Molecularly Imprinted Polymers

Abstract

The present invention relates to a molecularly imprinted polymer, comprising a functionalized polymer composition configured to molecularly bind a target molecule in a medium, wherein a chelating agent is molecularly bound to the functionalized polymer composition of the molecularly imprinted polymer. The chelating agent is releasable into the medium and, upon release from the molecularly imprinted polymer, is capable of inducing a change in the electrochemical properties of the medium. The chelating agent is configured to be released from the molecularly imprinted polymer into the medium by molecular binding between the target molecule and the functionalized polymer composition of the molecularly imprinted polymer.

Description

[Technical field]

[0001] The present invention relates to a molecular imprinted polymer, a method for carrying out a molecular imprinted polymer displacement assay, and a sensor device comprising the molecular imprinted polymer of the present invention for carrying out the method of the present invention.Furthermore, the present invention relates to the use of the molecular imprinted polymer in the detection and / or quantification of target molecules.The present invention further relates to a method for preparing the molecular imprinted polymer of the present invention. [Background technology]

[0002] Molecularly imprinted polymers (MIPs) are polymeric materials that contain microscale cavities or imprints with defined shapes. To create the imprints, a target molecule is introduced into a solution containing polymerizable molecules that bind to the target molecule. Then, by changing the reaction conditions or adding a cross-linking reagent to the solution, the polymerizable molecules form a solid polymer matrix in which the target molecule is immobilized. Finally, the target molecule is removed from the polymer matrix, forming an imprint with a specific shape. When the MIP thus formed is exposed to an environment containing a mixture of compounds, it can selectively bind molecules that match the shape of the imprint in a lock-and-key type interaction.

[0003] Typically, sensors based on molecularly imprinted polymers include molecularly imprinted polymer particles deposited on a flat substrate surface that forms a receptor layer for binding target molecules of a sample. The deposition of the MIP layer on the flat substrate surface involves fixing the MIP particles to the substrate using an adhesive or by chemically binding the MIP particles to the flat substrate surface. The process of depositing the MIP particles on the flat substrate surface is non-uniform, leading to high within-sample variability, as variations in MIP particle size lead to differences in the sensitivity of the sensor at a particular spot on the flat substrate surface. Furthermore, the flat substrate surface with the MIP particles deposited is placed next to or on top of a transducer inside the sensor. Measurements are typically made across the receptor layer to convert the binding event, i.e. the binding of the target molecules of the sample with the MIP particles, into a specific property (e.g., a change in mass, a change in impedance, a change in thermal resistance, etc.).

[0004] An example of an imprinted polymer-based sensor known in the art is shown (schematically) in FIG. 1. FIG. 1 shows a conductive surface (flat substrate surface) on which a MIP receptor layer is deposited. The receptor layer is placed inside the sensor with gold electrodes to measure the change in impedance. Considering the imprinted polymer-based sensors known in the art (shown in FIG. 1), it is noted that the design of the sensor is complicated because the receptor layer is placed next to or on top of the transducer. As a result, the design of the sensor is limited by the dimensions of the conductive surface and its position relative to the transducer, limiting the surface area of ​​the receptor layer that can interact with target molecules contained in the sample to be analyzed.

[0005] In addition to the above-mentioned drawbacks, it is further noted that the sensitivity of imprinted polymer-based sensors known in the art is limited by the tangible property (e.g., change in mass, change in impedance, change in thermal resistance, etc.) that is measured due to the binding of target molecules to the MIP receptor layer. Summary of the Invention

[0006] In order to reduce the complexity, improve the design flexibility and / or improve the sensitivity of the imprinted polymer-based sensors known to date, the present invention provides a molecular imprinted polymer, comprising a functionalized polymer composition configured to molecularly bind a target molecule in a medium, and a chelating agent is molecularly bound to the functionalized polymer composition of the molecular imprinted polymer. The chelating agent molecularly bound to the functionalized polymer composition of the molecular imprinted polymer of the present invention is releasable into the medium and can then induce a change in the electrochemical properties of the medium upon release from the molecular imprinted polymer. In order to correlate the change in the electrochemical properties of the medium with the detection and / or quantification of the target molecule, the chelating agent is configured to be released from the molecular imprinted polymer into the medium by the molecular binding of the target molecule to the functionalized polymer composition of the molecular imprinted polymer.

