阅读说明：本技术 胰蛋白酶检测薄膜及其制备方法、应用和胰蛋白酶检测试剂盒 (Trypsin detection film, preparation method and application thereof and trypsin detection kit ) 是由 张书鹏 段晓东 于 2020-07-24 设计创作，主要内容包括：本发明提供了一种胰蛋白酶检测薄膜及其制备方法、应用和胰蛋白酶检测试剂盒,涉及胰蛋白酶检测技术领域。该胰蛋白酶检测薄膜的制备方法,包括以下步骤：提供聚合物薄膜基材；将所述聚合物薄膜基材浸没于染料中,使染料附着于聚合物薄膜基材,得到胰蛋白酶检测薄膜。本发明的制备方法操作简单,成本低,技术门槛低,对检测和操作人员要求低,本发明能够缓解现有技术中胰蛋白酶检测存在的技术难度大、测试复杂、高成本等问题。(The invention provides a trypsin detection film, a preparation method and application thereof, and a trypsin detection kit, and relates to the technical field of trypsin detection. The preparation method of the trypsin detection film comprises the following steps: providing a polymeric film substrate; and immersing the polymer film substrate into the dye to attach the dye to the polymer film substrate to obtain the trypsin detection film. The preparation method disclosed by the invention is simple to operate, low in cost, low in technical threshold and low in requirements on detection and operating personnel, and can be used for relieving the problems of high technical difficulty, complex test, high cost and the like in trypsin detection in the prior art.)

1. A preparation method of a trypsin detection film for trypsin detection is characterized by comprising the following steps:

providing a polymeric film substrate;

immersing the polymer film substrate in a dye to enable the dye to be attached to the polymer film substrate, so as to obtain a trypsin detection film;

wherein the dye is adapted to interact with trypsin, the dye differing in color in environments with differing concentrations of trypsin; the dye comprises at least one of bromocresol purple dye, 3',5,5' -tetramethyl benzidine dye, triarylmethane dye, xylenol orange dye or metal complex dye.

2. The method for preparing a trypsin detection film according to claim 1, wherein the concentration of the dye is 0.25 to 2.5mg/mL, preferably 1 to 2 mg/mL;

preferably, the solvent of the dye comprises water and/or an alcohol solvent;

preferably, the temperature for immersing the polymer film substrate in the dye is 20-40 ℃, preferably 25-35 ℃, and the time for immersing the polymer film substrate in the dye is 15-30 min, preferably 18-22 min.

3. The method of preparing a trypsin detection film according to claim 1, wherein the method of preparing a polymer film substrate comprises the steps of:

providing a substrate assembly comprising a substrate and a first lubricant disposed on the substrate;

placing the film-forming solution of the polymer film substrate on the substrate assembly, and covering a cover plate with a second lubricant on the film-forming solution, wherein the film-forming solution is in contact with the first lubricant and the second lubricant respectively;

after the polymerization reaction of the raw materials in the film-forming solution, separating the polymer film substrate from the substrate assembly and the cover plate to obtain the polymer film substrate;

preferably, the substrate assembly further comprises tinfoil, the tinfoil being disposed on the substrate, the first lubricant being disposed on the tinfoil.

4. The method of preparing a trypsin detection film according to claim 3, wherein the first lubricant and the second lubricant are each independently selected from at least one of white petrolatum, silicone oil, paraffin wax, mineral oil, or grease.

5. The method for preparing a trypsin detection film according to claim 3, wherein the polymerization reaction is performed under irradiation of ultraviolet light; the wavelength of the ultraviolet light is preferably 250-400 nm; and/or the time of ultraviolet irradiation is preferably 10-30 min;

preferably, after the ultraviolet light irradiation, the curing box is placed for 5-10 min.

6. The method of claim 3, wherein separating the polymer film substrate from the substrate assembly and the cover plate comprises: removing the substrate assembly, placing the cover plate attached with the polymer film substrate in a standing solution, standing for 10-30 min, and removing the cover plate to obtain the polymer film substrate; or removing the cover plate, placing the substrate assembly attached with the polymer film substrate in a solution, standing for 10-30 min, and removing the substrate assembly to obtain the polymer film substrate;

preferably, removing the substrate, placing the cover plate and the tinfoil attached with the polymer film base material in a standing solution, standing for 10-30 min, and removing the tinfoil to obtain the polymer film base material;

preferably, after separating the polymer film substrate from the substrate assembly and the cover plate, the method further comprises a step of cleaning the polymer film substrate, wherein the cleaning comprises sequentially performing ultrasonic cleaning in clean water, an alcohol solution and clean water.

7. The method for preparing a trypsin detection film according to any one of claims 3 to 6, wherein the method for preparing the deposition solution comprises:

uniformly mixing an ionic liquid monomer and a base membrane monomer, adding a cross-linking agent and an initiator, and then carrying out second ultrasonic treatment to obtain the film forming solution;

preferably, the time of the second ultrasonic treatment is 10-30 min;

preferably, the method for preparing the film-forming solution further comprises the step of carrying out first ultrasonic treatment on the ionic liquid monomer, wherein the time of the first ultrasonic treatment is 10-30 min;

preferably, the film-forming solution comprises at least one of imidazole ionic liquid, pyridine ionic liquid, quaternary ammonium salt ionic liquid, quaternary phosphine ionic liquid or pyrrolidine ionic liquid;

preferably, the ionic liquid monomers include bromobutane and vinylimidazole; preferably, the molar ratio of bromobutane to vinylimidazole is from 2:1 to 1: 1;

preferably, the base film monomer includes acrylonitrile; preferably, the mass of acrylonitrile is greater than or equal to the sum of the masses of bromobutane and vinylimidazole;

preferably, the crosslinking agent comprises N, N-methylene bisacrylamide; preferably, the mass of the cross-linking agent is 8-12 wt% calculated by the total mass of bromobutane, vinyl imidazole and acrylonitrile;

preferably, the initiator comprises 2,4,6- (trimethylbenzoyl) diphenylphosphine oxide; preferably, the mass of the initiator is 1 wt% to 4 wt% calculated on the total mass of bromobutane, vinylimidazole and acrylonitrile.

8. A trypsin detection film prepared by the method for preparing a trypsin detection film according to any one of claims 1 to 7.

9. The detection film prepared by the method for preparing a trypsin detection film according to any one of claims 1 to 7 or the use of the trypsin detection film according to claim 8 in the detection of trypsin, wherein the detection method comprises:

and placing the trypsin detection film in a solution to be detected, and enabling the dye in the trypsin detection film to contact or interact with the solution to be detected.

