Electrochemical immunosensor for PGⅠ protein detection and its preparation method and application

Abstract

The present invention relates to the technical field of electrochemical immunosensors, and in particular to an electrochemical immunosensor for detecting PGⅠ protein and a preparation method and application thereof, comprising electrodepositing aniline on the working electrode surface of a screen-printed electrode to obtain electrodeposited polyaniline; preparing MoS 2 and Cu 3 Pt;MoS 2 With Cu 3 Pt was then mixed by oscillation and washed by centrifugation and then dispersed in 3 mL of ultrapure water to obtain MoS 2 @Cu 3 PtNPs mixed solution; MoS 2 @Cu 3 The PtNPs mixed solution is dripped onto the surface of the modified electrode deposited with aniline, and then dried at a constant temperature in a constant temperature incubator; the electrode is rinsed with ultrapure water; PG I antibody is dripped onto the modified electrode until the PG I antibody is completely fixed; 1% bovine serum albumin is dripped onto the electrode surface and incubated for 30 min to obtain an electrochemical immunosensor. The electrochemical immunosensor detects PG in serum by electrochemical method without the aid of other large instruments, thus solving the problem of high detection cost of existing methods for detecting PG.

Description

Technical Field

[0001] The present invention relates to the technical field of electrochemical immunosensors, and in particular to an electrochemical immunosensor for detecting PGⅠ protein and a preparation method and application thereof. Background Art

[0002] Gastric cancer is a common malignant tumor of the digestive tract. Gastroscopy and pathological biopsy are still the only methods to diagnose gastric cancer. However, due to their high cost and invasiveness, they are not widely accepted by the general public and are difficult to apply to large-scale censuses. Therefore, it is a more ideal method to first screen out the high-risk population for gastric cancer through non-invasive examinations and then conduct detailed examinations under gastroscopy.

[0003] Serum testing has the advantages of simple operation, high population acceptance and repeatability, and is more suitable for large-scale human screening. Pepsinogen (PG), as an inactive precursor of pepsin, has become an important marker for serological diagnosis of gastric cancer. Because the stomach is the only source of PG, and it is not affected by short-term diet or other external conditions, and enters the bloodstream through the gastric mucosa. Therefore, the PG level in the serum of each individual is relatively stable and can accurately reflect the state of the gastric mucosa.

[0004] Although several methods are available for detecting PG, such as radioimmunoassays (RIAs), enzyme-linked immunosorbent assays (ELISA), enzyme immunoassays (EIAs), and time-resolved fluorescence immunoassays (TRFIAs), these methods are capable of detecting PG but require large instruments for testing, making the testing costly. Summary of the invention

[0005] The purpose of the present invention is to provide an electrochemical immunosensor for detecting PGⅠ protein and a preparation method and application thereof, aiming to solve the problem of high detection cost of existing methods for detecting PG.

[0006] To achieve the above objectives, in a first aspect, the present invention provides a method for preparing an electrochemical immunosensor for detecting PGⅠ protein, comprising the following steps:

[0007] Electrodepositing aniline on the working electrode surface of the screen-printed electrode to obtain electrodeposited polyaniline;

[0008] Preparation of MoS2 and Cu3Pt;

[0009] The MoS2 and the Cu3Pt are sequentially subjected to oscillation mixing and centrifugal washing and then dispersed in 3 mL of ultrapure water to obtain a MoS2@Cu3PtNPs mixed solution;

[0010] The MoS2@Cu3PtNPs mixed solution is added dropwise onto the surface of the modified electrode on which the polyaniline is electrodeposited, and dried at a constant temperature in a constant temperature incubator;

[0011] Rinse the electrode with ultrapure water;

[0012] Taking PG I antibody and dropping it onto the washed electrode until the PG I antibody is completely fixed;

[0013] 1% bovine serum albumin was dropped onto the electrode surface and incubated for 30 minutes to obtain an electrochemical immunosensor.

[0014] Wherein, the step of electrodepositing aniline on the working electrode surface of the screen-printed electrode to obtain electrodeposited polyaniline comprises:

[0015] Dissolve 0.15 M aniline in ultrapure water, then add 0.5 M H2SO4 and mix well to obtain an aniline solution;

[0016] 50 μL of the aniline solution was dropped onto the working electrode surface of the screen-printed electrode, and the electrode surface was cyclically scanned 15 times in the range of -0.2V to 1.1V at a rate of 50 mV / s to obtain electrodeposited polyaniline.

