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Researchers Submit Patent Application, "Molecularly Imprinted Polymers for Detection of Contaminants", for Approval

September 4, 2014

By a News Reporter-Staff News Editor at Politics & Government Week -- From Washington, D.C., VerticalNews journalists report that a patent application by the inventor Belbruno, Joseph J. (Hanover, NH), filed on August 30, 2012, was made available online on August 21, 2014.

The patent's assignee is The Trustees Of Dartmouth College.

News editors obtained the following quote from the background information supplied by the inventors: "Molecular imprinting is a technique that is used to produce molecule specific receptors analogous to biological receptor binding sites. Molecular imprinting of a polymer creates a molecularly imprinted polymer (MIP). An MIP is a polymer that is formed in the presence of a template molecule. The template molecule is removed and leaves a complementary cavity behind in the MIP. The MIP formed demonstrates affinity for the original template molecule.

"Sensors for most airborne contaminants are generally active. For example, the sensors require pumps to draw air through a tube. The sensors also require complex analysis after adsorption of the airborne contaminants, and various extracted components must be separated prior to analysis. Furthermore, the sensors are not specific for a single airborne contaminant. The sensors are also not real-time, and only provide an indication of toxic levels in a post-exposure mode. Moreover, some airborne contaminants, such as cyclic volatile methyl siloxanes (cVMS), have been recognized as environmental problems, but there are currently no sensors available for these contaminants."

As a supplement to the background information on this patent application, VerticalNews correspondents also obtained the inventor's summary information for this patent application: "This disclosure relates to the field of molecularly imprinted polymers (MIP), and more specifically relates to sensors that include MIP films to detect contaminants. The term contaminants as used herein may mean airborne contaminants, contaminants in a liquid solution, or both.

"MIPs disclosed herein may be used for sensors and/or solid phase extraction (SPE). Polymers used to produce the MIPs disclosed herein may be referred to as a polymer host. Molecules disclosed herein for the production of the MIPs may be referred to as a template, a target, or a target molecule.

"Embodiments of the sensors provided for herein allow for the detection of even a single kind of airborne contaminant The disclosure provides methods to produce a sensor including a conductive MIP film. The methods involve using the target molecule in the preparation of the MIP films and sensors comprising MIP films. When the target molecule is removed, it leaves behind a MIP with cavities that are complementary in shape and functionality to the target molecule, which can rebind a target identical to the original target molecule in those cavities.

"Certain non-limiting embodiments of the MIP sensors provided for herein have conductive elements incorporating thin polyaniline/polyethyleneimine (PANi/PEI) composite films prepared by spin-casting. Certain non-limiting embodiments of the MIP sensors are for formaldehyde detection via changes in conductivity of the MIP. Significant increases in the resistance of these MIP sensor films happen upon exposure to formaldehyde vapor. The films disclosed herein are responsive to other volatile organics, but the response of the films to non-target molecules is significantly reduced. In certain embodiments disclosed herein, detection of a target molecule occurs with changes in the resistance of the MIP. Significant increases in the resistance of the imprinted films occurs when exposed to a target molecule such when compared to control films involving coating with unimprinted polymer. In a non-limiting embodiment, polyvinylpyrrolidinone (PVPy) can be used as a polymer host in a MIP which can then coated onto conductive surfaces such as single-walled carbon nanotubes (SWNT). In general, MIPs can be coated onto carbon nanotubes. In an embodiment, an MIP made from PVPy with cotinine as a target molecule can be coated onto SWNTs. These MIP coated SWNTs can then be applied to a surface such as an electrode to form a sensor for the target molecule.

"An embodiment of this disclosure provides for sensors that can be developed to detect a wide range of target molecules using SWNTs coated with MIPs. In one embodiment, reusable SWNT MIP coated sensors created for the detection of cotinine are disclosed.

"Additional embodiments and features are set forth in part in the description that follows, and in part will become apparent to those skilled in the art upon examination of the specification or may be learned by the practice of the disclosure. A further understanding of the nature and advantages of the present disclosure may be realized by reference to the remaining portions of the specification and the drawings, which forms a part of this disclosure.


"FIG. 1 illustrates a simplified molecularly imprinted polymer solution in an embodiment.

"FIG. 2 is a flow chart illustrating the steps of a modified phase inversion process for producing MIPs, in an embodiment.

"FIG. 3A illustrates an exemplary test strip in an embodiment.

"FIG. 3B illustrates an exemplary test strip with water spray containing color reagents in an embodiment.

"FIG. 3C illustrates an exemplary test strip in a vial with liquid color reagents in an embodiment.

"FIG. 3D illustrates an exemplary test strip with color reagents covalently bonded to the MIP film in an embodiment.

"FIG. 4 illustrates an exemplary multi-band test strip in an embodiment.

"FIG. 5 illustrates an exemplary patch tester in an embodiment.

"FIG. 6 illustrates an exemplary conductive sensor including an MIP film in an embodiment.

"FIG. 7 illustrates a prototype sensor in an embodiment.

"FIG. 8. Schematic diagram of the lithographic circuit for a sensor with interdigitated electrodes:of 40 .mu.m and a spacing of 20 .mu.m.

"FIG. 9. Schematic drawings of the vapor calibration chamber (left) and the static test chamber (right)

"FIG. 10. SEM images of 5% PANi (left) and 5% PANi/5% PEI films (right).

"FIG. 11. Relative resistance as a function of temperature for exposure of the polymer film to formaldehyde in the static chamber.

"FIG. 12. Plot of film response as a function of concentration (upper) and the time response of exposure of the film to a vaporized sample formalin or approximately 170 ppm of formaldehyde (lower).

"FIG. 13. Relative resistance as a function of exposure of the polymer film to 100% samples of formaldehyde, water and other volatile organic molecules."

For additional information on this patent application, see: Belbruno, Joseph J. Molecularly Imprinted Polymers for Detection of Contaminants. Filed August 30, 2012 and posted August 21, 2014. Patent URL:

Keywords for this news article include: Nanotube, Formaldehyde, Nanotechnology, Emerging Technologies, The Trustees Of Dartmouth College.

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Source: Politics & Government Week

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