Preparation method and application of electrochemical luminescence sensor based on MXene quantum dot and tin disulfide

Abstract

The invention discloses a preparation method and application of an electrochemical luminescence sensor based on MXene quantum dots and tin disulfide, and belongs to the technical field of food safety detection. The preparation method of the electrochemical luminescence sensor comprises the following steps: preparing the Ti < 3 > C < 2 > T < x > quantum dot, preparing the Ti < 3 > C < 2 > T < x > quantum dot (at) SnS < 2 > and preparing the electrochemical luminescence sensor. An electrochemical luminescence group is synthesized by a high-temperature heating method and is used for constructing an electrochemical luminescence sensor; the manufacturing environment and the manufacturing method are easy to implement. According to the present invention, the Ti3C2Tx quantum dot (at) SnS2 is adopted as the electrochemical luminescence group to construct the electrochemical luminescence sensor so as to detect aflatoxin B1, and specifically, the S vacancy modified Ti3C2Tx quantum dot is introduced as the efficient electrochemical luminescence group so as to further construct the electrochemical luminescence sensing platform; the concentration of the aflatoxin B1 can be accurately and rapidly detected.

Description

Technical Field

[0001] The present invention belongs to the technical field of food safety detection, and more specifically relates to a preparation method and application of an electrochemiluminescence sensor based on MXene quantum dots @ tin disulfide. Background Art

[0002] Fresh fish can be eaten directly or processed into dried fish products, providing a unique flavor for storage and commercial sales. Nevertheless, more and more studies have reported that dried fish products are extremely vulnerable to mycotoxin contamination during processing and storage, especially aflatoxin B1 (AFB1), with a maximum contamination rate of 56%. AFB1 is one of the secondary metabolites of Aspergillus, mainly produced by Aspergillus flavus and Aspergillus parasiticus, and is the most toxic aflatoxin. It has been listed as a class I carcinogen by the International Agency for Research on Cancer (IARC). Therefore, designing an analytical method for accurately, efficiently, rapidly, and sensitively detecting AFB1 in food is crucial for ensuring food safety and public health.

[0003] Electrochemiluminescence (ECL), also known as electrogenerated chemiluminescence, is the best combination of electrochemistry and spectroscopy. It involves the luminescence phenomenon emitted by materials in the excited state, which is generated by electron transfer on the electrode surface and then returns from the excited state to the ground state. ECL has the characteristics of high sensitivity, short detection time, and low background interference, and has great application potential in food safety, environmental monitoring, and bioanalysis. The improvement of ECL performance depends on the development of high-performance emitters. From traditional luminescent materials (organic and inorganic metal complexes) to emerging ECL luminophores (aggregation-induced emission materials, metal nanoparticles, perovskite nanocrystals, and quantum dots), a series of emitters have been used to construct ECL sensors. However, traditional ECL luminophores can no longer meet the growing analytical needs due to their low solubility, poor stability, and related toxicity. At the same time, metal nanoclusters (MNCs) have become luminescent materials in the fields of biosensing and bioimaging due to their high abundance, low cost, and high biocompatibility. Despite their potential, the ECL signals of MNCs, especially the anodic signals, are still limited, which greatly restricts their wide application in ECL-based analytical methods. In addition, polycyclic aromatic hydrocarbons (PAHs), as an important aggregation-induced electrochemiluminescence material, also play a crucial role in the development of ECL nanoluminophores due to their variable structures, tunable emission wavelengths, and non-toxicity. However, due to their large planar conjugated structures and strong π-π accumulation in the aggregated state, the emission of molecules shows an aggregation-caused quenching effect (ACQ), which greatly restricts their practical applications. Summary of the Invention

[0004] The object of the present invention is to provide a preparation method and application of an electrochemiluminescence sensor based on MXene quantum dots @ tin disulfide, so as to solve the problems existing in the above-mentioned prior art, meet the detection requirements for AFB1 in food, and achieve rapid and specific detection of AFB1 contamination in food.

