Kit for rapid detection of aflatoxin b1 based on catalytic characteristics of gold-platinum alloy nanoparticles and application

Abstract

The application discloses a kit for rapidly detecting aflatoxin B1 based on catalytic characteristics of gold-platinum alloy nanoparticles and application, and the kit comprises a test strip, Apt / Au-Pt NPs detection probe dispersion and hydrogen peroxide aqueous solution; the test strip comprises a bottom plate, a sample absorption pad, a nitrocellulose membrane and a water absorption pad; the nitrocellulose membrane is coated with SA / Biotin-cDNA and SA / Biotin-DNA1; the Apt / Au-Pt NPs detection probe is formed by combining SH-Apt with Au-Pt NPs through Au-S bonds after reducing disulfide bonds of the SH-Apt with tris(2-formylethyl) phosphine hydrochloride. The kit can rapidly detect aflatoxin B1 through changes of air pressure values, and has the advantages of high detection sensitivity, strong specificity, simplicity, convenience and accurate quantification.

Description

Technical Field

[0001] This invention belongs to the field of aflatoxin detection technology, specifically relating to a rapid detection kit for aflatoxin B1. This kit utilizes an aptamer labeled with gold-platinum alloy nanoparticles (denoted as Apt / Au-Pt NPs detection probe) and, combined with a handheld barometer, enables portable and rapid detection of aflatoxin B1. Background Technology

[0002] Mycotoxins are widely distributed in cereals and other food crops. Globally, approximately 25% of food crops are contaminated with mycotoxins, rendering large quantities of food inedible and posing a serious threat to human health. Mycotoxins mainly include ochratoxin, aflatoxin, zearalenone, and vomitoxin. Among these, aflatoxin B1 is the most toxic and carcinogenic. Aflatoxin B1 is stable, and conventional processing methods cannot completely remove it from food. Therefore, establishing a simple, rapid, and effective method for detecting aflatoxin B1 is of great significance for ensuring food safety and human health.

[0003] Traditional methods for detecting aflatoxin B1 include gas chromatography, liquid chromatography, liquid chromatography-mass spectrometry, and enzyme-linked immunosorbent assay (ELISA). These methods offer advantages such as high sensitivity and accuracy. However, they also suffer from drawbacks such as requiring large instruments, complex operation, high costs, and specialized operators, making them unsuitable for rapid on-site detection in large-scale production. Therefore, there is an urgent need to develop a portable, simple, and rapid method for detecting aflatoxin B1. Summary of the Invention

[0004] The purpose of this invention is to provide a kit for rapid detection of aflatoxin B1 based on the catalytic properties of gold-platinum alloy nanoparticles, and a method for rapid detection of aflatoxin B1 using this kit.

[0005] The kit for rapid detection of aflatoxin B1 based on the catalytic properties of gold-platinum alloy nanoparticles provided by this invention includes test strips, Apt / Au-Pt NPs detection probe dispersion, and hydrogen peroxide aqueous solution.

[0006] The test strip includes a base plate and, sequentially fixed on the base plate, a sample absorption pad, a nitrocellulose membrane, and an absorbent pad. The nitrocellulose membrane has a detection zone and a control zone. The detection zone is coated with a complex of streptavidin (SA) and biotinylated aflatoxin B1 aptamer complementary nucleotide 1, and the control zone is coated with a complex of streptavidin and biotinylated aflatoxin B1 aptamer complementary nucleotide 2. Biotinylated aflatoxin B1 aptamer complementary nucleotide 1 is Biotin-cDNA, and biotinylated aflatoxin B1 aptamer complementary nucleotide 2 is Biotin-DNA1. The nucleotide sequence of the Biotin-cDNA is: Biotin-AGACACAGAGAGACAA, and the nucleotide sequence of the Biotin-DNA1 is: Biotin-AAAAA AAAAAA.

[0007] The aforementioned Apt / Au-Pt NPs detection probe dispersion is formed by dispersing the Apt / Au-Pt NPs detection probe in Tris-HCl buffer. The Apt / Au-Pt NPs detection probe is formed by reducing the disulfide bond of a thiolized aflatoxin B1 aptamer with tris(2-formylethyl)phosphonic acid hydrochloride and then binding it to gold-platinum alloy nanoparticles (Au-Pt NPs) via Au-S bonds. The thiolized aflatoxin B1 aptamer is SH-Apt. The nucleotide sequence of SH-Apt is: SH-TTTTTTTTTTGGGCACGTGTTGTCTCTCTGTGTCTCGTG CCC. SH-Apt can bind to the aforementioned Biotin-cDNA and Biotin-DNA1, respectively.

