A dry analytical reagent for detecting γ-glutamyl transpeptidase

Abstract

A kind of γ-glutamyl transpeptidase detection dry analytical reagent, comprises an upper supporting layer, a diffusion layer, a reagent layer, a support and a lower supporting layer from top to bottom, the diffusion layer, the reagent layer and the support are arranged in the middle position between the upper supporting layer and the lower supporting layer from top to bottom, the two end pores of the upper supporting layer and the lower supporting layer are bonded by the middle supporting layer, the upper supporting layer and the lower supporting layer middle position are respectively provided with a sample addition hole and a test hole, and the diffusion layer porosity is 40 75%; the diffusion layer is composed of highly cross-linked polymethyl methacrylate microspheres, an adhesive and a surfactant, and the particle diameter of the highly cross-linked polymethyl methacrylate microspheres is 5 50 μm; the reagent layer includes a surfactant, diglycine, L γ-glutamyl 3-carboxyl p-nitroaniline, a buffer, a stabilizer and a water-soluble high molecular polymer. The diffusion layer of the present invention has the characteristic of isotropy, good detection specificity, high accuracy, wide measurement range, meets instant diagnosis, and has a large clinical application value.

Description

Technical Field

[0001] The invention relates to a dry analytical reagent for detecting gamma-glutamyl transpeptidase, and belongs to the field of clinical diagnosis. Background Art

[0002] γ-Glutamyltransferase (GGT) is a peptidase that catalyzes the γ-glutamyl transfer reaction. Serum GGT is a sensitive indicator of hepatobiliary disease, and elevated serum GGT levels can be seen in hepatobiliary diseases caused by various causes. Clinical testing for GGT can be performed using either wet chemistry or dry chemistry methods. Wet chemistry is the most commonly used analytical method, but it requires a long reagent preparation cycle, requires specialized personnel, and results are easily affected by operator skill. Dry chemistry, on the other hand, offers advantages such as rapid testing, easy storage of reagents, the absence of any liquid reagents, a low threshold for testing, and strong adaptability. With the increasing demand for emergency testing, clinical requirements for shorter biochemical analysis reporting times are being met, driving the gradual shift from traditional wet chemistry to dry chemistry in emergency biochemical testing. Dry chemistry offers rapid testing, a high level of automation, and the ability to perform personalized, integrated testing on individual samples anytime, anywhere. It is particularly suitable for emergency departments, primary care clinics, blood banks, physical examination institutions, and testing laboratories.

[0003] Currently, commonly used dry analytical reagents utilize the same coating technology used for photographic film: a diffusion layer, light-blocking layer, and reagent layer are sequentially coated onto a support. The concentration of the analyte is analyzed by measuring changes in reflected light density. While these multilayer film dry films offer accurate test results, the production process is complex. The diffusion layer requires the use of multiple organic solvents, generating significant amounts of organic waste gas, which is environmentally harmful 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 utilizes fabric as a reagent carrier, and sample loading and testing are performed on top of this layer.

[0004] Patent CN201910219761.9 discloses an automated blood filtration dry-type photochemical microchannel liver function test card. The blood filtration membrane uses a commercially available product and is tested using transmission photometry, which cannot completely avoid interference from substances in the sample. Patent CN201910236059.3 discloses a reagent and diagnostic analysis method for measuring γ-glutamyl transferase. The diagnostic analysis method is complex and requires specialized expertise. Furthermore, the precision of the test results from the microfluidic chip cannot be guaranteed. Summary of the Invention

[0005] In order to overcome the drawbacks of the prior art, the present invention provides a dry analytical reagent for detecting γ-glutamyl transpeptidase. The diffusion layer is made of highly cross-linked polymethyl methacrylate microspheres that do not swell and penetrate when exposed to water. The microspheres are combined with a very small amount of a specific adhesive to form a diffusion layer with a high-porosity structure. The diffusion layer can achieve efficient and rapid penetration and diffusion of the liquid to be analyzed containing γ-glutamyl transpeptidase, and can evenly distribute, diffuse and quickly transfer the sample to be analyzed containing the analyte inside.

