Preparation method and application of a tripodal photoelectrochemical sensor based on water-stable perovskite material and circular DNA

Abstract

The invention discloses a preparation method and application of a tripod photoelectrochemical sensor based on water-stable perovskite material and circular DNA, and belongs to the application technical field of photoelectric materials. The method comprises the following steps: S1, preparing (BA)2PbI4-Pb(OH)2 perovskite nanomaterial; S2, preparing (BA)2PbI4-Pb(OH)2 photoelectrode; S3, preparing photoelectrochemical sensor: (1) taking template DNA and splint chain and adding them to Tris-HCl buffer, mixing and heating, adding T4 ligase to catalyze cyclization, then adding exonuclease I and exonuclease I buffer and exonuclease III and exonuclease III buffer, heating after incubation to obtain circular DNA, and then incubating acetamiprid aptamer with its recognition chain cDNA; (2) dropping amino-modified DNA onto the surface of the photoelectrode for incubation, and then dropping hairpin DNA for incubation. The (BA)2PbI4-Pb(OH)2 prepared by the present invention can realize the stability of perovskite in water and the effective conversion of light to electricity. The sensor prepared by using it as a photosensitive material has high sensitivity and good stability, and can realize the detection of acetamiprid.

Description

Technical Field

[0001] The present invention relates to the technical field of application of photoelectric materials, and in particular to a preparation method and application of a tripodal photoelectrochemical sensor based on water-phase stable perovskite material and circular DNA mediation. Background Art

[0002] Perovskite materials are considered to be one of the most promising optoelectronic materials of the next generation due to their advantages such as high light absorption coefficient, large carrier mobility and simple synthesis method. Their excellent performance in various fields such as solar cells, light-emitting diodes, photodetectors and other optoelectronic devices has attracted great attention. However, their poor stability under humid conditions has seriously hindered their application in practice.

[0003] Acetamiprid is a nicotinic insecticide that acts on nicotinic acetylcholine receptors in the synaptic sites of the insect nervous system and is currently widely used in pest control. However, the excessive use of acetamiprid has led to environmental and ecological damage, and studies have found that acetamiprid residues in agricultural products can seriously endanger human health. Therefore, there is an urgent need to explore new strategies for efficient and sensitive detection of acetamiprid.

[0004] In recent years, with the gradual maturity of detection technology, more and more methods have been used for pesticide residue detection, including high performance chromatography-mass spectrometry, thin layer chromatography, capillary electrophoresis-mass spectrometry and single molecule real-time sequencing. However, the above methods all have the disadvantages of high cost, complex operation, time-consuming and large-scale instrumentation. Therefore, it is very important to develop simple, fast, low-cost alternative methods with high sensitivity and high selectivity. Photoelectrochemical sensors have the advantages of low background signal, high sensitivity and fast detection speed, and have received widespread attention in pesticide detection. In view of the above problems, the present invention proposes a preparation method and application of a tripod photoelectrochemical sensor based on water-stable perovskite materials and circular DNA. Summary of the invention

[0005] The purpose of the present invention is to provide a preparation method and application of a tripodal photoelectrochemical sensor based on a water-phase stable perovskite material and circular DNA. The prepared (BA)2PbI4-Pb(OH)2 (butylamine lead iodide-lead hydroxide) can achieve the stability of the perovskite in water and the effective conversion of light to electricity. The sensor prepared using it as a photosensitive material has high sensitivity and good stability, and can realize the detection of acetamiprid.

[0006] To achieve the above object, the present invention provides a method for preparing a tripodal photoelectrochemical sensor based on a water-stable perovskite material and a cyclic DNA, comprising the following steps:

[0007] S1. Preparation of (BA)2PbI4-Pb(OH)2 perovskite nanomaterials;

[0008] S2, preparation of (BA)2PbI4-Pb(OH)2 photoelectrode;

[0009] S3, preparing photoelectrochemical sensor;

[0010] S3-1, take the template DNA and the splint chain and add them to Tris-HCl buffer, mix and heat, add T4 ligase to catalyze cyclization, then add exonuclease I and exonuclease I buffer and exonuclease III and exonuclease III buffer, incubate and heat to obtain circular DNA, and then incubate the acetamiprid aptamer with its recognition chain cDNA;

[0011] S3-2, drop the amino-modified DNA onto the surface of the photoelectrode for incubation, then drop bovine serum albumin, and finally drop hairpin DNA for incubation to obtain a photoelectrochemical sensor.

