A dry analytical reagent for total cholesterol detection

Abstract

A dry analytical reagent for total cholesterol detection comprises, from top to bottom, an upper supporting layer, a diffusion layer, a reagent layer, a support, and a lower supporting layer, wherein the diffusion layer, the reagent layer, and the support are sequentially arranged in a middle position between the upper supporting layer and the lower supporting layer, the pores at both ends of the upper supporting layer and the lower supporting layer are bonded by the middle supporting layer, and a sample addition hole and a test hole are respectively arranged in the middle position of the upper supporting layer and the lower supporting layer, the diffusion layer is an isotropic porous diffusion membrane with a porosity of 50-85%; the diffusion layer is composed of polystyrene microspheres, an adhesive, and a surfactant, and the particle size of the polystyrene microspheres is 0.1-1 μm; the reagent layer includes a surfactant, cholesterol esterase, cholesterol oxidase, horseradish peroxidase, a colorless dye, a buffer, a stabilizer, and a water-soluble high molecular polymer. The diffusion layer prepared by the present invention has a diffusion path of tens to hundreds of nanometers, which can quickly absorb, evenly distribute, measure, and quickly transmit multiple analytes.

Description

Technical Field

[0001] The invention relates to a dry analytical reagent for detecting total cholesterol, belonging to the field of clinical diagnosis. Background Art

[0002] With the development of social economy and the improvement of people's living standards, the prevalence of cardiovascular and cerebrovascular related chronic diseases has shown an upward trend, and is increasingly developing in the direction of younger people. Excessive total cholesterol levels in the human body are closely related to the occurrence of cardiovascular diseases, which can easily cause coronary heart disease and other atherosclerotic diseases. Regular preventive testing of cholesterol levels and immediate, accurate and rapid diagnosis can effectively prevent the occurrence and deterioration of cardiovascular diseases. There are two clinical methods for cholesterol detection: wet chemistry and dry chemistry. Among them, wet chemistry is suitable for use in scenarios where a large number of samples enter the central laboratory at one time. The reagents prepared at one time can be used to analyze a large number of clinical samples at the same time. However, with the outbreak of the new crown epidemic and the increase in the demand for emergency testing, the clinical report time for biochemical analysis has put forward shorter requirements, which has promoted the development of emergency biochemical testing technology from traditional wet chemistry to dry biochemistry. Unlike conventional wet chemical methods, dry chemical analysis methods have the advantages of fast detection speed, easy storage of detection reagents, no need to configure any liquid reagents, low detection threshold requirements, and strong adaptability to various occasions. According to the testing needs, personalized project combination testing can be performed on scattered samples anytime and anywhere. It is especially suitable for emergency, primary clinics, blood stations, physical examination institutions, testing laboratories and other scenarios.

[0003] Currently, the most commonly used dry analytical reagents are multilayer film dry films. This product inherits the coating technology of photosensitive film. Various required functional layers, such as a diffusion layer, a light-blocking layer, a reagent layer, and a reaction indicator layer, are coated sequentially or simultaneously on a transparent support. The sample loading hole is above the diffusion layer, and the test hole is on the back of the support. The concentration of the analyte is analyzed by measuring the change in reflected light density. This type of multilayer film dry film provides accurate test results, but the production process is complex. The production of the diffusion layer requires the use of multiple organic solvents, which generates a large amount of organic waste gas, which is harmful to the environment and increases the risk of the production process. Another type of dry chemical analytical reagent consists of a plastic support layer with a reaction zone at one end, including a sample layer and a reagent layer. The reagent layer uses fabric as a reagent carrier, and sample loading and testing are both performed on this layer.

