TWI427111B - Method for forming a molecular imprinted polymer film on a plastic substrate - Google Patents

Description

Method for forming a molecularly-printed polymer film on a plastic substrate

The invention relates to a method for forming a molecularly-printed polymer film on a substrate, in particular to a method for forming a molecularly-printed polymer film for detecting a small molecule anesthetic on a plastic substrate.

Molecular imprinted polymer film (hereinafter referred to as "MIP film") has a wide range of applications, such as separation, extraction, artificial antibodies, catalysts, and Biosensor, etc. At present, the MIP film is mainly prepared by "a target molecule" having a structure similar to a target molecule (especially a structure size and a functional group contained therein), and "functional monomer" (functional monomer) ""," "crosslinking agent" and "initiator" are mixed to form a mixture, and then the mixture is applied to a substrate, followed by polymerization and curing reaction. A cured film is formed on the substrate, and finally the cured film is extracted with a solvent capable of dissolving the template molecule to obtain the MIP film.

US 5,587,273 discloses a method for molecularly extruding a material comprising: (1) forming a solution containing a solvent, a polymer capable of undergoing addition reaction with nitrene, a crosslinking agent a functional monomer and a template molecule; (2) evaporating the solution to obtain a residue; (3) exposing the residue to an energy source to thereby form a crosslinked polymer film; And (4) extracting the crosslinked polymer film to remove the template molecule and obtain a MIP film. This patent does not provide an in-depth study of the properties of the MIP film produced [such as adsorption specificity and linearity or sensitivity of subsequent applications].

In the various preparation methods of the existing MIP film, in order to effectively improve the adsorption specificity of the MIP film, it is necessary to make the MIP film have a plurality of holes to increase the contact area of the target molecules, and the size of the holes is only allowed to be optimal. Allowing the target molecule to enter, it helps to improve the adsorption specificity of the MIP film. At present, most of the ways of adding holes are to grind the MIP film, or to add a hole adjusting agent when preparing the MIP film. However, the above method easily causes the identification structure of the MIP film to be damaged. It can be seen that the preparation method of the existing MIP film still needs to be improved.

Therefore, the object of the present invention is to provide a method for forming a molecularly-printed polymer film on a plastic substrate, which can make the molecularly-printed polymer film have a suitable pore size and anesthesia at different concentrations. Different adsorption specificities can be exhibited in the drug, and the subsequent sensitivity and linearity can be exhibited when applied to the microfluidic wafer and tested.

Thus, the method of the present invention for forming a molecularly imprinted polymeric film on a plastic substrate comprises the steps of: (a) applying a reaction mixture to the plastic substrate, wherein the reaction mixture contains a template molecule a small molecule anesthetic, a functional monomer, an initiator, and a crosslinking agent, the functional monomer having at least one functional group capable of binding to the small molecule anesthetic, the small molecule anesthetic: the functional single Body: the crosslinking agent: the molar ratio of the starting agent ranges from 1:4:30:0.17 to 1:4:30:0.85; (b) the reaction is carried out under a light source having a specific range of exposure energy The mixture is exposed to form a cured film on the plastic substrate; and (c) removing the small molecule anesthetic on the cured film to form the molecularly-printed polymer film on the plastic substrate.

The method for forming a molecularly-printed polymer film on a plastic substrate can make the prepared molecularly-printed polymer film have a comparative advantage by using an initiator of a specific molar ratio range and a specific range of exposure energy. The size of the pores is suitable to enhance the adsorption specificity.

Referring to FIG. 1, a preferred embodiment of the method for forming a molecularly-printed polymer film on a plastic substrate comprises: (a) applying a reaction mixture 2 to a plastic substrate 1 [eg Figure 1 (a)], wherein the reaction mixture 2 contains a small molecule anesthetic as a template molecule, a functional monomer, a starter and a crosslinking agent, the functional monomer having at least one capable of The small molecule anesthetic produces a bonded functional group, the small molecule anesthetic: the functional monomer: the crosslinking agent: the molar ratio of the starting agent ranges from 1:4:30:0.17 to 1:4:30: 0.85; (b) exposing the reaction mixture 2 under a light source having a specific range of exposure energy [Fig. 1 (b)] to form a cured film 3 on the plastic substrate 1; and (c The small molecule anesthetic agent 31 on the cured film 3 is removed [Fig. 1 (c)] to form a molecularly-printed polymer film 4 on the plastic substrate 1.