[0005] To achieve the above object, the present invention provides the following solutions:

[0006] One of the technical solutions of the present invention: Provide a preparation method of Ti3C2T x quantum dots @ SnS2, including the following steps:

[0007] Mix Ti3C2T x quantum dots, a sulfur source, a tin source and a solvent, and then perform heat treatment. Take the precipitate to obtain the Ti3C2T x quantum dots @ SnS2.

[0008] Preferably, the preparation steps of the Ti3C2T x quantum dots include: Mix the Ti3C2T x solution and the tetramethylammonium hydroxide solution and then react. Centrifuge to obtain the precipitate. Mix the precipitate and water and treat at 0-5 °C for 1-3 h. Take the supernatant and adjust its pH value to 8-10, and heat to 100-150 °C for 4-8 h to obtain the Ti3C2T x quantum dots.

[0009] Preferably, the preparation steps of the Ti3C2T x solution include: Add Ti3C2T2 to the mixed solution of hydrochloric acid and lithium fluoride and react at 30-50 °C for 18-30 h to obtain the Ti3C2T x solution.

[0010] Preferably, the dosage ratio of the hydrochloric acid, lithium fluoride, Ti3AlC2 and tetramethylammonium hydroxide solution is 10-30 mL: 0.8-3 g: 0.5-2 g: 30-60 mL; the mass fraction of the tetramethylammonium hydroxide solution is 25%.

[0011] Preferably, the sulfur source includes thioacetamide; the tin source includes tin chloride; the solvent includes isopropanol and / or ethanol; the dosage ratio of the sulfur source, tin source, solvent and Ti3C2T x quantum dots is 0.15-0.4 g: 0.1-0.35 g: 8-25 mL: 0.05-0.2 g.

[0012] Preferably, the temperature of the heat treatment is 150-180 °C and the time is 18-24 h.

[0013] The second technical solution of the present invention: providing Ti3C2T x Quantum dots@SnS2 prepared by the above preparation method.

[0014] The third technical solution of the present invention: providing the application of the above Ti3C2T x Quantum dots@SnS2 in the preparation of an electrochemiluminescence sensor.

[0015] The fourth technical solution of the present invention: providing an electrochemiluminescence sensor based on Ti3C2T x Quantum dots@SnS2, and the electrochemiluminescence sensor is prepared by using the above Ti3C2T x Quantum dots@SnS2.

[0016] The fifth technical solution of the present invention: providing a preparation method of the above electrochemiluminescence sensor based on Ti3C2T x Quantum dots@SnS2, comprising the following steps:

[0017] Using ITO as the working electrode, performing electrodeposition in a chloroauric acid solution to obtain AuNPs / ITO; incubating AuNPs / ITO successively in SH-cDNA, 6-mercapto-1-hexanol, and SH-Apt-MQD@SnS2 to obtain the electrochemiluminescence sensor based on Ti3C2T x Quantum dots@SnS2;

[0018] The SH-Apt-MQD@SnS2 is prepared by a DNA probe modified with SH and the above Ti3C2T x Quantum dots@SnS2.

[0019] Preferably, the concentration of the chloroauric acid solution is 0.1-0.5 mM; the concentration of the SH-cDNA is 0.2-1 μM; the concentration of the 6-mercapto-1-hexanol is 0.05-0.1 mM; the concentration of the aptamer in the SH-Apt-MQD@SnS2 is 1-3 μM.

[0020] Preferably, the conditions for the electrodeposition are: -0.1-0.245 V, 10-100 s; the conditions for incubation in the SH-cDNA are: 25-37 °C, 1-2 h; the conditions for incubation in the 6-mercapto-1-hexanol are: 4-25 °C, 2-3 h; the conditions for incubation in the SH-Apt-MQD@SnS2 are: 25-37 °C, 3-5 h.

