Tumor abnormal sugar chain detection test paper and preparation method thereof

Abstract

The invention relates to the technical field of abnormal tumor carbohydrate chain detection, in particular to abnormal tumor carbohydrate chain detection test paper and a preparation method thereof.The preparation method comprises the following steps that a nitrocellulose membrane is cut to serve as a test paper substrate, the test paper substrate is evenly coated with a detection complex solution, the test paper substrate is placed in an oven at 37 DEG C to be dried for 2-3 h, and the abnormal tumor carbohydrate chain detection test paper is obtained. And dropwise adding a standard substance solution with known concentration at one end of the test paper to serve as a quality control line, dividing a reaction area on the test paper, filling the reaction area into an aluminum foil bag for sealing, and storing in a dark place at 4 DEG C to obtain the tumor abnormal sugar chain detection test paper. According to the test paper prepared by the invention, only a sample needs to be dropwise added to a specified reaction area, complicated operation steps or professional equipment is not needed, the use threshold is reduced, and the rapid preliminary screening is facilitated. A user can observe the color change or agglutination reaction on the test paper through naked eyes, so that whether the abnormal sugar chain is contained in a sample or not is quickly judged, and the detection efficiency is improved.

Description

Technical Field

[0001] The present invention relates to the technical field of abnormal tumor sugar chain detection, and in particular to a test strip for abnormal tumor sugar chain detection and a preparation method thereof. Background Art

[0002] The tumor abnormal glycan test strip is a diagnostic tool for early detection of cancer risk. A prominent feature of tumor cell development and progression is abnormal changes in the carbohydrate structure on the cell membrane surface, a process known as abnormal glycosylation. Glycosylation is a key post-translational modification of proteins, affecting their function, stability, and localization. When normal cells undergo malignant transformation, the activity of glycosylation-modifying enzymes (such as glycosyltransferases and glycosidases) changes significantly, leading to abnormal changes in cell surface carbohydrate structure and the production of various abnormal glycan glycoproteins (TAPs). TAPs are a class of abnormal glycoproteins released into body fluids during tumor cell metabolism. They possess unique glycan structures that differ significantly from those produced by normal cells. Numerous studies have demonstrated a close relationship between TAPs and the development, progression, metastasis, and prognosis of malignant tumors. Detecting the presence and concentration of TAPs in body fluids (such as blood) can provide important insights for early detection, auxiliary diagnosis, therapeutic efficacy assessment, and monitoring of recurrence and metastasis. The core principle of TAP detection technology is that when normal cells become malignant, the activity of glycosylation modification enzymes changes, causing the carbohydrate structure on the cell membrane surface to change, thereby producing a variety of abnormal sugar chain glycoproteins, which are eventually released into body fluids.

[0003] In the prior art, since TAP is not a specific marker for tumor cells, it may also be produced in certain non-tumor conditions, such as autoimmune diseases, inflammation, and infection. Therefore, TAP test strips have a certain false positive rate, which means that non-tumor patients may be misdiagnosed as tumor patients. At the same time, some physiological or pathological conditions, such as pregnancy, diabetes, and active tuberculosis, may also affect the TAP test results, resulting in false positives or false negatives. In addition, the sensitivity of TAP test strips is affected by various factors, such as sample collection, storage conditions, and testing time. These factors can cause the sensitivity of the test strips to fluctuate, resulting in unstable test results and affecting the accuracy of the diagnosis. Although TAP test strips have certain advantages in early tumor screening, their sensitivity may still be insufficient for some early, tiny tumor lesions, making them difficult to accurately detect. Summary of the Invention

[0004] In order to solve the problems mentioned in the above background technology, the present invention provides a test strip for detecting abnormal sugar chains in tumors and a preparation method thereof.

