STORAGE OF CODES IN MOLECULARLY IMPRINTED POLYMERS

Abstract

Disclosed is a molecularly imprinted polymer for storing a defined value of a numerical code, more particularly a binary code, in the molecular imprints of said polymer, and a method for the production of said polymer. The molecular imprinting process uses suitable templates comprising a defined sequence of at least two different structural units, each having a different chemical functionality.

Claims

1-22. (canceled)

23. A method for producing a molecularly imprinted polymer containing at least one defined value of a numerical code, comprising: storing the value of the numerical code in the polymer of the molecularly imprinted polymer by polymerizing the polymer in the presence of at least one template, the template being composed of a defined, selected sequence of structural components; and selecting the structural components from at least two types of structural components that differ from one another at least with respect to the side functionalities thereof; wherein templates having any sequence of the structural components thereof can be produced; wherein at the side functionalities of the template, monomers are bonded with the functional groups thereof that are complementary to the side functionalities; wherein the monomers differ from one another with respect to the functional groups thereof; and wherein the monomers are bonded when the polymerization takes place in the polymer structure of the polymer, and the template is subsequently released with the side functionalities thereof from the monomers, so that the molecularly imprinted polymer comprises a defined value of the numerical code, formed of the functional groups of successive monomers, corresponding to the selected sequence of the structural components of the template that was used to produce the molecularly imprinted polymer.

24. The method according to claim 23, wherein: two different types of template components and two different monomers are present; and the first monomer has an acidic group as the functional group and the second monomer has a basic group as the functional group.

25. The method according to claim 24, wherein the first monomer has a carboxyl group as the functional group and the second monomer has an amino group as the functional group.

26. The method according to claim 23, wherein the monomers are selected from the group consisting of: acrylic acid; methacrylic acid; crotonic acid; itaconic acid; fumaric acid; maleic acid; monomethyl itaconate; monomethyl fumarate; monobutyl fumarate; maleic anhydride; acrylamido glycolic acid; styrenesulfonic acid; vinylsulfonic acid; vinylphosphonic acid; 2-acrylamido-2-methylpropanephosphonic acid; 2-acrylamido-2-methyl-1-propanesulfonic acid; diallyl dimethyl ammonium chloride; dimethylaminoethyl (meth)acrylate; diethylaminoethyl (meth)acrylate; dimethylaminopropyl (meth)acrylate; 2-hydroxydimethylaminopropyl (meth)acrylate; aminoethyl (meth)acrylate and salts and quaternary compounds thereof; N,N-dimethylaminoethyl acrylamide; as well as derivatives of said monomers.

27. The method according to claim 23, wherein: the defined numerical code is formed of at least three monomers; and the sequence of the numerical code from monomers may be composed of identical monomers, or of different monomers.

28. The method according to claim 23, wherein the polymerization is carried out in the presence of at least two different templates that differ from one another with respect to the sequence of the side functionalities bonded thereto, so that the molecularly imprinted polymer contains at least two different defined values of a numerical code.

29. The method according to claim 23 for producing a molecularly imprinted polymer containing a defined value of a binary code, the method comprising the steps of: a. producing the template, the template being produced as a freely-definable sequence of template components having different chemical side functionalities, wherein one template side functionality can be recognized as logical 1 and one template side functionality can be recognized as logical 0; b. adding the monomers, which have complementary functional groups to the side functionalities of the template; c. self-organization by the monomers at the side functionalities of the template components via the complementary functional groups thereof; d. fixing the complementary binary code by polymerizing the monomers in order to produce the polymer; and e. removing the template from the polymer so that the functional groups of the monomers are exposed, such that the polymer exists as a molecularly imprinted polymer, wherein the sequence of the functional groups forms the defined value of the binary code.

30. The method according to claim 23, wherein a first side functionality of the template is a carboxyl group and a second side functionality of the template is a primary amino group.

31. The method according to claim 23, wherein: the template comprises a sequence of at least three template components; and the group of templates from which the template can be selected also includes templates that have only template components having one of the possible side functionalities.

32. The method according to claim 23, wherein the template components are selected from the group consisting of: basic or acidic amino acids; nucleotides; nucleotide derivatives; basic or acidic vinyl monomers; anionic or cationic monomer units; chemically cross-linkable structural units having omega-hydroxycarboxylic acids and an additional carboxy or amino function; and omega-amino acids having a carboxy or amino function.

