CHEMISTRY

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CHEMISTRY PHYSICS OF THE BIOSENSOR More of
the Capture Membrane!
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Polyaniline and CNTs are used in the Capture
Membrane
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POLYANILINE an important nanotech plastic

• A conducting, organic plastic often used with
  CNTs
• 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).

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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)
• Its easy to make required shapes with pani
• No environmental problems with disposal

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PANI applications since 2000

• Electronics
• Super-capacitors
• Super-magnets
• Integrated circuits
• Luminescent diodes
• Sensors

• Chemical Power sources
• Conductive fabrics
• Anti static coatings

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PANI/CNT SENSORS

• POLYANILINE attached to CNT can become excellent
  sensors of bacteria viruses!
• Why would we want to develop this????

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Earlier you found out what Temperatures and PHs
PANI was more conductive at.

• What were your results??
• Do you remember??

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The Biosensor its basic parts
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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? Whats practical here?

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The Capture Membrane the Circuit Diagram
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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.

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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 its
  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!