[0005] In order to achieve the above object, the present invention adopts the following technical solutions: A method for preparing a test strip for detecting abnormal sugar chains in tumors comprises the following steps: A nitrocellulose membrane was cut and used as a test paper substrate. The detection complex solution was evenly coated on the test paper substrate and dried in a 37°C oven for 2-3 hours. TAP standard solutions with known concentrations of 100 ng / mL, 200 ng / mL, 500 ng / mL, and 1000 ng / mL were dripped onto one end of the test paper as a quality control line. The reaction zone, i.e., the area where agglutination reaction occurs after the sample is dripped, was marked on the test paper. The test paper was sealed in an aluminum foil bag and stored at 4°C in the dark to obtain a tumor abnormal sugar chain detection test paper. The detection complex solution includes a recognition element solution and a signal conversion element solution.

[0006] Furthermore, the detection complex solution is prepared by the following steps: S1. Add the aptamer or sugar-binding protein to a phosphate buffer at pH 7.4, add N-hydroxysuccinimide and 1-(3-dimethylaminopropyl)-3-ethylcarbodiimide, stir at room temperature for 2-3 hours, dialyze or centrifuge to obtain a recognition element solution; S2. In an oxygen-free and light-proof environment, silver nitrate is rapidly added to a solution containing 30-40% ascorbic acid, sodium citrate is added, and the mixture is heated and stirred until the solution turns yellow or light gray, and then cooled to room temperature to obtain a silver nanoparticle solution; S3, adding dimethyl terephthalate, ethylene glycol and tetrabutyl titanate to a reactor filled with methanol solvent, heating and stirring under nitrogen protection for 3-4 hours to obtain oligomers, continuing to add polyethylene glycol 200, heating and stirring for 4-6 hours, after the reaction is completed, removing unreacted ethylene glycol by vacuum distillation until no liquid is distilled out, adding N,N-dimethyl-2-propyl-2-enyloxyethanolamine and azobisisobutyronitrile while hot, controlling the reaction temperature, stirring and reacting for 24-48 hours, during which time toluene can be added from time to time to maintain the solution volume and concentration stable, to obtain a copolymer solution, uniformly dispersing the silver nanoparticle solution in the copolymer solution, stirring for 1-2 hours, to obtain a signal conversion element solution; S4. Mix the recognition element solution and the signal conversion element solution, and incubate at room temperature for 1-2 hours to obtain a detection complex solution; Among them, the aptamer is a single-stranded DNA or RNA molecule screened from a random library by SELEX technology, which can bind to the target TAP with high specificity. Glycoprotein is a lectin with the ability to recognize sugar chains, including concanavalin A (ConA), wheat germ agglutinin (WGA), ricin B chain, Datura agglutinin (DSL) or peanut agglutinin (PNA).

[0007] Furthermore, the area of ​​the test paper base is 5 cm×1 cm, the standard solution is dropped on a 1 cm×0.5 cm area of ​​the test paper, and the area of ​​the reaction zone is 2 cm×1 cm.

[0008] Furthermore, in step S1, the mass ratio of the aptamer or sugar-binding protein, phosphate buffer, N-hydroxysuccinimide and 1-(3-dimethylaminopropyl)-3-ethylcarbodiimide is (1-2):10:(0.55-0.57):(0.48-0.52).

[0009] Furthermore, in step S2, the mass ratio of silver nitrate, sodium citrate, and ascorbic acid is (1.5-1.8): (2-3): (8-10).

[0010] Furthermore, in step S2, the heating temperature is 90-100° C., the stirring speed is 50-100 rpm, and the reaction time is 20-30 min.

[0011] Furthermore, in step S3, the mass ratio of dimethyl terephthalate, ethylene glycol, tetrabutyl titanate, polyethylene glycol 200, N,N-dimethyl-2-propyl-2-enoxyethanolamine and azobisisobutyronitrile is (2.5-3.3): (1-1.5): (0.1-0.3): (0.8-1): (0.7-0.8): (0.05-0.1), and the mass ratio of the copolymer solution to the silver nanoparticle solution is (1.8-2.2): (0.8-1).

[0012] Furthermore, in step S3, the heating temperature is 190-200° C., the rising temperature is 220-230° C., the reaction temperature is controlled to be 80-100° C., and the stirring speed is 50-100 rpm.

[0013] Furthermore, in step S4, the mass ratio of the identification element solution to the signal conversion element solution is (1-1.2): (0.7-0.8).