[0008] Furthermore, in the above kit, it is preferred that the concentration of Apt in the Apt / Au-Pt NPs detection probe dispersion is 20-25 μM and the concentration of Au-Pt NPs is 40-50 μg / mL.

[0009] The above-mentioned Au-Pt NPs are prepared as follows: a 2% to 3% (v / v) aqueous solution of chloroauric acid is heated to boiling under magnetic stirring, then trisodium citrate is added and stirred continuously until the solution turns wine red. After cooling naturally to room temperature, chloroplatinic acid is added and heated to 75 to 80°C under magnetic stirring. Ascorbic acid is then added and stirred for 25 to 30 minutes. After cooling naturally to room temperature, the gold-platinum alloy nanoparticles Au-Pt NPs are obtained after centrifugation and washing and stored at 4 to 6°C.

[0010] Furthermore, in the above-mentioned method for preparing Au-Pt NPs, the preferred molar ratio of chloroauric acid to trisodium citrate, chloroplatinic acid, and ascorbic acid is 1:3-4:0.4-0.7:9-11.

[0011] Furthermore, in the above-mentioned kit, the mass concentration of hydrogen peroxide in the hydrogen peroxide aqueous solution is preferably 25% to 30%.

[0012] Furthermore, in the above kit, the nitrocellulose membrane is preferably CN140.

[0013] This invention also provides the application of the above-mentioned kit in the detection of aflatoxin B1.

[0014] The method for detecting aflatoxin B1 (AFB1) using the kit of the present invention includes the following steps:

[0015] Step 1: Add aflatoxin B1 aqueous solutions of different concentrations to the Apt / Au-Pt NPs detection probe dispersion and incubate at room temperature for 5-10 minutes to obtain the test solution; drop the test solution onto the sample absorption pad of the test strip and incubate at room temperature for 3-5 minutes; then cut off the detection area of ​​the test strip and place it in a sealed bottle containing hydrogen peroxide aqueous solution, incubate at room temperature for 20-25 minutes, and record the change in pressure inside the bottle using a barometer. Plot a standard curve with the logarithm of aflatoxin B1 concentration as the x-axis and the change in pressure inside the bottle as the y-axis.

[0016] Step 2: Add the sample to be tested to the Apt / Au-Pt NPs detection probe dispersion and incubate at room temperature for 5-10 minutes to obtain the sample solution; drop the sample solution onto the sample absorption pad of the test strip and incubate at room temperature for 3-5 minutes; then cut off the detection area of ​​the test strip and place it in a sealed bottle containing hydrogen peroxide solution, incubate at room temperature for 20-25 minutes, record the change in air pressure inside the bottle using a barometer, and calculate the concentration of aflatoxin B1 in the sample by combining it with the standard curve established in Step 1.

[0017] This invention improves the synthesis method of gold-platinum alloy nanoparticles to enhance their peroxidase-like activity. Then, a thiol-modified aflatoxin B1 aptamer is bound to the gold-platinum alloy nanoparticles via Au-S bonds, thus constructing an Apt / Au-Pt NPs detection probe. In this invention, the detection and control zones of the nitrocellulose membrane on the test strip are respectively coated with a complex of streptavidin and biotin-modified complementary DNA strands. This is achieved through the interaction between streptavidin and biotin, binding the complementary DNA strands to SA / Biotin-cDNA and SA / Biotin-DNA1, respectively. SA / Biotin-cDNA and SA / Biotin-DNA1 are then immobilized on the detection and control zones of the nitrocellulose membrane using a membrane application apparatus. When the Apt / Au-Pt NPs detection probe is present, Apt binds to the complementary DNA strands through base pairing, thereby capturing the detection probe in the detection zone. When aflatoxin B1 is present, it competes with the complementary DNA strand in the detection region for binding to the detection probe, causing the probe to detach from the detection region. This results in a reduction of the Apt / Au-Pt NPs detection probe in the detection region. Since the gold-platinum alloy nanoparticles possess peroxidase-like activity, they can catalyze the decomposition of hydrogen peroxide to produce oxygen, causing a change in the system pressure. Therefore, by using a handheld barometer to detect the system pressure, aflatoxin B1 can be rapidly detected through changes in pressure.