[0004] Currently, commonly used dry chemical urine test strips and blood glucose analysis test strips provide relatively simple qualitative and semi-quantitative analysis, but are not capable of highly quantitative analysis. Patent No. 201911056555.7 discloses a dry chemical multi-layer membrane reagent for in vitro biochemical diagnosis. This method still uses a variety of organic solvents and produces a lot of organic waste gas that is harmful to the environment. Patent No. 201810050191.0 discloses a total cholesterol detection method, in which the blood filter membrane uses a commercially available product, the reaction layer is in the form of liquid soaking and drying, and the blood filter layer and reagent layer need to be made separately and then assembled, which only allows for semi-quantitative analysis, not quantitative analysis. Summary of the Invention

[0005] The present invention aims to overcome the drawbacks of the prior art and provides a dry analytical reagent for total cholesterol detection.

[0006] The technical solution adopted by the present invention to solve its technical problem is:

[0007] A dry analytical reagent for total cholesterol detection comprises, from top to bottom, an upper supporting layer, a diffusion layer, a reagent layer, a support body, and a lower supporting layer. The diffusion layer, reagent layer, and support body are sequentially arranged in a middle position between the upper supporting layer and the lower supporting layer. The pores at both ends of the upper supporting layer and the lower supporting layer are bonded together by the middle supporting layer. A sample addition hole and a test hole are respectively arranged in the middle position of the upper supporting layer and the lower supporting layer. The diffusion layer is an isotropic porous diffusion membrane with a porosity of 50-85%. The diffusion layer is composed of polystyrene microspheres, an adhesive, and a surfactant. The particle size of the polystyrene microspheres is 0.1-1 μm. The adhesive is concentrated in the area adjacent to adjacent microspheres on the surface of the polystyrene microspheres and bonds the polystyrene microspheres into a coherent three-dimensional lattice. The reagent layer comprises a surfactant, cholesterol esterase, cholesterol oxidase, horseradish peroxidase, a colorless dye, a buffer, a stabilizer, and a water-soluble high molecular polymer.

[0008] In the above-mentioned dry analytical reagent for total cholesterol detection, the polystyrene microsphere component is a homopolymer or copolymer of polystyrene.

[0009] The above-mentioned dry analytical reagent for total cholesterol detection, the component of the polystyrene microspheres is one of polystyrene, poly(styrene-methacrylic acid), poly(styrene-divinylbenzene), poly(styrene-butyl acrylate) or poly(styrene-hydroxyethyl methacrylate-divinylbenzene).

[0010] The above-mentioned dry analytical reagent for total cholesterol detection, the adhesive is one or more of pure acrylic emulsion or styrene acrylic emulsion, and the styrene acrylic emulsion is poly(butyl acrylate-styrene), poly(ethyl acrylate-styrene) or poly(vinyl toluene-tert-butylstyrene-methacrylic acid).

[0011] In the above-mentioned dry analytical reagent for total cholesterol detection, the amount of the polystyrene microspheres added per unit square meter is 20-500 g, and the amount of the adhesive added per unit square meter accounts for 2-10% of the amount of the polystyrene microspheres added per unit square meter.

[0012] In the above-mentioned dry analytical reagent for total cholesterol detection, the colorless dye is one of diarylimidazole dye, triarylimidazole dye and benzidine, preferably 3,3'-dimethoxybenzidine.

[0013] The above-mentioned dry analytical reagent for total cholesterol detection, the surfactant is a non-ionic surfactant, and the non-ionic surfactant is a chain structure composed of 8 to 15 interconnected ethylene oxide or propylene oxide groups, specifically alkylphenoxypolyethoxyethanol.

[0014] The above-mentioned dry analytical reagent for total cholesterol detection has a pH value of 5.5-9.0, and contains tris(hydroxymethyl)aminomethane (tris), phosphate, borate, citric acid or citrate, lysine, N,N-bis(2-hydroxyethyl)glycine, sodium salt or potassium salt of N-2-hydroxyethylpiperazine-N'-2-hydroxypropane-3-sulfonic acid, sodium salt or potassium salt of N-2-hydroxyethylpiperazine-N'-3-sulfonic acid, sodium salt or potassium salt of N-[tris(hydroxymethyl)methyl]-3-aminopropanesulfonic acid, sodium salt or potassium salt of N-2-hydroxyethylpiperazine-N'-2-ethanesulfonic acid, and one of the acids, bases or salts combined with any of the above compounds.