[0014] According to another aspect of the present invention, a test strip for detecting abnormal sugar chains in tumors prepared by the above-mentioned preparation method is provided.

[0015] Beneficial effects of the present invention: 1. In the technical solution of the present invention, the aptamer or sugar-binding protein maintains its active conformation in a phosphate buffer at a pH of 7.4. After activation with N-hydroxysuccinimide and 1-(3-dimethylaminopropyl)-3-ethylcarbodiimide, the carboxyl groups on the protein surface are converted into active esters, which can be covalently linked to amino groups on other molecules or carriers, ensuring accurate identification of target molecules during the detection process and improving the accuracy and effectiveness of the test strips.

[0016] 2. In the technical solution of the present invention, a polyethylene terephthalate-polyethylene glycol block copolymer is obtained by copolymerizing dimethyl terephthalate with ethylene glycol and polyethylene glycol. The block copolymer has hydrophilic polyethylene glycol segments and hydrophobic polyethylene terephthalate segments, which enable the copolymer to form stable micelles or vesicle structures in aqueous solution. When silver nanoparticles are encapsulated therein, the polyethylene glycol segments can prevent direct contact between the nanoparticles, thereby effectively preventing agglomeration and precipitation, and serve as a bridge between the recognition element and the silver nanoparticles. The polyethylene terephthalate segments provide good chemical stability and can resist the influence of the external environment on the performance of the silver nanoparticles. At the same time, the introduction of N,N-dimethyl-2-propyl-2-enoxyethanolamine further enhances the chemical stability of the copolymer, enabling it to maintain structural integrity under various conditions.

[0017] 3. In the technical solution of the present invention, during the binding process between the recognition element and the signal conversion element, the active ester on the protein surface covalently links with the amino groups on the silver nanoparticle / copolymer complex, forming a stable complex. The polyethylene glycol segments and N,N-dimethyl-2-propyl-2-enyloxyethanolamine exhibit certain biocompatibility, reducing interactions with organisms and promoting interactions between the detection complex and biological cells. This improves recognition efficiency and accuracy, reduces immunogenicity, and helps mitigate the cytotoxic effects of the detection complex.

[0018] 4. In the present invention, the silver nanoparticles in the signal conversion element solution exhibit an amplified optical effect, enabling sensitive detection even at very low target molecule concentrations through changes in the silver nanoparticles' optical properties. By modulating the surface plasmon resonance effect of the silver nanoparticles to enhance changes in their optical properties, the detection complex produces a more sensitive and pronounced signal change when identifying abnormal tumor sugar chains.

[0019] 5. The present invention requires only the sample to be dropped into the designated reaction area, eliminating the need for complex procedures or specialized equipment. This lowers the barrier to entry and facilitates rapid initial screening. Users can visually observe color changes or agglutination reactions on the test strip to quickly determine whether the sample contains abnormal sugar chains, improving detection efficiency. DETAILED DESCRIPTION

[0020] The following will clearly and completely describe the technical solutions of the present invention in conjunction with the embodiments of the present invention. Obviously, the embodiments described are only some embodiments of the present invention, not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making any creative efforts shall fall within the scope of protection of the present invention.

[0021] Unless otherwise specified, the raw materials used in the present invention are all conventional products purchased from the market.