[0007] By providing the molecular imprinted polymer of the present invention, it has been found that the present invention provides a methodology in which the displacement of the chelating agent (in the case of the binding event of the target molecule to the functionalized polymer composition of the molecular imprinted polymer) results in a change in the electrochemical properties of the medium in which the chelating agent is released. For example, when an ion-binding chelating agent is used in the molecular imprinted polymer of the present invention, the chelating agent interacts with the ions contained in the medium. The interaction of the ions with the chelating agent results in a change in the electric potential of the medium. Instead of measuring the actual binding of the target molecule to the molecular imprinted polymer of the present invention, an indirect measurement is provided, which increases the sensitivity of the sensor based on the molecular imprinted polymer of the present invention.

[0008] By measuring the changing electrochemical properties of the medium containing the target molecule, it is not necessary to measure the actual binding event between the target molecule and the receptor layer contained in the sensor. In other words, the measurement of the changing electrochemical properties of the medium can be (and preferably is) performed at a location away from the actual target molecule-MIP interaction site. As a result, the sensor design is less complicated. An example of such a simplified sensor design including the molecularly imprinted polymer of the present invention is shown (schematically) in FIG. 2. FIG. 2 shows a measurement device (sensor including gold electrodes) with a filter loaded with the molecularly imprinted polymer of the present invention placed upstream. The sample medium flows through the filter loaded with the MIP to the measurement device. The binding of the target molecule contained in the sample medium promotes the release of the chelating agent, which changes the properties of the medium released from the filter. The change in the properties of the medium is then measured by a measurement device placed at some distance from the filter loaded with the molecularly imprinted polymer of the present invention.

[0009] The use of the molecular imprinted polymer of the present invention also solves the problems of non-uniform sensor design and intra-sample variability, since the molecular imprinted polymer of the present invention does not need to be deposited on a substrate surface. The present invention provides a sensor based on the molecular imprinted polymer of the present invention, where the molecular imprinted polymer of the present invention can be packed in a column and / or placed on a filter, separate from the actual sensor (i.e., the medium property measuring device). Thus, in designing a sensor based on the molecular imprinted polymer of the present invention, the sensor design is no longer limited by the surface area of ​​the substrate inside the sensor device as known so far.

[0010] Furthermore, by providing the molecularly imprinted polymer of the present invention, the present invention provides a MIP-based sensor in which the binding site of the target molecule to the MIP receptor layer is no longer two-dimensional but three-dimensional, such a three-dimensional design significantly increases the interaction surface area between the molecularly imprinted polymer of the present invention and the target molecule of the sample, thus significantly improving the sensitivity of the sensor based on the molecularly imprinted polymer of the present invention.

[0011] Also, in consideration of the molecularly imprinted polymer of the present invention, it should be noted that the present invention provides an in-line sensing method and / or a continuous sensing method. Furthermore, since the deposition step of depositing a molecularly imprinted polymer layer on a substrate surface is no longer necessary or applicable, the molecularly imprinted polymer of the present invention is commercially more attractive, including lower manufacturing costs. [Brief description of the drawings]

[0012] [Figure 1] FIG. 2 shows a conductive surface (flat substrate surface) onto which a MIP receptor layer is deposited. [Diagram 2] FIG. 1 shows a measurement device (sensor containing a gold electrode) with a filter filled with a molecularly imprinted polymer of the present invention placed upstream. [Diagram 3] FIG. 2 is a schematic diagram showing incubation or pre-loading of a functionalized polymer composition with a chelating agent. [Figure 4A] FIG. 13 shows the raw change in impedance versus time observed when amoxicillin solutions ranging in concentration from 0.01 nM to 100 nM were applied across the sensor. [Figure 4B] The concentration of amoxicillin solution is plotted against the change in impedance to show the relationship between the two variables. [Figure 4C] FIG. 4C shows the relationship between concentration and change in impedance when a logarithmic scale is introduced to the x-axis of FIG. 4B. [Figure 4D] 13A-13C show the results of initial experiments to see if the sensor works in complex environments. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0013] As provided above, in a first aspect, the present invention relates to a molecular imprinted polymer, comprising a functionalized polymer composition configured to molecularly bind a target molecule in a medium, and a chelating agent is molecularly bound to the functionalized polymer composition of the molecular imprinted polymer. The chelating agent molecularly bound to the functionalized polymer composition of the molecular imprinted polymer of the present invention is releasable to the medium, and can then induce a change in the electrochemical properties of the medium when released from the molecular imprinted polymer. To correlate the change in the electrochemical properties of the medium with the detection and / or quantification of the target molecule, the chelating agent is configured to be released from the molecular imprinted polymer into the medium by molecular binding of the target molecule to the functionalized polymer composition of the molecular imprinted polymer. Preferably, the molecular imprinted polymer of the present invention may be suitable for use in a displacement assay, where the chelating agent of the molecular imprinted polymer is configured to be released from the molecular imprinted polymer into the medium by displacement of the chelating agent with the target molecule.