33. The method according to claim 23, wherein the monomers are polymerized with the use of a cross-linker.

34. A method for reading out the stored information of a molecularly imprinted polymer that comprises a defined sequence of different functional groups with which the meaning of a defined value of a numerical code or binary code is associated, comprising: bringing the molecularly imprinted polymer into contact with a pool of analyte templates, wherein the analyte templates have different side functionalities that are complementary to the functional groups of the molecularly imprinted polymer, and wherein the analyte templates differ from one another with respect to the order of side functionalities thereof, so that that analyte template that has the sequence of side functionalities that is complementary to the functional groups binds specifically to a sequence of different functional groups of the numerical code of the molecularly imprinted polymer.

35. The method according to claim 34, wherein the pool of analyte templates contains the template complementary to the sequence of the functional groups as well as isomers, enantiomers, and/or variants of the complementary template.

36. The method according to claim 34, wherein the analyte template of the pool and monomers of the molecularly imprinted polymer that comprise the functional groups are isotopically labelled.

37. The method according to claim 36, wherein the information is read out by spatially-resolving dipolar solid state NMR.

38. A method for reading out the stored information of a molecularly imprinted polymer that is selectively provided with a defined sequence of different functional groups reflecting a stored value of a numerical code, wherein an anti-idiotypic method is used to read out the stored value, the method comprising: a. producing a pool of molecules that are template components having different side functionalities, wherein each template component has one side functionality that is complementary to one of the functional groups of the defined sequence; b. bringing the pool into contact with the molecularly imprinted polymer, wherein the imprint of the molecularly imprinted polymer that comprises the stored value of the numerical code acts as a reaction chamber, so that template components bind to the different functional groups of the imprint according to the respective side functionalities thereof, such that a replica of the template that may have been used or was used to produce the stored value of the numerical code is created in the imprint; and c. reading out the stored value by characterization of replicas by means of an analytical method.

39. The method according to claim 38, wherein the template components of the pool and monomers of the molecularly imprinted polymer that comprise the functional groups are isotopically labelled.

40. The method according to claim 39, wherein the information is read out by spatially-resolving dipolar solid state NMR.

41. A molecularly imprinted polymer containing a molecularly stored value of a numerical code, wherein the molecularly imprinted polymerand, thus, also the molecularly stored valuehas been produced according to the method according to claim 23.

42. The molecularly imprinted polymer according to claim 41, wherein the molecularly imprinted polymer is a foodstuff, a consumer good, or an industrial good, or a component and/or ingredient thereof, wherein the molecularly stored value makes it possible to identify the foodstuff, the consumer goods, or industrial goods, or contains information regarding the same.

43. Use of the molecularly imprinted polymer according to claim 41 to label, code for, and/or analyze products.

44. Use of the molecularly imprinted polymer according to claim 43 to recognize and/or code for foodstuffs, consumer goods, or industrial goods and/or components or ingredients thereof.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0051] The drawings provide a more detailed illustration, by way of example, of the method according to the invention on the basis of several embodiment variants. The drawings show:

[0052] FIG. 1. an exemplary template molecule having a binary code based on two different template components (lysine and glutamic acid);

[0053] FIG. 2. an exemplary template molecule in electrostatic interaction with corresponding, complementary functional monomers;

[0054] FIG. 3. the molecular imprint of the exemplary template molecule in the polymer, wherein the template molecule is still embedded;

[0055] FIG. 4. the molecular imprint of the exemplary template molecule in the polymer, after the template molecule has been removed;

[0056] FIG. 5. the specific recognition of the binary code stored in the molecular imprint of the polymer, through the template molecule; and

[0057] FIG. 6. the reading out of the stored binary code through spatially-resolved solid state NMR in the molecular imprint. Selective isotopic labelling of the molecular imprint or the monomer units and template molecules enables magnetic dipolar interactions.

[0058] In the chemical structural formula, PG stands for protecting group.

DETAILED DESCRIPTION

[0059] The octapeptide lysine-lysine-lysine-lysine-lysine-glutamic acid-glutamic acid-lysine is used as a template 1, by way of example (see FIG. 1). With lysine and glutamic acid, the template 1 has two different template components that differ from one another with respect to the side functionalities 2, 3 thereof. In the example of FIG. 1, the amino function, as the side functionality 2 of the lysine, acts as a binary 1 while the carboxyl function, as the side functionality 3 of the glutamic acid, acts as a binary 0. The following sequence of side functionalities 2, 3read from left to rightthus arises for the example template 1 depicted in FIG. 1: Amino-Amino-Amino-Amino-Amino-Carboxy-Carboxy-Amino, thus 11111001 as the value of the binary code 4.