[0021] Preferably, the preparation steps of the SH-Apt-MQD@SnS2 include: mixing the above Ti3C2T xQuantum dots@SnS2 and SH-modified DNA probes were co-incubated for 3 h to obtain SH-Apt-MQD@SnS2; the concentration of the SH-modified DNA probes was 3 μM; the Ti3C2T x The volume ratio of quantum dots@SnS2 to SH-modified DNA probes was 1:1.

[0022] The sixth technical solution of the present invention: providing the above-mentioned electrochemical luminescence sensor based on Ti3C2T x Application of quantum dots@SnS2 in food detection, and the food detection includes detection of aflatoxin B1 in food.

[0023] The present invention also provides a method for detecting aflatoxin B1 in food, which includes the following steps:

[0024] (a) Establishment of aflatoxin B1 concentration prediction model: Based on the above-mentioned electrochemical luminescence sensor of quantum dots@SnS2, the concentration and electrochemical luminescence intensity of aflatoxin B1 standard solutions with concentrations of 0.001 - 100 ng / mL were linearly fitted to establish an aflatoxin B1 concentration prediction model; x The present invention also provides a method for detecting aflatoxin B1 in food, which includes the following steps:

[0025] (b) Detection of aflatoxin B1 concentration in food: The solution containing aflatoxin B1 in food was extracted and dropped onto the above-mentioned electrochemical luminescence sensor of quantum dots@SnS2 based on Ti3C2T, the electrochemical intensity of the electrochemical luminescence sensor of quantum dots@SnS2 based on Ti3C2T was measured, and it was substituted into the aflatoxin B1 concentration prediction model obtained in step (a) to obtain the corresponding aflatoxin B1 concentration. x Quantum dots@SnS2, and the electrochemical intensity of the electrochemical luminescence sensor of quantum dots@SnS2 based on Ti3C2T was measured and substituted into the aflatoxin B1 concentration prediction model obtained in step (a) to obtain the corresponding aflatoxin B1 concentration. x Quantum dots@SnS2, and the electrochemical intensity of the electrochemical luminescence sensor of quantum dots@SnS2 based on Ti3C2T was measured and substituted into the aflatoxin B1 concentration prediction model obtained in step (a) to obtain the corresponding aflatoxin B1 concentration.

[0026] The technical principle of the present invention is:

[0027] In the process of preparing quantum dots@SnS2 of Ti3C2T, through the specific dosage ratio of Ti3C2T x Quantum dots, thioacetamide and tin chloride, as well as reaction parameters, ensured the successful synthesis of nano-flower-like SnS2 with a relatively large specific surface area, and then successfully prepared quantum dots of Ti3C2T introduced with S vacancy modification. x Quantum dots, thioacetamide and tin chloride, as well as reaction parameters, ensured the successful synthesis of nano-flower-like SnS2 with a relatively large specific surface area, and then successfully prepared quantum dots of Ti3C2T introduced with S vacancy modification. x Quantum dots.

[0028] By introducing S vacancy-modified Ti3C2T x Quantum dots as efficient electrochemiluminescence groups, compared with the existing modified quantum dots, this quantum dot has high ECL luminescence intensity, and this quantum dot is further used to construct an electrochemiluminescence sensing platform to realize the accurate and rapid detection of AFB1 concentration.

[0029] The sensing system constructed by introducing the nucleic acid aptamer complementary strategy ensures that the electrochemical luminescence sensor has a wide detection range and a low detection limit, making this detection method have good practical prospects.

[0030] Since specific binding can occur between the nucleic acid aptamer and AFB1, when AFB1 is present, the SH-Apt-MQD@SnS2 will react with it and fall off the electrode surface, thereby causing a change in the ECL signal, and then realizing the detection of AFB1.

[0031] The present invention discloses the following technical effects:

[0032] (1) The present invention discloses a method for preparing an electrochemical luminescence sensor. Specifically, an electrochemiluminescent group is synthesized by a high-temperature heating method and used to construct an electrochemical luminescence sensor; the production environment and production method are easy to implement.