[0014] The term "functionalized polymer composition" as used herein refers to a synthetic polymer that has been tailored to selectively bind a specific compound or combination of specific compounds. Functionalized polymer compositions are synthesized in the presence of a target compound, also called a template compound, to create MIPs with high affinity for specific target compounds. In general, the polymer is composed of spatially oriented ligands that form cavities that match the shape of the associated target compound. Specifically, the target compound is incorporated into a prepolymer mixture and bound to the ligands. This mixture is then polymerized in the presence of the target compound. Once the polymer is formed, the target compound is removed, leaving behind cavities corresponding to the target compound. Such cavities are tailored to bind future target compounds.

[0015] It is worth noting that while a specific target compound is used to form the functionalized polymer composition, the polymer may have a high affinity for a group of compounds similar to the target compound, thus providing a molecularly imprinted polymer capable of binding a large number of compounds that are similar in shape, charge density, structure, or other physical or chemical properties.

[0016] In particular, the functionalized polymer compositions of the present invention preferably comprise a monomer that contains one or more functional groups crosslinked with a crosslinker that contains one or more functional groups.

[0017] As used herein, the terms "molecular binding," "molecularly binding," or "binding event" refer to the interaction of a functionalized polymer composition with a chelator or target molecule. Such binding events may also be referred to as "selective binding properties" and "selective binding interactions," and are intended to refer to the preferential and reversible binding exhibited by the imprinted polymer for its imprinted molecule compared to other non-imprinted molecules. Selective binding includes both the affinity and specificity of the imprinted polymer for its template molecule and the affinity and specificity of the imprinted polymer for the analyte (i.e., "target molecule" or "target analyte") to be detected by the molecular imprinted polymer-based sensor device of the present invention.

[0018] In the present specification, the term "chelating agent" refers to, for example, a sequestering agent capable of forming a chelate complex with the chelating agent in order to induce a change in the electrochemical properties of a medium containing a target molecule by forming a chelate complex between the chelating agent and an ion present in the medium. The chelating agent of the present invention is preferably capable of interacting with an ion in a medium containing a target molecule, i.e., capable of forming a chelate with an ion contained in the medium. Preferably, the ion contained in the medium is a metal ion.

[0019] Preferably, the term "chelating agent" as used herein refers to a molecule that contains two or more electron donor atoms that can form coordinate bonds with a single metal ion. The term "chelating agent" is understood to include chelating agents and their salts. For example, the term "chelating agent" includes citric acid and its salt forms.

[0020] The most common and widely used chelating agents coordinate to the metal atom through oxygen or nitrogen donor atoms, or both. Other less common chelating agents coordinate through sulfur in the form of -SH (thiol or mercapto) groups. After the first coordinate bond is formed, each donor atom that binds forms a ring with the metal atom. Chelating agents include Mg 2+ , Cu 2+ , Cu + , Ca 2+ , Hg 2+ , Hg + , Fe 3+ , Fe 2+ They may be bidentate, tridentate, tetradentate, etc., depending on whether they contain two, three, four or more donor atoms capable of binding to a metal atom, such as a chelate. By binding to a metal atom contained in a medium containing the target molecule, the chelate binding interaction can be monitored with readout techniques including impedance (conductivity / resistivity), potential, color change (by use of indicator dyes), etc., i.e. the electrochemical, e.g. ionic, properties of the medium can be monitored.

[0021] Suitable chelating agents that can be used in the molecular imprinted polymer of the present invention are preferably non-coloring and / or non-toxic chelating agents. Particularly preferably, the chelating agent molecularly bound to the functionalized polymer composition of the molecular imprinted polymer of the present invention does not contain dye molecules.