[0060] The addition of at least two different monomers 5 having functional groups 6, 7 that are complementary to the side functionalities 2, 3 of the template 1 is followed then by a wait for the self-organization of the template 1 and monomers 5 via the functionalities thereof, so that the monomers 5 bind to the side functionalities 2, 3 according to the functional groups 6, 7 thereof, as is illustrated in FIG. 2.

[0061] Suitable monomers 5 thus contain complementary functional groups. Thus, as illustrated in the example, the first monomer 5methacrylic acid, with the functional group 6 thereofis complementary to the side functionality 2 in the form of the amino function of the template component lysine. The second monomer 5, in the form of 2-aminoethyl methacrylate with the functional group 7 thereof in the form of an amino-functionalized side chain, is complementary to the side functionality 3 in the form of the carboxy function of the template component glutamic acid. Thus, the functionally complementary monomers 5 organize themselves with the template components through the complementary functional groups thereof. In the example of FIG. 2, the acid function of the methacrylic acid organizes itself with the basic function of the lysine, and the basic function of the 2-aminoethyl methacrylate organizes itself with the acidic function of the glutamic acid of the octapeptide that forms the template 1. Electrostatic interactions thus form stable compounds.

[0062] After a cross-linking monomer has been added, the monomers 5 can be polymerized to thereby fix and store the complementary template structure and thus the binary code 4. Examples of suitable monomeric cross-linkers include ethylene glycol dimethacrylate, butylene glycol dimethacrylate (or butane-1,4-diol dimethacrylate), and hexamethylene dimethacrylate (or hexane-1,6-diol dimethacrylate).

[0063] In FIG. 3, the monomers 5 are depicted in the cross-linked state thereof, i.e., the monomers are components of a polymer 8 or are bonded to a polymer 8. As is represented, the template 1 is still bonded to the polymer 8 after the polymerization.

[0064] As depicted in FIG. 4, the template 1 is removed from the polymer 8. After the template 1 has been removed with the original binary code 4 thereof, then, the functionalities of the previous monomers 5 remain behind in the resulting molecular imprints of the polymer 8 in an immobilized configuration, such as the template 1 was set forth. The polymer 8, after the template 1 has been removed, thus exists as the molecularly imprinted polymer 9. The molecularly imprinted polymer 9 has, in an exposed state, the functional groups 6, 7 of the cross-linked monomers 5, which form the binary code 4 of the molecularly imprinted polymer 9, i.e., according to the example, the code sequence or the stored value 11111001.

[0065] As illustrated in FIG. 5, the thus-stored value of the binary code 4 is read out from the molecular imprints of the MIPs 9 according to a first variant according to the invention by stirring a mixture of analyte templates 10 also containing an analyte template 10 that corresponds to the original template 1 with a suspension of MIP particles, and measuring the residual content of the analyte templates 10 in the supernatant of the MIP particles after an adsorption phase. The content of the analyte template 10 that corresponds to the original template 1 is diminished in comparison to the other analyte template 10 because that analyte template 10 binds specifically as the sole molecule in the molecular imprints. This makes it possible to determine which value of the binary code 4 is present in the molecular imprint of the MIP 9. As shown, the analyte template 10 that has the sequence of side functionalities 2, 3 that is complementary to the sequence of the functional groups 6, 7 of the MIP 9 binds specifically to the imprint, i.e., the sequence 22222332 binds specifically to the sequence 66666776, i.e., according to the example, the side functionality sequence Amino-Amino-Amino-Amino-Amino-Carboxy-Carboxy-Amino of the template component sequence Lysine-Lysine-Lysine-Lysine-Lysine-Glutamic acid-Glutamic acid-Lysine binds to the functional group sequence Carboxy-Carboxy-Carboxy-Carboxy-Carboxy-Amino-Amino-Carboxy of the monomers 5.