[0015] The above-mentioned dry analytical reagent for total cholesterol detection, the stabilizer is one or more of ascorbic acid oxidase, EDTA, polyethylene glycol, magnesium chloride, and sodium cholate; the water-soluble high molecular polymer is a mixture of one or more of gelatin, gelatin derivatives, agarose, dextran, polyvinyl alcohol, polyacrylamide, and hydrophilic cellulose derivatives.

[0016] The above-mentioned dry analytical reagent for total cholesterol detection, the upper support, lower support and intermediate support are all transparent plastic substrates with a transmittance of more than 80% under light of a wavelength of 200nm-900nm, including one of polyethylene terephthalate, polycarbonate, polypropylene and polyethylene, and their thickness is 50-300μm, preferably 100-200μm.

[0017] The beneficial effects of the present invention are:

[0018] The dry analytical reagent for total cholesterol detection of the present invention does not use organic solvents during the preparation process, and the production and preparation process is environmentally friendly. The diffusion layer is mainly composed of polystyrene microspheres and an adhesive. The particle size distribution of the polystyrene microspheres and the amount of adhesive added are controlled to form a diffusion path of tens to hundreds of nanometers. It can quickly absorb, evenly distribute, measure and quickly transmit multiple analytes such as ions, uric acid, creatinine, glucose and cholesterol, thereby analyzing substances to be tested with different molecular weight distributions and compositions in biological fluids. The test results are highly accurate and the measurement range is wide, meeting the needs of immediate diagnosis and on-site diagnosis, and has great clinical application value. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 This is a schematic diagram of the structure of the multi-layer dry chemical reagent sheet of the present invention;

[0020] Figure 2 The results of the analysis of the correlation between the method of the present invention and multiple test samples using the Abell-Kendall method in Example 1 are as follows;

[0021] Figure 3 The results of the analysis of the correlation between the method of the present invention and multiple test samples using the Abell-Kendall method in Example 2 are as follows;

[0022] Figure 4 This is the analysis result of the correlation between the method of the present invention and multiple test samples using the Abell-Kendall method in Example 3.

[0023] In the figure: 1, upper support layer; 1-1, sample addition hole; 2, diffusion layer; 3, reagent layer; 4, support body; 5, lower support layer; 5-1, test hole; 6, middle support layer. DETAILED DESCRIPTION

[0024] To make the objectives, technical solutions, and advantages of the embodiments of the present invention more clear, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the accompanying drawings of the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. All other embodiments obtained by ordinary technicians in this field based on the embodiments of the present invention without making any creative efforts shall fall within the scope of protection of the present invention.

[0025] The dry analytical reagent for total cholesterol detection of the present invention can measure total cholesterol in a body fluid sample. The body fluid may be blood or urine. The body fluid sample may be blood or urine directly or may be a sample that has been appropriately pretreated.

[0026] The dry analytical reagent for total cholesterol detection of the present invention includes, from top to bottom, an upper support layer 1, a diffusion layer 2, a reagent layer 3, a support body 4 and a lower support layer 5. The diffusion layer, the reagent layer and the support body are arranged in the middle position between the upper support layer and the lower support layer, and the pores at both ends of the upper support layer and the lower support layer are bonded by the middle support layer 6. The middle position of the upper support layer 1 and the lower support layer 5 is respectively provided with a sample addition hole 1-1 and a test hole 5-1. The reagent layer and the diffusion layer distributed on the support body are structural layers for the sample to be tested to be added and diffused to generate biochemical reactions. The support body layer is a structural layer that plays a supporting role and is a light-transmitting carrier. The upper support layer, the lower support layer and the middle support layer are inner packaging structures that play a role of fixing and protecting the support body on which the reagent layer and the diffusion layer are distributed.