[0033] (2) The present invention discloses a method for detecting AFB1, which is based on Ti3C2T x Quantum dot@SnS2 is used as an electrochemiluminescent group to construct an electrochemical luminescence sensor for detecting AFB1. Specifically, by introducing S vacancies to modify Ti3C2T x Quantum dots as efficient electrochemiluminescent groups are further used to construct an electrochemical luminescence sensing platform; realizing the precise and rapid detection of the concentration of AFB1.

[0034] (3) The electrochemical luminescence sensor constructed by the present invention has excellent detection performance, with a wide detection range and a low detection limit, making this detection method have good practical prospects. Brief Description of the Drawings

[0035] Figure 1 Transmission electron microscope image and size distribution diagram of the Ti3C2T x Quantum dots prepared in Example 1, where (A) is the transmission electron microscope image and (B) is the size distribution diagram;

[0036] Figure 2 Electron microscope image, Mapping image and characterization image of S vacancies of the Ti3C2T x Quantum dot@SnS2 prepared in Example 1, where (A) is the electron microscope image and Mapping image, and (B) is the characterization image of S vacancies;

[0037] Figure 3 Schematic diagram of the preparation process of the electrochemical luminescence sensor based on Ti3C2T x Quantum dot@SnS2;

[0038] Figure 4 Electrochemical luminescence sensor based on Ti3C2T prepared in Example 1x Feasibility analysis results of an electrochemiluminescence sensor based on quantum dots@SnS2, where (A) is the CV diagram, (B) is the EIS diagram, and (C) is the ECL signal detection diagram at different AFB1 concentrations;

[0039] Figure 5 It is the electrochemiluminescence signal diagram of the sensor when detecting different concentrations of AFB1 in Example 1, the established standard curve, and the anti-interference experiment results of AFB1. Among them, (A) is the electrochemiluminescence signal diagram of the sensor when detecting different concentrations of AFB1 and the established standard curve, and (B) is the anti-interference experiment results of AFB1. Detailed implementation manners

[0040] Now, various exemplary implementation manners of the present invention will be described in detail. This detailed description should not be considered as a limitation of the present invention, but should be understood as a more detailed description of certain aspects, characteristics, and implementation manners of the present invention.

[0041] It should be understood that the terms described in the present invention are only for describing specific implementation manners and are not used to limit the present invention. Additionally, for the numerical ranges in the present invention, it should be understood that each intermediate value between the upper and lower limits of the range is also specifically disclosed. Any intermediate value within any stated value or stated range, as well as each smaller range between any other stated value or intermediate value within the stated range, is also included in the present invention. The upper and lower limits of these smaller ranges can be independently included or excluded from the range.

[0042] Unless otherwise specified, all technical and scientific terms used herein have the same meaning as commonly understood by those of ordinary skill in the art to which the present invention pertains. Although the present invention only describes preferred methods and materials, any methods and materials similar or equivalent to those described herein can also be used in the implementation or testing of the present invention. All documents mentioned in this specification are incorporated by reference to disclose and describe the methods and / or materials related to the documents. In case of conflict with any incorporated document, the content of this specification shall prevail.

[0043] Without departing from the scope or spirit of the present invention, various improvements and changes can be made to the specific implementation manners of the description of the present invention, which are obvious to those skilled in the art. Other implementation manners obtained from the description of the present invention are obvious to those skilled in the art. The description and examples of the present invention are only exemplary.

[0044] Regarding the use of "comprising", "including", "having", "containing", etc. in this article, they are all open-ended terms, meaning including but not limited to.

[0045] It should be noted that the aspects not described in detail in the present invention are all conventional operation means in the art and are not the focus of the present invention.

[0046] During the performance detection process of the present invention, the AFB1 detected is mainly a secondary metabolite produced by Aspergillus flavus and Aspergillus parasiticus, and is the most toxic aflatoxin.