[0018] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0019] 1. This invention optimizes the synthesis method of gold-platinum alloy nanoparticles in the Apt / Au-Pt NPs detection probe, improves the peroxidase-like activity of the gold-platinum alloy nanoparticles, and enhances the analytical sensitivity and efficiency of aflatoxin B1 analysis.

[0020] 2. In the kit of the present invention, aflatoxin B1 competes with the complementary DNA strand in the detection area of ​​the test strip for binding to the Apt / Au-Pt NPs detection probe, resulting in a reduction of gold-platinum alloy nanoparticles in the detection area. The peroxidase-like activity of the gold-platinum alloy nanoparticles causes a change in the gas pressure of the experimental system, so that aflatoxin B1 can be accurately quantified using only a barometer without the need for complex precision instruments.

[0021] 3. The kit of the present invention has the advantages of high sensitivity, strong specificity, simplicity and convenience, and accurate quantification for the detection of aflatoxin B1. Attached Figure Description

[0022] Figure 1 This is a schematic diagram illustrating the principle of a visual method for detecting aflatoxin B1.

[0023] Figure 2 Here are transmission electron micrographs (A) and histograms (B) of Au-Pt NPs.

[0024] Figure 3 This is an elemental distribution diagram of Au-Pt NPs powder.

[0025] Figure 4 The images show the overall X-ray photoelectron spectrum (A), the Au 4f X-ray photoelectron spectrum (B), and the Pt 4f X-ray photoelectron spectrum (C) of Au-Pt NPs powder.

[0026] Figure 5 This is a graph showing the pressure changes after different nanomaterials catalyze hydrogen peroxide.

[0027] Figure 6 This is a graph showing the pressure changes after different Au-Pt NPs catalyze hydrogen peroxide.

[0028] Figure 7 It is the UV absorption of the Apt / Au-Pt NPs detection probe dispersion and pure water.

[0029] Figure 8 The pressure change of the system in the presence of different concentrations of AFB1 (A), and the linear relationship between ΔP and AFB1 concentration in the range of 1–500 ng / mL (B).

[0030] Figure 9 This describes the system's response in the presence of different mycotoxins. Detailed Implementation

[0031] The present invention will be further described in detail below with reference to the accompanying drawings and embodiments, but the scope of protection of the present invention is not limited to these embodiments.

[0032] The detection principle of this invention is as follows: Figure 1As shown, a mixture of sample and Apt / Au-Pt NPs detection probe dispersion is added to the sample absorption pad. When the sample does not contain aflatoxin B1, as the test solution flows to the detection zone of the nitrocellulose membrane, the Biotin-cDNA in the detection zone binds to the Apt bases on the Apt / Au-Pt NPs detection probe, thus immobilizing the Apt / Au-Pt NPs detection probe in the detection zone. When the test solution flows to the control zone of the nitrocellulose membrane, the Biotin-DNA1 in the control zone binds to the remaining Apt bases on the Apt / Au-Pt NPs detection probe, thus immobilizing the Apt / Au-Pt NPs detection probe in the control zone. Because Au-Pt NPs have peroxidase-like activity, they can catalyze the production of oxygen from hydrogen peroxide. Therefore, after cutting off the detection zone or control zone and placing it in a sealed bottle containing an aqueous hydrogen peroxide solution, the pressure inside the bottle gradually increases over time. When a sample contains aflatoxin B1, it competes with the Biotin-cDNA in the nitrocellulose membrane detection zone for binding to the Apt / Au-Pt NPs detection probe. Because aflatoxin B1 has a stronger binding affinity to the Apt / Au-Pt NPs detection probe, the more aflatoxin B1 present, the less Apt / Au-Pt NPs detection probe binds to the Biotin-cDNA in the detection zone. However, the binding of the Biotin-DNA1 in the control zone to the Apt / Au-Pt NPs detection probe is unaffected by aflatoxin B1. Therefore, when the detection zone is cut and placed in a sealed bottle containing a 25%–30% hydrogen peroxide solution, the pressure change within the bottle decreases with increasing aflatoxin B1 concentration in the sample, while the pressure inside the bottle containing the control zone remains stable and does not change with the aflatoxin B1 content. Therefore, the content of aflatoxin B1 in the sample is detected by measuring the change in air pressure inside the bottle in the detection zone.