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

[0007] A dry analytical reagent for detecting γ-glutamyl transpeptidase, the dry analytical reagent comprising, from top to bottom, an upper support layer, a diffusion layer, a reagent layer, a support body, and a lower support layer, wherein the diffusion layer, the reagent layer, and the support body are sequentially 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 are bonded by the middle support layer, a sample addition hole and a test hole are respectively arranged in the middle position of the upper support layer and the lower support layer, the diffusion layer is an isotropic porous diffusion membrane with a porosity of 4 0-75%; the diffusion layer is composed of highly cross-linked polymethyl methacrylate microspheres, an adhesive, and a surfactant, wherein the particle size of the highly cross-linked polymethyl methacrylate microspheres is 5-50 μm, and the adhesive is concentrated in the area adjacent to the adjacent microspheres on the surface of the highly cross-linked polymethyl methacrylate microspheres and adheres the highly cross-linked polymethyl methacrylate microspheres into a coherent three-dimensional lattice; the reagent layer includes a surfactant, diglycerin, L-γ-glutamyl-3-carboxyl-p-nitroaniline, a buffer, a stabilizer, and a water-soluble high molecular polymer.

[0008] The above-mentioned dry analytical reagent for γ-glutamyl transpeptidase detection, the highly cross-linked polymethyl methacrylate microspheres are prepared by suspension polymerization, the cross-linking agent is selected from one or a combination of any two or more of methacrylate, ethylene glycol dimethacrylate, amino ester, divinylbenzene and N,N-methylenebisacrylamide, and the mass of the cross-linking agent accounts for 5wt% to 30wt% of the mass of the methyl methacrylate MMA monomer.

[0009] The dry analytical reagent for detecting γ-glutamyl transpeptidase mentioned above, wherein the binder includes one of poly(butyl acrylate-styrene), poly(n-butyl acrylate-acrylic acid), polyethyl acrylate, poly(N-isopropylacrylamide), poly(ethyl acrylate-styrene), poly(butyl acrylate-methacrylic acid), polyn-butyl methacrylate, poly(methyl methacrylate-butyl acrylate) or poly(vinyl toluene-tert-butylstyrene-methacrylic acid).

[0010] The dry analytical reagent for detecting γ-glutamyl transpeptidase is used, wherein the amount of the highly cross-linked polymethyl methacrylate microspheres added per square meter is 20-500 g, and the amount of the adhesive added per square meter accounts for 1.5-4.5% of the amount of the highly cross-linked polymethyl methacrylate microspheres added per square meter.

[0011] In the above-mentioned dry analytical reagent for detecting γ-glutamyl transpeptidase, the surfactant is a nonionic surfactant, including one of 4-octylphenoxy polyoxyethylene ether, 4-nonylphenoxy polyoxyethylene ether, polyoxyethylene sorbitan monolaurate or octyl glucoside.

[0012] In the dry analytical reagent for detecting γ-glutamyl transpeptidase, the surfactant is preferably a nonionic surfactant having a chain structure consisting of 8 to 15 interconnected ethylene oxide or propylene oxide groups.

[0013] The dry analytical reagent for detecting γ-glutamyl transpeptidase comprises a buffer having a pH value within the range of 7.0 to 9.0, and comprising tris(hydroxymethyl)aminomethane (tris), phosphate, borate, lysine, N,N-bis(2-hydroxyethyl)glycine, sodium or potassium salt of N-2-hydroxyethylpiperazine-N'-2-hydroxypropane-3-sulfonic acid, sodium or potassium salt of N-2-hydroxyethylpiperazine-N'-3-sulfonic acid, sodium or potassium salt of N-[tris(hydroxymethyl)methyl]-3-aminopropanesulfonic acid, sodium or potassium salt of N-2-hydroxyethylpiperazine-N'-2-ethanesulfonic acid, sodium or potassium salt of 1,4-piperazine-diethanesulfonic acid (PIPES), and one of an acid, base, or salt combined with any of the above compounds.

[0014] In the above-mentioned dry analytical reagent for detecting γ-glutamyl transpeptidase, the stabilizer is one or more polysaccharides or disaccharides; and 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.

[0015] The above-mentioned dry analytical reagent for detecting γ-glutamyl transpeptidase, the upper support, the lower support and the 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.