[0012] Preferably, the specific operation of step S3-1 is: take 1-3 μL template DNA and 1.5-4.5 μL splint chain and add them to 8.5 μL Tris-HCl buffer, heat at 95°C for 5 min after mixing, slowly reduce to 25°C and heat for 3 h, add 4-10 μL T4 ligase to catalyze cyclization at 16°C, then heat at 65°C for 10 min, add 2-6 μL nuclease I and 1-3 μL nuclease I buffer and 1-3 μL nuclease III and 1-3 μL nuclease III buffer to shear off excess DNA chain, incubate at 37°C for 1.5 h, and then heat at 80°C for 15 min to obtain circular DNA; incubate the acetamiprid aptamer and its recognition chain cDNA at 95°C for 5 min and then cool naturally.

[0013] Preferably, the specific operation of step S3-2 is: drop 20 μL, 2 μM amino-modified DNA onto the electrode surface and incubate at 37°C for 2 hours, after the incubation, drop 20 μL, 1 wt% bovine serum albumin on the electrode surface to block non-specific binding sites for 40 minutes, then drop 20 μL, 2 μM hairpin DNA into the electrode, and incubate at 37°C for 2 hours to obtain a photoelectrochemical sensor.

[0014] Preferably, the specific operation of step S1 is: take 0.1-1g lead iodide, 1-5mL hydroiodic acid and 0.05-0.2mL n-butylamine, mix them, put them into a container containing 5-20mL volatile alkali solution, seal and stir, then wash with ultrapure water and dry, to obtain (BA)2PbI4-Pb(OH)2 nanomaterial.

[0015] Preferably, the volatile alkaline solution is one of ammonia water, n-butylamine, dimethylamine and diethylamine.

[0016] Preferably, the specific operations of step S2 are:

[0017] S2-1, ultrasonically cleaning the conductive glass with acetone, ethanol and ultrapure water in sequence, and then drying;

[0018] S2-2, prepare 25 μL of a nanomaterial suspension with a concentration of 5 to 10 mg / mL, drop it onto the conductive surface of the conductive glass, and dry it to obtain an electrode;

[0019] S2-3. Chitosan solution was dripped onto the electrode surface, and after drying, it was washed with sodium hydroxide and deionized water, and then glutaraldehyde solution was dripped, and finally, it was washed with deionized water to obtain a (BA)2PbI4-Pb(OH)2 photoelectrode.

[0020] Preferably, in step S2-3, the volume of the chitosan solution is 20 μL, and the concentration is 0.1 wt% to 0.3 wt%; the concentration of sodium hydroxide is 0.1 M; and the volume of the glutaraldehyde solution is 20 μL, and the concentration is 3 wt% to 6 wt%.

[0021] The photoelectrochemical sensor prepared by the preparation method is applied to the sensitive detection of acetamiprid.

[0022] Preferably, the application of the photoelectrochemical sensor in the sensitive detection of acetamiprid comprises the following specific steps:

[0023] (1) Add different concentrations of acetamiprid samples to the solution after incubation of the acetamiprid aptamer and its recognition chain cDNA, incubate at 37°C to release the cDNA, and then incubate the obtained solution with the circular DNA at room temperature for 30 minutes to obtain a DNA walker;

[0024] (2) The sensor electrode was then immersed in a mixed solution containing DNA walker, Klenow fragment, Klenow buffer, and deoxynucleotides and incubated in an oven at 37°C for 4 h;

[0025] (3) Under the irradiation of an excitation light source, the obtained sensor electrode is used as a working electrode, a three-electrode system is used to record the photocurrent signal, and a linear relationship curve between the photocurrent signal and the acetamiprid concentration is prepared to achieve sensitive detection of acetamiprid.