[0047] During the performance detection process of the present invention, the dried fish sample is dried large yellow croaker, purchased from Xiamen Xiasha International Aquatic Products Trading Center.

[0048] The SH-cDNA and SH-modified DNA probes used in the following examples and comparative examples of the present invention are all purchased from Sangon Biotech (Shanghai) Co., Ltd. Other raw materials used are all commercially available products unless otherwise specified. The source of the commercially available products has no influence on the technical effects achieved by the present invention.

[0049] Unless otherwise specified, the room temperature involved in the present invention is calculated as 25±5°C.

[0050] Example 1

[0051] Step 1, preparation of Ti3C2T x Quantum dots:

[0052] Dissolve LiF (1.6 g) in HCl (20 mL, 9 M), add Ti3AlC2 (1 g), and react at 50°C for 24 h. Wash the resulting suspension with ultrapure water until the pH value of the solution is neutral (pH = 7). Add 40 mL of 25 wt% tetramethylammonium hydroxide (TMAOH) solution and stir at room temperature for 24 h. Centrifuge at 8000 r / min for 10 min to collect the precipitate. After washing the precipitate 3 times with deionized water, add 20 mL of ultrapure water and ultrasonicate in an ice bath for 1 h, then centrifuge at 3500 r / min for 10 min. Take the supernatant and perform vacuum freeze-drying to obtain MXene nanosheets. Prepare a 20 mL MXene nanosheet (5 mg / mL) solution, adjust its pH value to 9 with ammonia water, and transfer it to a 50 mL stainless steel autoclave and heat at 120°C for 6 h. Finally, filter with a 0.22 μm microporous membrane and perform freeze-drying to obtain Ti3C2T x Quantum dots;

[0053] Figure 1 For the Ti3C2T x Transmission electron microscope image and size distribution diagram of quantum dots, where (A) is the transmission electron microscope image and (B) is the size distribution diagram. Figure 1 Illustrate the successful preparation of Ti3C2T x Quantum dots;

[0054] Step 2, preparation of Ti3C2T x Quantum dots@SnS2:

[0055] Dissolve 0.27 g of SnCl4·5H2O and 0.24 g of thioacetamide in 15 mL of isopropanol and ultrasonicate for 10 min. Then, add 0.05 g of the Ti3C2T x quantum dots (MQD) obtained in Step 1. After complete dissolution, transfer the solution to a 50 mL autoclave and heat at 180 °C for 24 h. After cooling to room temperature, centrifuge the solution, collect the precipitate, wash it three times with absolute ethanol and deionized water respectively, and freeze-dry to obtain in-situ grown Ti3C2T x quantum dots@SnS2 (MQD@SnS2);

[0056] Figure 2 For the Ti3C2T x electron microscopy image, Mapping image and characterization image of S vacancies of the quantum dots@SnS2 prepared in Example 1. Among them, (A) is the electron microscopy image and Mapping image, and (B) is the characterization image of S vacancies. Figure 2 Illustrate the successful preparation of SnS2 and Ti3C2T x quantum dots@SnS2.

[0057] Step 3: Prepare an electrochemiluminescence sensor based on Ti3C2T x quantum dots@SnS2:

[0058] First, in a 0.5 mM chloroauric acid solution, use ITO (size: 1 cm × 1 cm) as the working electrode, a platinum wire as the counter electrode, and Ag / AgCl as the reference electrode. Perform electrodeposition for 100 s at a constant voltage of -0.245 V to obtain AuNPs / ITO. Add SH-cDNA (8 μL, 1 μM) to the surface of the AuNPs / ITO electrode and incubate at 37 °C for 2 h. SH-cDNA serves as a capture probe for subsequent binding to target molecules or aptamers. Then, add 5 μL of 6-mercapto-1-hexanol (MCH) (0.1 mM) solution and incubate at 4 °C for 2 h to block non-specific binding sites, obtaining cDNA / AuNP / ITO. At the same time, co-incubate the SH-modified DNA probe (3 μM, 500 μL) with MQD@SnS2 (500 μL) at room temperature for 3 h to obtain SH-Apt-MQD@SnS2 driven by the affinity of thiol groups for metal atoms exposed on the surface. Subsequently, drop 10 μL of SH-Apt-MQD@SnS2 on the electrode surface and incubate at 37 °C for 1 h. After incubation, wash the electrode with phosphate buffer to remove unbound substances to form an electrochemiluminescence sensor based on Ti3C2T x quantum dots@SnS2, denoted as MQD@SnS2-Apt / cDNA / AuNP / ITO.