[0022] Preparation Example 1 The detection complex solution is prepared by the following steps: S1. Add 100 mg of concanavalin A to 1 g of phosphate buffer at pH 7.4, add 55 mg of N-hydroxysuccinimide and 48 mg of 1-(3-dimethylaminopropyl)-3-ethylcarbodiimide, stir at room temperature for 2 h, and centrifuge to obtain a recognition element solution. S2. In an oxygen-free and light-proof environment, prepare a 30% ascorbic acid solution with 800 mg of ascorbic acid and deionized water, quickly add 150 mg of silver nitrate, and then add 200 mg of sodium citrate. Heat to 90° C. and stir at 50 rpm for 20 min until the solution turns light gray. Cool to room temperature to obtain a silver nanoparticle solution. S3. Add 250 mg of dimethyl terephthalate, 100 mg of ethylene glycol, and 10 mg of tetrabutyl titanate to a reactor containing 1 g of methanol solvent. Under nitrogen protection, heat to 190° C., stir at 50 rpm for 3 h to obtain an oligomer. Continue to add 80 mg of polyethylene glycol 200, raise the temperature to 220° C., and stir at 50 rpm for 4 h. After the reaction is completed, remove the unreacted ethylene glycol by vacuum distillation until no liquid is distilled out. Add 70 mg of N,N-dimethyl-2-propyl-2-enyloxyethanolamine and 5 mg of azobisisobutyronitrile while hot, control the reaction temperature to 80° C., stir and react for 24 h to obtain a copolymer solution. Evenly disperse 80 mg of the silver nanoparticle solution in 180 mg of the copolymer solution and stir for 1 h to obtain a signal conversion element solution. S4. Mix 100 mg of the recognition element solution with 70 mg of the signal conversion element solution, and incubate at room temperature for 1 h to obtain a detection complex solution.

[0023] Preparation Example 2 The detection complex solution is prepared by the following steps: S1. Add 150 mg of wheat germ agglutinin to 1 g of phosphate buffer at pH 7.4, add 56 mg of N-hydroxysuccinimide and 50 mg of 1-(3-dimethylaminopropyl)-3-ethylcarbodiimide, stir at room temperature for 2.5 h, dialyze or centrifuge to obtain a recognition element solution; S2. In an oxygen-free and light-proof environment, prepare a 35% ascorbic acid solution with 900 mg of ascorbic acid and deionized water, quickly add 165 mg of silver nitrate, and then add 250 mg of sodium citrate. Heat to 95° C. and stir at 60 rpm for 25 min until the solution turns light gray. Cool to room temperature to obtain a silver nanoparticle solution. S3. Add 300 mg of dimethyl terephthalate, 125 mg of ethylene glycol, and 20 mg of tetrabutyl titanate to a reactor containing 1 g of methanol solvent. Under nitrogen protection, heat to 195° C., stir at 60 rpm for 3.5 hours to obtain an oligomer. Continue to add 90 mg of polyethylene glycol 200, raise the temperature to 225° C., and stir at 60 rpm for 5 hours. After the reaction is completed, remove unreacted ethylene glycol by vacuum distillation until no liquid is distilled out. Add 75 mg of N,N-dimethyl-2-propyl-2-enyloxyethanolamine and 8 mg of azobisisobutyronitrile while hot, control the reaction temperature to 90° C., stir and react for 36 hours to obtain a copolymer solution. Evenly disperse 90 mg of the silver nanoparticle solution in the 200 mg copolymer solution and stir for 1.5 hours to obtain a signal conversion element solution. S4. Mix 110 mg of the recognition element solution with 75 mg of the signal conversion element solution, and incubate at room temperature for 1.5 h to obtain a detection complex solution.

[0024] Preparation Example 3 The detection complex solution is prepared by the following steps: S1. Add 200 mg of Datura stramonium agglutinin to 1 g of phosphate buffer at pH 7.4, add 57 mg of N-hydroxysuccinimide and 52 mg of 1-(3-dimethylaminopropyl)-3-ethylcarbodiimide, stir at room temperature for 3 h, dialyze or centrifuge to obtain a recognition element solution; S2. In an oxygen-free and light-proof environment, prepare a 40% ascorbic acid solution with 1000 mg of ascorbic acid and deionized water, quickly add 180 mg of silver nitrate, and then add 300 mg of sodium citrate. Heat to 100° C. and stir at 100 rpm for 30 min until the solution turns light gray. Cool to room temperature to obtain a silver nanoparticle solution. S3. Add 330 mg of dimethyl terephthalate, 150 mg of ethylene glycol, and 30 mg of tetrabutyl titanate to a reactor containing 1 g of methanol solvent. Under nitrogen protection, heat to 200° C., stir at 100 rpm for 4 h to obtain an oligomer. Continue to add 100 mg of polyethylene glycol 200, raise the temperature to 230° C., and stir at 100 rpm for 6 h. After the reaction is completed, remove the unreacted ethylene glycol by vacuum distillation until no liquid is distilled out. Add 80 mg of N,N-dimethyl-2-propyl-2-enyloxyethanolamine and 10 mg of azobisisobutyronitrile while hot, control the reaction temperature to 100° C., stir and react for 48 h to obtain a copolymer solution. Evenly disperse 100 mg of the silver nanoparticle solution in 220 mg of the copolymer solution and stir for 2 h to obtain a signal conversion element solution. S4. Mix 120 mg of the recognition element solution with 80 mg of the signal conversion element solution, and incubate at room temperature for 2 h to obtain a detection complex solution.