[0027] The diffusion layer is an isotropic porous diffusion membrane with a porosity of 50-85%. The diffusion layer is composed of polystyrene microspheres, an adhesive and a surfactant. The particle size of the polystyrene microspheres is 0.1-1 μm. The adhesive is concentrated in the area adjacent to the adjacent microspheres on the surface of the polystyrene microspheres and bonds the polystyrene microspheres into a coherent three-dimensional lattice to form a high-porosity structure, so that the diffusion layer has the function of efficiently diffusing liquids containing analytes of different molecular weights. It can evenly distribute, diffuse and quickly transfer samples to be tested containing multiple analytes inside, and make the samples to be tested Small molecules such as water, ions, uric acid, creatinine, glucose, and cholesterol in the liquid diffuse and transfer into the reagent layer in the form of a fluid. The amount of polystyrene microspheres added per unit square meter is 20-500 g, preferably 50-300 g, and the amount of the adhesive added per unit square meter accounts for 2-10% of the amount of the polystyrene microspheres added per unit square meter. This controls the formation of an isotropic porous diffusion layer with different porosities and pore size distributions, which is used for rapid absorption, uniform distribution, metering, and rapid transmission of multiple analytes, thereby analyzing substances to be tested with different molecular weight distributions and compositions in biological fluids.

[0028] The total cholesterol to be detected in the present invention is a small biological molecule. The diffusion layer with a nanometer to submicron pore size distribution and a high porosity structure can meet the needs of rapid distribution and isotropic transmission of the sample to be tested, thereby providing a basis for subsequent precise reaction and detection functions. The present invention adopts soap-free emulsion polymerization technology to synthesize submicron polystyrene microspheres, avoiding the addition of organic solvents such as emulsifiers. The prepared polystyrene microspheres have high purity, uniform particle size, good monodispersity, and can be prepared into functional microspheres with different modifications through copolymerization of monomers. During the preparation of the diffusion layer, a three-dimensional lattice structure with polystyrene microspheres as the lattice center is formed by controlling the amount of adhesive added and the preparation process. The tightly arranged three-dimensional lattice structure constitutes a transmission channel for the rapid distribution of biological fluids.

[0029] The reagent layer 3 includes a surfactant, cholesterol esterase, cholesterol oxidase, peroxidase, a colorless dye, a buffer, a stabilizer, and a water-soluble polymer. The colorless dye (chromogenic substrate) is 3,3'-dimethoxybenzidine. It can specifically bind to hydrogen peroxide generated by the enzyme-linked reaction in an equal molar ratio (1:1), generating a high-density concentration of a chromogenic substance, thereby improving the accuracy of total cholesterol detection. Conventional total cholesterol detection kits generally use the Trinder reaction reagent as a chromogenic substrate for detecting the content of hydrogen peroxide produced by the enzyme-catalyzed reaction of total cholesterol. However, the Trinder reaction reagent has disadvantages such as a high detection limit, poor substrate specificity, and low color density. For every 2 mol of hydrogen peroxide generated by the catalytic reaction, a maximum of 1 mol of a red quinoneimine compound is generated. Furthermore, substances such as vitamin C, uric acid, glutathione, various drugs, and bilirubin will compete with the chromogenic substrate for the hydrogen peroxide generated by the catalytic reaction, resulting in the inability of hydrogen peroxide to specifically bind to the chromogenic substrate, resulting in inaccurate detection results. The 3,3'-dimethoxybenzidine of the present invention has better specificity than Trinder, thereby improving the specificity and accuracy of the determination.

[0030] The surfactant in the reagent layer is commercially available from Rohm and Haas Co. under the Triton trademark (X-100, 102, 165, 305 and 405 are particularly useful), preferably Triton X-100, and is added in an amount of 1-25 g per square meter, more preferably 2-15 g per square meter.