[0059] Figure 3 For the aforementioned Ti3C2T-basedx Schematic diagram of the preparation process of the electrochemiluminescence sensor based on quantum dots@SnS2

[0060] The Ti3C2T prepared in this example x The electrochemiluminescence sensor based on quantum dots@SnS2 was subjected to electrochemiluminescence tests in a phosphate buffer solution containing 150 mM potassium persulfate. Among them, the scanning voltage was 0 to -1.5 V, the scanning rate was 0.15 V / s, and the photomultiplier tube was 800 V. The results are as Figure 4 shown

[0061] Figure 4 For the feasibility analysis results of the electrochemiluminescence sensor based on Ti3C2T prepared in Example 1 x Among them, (A) is the CV diagram, (B) is the EIS diagram, and (C) is the ECL signal detection diagram at different AFB1 concentrations. In Figure 4 (A) and (B), a represents ITO; b represents AuNP / ITO; c represents cDNA / AuNP / ITO; d represents MQD@SnS2-Apt / cDNA / AuNP / ITO

[0062] It can be seen from Figure 4 that the impedance of bare ITO is 30 Ω. The impedance of Au / ITO is about 16 Ω, which is due to the strong conductivity of AuNP. When SH-cDNA is successfully connected to the modified electrode through Au-S bonds, the impedance increases to 20 Ω due to the presence of cDNA. When Apt-MQD@SnS2 subsequently attaches to the complementary bases of SH-DNA on the electrode, the impedance drops to about 10 Ω. In the cyclic voltammogram (CV) ( Figure 4 (A) in), compared with the bare ITO electrode, the current increases after depositing gold. After binding cDNA through Au-S bonds, the current decreases, but the current increases slightly again after the attachment of Apt-MQD@SnS2, confirming the conductive properties of the Apt-MQD@SnS2 complex. The opposite trends observed in EIS and CV indicate the successful construction of the sensor ( Figure 4 (B) in). Further, the feasibility of the ECL sensor was detected using different concentrations of AFB1 (0, 0.1, 10 μg / kg). In Figure 4 (C), the ECL intensity gradually decreases with the increase in AFB1 concentration. This decrease is attributed to the specific binding of Apt-MQD@SnS2 to AFB1, resulting in the dissociation between complementary DNAs and the subsequent detachment of MQD@SnS2 from the electrode surface. These results clearly demonstrate the ability of the ECL sensor to monitor AFB1 and verify its potential for practical applications

[0063] Effect detection:

[0064] Detection of AFB1 concentration in dried fish samples:

[0065] (1) Establishment of AFB1 concentration prediction model:

[0066] Prepare AFB1 standard solutions with concentrations of 0.001 μg / kg, 0.01 μg / kg, 0.1 μg / kg, 1 μg / kg, 10 μg / kg, 20 μg / kg, 40 μg / kg, 60 μg / kg, 80 μg / kg, and 100 μg / kg. Respectively take 10 μL and add them to the electrochemiluminescence sensor based on Ti3C2T x Quantum dot @ SnS2. Incubate at 37 °C for 1 h. After completion, rinse with phosphate buffer and dry with nitrogen, and then measure the electrochemiluminescence intensity of the electrochemiluminescence sensor; perform linear fitting with the concentrations of different AFB1 standard solutions and the electrochemiluminescence intensity to establish a prediction model for AFB1 concentration detection.