[0025] Example 1 A method for preparing a test strip for detecting abnormal sugar chains in tumors comprises the following steps: A nitrocellulose membrane was cut into an area of ​​5 cm × 1 cm and used as a test paper substrate. The detection complex solution prepared in Preparation Example 1 was evenly coated on the test paper substrate and placed in a 37°C oven to dry for 2 h. TAP standard solutions with known concentrations of 100 ng / mL, 200 ng / mL, 500 ng / mL, and 1000 ng / mL were added dropwise to one end of the test paper (1 cm × 0.5 cm area) as a quality control line. A 1 cm × 0.5 cm reaction area was marked on the test paper, i.e., the area where agglutination reaction occurred after the sample was added. The test paper was placed in an aluminum foil bag, sealed, and stored in the dark at 4°C to obtain a tumor abnormal sugar chain detection test paper.

[0026] Example 2 A method for preparing a test strip for detecting abnormal sugar chains in tumors comprises the following steps: A nitrocellulose membrane was cut into an area of ​​5 cm × 1 cm and used as a test paper substrate. The detection complex solution prepared in Preparation Example 2 was evenly coated on the test paper substrate and placed in a 37°C oven to dry for 2.5 h. TAP standard solutions with known concentrations of 100 ng / mL, 200 ng / mL, 500 ng / mL, and 1000 ng / mL were added dropwise to one end of the test paper (1 cm × 0.5 cm area) as a quality control line. A 1 cm × 0.5 cm reaction area was marked on the test paper, i.e., the area where agglutination reaction occurred after the sample was added. The test paper was placed in an aluminum foil bag, sealed, and stored in the dark at 4°C to obtain a tumor abnormal sugar chain detection test paper.

[0027] Example 3 A method for preparing a test strip for detecting abnormal sugar chains in tumors comprises the following steps: A nitrocellulose membrane was cut into an area of ​​5 cm × 1 cm and used as a test paper substrate. The detection complex solution prepared in Preparation Example 3 was evenly coated on the test paper substrate and placed in a 37°C oven to dry for 3 h. TAP standard solutions with known concentrations of 100 ng / mL, 200 ng / mL, 500 ng / mL, and 1000 ng / mL were added dropwise to one end of the test paper (1 cm × 0.5 cm area) as a quality control line. A 1 cm × 0.5 cm reaction area was marked on the test paper, i.e., the area where agglutination reaction occurred after the sample was added. The test paper was placed in an aluminum foil bag, sealed, and stored in the dark at 4°C to obtain a tumor abnormal sugar chain detection test paper.

[0028] Comparative Example 1 The difference between this comparative example and Preparation Example 1 is that N-hydroxysuccinimide and 1-(3-dimethylaminopropyl)-3-ethylcarbodiimide are not added, and the remaining steps are the same as those in Preparation Example 1.

[0029] Comparative Example 2 The difference between this comparative example and Preparation Example 2 is that dimethyl terephthalate is not added, and the remaining steps are the same as those in Preparation Example 2.

[0030] Comparative Example 3 The difference between this comparative example and Preparation Example 3 is that N,N-dimethyl-2-propyl-2-enyloxyethanolamine is not added, and the remaining steps are the same as those in Preparation Example 3.

[0031] Comparative Example 4 The difference between this comparative example and Example 1 is that the detection complex solution prepared in Comparative Example 1 is used, and the remaining steps are the same as those in Example 1.

[0032] Comparative Example 5 The difference between this comparative example and Example 2 is that the detection complex solution prepared in Comparative Example 2 is used, and the remaining steps are the same as those in Example 2.

