Preparation method of electrochemical sensor and streptomycin detection method

Abstract

The invention relates to a preparation method of an electrochemical sensor, which comprises the following steps: mixing bovine serum albumin, glutaraldehyde, cysteine and porous graphene to form a precursor solution, dripping the precursor solution on the surface of a working electrode containing gold, and drying to form an anti-fouling interface. Cysteine not only enables an anti-fouling interface to be stably fixed on a working electrode, but also can form a firm structure with bovine serum albumin under the reaction of glutaraldehyde to fix porous graphene, and the porous graphene can provide a larger surface area and can load more bioactive molecules, so that the bioactivity of the electrode is improved. The anti-fouling interface can ensure the activity of bioactive molecules and prevent other substances from being adsorbed on the surface of the electrode, so that the sensitivity of the electrochemical sensor can be improved. The invention also provides a streptomycin detection method.

Description

Technical Field

[0001] The present invention relates to the technical field of electrochemical detection, and in particular to a method for preparing an electrochemical sensor and a method for detecting streptomycin. Background Art

[0002] As an important analytical tool, electrochemical sensors have received extensive attention in the fields of biomedicine, environmental monitoring, and food safety in recent years.

[0003] However, when electrochemical sensors are used for detection, the activity of the fixed bioactive substances is low and the quantity is limited, resulting in low sensitivity of the electrochemical sensors.

[0004] It should be noted that the information disclosed in the above background technology section is only used to enhance the understanding of the background of the present invention, and therefore may include information that does not constitute prior art known to ordinary technicians in the field. Summary of the invention

[0005] The purpose of the present invention is to overcome the problem that the activity and quantity of fixed biologically active substances are low, resulting in low sensitivity of electrochemical biosensors, and to provide a method for preparing an electrochemical sensor and a method for detecting streptomycin.

[0006] According to one aspect of the present invention, a method for preparing an electrochemical sensor is provided, the method comprising:

[0007] mixing bovine serum albumin, glutaraldehyde, cysteine ​​and porous graphene to form a precursor solution;

[0008] The precursor solution is dropped onto the surface of the working electrode containing gold and dried to form an antifouling interface;

[0009] Immobilizing streptomycin antibody on the working electrode with antifouling interface;

[0010] Bovine serum albumin solution was added dropwise to the surface of the working electrode for incubation to block other active sites of the antifouling interface.

[0011] In one embodiment of the present invention, the method further comprises preparing porous graphene, and the preparing porous graphene comprises:

[0012] adding graphite oxide into a cobalt acetate tetrahydrate solution for ultrasonic dispersion, and rapidly freezing the uniformly dispersed mixed solution of graphite oxide and cobalt acetate tetrahydrate;

[0013] The freeze-dried solid mixture is subjected to high temperature heat treatment to obtain graphene-Co;

[0014] The graphene-Co is treated with a mixture of concentrated hydrochloric acid and hydrogen peroxide to form porous graphene;

[0015] The porous graphene was washed with ultrapure water until it was neutral and then dried in vacuum.

[0016] In one embodiment of the present invention, bovine serum albumin, glutaraldehyde, cysteine ​​and porous graphene are mixed to form a precursor solution, comprising:

[0017] Preparing a 0.01-0.1%wt graphene solution;

[0018] Adding 5-15 mg of cysteine ​​to the graphene solution to form a first mixed solution of 0.1-1% wt;

[0019] A 0.1-1% wt glutaraldehyde solution is fully mixed with the first mixed solution to form a precursor solution.

[0020] In one embodiment of the present invention, preparing a 0.01-0.1%wt graphene solution comprises:

[0021] Add 10-25 mg of bovine serum albumin into deionized water to prepare a 0.5-5% wt BSA solution;

[0022] An appropriate amount of porous graphene is added to the BSA solution, and a cell disruptor is used for ultrasonication for 15 to 30 minutes to obtain a 0.01 to 0.1% wt graphene solution.

[0023] In one embodiment of the present invention, immobilizing streptomycin antibody on a working electrode having an anti-fouling interface comprises:

[0024] Add 5-10ul of a mixed solution of 200-400mmol / L N-ethyl-N(3-dimethylaminopropyl)carbodiimide and 200-400mmol / L N-hydroxysuccinimide to the working electrode and incubate at room temperature in the dark for 0.5-4h;

[0025] Add 5 to 10 ul of 100 ug to 1000 ug / ml streptomycin antibody to the surface of the working electrode and incubate at room temperature for 1 to 4 hours.