[0067] Figure 5 (A) in is the electrochemiluminescence signal diagram of the sensor when detecting different concentrations of AFB1 and the established standard curve.

[0068] From Figure 5 (A) in it can be seen that as the concentration of AFB1 increases, the electrochemiluminescence signal continuously increases; through linear fitting, the standard curve for AFB1 detection is obtained as I ECL =-1158.3logC AFB1 +5341.8, the correlation coefficient R 2 =0.9923, the detection limit LOD is 1.24×10 -4 μg / kg, and the linear range is 0.001 - 100 μg / kg.

[0069] (2) Anti-interference experiment of AFB1:

[0070] To demonstrate the selectivity of the sensor described in the present invention for AFB1 detection, ochratoxin A (OTA), T-2 toxin (T-2), deoxynivalenol (DON), and zearalenone (ZEN) (all purchased from Tanmo Quality Inspection Technology Co., Ltd.) are selected as interference components for investigation. At the same time, a blank control group (Blank) and a mixed group of AFB1, ochratoxin A (OTA), T-2 toxin (T-2), deoxynivalenol (DON), and zearalenone (ZEN) (Mixture) are set up. The results are as shown in Figure 5 (B) in.

[0071] Figure 5 (B) in is the result of the anti-interference experiment of AFB1.

[0072] As can be seen from (B) in Figure 5 it can be seen that only when interacting with AFB1, the ECL signal of the system will change significantly. The ECL changes caused by OTA, T-2, DON, and ZEN are very small. The above results indicate that the sensor described in the present invention has good selectivity for the detection of AFB1.

[0073] (3) Detection of AFB1 concentration in dried fish samples:

[0074] Prepare 3 dried fish samples of 2 g each, and add AFB1 standard solutions with different concentrations respectively to ensure the presence of AFB1 at different concentrations (5 μg / kg, 10 μg / kg, 20 μg / kg) in the dried fish. Subsequently, mix the 3 dried fish samples with 10 mL of extraction solvent (methanol / water, 7:3, v / v) and incubate for 15 min, then centrifuge at a speed of 8000 r / min for 15 min. Finally, take 10 μL of the supernatant obtained in the above step to the surface of the electrochemiluminescence sensor based on Ti3C2T x Quantum dot @ SnS2 for incubation for 1 h, then measure the electrochemiluminescence intensity signal, substitute it into the standard curve obtained in step (1), and calculate the average concentrations of AFB1 contained in the 3 dried fish samples to be 4.8 μg / kg, 9.73 μg / kg, and 19.13 μg / kg respectively; compare with the concentrations of AFB1 measured by the national standard method - liquid chromatography tandem mass spectrometry for the 3 samples, and the results are: 4.62 μg / kg, 9.55 μg / kg, 18.9 μg / kg; it can be found by comparison that the method of the present invention has high precision (Table 1).

[0075] Table 1 Comparison of the detection of AFB1 in dried fish by the ECL sensor and liquid chromatography tandem mass spectrometry

[0076]

[0077] In the table, SD a : Standard deviation, n = 3;

[0078] RSD b : Relative standard deviation;

[0079] P c : p > 0.05 indicates no significant difference.

[0080] In this specification, each embodiment is described in a progressive manner. The key points of each embodiment are the differences from other embodiments. For the same and similar parts among the embodiments, reference can be made to each other.

[0081] The foregoing description of the disclosed embodiments enables those skilled in the art to implement or use the present invention. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein can be implemented in other embodiments without departing from the spirit or scope of the present invention. Thus, the present invention is not intended to be limited to the embodiments shown herein but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A Ti3C2T x The preparation method of quantum dots @SnS2 is characterized in that: The steps include: Ti3C2T x The quantum dots, sulfur source, tin source and solvent are mixed and heated to obtain the precipitate, which is the Ti3C2T x Quantum dots@SnS2.