[0017] Wherein, the preparation of MoS2 comprises:

[0018] Take 1.24g of ammonium heptamolybdate (NH4)6Mo7O 24 4H2O was dissolved in 15mL ultrapure water, followed by the addition of 1.67g aniline. After complete dissolution, 1M HCl was added dropwise under magnetic stirring at room temperature until a white precipitate appeared. The mixture was placed in a constant temperature incubator at 50°C for 2h to obtain a solution product.

[0019] The solution product is filtered, washed with ethanol and dried at 50° C. to obtain MoO3;

[0020] 0.1 g of MoO3 was dissolved in 20 mL of ultrapure water and ultrasonicated for 5 min until the MoO3 was completely dissolved to obtain a first solution;

[0021] Add 0.28 g of L-cysteine ​​to the first solution during stirring to obtain a second solution;

[0022] The obtained second dissolved liquid was transferred into a high-pressure reactor, reacted at 200°C for 14 hours, cooled to room temperature in the furnace, taken out, centrifuged, washed, dried at 50°C and ground to obtain MoS2.

[0023] Wherein, the preparation of Cu3Pt comprises:

[0024] At 60°C, add 160 mg of CTAC to 20 mL of oleylamine solution and stir to obtain a homogeneous solution;

[0025] 16 mg of Pt(acac)2, 7 mg of CuCl2·H2O and 61 mg of Tris solution were sequentially added to the homogeneous solution and stirred to obtain a polymerization solution;

[0026] The polymerization solution was ultrasonicated for 30 minutes and then transferred into an autoclave, heated at 180° C. for 10 hours, cooled to room temperature in the oven, taken out, washed by centrifugation with ethanol and cyclohexane, and dried at 60° C. to obtain Cu3PtNPs.

[0027] The method of sequentially oscillating and centrifugally washing the MoS2 and the Cu3Pt and then dispersing them in 3 mL of ultrapure water to obtain a MoS2@Cu3PtNPs mixed solution comprises:

[0028] Mix 1 mL of the MoS2 with 2.5 mL of the Cu3Pt to obtain a mixed solution;

[0029] The mixed solution was shaken at a low speed for 12 h in the dark, then centrifuged and washed and dispersed in 3 mL of ultrapure water to obtain a MoS2@Cu3PtNPs mixed solution.

[0030] In a second aspect, the present invention provides an electrochemical immunosensor for detecting PG I protein, comprising a screen-printed electrode, MoS2, Cu3Pt, PG I antibody and bovine serum albumin.

[0031] In a third aspect, the present invention provides an application of an electrochemical immunosensor for detecting PGⅠ protein, which is applied to PGⅠ detection.

[0032] The present invention discloses an electrochemical immunosensor for detecting PGⅠ protein, and a preparation method and application thereof. The method comprises the following steps: electrochemically depositing aniline on the working electrode surface of a screen-printed electrode to obtain electrochemically deposited polyaniline; preparing MoS2 and Cu3Pt; sequentially performing oscillation mixing and centrifugal washing on the MoS2 and the Cu3Pt and then dispersing them in 3 mL of ultrapure water to obtain a MoS2@Cu3PtNPs mixed solution; dripping the MoS2@Cu3PtNPs mixed solution onto the surface of the modified electrode after the electrochemically deposited polyaniline, and drying the solution at a constant temperature in a constant temperature incubator; rinsing the electrode with ultrapure water; dripping PG I antibody onto the rinsed electrode until the PG I antibody is completely fixed; dripping 1% bovine serum albumin onto the electrode surface and incubating for 30 minutes to obtain an electrochemical immunosensor. The electrochemical immunosensor obtained by the present invention detects PG in serum by an electrochemical method, has lower cost and faster detection speed, and does not require the aid of other large instruments, thereby solving the problem of high detection cost of the existing method for detecting PG. BRIEF DESCRIPTION OF THE DRAWINGS

[0033] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0034] Figure 1 The present invention provides a flow chart of a method for preparing an electrochemical immunosensor for detecting PGⅠ protein.

[0035] Figure 2 M[Fe(CN)6] 3- / 4- Schematic diagram of the step-by-step fabrication process of the sensor using CV.

[0036] Figure 3 M[Fe(CN)6] 3- / 4- Schematic diagram of sensor characterization using EIS.

[0037] Figure 4 Schematic diagram of the structure of MoS2@Cu3Pt characterized by energy dispersive X-ray spectroscopy.