[0022] Suitable chelating agents may be selected from the group consisting of, but are not limited to, ethylenediaminetetraacetic acid (EDTA)-based chelating agents, dimercaprol-based chelating agents, citric acid, 2,2'-bis(diphenylphosphino)-1,1'-binaphthyl) (BINAP)-based chelating agents, and phosphonate-based chelating agents.

[0023] According to the present invention, a molecularly imprinted polymer is provided in which a chelating agent is molecularly bound to the functionalized polymer composition of the molecularly imprinted polymer. To provide the molecularly imprinted polymer of the present invention, the molecularly imprinted polymer is preloaded with a suitable chelating agent. As used herein, the term "preloaded" is intended to refer to a method of incubating a functionalized polymer composition with a chelating agent for a sufficient period of time, and then washing the incubated molecularly imprinted polymer until no chelating agent is detected in the washing medium. In this manner, preloading results in a molecularly imprinted polymer in which all or at least a majority (i.e., 90% or more, preferably 95% or more) of the cavities of the functionalized polymer composition are filled (or occupied) with the chelating agent. In this regard, please refer to FIG. 3 (schematic), which shows the incubation or preloading of a functionalized polymer composition with a chelating agent.

[0024] As used herein, the term "medium" may refer to a liquid, biological fluid or sample that may contain a target molecule. Preferably, the medium according to the present invention is an aqueous medium.

[0025] The molecularly imprinted polymer of the present invention may be in the form of particles such as powders, granules, beads, crystals, pellets, etc. By providing such molecularly imprinted polymers, the present invention facilitates packing of the molecularly imprinted polymer into a column, thereby significantly increasing the interaction surface area between the molecularly imprinted polymer of the present invention and the target molecules of a sample (resulting in a significant increase in sensitivity). In a second aspect, the present invention relates to a method of performing a molecular imprinted polymer displacement assay, the method comprising: a) providing a molecularly imprinted polymer according to the present invention; b) providing a medium containing a target molecule; c) incubating the molecularly imprinted polymer provided in step a) with the medium provided in step b); d) monitoring the electrochemical properties of the medium; Equipped with.

[0026] As used herein, the term "electrochemical property of the medium" may refer to the impedance, potential, conductivity and resistivity of the medium. The term "electrochemical property of the medium" may also refer to a color change of an ion indicator dye contained in the medium. In this regard, it is noted that monitoring the electrochemical property of the medium in step d) may include monitoring the impedance, potential, conductivity, resistivity, a color change of an ion indicator dye contained in the medium, and combinations thereof.

[0027] When an ion indicator dye is used in the displacement assay of the present invention, the ion indicator dye preferably has a low ionic affinity compared to the ionic affinity of the chelator molecularly bound (i.e. pre-loaded) to the molecularly imprinted polymer. The step c) of incubating the molecularly imprinted polymer with a medium comprises: exposing a quantity of the medium to the molecularly imprinted polymer; or causing a flow of the medium to flow through or over the molecularly imprinted polymer; It can be provided with:

[0028] The methods of performing the displacement assay provided by the present invention are suitable for applying a single sample to the molecularly imprinted polymer particles of the present invention, and for continuously or intermittently monitoring the flow of a medium through or over the molecularly imprinted polymer particles of the present invention.

[0029] Further, the method of performing the displacement assay of the present invention comprises: e) quantifying the target molecule based on the change in electrochemical property monitored in step d). The device may further include:

[0030] In a third aspect, the present invention relates to a sensor device for sensing a target molecule in a medium, the sensor device comprising a molecular imprinted polymer according to the first aspect of the present invention for performing a method according to the second aspect of the present invention.

[0031] The sensor device may comprise an inlet for supplying the medium to the sensor device and an outlet for discharging the medium from the sensor device. The sensor device may further comprise a monitor unit for monitoring an electrochemical property of the medium.

[0032] In a preferred embodiment of the present invention, the monitor unit of the sensor device is arranged downstream of the molecular imprinted polymer.By providing such an arrangement, the design of the sensor device is not complicated.In addition, by providing the monitor unit arranged downstream of the molecular imprinted polymer of the present invention, the flexibility and capacity (e.g., sensitivity) of the sensor device are further improved.

[0033] In a fourth aspect, the present invention relates to the use of the molecular imprinted polymer according to the present invention in the detection and / or quantification of a target molecule in a medium.For example, the present invention relates to the use of the molecular imprinted polymer according to the present invention in a molecular imprinted polymer displacement assay as described above. In a fifth aspect, the present invention relates to a method for preparing a molecularly imprinted polymer according to the present invention, the method comprising the steps of: i) preparing a functionalized polymer composition; ii) incubating the functionalized polymer composition with a chelating agent; iii) drying the functionalized polymer composition incubated with the chelating agent to form a molecularly imprinted polymer; Equipped with.

