Science Fair Project - Jing Guo's Homepage

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Transcript Science Fair Project - Jing Guo's Homepage

Nanobiotechnology and its
Chris Wright
Nick D’Souza
Kyle Ramirez
What is Nanobiotechnology?
Biotechnology is the application of technological
innovation as it pertains to biological and life sciences.
Nanobiotechnology incorporates biotechnology on the
Size Ranges of Biological Material
• Cells: 100um – 10um
• Cell organelles (nucleus,
mitochondrion): 10um – 1um
• Viruses: 100nm- 50nm
• Cell material (proteins, lipids,
DNA, RNA): 10nm – 0.1nm
Nanobiotechnology is an emerging field
• cells discovered 1665
• electron microscope 1950s
• Watson and Crick discover DNA double helix 1953
• Mapping of Human Genome 2003
Where is nanobiotechnology going? Applications?
Cell structure and physiology
Virus Detection
Drug delivery
Neurological functions of the brain
Biomedical engineering research
Study of molecular behavior
Utilization of imaging devices
Brain-Machine Interface
Brain-machine interface (BMI) is a fabricated
system to interpret voluntary brain activity
and convert to a mechanical movement
• Physiology:
Electrical signals in brain → spinal
cord → skeletal muscle
• BMI needed for individuals with:
spinal cord injury, or Parkinson’s disease
Brain-Machine Interface
Procedures involved:
1) mapping of brain target specific neurons
2) electrode implantation
3) signal acquisition
4) wireless transmission
5) signal processing
6) mechanical action
Study of DNA
• DNA molecules, under the influence of an electric field, are
forced through nano-scale channels (~100 nm) on a “gel
biochip”. The molecules deform and stretch to pass
through the small channels.
• This process separates DNA
fragments by length. This is
part of the method used to
sequence the DNA in the
human genome and in
identifying a unique DNA
Nanomechanical Oscillator
• A nano-scale cantilevered beam can be used to detect the
presence of viruses and bacteria and find their masses.
• The beam can be coated with antibodies specific to a
particular virus and then put into a substance to attract that
virus. The oscillation of the beam can then be measured
and compared to the oscillation before exposure to the
A nano-scale cantilevered beam is
placed in a solution, which is
known to contain E. coli
bacterium. The beam is removed
with a sample of E. coli bacterium
attached to it. The frequency of
vibration is measured and
compared to the frequency before
it was exposed to the E. coli.
How many individual cells of E.
coli bacterium are on the beam?
Given: wo,before = 1.091 MHz
wo,after = 1.070 MHz
5 E. coli
mE. coli cell = 665 x 10-15 grams
mbeam = 365 x 10-10 grams
Imaging Devices
• Atomic Force
Microscopy (AFM)
• Scanning Tunneling
Microscopy (STM)
Imaging Devices
• AFM and STM are used for
better resolution of nano-particles.
•Analysis includes bacteria and
protein structure, force
measurements within particles,
and virus-host interactions.
Imaging Devices
West-Nile Study
•AFM has become the main source of imaging for
analysis of virus-host interactions.
•A study involving the West-Nile virus gave a more
detailed view of the stages the virus goes through
during infection.
•The images produced reveal changes in plasma
and viral budding; this is essential for tracking down
the virus’ replication methods.
An STM is used to analyze a virus
sample. A 350mV potential is
applied across the tungsten tip
(work function of 4.8eV) and
the surface of the sample. If the
tunneling probability is 10-8,
what is the tunneling current
that results? As the tip is moved
across the surface the current
increases by 50mA. What is the
resulting tip-to-sample
separation, and what effect
does this have on the tunneling
Given: T=10-8; V=350mV; Φ=4.8eV;
m=9.1*10-31 kg
• Solve for electric field, E
• From there obtain tip-to-sample separation, d
• Tunneling current involves a decay constant, k. determine this constant from
virus mass and work function, Φ.
• Now solve for current.
• Make sure units are correct so that they cancel out properly.