[0026] In one embodiment of the present invention, the precursor solution is dropped onto the surface of a working electrode containing gold and dried, comprising:

[0027] Drop 5-10ul of the precursor solution onto the surface of the working electrode containing gold and leave it at room temperature for 12-24h.

[0028] In one embodiment of the present invention, a bovine serum albumin solution is added dropwise on the surface of the working electrode for incubation, comprising: adding a 0.5-3% wt BSA solution dropwise on the surface of the working electrode, and incubating at room temperature for 0.5-2 hours.

[0029] In one embodiment of the present invention, the method further comprises: modifying the working electrode with gold.

[0030] According to another aspect of the present invention, a method for detecting streptomycin is provided, using the electrochemical sensor according to any one of the aspects of the present invention, the method comprising:

[0031] Mixing the test solution containing streptomycin and the quantitative streptomycin-BSA coupled antigen to form a second mixed solution;

[0032] Dropping the second mixed solution on the antifouling interface of the working electrode, using streptomycin and the quantitative streptomycin-BSA coupled antigen in the second mixed solution to simultaneously compete with the antibody molecules fixed on the antifouling interface of the working electrode;

[0033] The measuring current value of the working electrode was measured by differential pulse voltammetry;

[0034] The streptomycin content of the test solution is determined according to the measured current value and the standard current-concentration curve of the electrochemical immunosensor.

[0035] In one embodiment of the present invention, the method further comprises drawing a standard current-concentration curve, and the step of drawing the standard current-concentration curve comprises:

[0036] Prepare at least two standard solutions of streptomycin antigen standard concentrations;

[0037] Differential pulse voltammetry was used to measure the standard current value of the working electrode at each standard concentration of streptomycin antigen;

[0038] Draw the antigen standard voltage-current curve of different standard concentrations of streptomycin.

[0039] The preparation method of the electrochemical sensor of the present invention comprises the following steps: mixing bovine serum albumin, glutaraldehyde, cysteine ​​and porous graphene to form a precursor solution, and dripping the precursor solution on the surface of a working electrode containing gold and drying the mixture to form an antifouling interface. Cysteine ​​can not only stably fix the antifouling interface on the working electrode, but also can react with bovine serum albumin to form a solid structure to fix the porous graphene under the reaction of glutaraldehyde. The porous graphene can provide a large surface area and can load more bioactive molecules. The antifouling interface can ensure the activity of the bioactive molecules and prevent other substances from being adsorbed on the surface of the electrode, thereby improving the sensitivity of the electrochemical sensor.

[0040] It is to be understood that both the foregoing general description and the following detailed description are exemplary and explanatory only and are not restrictive of the invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0041] The accompanying drawings herein are incorporated into and constitute a part of the specification, illustrate embodiments consistent with the present invention, and together with the specification are used to explain the principles of the present invention. Obviously, the accompanying drawings described below are only some embodiments of the present invention, and for those of ordinary skill in the art, other accompanying drawings can be obtained based on these accompanying drawings without creative work.

[0042] Figure 1 A schematic diagram of the preparation process of an electrochemical sensor is provided for an embodiment of the present invention.

[0043] Figure 2 A scanning electron microscope image of porous graphene provided in an embodiment of the present invention.

[0044] Figure 3 A schematic diagram of an anti-fouling performance test curve of an anti-fouling interface provided in an embodiment of the present invention.

[0045] Figure 4 A schematic diagram of the preparation process of the electrochemical sensor provided in an embodiment of the present invention.

[0046] Figure 5 Schematic diagram of the standard current-voltage curve of the electrochemical immunosensor in response to different standard concentrations of streptomycin. DETAILED DESCRIPTION

[0047] Example embodiments will now be described more fully with reference to the accompanying drawings. However, the example embodiments can be implemented in a variety of forms and should not be construed as limited to the embodiments set forth herein; rather, these embodiments are provided so that the present invention will be comprehensive and complete and fully convey the concepts of the example embodiments to those skilled in the art. The same reference numerals in the figures represent the same or similar structures, and thus their detailed description will be omitted. In addition, the drawings are only schematic illustrations of the present invention and are not necessarily drawn to scale.