[0034] The method of the present invention comprises the steps of: after incubating the functionalized polymer composition with the chelating agent in step ii), washing the incubated functionalized polymer composition to remove excess chelating agent from the incubated functionalized polymer composition prior to drying the functionalized polymer composition incubated with the chelating agent in step iii) to form the molecularly imprinted polymer; The device may further include: EXAMPLES

[0035] Synthesis and analysis of molecularly imprinted polymers Synthesis and analysis of amoxicillin molecularly imprinted polymers were performed as described in a previous study by Lowdon et al. (“Colorimetric Sensing of Amoxicillin Facilitated by Molecularly Imprinted Polymers.” Polymers 13.13(2021):2221).

[0036] Synthesis of molecularly imprinted polymers The aqueous phase was prepared by mixing 300 mg of sodium dodecyl sulfate (SDS) in 60 mL of pure water and placing in a 100 mL RBF. An overhead stirrer was placed in the flask so that the stirrer blades were covered by the solution. Following this, the organic phase of the reaction was prepared by mixing the monomer (methacrylic acid), EGDMA, AIBN, amoxicillin, and DMSO in a vial and then purging both solutions with N2 for 15 minutes. After purging, the organic phase was introduced into the aqueous phase with vigorous stirring at 600-1400 rpm for 1 minute to form an emulsion. Stirring was stopped and the emulsion was exposed to UV light (BlueWave200) for 1 hour. After exposure, the solution was transferred to a centrifuge tube and spun at 4500 rpm for 5 minutes. Leaving the resulting polymer disk in the centrifuge tube, the supernatant was carefully removed and ethanol was introduced into the tube. The tube was shaken well to suspend the polymer powder and the centrifugation was repeated five more times. The thoroughly washed polymer powder was transferred to a glass vial and oven dried at 65°C for 12 hours. This resulted in a fine polymer powder with a defined particle size based on the number of revolutions initially used to mix the reactants. A non-imprinted reference composition was synthesized using the exact sample method, but without the presence of template molecules. Template extraction was monitored by FTIR and the spectra of the extracted polymer compositions were compared to that of amoxicillin.

[0037] Binding experiment (amoxicillin) To determine the binding affinity between the MIP and the non-imprinted polymer (NIP), a rebinding experiment was performed as follows. 5 mL of an aqueous solution of the molecular species (amoxicillin) at a concentration of 0.1-0.7 mM was added to 20 mg of MIP / NIP powder, and the resulting suspension was stirred for 90 min on a rocking table (125 rpm). After stirring, the filtrate of each sample was collected and analyzed using a Shimadzu 3600 model ultraviolet spectrophotometer to determine the amount of molecular species (C) remaining in the solution. f )'s λ max Next, MIP / NIP(S b The amounts of molecular species bound to ) were calculated from these observations and the corresponding binding isotherms were plotted. Binding experiment (EDTA)

[0038] The experiments on the binding of EDTA were carried out in a similar manner to that for amoxicillin, but with some modifications. 20 mg of MIP / NIP powder was added with 5 mL of an aqueous solution of the molecular species (EDTA) at concentrations between 0.1 and 0.7 mM, and the resulting suspension was stirred for 90 min on a rocking table (125 rpm). After stirring, the filtrate of each sample was taken and analyzed by complexometric titration. Briefly, the filtrate was titrated against an aqueous calcium chloride solution (0.01 mM) in the presence of Eriochrome Black T indicator dye (preparation of the indicator dye is described below), and the end point of the titration was determined by the change in the color of the solution from blue to pink. The concentration of EDTA present in the solution was therefore determined by the volume of calcium chloride solution titrated. This measurement was used to calculate the amount of EDTA bound to the MIP / NIP and the construction of the associated binding isotherm as performed in the previous binding experiments.

[0039] Preparation of Eriochrome Black T indicator dye solution 0.5 g of Eriochrome Black T was dissolved in 50 mL of ethyl alcohol and buffered with a few drops of ammonia-ammonium chloride buffer (Preparation: Dissolve 67.5 g of ammonium chloride in 200 mL of water, add 570 mL of ammonia solution, and dilute to 1000 mL with water).