[0038] Figure 5 is a schematic diagram of the XPS spectrum when there is no modification material on the surface of the working electrode.

[0039] Figure 6 is a schematic diagram of the DPV response of the immunosensor after incubation with different concentrations of PGⅠ.

[0040] Figure 7 This is a schematic diagram of the linear relationship between the current response of PGⅠ and the logarithm of the concentration. DETAILED DESCRIPTION

[0041] Embodiments of the present invention are described in detail below, examples of which are shown in the accompanying drawings, wherein the same or similar reference numerals throughout represent the same or similar elements or elements having the same or similar functions. The embodiments described below with reference to the accompanying drawings are exemplary and are intended to be used to explain the present invention, and should not be construed as limiting the present invention.

[0042] See also Figure 1 In a first aspect, the present invention provides a method for preparing an electrochemical immunosensor for detecting PGⅠ protein, comprising the following steps:

[0043] S1 electrodeposit aniline on the working electrode surface of the screen-printed electrode to obtain electrodeposited polyaniline;

[0044] Specifically include:

[0045] S11 0.15 M aniline was dissolved in ultrapure water, and then 0.5 M H2SO4 was added and mixed to obtain an aniline solution;

[0046] S12: 50 μL of the aniline solution is dropped onto the working electrode surface of the screen-printed electrode, and the electrode surface is cyclically scanned 15 times in the range of -0.2 V to 1.1 V at a rate of 50 mV / s to obtain electrodeposited polyaniline.

[0047] S2 to prepare MoS2 and Cu3Pt;

[0048] The preparation of MoS2 comprises:

[0049] S201 takes 1.24g of ammonium heptamolybdate (NH4)6Mo7O 24 4H2O was dissolved in 15mL ultrapure water, followed by the addition of 1.67g aniline. After complete dissolution, 1M HCl was added dropwise under magnetic stirring at room temperature until a white precipitate appeared. The mixture was placed in a constant temperature incubator at 50°C for 2h to obtain a solution product.

[0050] S202 sequentially filters the solution product, washes it with ethanol and dries it at 50° C. to obtain MoO3;

[0051] S203 0.1 g of MoO3 was dissolved in 20 mL of ultrapure water and ultrasonicated for 5 min until the MoO3 was completely dissolved to obtain a first solution;

[0052] S204 adds 0.28 g of L-cysteine ​​to the first dissolved solution during stirring to obtain a second dissolved solution;

[0053] S205 The obtained second dissolved liquid is transferred into a high-pressure reactor, reacted at 200°C for 14 hours, cooled to room temperature with the furnace, taken out, centrifuged, washed, dried at 50°C and ground in sequence to obtain MoS2.

[0054] The preparation of Cu3Pt comprises:

[0055] S211: At 60 °C, 160 mg of CTAC was added to 20 mL of oleylamine solution and stirred to obtain a homogeneous solution;

[0056] S212 16 mg Pt(acac)2, 7 mg CuCl2·H2O and 61 mg Tris solution were added to the homogeneous solution in sequence and stirred to obtain a polymerization solution;

[0057] Specifically, 16 mg Pt(acac)2, 7 mg CuCl2·H2O and 61 mg Tris solution were added to the homogeneous solution in sequence and stirred until the color of the homogeneous solution changed from yellow to blue-green to obtain a polymerization solution.

[0058] S213 After ultrasonicating the polymerization solution for 30 minutes, the solution was transferred into an autoclave and heated at 180° C. for 10 hours. After cooling to room temperature in the oven, the solution was taken out and washed by centrifugation with ethanol and cyclohexane, and dried at 60° C. to obtain Cu3PtNPs.

[0059] S3: mixing the MoS2 and the Cu3Pt, and then sequentially performing oscillation mixing and centrifugal washing, and then dispersing them in 3 mL of ultrapure water to obtain a MoS2@Cu3PtNPs mixed solution;

[0060] Specifically include:

[0061] S31: 1 mL of the MoS2 is mixed with 2.5 mL of the Cu3Pt to obtain a mixed solution;

[0062] S32 The mixed solution is oscillated at a low speed for 12 h in the dark, then centrifuged and washed and dispersed in 3 mL of ultrapure water to obtain a MoS2@Cu3PtNPs mixed solution.

[0063] S4: adding the MoS2@Cu3PtNPs mixed solution dropwise onto the electrode surface via aniline electrodeposition, and drying at a constant temperature in a constant temperature incubator;

[0064] S5 rinses the electrode with ultrapure water;

[0065] Specifically, it was rinsed with ultrapure water to remove the unfixed composite material and dried for the next step.