[0016] The beneficial effects of the present invention are:

[0017] The dry analytical reagent for detecting γ-glutamyl transpeptidase of the present invention does not use organic solvents during its preparation, and the production and preparation process is environmentally friendly. The diffusion layer uses highly cross-linked polymethyl methacrylate microspheres that are non-swelling and non-permeable when exposed to water, which are combined with a very small amount of a specific adhesive to form a diffusion layer with a high-porosity structure. The liquid to be analyzed containing γ-glutamyl transpeptidase can be efficiently and quickly penetrated and diffused, and the liquid can be uniformly distributed, diffused, and quickly transferred inside the sample to be analyzed containing the analyte. L-γ-glutamyl-3-carboxyl-p-nitroaniline with good water solubility is used as a chromogenic substrate, and the test results have high accuracy and a wide measurement range, meeting the needs of instant diagnosis and on-site diagnosis, and having great clinical application value. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 This is a schematic diagram of the structure of the multi-layer dry chemical reagent sheet of the present invention;

[0019] Figure 2 This is an analysis diagram of the correlation between the method of the present invention in Example 1 and a plurality of test samples using the γ-glutamylcarboxynitroaniline control method;

[0020] Figure 3 This is an analysis diagram of the correlation between the method of the present invention and the γ-glutamylcarboxynitroaniline control method for multiple test samples in Example 2;

[0021] Figure 4 This is an analysis diagram of the correlation between the method of the present invention in Example 3 and a plurality of test samples using the γ-glutamylcarboxynitroaniline control method.

[0022] 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

[0023] 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.

[0024] The dry analytical reagent of the present invention can measure γ-glutamyl transpeptidase in body fluid samples. The body fluid can be blood or urine. The body fluid sample can be blood or urine directly or a sample that has been appropriately pretreated.

[0025] The dry analytical reagent of the present invention comprises, 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 in sequence from top to bottom. The pores at both ends of the upper support layer and the lower support layer are bonded by the middle support layer 6. A sample addition hole 1-1 and a test hole 5-1 are respectively provided in the middle position of the upper support layer 1 and the lower support layer 5. The liquid to be tested is dripped onto the diffusion layer through the sample addition hole. The liquid to be tested quickly and evenly diffuses in all directions through the diffusion layer while diffusing longitudinally toward the reagent layer, generating a biochemical reaction in the reagent layer. The support body is a structural layer that serves as a supporting and light-transmitting carrier. The upper support layer, the lower support layer and the middle support layer are inner packaging structures that serve to fix and protect the support body on which the reagent layer and the diffusion layer are distributed.

[0026] The diffusion layer of the present invention uses highly cross-linked polymethyl methacrylate microspheres that are non-swelling and non-permeable when exposed to water, and is combined with a very small amount of a specific adhesive to form a diffusion layer with a high porosity structure. The adhesive is concentrated on the surface of the highly cross-linked polymethyl methacrylate microspheres and in the adjacent areas of adjacent microspheres, bonding the highly cross-linked polymethyl methacrylate microspheres into a coherent three-dimensional lattice. This three-dimensional lattice structure exhibits a high void volume. By controlling the particle size distribution of the highly cross-linked polymethyl methacrylate microspheres and the amount of adhesive added, various uniform porous diffusion layers with different porosities and pore size distributions are formed. The diffusion layer is used for rapidly absorbing, uniformly distributing, metering, and rapidly transmitting multiple analytes, thereby analyzing substances to be tested with different molecular weight distributions and compositions in biological fluids.

[0027] The highly cross-linked polymethyl methacrylate microspheres of the present invention are prepared by suspension polymerization technology. In order to meet the requirements of non-swelling and non-permeability of the polymer microspheres, an appropriate cross-linking agent needs to be added during the microsphere polymerization to obtain a high-strength cross-linked structure. The cross-linking agent in the present invention is preferably divinylbenzene, and the amount of the cross-linking agent added is preferably 5wt% to 2wt% of the weight of the methyl methacrylate (MMA) monomer. The particle size of the highly cross-linked polymethyl methacrylate microspheres is controlled to be 5-50 μm by controlling the reaction time, and the amount added per unit square meter is 20-500 g, preferably 50-300 g. The amount of the binder added per unit square meter accounts for 1.5-4.5% of the amount of the highly cross-linked polymethyl methacrylate microspheres. The porosity of the diffusion layer is controlled to be 40-75%, and a large number of diffusion paths ranging from hundreds of nanometers to several micrometers can be formed. The relative molecular mass of γ-glutamyl transpeptidase is about 90 kDa, and the molecular size is about tens of nanometers. The diffusion paths of the diffusion layer can allow water, small molecules and γ-glutamyl transpeptidase to pass through the diffusion paths. Glutamyl transpeptidase rapidly distributes, measures and transports, and prevents the passage of macromolecules such as red blood cells, thus forming an effective filtering effect.