10. The use according to claim 9, wherein the detection method further comprises: the trypsin detection film was observed for color change.

11. The use according to claim 9, wherein the detection method further comprises: and in the environment containing the liquid to be detected with different trypsin concentrations, the colors of the trypsin detection films are different, and the trypsin concentration is judged according to the different colors displayed by the trypsin detection films.

12. A trypsin detection kit comprising the detection film prepared by the method for preparing a trypsin detection film according to any one of claims 1 to 7 or the trypsin detection film according to claim 8.

13. The trypsin detection kit of claim 12, further comprising a trypsin detection standard color chart.

Technical Field

The invention relates to the technical field of trypsin detection, and particularly relates to a trypsin detection film, a preparation method and application thereof, and a trypsin detection kit.

Background

Trypsin is a component of pancreatic juice, an important protein digestive enzyme, and can limit and decompose chymotrypsinogen, procarboxypeptidase, prophalase and other enzyme precursors for activation. Trypsin is the most specific protease, capable of cleaving the hydroxyl side of lysine and arginine residues in polypeptide chains, and is one of the most important digestive enzymes in proteolysis. In clinical detection, treatment and research, the content of trypsin is also an important marker for clinical diagnosis of pancreas-related diseases, and the secretion, activation, inhibition and circulation imbalance of trypsin can cause acute or chronic pancreatic diseases, such as pancreatic cancer. The detection of trypsin plays an important role in the fields of human health, production quality control and the like. Therefore, the detection of trypsin is particularly important.

The traditional method for detecting the content of the trypsin is mainly a spectrophotometry, but the method has more steps for detecting the trypsin, complicated operation and lower detection sensitivity. The methods developed at present mainly include ultraviolet spectrophotometry, colorimetry, fluorescence, immunoassay, radioactive element labeling, Mass Spectrometry (MS), liquid chromatography (HPLC), electrophoresis, and the like. Wherein, the ultraviolet method and the colorimetric method have simple operation, low sensitivity and poor reproducibility. The immunoassay method has high sensitivity, but the use of monoclonal antibodies also increases the cost, and requires a certain operation technique, which makes the popularization difficult. The radioactive element labeling method needs to label a substrate, is complex to prepare and has certain safety problems and the like. Mass spectrometry instruments in mass spectrometry are expensive, and the requirement on the purity of a sample is high; chromatography and electrophoresis also require relatively complicated procedures and long detection times.

Disclosure of Invention

The invention aims to provide a trypsin detection film, a preparation method and application thereof, and a trypsin detection kit, which have the advantages of easiness in operation, short time, low cost, low technical threshold and the like, and can overcome the problems or at least partially solve the technical problems.

In order to achieve the purpose, the technical scheme adopted by the application is as follows:

according to one aspect of the present application, there is provided a method for preparing a trypsin detection film, comprising the steps of:

providing a polymeric film substrate;

and immersing the polymer film substrate into the dye to attach the dye to the polymer film substrate to obtain the trypsin detection film.

Wherein the dye is adapted to interact with trypsin, the dye differing in color in environments with differing concentrations of trypsin; the dye comprises at least one of bromocresol purple dye, 3',5,5' -tetramethyl benzidine dye, triarylmethane dye, xylenol orange dye or metal complex dye.

In one possible implementation mode, the concentration of the dye is 0.25-2.5 mg/mL, preferably 1-2 mg/mL;

preferably, the solvent of the dye comprises water and/or an alcohol solvent;

preferably, the temperature for immersing the polymer film substrate in the dye is 20-40 ℃, preferably 25-35 ℃; and/or immersing the polymer film substrate in the dye for 15-30 min, preferably 18-22 min.

In one possible implementation, the method for preparing the polymer film substrate comprises the following steps:

providing a substrate assembly comprising a substrate and a first lubricant disposed on the substrate;

placing the film-forming solution of the polymer film substrate on the substrate assembly, and covering a cover plate with a second lubricant on the film-forming solution, wherein the film-forming solution is in contact with the first lubricant and the second lubricant respectively;

after the polymerization reaction of the raw materials in the film-forming solution, separating the polymer film substrate from the substrate assembly and the cover plate to obtain the polymer film substrate;

preferably, the substrate assembly further comprises tinfoil, the tinfoil being disposed on the substrate, the first lubricant being disposed on the tinfoil.

In one possible implementation, the first lubricant and the second lubricant are each independently selected from at least one of white petrolatum, silicone oil, paraffin wax, mineral oil, or grease.

In one possible implementation, the polymerization reaction is carried out under irradiation of ultraviolet light; wherein the wavelength of the ultraviolet light is preferably 250-400 nm; and/or the time of ultraviolet irradiation is preferably 10-30 min;

preferably, after the ultraviolet light irradiation, the curing box is placed for 5-10 min.

In one possible implementation, the separating the polymer film substrate from the substrate assembly and the cover plate includes: removing the substrate assembly, placing the cover plate attached with the polymer film substrate in a standing solution, standing for 10-30 min, and removing the cover plate to obtain the polymer film substrate; or removing the cover plate, placing the substrate assembly attached with the polymer film substrate in a solution, standing for 10-30 min, and removing the substrate assembly to obtain the polymer film substrate;

preferably, removing the substrate, placing the cover plate and the tinfoil attached with the polymer film base material in a standing solution, standing for 10-30 min, and removing the tinfoil to obtain the polymer film base material;

preferably, after separating the polymer film substrate from the substrate assembly and the cover plate, the method further comprises a step of cleaning the polymer film substrate, wherein the cleaning comprises sequentially performing ultrasonic cleaning in clean water, an alcohol solution and clean water.