[0048] Although relative terms such as "upper" and "lower" are used in this specification to describe the relative relationship of one component of the diagram to another component, these terms are used in this specification only for convenience, such as according to the direction of the examples in the drawings. It is understood that if the device of the diagram is turned upside down, the component described as "upper" will become the component "lower". When a structure is "on" other structures, it may mean that the structure is formed integrally on the other structure, or that the structure is "directly" disposed on the other structure, or that the structure is "indirectly" disposed on the other structure through another structure.

[0049] The terms "a", "an", "the", "said" and "at least one" are used to indicate the presence of one or more elements / components / etc.; the terms "including" and "having" are used to express an open-ended inclusive meaning and mean that additional elements / components / etc. may exist in addition to the listed elements / components / etc.; the terms "first", "second" and "third" etc. are used merely as labels and are not intended to limit the quantity of their objects.

[0050] As an important analytical tool, electrochemical sensors have received extensive attention in recent years in the fields of biomedicine, environmental monitoring, and food safety. Their main advantages are high sensitivity and rapid response, which can detect low concentrations of biomolecules and provide real-time data. In addition, electrochemical sensors are usually portable and have simple operation procedures, making on-site analysis more efficient and suitable for use under conditions with limited resources. However, electrochemical sensors also have some disadvantages, such as limitations in materials and methods, which make the activity of fixed bioactive substances low and limited in quantity, resulting in low sensitivity of electrochemical sensors.

[0051] Based on this, an embodiment of the present invention provides a method for preparing an electrochemical sensor. Figure 1 As shown, the method may include:

[0052] Step S10, mixing bovine serum albumin, glutaraldehyde, cysteine ​​and porous graphene to form a precursor solution;

[0053] Step S20, dropping the precursor solution on the surface of the working electrode containing gold and drying it to form an anti-fouling interface;

[0054] Step S30, immobilizing streptomycin antibody on the working electrode having an anti-fouling interface;

[0055] Step S40, adding bovine serum albumin solution to the surface of the working electrode for incubation to block other active sites of the anti-fouling interface.

[0056] The method mixes bovine serum albumin, glutaraldehyde, cysteine ​​and porous graphene to form a precursor solution, and then drops the precursor solution on the surface of a working electrode containing gold and dries it to form an antifouling interface. Cysteine ​​can not only stably fix the antifouling interface on the working electrode, but also form a strong structure with bovine serum albumin under the reaction of glutaraldehyde to fix the porous graphene. The porous graphene can provide a large surface area and can load more bioactive molecules. The antifouling interface can ensure the activity of the bioactive molecules and prevent other substances from being adsorbed on the surface of the electrode, thereby improving the sensitivity of the electrochemical sensor.

[0057] The preparation method of the electrochemical sensor according to the embodiment of the present invention is described in detail below with reference to specific examples.

[0058] Before step S10, the method may further include preparing porous graphene, and the preparation of porous graphene may include:

[0059] 60 mg of graphite oxide (GO) was weighed and dispersed in ultrapure water, and then slowly added into a rapidly stirred cobalt acetate tetrahydrate solution. The mass ratio of graphite oxide to metallic cobalt was 4:1. Ultrasonication was performed for 20 minutes. The uniformly dispersed mixed solution of graphite oxide and cobalt acetate tetrahydrate was quickly frozen using liquid nitrogen and then freeze-dried for 48 hours.

[0060] The freeze-dried solid mixture is subjected to high-temperature heat treatment under an argon protective atmosphere to obtain an intermediate product, graphene-Co. It should be noted that the high-temperature heat treatment process must be kept at 850° C. for at least 1.5 hours.

[0061] The intermediate product graphene-Co is treated with a mixture of concentrated hydrochloric acid and hydrogen peroxide to remove Co and form porous graphene. The porous graphene is washed with ultrapure water until it is neutral, filtered and vacuum dried. It should be noted that the vacuum drying process must be kept at 70°C for at least 12 hours to form Figure 2 The porous graphene shown.

[0062] In step S10, bovine serum albumin, glutaraldehyde, cysteine ​​and porous graphene are mixed to form a precursor solution, which may include:

[0063] 10-25 mg of bovine serum albumin is added into deionized water to prepare a 0.5-5% wt BSA solution.

[0064] An appropriate amount of porous graphene is added to the BSA solution, and a cell disruptor is used for ultrasonication for 15 to 30 minutes to obtain a 0.01 to 0.1% wt graphene solution.