[0028] The chromogenic substrate in the reagent layer of the present invention is selected from L-γ-glutamyl-3-carboxyl-p-nitroaniline with good water solubility. The commonly used γ-glutamyl transpeptidase detection kits now basically all adopt L-γ-glutamyl-p-nitroaniline as the chromogenic substrate, but L-γ-glutamyl-p-nitroaniline has the disadvantages of poor water solubility and low color density, making it difficult to reach saturated substrate concentration and unable to show the maximum activity of L-γ-glutamyl transferase. After screening, the present invention uses L-γ-glutamyl-3-carboxyl-p-nitroaniline, a substrate with good water solubility, as the chromogenic substrate. The amount of L-γ-glutamyl-3-carboxyl-p-nitroaniline added per unit square meter is 0.01-1g, preferably 0.02-0.5g per unit square meter.

[0029] The amount of surfactant added to the reagent layer is 1-25g per unit square meter, preferably 2-15g per unit square meter; the amount of diglycine added per unit square meter is 0.1-10g per unit square meter, preferably 0.2-5g per unit square meter; the amount of stabilizer added per unit square meter is 0.2-10g; the amount of water-soluble high molecular polymer added per unit square meter is 1-50g per unit square meter, preferably 2-25g per unit square meter.

[0030] The preparation method of the dry analytical reagent of the present invention is specifically as follows:

[0031] (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.

[0032] (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, extrusion coating, and the diffusion layer wet film thickness is preferably 60-600 μm. After drying at 10°C-60°C, the diffusion layer dry film thickness is preferably 20-200 μm.

[0033] (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.

[0034] The dry analytical reagent detection method for γ-glutamyl transpeptidase of the present invention is as follows:

[0035] Approximately 10 μL of the test liquid is dripped onto the porous diffusion layer of uniform properties and incubated at approximately 37°C for 5 minutes. The test liquid rapidly diffuses uniformly in all directions through the diffusion layer while also diffusing longitudinally toward the reagent layer, forming a uniform concentration distribution. GGT catalyzes the transfer of the glutamate portion of L-γ-glutamyl-p-nitroaniline to glycine, while simultaneously generating p-nitroaniline. The color change reaction produced by the dry analytical reagent is detected by reflection density from the support side using a rate method, and the concentration of GGT in the test liquid is calculated using a pre-made calibration curve. The equation for the reaction of the target substance GGT with the corresponding substance in the dry analytical reagent is as follows:

[0036]

[0037] The dry analytical reagent for detecting gamma-glutamyl transpeptidase 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.

[0038] The present invention will be further described below with reference to the embodiments.

[0039] Example 1

[0040] 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.

[0041] Table 1 Reagent layer formula

[0042] Reagents <![CDATA[Coating amount / m 2 <!-- 4 -->]]> gelatin 10g Glycine 1.8g L-γ-glutamyl-3-carboxy-p-nitroaniline 200mg PIPES buffer pH 7.7 Triton X-100 1.5g sucrose 1.2g

[0043] Table 2 Diffusion layer formula

[0044] Material <![CDATA[Coating amount / m 2 > Highly cross-linked polymethyl methacrylate microspheres (10 μm) 150g Poly(n-butyl acrylate-acrylic acid) emulsion 3g surfactants 1.5g

[0045] For 25 clinical serum samples, the correlation between the method of the present invention and the modified γ-glutamyl carboxynitroaniline control 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.

[0046] Example 2

[0047] 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.

[0048] Table 3 Reagent layer formula

[0049] Reagents <![CDATA[Coating amount / m 2 > gelatin 10g Glycine 3.5g L-γ-glutamyl-3-carboxy-p-nitroaniline 150mg PIPES buffer pH8.0 Triton X-100 1.5g sucrose 2.0g

[0050] Table 4 Diffusion layer formula

[0051] Material <![CDATA[Coating amount / m 2 > Highly cross-linked polymethyl methacrylate microspheres (30 μm) 100g Poly(butyl acrylate-styrene) emulsion 1.5g surfactants 1g

[0052] For 25 clinical serum samples, the correlation between the method of the present invention and the modified γ-glutamyl carboxynitroaniline control 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.