In one possible implementation, the method for preparing the deposition solution comprises:

uniformly mixing an ionic liquid monomer and a base membrane monomer, adding a cross-linking agent and an initiator, and then carrying out second ultrasonic treatment to obtain the film forming solution;

preferably, the time of the second ultrasonic treatment is 10-30 min;

preferably, the method for preparing the film-forming solution further comprises the step of carrying out first ultrasonic treatment on the ionic liquid monomer, wherein the time of the first ultrasonic treatment is 10-30 min;

preferably, the film-forming solution comprises at least one of imidazole ionic liquid, pyridine ionic liquid, quaternary ammonium salt ionic liquid, quaternary phosphine ionic liquid or pyrrolidine ionic liquid;

preferably, the ionic liquid monomers include bromobutane and vinylimidazole; preferably, the molar ratio of bromobutane to vinylimidazole is from 2:1 to 1: 1;

preferably, the base film monomer includes acrylonitrile; preferably, the mass of acrylonitrile is greater than or equal to the sum of the masses of bromobutane and vinylimidazole;

preferably, the crosslinking agent comprises N, N-methylene bisacrylamide; preferably, the mass of the cross-linking agent is 8-12 wt% calculated by the total mass of bromobutane, vinyl imidazole and acrylonitrile;

preferably, the initiator comprises 2,4,6- (trimethylbenzoyl) diphenylphosphine oxide; preferably, the mass of the initiator is 1 wt% to 4 wt% calculated on the total mass of bromobutane, vinylimidazole and acrylonitrile.

According to another aspect of the present application, there is provided a trypsin detection film prepared by the above-described method for preparing a trypsin detection film.

According to another aspect of the present application, there is provided a detection film prepared by the method for preparing a trypsin detection film or an application of the trypsin detection film in detecting trypsin, wherein the detection method comprises:

and placing the trypsin detection film in a solution to be detected, and enabling the dye in the trypsin detection film to contact or interact with the solution to be detected.

In one possible implementation manner, the detection method further includes: the trypsin detection film was observed for color change.

In one possible implementation manner, the detection method further includes: and in the environment containing the liquid to be detected with different trypsin concentrations, the colors of the trypsin detection films are different, and the trypsin concentration is judged according to the different colors displayed by the trypsin detection films.

According to another aspect of the present application, the present application further provides a trypsin detection kit comprising the detection film prepared by the above-described trypsin detection film preparation method or the trypsin detection film described above.

In one possible implementation mode, the trypsin detection kit further comprises a trypsin detection standard colorimetric card.

Compared with the prior art, the technical scheme provided by the invention can achieve the following beneficial effects.

The preparation method of the trypsin detection film provided by the invention has the characteristics of simple synthesis, short preparation period, easiness in operation, low cost, low technical threshold and the like, and is easy to realize large-scale production and use. Moreover, the trypsin detection film prepared by the method can be applied to trypsin detection in a large scale, so that the problems of great technical difficulty, long detection time, high cost and incapability of meeting the current requirements of the existing trypsin detection mode are solved.

The trypsin detection kit of the invention has all the characteristics and advantages of the trypsin detection film, and is not described in detail herein.

It is to be understood that both the foregoing general description and the following detailed description are exemplary and explanatory only and are not restrictive of the invention, as claimed.

Drawings

In order to more clearly illustrate the detailed description of the invention or the technical solutions in the prior art, the drawings that are needed in the detailed description of the invention or the prior art will be briefly described below.

FIG. 1 is a table showing the RGB color value contrast relationship of a trypsin detection film according to one embodiment of the present invention.

Detailed Description

In order to make the purpose, technical solutions and advantages of the present application clearer, the technical solutions of the present application will be clearly and completely described below with reference to the embodiments of the present application, and it should be apparent that the described embodiments are some but not all of the embodiments of the present application. All other embodiments obtained by those skilled in the art without any creative effort based on the technical solutions and the given embodiments provided in the present application belong to the protection scope of the present application. The examples, in which specific conditions are not specified, were conducted under conventional conditions or conditions recommended by the manufacturer.

It should be noted that the term "and/or"/"used herein is only one kind of association relationship describing associated objects, and means that there may be three relationships, for example, a and/or B, and may mean: a exists alone, A and B exist simultaneously, and B exists alone. As used in the examples of this application and the appended claims, the singular forms "a", "an", and "the" are intended to include the plural forms as well, unless the context clearly indicates otherwise.

The endpoints of the ranges and any values disclosed herein are not limited to the precise range or value, and such ranges or values should be understood to encompass values close to those ranges or values. For numerical ranges, one or more new numerical ranges may be obtained by combining the individual values, or by combining the individual values.

All the technical features mentioned herein, as well as preferred features, may be combined with each other to form new solutions, if not mentioned specifically. Unless defined or indicated otherwise, technical and scientific terms used herein have the same meaning as is familiar to those skilled in the art.

As mentioned in the background, the existing trypsin detection methods have some disadvantages. For example, the prior art discloses a biosensor for detecting trypsin, a preparation method thereof and an application thereof in detecting trypsin, the biosensor comprises a magnetic gold electrode, magnetic nanoparticles, polypeptide chains 1 and polypeptide chains 2, the surfaces of the magnetic nanoparticles are modified with carboxyl groups, the surfaces of the polypeptide chains 2 are loaded with silver nanoparticles, one terminal sequence of each of the polypeptide chains 1 and 2 is VIA, and the polypeptide chains 1 contain arginine residues; the surface of the detection end of the magnetic gold electrode adsorbs the magnetic nanoparticles through magnetism, the polypeptide chain 1 is fixed on the magnetic nanoparticles through the reaction of the amino at the tail end and the carboxyl modified on the surface of the magnetic nanoparticles, and the polypeptide chain 2 is self-assembled on the polypeptide chain 1 through a tail end sequence VIA. Although the sensor and the method can realize the detection of trypsin, the process is complicated, the preparation is difficult, and the interference is easy. For another example, the prior art discloses a fluorescent probe for trypsin detection and a preparation method thereof, the fluorescent probe is a compound aqueous solution composed of a fluorescent labeling polymer and cytochrome C adsorbed on the surface of the fluorescent labeling polymer, the weight percentage concentration of the compound aqueous solution is 0.0005% -0.05%, the hydrophobic dye pyrene is modified by a hydrophilic polymer, the obtained water-soluble fluorescent labeling polymer is used as an energy donor for fluorescence emission, the cytochrome C is used as a substrate of trypsin, the fluorescent probe for trypsin detection is obtained by adsorbing the cytochrome C on the surface of the fluorescent labeling polymer, and the detection of the enzyme activity is realized by the change of the fluorescence intensity. Although the probe can realize the detection of trypsin, the process is complicated, the adsorption rate is low, the preparation is difficult, the anti-interference performance is weak, the fluorescence is easy to quench, and meanwhile, the detection of the fluorescence intensity needs special equipment. For another example, the prior art discloses a colorimetric analysis method for rapidly determining trypsin, which comprises the steps of firstly detecting UV-Vi s (ultraviolet-visible spectrum) of silver nanoparticles, then carrying out a color reaction on the trypsin and polypeptide modified silver nanoparticles, detecting the ultraviolet spectrum of a reaction product after the color reaction is finished, and then comparing the difference value with a preset standard curve by calculating the difference value of the light absorption value peak values of the silver nanoparticles and the reaction product so as to obtain the content of the trypsin. The detection method has higher sensitivity and lower detection limit, does not need to carry out complicated chemical modification or signal marking, but has higher requirement on detection personnel, needs special equipment, is easy to oxidize silver nanoparticles and is difficult to store.

