Preparation method and application of beta-Bi2O3 / Bi2S3 nano-enzyme catalyst
By preparing β-Bi2O3/Bi2S3 nanozyme catalysts and using Bi2O3 and Bi2S3 to form a heterojunction, the activity of the nanozyme was improved, the problem of low activity of bismuth sulfide nanozyme was solved, and efficient detection and degradation of tetracycline was achieved, ensuring food safety and public health.
Patent Information
- Application Number
- CN202511212738.9
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-08-28
- Publication Date
- 2025-10-21
AI Technical Summary
Existing bismuth sulfide nanozymes have low activity and are difficult to efficiently detect and degrade tetracycline, resulting in serious antibiotic contamination and affecting food safety and public health.
The β-Bi2O3/Bi2S3 nanozyme catalyst was prepared by a solvothermal method. Bi2O3 and Bi2S3 were composited to form a heterojunction, which enhanced electron transfer and active sites and improved catalytic activity. The specific recognition and highly sensitive detection of tetracycline were achieved by combining with the β-Bi2O3/Bi2S3/ssDNA aptamer probe.
The catalytic activity of the nanozyme was significantly improved, achieving efficient detection and degradation of tetracycline, with highly sensitive colorimetric detection and a degradation rate of up to 96%, and good stability and selectivity.
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Figure CN120815554A_ABST
Abstract
Description
Technical Field
[0001] The present invention relates to the technical field of nanoenzyme detection and antibiotic degradation, and in particular to a preparation method and application of a β-Bi2O3 / Bi2S3 nanoenzyme material. Background Art
[0002] While technological advancements have driven the expansion of the antibiotic market, they have also exacerbated the problem of antibiotic overuse, leading to significantly increased antibiotic residue concentrations in aquatic environments and becoming a significant source of pollution. Tetracycline (TC), for example, is widely present in water bodies due to its high water solubility (>1.3 g / L) and chemical stability (concentrations reaching μg / L). Furthermore, TC penetrates the food chain through multiple pathways: in aquaculture, TC is widely added to livestock and aquatic feeds as a growth promoter, resulting in excessive residues in animal-derived foods such as meat, eggs, and milk. In agricultural production, TC-containing wastewater irrigation leads to the absorption and accumulation of antibiotics in crops. In food processing, contaminated water used for cleaning or processing, coupled with inadequate supervision of withdrawal periods in aquaculture, further exacerbates the risk of antibiotic residues. TC poses a significant dose-accumulative risk to human health. High doses can cause liver failure and even death. Long-term low-dose exposure can damage liver and kidney function, induce liver cancer and cirrhosis, and cause carcinogenic, teratogenic, and mutagenic effects. Even trace amounts of TC residue can disrupt intestinal microbial homeostasis and accelerate the spread of drug-resistant bacteria. In addition, TC is resistant to high temperatures (cooking degradation rate <15%) and can withstand processing technologies such as irradiation and pasteurization, and TC still persists in food.
[0003] Bismuth sulfide (Bi2S3) is a narrow-bandgap semiconductor material, but the low activity of single Bi2S3 nanozymes limits their applications. Therefore, the development of a highly efficient technology for the detection and degradation of TC is urgently needed. This technology has significant research value and practical significance for disrupting the pollution chain, safeguarding food safety, and protecting public health. Summary of the Invention
[0004] In order to solve the problems of low nanozyme activity and tetracycline contamination, the purpose of the present invention is to provide a method for preparing β-Bi2O3 / Bi2S3 nanozyme catalyst. By compounding Bi2O3 and Bi2S3, the catalytic activity of β-Bi2O3 / Bi2S3 nanozyme is significantly improved, and it can efficiently catalyze the decomposition of strong oxidizing substances to produce reactive oxygen species (ROS), thereby realizing the detection and degradation of tetracycline.
[0005] The preparation method of the β-Bi2O3 / Bi2S3 nanozyme catalyst of the present invention comprises the following steps: (1) Dissolving bismuth nitrate pentahydrate in acetic acid to obtain a bismuth nitrate pentahydrate acetic acid solution, adding anhydrous ethanol to the bismuth nitrate pentahydrate acetic acid solution to obtain a mixed solution, adding tetraethyl orthosilicate (TEOS) to the mixed solution, stirring evenly, heating to react, and after the reaction is completed, centrifuging, washing, and drying to obtain a precursor material.
[0006] (2) Calcination of the precursor material to obtain β-Bi2O3.