[0033] Comparative Example 6 The difference between this comparative example and Example 3 is that the detection complex solution prepared in Comparative Example 3 is used, and the remaining steps are the same as those in Example 3.

[0034] (I) Sensitivity test: Weigh the TAP standard and prepare a series of TAP solutions of different concentrations using phosphate buffer with a pH value of 7.4. The specific concentrations are: 10 ng / mL, 20 ng / mL, 50 ng / mL, 100 ng / mL, 200 ng / mL, 500 ng / mL, and 1000 ng / mL. Use a micropipette to draw 50 μL of TAP solution and add it dropwise to the reaction area on the test paper prepared in Examples 1-3 and Comparative Examples 4-6, respectively. After 5 minutes, observe the color development results of the test paper. If the reaction area of ​​the test paper shows obvious gray, light brown or dark brown color changes, it is recorded as positive, and the number of positive results at each concentration is recorded. Repeat the experiment 3 times and calculate the positive rate. The results are shown in Table 1:

[0035]

[0036] (II) Specificity test: Five healthy human serum samples (containing no TAP or containing very low levels) were collected. 50 μL of each healthy human serum sample was pipetted using a micropipette and added dropwise to the reaction zone of the test strips prepared in Examples 1-3 and Comparative Examples 4-6. After 5 minutes, the color development results of the test strips were observed. The color development results for each sample were recorded, and the false positive rate was calculated: false positive rate = number of color development samples / total number of experimental results × 100%. The experiment was repeated 50 times for each example and comparative example. The results are shown in Table 2:

[0037]

[0038] As shown in Table 1, Examples 1-3 all showed a 100% positive rate across the TAP concentration range of 10 ng / mL to 1000 ng / mL, demonstrating that the test strips have extremely high sensitivity and can accurately identify and reflect TAP concentrations from low to high. Comparative Example 4 had a lower positive rate when the TAP concentration was below 100 ng / mL, and Comparative Example 5 also had a lower positive rate when the TAP concentration was below 200 ng / mL.

[0039] As shown in Table 2, Examples 1-3 all achieved a 0% false-positive rate across 50 replicates, demonstrating the high specificity of the test strips, which accurately distinguish healthy human serum samples (those without TAP or with very low TAP levels) from those containing TAP. The higher false-positive rates of Comparative Examples 4-6 compared to the Examples may be due to the enhanced reactivity of the test strips to nonspecific substances.

[0040] In Examples 1-3, concanavalin A, wheat germ agglutinin, and Datura stramonium agglutinin serve as recognition elements, initiating detection by specifically binding to TAP. N-hydroxysuccinimide and 1-(3-dimethylaminopropyl)-3-ethylcarbodiimide may help stabilize the structure of the recognition element, enhancing its binding to TAP and thereby increasing sensitivity. A signal conversion element composed of silver nanoparticles and a copolymer converts the binding signal of the recognition element to TAP into a visible color change. The addition of dimethyl terephthalate and N,N-dimethyl-2-propyl-2-enyloxyethanolamine may help form a stable copolymer structure, improving signal conversion efficiency and thus reducing the false positive rate.

[0041] In summary, the test strips prepared in Examples 1-3 have good sensitivity and specificity.

[0042] In the description, reference to terms such as "making", "implementing", "embodiments", and the like means that the particular feature, structure, material, or characteristic being referred to is included in at least one embodiment of the present application. The illustrative examples described in this specification are not meant to be limiting. Also, well-known steps along with their

[0043] The above descriptions are only the preferred embodiments of the present application, not intended to limit the protection scope of the present application. Any modification, equivalent replacement or change made by any person skilled in the art within the technical scope disclosed by the present application and the inventive concept thereof should be covered within the protection scope of the present application.

Claims

1. A method for preparing a test strip for detecting abnormal sugar chains in tumors, characterized in that: The method comprises the following steps: Cut a nitrocellulose membrane and use it as a test paper base. Evenly coat the test complex solution on the test paper base and place it in a 37°C oven to dry for 2-3 hours. Add a standard solution of known concentration dropwise to one end of the test paper as a quality control line. Mark the reaction area on the test paper, seal it in an aluminum foil bag, and store it at 4°C in the dark to obtain a test paper for abnormal sugar chains in tumors. The detection complex solution includes a recognition element solution and a signal conversion element solution.