Therefore, in view of the existing trypsin detection methods, the methods have the disadvantages of great technical difficulty, complex test, high cost, single function, incapability of meeting the current requirements and the like. The technical scheme of the embodiment of the invention provides a trypsin detection film, a preparation method and application thereof and a trypsin detection kit. The invention prepares the trypsin detection film by a simple and efficient preparation method, and has the advantages of simple and convenient synthesis, short preparation period, low technical threshold, reusability and the like.

In a first aspect, in some embodiments, there is provided a method of making a trypsin detection film, comprising the steps of:

providing a polymeric film substrate;

immersing the polymer film substrate in a dye to attach the dye to the polymer film substrate to obtain a trypsin detection film;

wherein the dye is adapted to interact with trypsin, the dye being of a different color in environments with different concentrations of trypsin; the dye includes, but is not limited to, at least one of bromocresol purple dye, 3',5,5' -tetramethylbenzidine dye, triarylmethane-based dye, xylenol orange dye, or metal complex-based dye.

The method has the advantages of simple preparation, easy operation, low cost and easy large-scale production and use.

Specifically, the preparation method of the trypsin detection film is a simple, convenient and efficient preparation method, and has the advantages of simple preparation, easy operation, low technical threshold, low cost, low requirements on detection and operation personnel, easy large-scale production and use and the like. The trypsin detection film prepared by the method can be applied to trypsin detection, has the advantages of simplicity and convenience in operation, low cost, safety and the like, and can judge the concentration of trypsin according to color, so that the trypsin detection film has great application potential.

In the trypsin detection film, the polymer film substrate can be a polyion film, namely a polyion liquid type film, the polymer film has the excellent performances of both the ionic liquid and the polymer, can overcome the fluidity of the ionic liquid, has unique physicochemical properties, and can be well applied to the field of medical detection.

In the trypsin detection film, the dye is a compound which has a certain color and can make other substances obtain bright or more obvious colors. In the examples of the present application, the dye detects that trypsin can change color and the dye and the polymer film substrate can form a good stable fit. Specifically, the polymer film substrate can adsorb the dye, or the dye can be well attached to the polymer film substrate, and the dye can be well kept on the polymer film substrate due to the strong ionic interaction between the two.

Compared with the prior art, the embodiment of the application utilizes the combination of the dye and the trypsin or the reaction (interaction) to develop the color, and has the advantages of simple operation, low technical threshold, obvious color development change, low cost, quick detection and the like.

Specifically, the specific shape of the trypsin detection film may be various types, for example, any shape such as a circle, a square, a polygon, or other irregular shape, or may be a sheet, a strip, or the like, and the specific shape of the trypsin detection film is not limited in the embodiments of the present application.

Specifically, the size of the trypsin detection film may be adjusted according to the actual situation, and the specific size of the trypsin detection film is not limited in the examples of the present application.

In particular, the dye is adapted to interact with trypsin, the color of the dye being different in environments with different concentrations of trypsin. That is, the dye has different colors when the trypsin concentration is different. Thus, the interaction between the dye and trypsin is used for developing color, and the color change of the trypsin detection film is observed, so that the detection result can be obtained. In addition, different color development effects can be achieved by dye mixing or changing the concentration of the dye.

Specifically, the dye includes, but is not limited to, at least one of bromocresol purple dye, 3',5,5' -tetramethylbenzidine dye, triarylmethane-based dye, xylenol orange dye, or metal complex-based dye.

It should be noted that the dye may be bromocresol purple dye, or 3,3',5,5' -tetramethylbenzidine dye, or xylenol orange dye, or triarylmethane dye, or metal complex dye, or a mixture of the above dyes, but is not limited thereto. More generally, the dye may be any dye that satisfies the following three conditions: (1) can be stably combined with a polymer film substrate; (2) capable of binding to or interacting with trypsin; (3) meets the requirement of biological safety.

The bromocresol purple dye is taken as an example, belongs to a biological stain and is safe and nontoxic, the bromocresol purple dye can be combined with trypsin through a non-covalent bond, and a hydrophobic core of the trypsin is combined with a nonpolar group of the bromocresol purple dye. And the volume of the combined aggregate is larger than that of the bromocresol purple dye, so that the molar absorption coefficient after combination is changed, the light scattering signal is changed, and different colors are displayed. And since the signal intensity is proportional to the number of particles per unit volume, i.e., the concentration of trypsin, the detection of the concentration of trypsin can be achieved by observing the color. In the detection process, the bromocresol purple dye in the trypsin detection film shows different colors for the trypsin concentrations with different concentrations, and the trypsin concentration can be quantitatively detected through color change.

In particular, in the trypsin detection film, in one aspect, the polymeric film substrate can be a carrier or platform for the dye. Because the polymer film base material and the dye, especially bromocresol purple dye, 3',5,5' -tetramethyl benzidine dye, xylenol orange dye and the like have stronger ionic interaction, the dye can be well kept or attached on the polymer film base material, namely the dye can be stably combined with the polymer film base material. On the other hand, dyes, particularly bromocresol purple dye, 3',5,5' -tetramethylbenzidine dye, xylenol orange dye and the like are safe and nontoxic, can be combined with trypsin to change the color of the trypsin detection film, for example, the color can be changed from blue to yellow, and the degree of shade (hue) of the color change is different according to the concentration of the trypsin, so that the condition of the trypsin can be quantitatively detected through the color change. Of course, in other embodiments of the present application, the dye may also be discolored by other types of physical or chemical reactions between trypsin and the dye, which are not described herein again.

As can be seen from the above, in the embodiment of the present application, dyes such as bromocresol purple dye, 3',5,5' -tetramethylbenzidine dye, xylenol orange dye, etc. are directly used to combine or react with trypsin, so as to achieve the purpose of changing the color of the dyes, thereby achieving the detection effect. The concentration of trypsin can be determined by detecting the degree of change before and after the detection, for example, the concentration of trypsin in a liquid environment can be determined by the change of the shade (color tone), thereby assisting the examination and the corresponding treatment. The trypsin detection film is applied to the detection of trypsin, and has the characteristics of simple operation, obvious color change, quick detection, high efficiency, low requirement on detection personnel and the like.