[0066] S6: adding PG I antibody dropwise onto the washed electrode until the PG I antibody is completely fixed;

[0067] Specifically, 5.0 μL of anti-PG I (200 ng / mL) was added dropwise to the modified electrode and stored in a refrigerator at 4° C. for 12 h to completely immobilize the antibody.

[0068] S7: 1% bovine serum albumin is added dropwise onto the electrode surface and incubated for 30 minutes to obtain an electrochemical immunosensor.

[0069] Specifically, 10 μL of 1% bovine serum albumin (BSA) was added to the modified electrode surface and incubated for 30 min to avoid possible nonspecific adsorption. After each step, the prepared sensor was thoroughly cleaned with PBS (0.01 M) and dried.

[0070] Beneficial effects:

[0071] 1. The electrochemical method is used to detect PG in serum, which makes the examination process more humane compared with invasive detection methods such as gastroscopy;

[0072] 2. There are many methods for detecting PG in serum. The constructed label-free electrochemical sensor has lower cost, faster detection speed, and does not require the use of other large instruments;

[0073] 3. The constructed electrochemical sensor has a wider detection range and can sensitively detect 500pg mL -1 to 400ng mL -1 PG in range;

[0074] 4. The constructed electrochemical sensor is easy to store and has a long shelf life (experimental tests show that after being stored in a -4°C refrigerator for 30 days, the activity remains above 96%).

[0075] 5. The constructed sensor has good specificity and no false detection occurs when mixed with other interfering substances that often appear in serum.

[0076] In a second aspect, the present invention provides an electrochemical immunosensor for detecting PGⅠ protein, comprising a screen-printed electrode, MoS2, Cu3Pt, PG I antibody and bovine serum albumin.

[0077] Specifically, the present invention provides an electrochemical immunosensor for detecting PG I protein. Polyaniline is electro-deposited onto the surface of a screen-printed electrode by cyclic scanning to accelerate the electron transfer rate on the electrode surface, and because its surface has a certain degree of roughness, the amount of subsequent nanomaterial attachment can be increased. Cu3Pt NPS is fixed to the surface of MoS2 by physical adsorption, and the sensitivity and stability of the immunosensor are further improved by combining Cu-S and Pt-S with PG I antibody (anti-PG I).

[0078] See also Figures 2 to 7 In a third aspect, the present invention provides an application of an electrochemical immunosensor for detecting PGⅠ protein, which is applied to PGⅠ detection.

[0079] Specifically, first, aniline was electrodeposited onto the working electrode surface of the screen-printed electrode (SPE) by cyclic voltammetry to form a sensitive PANI layer to accelerate the electron transfer rate on the electrode surface, and because its surface has a certain roughness, it can increase the number of subsequent nanomaterial attachments. Subsequently, MoS2@Cu3PtNPs were added dropwise to the modified electrode surface to provide sufficient active sites for the subsequent fixation of antibodies, and because of its excellent electrochemical properties, it can further accelerate electron transfer. Subsequently, anti-PG I was fixed to the modified electrode surface through Cu-S and Pt-S bonds to achieve real-time detection of different concentrations of PG. The detection mechanism is based on monitoring the specific recognition between antibodies and antigens, and the immune proteins produced by the binding hinder the electron transfer rate on the working electrode surface, thereby causing changes in the peak current. In short, in this signal amplification strategy, the value of the electrochemical signal decreases when the antigen concentration increases. Therefore, the proposed immunosensor can effectively detect the target analyte (PG I).

[0080] In 5 mM [Fe(CN)6] 3- / 4- The step-by-step fabrication process of the immunosensor was characterized by CV and EIS in solution. Figure 2 As shown in Figure 2, the curve of the bare SPE (curve a) shows two characteristic redox peaks at 0.15 V and 0.29 V. This is because after the voltage is applied, [Fe(CN)6] 3- / 4- The electron pairs in the solution produce redox reactions. After the PANI modified electrode, the peak current increased significantly (curve b). When MoS2 NFs were deposited on the electrode surface, the peak current continued to increase (curve c). When the nanocomposite MoS2@Cu3Pt was added dropwise, the electrochemical response increased significantly (curve d), which is because Cu3Pt NPs have excellent electrochemical properties. However, when the modified electrode was incubated with anti-PG I (curve e), BSA (curve f) and PG I (curve e) in sequence, it can be observed that the peak current decreased in turn, because the immunoactive substances generated by the specific reaction greatly hindered the efficiency of electron transfer.