[0026] Therefore, the present invention adopts the above-mentioned preparation method and application of a tripodal photoelectrochemical sensor based on water-stable perovskite material and circular DNA, and the beneficial effects are as follows:

[0027] (1) The (BA)2PbI4-Pb(OH)2 prepared by the present invention can stably exist in a humid environment and has better stability and photoelectric conversion performance than ordinary perovskite materials;

[0028] (2) The present invention does not require harsh conditions such as high temperature, high pressure, and gas protection, and the preparation method is simple;

[0029] (3) The prepared photoelectrochemical sensor utilizes a self-priming polymerization reaction. After the addition of a DNA walker, the hairpin DNA on the electrode surface undergoes a polymerization reaction under the action of an enzyme, causing the hairpin DNA to detach from the electrode surface, reducing steric hindrance and thereby amplifying the signal (photocurrent), thereby achieving specific recognition and high-sensitivity detection of acetamiprid in the environment.

[0030] The technical solution of the present invention is further described in detail below through the accompanying drawings and embodiments. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] Figure 1 This is a SEM image of the (BA)2PbI4-Pb(OH)2 sample prepared in Example 1 of the present invention;

[0032] Figure 2 This is a SEM image of the (BA)2PbI4-Pb(OH)2 sample prepared in Example 2 of the present invention;

[0033] Figure 3 4 is a linear relationship curve between the photocurrent change value and the target concentration of the photoelectrochemical sensor of Example 4 of the present invention. DETAILED DESCRIPTION

[0034] The following detailed description of the embodiments of the present invention provided in the accompanying drawings is not intended to limit the scope of the invention claimed for protection, but merely represents selected embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0035] Example 1

[0036] The present embodiment provides a preparation method of a (BA)2PbI4-Pb(OH)2 perovskite nanomaterial, and the specific steps are as follows: 0.46g of lead iodide, 2mL of hydroiodic acid and 0.099mL of n-butylamine are mixed in a small wide-mouth bottle, and the mixture is put into a large wide-mouth bottle containing 10mL of aqueous ammonia. The wide-mouth bottle is sealed, stirred every other day, and sealed for 8 days, and then washed with ultrapure water several times, and dried in an oven at 60°C to obtain a (BA)2PbI4-Pb(OH)2 nanomaterial sample.

[0037] The SEM images of the prepared samples are shown in Figure 1 As shown by Figure 1 It can be seen that the synthesized (BA)2PbI4-Pb(OH)2 presents a rod-like structure.

[0038] Example 2

[0039] The present embodiment provides a preparation method of a (BA)2PbI4-Pb(OH)2 perovskite nanomaterial, and the specific steps are as follows: 0.46g of lead iodide, 2mL of hydroiodic acid and 0.099mL of n-butylamine are mixed in a small wide-mouth bottle, and the mixture is put into a large wide-mouth bottle containing 10mL of aqueous ammonia. The wide-mouth bottle is sealed, stirred every other day, and sealed for 10 days. Then, the sample is washed with ultrapure water several times, and dried in an oven at 60°C to obtain a (BA)2PbI4-Pb(OH)2 nanomaterial sample.

[0040] The SEM images of the prepared samples are shown in Figure 2 As shown by Figure 2 It can be seen that the prepared (BA)2PbI4-Pb(OH)2 presents a rod-like structure with a smooth surface.

[0041] Example 3

[0042] This example uses the (BA)2PbI4-Pb(OH)2 perovskite nanomaterial prepared in Example 2 as a base material to prepare a tripodal photoelectrochemical sensor based on a water-stable perovskite material and circular DNA, specifically comprising the following steps:

[0043] (1) The FTO conductive glass was ultrasonically cleaned with acetone, ethanol and ultrapure water in sequence, and then dried in an oven.

[0044] (2) Prepare 25 μL of a 5 mg / mL sample suspension, drop it onto the conductive surface of the FTO conductive glass, and dry it in an oven to obtain a (BA)2PbI4-Pb(OH)2 electrode.

[0045] (3) Add 20 μL of chitosan solution (0.1 wt%) to the electrode surface, and then place it in a 60°C oven to dry. After drying, use 0.1 M NaOH and deionized water to wash it. Then, add 20 μL of glutaraldehyde solution (5 wt%) to the electrode surface and keep it at room temperature for 60 minutes. After washing, use deionized water to obtain a photoelectrode.