In some embodiments, the polymeric film substrate comprises a polyionic liquid film (polyionic film) comprising an ionic liquid.

Preferably, the ionic liquid includes, but is not limited to, at least one of imidazole ionic liquid, pyridine ionic liquid, quaternary ammonium salt ionic liquid, quaternary phosphine ionic liquid or pyrrolidine ionic liquid. It is understood that the ionic liquid used to prepare the polymer film substrate may be a functionalized ionic liquid commonly used in the art, depending on the function that the ionic liquid performs. Illustratively, the ionic liquid may be imidazole ionic liquid, pyridine ionic liquid, quaternary ammonium salt ionic liquid, pyrrolidine ionic liquid, or the like. The specific type of ionic liquid in the examples of the present application is not limited, and several of the ionic liquids listed above may be used, and other types of ionic liquids known in the art may also be used.

Preferably, the ionic liquid monomers forming the polyionic liquid membrane include bromobutane and vinylimidazole. It is understood that bromobutane and vinylimidazole can react and form ionic liquid monomers.

Preferably, the base film monomer forming the polyionic liquid film includes, but is not limited to, acrylonitrile. The base film monomer can be acrylonitrile, or a mixture of acrylonitrile and styrene, or other base film monomers with similar functions or functions commonly used in the field.

Preferably, the crosslinking agent for forming the polyion liquid film includes, but is not limited to, N-methylenebisacrylamide (N, N' -methanediylbisprop-2-enamide, abbreviated as MBA). The MBA is used as a cross-linking agent, plays a role in bridging among molecular monomers, and molecules are mutually bonded and cross-linked to form a net structure to promote the inter-molecular chain bonding of the polymer. In addition, the crosslinking agent may be other crosslinking agents having similar properties or functions commonly used in the art.

Preferably, the initiator for forming the polyion liquid film includes, but is not limited to, 2,4,6- (trimethylbenzoyl) diphenylphosphine oxide (Diphenyl (2,4,6-trimethylbenzoyl) phosphinoxide, abbreviated as TPO). TPO belongs to a photoinitiator, is a light yellow solid, mainly plays a role in photocuring, is a high-efficiency universal ultraviolet photoinitiator, and can be used for initiating the UV polymerization reaction of an unsaturated prepolymerization system. In addition, the initiator may be other initiators commonly used in the art having similar properties or functional effects. For example, the initiator may be an initiator commonly used in the art, such as photoinitiator 907, photoinitiator 184, azobisisobutyronitrile, benzoin and derivatives thereof, and the like. One skilled in the art can select an appropriate initiator depending on the specific type of ionic liquid monomer, base film monomer, etc.

It should be noted that, in the embodiments of the present application, the specific type of the above-mentioned ionic liquid, the specific type of the base film monomer, the specific type of the cross-linking agent, the specific type of the initiator, and the like are not limited, and various types commonly used in the art may be adopted as long as the purpose and the application scenario of the present invention are not limited. For convenience of description, in the examples of the present application, MBA is mainly used as a cross-linking agent, TPO is mainly used as an initiator, acrylonitrile is used as a basement membrane monomer, and an ionic liquid monomer formed by bromobutane and vinyl imidazole is used as an example to specifically describe the trypsin detection membrane and the preparation method thereof. However, those skilled in the art will understand that the principles of the present disclosure may be implemented in any suitable polymer film substrate stock. Further, descriptions of well-known functions or actions may be omitted for clarity and conciseness.

Preferably, the concentration of the dye is 0.25-2.5 mg/mL, preferably 1-2 mg/mL; typically, but not by way of limitation, it may be, for example, 0.25mg/mL, 0.5mg/mL, 1mg/mL, 1.5mg/mL, 2mg/mL, 2.5mg/mL, or the like. The dye with a proper concentration range is adopted, so that the final display effect is better, and the accurate detection of the trypsin concentration is more facilitated.

Preferably, the solvent for the dye comprises water and/or an alcohol solvent. For example, the solvent may be a lower alcohol, and may further be an alcohol solvent such as ethanol. That is, bromocresol purple dye, 3',5,5' -tetramethylbenzidine dye, xylenol orange dye, or the like may be dissolved in water or in an alcohol solvent to form a dye solution.

Preferably, the polymer film substrate is immersed in the dye at a temperature of 20 to 40 ℃, preferably 25 to 35 ℃. The immersion temperature may be room temperature, and may be, for example, 20 ℃, 25 ℃, 30 ℃, 40 ℃ or the like.

Preferably, the polymer film substrate is immersed in the dye for 15 to 30min, preferably 18 to 22 min. Typical but non-limiting examples are 15min, 20min, 22min, 25min, 30min, etc. Therefore, under the appropriate time and temperature range, the polymer film substrate and the dye can be better combined, the property of the dye cannot be changed, and the obtained trypsin detection film has good performance and high efficiency.

In some embodiments, a method of making a polymeric film substrate comprises the steps of:

providing a substrate assembly, wherein the substrate assembly comprises a substrate and a first lubricant arranged on the substrate;

placing the film-forming solution of the polymer film substrate on the substrate assembly, and covering the cover plate with a second lubricant on the film-forming solution, wherein the film-forming solution is respectively contacted with the first lubricant and the second lubricant;

and after the polymerization reaction of the raw materials in the film forming solution, separating the polymer film substrate, the substrate assembly and the cover plate to obtain the polymer film substrate.

It will be appreciated that after the polymerization reaction has taken place and before the separation, a composite structure comprising the polymeric film substrate, the cover plate and the substrate assembly is obtained, and then, after the separation step, the polymeric film substrate is separated from the cover plate and substrate assembly to obtain the polymeric film substrate.

In some embodiments, the substrate assembly further comprises a tinfoil, the tinfoil disposed on the substrate, and the first lubricant disposed on the tinfoil. It is to be understood that the substrate assembly may include the substrate and the first lubricant, or may also include the substrate, the tinfoil, and the first lubricant. When the substrate assembly comprises tinfoil, the tinfoil needs to be flatly laid on the substrate or the tinfoil is flatly wrapped on the substrate, and then the first lubricant can be arranged on the tinfoil, which is more beneficial to the preparation of the polymer film substrate.