[0040] Preparation of aluminum substrate Samples were prepared according to Caldara et al. ("Thermal Detection of Glucose in Urine Using a Molecularly Imprinted Polymer as a Recognition Element" ACS sensors 6.12 (2021): 4515-4525). Aluminum plates were polished and cut to the desired dimensions (1 × 1 × 0.5 cm). 2). To immobilize the MIP particles, a PVC adhesive layer (4 wt% PVC dissolved in tetrahydrofuran) was deposited on the aluminum chip by spin coating (2000 rpm, 60 s, acceleration of 1000 rpm / s). A PDMS substrate covered with a monolayer of MIP particles was used to stamp the particles onto the PVC layer. The PVC layer was heated above its glass transition temperature (100 °C) for 2 h, allowing the beads to sink into the polymer layer. Before thermal measurements the samples were cooled and unbound particles were washed off with distilled water.

[0041] Impedance analysis of MIP For the analysis of the conventional receptor layer (in the flow cell), impedance analysis was performed using an MFIA impedance analyzer (Zurich Instruments) and a replica flow cell, as described by Arreguin-Campos et al. ("Biomimetic sensing of Escherichia coli at the solid-liquid interface: From surface-imprinted polymer synthesis towards real sample sensing in food safety." Microchemical Journal 169 (2021): 106554). A continuous frequency sweep of 200 points was performed in the range of 10 to 500,000 Hz, with a test signal of 300 mV. The initial signal was stabilized for 10 min in a solution containing calcium chloride (1.6 M), after which an amoxicillin solution (2 mL) was introduced into the flow cell at a rate of 4 mL / min and stabilized for another 10 min. This introduction was repeated for a range of amoxicillin concentrations (10 nM to 1 mM), ensuring that all solutions were prepared with the same concentration of electrolyte and followed the same stabilization period.

[0042] Preparation of EDTA-conjugated MIPs Conjugation of EDTA to amoxicillin MIP was performed by incubating 0.5 g of MIP powder with 50 mL of EDTA solution (1 mM) for 2 h. After this time, the EDTA-conjugated polymer particles were gravimetrically filtered and the collected powder was rinsed with 5x50 mL of pure water. After each wash, the filtrate was collected and analyzed for EDTA concentration by colorimetric titration (see supplementary section for methods and analytical results).

[0043] Preparation of receptors for impedance analysis Since the EDTA-conjugated MIP does not need to be deposited, instead, 25 mg of EDTA-conjugated MIP particles were suspended in pure water and loaded onto a PTFE filter (pore size 0.45 μm) by passing it through the PTFE filter for ease of use. Impedance analysis (EDTA substitution method)

[0044] The EDTA replacement that occurs when amoxicillin is incubated with EDTA-conjugated MIPs was performed using the same procedure as described above, but with some experimental differences. First, since the receptor in the flow cell is not needed, the internal substrate was replaced with another gold electrode (0.5 mm diameter) and placed parallel to the gold electrode already in place. Second, a 3D-printed polyacrylate-based lid, identical in dimensions and volume to the first lid, was replaced with the copper block. Finally, since the receptor could no longer fit inside the flow cell, a filter containing EDTA-conjugated MIPs was connected to the inlet tubing instead. The rest of the fabrication process was the same, and the same concentration range of amoxicillin (0.01 nM to 100 nM) was examined for direct comparison.

[0045] result The sensor was exposed to increasing concentrations of amoxicillin (the target molecule) in solution and impedance analysis of the assay was performed. Figure 4A shows the raw change in impedance versus time observed when amoxicillin solutions ranging in concentration from 0.01 nM to 100 nM were applied across the sensor. The system was first stabilized with a calcium chloride solution (1.6 mM to simulate the concentration in milk). As shown in Figure 4A, a change in impedance was observed after each concentration was injected, indicating that the chelator is interacting with ions in the solution, resulting in a change in impedance.

[0046] The concentration was then plotted against the change in impedance (Figure 4B) to show the relationship between the two variables (linear x-axis scale), while Figure 4C shows the relationship between concentration and change in impedance when a logarithmic scale is introduced on the x-axis.

[0047] Figure 4D shows the results of an initial experiment to see if the sensor would work in a complex environment. In this experiment, the sensor was stabilized in (whole) milk before introducing a spiked milk sample (containing 0.01 nM amoxicillin). As shown in Figure 4D, a clear change in impedance was observed. With the MIP of the present invention, more chemically complex samples can be analyzed, as shown by the clear change in impedance in Figure 4D.