[0031] There is no limitation on the sources of cholesterol esterase, cholesterol oxidase and peroxidase in the reagent layer, and the usage amounts are 2-100 KU, 0.2-50 KU, 2-100 KU per square meter, preferably 5-20 KU, 0.5-20 KU, 5-20 KU per square meter.

[0032] The buffer in the reagent layer is preferably a phosphate buffer or a tris buffer. The pH value of the buffer is determined according to the activity range of the enzyme used and is adjusted to pH 5.0-8.0, preferably 6.0-7.0.

[0033] The stabilizers in the reagent layer are preferably EDTA and polyethylene glycol, and the usage amounts are 0.05-5 g and 0.5-20 g per square meter, preferably 0.1-2.5 g and 1-10 g per square meter.

[0034] The water-soluble high molecular polymer in the reagent layer is preferably gelatin, and the usage amount is 1-50 g per square meter, preferably 2-25 g per square meter.

[0035] Preparation method of the present invention:

[0036] (1) Reagent Layer: The reagent solution is coated on the support. The coating method can use a known method, preferably wire rod coating, blade coating, or extrusion coating. The wet film thickness of the reagent layer is preferably 50-500 μm. After drying at 10°C-60°C, the dry film thickness of the reagent layer is preferably 5-50 μm.

[0037] (2) The diffusion layer slurry is coated on the reagent layer (1). The coating method can use a known method, preferably wire rod coating, blade coating, and extrusion coating. The wet film thickness of the diffusion layer is preferably 60-600 μm. After drying at 10°C-60°C, the dry film thickness of the diffusion layer is preferably 20-200 μm.

[0038] (3) Cut the material prepared in step (2) into 1.2cm 2 The small pieces are fixed and assembled into dry analytical reagents using customized white PET plastic sheets as the upper support layer, lower support layer and middle support layer.

[0039] The total cholesterol detection method of the present invention is as follows:

[0040] Approximately 5 μL to 25 μL of the test liquid is added to the homogeneous porous diffusion layer and incubated at a constant temperature of approximately 25°C to 50°C for 1 to 15 minutes. The test liquid rapidly diffuses uniformly in all directions through the diffusion layer and longitudinally into the reagent layer, forming a uniform concentration distribution. Total cholesterol is separated from lipoprotein complexes by the surfactant TRITON X-100. Free total cholesterol is catalyzed by cholesterol esterase and cholesterol oxidase to produce hydrogen peroxide. Hydrogen peroxide reacts with a colorless dye under the catalysis of peroxidase to form a complex of a specific color. The color change reaction produced by the dry analytical reagent is measured by reflection density from the support side, and the total cholesterol concentration in the test liquid is calculated using a pre-prepared calibration curve. The reaction equation for the target substance, total cholesterol, with the corresponding substance in the dry analytical reagent is as follows:

[0041]

[0042] The dry analytical reagent for total cholesterol detection of the present invention does not require an organic solvent in its preparation process and is environmentally friendly. The dry analytical reagent has good stability, is easy to store and preserve, has high detection accuracy, and has a wide linear range.

[0043] The present invention will be further described below with reference to the embodiments.

[0044] Example 1

[0045] The reagent layer coating solution of Table 1 below was applied to a colorless, transparent, 175 μm PET film support 4 and dried at 40°C to a thickness of 15 μm after drying. Next, the diffusion layer coating solution of Table 2 below was applied to the above coating and dried at 35°C to a thickness of 100 μm after drying. After drying, the film was cut into 1.2 cm pieces. 2 Then use white PET plastic sheets as the upper support layer 1, the lower support layer 5 and the middle support layer 6. After assembly, it can be used for measurement.

