor (EFGR), all over their surface, while healthy cells typically
do not express the protein as strongly. By conjugating, or binding, the
gold nanoparticles to an antibody for EFGR, suitably named antiEFGR, researchers were able to get the nanoparticles to attach
themselves to the cancer cells.
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“If you add this conjugated nanoparticle solution to healthy cells and
cancerous cells and you look at the image, you can tell with a simple
microscope that the whole cancer cell is shining,” said El-
Sayed. “The healthy cell doesn’t bind to the nanoparticles
specifically, so you don’t see where the cells are. With this technique,
if you see a well defined cell glowing, that’s cancer.”
The heated nanoparticles.
Chemical therapy carried by nanoparticles.
Gold is a very good
so cells of cancer
become hot much
faster then healthy
malignant tumor is
Gold nanoparticles are able to be heated up by radio
The heated nanoparticles would in turn heat the cancer
cell up which would destroy the cancer cell. These radio
waves would not harm healthy cells. Infrared light waves
can be used in place of radio waves to heat up the cancer
cells for destruction.
Nanoparticles carrying chemical therapy show great promise in
treating cancer patients. One type of chemical that the nanoparticles
can carry is docetaxel which is currently used in treating cancer.
The outside of these nanoparticles are coated with proteins that link
directly to the cancer cells (antibody for EFGR) . The nanoparticles
also contain polyethylene glycol molecules that help stop the internal
defenses of a tumor cell. Although docetaxel is one type of chemical
used, there are many more that can be used.
1. Frens, G. Controlled nucleation for the regulation of the particle size in
monodisperse gold suspensions. Nat. Phys. Sci., 241: 20–22, 1973.
2. NCI Web site: http://cancer.gov/cancertopics/understandingcancer