[0033] Example 1

[0034] The kit for detecting aflatoxin B1 in this embodiment includes test strips, Apt / Au-Pt NPs detection probe dispersion, and a 30% hydrogen peroxide aqueous solution.

[0035] The test strip includes a base plate and a sample absorption pad, a nitrocellulose membrane, and an absorbent pad that are sequentially attached and fixed to the base plate. The nitrocellulose membrane is CN140, and it has a detection area and a quality control area.

[0036] The detection region is coated with a complex of streptavidin (SA) and biotinylated aflatoxin B1 aptamer complementary nucleotide 1. Biotinylated aflatoxin B1 aptamer complementary nucleotide 1 is Biotin-cDNA, and its nucleotide sequence is Biotin-AGACACAGAGAGACAA. The specific preparation method for the detection region is as follows: 300 μL of 5 μM biotinylated aflatoxin B1 aptamer complementary nucleotide 1, 120 μL of 50 μg / mL SA, and 180 μL of 10 mM PBS buffer are mixed and incubated at 37°C for 1 h to obtain the SA-Biotin-cDNA complex; then, the SA-Biotin-cDNA complex is immobilized on the detection region of a nitrocellulose membrane using an HM3035 membrane scrubber at a speed of 2 μL / cm.

[0037] The quality control region is coated with a complex of streptavidin and biotinylated aflatoxin B1 aptamer complementary nucleotide 2, which is Biotin-DNA1 with the nucleotide sequence Biotin-AAAAAAAAAAA. The specific preparation method of the quality control region is as follows: 300 μL of 5 μM biotinylated aflatoxin B1 aptamer complementary nucleotide 2, 120 μL of 50 μg / mL SA, and 180 μL of 10 mM PBS buffer are mixed and incubated at 37°C for 1 h to obtain the SA-Biotin-DNA1 complex; then, the SA-Biotin-DNA1 complex is immobilized on the quality control region of a nitrocellulose membrane using an HM3035 membrane scrubbing apparatus at a speed of 2 μL / cm.

[0038] The Apt / Au-Pt NPs detection probe dispersion is formed by dispersing the Apt / Au-Pt NPs detection probe in Tris-HCl buffer. The Apt / Au-Pt NPs detection probe is formed by reducing the disulfide bond of a thiolized aflatoxin B1 aptamer with tris(2-formylethyl)phosphonic acid hydrochloride and then binding it to gold-platinum alloy nanoparticles Au-Pt NPs via Au-S bonds. The thiolized aflatoxin B1 aptamer is SH-Apt. The nucleotide sequence of SH-Apt is: SH-TTTTTTTTTTGGGCACGTGTTGTCTCTCTGTGTCTCGTGCCC. The preparation method of the Apt / Au-Pt NPs detection probe dispersion includes the following steps:

[0039] Step 1: Preparation of Au-Pt NPs dispersion

[0040] Add 2 mL of 25 mM chloroauric acid trihydrate aqueous solution to 193 mL of water, heat to boiling with magnetic stirring, then add 5 mL of 39 mM trisodium citrate aqueous solution, and continue stirring for 45 min until the solution turns wine red. Allow to cool naturally to room temperature, centrifuge and wash to obtain a gold nanoparticle (Au NPs) solution. Take the above Au NPs solution, add 25 mL of 1 mM chloroplatinic acid aqueous solution, heat to 80 °C with magnetic stirring, then add 50 mL of 10 mM ascorbic acid aqueous solution at a rate of 5 mL / min, stir for 30 min, allow to cool naturally to room temperature, centrifuge and wash to obtain an Au-Pt NPs dispersion, and store at 4 °C.

[0041] Step 2: Preparation of Apt / Au-Pt NPs detection probe dispersion

[0042] 100 μL of SH-Apt was mixed with 5 μL of 2.0 mM tris(2-formylethyl)phosphonic acid hydrochloride aqueous solution for 30 min. The resulting mixture was then added dropwise to 1 mL of Au-Pt NPs dispersion and incubated in the dark for 12 h to allow SH-Apt and Au-Pt NPs to bind via Au-S bonds. Finally, the mixture was centrifuged and dispersed in Tris-HCl buffer to obtain the Apt / Au-Pt NPs detection probe dispersion, which was stored at 4 °C. The concentration of Apt in the Apt / Au-Pt NPs detection probe dispersion was 24 μM, and the concentration of Au-Pt NPs was 45 μg / mL.