[0065] 5-15 mg of cysteine ​​is added to the graphene solution to form a first mixed solution of 0.1-1% wt.

[0066] A 0.1-1% wt glutaraldehyde solution is fully mixed with the first mixed solution to form a precursor solution.

[0067] Before step S20, the method may further include: preparing a three-electrode system by screen printing, including a counter electrode, a working electrode and a reference electrode, and then modifying the working electrode with gold.

[0068] The three-electrode system prepared by screen printing may include:

[0069] A polyethylene terephthalate (PET) film is prepared, and a plasma cleaning machine is used to perform surface treatment on the polyethylene terephthalate film.

[0070] Prepare carbon paste and silver chloride paste, prepare a counter electrode, a working electrode and a wire with carbon paste on a polyethylene terephthalate film by screen printing, and prepare a reference electrode with silver chloride, and dry them in an oven at 100-120° C. for 10-20 min.

[0071] The prepared three-electrode system (including a counter electrode, a working electrode and a reference electrode) was immersed in a 0.1-1 mol / L NaOH solution for 30 min and then placed in a dust-free environment for standby use.

[0072] Gold modified working electrodes can include:

[0073] A 0.5 wt% aqueous solution of chloroauric acid was prepared.

[0074] 100 μL of chloroauric acid aqueous solution was dropped on the three-electrode system, and electrochemical deposition was performed by constant voltage electrochemical reduction of chloroauric acid aqueous solution to modify gold on the working electrode. It should be noted that the voltage applied for electrochemical deposition ranged from -0.2 to 0.6 V, the mid-potential was -0.5 V, and the electrochemical deposition time was 120 s.

[0075] The surface of the three-electrode system was cleaned three times with ultrapure water.

[0076] In step S20, the precursor solution is dripped onto the surface of the working electrode containing gold and dried to form an anti-fouling interface, including: taking 10ul of the precursor solution and dripping it onto the working electrode, leaving it at room temperature for 12 to 24 hours to form an anti-fouling interface.

[0077] Between step S20 and step S30, the antifouling performance of the antifouling interface may be tested, including:

[0078] Prepare a control group, drop 0.1M PBS solution on the anti-fouling interface and incubate for 1 hour, then rinse with pure water and blow dry with nitrogen; then drop 10ul of streptomycin-BSA coupled antigen, 10ul of melamine-BSA coupled antigen, and 10ul of aflatoxin-BSA coupled antigen on the working electrode with the anti-fouling interface, incubate at room temperature for 1 hour, then rinse with pure water and blow dry with nitrogen; add 5mmol / L [Fe(CN)6]4- / 3- solution as the electrolyte solution, and detect it by differential pulse voltammetry.

[0079] Different coupled antigen molecules were used for incubation. It was found that the voltage-current curve L1 of streptomycin-BSA, the voltage-current curve L2 of melamine-BSA and the voltage-current curve L3 of aflatoxin-BSA were very different from the voltage-current curve L4 of the working electrode of the blank group (without any coupled antigen molecules added). It can be seen that the anti-fouling effect of the anti-fouling interface is relatively good. Figure 3 shown.

[0080] In step S30, immobilizing the streptomycin antibody on the working electrode having the anti-fouling interface may include:

[0081] Add 5-10ul of a mixed solution of 200-400mmol / L N-ethyl-N(3-dimethylaminopropyl)carbodiimide and 200-400mmol / L N-hydroxysuccinimide on the working electrode, incubate at room temperature in the dark for 0.5-4h to activate the carboxyl groups on the surface of the working electrode, wash the working electrode after the first incubation with phosphate buffered saline solution, and slowly blow dry the surface of the working electrode with nitrogen gas.

[0082] Add 5-10ul of 100ug-1000ug / ml streptomycin antibody to the surface of the working electrode and incubate at room temperature for 1-4 hours to allow the amino group in the streptomycin antibody to react with the activated carboxyl group, so that the streptomycin antibody is fixed on the working electrode containing the antifouling interface. After the second incubation, wash the working electrode with phosphate buffered saline solution, and slowly blow dry the surface of the working electrode with nitrogen gas.

[0083] In step S40, a bovine serum albumin solution is added to the surface of the working electrode for incubation to block other active sites of the antifouling interface, including: adding 0.5-3% wt BSA solution to the surface of the working electrode and incubating at room temperature for 0.5-2 hours.