In addition to improving solvent resistance, the plastic substrate 1 of the step (a) can greatly reduce the manufacturing cost and facilitate subsequent use. Preferably, the plastic substrate 1 has better chemical resistance, better physical properties, and high light transmittance, for example, a substrate composed of a cyclic olefin copolymer (COC).

Small molecule anesthetics are generally referred to as liquid anesthetics. Preferably, the small molecule anesthetic is 2,6-dipropofol (propofol).

The functional monomer has at least one functional group capable of binding to a small molecule anesthetic. Preferably, the functional monomer is methacrylic acid.

The crosslinking agent may include, but is not limited to, ethylene glycol dimethacrylate (EGDMA) and divinylbenzene (DVB).

The initiator may include, but is not limited to, 2,2'-azobisisobutyronitrile (AIBN) and 1,1'-azobiscyclohexanecarbonitrile (1,1'-azobiscyclohexanecarbonitrile, ABCN). In one embodiment of the invention, the initiator is AIBN.

The small molecule anesthetic: the functional monomer: the crosslinking agent: the molar ratio of the starting agent ranges from 1:4:30:0.17 to 1:4:30:0.85. Preferably, the molar ratio ranges from 1:4:30:0.30 to 1:4:30:0.50. In one embodiment of the invention, the molar ratio is 1:4:30:0.41. When the molar ratio of the initiator is less than 0.17, the film will not be completely cured; when the molar ratio of the initiator is greater than 0.85, the film will be cracked or crystal-like, thereby affecting the penetration of the film. Luminosity.

It should be noted that the reaction mixture does not contain toluene or a pore regulator.

Preferably, the step (b) the exposure energy in the range of ^{16J / cm 2 ~ 72J / cm} 2.

Preferably, in step (b), the reaction mixture 2 is exposed to a mask having a specific pattern. The pattern of the reticle can be adjusted and varied as needed. When a photomask having a plurality of hole patterns is used, after the exposure curing, since only the reaction mixture 2 under the hole pattern is cured, the formed cured film 3 will be composed of a plurality of cured film units, whereby A MIP film 4 composed of a plurality of MIP film units is produced in one process.

The removal method of the step (c) can be carried out according to a conventional manner. Preferably, the step (c) is to clean the cured film 3 with a reagent to complete the removal of the small molecule anesthetic 31. The reagent is preferably methanol.

Preferably, the molecularly-printed polymer film 4 of the step (c) has a thickness ranging from 25 to 75 μm.

Preferably, the molecularly-printed polymer film 4 of the step (c) has a plurality of holes having a diameter ranging from 10 to 30 nm.

The method of the invention can form a hole having a plurality of pore diameters on the substrate without grinding or adding a hole adjusting agent, thereby effectively improving the adsorption specificity of the MIP film.

Referring to FIG. 2, the plastic substrate 1 containing the MIP film 4 prepared by the present invention can be directly subjected to thermocompression bonding with a plastic substrate 7 having a micro-fluid channel structure to obtain a microfluid. Micro-fluid chip. The prepared microfluidic wafer will have good sensitivity, linearity and the like when performing sensing. In addition, it is worth mentioning that, in the production of the microfluidic wafer, since the plastic substrate 1 containing the MIP film 4 and the plastic substrate 7 having the micro flow channel structure are made of plastic material, it is not necessary to use an adhesive. Join directly using hot pressing.

The present invention will be further illustrated by the following examples, but it should be understood that this embodiment is intended to be illustrative only and not to be construed as limiting.