[0053] Example 3

[0054] 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.

[0055] Table 5 Reagent layer formula

[0056] Reagents <![CDATA[Coating amount / m 2 > gelatin 10g Glycine 1.0g L-γ-glutamyl-3-carboxy-p-nitroaniline 100mg Tris buffer pH7.8 Triton X-100 1.5g sucrose 0.6g

[0057] Table 6 Diffusion layer formula

[0058] Material <![CDATA[Coating amount / m 2 > Highly cross-linked polymethyl methacrylate microspheres (45 μm) 150g Poly(butyl acrylate-methacrylic acid) emulsion 4g surfactants 2g

[0059] For 25 clinical serum samples, the correlation between the method of the present invention and the modified γ-glutamyl carboxynitroaniline control 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.

[0060] 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 of the present invention.

Claims

1. A dry analytical reagent for detecting γ-glutamyl transpeptidase, 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 40-75%. The diffusion layer is composed of highly cross-linked polymethyl methacrylate microspheres, an adhesive and a surfactant. The particle size of the highly cross-linked polymethyl methacrylate microspheres is 5-50 μm. The adhesive is concentrated in the area adjacent to the adjacent microspheres on the surface of the highly cross-linked polymethyl methacrylate microspheres and bonds the highly cross-linked polymethyl methacrylate microspheres into a coherent three-dimensional lattice. The reagent layer (3) includes a surfactant, diglycerin, L-γ-glutamyl-3-carboxyl-p-nitroaniline, a buffer, a stabilizer and a water-soluble polymer. The highly cross-linked polymethyl methacrylate microspheres are prepared by suspension polymerization, and the cross-linking agent is selected from one or a combination of any two or more of methacrylate, ethylene glycol dimethacrylate, amino, divinylbenzene and N,N-methylenebisacrylamide, and the weight of the cross-linking agent accounts for 5wt% to 30wt% of the weight of the methyl methacrylate (MMA) monomer. The binder comprises one of poly(butyl acrylate-styrene), poly(n-butyl acrylate-acrylic acid), polyethyl acrylate, poly(N-isopropylacrylamide), poly(ethyl acrylate-styrene), poly(butyl acrylate-methacrylic acid), poly(n-butyl methacrylate), poly(methyl methacrylate-butyl acrylate) or poly(vinyl toluene-tert-butylstyrene-methacrylic acid); The amount of the highly cross-linked polymethyl methacrylate microspheres added per unit square meter is 20-500 g, and the amount of the adhesive added per unit square meter accounts for 1.5-4.5% of the amount of the highly cross-linked polymethyl methacrylate microspheres added per unit square meter.

2. The dry analytical reagent for detecting γ-glutamyl transpeptidase according to claim 1, wherein: The surfactant is a nonionic surfactant, including one of octylphenoxy polyoxyethylene ether, nonylphenoxy polyoxyethylene ether, polyoxyethylene sorbitan monolaurate or octyl glucoside.

3. The dry analytical reagent for detecting γ-glutamyl transpeptidase according to claim 2, wherein: The surfactant is preferably a nonionic surfactant having a chain structure consisting of 8 to 15 oxyethylene or oxypropylene groups linked to each other.

4. The dry analytical reagent for detecting γ-glutamyl transpeptidase according to claim 3, wherein: The buffer solution has a pH value in the range of 7.0 to 9.0, and contains tris(hydroxymethyl)aminomethane (tris), phosphate, borate, 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, sodium salt or potassium salt of 1,4-piperazine-diethanesulfonic acid (PIPES), and one of the following: an acid, a base, or a salt combined with any of the above compounds.

5. The dry analytical reagent for detecting γ-glutamyl transpeptidase according to claim 4, wherein: The stabilizer is one or more polysaccharides or disaccharides; 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.

6. The dry analytical reagent for detecting γ-glutamyl transpeptidase according to claim 5, characterized in that: The upper support (1), the lower support (5) and the intermediate support (6) are all transparent plastic substrates with a light transmittance of more than 80% under a wavelength of 200nm-900nm, including one of polyethylene terephthalate, polycarbonate, polypropylene and polyethylene, and have a thickness of 50-300μm.

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