[0066] According to a second readout method according to the invention, the binary code 4 may also be read out by adding solutions of chemical structural components of the original template molecules according to a type of anti-idiotypic method and then replicating these template molecules in the molecular imprints, it being possible to determine the code thereof after elution and analytical characterization. This second readout method according to the invention is thus performed by producing a pool of molecules that contain at least the original template components of the template 1 that was used to produce the MIP 9. This pool is brought into contact with the MIP 9, wherein the molecular imprint, i.e., the binary code 4, of the MIP 9 acts as a reaction chamber. The complementary template components of the pool bind to the molecular imprint, thereby producing replicas of the original templates 1. These replicas may be characterized by means of analytical methods, for example, by means of chromatographic methods, and thus the stored code 4 can be read out. The molecular imprint in the MIP 9 may act, on the one hand, as a copy room for replicating the original template 1, while the molecular imprint may also be used, on the other hand, to produce different variants or derivatives of the original template 1, depending on the choice of chemical components, with an unaltered sequence of the side group functionalities, i.e., of the binary code 4. In other words, the code in the MIP 9 can be used to produce duplicates or derivatives of the template 1, which can be used in turn as data or information carriers, or can be used to produce other MIPs 9. The MIPs 9 according to the invention can thus be copied or replicated.

[0067] FIG. 6 illustrates a method for reading out the stored binary code directly at the MIP 9 by spatially-resolving solid state NMR. NMR stands for nuclear magnetic resonance. It is to be provided according to the invention that the monomers 5 and the template component binding thereto have a selective isotopic labelling, which is achieved, for example, by selecting the nitrogen atoms of the amino functions and the carbon atoms of the carboxy functions of both the side functionalities 2, 3 of the template components and the functional groups 6, 7 of the monomers 5 in the form of .sup.15N and .sup.13C isotopes, respectively. With spatially-resolving, multi-nuclear, multi-dimensional solid state NMR, the binary code 4 is read out according to the invention by measuring a dipolar recoupling by means of rotational echo double resonance (REDOR) or radio frequency-driven recoupling (RFDR) spectroscopy on the basis of the aforementioned isotopic labelling, and thus being able to determine the structure and orientation of the template 1, or an identical analyte template 10, in the MIP 9 and thus the order of the functional groups 6, 7 in the MIP 9 and therewith the value of the binary code 4.

[0068] The isotopically labelled template components in the MIP 9 may, on the basis of the first readout method according to the invention, be bonded by bringing a pool of different isotopically labelled analyte templates 10 differing from one another in the order of the isotopically labelled template components thereof in contact with the MIP 9, so that only that isotopically labelled analyte template 10 that has the value of the binary code 4 of the original template 1 binds to the imprint of the MIP 9, as is illustrated in FIG. 6.

[0069] The second readout method according to the inventionwhich follows a type of anti-idiotypic methodmay preferably be carried out with isotopically labelled template components. The isotopically labelled template components bind with the respective side functionalities 2, 3 thereof to the complementary functional groups 6, 7 of the imprint, i.e., according to the order of the binary code 4, such that the isotopically labelled template components together form a duplicate or derivative of the original template 1, which exists according to the analyte template 10 of FIG. 6 in the isotopically labelled imprint of the MIP 9.

[0070] Because the measurable interaction between the isotopes of the bonded analyte template 10 and the isotopes of the monomers 5 differ according to the order of the arrangements thereof, the value of the binary code 4 can be determined directly at the MIP 9.

[0071] The molecularly imprinted polymers 9 described herein are produced in the presence of the template 1, preferably via a surface, precipitation, suspension, emulsion, or mass polymerization in a batch or semi-batch process, and put to use in different forms, preferably in the form of spherical particles, orespecially preferablyin the form of polymer coatings.

[0072] The spherical particles or polymer coatings may be used, for example, to encode for products of every kind. Due to the size down to the nanometer range, the MIPs 9 are invisible to the consumer when applied to long-lasting products, so that the origin thereof can be unambiguously determined even after a long period of time has passed. The MIPs 9 can thus contain, for example, detailed information on the actual origin of the original products, so that the products can be distinguished from counterfeits. Plastic matrices may be provided directly with the described molecular imprints and thus be encoded or generally put to use as data carriers. For example, specific manufacturer or customer data, or simply the date of production, may be left as a numerical value or in binary form in the imprint.

[0073] It is also possible to produce multi-MIPs 9, wherein a plurality of different templates 1 are used, in order to imprint, in parallel, different numerical codes, more particularly, binary codes 4 having different information into molecular imprints. One MIP 9 can thus comprise a plurality of different molecular imprints, which may differ from one another with respect to the code sequence and/or code length thereof.

[0074] Thus, another embodiment comprises MIPs 9 that contain at least two different values of a numerical code, more particularly, a binary code 4.