<Example>

[Example 1]

Referring to FIG. 3, two substrates 1 (all made of a cyclic olefin copolymer) are sandwiched between two polyimide shims 5 having a thickness of 25 μm to jointly define an accommodating space. A reaction mixture 2 was prepared according to a small molecule anesthetic (propofol): functional monomer (methacrylic acid): cross-linking agent (EGDMA): starting agent (ABCN) in a molar ratio of 1:4:30:0.41. The reaction mixture 2 was filled into the accommodating space [shown in step (a) of Fig. 3]. Next, using a UV exposure system (UV exposure system, ultraviolet light wavelength of 365 nm, exposure power of 20 mW / cm ² , exposure time of 2000 seconds, that is, exposure energy of 40 J / cm ² ), as shown in Figure 4 Under the mask 6 of the specific pattern, the reaction mixture 2 is photocured to form a cured film 3 composed of a plurality of cured film units on the substrate 1 [step (b) of FIG. 3 Show]. The cured film 3 is immersed in methanol [as shown in step (c) of FIG. 3], and after 24 hours, the small molecule anesthetic agent 31 is removed, and a plurality of MIP film units having a specific pattern are formed. The MIP film 4 is constructed.

[Examples 2 to 10]

The process of the MIP film of Examples 2 to 10 was substantially the same as that of Example 1 except that the thickness of the polyimide film 5 and the exposure time were changed according to the following Table 1. Finally, the MIP films of Examples 2 to 10 were respectively obtained.

[Example 11]

The process of the MIP film of Example 11 was substantially the same as that of Example 1, except that the molar ratio of the small molecule anesthetic: functional monomer: crosslinking agent: initiator was changed to 1:4:30:0.17. The MIP film of Example 11 was obtained, respectively.

[Test] The MIP films of Examples 1 to 10 (labeled Ex1 to Ex10 in Tables 2 and 3) were subjected to the following tests:

1. Appearance observation of the cured film 3: The appearance of the cured film 3 formed in the step (b) was observed in the preparation process of Example 1 by a scanning electron microscope, and the results obtained are shown in Fig. 5.

2. Appearance observation of MIP film 4: The MIP film 4 formed in Example 1 and Example 3 was observed by a scanning electron microscope, and the results obtained are shown in Figures 6(a) and (b), wherein Figure 6 ( a) is the result of Example 1, and Figure 6(b) is the result of Example 3.

3. Transmittance (%): The MIP films of Examples 2 to 10 were taken out separately, and the following transmittance tests were carried out separately - the MIP film was sandwiched between two quartz wafers, and then irradiated with an ultraviolet spectrometer. Photometric test, the results obtained are summarized in Table 2 below. The higher the transmittance, the better.

4. Reduction rate (%): The MIP films of Examples 2 to 10 were taken out separately, and the following transmittance tests were carried out separately - the MIP film was sandwiched between two polyolefin copolymer substrates, and captured by a digital camera. After the photo, the area is measured by ImageJ image program (developed by National Institutes of Health, USA), and the reduction rate is calculated by the following formula: (MIP film area / area of each unit pattern of the mask) × 100%, The results obtained are summarized in Table 2 below. The reduction rate is expected to be higher and better.

5. Expansion ratio (%): The MIP films of Examples 2 to 10 were taken out separately, and the following expansion ratio tests were respectively carried out - the MIP film was immersed in methanol to obtain a completely wet MIP film, and the above reduction rate was utilized. The test procedure was carried out, and finally, the expansion ratio was calculated by the following formula: (MIP film area after complete wetting/MIP film area obtained by the above reduction rate test) × 100%, and the results are summarized in Table 2 below. The reduction rate is expected to be higher and better.

6. Adsorption amount (μg/mm ² ): An appropriate amount of propofol was dissolved in methanol to obtain a propofol solution having a concentration of 0.7918, 7.918, and 19.795 μg/mL. The adsorption amounts of the MIP films of Examples 1 and 3 at the above three different concentrations were tested as follows: The MIP film was placed in a 2 g propofol solution, and after 15 minutes of adsorption, the concentration of the Propofol solution was measured and then passed through. The following formula calculates the amount of adsorption, and the results are summarized in Table 3:

Adsorption amount (μg/mm ² ) = [(origin concentration of propofol solution - concentration after adsorption of propofol solution) × 2] / area of MIP film

7. Specific binding rate (%): The cured films prepared in the steps (b) of Examples 1 and 3 were respectively tested according to the above-mentioned adsorption amount test method, and the specific binding ratios were calculated according to the following formulas, respectively. In Table 3:

Specific binding rate (%) = (adsorption amount of MIP film / adsorption amount of cured film of step (b)) × 100%

In Figure 5, Example 1 provides a fully cured film. It is thus proved that the molar ratio of the initiator affects the degree of curing of the film, so that the molar ratio of the initiator is particularly controlled.