2. The preparation method according to claim 1, characterized in that: The Ti3C2T x The preparation steps of quantum dots include: x The solution was mixed with tetramethylammonium hydroxide solution and reacted, and the precipitate was centrifuged and mixed with water and treated at 0-5°C for 1-3h. The supernatant was adjusted to pH 8-10 and heated to 100-150°C for 4-8h to obtain Ti3C2T x Quantum dots.

3. The preparation method according to claim 2, characterized in that: The Ti3C2T x The steps of preparing the solution include: x Add to a mixed solution of hydrochloric acid and lithium fluoride and react at 30-50°C for 18-30h to obtain Ti3C2T x Solution; The usage ratio of the hydrochloric acid, lithium fluoride, Ti3AlC2 and tetramethylammonium hydroxide solution is 10-30 mL: 0.8-3 g: 0.5-2 g: 30-60 mL; and / or the mass fraction of the tetramethylammonium hydroxide solution is 25%.

4. The preparation method according to claim 1, characterized in that: The sulfur source includes thioacetamide; and / or, the tin source includes tin chloride; and / or, the solvent includes isopropanol and / or ethanol; and / or, the sulfur source, tin source, solvent and Ti3C2T x The dosage ratio of quantum dots is 0.15-0.4g: 0.1-0.35g: 8-25mL: 0.05-0.2g; and / or, the temperature of the heating treatment is 150-180°C, and the time is 18-24h.

5. Ti3C2T prepared by the preparation method according to any one of claims 1 to 4 x Quantum dots@SnS2.

6. Ti3C2T as claimed in claim 5 x Application of quantum dots@SnS2 in the preparation of electrochemiluminescence sensors.

7. A Ti3C2T based x The electrochemiluminescent sensor of quantum dots@SnS2 is characterized by: The electrochemiluminescent sensor utilizes the Ti3C2T x Quantum dots@SnS2 were prepared.

8. The Ti3C2T based method according to claim 7 x The preparation method of quantum dot@SnS2 electrochemiluminescence sensor is characterized in that: The steps include: Using ITO as a working electrode, AuNPs / ITO was obtained by electro-deposition in a tetrachloroauric acid solution. AuNPs / ITO was incubated in SH-cDNA, 6-mercapto-1-hexanol, and SH-Apt-MQD@SnS2 in sequence to obtain the Ti3C2T x Electrochemiluminescence sensor of quantum dots@SnS2; The SH-Apt-MQD@SnS2 is a SH-modified DNA probe and the Ti3C2T x Quantum dots@SnS2 were prepared.

9. The preparation method according to claim 8, characterized in that: The concentration of the tetrachloroauric acid solution is 0.1 to 0.5 mM; and / or, the concentration of the SH-cDNA is 0.2 to 1 μM; and / or, the concentration of the 6-mercapto-1-hexanol is 0.05 to 0.1 mM; and / or, the concentration of the aptamer in the SH-Apt-MQD@SnS2 is 1 to 3 μM; and / or, the conditions for the electrodeposition are: -0.1 to 0.245 V, 10 to 100 s; and / or, the conditions for incubation in the SH-cDNA are: 25 to 37 ° C, 1 to 2 h; and / or, the conditions for incubation in the 6-mercapto-1-hexanol are: 4 to 25 ° C, 2 to 3 h; and / or, the conditions for incubation in the SH-Apt-MQD@SnS2 are: 25 to 37 ° C, 3 to 5 h; And / or, the preparation steps of the SH-Apt-MQD@SnS2 include: x Quantum dots @SnS2 and SH-modified DNA probe were incubated together for 3 h to obtain SH-Apt-MQD@SnS2; the concentration of the SH-modified DNA probe was 3 μM; the Ti3C2T x The volume ratio of QDs@SnS2 and SH-modified DNA probes was 1:

1.

10. The Ti3C2T based method according to claim 7 x The application of quantum dot@SnS2 electrochemiluminescence sensor in food detection is characterized by: The food detection includes the detection of aflatoxin B1 in food.

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