What is Molecularly Imprinted Polymer (MIP)?

This technology has been evolved for detection of explosives, MIPs for toxins, chemical agents, biological agents, pesticides, poisons, elements, chemical compounds and an apparatus for detecting mines and improvised explosive devices (IEDs) buried in the ground.

This technology is an exciting opportunity to begin showcasing the wide range of applications and advantages of customized macromolecules.

Some Facts About MIP's

  • A MIP is generally described as a plastic cast or mold of a molecule of interest, wherein recognition is based on shape, much like a lock and key. MIPs are made by adding the molecule of interest to a solution of binding molecules that can be chemically incorporated into a polymer. The binders usually have an affinity for the target molecule and form a complex.
  • Because of their highly cross-linked nature, MIPs are intrinsically stable and robust, facilitating their application in extreme environments, such as in the presence of acids, bases, or metal ions, in organic solvents, or at high temperatures and pressures.
  • MIPs can be stored in a dry state at room temperature for long periods of time.
  • How Are MIP's Made?
  • Molecularly imprinted polymers are made by first building a complex of a target molecule and associated binding molecules that possess the ability to be incorporated into a polymer. The complex is usually dissolved in a larger amount of other polymerizable molecules.
  • The bulk of the polymer is made with cross linking monomers. These molecules have two places to bind to the polymer chain to form a rigid three-dimensional structure. The cross linkers are necessary to hold the complex molecules in place after the target molecule, or "template" is removed.
  • It is also usual to add a solvent to the mixture. The solvent molecules get caught up in the growing polymer and leave gaps and pores in the structure to make the target complexes more accessible after the polymer is formed. Typically, after polymerization, a chunk of plastic is obtained. This chunk is ground up into a powder and the target molecule is removed by washing with the appropriate solvent. The powder is left with special holes that have a memory for the target molecule and are ready to time recapture that specific molecule the next it comes along.

MIP's As Sensor

There are two significant tasks that must be accomplished in the development of a reliable MIP sensor:

  • The development of a specific chemical recognition element that allows a molecule or a class of molecules, to be identified as explained above.
  • A means of signal transduction in which the presence of the molecule causes a measurable change in the physical property of the material. Johns Hopkins University/Applied Physics Laboratory (JHU/APL) has developed an optical transducer that undergoes a detectable change in absorption and/or emission of electromagnetic radiation when the target molecule binds with the MIP. The spectrum of light emitted by the MIP on excitation by ultraviolet (UV) light is the easiest way to display the result of target molecule detection. For example, a subway or train ticket coated with the MIP will emit a certain spectrum of light if it has been in contact with microscopic quantities of a target explosive. An optical reader, for detecting the light, is comprised of an (UV) LED and a simple light sensor. The reader consumes low power and is the size of a matchbox. Currently, Johns Hopkins University/Applied Physics Laboratory (JHU/APL) is developing a transduction method that will provide an electrical output so as to easily connect to Link Plus' mesh communications network.

Applications

  • Internal Security
  • Transportation Security
  • Chemical Sniffers
  • Buildings Access Control / Offices / Residences
  • Military and Defence
  • IED Detection
  • VIP Protection
  • Leakage Control
  • Environmental Monitoring and Control
  • Manufacturing Processes Control
  • Air Flow Control in Buildings
  • Forensic Applications
  • Medical Applications
  • Flavors and Fragrances Control
  • Nonintrusive Substances Control