[0046] (4) 1 μL template DNA and 1.5 μL splint were added to 8.5 μL Tris-HCl buffer, mixed and heated at 95°C for 5 min, slowly lowered to 25°C and heated for 3 h, then 4 μL T4 ligase was added to catalyze cyclization at 16°C overnight, then heated at 65°C for 10 min, then 2 μL exonuclease I (EXO I) and 1 μL EXO I buffer and 1 μL exonuclease III (EXO III) and 1 μL EXO III buffer were added to cut off the excess DNA chain, incubated at 37°C for 1.5 h, and heated at 80°C for 15 min to obtain circular DNA. The acetamiprid aptamer and its recognition chain cDNA were incubated at 95°C for 5 min and cooled naturally.

[0047] (5) 20 μL of amino-modified DNA (2 μM) was dropped onto the FTO surface and incubated at 37°C for 2 h. After the incubation, 20 μL of bovine serum albumin (1 wt%) was added to the electrode surface to block nonspecific binding sites for 40 min. Then, 20 μL of hairpin DNA (2 μM) was dropped into the electrode and incubated at 37°C for 2 h to obtain a photoelectrochemical sensor.

[0048] Example 4

[0049] In this example, the photoelectrochemical sensor prepared in Example 3 is used for sensitive determination of acetamiprid, and the specific steps are as follows:

[0050] (1) After the acetamiprid aptamer and its recognition chain cDNA were incubated, acetamiprid samples of different concentrations were added and incubated at 37°C to release the cDNA. The resulting solution was then incubated with the circular DNA at room temperature for 30 minutes to obtain a DNA walker.

[0051] (2) The sensor electrode was immersed in a mixed solution containing DNA walker, Klenow fragment (KF enzyme), Klenow buffer (10*Klenow Buffer), and deoxynucleotide (dNTP), and incubated in a 37°C oven for 4 h to amplify the signal using a self-priming polymerization reaction. After each incubation, the electrode was rinsed with PBS buffer.

[0052] (3) Under the irradiation of an excitation light source, the obtained sensor electrode is used as a working electrode, a three-electrode system is used to record the photocurrent signal, and a linear relationship curve between the photocurrent signal and the acetamiprid concentration is prepared to achieve sensitive detection of acetamiprid.

[0053] The photocurrent detection results are as follows Figure 3 As shown in the figure, the photocurrent change value is plotted against the acetamiprid concentration. Figure 3It can be seen that the sensor shows a good linear relationship in the concentration range of 0.1-1000nM, indicating that the sensor can achieve quantitative detection of acetamiprid within a certain range.

[0054] Finally, it should be noted that the above embodiments are only used to illustrate the technical solution of the present invention rather than to limit it. Although the present invention has been described in detail with reference to the preferred embodiments, those skilled in the art should understand that they can still modify or replace the technical solution of the present invention with equivalents, and these modifications or equivalent replacements cannot cause the modified technical solution to deviate from the spirit and scope of the technical solution of the present invention.

Claims

1. An application of a water-stable perovskite material and a circular DNA-mediated tripod photoelectrochemical sensor in the sensitive detection of acetamiprid, characterized in that: The preparation method of the photoelectrochemical sensor comprises the following steps: S1. Preparation of (BA)2PbI4-Pb(OH)2 perovskite nanomaterials; S2, preparation of (BA)2PbI4-Pb(OH)2 photoelectrode; S3, preparing photoelectrochemical sensor; S3-1, take the template DNA and the splint chain and add them to Tris-HCl buffer, mix and heat, add T4 ligase to catalyze cyclization, then add exonuclease I and exonuclease I buffer and exonuclease III and exonuclease III buffer, incubate and heat to obtain circular DNA, and then incubate the acetamiprid aptamer with its recognition chain cDNA; S3-2, dropping the amino-modified DNA onto the surface of the photoelectrode for incubation, then dropping bovine serum albumin, and finally dropping the hairpin DNA for incubation to obtain a photoelectrochemical sensor; The application of photoelectrochemical sensors includes the following steps: (1) Add different concentrations of acetamiprid samples to the solution after incubation of acetamiprid aptamer and its recognition chain cDNA, incubate at 37°C to release cDNA, and then incubate the obtained solution with circular DNA at room temperature for 30 minutes to obtain a DNA walker; (2) The photoelectrochemical sensor was then immersed in a mixed solution containing DNA walker, Klenow fragment, Klenow buffer, and deoxynucleotides and incubated in an oven at 37°C for 4 h; (3) Under the irradiation of an excitation light source, the obtained photoelectrochemical sensor is used as the working electrode, and a three-electrode system is adopted to record the photocurrent signal. A linear relationship curve between the photocurrent signal and the concentration of acetamiprid is prepared to achieve sensitive detection of acetamiprid.