[0043] The morphology of the above Au-Pt NPs was characterized by high-resolution transmission electron microscopy, and the results are as follows: Figure 2 As shown in Figure A, Au-Pt NPs are spherical particles with uniform distribution and size. Statistical analysis of their particle size revealed that their size ranges from 12 to 17 nm, and they generally follow a normal distribution. Figure 2 B), with an average size of 14.5 ± 0.5 nm. The elemental distribution of Au-Pt NPs was analyzed by X-ray energy-dispersive X-ray spectroscopy, and the results... Figure 3 As shown, Figure 3 A represents the distribution of Au-Pt NPs. Figure 3 B and Figure 3 D represents the distribution of Au and Pt elements, which are uniformly distributed throughout the nanoparticle. Figure 3 C is to Figure 3 The composite image formed by superimposing A, B, and D. Figure 3The yellow color in C is a composite color of green (Au) and red (Pt), indicating that both Au and Pt elements are distributed in the nanoparticles, without a situation where Au or Pt is more widely distributed. This proves that the synthesized nanoparticles are Au-Pt alloy nanoparticles (Au-Pt NPs). The elemental composition and elemental states of the synthesized material were further characterized using X-ray photoelectron spectroscopy, such as... Figure 4 As shown in Figure A, the characteristic peaks at 532.2 eV, 286.4 eV, 84.1 eV, and 73.8 eV in the XPS full spectrum of Au-Pt NPs are assigned to O1s, C1s, Au 4f, and Pt 4f, respectively. Peak fitting was performed on the Au 4f spectrum. Figure 4 B), the peaks at binding energies of 84.1 eV and 87.6 eV correspond to characteristic peaks of Au, further proving the presence of Au. In the fitted peak spectrum of Pt 4f ( Figure 4 C) The peaks at 71.1 eV and 74.3 eV are characteristic peaks of elemental Pt, indicating the presence of Pt. Au-Pt NPs possess peroxidase-like activity, meaning they can catalyze the production of oxygen from hydrogen peroxide. Therefore, the peroxidase-like activity of the synthesized Au-Pt NPs was verified, as shown in the figure. Figure 5 As shown, Au NPs, Pt NPs, and Au-Pt NPs all possess peroxidase-like activity. However, under the same conditions, Au-Pt NPs exhibit stronger peroxidase-like activity. The amount of oxygen produced by Au-Pt NPs catalyzing hydrogen peroxide within the same time frame is significantly higher than that of Au NPs and Pt NPs. Therefore, Au-Pt NPs, with their stronger peroxidase-like activity, are chosen to achieve higher detection performance. However, the synthesis method of Au-Pt NPs has a certain impact on their peroxidase-like activity, such as… Figure 6 As shown, Au-Pt NPs-1 are nanoparticles synthesized using a conventional one-step synthesis method, while Au-Pt NPs-2 are synthesized using the method provided in this embodiment. Compared to conventional methods, the Au-Pt NPs synthesized by the method of this invention are uniformly sized spherical particles and exhibit stronger peroxidase-like activity. Furthermore, ultraviolet spectroscopy was performed on Apt / Au-Pt NPs in the wavelength range of 200–500 nm, and the results are as follows. Figure 7 As shown, a distinct UV absorption peak exists only when the aptamer chain (Apt) is present, i.e. when the Apt / Au-PtNPs detection probe is successfully prepared. This is due to the absorption of UV light by the conjugated double bond system of the purine and pyrimidine rings in the aptamer chain.

[0044] Example 2

[0045] The application of the kit in Example 1 for portable rapid detection of AFB1 is as follows:

[0046] Step 1: Plot the standard curve

[0047] Add aflatoxin B1 aqueous solutions of different concentrations to 1 mL of Apt / Au-Pt NPs detection probe dispersion and incubate at room temperature for 5 min to obtain the test solution. Add the test solution dropwise onto the sample absorption pad of the test strip and incubate at room temperature for 5 min. Then cut off the detection area of ​​the test strip and place it in a sealed bottle containing 400 μL of 30% hydrogen peroxide aqueous solution. Incubate for 20 min, and record the change in pressure inside the bottle using an HT-1895 barometer. Plot a standard curve with the logarithm of aflatoxin B1 concentration on the x-axis and the change in pressure inside the bottle on the y-axis.