[0007] (3) β-Bi2O3 and polyvinylpyrrolidone (PVP) were added to water and stirred evenly. Then, an aqueous solution of thioacetamide was added and heated for reaction. After the reaction was completed, the reaction was centrifuged, washed, and dried to obtain β-Bi2O3 / Bi2S3 nanozyme, in which the sulfur content accounted for approximately 0.3%~5% of the β-Bi2O3 / Bi2S3 nanozyme.
[0008] Preferably, the concentration of the bismuth nitrate pentahydrate acetic acid solution in step (1) of the present invention is 0.2-0.6 mol / L.
[0009] Preferably, the volume ratio of acetic acid to anhydrous ethanol in step (1) of the present invention is 1:3-7.
[0010] Preferably, the molar ratio of bismuth nitrate pentahydrate to tetraethyl orthosilicate in step (1) of the present invention is 4:1-3.
[0011] Preferably, the heating reaction conditions in step (1) of the present invention are: heating the reaction at 120°C-180°C for 32-48 hours.
[0012] Preferably, the calcination conditions in step (2) of the present invention are: calcination at 350°C-450°C for 2-6h.
[0013] Preferably, the mass ratio of β-Bi2O3 to polyvinyl pyrrolidone in step (3) of the present invention is 1-1.2:1.
[0014] Preferably, the concentration of the β-Bi2O3 suspension in step (3) of the present invention is 1-15 g / L.
[0015] Preferably, the concentration of the thioacetamide aqueous solution in step (3) of the present invention is 1%-10%.
[0016] Preferably, the volume ratio of the β-Bi2O3 suspension to the thioacetamide aqueous solution in step (3) of the present invention is 1:1-2.
[0017] Preferably, the heating reaction conditions in step (3) of the present invention are: reaction at 80-180°C for 2-8h.
[0018] Another object of the present invention is to provide the use of β-Bi2O3 / Bi2S3 nanozyme catalyst in the degradation of tetracycline.
[0019] Another object of the present invention is to provide an application of β-Bi2O3 / Bi2S3 nanozyme catalyst in the detection of tetracycline, specifically, preparing the β-Bi2O3 / Bi2S3 nanozyme catalyst into a β-Bi2O3 / Bi2S3 / ssDNA aptamer probe for detecting tetracycline.
[0020] The preparation of the β-Bi2O3 / Bi2S3 / ssDNA aptamer probe of the present invention includes: adding TC-ssDNA to a buffer solution and then incubating; adding a β-Bi2O3 / Bi2S3 nanozyme catalyst after the incubation is completed, and continuing to incubate; and washing with a Tris-HCl solution after the incubation is completed to obtain a β-Bi2O3 / Bi2S3 / ssDNA aptamer probe.
[0021] Preferably, the buffer solution of the present invention is composed of a mixture of tris(2-carboxyethyl)phosphine hydrochloride solution and Tris-HCl solution; the concentration of the tris(2-carboxyethyl)phosphine hydrochloride solution is 10.0 mg / mL; the concentration of the Tris-HCl solution is 10.0 mmol / L, and the pH is 7.4; the volume ratio of the tris(2-carboxyethyl)phosphine hydrochloride solution to the Tris-HCl solution in the buffer solution is 0.2-1.5:0.5-2.0.
[0022] Preferably, the concentration of TC-ssDNA in the present invention is 40.0-160.0 nmol / L.
[0023] Preferably, the volume ratio of TC-ssDNA to buffer of the present invention is 0.05-0.2:2.5-3.0.
[0024] Mechanism of the invention: The present invention adopts a solvothermal method to prepare a β-Bi2O3 / Bi2S3 nanozyme, and significantly improves the activity of the nanozyme through the synergistic catalytic effect of the two matrix materials in multiple dimensions of energy band matching, electron transfer enhancement, and active site optimization. Specifically, β-Bi2O3 / Bi2S3 has a narrower band gap (~2.4 eV), while the band gap of Bi2S3 is even narrower (~1.3 eV). After the two form a heterojunction, the band structures match each other, and β-Bi2O3 and Bi2S3 form close contact at the interface to construct rich active sites. The sulfur vacancies of Bi2S3 can serve as electron capture centers to promote the generation of free radicals (such as •OH, •O2⁻), while β-Bi2O3 provides oxidation active sites. These sites enhance the substrate adsorption and activation ability through synergistic action. The two synergistically improve the catalytic reaction rate, produce more reactive oxygen, and significantly improve the activity of the nanozyme.