[0046] Table 1 Reagent layer formula

[0047] Reagents <![CDATA[Coating amount / m 2 > gelatin 10g Triton X-100 8g Cholesterol esterase 15kU Cholesterol oxidase 4KU Peroxidase 6.4KU 3,3'-Dimethoxybenzidine 0.64g Tris buffer pH 7.0 EDTA 0.7g polyethylene glycol 3.6g

[0048] Table 2 Diffusion layer formula

[0049] Material <![CDATA[Coating amount / m 2 > Carboxyl modified polystyrene microspheres (0.2 μm) 150g Poly(butyl acrylate-styrene) emulsion 3g surfactants 1.5g

[0050] For 50 clinical serum samples, the correlation between the method of the present invention and the Abell-Kendall method was analyzed for multiple test samples. Figure 2 As shown, the present invention can obtain good correlation when compared with the benchmark reference method.

[0051] Example 2

[0052] The reagent layer coating solution of Table 3 below was applied to a colorless, transparent, 175 μm PET film support 4 and dried at 37°C to a thickness of 10 μm after drying. Next, the diffusion layer coating solution of Table 4 below was applied to the above coating and dried at 40°C to a thickness of 150 μm after drying. After drying, the film was cut into 1.2 cm pieces. 2 Then use white PET plastic sheets as the upper support layer 1, the lower support layer 5 and the middle support layer 6. After assembly, it can be used for measurement.

[0053] Table 3 Reagent layer formula

[0054] Reagents <![CDATA[Coating amount / m 2 > gelatin 5g Triton X-100 8g Cholesterol esterase 15kU Cholesterol oxidase 4KU Peroxidase 6.4KU 3,3'-Dimethoxybenzidine 0.64g Phosphate buffer pH 7.6 EDTA 0.7g polyethylene glycol 3.6g

[0055] Table 4 Diffusion layer formula

[0056] Material <![CDATA[Coating amount / m 2 > Polystyrene microspheres (0.5 μm) 100g Poly(butyl acrylate-styrene) emulsion 1.5g surfactants 1g

[0057] For 50 clinical serum samples, the correlation between the method of the present invention and the Abell-Kendall method was analyzed for multiple test samples. Figure 3 As shown, the present invention can obtain good correlation when compared with the benchmark reference method.

[0058] Example 3

[0059] The reagent layer coating solution of Table 5 below was applied to a colorless, transparent, 175 μm PET film support 4 and dried at 40°C to a thickness of 20 μm after drying. Next, the diffusion layer coating solution of Table 6 below was applied to the above coating and dried at 45°C to a thickness of 100 μm after drying. After drying, the film was cut into 1.2 cm pieces. 2 Then use white PET plastic sheets as the upper support layer 1, the lower support layer 5 and the middle support layer 6. After assembly, it can be used for measurement.

[0060] Table 5 Reagent layer formula

[0061] Reagents <![CDATA[Coating amount / m 2 > gelatin 15g Triton X-100 8g Cholesterol esterase 15kU Cholesterol oxidase 4KU Peroxidase 6.4KU 3,3'-Dimethoxybenzidine 0.64g Phosphate buffer pH 6.8 EDTA 0.7g polyethylene glycol 3.6g

[0062] Table 6 Diffusion layer formula

[0063] Material <![CDATA[Coating amount / m 2 > Carboxyl modified polystyrene microspheres (0.8 μm) 150g Poly(butyl acrylate-styrene) emulsion 4g surfactants 2g

[0064] For 50 clinical serum samples, the correlation between the method of the present invention and the Abell-Kendall method was analyzed for multiple test samples. Figure 4 As shown, the present invention can obtain good correlation when compared with the benchmark reference method.

[0065] The above embodiments are intended only to illustrate the technical concepts and features of the present invention. Their purpose is to enable those skilled in the art to understand the present invention and act accordingly. They are not intended to limit the scope of protection of the present invention. Any equivalent substitutions or improvements based on the essence of the present invention are intended to be included within the scope of the claims.