[0048] Depend on Figure 8 A and Figure 8 As shown in B, within the concentration range of 1–500 ng / mL, the gas pressure inside the bottle gradually decreases with increasing AFB1 concentration, and the AFB1 concentration shows a good linear relationship with the pressure change (ΔP), with the linear equation being ΔP = 17.455lg(C). AFB1 +3.110, correlation coefficient (R) 2 The value was 0.997, and the calculated limit of detection was 0.25 ng / mL (LOD = 3σ / K).

[0049] Step 2: Detect AFB1 in the sample

[0050] Add the sample to be tested to the Apt / Au-Pt NPs detection probe dispersion and incubate at room temperature for 5 minutes to obtain the sample solution. Add the sample solution dropwise onto the sample absorption pad of the test strip and incubate at room temperature for 3 minutes. Then cut off the detection area of ​​the test strip and place it in a sealed bottle containing hydrogen peroxide solution. Incubate at room temperature for 20 minutes. Record the change in pressure inside the bottle using a barometer. Calculate the concentration of aflatoxin B1 in the sample using the standard curve established in step 1. The specific experiment is as follows:

[0051] Peanut and corn samples were pulverized using a high-speed pulverizer and passed through a 32-mesh sieve. Then, 5.00g of each sample was placed in a 50mL centrifuge tube, and 20mL of a methanol-water mixture with a volume ratio of 7:3 was added. The mixture was vortexed and extracted in a shaker for 20min. After centrifugation at 6000r / min for 10min, the supernatant was collected and the performance of this method in the detection of AFB1 in actual samples was evaluated using the spiked recovery method. The results of this method were compared with those of the national standard method (high performance liquid chromatography), as shown in Table 1.

[0052] Table 1. Detection results of AFB1 in samples by this method and high performance liquid chromatography.

[0053]

[0054] As shown in Table 1, the recovery rate of the method of the present invention is 92.2%–104.8% (relative standard deviation (RSD) of 1.1%–4.9%); the recovery rate of the high performance liquid chromatography (HPLC) method is 96.9%–105.3% (relative standard deviation (RSD) of 1.1%–3.7%). The detection results of the method of the present invention and the HPLC method are largely consistent, indicating that the detection method of the present invention has high accuracy.

[0055] To further demonstrate the specificity of the kit for detecting AFB1, other mycotoxins were selected as control groups, with the concentration of mycotoxins in each control group being ten times that of the AFB1 group. The specific experiments are as follows:

[0056] Add 10 μL of aqueous solutions of different fungal toxins (ochratoxin A (OTA), zearalenone (ZEN), vomitoxin (DON), and aflatoxin B2 (AFB2) at a concentration of 500 ng / mL, and AFB1 at a concentration of 50 ng / mL) to 1 mL of Apt / Au-PtNPs detection probe dispersion. Incubate at room temperature for 5 min to obtain the test solution. Drop the test solution onto the sample pad of the test strip and incubate at room temperature for 5 min. Then cut off the detection area of ​​the test strip and place it in a sealed bottle containing 400 μL of 30% hydrogen peroxide aqueous solution. Incubate for 20 min and record the change in pressure inside the bottle using an HT-1895 barometer.

[0057] Depend on Figure 9 As can be seen, the signal value of the AFB1 group is much larger than that of the OTA, ZEN, DON, and AFB2 groups, and there is a significant difference. This indicates that other toxins do not interfere with the method, and that the kit of the present invention has good selectivity for detecting AFB1.