[0025] The aptamer described in the present invention can bind to peroxidase to specifically recognize TC. The modified aptamer probe has a high affinity with TC. After the aptamer binds to TC, it will cause changes in the activity of the nanozyme in the solution, thereby affecting the efficiency of the nanozyme-catalyzed substrate reaction, thereby realizing rapid and sensitive detection of TC.
[0026] The technical solution provided by the present invention can have the following beneficial effects: (1) The present invention prepared β-Bi2O3 / Bi2S3 nanozyme catalyst by solvothermal method. Bi ions served as the common metal source of β-Bi2O3 and Bi2S3 materials, synergistically catalyzing the two matrix materials to produce more active oxygen, with excellent peroxidase-like activity, significantly improving the catalytic performance.
[0027] (2) The β-Bi2O3 / Bi2S3 nanozyme catalyst prepared by the present invention has the function of efficiently detecting tetracycline. Based on the β-Bi2O3 / Bi2S3 / ssDNA aptamer probe, it can achieve specific recognition of TC and highly sensitive colorimetric detection, with low detection limit, wide linear range, excellent selectivity and anti-interference properties. On the other hand, the degradation rate of TC by the β-Bi2O3 / Bi2S3 composite nanozyme is as high as over 96%, showing excellent degradation ability and stability.
[0028] (3) The β-Bi2O3 / Bi2S3 nanozyme catalyst prepared by the present invention fully utilizes the advantages of β-Bi2O3's large specific surface area and abundant active sites. Combined with the precise control of process parameters, it can meet the needs of practical applications and has great application value in the detection and degradation of tetracycline.
[0029] (4) The free radicals generated by the catalytic oxidation of the substrate by the β-Bi2O3 / Bi2S3 nanozyme prepared in the present invention have strong oxidizing properties and can destroy its structure to effectively degrade TC. The present invention provides an integrated solution for the rapid detection and synchronous degradation of tetracycline pollutants, which has important application value in ensuring food safety and public health. BRIEF DESCRIPTION OF THE DRAWINGS
[0030] Figure 1 This is a scanning electron microscope image of the β-Bi2O3 / Bi2S3 nanozyme prepared in Example 1 of the present invention.
[0031] Figure 2 This is the XRD spectrum of the β-Bi2O3 / Bi2S3 nanozyme prepared in Example 1 of the present invention.
[0032] Figure 3 This is a standard curve diagram of TC detection using the β-Bi2O3 / Bi2S3 / ssDNA aptamer probe prepared in Example 1 of the present invention.
[0033] Figure 4 This is a diagram showing the effect of TC degradation by the β-Bi2O3 / Bi2S3 nanozyme prepared in Example 1 of the present invention. DETAILED DESCRIPTION
[0034] The present invention is further described in detail below with reference to the accompanying drawings and specific embodiments, but the protection scope of the present invention is not limited to the contents described above.
[0035] The concentration of the tris(2-carboxyethyl)phosphine hydrochloride solution used in the examples and comparative examples of the present invention was 10.0 mmol / L; the concentration of the Tris-HCl solution was 10.0 mmol / L, and the pH was 7.4.
[0036] Example 1 The specific steps for preparing the β-Bi2O3 / Bi2S3 nanozyme catalyst and the corresponding β-Bi2O3 / Bi2S3 / ssDNA aptamer probe in this example are as follows: (1) 4.0 mmol of Bi(NO3)3·5H2O was dissolved in 10.0 mL of acetic acid and subjected to continuous ultrasonic treatment for 20 min. Subsequently, 70.0 mL of anhydrous ethanol was added and stirred continuously for 30 min. 3.0 mmol of TEOS was slowly added dropwise to the above mixture and stirred for 30 min. The resulting mixture was transferred to a polytetrafluoroethylene-lined stainless steel autoclave and reacted at 160°C for 48 h. After the reaction, the mixture was centrifuged, washed with ethanol and water, and vacuum dried at 60°C for 12 h to obtain a grayish-white compound precursor.
[0037] (2) The precursor was calcined at 400 °C (heating rate 5 °C / min) for 5 h to obtain light yellow β-Bi2O3.
[0038] (3) 91 mg of β-Bi2O3 was dispersed in 15.0 mL of ultrapure water, and 84 mg of PVP was added and stirred for 20 min. Subsequently, 22.5 mL of a 5% aqueous solution of thioacetamide was added dropwise, and stirring was continued for 30 min. The mixture was heated at 160 °C for 6 h. After the reaction, the mixture was centrifuged, washed with ultrapure water, and dried to obtain β-Bi2O3 / Bi2S3.