The preparation method of the polymer film substrate provided by the embodiment of the invention has the characteristics of high product rate, high reaction rate and energy consumption saving. Meanwhile, the whole process is simple and convenient to operate, low in requirement on experimental equipment and high in processing safety. In addition, the polymer film base material prepared by the preparation method has stable structure, easy stripping and low irritation.

According to the preparation method of the polymer film base material, the tin foil and the lubricant are used, so that the separation is formed between the film forming solution and the cover plate and/or the base plate, the film forming solution before film forming cannot be directly contacted with the base plate and/or the cover plate, the influence of the cover plate and/or the base plate on the film forming quality in the film forming process is reduced, the integrity and the thickness uniformity of the polymer film base material are ensured, and the time required by the separation of the polymer film base material can be greatly shortened.

Specifically, the substrate may be a glass plate, a stainless steel plate, a hard plastic plate that is not easily penetrated by ultraviolet light, or the like. Among these substrates, the substrate is preferably a glass plate. The glass plate has the advantages of easily available raw materials and low cost, and has good heat resistance, and is easy to cool after polymerization reaction under ultraviolet irradiation, thereby shortening the operation time.

Specifically, the cover plate may be a glass plate, a rigid plastic plate, or the like. Preferably, the cover plate can be a transparent glass plate or a transparent rigid plastic plate. The transparent glass plate or the transparent hard plastic plate can enable the polymerization reaction to be carried out under the irradiation of ultraviolet, so that the reaction speed is increased, and an alternative scheme is provided for the polymerization reaction.

In particular, the lubricant used, such as the first lubricant or the second lubricant, needs to be inert to and non-interfering with ultraviolet light. The first lubricant and the second lubricant may be of the same type or of different types.

In some embodiments, the first lubricant and the second lubricant are each independently selected from at least one of white petrolatum, silicone oil, paraffin, mineral oil, or grease; illustratively, the first lubricant may be white petrolatum, may be silicone oil, may be mineral oil, etc., and the second lubricant may be white petrolatum, may be silicone oil, may be grease, etc.

In the field of medical devices, the above lubricants employed need to be non-toxic, non-corrosive, non-residue and transparent in the coating. Especially for the fields with high safety requirements, such as sensors, drug controlled release and the like, the lubricant has higher requirements, and common medical grade lubricants or food grade lubricants can be adopted.

Specifically, in the method for producing the polymer film substrate, a deposition solution may be prepared in advance. And then spreading the tinfoil on the substrate flatly, or wrapping the substrate flatly by the tinfoil, or wiping the tinfoil by a dust-free cloth until the tinfoil has no wrinkles, wherein the smooth surface of the tinfoil faces upwards, then coating a first lubricant such as white vaseline on the tinfoil, and continuously wiping the tinfoil by the dust-free cloth until the surface is smooth. Then covering the prepared film-forming liquid on the tinfoil with the first lubricant, uniformly coating, and covering the cover plate which is coated with the second lubricant in advance on the tinfoil loaded with the film-forming liquid; it is understood that the upper and lower surfaces of the deposition solution may be contacted with the second lubricant and the first lubricant, respectively.

Optionally, the substrate is wetted with a wetting solution prior to laying the tinfoil on the substrate. The purpose of wetting the substrate is to exclude air between the substrate and the tinfoil. And, through the laminating nature of wetting solution and tin foil increase the cohesion of base plate and tin foil, smooth the tin foil more easily to improve the roughness on tin foil surface. The wetting solution for wetting the substrate may be various, but is preferably water, ethanol or a mixed solution thereof from the viewpoint of source, cost and environmental protection.

Additionally, in other embodiments, the substrate assembly may include only the substrate. Specifically, in the method for preparing the polymer film substrate, a deposition solution may be prepared in advance, and then a first lubricant such as white vaseline is applied on the substrate, and the first lubricant is wiped with a dust-free cloth until the surface is smooth. Then, the prepared deposition solution was coated on the substrate with the first lubricant, and uniformly coated, and then the cover plate previously coated with the second lubricant was coated on the substrate carrying the deposition solution. It is understood that the upper and lower surfaces of the deposition solution may be contacted with the second lubricant and the first lubricant, respectively.

Specifically, in some embodiments, a method of preparing a deposition solution comprises:

uniformly mixing the ionic liquid monomer and the base membrane monomer, adding a cross-linking agent and an initiator, and then carrying out second ultrasonic treatment to obtain a film forming solution;

preferably, the time of the second ultrasonic treatment is 10-30 min; typical but non-limiting examples are 10min, 15min, 20min, 25min, 30min, etc.

Preferably, the method for preparing the film-forming solution further comprises performing first ultrasonic treatment on the ionic liquid monomer, wherein the time of the first ultrasonic treatment is 10-30 min; typical but non-limiting examples are 10min, 15min, 20min, 25min, 30min, etc.

Compared with the existing 'two-step method' for preparing ionic liquid, the preparation method provided by the embodiment of the application can obviously improve the preparation efficiency of the deposition solution by using an ultrasonic method, greatly shortens the preparation time, and is easy to operate and good in controllability. Therefore, the preparation efficiency of the polymer film substrate and the trypsin detection film can be further improved by adopting the preparation method of the film-forming solution.

According to the embodiment of the invention, different deposition solutions can be selected according to different requirements. The ionic liquid in the film-forming solution may be one or more of imidazole ionic liquid, pyridine ionic liquid, quaternary ammonium salt ionic liquid, quaternary phosphine ionic liquid or pyrrolidine ionic liquid, or may be other types of ionic liquids known in the art.

Preferably, the ionic liquid monomers include bromobutane and vinylimidazole.

Preferably, the base film monomer comprises acrylonitrile.

Preferably, the crosslinking agent comprises N, N-Methylenebisacrylamide (MBA).

Preferably, the initiator comprises 2,4,6- (trimethylbenzoyl) diphenylphosphine oxide (TPO).

Specifically, in the preparation of the deposition solution, the molar ratio of bromobutane to vinylimidazole may be from 2:1 to 1:1, for example, 1: 1. To ensure complete reaction, the mass of acrylonitrile needs to be greater than or equal to the sum of the masses of bromobutane and vinylimidazole. Considering the reaction ratio, conversion rate, dosage and subsequent cleaning treatment process of the three, the mass of the acrylonitrile is preferably the sum of the mass of the bromobutane and the mass of the vinylimidazole. The mass of the crosslinking agent is 8 to 12 wt%, for example, 8, 9, 10, 12 wt%, etc., based on the total mass of bromobutane, vinylimidazole and acrylonitrile. The mass of the initiator is 1 to 4 weight percent calculated by the total mass of bromobutane, vinyl imidazole and acrylonitrile; for example, it may be 1 wt%, 1.5 wt%, 2 wt%, 3 wt%, 4 wt%, etc. It should be understood that the ratio of the above raw materials is not limited thereto, and may be adjusted appropriately according to the actual process conditions.