[0081] To further verify the stepwise modification process, the immunosensor was characterized using EIS ( Figure 3). The EIS image of the bare SPE shows a semicircle with a relatively large radius (curve a). When polyaniline was modified onto the electrode, the semicircle diameter decreased significantly (curve b), which is due to its good electrochemical activity and ability to improve electrochemical sensitivity. After the MoS2NFs were fixed, the semicircle diameter decreased significantly (curve c). When the MoS2@Cu3Pt nanocomposite modified the electrode surface, the impedance value was further reduced (curve b), indicating that the nanocomposite was conducive to the transmission of electrons. However, when anti-PG I was fixed on the modified electrode surface, the semicircle diameter increased significantly (curve e). When BSA blocked other unbound nonspecific sites on the electrode surface, the resistance increased further (curve f). When the modified electrode was incubated with PG I, the resistance increased further (curve g). All of the above phenomena can be explained as the bioactive substances produced by the specific antigen-antibody reaction hindering the efficiency of electron transfer. In addition, the obtained results were corroborated by the CV results, demonstrating the successful construction of the immunosensor.

[0082] The structure of MoS2@Cu3Pt was further characterized by energy dispersive X-ray spectroscopy (EDS), as shown above. Figure 4 As shown, Mo, S, Cu, and Pt elements are present in the EDS spectrum, which means that Cu3Pt NPs are successfully fixed to MoS2 NFs. In addition, elemental analysis using X-ray photoelectron spectroscopy (XPS) further confirmed the successful synthesis of MoS2@Cu3Pt nanocomposites. Figure 5 As shown, when there is no modification material on the working electrode surface, there are three main peaks in the XPS spectrum, namely 284.5eV (C 1s), 532.3eV (O 1s) and 399.3eV (N 1s) (curve a). In contrast, after electrodeposition of polyaniline nanocomposites (curve b), a new peak S 2p (226.7eV) was observed, indicating that polyaniline was successfully immobilized. After loading MoS2 NFs onto the modified electrode, an additional peak Mo 3d (171.2eV) was detected (curve c). Curve d shows two other peaks, Pt 4f (109.9eV) and Cu 2p (904.3eV), supporting that Cu3Pt NPs have been successfully modified.

[0083] In order to verify the analytical detection performance of the immunosensor, DPV was used to perform electrochemical detection of PGⅠ at different concentrations under the optimal experimental conditions. Figure 6 and Figure 7 As shown in Figure 2, the peak response decreased with the increase of PGⅠ concentration, and the detection range was 0.5 ng mL -1 Up to 400ng mL -1 The linear relationship between the logarithm of PGⅠ concentration and the current response is as above Figure 7As shown, the regression equation is I (μA) = -7.81logc PGⅠ (pg mL-1)+89.79, the correlation coefficient is 0.983, and the detection limit is 166.67pg mL-1 (S / N=3). The experimental results show that the prepared three-dimensional nanocomposite material has excellent electrochemical properties and a wide detection range.

[0084] Figure 6 DPV responses of the immunosensor after incubation with different concentrations of PGⅠ: 0.5, 0.75, 1, 2.5, 5, 10, 25, 50, 100, 200, 250, 300, and 400 ng mL -1 , detection solution PBS (pH=7.4).

[0085] Table 1. Comparison of detection results of clinical serum samples using the constructed sensor and chemiluminescence method

[0086]

[0087] To verify the reliability and accuracy of the constructed immunosensor in clinical practice, the concentration of PGⅠ in human serum samples from healthy individuals (sample 3) and patients (samples 1, 2, 4 and 5, Table 1) was measured. Chemiluminescence is often used to detect PG I in clinical practice and is therefore considered as a standard value here. The detection results of the constructed sensor were compared with those of the chemiluminescence method. The relative error between the two methods ranged from -15.07% to 5.76%. These data show that there is good consistency between the two analytical methods, indicating that the designed immunosensor has great potential clinical application value in the detection of PGⅠ.

[0088] The above disclosure is only an electrochemical immunosensor for PGⅠ protein detection and its preparation method and preferred application embodiment of the present invention. Of course, this cannot be used to limit the scope of rights of the present invention. Ordinary technicians in this field can understand that all or part of the processes of the above embodiments and equivalent changes made according to the claims of the present invention are still within the scope of the invention.