2. The method for preparing a test strip for detecting abnormal sugar chains in tumors according to claim 1, wherein: The detection complex solution is prepared by the following steps: S1. Add the aptamer or sugar-binding protein to phosphate buffer, add N-hydroxysuccinimide and 1-(3-dimethylaminopropyl)-3-ethylcarbodiimide, stir and react at room temperature for 2-3 hours, dialyze or centrifuge to obtain a recognition element solution; S2. In an oxygen-free and light-proof environment, silver nitrate is rapidly added to a solution containing 30-40% ascorbic acid, sodium citrate is added, and the mixture is heated and stirred until the solution turns yellow or light gray, and then cooled to room temperature to obtain a silver nanoparticle solution; S3, adding dimethyl terephthalate, ethylene glycol and tetrabutyl titanate to a reactor filled with methanol solvent, heating and stirring under nitrogen protection for 3-4 hours to obtain oligomers, continuing to add polyethylene glycol 200, heating and stirring for 4-6 hours, after the reaction is completed, distilling under reduced pressure, adding N,N-dimethyl-2-propyl-2-enyloxyethanolamine and azobisisobutyronitrile while hot, controlling the reaction temperature, stirring and reacting for 24-48 hours to obtain a copolymer solution, uniformly dispersing the silver nanoparticle solution in the copolymer solution, stirring for 1-2 hours, to obtain a signal conversion element solution; S4. Mix the recognition element solution and the signal conversion element solution, and incubate at room temperature for 1-2 hours to obtain a detection complex solution.

3. The method for preparing a test strip for detecting abnormal sugar chains in tumors according to claim 1, wherein: The area of ​​the test paper base is 5 cm × 1 cm, the standard solution is added dropwise to the 1 cm × 0.5 cm area of ​​the test paper, and the area of ​​the reaction zone is 2 cm × 1 cm.

4. The method for preparing a test strip for detecting abnormal sugar chains in tumors according to claim 2, wherein: In step S1, the mass ratio of the aptamer or sugar-binding protein, phosphate buffer, N-hydroxysuccinimide and 1-(3-dimethylaminopropyl)-3-ethylcarbodiimide is (1-2):10:(0.55-0.57):(0.48-0.52).

5. The method for preparing a test strip for detecting abnormal sugar chains in tumors according to claim 2, wherein: The mass ratio of silver nitrate, sodium citrate and ascorbic acid in step S2 is (1.5-1.8):(2-3):(8-10).

6. The method for preparing a test strip for detecting abnormal sugar chains in tumors according to claim 2, wherein: In step S2, the heating temperature is 90-100° C., the stirring speed is 50-100 rpm, and the reaction time is 20-30 min.

7. The method for preparing a test strip for detecting abnormal sugar chains in tumors according to claim 2, wherein: In step S3, the mass ratio of dimethyl terephthalate, ethylene glycol, tetrabutyl titanate, polyethylene glycol 200, N,N-dimethyl-2-propyl-2-enyloxyethanolamine and azobisisobutyronitrile is (2.5-3.3): (1-1.5): (0.1-0.3): (0.8-1): (0.7-0.8): (0.05-0.1), and the mass ratio of the copolymer solution to the silver nanoparticle solution is (1.8-2.2): (0.8-1).

8. The method for preparing a test strip for detecting abnormal sugar chains in tumors according to claim 2, wherein: In step S3, the heating temperature is 190-200° C., the rising temperature is 220-230° C., the reaction temperature is controlled to be 80-100° C., and the stirring speed is 50-100 rpm.

9. The method for preparing a test strip for detecting abnormal sugar chains in tumors according to claim 2, wherein: In step S4 , the mass ratio of the identification element solution to the signal conversion element solution is (1-1.2):(0.7-0.8).

10. A test strip for detecting abnormal sugar chains in tumors prepared by the method according to any one of claims 1 to 9.

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