[0075] In one embodiment of the invention, the MIPs 9 are used to recognize and/or code for foodstuffs, consumer goods, industrial goods, and components or ingredients thereof.

Example 1

[0076] To produce a molecularly imprinted polymer 9 according to the invention as an example, the tripeptide glutamic acid-lysin-lysine (EKK) was used as the template 1. The value of the binary code 4 present in the amino acid sequence corresponds thus to 100. The formulation of this template polymer is set forth in table 1.

TABLE-US-00001 TABLE 1 Composition of the molecularly imprinted polymer (MIP1) with use of the template EKK, with molar mass, calculated and actually- measured mass of the substances, and the equivalents thereof Molar mass Substance g/mol Estimated Actual Equivalent Template EKK 625.31 15 mg 15.67 mg 1 Methacrylamide 86.04 33.00 mg 33.54 mg 15.6 Methacrylic acid 85.05 32.64 mg 33.65 mg 15.8 Ethylene glycol 198.22 237.75 mg 237.38 mg 47.8 dimethacrylate Azobisisobutyro- 164.21 1.17 mg 1.42 mg 0.35 nitrile Acetonitrile 41.05 3.75 mL 3.75 mL Di- 78.13 0.2 mL methylsulfoxide

[0077] With the exception of the initiator azobisisobutyronitrile, all of the components were dissolved in a mixture of acetonitrile and dimethyl sulfoxide. The solution was stirred for 4 hours in order to make it possible to create electrostatic interactions such as hydrogen bonds andin addition, after proton transferionic bonds between the template 1 and the functional monomers 5 methacrylamide and methacrylic acid. The initiator azobisisobutyronitrile is then added thereto, and the solution was sprayed for 5 minutes with gaseous nitrogen. Then, in a refrigerator at 6 C., the solution was placed in a UV reactor and subjected to 24 hours of UV radiation. The suspension formed was subsequently stirred for 24 hours with 6 mL of a methanol-acetic acid mixture (9:1, v:v), in order to purify the polymer 8 and, in particular, to remove the template molecules. The resulting molecularly imprinted polymer 9 was then filtered and washed twice with a methanol-acetic acid mixture and four times with acetonitrile. The molecularly imprinted polymer 9 was subjected to 5 more minutes of suction as a first round of drying. Further drying steps included spraying the solid with gaseous nitrogen for 5 minutes, and depositing in a drying oven at 40 C. for a period of 24 hours. The yield of the white-colored, powdery molecularly imprinted polymer 9 was 219.66 mg.

[0078] The template 1 (the tripeptide EKK) as analyte and other comparison analytes/analyte templates 10 (the tripeptides KEK, EKE, EEK, EEE) were each dissolved in 0.1 mL of dimethyl sulfoxide and 8 mL of acetonitrile, and the powdery MIP 9 was suspended therein. Table 2 lists the exact details of these affinity assays. These suspensions were each stirred for 18 hours at room temperature. 2 mL was then removed from each of these suspensions and centrifuged at a rotational speed of 10,000 RPM. The resulting supernatants were diluted with 8 mL of acetonitrile and the solutions were then subjected to spectroscopic measurement at a wavelength of 300 nm.

TABLE-US-00002 TABLE 2 Affinity assays with the molecularly imprinted polymer MIP1 with different tripeptides, the absolute masses used thereof, the masses of the molecularly imprinted polymer MIP1 used, and the measured concentrations of the tripeptides in the supernatant after reaching equilibrium. Concentration in Analyte supernatant based on (peptide Mass measured absorption sequence) of analyte/mg Mass of MIP/mg C.sub.calc, mg/mL KEK 2.11 10.43 0.073 EKK* 2.12 10.39 0.043 EKE 2.08 10.20 0.069 EEK 2.10 9.94 0.072 EEE 2.16 10.31 0.117 (E = glutamic acid, K = lysine) * corresponds to the original template molecule

[0079] This example showed that the MIP 1 has a particular affinity to the original template EKK (line marked with *), with an especially high adsorption due to specific molecular imprints, or with an especially low residual content in the supernatant of only 0.043 mg/mL, in comparison to the four other tripeptides KEK (0.073 mg/mL), EKE (0.069 mg/mL), EEK (0.072 mg/mL), and EEE (0.117 mg/mL). In this manner, it was possible to read back, from a key set of five tripeptide molecules (KEK, EKK, EKE, EEK, and EEE), the matching key (EKK) due to the stored information, i.e., the sequence EKK or the binary code 100.