In Fig. 6(a), the MIP film of Example 1 was found to have a plurality of holes, and the hole diameter was about 10 to 25 nm. In Fig. 6(b), the MIP film of Example 3 also has a plurality of holes, and the hole diameter is about 13.8 nm. From the above results, it can be confirmed that the method of the present invention can make the MIP film have a plurality of holes, and the hole diameter (about 10 to 25 nm) can be effectively reduced.

In Table 2, it can be found that the MIP films of Examples 2 to 10 have transmittance, reduction rate, and expansion ratio in line with industry requirements.

It can be seen from the results of Table 3 that Examples 1 and 3 have different adsorption amounts (0.00098-0.05521 μg/mm ² ) and specific binding rates (164.84% to 455.82%) under different concentrations of propofol solution, respectively, demonstrating the method of the present invention. The formed MIP film exhibits different adsorption amounts and specific binding rates in different concentrations of small molecule anesthetic solutions, and is shown to be suitable for detecting small molecule anesthetics, and when subsequently fabricated into a microfluidic wafer and applied to the detection of anesthetic agents, It also shows the advantages of sensitivity and linearity.

In summary, the method for forming a molecularly-printed polymer film on a plastic substrate can form a suitable hole on the substrate by using a specific proportion of the initiator and a specific range of exposure energy. Molecularly-printed polymer film of diameter.

The above is only the preferred embodiment of the present invention, and the scope of the invention is not limited thereto, that is, the simple equivalent changes and modifications made by the scope of the invention and the description of the invention are All remain within the scope of the invention patent.

1. . . Plastic substrate

2. . . Reaction mixture

3. . . Cured film

31. . . Small molecule anesthetic

4. . . Molecularly-printed polymer film

5. . . Polyimide gasket

6. . . Mask

7. . . Plastic substrate with microchannel structure

1 is a schematic flow chart showing a continuous step of a preferred embodiment of the method for forming a molecularly imprinted polymer film on a plastic substrate;

2 is a schematic flow chart showing the steps of preparing a substrate containing a molecularly-printed polymer film prepared by the method of the present invention into a microfluidic wafer;

3 is a schematic flow chart showing a continuous step of an embodiment of the method for forming a molecularly imprinted polymer film on a plastic substrate;

Figure 4 is a plan view showing an aspect of the reticle used in the step (b) of the method of the present invention;

Figure 5 is an electron micrograph showing the curing of the reaction mixture of Example 1;

6(a) and 6(b) are electron micrographs showing the appearance of the MIP films of Examples 1 and 3, wherein Fig. 6(a) shows the results of Example 1 and Fig. 6(b) shows the results of Example 3. .

1. . . Plastic substrate

2. . . Reaction mixture

3. . . Cured film

31. . . Small molecule anesthetic

4. . . Molecularly-printed polymer film

Claims (5)

A method for forming a molecularly imprinted polymer film on a plastic substrate, comprising the steps of: (a) applying a reaction mixture to the plastic substrate, wherein the reaction mixture contains a template molecule 2,6-dipropofol, a functional monomer, a starter and a crosslinking agent, the functional monomer having at least one functional group capable of binding to the 2,6-dipropofol, The 2,6-dipropofol: the functional monomer: the crosslinking agent: the molar ratio of the starting agent ranges from 1:4:30:0.17 to 1:4:30:0.85; (b) The reaction mixture is exposed to light to form a cured film on the plastic substrate under a light source having an exposure energy range of 16 J/cm ² to 72 J/cm ² ; and (c) removing the cured film , 6-dipropofol, to form a molecularly imprinted polymer film on the plastic substrate. The method of claim 1, wherein the substrate of the step (a) is composed of a cyclic olefin copolymer. The method of claim 1, wherein in the step (b), the reaction mixture is exposed to a mask having a specific pattern. The method according to claim 1, wherein the molecularly-printed polymer film obtained in the step (c) has a thickness ranging from 25 to 75 μm. The method according to claim 1, wherein the molecularly-printed polymer film obtained in the step (c) has a plurality of diameter ranges 10~30nm holes.