Transcript 21-LESSON PLAN 7c

CHEMISTRY & PHYSICS OF
THE BIOSENSOR
More of the Capture Membrane!
Polyaniline and CNT’s are used in
the Capture Membrane
POLYANILINE: an important
nanotech plastic
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A conducting, organic plastic often used with CNT’s
Can tell whether an acid or base is in the air
Sensitivity to an acid or base increases with surface area
Surface area is determined in the creation of the
polyaniline by creating more bumps and valleys that are
nano size.
• The Conductivity changes due to exposure to acid
(vinegar) or a base (ammonia).
POLYANILINE: a material of
promise!
• The amount of required conductivity is designed into
the pani (polyaniline)
• It can be melted into a liquid easily
• Or it can be put into solution (like sugar & water)
• It’s easy to make required shapes with pani
• No environmental problems with disposal
PANI – applications since 2000
• Chemical Power
sources
• Conductive fabrics
• Anti static coatings
• Electronics
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Super-capacitors
Super-magnets
Integrated circuits
Luminescent diodes
Sensors
PANI/CNT SENSORS
• POLYANILINE attached to CNT can become
excellent sensors of bacteria & viruses!
• Why would we want to develop this????
Earlier you found out what
Temperatures and PH’s
PANI was more conductive at.
What were your results??
Do you remember??
The Biosensor & it’s basic parts
PHYSICS STUDENTS
• What do you think the circuit looks like?
• Is it a parallel or series circuit?
• What could be used that is small enough for a
voltage source?
• When the antigen is found – how will that close
the switch to send the electronic signal?
• How will we want to know that the signal has
been sent? What’s practical here?
The Capture Membrane & the
Circuit Diagram
Assignment A:
• You will be building a large scale biosensor
circuit.
• You will want to capture something large (such as
a magnet or a toy car) as it travels past your
circuit. This will be your switch.
• Use a voltage source of a battery of appropriate
size.
• When your switch is closed (on) have it light up
a light bulb or turn on a buzzer.
• Design into your circuit appropriate places for a
Ammeter.
Parameters of the Project
(teams of 2)
• Draw a circuit diagram and have your teacher
approve it.
• Make a list of supplies needed & have your
teacher approve it.
• Make a list of tests you should run once it’s
working & have your teacher approve it.
• Build it! Ask your teacher for help if you are
having trouble getting it to work.
• Run your tests! Analyze your data & write a
conclusion!