[0084] The present invention provides a method for detecting streptomycin. Figure 4 As shown, the method may include:

[0085] Step S100, mixing a test solution containing streptomycin and a quantitative streptomycin-BSA coupled antigen to form a second mixed solution;

[0086] Step S200, dropping the second mixed solution on the anti-fouling interface of the working electrode, using the streptomycin and the quantitative streptomycin-BSA coupled antigen in the second mixed solution to simultaneously compete with the antibody molecules fixed on the anti-fouling interface of the working electrode;

[0087] Step S300, measuring the current value of the working electrode by differential pulse voltammetry;

[0088] Step S400, determining the streptomycin content of the test solution according to the measured current value and the standard differential pulse voltammetry curve of the electrochemical immunosensor.

[0089] This method mixes the streptomycin antigen to be tested with a quantitative streptomycin-BSA coupled antigen to compete with the antibody molecules on the working electrode. During the detection process, the differential pulse voltammetry method is used to measure the measured current value of the working electrode, and the streptomycin antigen detection concentration of the solution to be tested is determined based on the measured current value and the standard current-concentration curve of the electrochemical immunosensor. This method detects the streptomycin antigen in the solution to be tested by a competitive method, and has high sensitivity and high specificity. This detection method is simple to operate, low cost, high sensitivity, and easier to promote. It can be widely used in scenarios such as environmental testing, food testing, and disease testing.

[0090] The method further comprises drawing a standard current-voltage curve, wherein the drawing step of the standard current-voltage curve comprises: preparing at least two standard solutions of streptomycin antigen standard concentrations; measuring the standard current value of the working electrode at each streptomycin antigen standard concentration by differential pulse voltammetry; drawing a standard current-voltage curve according to the streptomycin antigen standard concentration and the standard current value. Figure 5 The standard current-voltage curve is shown.

[0091] The specific process of drawing the standard current-concentration curve is as follows: use phosphate buffered saline to prepare standard solutions of different streptomycin standard concentrations of 0 ng / mL, 50 ng / mL, 100 ng / mL, 200 ng / mL, 300 ng / mL, and 500 ng / mL, and set up a blank control group with phosphate buffered saline.

[0092] 15 μL of 200ug / ml streptomycin-BSA coupled antigen and 15 μL of streptomycin solutions of different concentrations were mixed evenly.

[0093] Then, 10 μL of mixed solutions corresponding to different streptomycin standard concentrations were dropped onto the working electrode surface of the electrochemical sensor, so that the immobilized streptomycin antibody competed with the streptomycin antigen and the streptomycin-BSA coupled antigen in the test solution.

[0094] Using 5mmol / L [Fe(CN)6]4- / 3- solution as the electrolyte solution, differential pulse voltammetry was used to detect the gold-modified working electrode, and the following results were obtained: Figure 5The schematic diagram of the voltage-current curve of the electrochemical sensor for different concentrations of the analyte is shown. Wherein M1 is the voltage-current curve of the standard solution with a standard concentration of 50 ng / mL streptomycin, M2 is the voltage-current curve of the standard solution with a standard concentration of 100 ng / mL streptomycin, M3 is the voltage-current curve of the standard solution with a standard concentration of 200 ng / mL streptomycin, M4 is the voltage-current curve of the standard solution with a standard concentration of 300 ng / mL streptomycin, M5 is the voltage-current curve of the standard solution with a standard concentration of 500 ng / mL streptomycin, and M6 is the voltage-current curve of the standard solution with a standard concentration of 0 ng / mL streptomycin.

[0095] According to the current value corresponding to the set voltage, it can correspond to the voltage-current curve of a standard solution with a certain streptomycin standard concentration, thereby determining the streptomycin content of the solution to be tested.

[0096] Those skilled in the art will readily appreciate other embodiments of the present invention after considering the specification and practicing the disclosure of the invention herein. This application is intended to cover any variations, uses or adaptations of the present invention, which follow the general principles of the present invention and include common knowledge or customary techniques in the art that are not disclosed by the present invention. The specification and examples are intended to be exemplary only, and the true scope and spirit of the present invention are indicated by the appended claims.