[0048] It should be noted that the experiments were performed by passing the liquid sample through a filter in which 25 mg of MIP powder loaded with EDTA was present. However, it should be noted that by increasing the amount of MIP powder present on the filter, the linear range of the sensor can be expanded, further improving the sensitivity of the method. As a result, the sensor of the present invention can be applied to a larger concentration range (from 1 picomolar to 1 millimolar).

Claims

1. 1. A molecularly imprinted polymer comprising a functionalized polymer composition configured for molecular binding of a target molecule in a medium, a chelating agent is molecularly bound to the functionalized polymer composition of the molecular imprinted polymer, the chelating agent being releasable into the medium and capable of inducing a change in the electrochemical properties of the medium upon release from the molecular imprinted polymer; The molecular imprinted polymer, characterized in that the chelating agent is configured to be released from the molecular imprinted polymer into the medium by molecular binding between the target molecule and the functionalized polymer composition of the molecular imprinted polymer.

2. 10. The molecularly imprinted polymer of claim 1, wherein the chelating agent is configured to be released from the molecular imprinted polymer into the medium by displacement of the chelating agent with the target molecule.

3. The molecularly imprinted polymer according to claim 1 , wherein the chelating agent is capable of forming a chelate with an ion contained in the medium, and preferably the ion contained in the medium is a metal ion.

4. The molecular imprinted polymer according to any of claims 1 to 3, wherein said chelating agent does not comprise dye molecules, preferably said chelating agent is selected from the group consisting of ethylenediaminetetraacetic acid based chelating agents, dimercaprol based chelating agents, citric acid, 2,2'-bis(diphenylphosphino)-1,1'-binaphthyl based chelating agents and phosphonate based chelating agents.

5. The molecularly imprinted polymer of any of claims 1 to 4, wherein the functionalized polymer composition is in the form of particles such as powders, granules, beads, crystals, pellets, and the like.

6. The molecularly imprinted polymer of any of claims 1 to 5, wherein the functionalized polymer composition comprises a monomer comprising one or more functional groups crosslinked with a crosslinker comprising one or more functional groups.

7. 1. A method for performing a molecular imprinted polymer displacement assay, comprising: a) providing a molecularly imprinted polymer according to any one of claims 1 to 6; b) providing a medium containing a target molecule; c) incubating the molecularly imprinted polymer provided in step a) with the medium provided in step b); d) monitoring the electrochemical properties of the medium; A method for performing a molecular imprinted polymer displacement assay comprising:

8. 8. The method of claim 7, wherein the electrochemical properties of the medium monitored in step d) include impedance, potential, conductivity, resistivity, color change of an ion indicator dye contained in the medium, and combinations thereof.

9. The method of claim 8, wherein the ion indicator dye has an ion affinity that is lower than the ion affinity of the chelating agent molecularly bound to the molecular imprinted polymer.

10. Step c) of incubating the molecularly imprinted polymer with a medium comprises: allowing a predetermined amount of said medium to act on said molecularly imprinted polymer; or causing a flow of said medium to flow through or over said molecularly imprinted polymer. The method according to any one of claims 7 to 9, comprising:

11. The assay comprising: e) quantifying said target molecule based on the change in electrochemical property monitored in step d). The method according to any one of claims 7 to 10, further comprising:

12. A sensor device for sensing a target molecule in a medium, comprising a molecular imprinted polymer according to any one of claims 1 to 6 for carrying out a method according to any one of claims 7 to 11.

13. The sensor device of claim 12, wherein the sensor device comprises an inlet for supplying the medium to the sensor device and an outlet for discharging the medium from the sensor device, and the sensor device further comprises a monitor unit for monitoring an electrochemical property of the medium, the monitor unit being positioned downstream of the molecular imprinted polymer.

14. Use of a molecularly imprinted polymer according to any one of claims 1 to 6 in the detection and / or quantification of a target molecule in a medium.

15. i) preparing a functionalized polymer composition; ii) incubating the functionalized polymer composition with a chelating agent; iii) drying the functionalized polymer composition incubated with the chelating agent to form a molecularly imprinted polymer; A method for preparing a molecularly imprinted polymer according to any one of claims 1 to 6, comprising:

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