Claims

1. A method for preparing an electrochemical immunosensor for detecting PGⅠ protein, characterized in that: The following steps are involved: Electrodepositing aniline on the working electrode surface of the screen-printed electrode to obtain electrodeposited polyaniline; Preparation of MoS2 and Cu3Pt; The MoS2 and the Cu3Pt are sequentially subjected to oscillation mixing and centrifugal washing and then dispersed in 3 mL of ultrapure water to obtain a MoS2@Cu3PtNPs mixed solution; The MoS2@Cu3PtNPs mixed solution is added dropwise onto the surface of the modified electrode on which the polyaniline is electrodeposited, and dried at a constant temperature in a constant temperature incubator; Rinse the electrode with ultrapure water; Taking PG I antibody and dropping it onto the washed electrode until the PG I antibody is completely fixed; 1% bovine serum albumin was dropped onto the electrode surface and incubated for 30 minutes to obtain an electrochemical immunosensor.

2. The method for preparing an electrochemical immunosensor for detecting PGⅠ protein according to claim 1, characterized in that: The method of electrodepositing aniline on the working electrode surface of the screen-printed electrode to obtain the electrodeposited polyaniline comprises: Dissolve 0.15 M aniline in ultrapure water, then add 0.5 M H2SO4 and mix well to obtain an aniline solution; 50 μL of the aniline solution was dropped onto the working electrode surface of the screen-printed electrode, and the electrode surface was cyclically scanned 15 times in the range of -0.2V to 1.1V at a rate of 50 mV / s to obtain electrodeposited polyaniline.

3. The method for preparing an electrochemical immunosensor for detecting PGⅠ protein according to claim 2, characterized in that: The preparation of MoS2 comprises: Take 1.24g of ammonium heptamolybdate (NH4)6Mo7O 24 4H2O was dissolved in 15mL ultrapure water, followed by the addition of 1.67g aniline. After complete dissolution, 1M HCl was added dropwise under magnetic stirring at room temperature until a white precipitate appeared. The mixture was placed in a constant temperature incubator at 50°C for 2h to obtain a solution product. The solution product is filtered, washed with ethanol and dried at 50° C. to obtain MoO3; 0.1 g of MoO3 was dissolved in 20 mL of ultrapure water and ultrasonicated for 5 min until the MoO3 was completely dissolved to obtain a first solution; Add 0.28 g of L-cysteine ​​to the first solution during stirring to obtain a second solution; The obtained second dissolved liquid was transferred into a high-pressure reactor, reacted at 200°C for 14 hours, cooled to room temperature in the furnace, taken out, centrifuged, washed, dried at 50°C and ground to obtain MoS2.

4. The method for preparing an electrochemical immunosensor for detecting PGⅠ protein according to claim 3, characterized in that: The preparation of Cu3Pt comprises: At 60°C, add 160 mg of CTAC to 20 mL of oleylamine solution and stir to obtain a homogeneous solution; 16 mg of Pt(acac)2, 7 mg of CuCl2·H2O and 61 mg of Tris solution were sequentially added to the homogeneous solution and stirred to obtain a polymerization solution; The polymerization solution was ultrasonicated for 30 minutes and then transferred into an autoclave, heated at 180° C. for 10 hours, cooled to room temperature in the oven, taken out, washed by centrifugation with ethanol and cyclohexane, and dried at 60° C. to obtain Cu3PtNPs.

5. The method for preparing an electrochemical immunosensor for detecting PGⅠ protein according to claim 4, characterized in that: The MoS2 and Cu3Pt are sequentially subjected to oscillation mixing and centrifugal washing and then dispersed in 3 mL of ultrapure water to obtain a MoS2@Cu3PtNPs mixed solution. include: Mix 1 mL of the MoS2 with 2.5 mL of the Cu3Pt to obtain a mixed solution; The mixed solution was shaken at a low speed for 12 h in the dark, then centrifuged and washed and dispersed in 3 mL of ultrapure water to obtain a MoS2@Cu3PtNPs mixed solution.

6. An electrochemical immunosensor for detecting PGⅠ protein, prepared by the method for preparing an electrochemical immunosensor for detecting PGⅠ protein according to claim 5, characterized in that: Includes screen-printed electrodes, MoS2, Cu3Pt, PG I antibody and bovine serum albumin.

7. An application of an electrochemical immunosensor for detecting PGⅠ protein, using the electrochemical immunosensor for detecting PGⅠ protein according to claim 6, characterized in that: Applied to PGⅠ detection.

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