Claims

1. A dry analytical reagent for total cholesterol detection, the dry analytical reagent comprising, from top to bottom, an upper support layer (1), a diffusion layer (2), a reagent layer (3), a support body (4) and a lower support layer (5), the diffusion layer, the reagent layer and the support body being arranged in a middle position between the upper support layer and the lower support layer, the pores at both ends of the upper support layer and the lower support layer being bonded by an intermediate support layer (6), a sample addition hole (1-1) and a test hole (5-1) being respectively arranged in the middle position of the upper support layer (1) and the lower support layer (5), characterized in that: The diffusion layer is an isotropic porous diffusion membrane with a porosity of 50-85%. The diffusion layer is composed of polystyrene microspheres, an adhesive and a surfactant. The particle size of the polystyrene microspheres is 0.1-1 μm. The adhesive is concentrated in the area adjacent to the adjacent microspheres on the surface of the polystyrene microspheres and bonds the polystyrene microspheres into a coherent three-dimensional lattice. The reagent layer (3) includes a surfactant, cholesterol esterase, cholesterol oxidase, horseradish peroxidase, a colorless dye, a buffer, a stabilizer and a water-soluble high molecular polymer. The amount of the polystyrene microspheres added per unit square meter is 20-500 g, and the amount of the adhesive added per unit square meter accounts for 2-10% of the amount of the polystyrene microspheres added per unit square meter; The colorless dye is 3,3'-dimethoxybenzidine; The adhesive is one or more of pure acrylic emulsion or styrene acrylic emulsion, and the styrene acrylic emulsion is poly(butyl acrylate-styrene), poly(ethyl acrylate-styrene) or poly(vinyl toluene-tert-butyl styrene-methacrylic acid).

2. The dry analytical reagent for total cholesterol detection according to claim 1, wherein: The polystyrene microsphere component is a homopolymer or copolymer of polystyrene.

3. The dry analytical reagent for total cholesterol detection according to claim 2, wherein: The component of the polystyrene microspheres is one of polystyrene, poly(styrene-methacrylic acid), poly(styrene-divinylbenzene), poly(styrene-butyl acrylate) or poly(styrene-hydroxyethyl methacrylate-divinylbenzene).

4. The dry analytical reagent for total cholesterol detection according to claim 3, wherein: The surfactant is a nonionic surfactant having a chain structure consisting of 8 to 15 interconnected oxyethylene or oxypropylene groups, specifically alkylphenoxypolyethoxyethanol.

5. The dry analytical reagent for total cholesterol detection according to claim 4, wherein: The pH value of the buffer solution is 5.5-9.0, and the buffer solution contains tris(hydroxymethyl)aminomethane (tris), phosphate, borate, citric acid or citrate, lysine, N, N-bis(2-hydroxyethyl)glycine, sodium salt or potassium salt of N-2-hydroxyethylpiperazine-N'-2-hydroxypropane-3-sulfonic acid, sodium salt or potassium salt of N-2-hydroxyethylpiperazine-N'-3-sulfonic acid, sodium salt or potassium salt of N-[tris(hydroxymethyl)methyl]-3-aminopropanesulfonic acid, sodium salt or potassium salt of N-2-hydroxyethylpiperazine-N'-2-ethanesulfonic acid, and one of the acids, bases or salts combined with any of the above compounds.

6. The dry analytical reagent for total cholesterol detection according to claim 5, wherein: The stabilizer is one or more of ascorbic acid oxidase, EDTA, polyethylene glycol, magnesium chloride, and sodium cholate; the water-soluble high molecular polymer is a mixture of one or more of gelatin, gelatin derivatives, agarose, dextran, polyvinyl alcohol, polyacrylamide, and hydrophilic cellulose derivatives.

7. The dry analytical reagent for total cholesterol detection according to claim 6, wherein: The upper support, lower support and middle support are all transparent plastic substrates with a transmittance of more than 80% under light of 200nm-900nm wavelength, including one of polyethylene terephthalate, polycarbonate, polypropylene and polyethylene, and have a thickness of 50-300μm.

8. The dry analytical reagent for total cholesterol detection according to claim 7, wherein: The thickness of the upper support, the lower support and the middle support is 100-200 μm.

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