Specifically, the preparation of the deposition solution may comprise the following steps.

Mixing bromobutane and vinyl imidazole in equal molar ratio, and carrying out ultrasonic treatment on the obtained mixed solution for 15min until the bromobutane and the vinyl imidazole are fully mixed;

removing impurities, and adding acrylonitrile with the mass sum of bromobutane and vinyl imidazole equal to that of the bromobutane and the vinyl imidazole;

then adding MBA with the mass ratio of 8 wt% calculated by the total mass of the bromobutane, the vinyl imidazole and the acrylonitrile and TPO with the mass ratio of 1 wt% calculated by the total mass of the bromobutane, the vinyl imidazole and the acrylonitrile, and carrying out ultrasonic treatment for 15min after the addition to obtain a film-forming solution, wherein the obtained film-forming solution is clear and transparent liquid.

In the preparation step, ultrasonic treatment can add an energy field to the mixed liquid of the bromobutane and the vinyl imidazole, thereby accelerating the reaction.

Further, in the method for preparing the trypsin detection film, each raw material in the deposition solution is subjected to a polymerization reaction, and in some embodiments, the polymerization reaction is performed under irradiation of ultraviolet light.

Wherein the wavelength of the ultraviolet light is preferably 250-400 nm; typically, but not limited to, for example, 250nm, 300nm, 325nm, 400nm, etc.

The time of ultraviolet irradiation is preferably 10-30 min; typically but not limitatively, for example, 10min, 20min, 30min, etc. may be mentioned.

Alternatively, the polymerization reaction may be carried out under heating while being carried out under irradiation of ultraviolet light. The heating temperature may be 20 to 60 ℃, and typically, but not limited to, 20 ℃, 30 ℃, 40 ℃, 50 ℃, 60 ℃ or the like.

The polymerization reaction is carried out under the condition, which is beneficial to obtaining a polymer film base material with excellent performance and has higher efficiency.

The polymerization reaction may be initiated by an initiator. The initiator may be any initiator commonly used in the art, such as photoinitiator 907, photoinitiator 184, azobisisobutyronitrile, benzoin and derivatives thereof, etc., and those skilled in the art may select an appropriate initiator according to the specific components of the film-forming solution.

Further, in the method for producing a trypsin detection film, the raw materials in the deposition solution are polymerized and then separated (for example, the polymer film base is separated from the cover plate and/or the substrate assembly). In some embodiments, the separating comprises: removing the substrate assembly, placing the cover plate attached with the polymer film substrate in a standing solution, and standing for 10-30 min to automatically separate the polymer film substrate from the cover plate in the standing solution, thereby obtaining the polymer film substrate;

or removing the cover plate, placing the substrate assembly attached with the polymer film substrate in a standing solution, standing for 10-30 min to separate the polymer film substrate from the substrate assembly in the standing solution, and removing the substrate assembly to obtain the polymer film substrate.

Furthermore, when the polymer film base material and the substrate assembly are separated, the tin foil and the first lubricant are arranged between the polymer film base material and the substrate to serve as barriers, so that the substrate and the tin foil attached with the polymer film base material can be easily separated. Compared with the separation substrate and the polymer film base material, the thickness of the tin foil is very thin, and the first lubricant is arranged between the tin foil and the polymer film base material, so that the tin foil and the polymer film base material are easier to separate. Specifically, in the process of separating the polymer film substrate from the tinfoil, the tinfoil and the polymer film substrate can be placed in a solution, and the two are naturally separated through the solution, or can be separated through a mechanical separation mode (such as manual stripping of the tinfoil) so as to obtain a complete polymer film substrate.

Alternatively, the standing solution may be water or other solvent.

By the method, the polymer film substrate can be automatically separated from the cover plate or the base plate or the tinfoil, the operation is simple, the yield is improved, and the production efficiency is improved.

Optionally, the polymer film substrate obtained by separation is cleaned, for example, ultrasonic cleaning can be sequentially performed in clean water, absolute ethyl alcohol and clean water.

As can be seen from the above, according to the preparation method of the embodiment of the present invention, through the use of the tinfoil, the first lubricant and the second lubricant, not only the integrity of the polymer film substrate and the uniform stability of the film thickness can be ensured, but also the polymer film substrate can be more easily separated, that is, the polymer film substrate is automatically peeled off, and the time required for separation is greatly shortened. Meanwhile, the preparation of the film-forming solution by adopting an ultrasonic method also greatly shortens the time for preparing the film-forming solution, and has simple and efficient operation. Therefore, compared with the existing film preparation method, the preparation method of the polymer film substrate has the characteristics of simplicity, high efficiency, short time and the like.

Therefore, the preparation method of the trypsin detection film provided by the embodiment of the application has the advantages of simple and convenient synthesis, easy operation, low technical threshold, easy separation of polymer film base materials, short preparation time, high preparation efficiency, easy realization of large-scale production and the like, is a simple, convenient and efficient preparation method, and is easy for large-scale production and application.

In a second aspect, in some embodiments, there is provided a trypsin detection film prepared by the above method for preparing a trypsin detection film.

The trypsin detection film comprises:

a polymeric film substrate; and

a dye attached to a polymeric film substrate.

In some embodiments, the dye is adapted to interact with trypsin, and the color of the dye is different in environments with different concentrations of trypsin.

In some embodiments, the dye includes, but is not limited to, at least one of bromocresol purple dye, 3',5,5' -tetramethylbenzidine dye, triarylmethane-based dye, xylenol orange dye, or metal complex-based dye.

In some embodiments, the polymeric film substrate comprises a polyionic liquid film comprising an ionic liquid.

Preferably, the ionic liquid includes but is not limited to at least one of imidazole ionic liquid, pyridine ionic liquid, quaternary ammonium salt ionic liquid, quaternary phosphine ionic liquid or pyrrolidine ionic liquid;

preferably, the ionic liquid monomers forming the polyionic liquid film include, but are not limited to, bromobutane and vinylimidazole;

preferably, the base film monomers forming the polyionic liquid film include, but are not limited to, acrylonitrile;

preferably, the polyionic liquid film-forming crosslinking agent includes, but is not limited to, N-methylenebisacrylamide;

preferably, the initiator for forming the polyionic liquid film includes, but is not limited to, 2,4,6- (trimethylbenzoyl) diphenylphosphine oxide.