Claims

1. A method for preparing an electrochemical sensor, characterized in that: The method comprises: mixing bovine serum albumin, glutaraldehyde, cysteine ​​and porous graphene to form a precursor solution; Dropping the precursor solution on the surface of a working electrode containing gold and drying it to form an antifouling interface; immobilizing streptomycin antibody on the working electrode having an antifouling interface; A bovine serum albumin solution is dripped onto the surface of the working electrode for incubation to block other active sites of the antifouling interface.

2. The method for preparing an electrochemical sensor according to claim 1, characterized in that: The method further comprises preparing porous graphene, and the preparation of porous graphene comprises: adding graphite oxide into a cobalt acetate tetrahydrate solution for ultrasonic dispersion, and rapidly freezing the uniformly dispersed mixed solution of graphite oxide and cobalt acetate tetrahydrate; The freeze-dried solid mixture is subjected to high temperature heat treatment to obtain graphene-Co; The graphene-Co is treated with a mixture of concentrated hydrochloric acid and hydrogen peroxide to form porous graphene; The porous graphene is washed with ultrapure water until it becomes neutral, and then vacuum dried.

3. The method for preparing an electrochemical sensor according to claim 1, characterized in that: Bovine serum albumin, glutaraldehyde, cysteine ​​and porous graphene are mixed to form a precursor solution, including: Preparing a 0.01-0.1%wt graphene solution; Adding 5-15 mg of cysteine ​​to the graphene solution to form a first mixed solution of 0.1-1% wt; A 0.1-1% wt glutaraldehyde solution is fully mixed with the first mixed solution to form a precursor solution.

4. The method for preparing an electrochemical sensor according to claim 1, characterized in that: A 0.01-0.1%wt graphene solution is prepared, comprising: Add 10-25 mg of bovine serum albumin into deionized water to prepare a 0.5-5% wt BSA solution; An appropriate amount of porous graphene is added to the BSA solution, and a cell disruptor is used for ultrasonication for 15 to 30 minutes to obtain a 0.01 to 0.1% wt graphene solution.

5. The method for preparing an electrochemical sensor according to claim 4, characterized in that: Immobilizing streptomycin antibody on the working electrode having an antifouling interface comprises: Add 5-10 ul of a mixed solution of 200-400 mmol / L N-ethyl-N(3-dimethylaminopropyl)carbodiimide and 200-400 mmol / L N-hydroxysuccinimide to the working electrode, and incubate at room temperature in the dark for 0.5-4 h; 5 to 10 ul of 100 ug to 1000 ug / ml streptomycin antibody is added dropwise to the surface of the working electrode and incubated at room temperature for 1 to 4 hours.

6. The method for preparing an electrochemical sensor according to claim 1, characterized in that: Dropping the precursor solution on the surface of a working electrode containing gold and drying it, comprising: 5 to 10 ul of the precursor solution is dropped onto the surface of the working electrode containing gold and left at room temperature for 12 to 24 hours.

7. The method for preparing an electrochemical sensor according to claim 6, characterized in that: Adding bovine serum albumin solution dropwise on the surface of the working electrode for incubation includes: adding 0.5-3%wt BSA solution dropwise on the surface of the working electrode and incubating for 0.5-2h at room temperature.

8. The method for preparing an electrochemical sensor according to claim 6, characterized in that: The method further comprises: modifying the working electrode with gold.

9. A method for detecting streptomycin, using the electrochemical sensor according to any one of claims 1 to 8, characterized in that: The method comprises: Mixing the test solution containing streptomycin and the quantitative streptomycin-BSA coupled antigen to form a second mixed solution; Dropping the second mixed solution on the antifouling interface of the working electrode, using the streptomycin and the quantitative streptomycin-BSA coupled antigen in the second mixed solution to simultaneously compete with the antibody molecules fixed on the antifouling interface of the working electrode; The differential pulse voltammetry method is used to measure the current value of the working electrode; The streptomycin content of the test solution is determined according to the measured current value and the standard current-concentration curve of the electrochemical immunosensor.

10. The method for detecting streptomycin according to claim 9, characterized in that: The method further comprises drawing the standard current-concentration curve, and the step of drawing the standard current-concentration curve comprises: Prepare at least two standard solutions of streptomycin antigen standard concentrations; Differential pulse voltammetry was used to measure the standard current value of the working electrode at each standard concentration of streptomycin antigen; Draw the antigen standard voltage-current curve of different standard concentrations of streptomycin.

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