Claims

1. A kit for rapid detection of aflatoxin B1 based on catalytic properties of gold-platinum alloy nanoparticles, characterized by: The kit comprises a test strip, an Apt / Au-Pt NPs detection probe dispersion liquid, and a hydrogen peroxide aqueous solution. The test strip comprises a base plate and a sample absorption pad, a nitrocellulose membrane, and a water absorption pad fixed on the base plate in sequence; the nitrocellulose membrane is provided with a detection zone and a quality control zone; the detection zone is coated with a complex of streptavidin and biotinylated aflatoxin B1 aptamer complementary nucleotide 1, and the quality control zone is coated with a complex of streptavidin and biotinylated aflatoxin B1 aptamer complementary nucleotide 2; the biotinylated aflatoxin B1 aptamer complementary nucleotide 1 is Biotin-cDNA, and the biotinylated aflatoxin B1 aptamer complementary nucleotide 2 is Biotin-DNA1; the nucleotide sequence of the Biotin-cDNA is Biotin-AGACACAGAGAGACAA, and the nucleotide sequence of the Biotin-DNA1 is Biotin-AAAAAAAAAAA; The Apt / Au-Pt NPs detection probe dispersion liquid is formed by dispersing an Apt / Au-Pt NPs detection probe in a Tris-HCl buffer solution; the Apt / Au-Pt NPs detection probe is formed by binding a thiolated aflatoxin B1 aptamer and gold-platinum alloy nanoparticles Au-Pt NPs through an Au-S bond after reducing disulfide bonds of the thiolated aflatoxin B1 aptamer with tris(2-formylethyl) phosphine hydrochloride; the thiolated aflatoxin B1 aptamer is SH-Apt; the nucleotide sequence of the SH-Apt is SH-TTTTTTTTTTGGGCACGTGTTGTCTCTCTGTGTCTCGTGCCC; The gold-platinum alloy nanoparticles Au-Pt NPs are prepared by the following method: an aqueous solution of chloroauric acid is heated to boiling under magnetic stirring, then trisodium citrate is added, and the solution is continuously stirred until it turns wine red, and then naturally cooled to room temperature; chloroplatinic acid is added, and the solution is heated to 75-80 DEG C under magnetic stirring; then ascorbic acid is added, and the solution is stirred for 25-30 minutes, and then naturally cooled to room temperature; the gold-platinum alloy nanoparticles Au-Pt NPs are obtained by centrifugal washing, and stored at 4-6 DEG C; wherein the molar ratio of the chloroauric acid to the trisodium citrate, the chloroplatinic acid, and the ascorbic acid is 1:3-4:0.4-0.7:9-11.

2. The kit for rapid detection of aflatoxin B1 based on catalytic properties of gold-platinum alloy nanoparticles according to claim 1, characterized in that: The concentration of Apt in the Apt / Au-Pt NPs detection probe dispersion liquid is 20-25 μM, and the concentration of Au-Pt NPs is 40-50 μg / mL.

3. The kit for rapid detection of aflatoxin B1 based on catalytic properties of gold-platinum alloy nanoparticles according to claim 1, characterized in that: The mass concentration of hydrogen peroxide in the hydrogen peroxide aqueous solution is 25%-30%.

4. The kit for rapid detection of aflatoxin B1 based on catalytic properties of gold-platinum alloy nanoparticles according to claim 1, characterized in that: The nitrocellulose membrane is CN140.

5. The kit of any one of claims 1-4 for detecting aflatoxin B1.

6. The method for detecting aflatoxin B1 using the kit according to any one of claims 1 to 4, characterized by: The kit comprises the following steps: Step 1: Add different concentrations of aflatoxin B1 aqueous solution into the Apt / Au-Pt NPs detection probe dispersion, and incubate at room temperature for 5-10 minutes to obtain the test solution; drop the test solution on the sample absorption pad of the test strip, and incubate at room temperature for 3-5 minutes; then cut the detection area of the test strip and put it into a sealed bottle containing hydrogen peroxide aqueous solution, and incubate at room temperature for 20-25 minutes; use a barometer to record the change of the gas pressure in the bottle, and draw a standard curve with the logarithmic value of the concentration of aflatoxin B1 as the abscissa and the change of the gas pressure in the bottle as the ordinate; Step 2: Add the test sample into the Apt / Au-Pt NPs detection probe dispersion, and incubate at room temperature for 5-10 minutes to obtain the sample solution; drop the sample solution on the sample absorption pad of the test strip, and incubate at room temperature for 3-5 minutes; then cut the detection area of the test strip and put it into a sealed bottle containing hydrogen peroxide aqueous solution, and incubate at room temperature for 20-25 minutes; use a barometer to record the change of the gas pressure in the bottle, and calculate the concentration of aflatoxin B1 in the test sample by combining the standard curve prepared in step 1.

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