It should be understood that the same or similar parts of the trypsin detection film of the second aspect as those of the method for preparing the trypsin detection film of the first aspect can be referred to the above description of the method for preparing the protease detection film of the first aspect, and will not be described herein again.

In a third aspect, in some embodiments, there is provided a detection film prepared by the above method for preparing a trypsin detection film or a use of the trypsin detection film in detecting trypsin. The detection method comprises the following steps:

and (3) placing the trypsin detection film in the liquid to be detected, and enabling the dye in the trypsin detection film to contact or interact with the liquid to be detected.

In some embodiments, the detection method further comprises: the color change of the trypsin detection film was observed.

In some embodiments, the detection method further comprises: in the environment containing the solutions to be detected with different trypsin concentrations, the colors of the trypsin detection films are different, and the trypsin concentration is judged according to the different colors displayed by the trypsin detection films.

It should be noted that the color of the trypsin detection film is also displayed depending on the immersion time or immersion temperature. Specifically, for example, in the case where the time for immersing the polymer film substrate in the dye is the same, and in the case where the temperature for immersing the polymer film substrate in the dye is the same, the color change of the trypsin detection film before and after the detection is affected by the concentration of trypsin. In the case where the polymer film substrate is immersed in the dye for a different time or the polymer film substrate is immersed in the dye for a different temperature, the color change of the trypsin detection film before and after the detection may be influenced by the combination of the concentration of trypsin and the immersion time or immersion temperature. Therefore, it is necessary to keep the time and temperature for immersing the polymer film substrate in the dye within appropriate ranges, or to keep the time and temperature for immersing the polymer film substrate in the dye the same when detecting a series of trypsin concentrations, in order to minimize the influence of the immersion time and immersion temperature on the color change of the trypsin detection film.

The trypsin detection film provided by the embodiment of the invention is applied to trypsin detection, has the advantages of simple and convenient operation, obvious change before and after detection, quick detection, high efficiency and the like, and can relieve the defects of complex equipment, high technical requirement, complex detection, high cost and the like of the existing trypsin detection method.

It should be understood that, in the application of the trypsin detection film of the third aspect, the same or similar parts as those in the trypsin detection film and the preparation method of the first and second aspects can be referred to the above description of the trypsin detection film and the preparation method, and will not be described again here.

In a fourth aspect, there is provided in some embodiments a trypsin detection kit comprising the aforementioned trypsin detection membrane.

As can be seen from the above, the trypsin detection kit according to the embodiment of the present invention includes the trypsin detection film, and thus has at least the same advantages as the trypsin detection film, and the preparation method and application thereof, and further description thereof is omitted. The trypsin detection kit has the function principle that the dye in the trypsin detection film is combined or reacted with trypsin for color development, and when the concentration of the trypsin is different, the trypsin detection film has different colors, so that the concentration of the trypsin can be judged according to the change degree of the colors of the trypsin detection film before and after detection.

In some embodiments, the trypsin detection kit further comprises a trypsin detection standard colorimetric card, or a trypsin detection standard color scale.

Further, the trypsin detection kit may further comprise a packaging box and instructions for use.

The trypsin detection kit can be provided with a packaging box, and a trypsin detection film and a standard colorimetric card can be placed in the packaging box, and an instruction for use and the like can also be placed in the packaging box. The number of the trypsin detecting films is not limited, and for example, 1 to 5 trypsin detecting films or more trypsin detecting films may be placed.

According to an embodiment of the present invention, the trypsin detection using the kit comprises:

after the trypsin detection film is prepared, recording the color of the trypsin detection film before detection in a picture shooting mode, or carrying out contrast recording on the trypsin detection film and a standard color on a kit;

then immersing the trypsin detection film in the trypsin solution, wherein the color of the trypsin detection film can be slowly observed to change after several seconds, for example, the color can be changed from blue to green, after the color is stable, the trypsin detection film is taken out, the color of the trypsin detection film after detection is recorded, and the color of the trypsin detection film after detection is compared with the color of the trypsin detection film before detection, or the color can be contrasted with a color card number, or the color can be contrasted with a standard color gradation or a standard colorimetric card in a kit, wherein the color depth change corresponds to different trypsin concentrations.

The standard color scale or standard colorimetric card for trypsin detection can be prepared by the following method:

preparing a series of trypsin solutions with a concentration, for example, a series of trypsin solutions with a concentration of 0ug/mL, 0.5ug/mL, 5ug/mL, 10ug/mL, 25ug/mL, 100 ug/mL;

respectively placing the trypsin solutions with the concentrations in colorimetric containers, respectively adding the same trypsin detection films, standing for a certain time, taking out the trypsin detection films after the color is stable, recording the color development result of the detected trypsin detection films by using image acquisition equipment such as a camera and the like, and after collecting pictures, forming a trypsin standard color gradation by using the pictures with color gradients or printing the pictures (processed by a computer) to prepare the trypsin detection standard colorimetric card.

In addition, if the film is not sensitive to color, the color of the trypsin detection film can be analyzed by using color analysis software, for example, HSI RGB value in MATLAB software (the value can fluctuate to a certain extent due to factors such as environment) can be used, and the color of the trypsin detection film can be quantified by using color space knowledge. The comparative relationship between the RGB color values of the trypsin detection film is shown in FIG. 1.

As can be seen from the data in FIG. 1, the RGB values change more obviously, and the color change of the trypsin detection film after the trypsin with different concentrations is dyed can be clearly reflected, so that the concentration of the trypsin can be judged.

It is understood that the RGB model is a commonly used color information expression method, which uses the brightness of three primary colors, red, green and blue, to quantitatively express the color. The model is also called additive color mixing model, i.e. a method for realizing color mixing by superposing RGB three-color lights on each other, and any color can be represented by a point in a three-dimensional space in an RGB color space. Therefore, the color variation can be quantified and judged by RGB values. After the pictures of the trypsin detection film are collected, the RGB color analyzer can be used or the pictures can be imported into color analysis software, such as MATLAB, to quantify the color values for comparison, at which time a standard color chart may not be needed. Or, a standard color comparison card can be prepared in advance for comparison, and only the standard color comparison card needs to be compared without importing analysis.

In order to facilitate an understanding of the invention, the invention will now be further described with reference to the following specific examples. In the following specific examples, the raw materials used are all commercially available unless otherwise specified.