2. The use of a water-stable perovskite material and circular DNA-mediated tripodal photoelectrochemical sensor in the sensitive detection of acetamiprid according to claim 1, characterized in that: The specific operation of step S3-1 is as follows: 1-3 μL template DNA and 1.5-4.5 μL splint chain are added to 8.5 μL Tris-HCl buffer, mixed and heated at 95°C for 5 min, slowly reduced to 25°C and heated for 3 h, 4-10 μL T4 ligase is added to catalyze cyclization at 16°C, and then heated at 65°C for 10 min, 2-6 μL exonuclease I and 1-3 μL exonuclease I buffer and 1-3 μL exonuclease III and 1-3 μL exonuclease III buffer are added to cut off excess DNA chain, incubated at 37°C for 1.5 h, and then heated at 80°C for 15 min to obtain circular DNA; the acetamiprid aptamer and its recognition chain cDNA are incubated at 95°C for 5 min and then naturally cooled.

3. The use of a water-stable perovskite material and circular DNA-mediated tripodal photoelectrochemical sensor in the sensitive detection of acetamiprid according to claim 1, characterized in that: The specific operation of step S3-2 is: dripping 20 μL, 2 μM amino-modified DNA onto the electrode surface and incubating at 37°C for 2 hours. After the incubation, dripping 20 μL, 1 wt% bovine serum albumin onto the electrode surface to block non-specific binding sites for 40 minutes. Then dripping 20 μL, 2 μM hairpin DNA into the electrode and incubating at 37°C for 2 hours to obtain a photoelectrochemical sensor.

4. The use of a water-stable perovskite material and circular DNA-mediated tripod photoelectrochemical sensor in the sensitive detection of acetamiprid according to claim 1, characterized in that: The specific operation of step S1 is: take 0.1-1g lead iodide, 1-5mL hydroiodic acid and 0.05-0.2mL n-butylamine, mix them, put them into a container containing 5-20mL volatile alkali solution, seal and stir, then wash with ultrapure water and dry, to obtain (BA)2PbI4-Pb(OH)2 nanomaterial.

5. The use of a water-stable perovskite material and circular DNA-mediated tripodal photoelectrochemical sensor in the sensitive detection of acetamiprid according to claim 4, characterized in that: The volatile alkali solution is one of ammonia water, n-butylamine, dimethylamine and diethylamine.

6. The use of a water-stable perovskite material and circular DNA-mediated tripodal photoelectrochemical sensor in the sensitive detection of acetamiprid according to claim 1, characterized in that: The specific steps of step S2 are: S2-1, ultrasonically cleaning the conductive glass with acetone, ethanol and ultrapure water in sequence, and then drying; S2-2, prepare 25 μL of nanomaterial suspension with a concentration of 5-10 mg / mL, drop it onto the conductive surface of the conductive glass, and dry it to obtain an electrode; S2-3. Chitosan solution was dripped onto the electrode surface, and after drying, it was washed with sodium hydroxide and deionized water, and then glutaraldehyde solution was dripped, and finally, it was washed with deionized water to obtain a (BA)2PbI4-Pb(OH)2 photoelectrode.

7. The use of a water-stable perovskite material and circular DNA-mediated tripodal photoelectrochemical sensor in the sensitive detection of acetamiprid according to claim 6, characterized in that: In step S2-3, the volume of the chitosan solution is 20 μL, and the concentration is 0.1 wt% to 0.3 wt%; the concentration of sodium hydroxide is 0.1 M; the volume of the glutaraldehyde solution is 20 μL, and the concentration is 3 wt% to 6 wt%.

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