[0039] (4) 100 μL of 160 nmol / L TC-ssDNA was added to 6.0 mL of buffer (the buffer was a mixture of 0.55 mL of tris(2-carboxyethyl)phosphine hydrochloride solution and 5.45 mL of Tris-HCl solution), and then incubated at 37 °C for 1 h; then 1.0 mg of β-Bi2O3 / Bi2S3 was added, and the mixture was incubated for another 12 h and washed three times with Tris-HCl to obtain a β-Bi2O3 / Bi2S3 / ssDNA aptamer probe.
[0040] The sulfur content in the β-Bi2O3 / Bi2S3 nanozyme material prepared in this example is approximately 0.6%.
[0041] The β-Bi2O3 / Bi2S3 / ssDNA aptamer probe synthesized in this example has a significant response to 60.0 μg / L TC, a detection limit of 0.41 μg / L for TC, a detection range of 1.0-300.0 μg / L, and good stability, selectivity, and anti-interference properties. The synthesized β-Bi2O3 / Bi2S3 has excellent nanozyme activity, and the removal rate of TC is as high as over 96%.
[0042] like Figure 1 As shown, the β-Bi2O3 / Bi2S3 nanozyme prepared in this example presents a spherical aggregate morphology with a distinct porous and sheet-like stacking structure, which can provide abundant active sites. Figure 2 The existence of two phases (β-Bi2O3 and Bi2S3) in the β-Bi2O3 / Bi2S3 nanozyme of this example is proved, and the β-Bi2O3 / Bi2S3 nanozyme has good crystallinity and high purity.
[0043] The synthesized β-Bi2O3 / Bi2S3 / ssDNA aptamer probe of the present invention exhibits excellent performance in detecting tetracycline (TC) in the range of 0-180 μg / L, such as Figure 3 As shown, the absorbance and concentration showed a good linear relationship (y = 2.79 × 10 -3 x+0.16, R²=0.9978), which conforms to the Lambert-Beer law. The high linearity and sensitivity indicate that the β-Bi2O3 / Bi2S3 / ssDNA aptamer probe of the present invention is accurate and reliable, suitable for the rapid quantitative detection of TC in environmental and biological samples, and has the advantages of simple operation and low cost.
[0044] The degradation rate of TC degradation of β-Bi2O3 / Bi2S3 composite nanozyme material prepared in this example is as follows: Figure 4As shown in the figure, the initial concentrations (C0) of TC solution are 5.0 mg / L), 10.0 mg / L, and 20.0 mg / L, respectively. As time increases, the relative concentration ratio (C / C0) decreases, indicating that the nanozyme material can degrade TC, and in the degradation process, the longer the time, the better the degradation effect.
[0045] Example 2 The specific steps for preparing the β-Bi2O3 / Bi2S3 nanozyme catalyst and the corresponding β-Bi2O3 / Bi2S3 / ssDNA aptamer probe in this example are as follows: (1) 2.0 mmol of Bi(NO3)3·5H2O was dissolved in 10.0 mL of acetic acid and subjected to continuous ultrasonic treatment for 20 min. Subsequently, 50.0 mL of anhydrous ethanol was added and stirred continuously for 30 min. 0.5 mmol of TEOS was slowly added dropwise to the above mixture and stirred for 30 min. The resulting mixture was transferred to a polytetrafluoroethylene-lined stainless steel autoclave and reacted at 180°C for 32 h. After the reaction, the mixture was centrifuged, washed with ethanol and water, and vacuum dried at 60°C for 12 h to obtain a grayish-white compound precursor.
[0046] (2) The precursor was calcined at 350 °C (heating rate 5 °C / min) for 6 h to obtain light yellow β-Bi2O3.
[0047] (3) 194.0 mg of β-Bi2O3 was dispersed in 13.0 mL of ultrapure water, and 181.0 mg of PVP was added and stirred for 20 min. Subsequently, 15.5 mL of a 1% thioacetamide aqueous solution was added dropwise, and stirring was continued for 30 min. The mixture was heated at 80 °C for 8 h. After the reaction, the mixture was centrifuged, washed with ultrapure water, and dried to obtain β-Bi2O3 / Bi2S3.
[0048] (4) 100 μL of 60 nmol / L TC-ssDNA was added to 5.0 mL of buffer (the buffer was a mixture of 3.75 mL of tris(2-carboxyethyl)phosphine hydrochloride solution and 1.25 mL of Tris-HCl solution), and then incubated at 37 °C for 1 h; then 1.0 mg of β-Bi2O3 / Bi2S3 was added, and the mixture was incubated for another 12 h and washed three times with Tris-HCl to obtain a β-Bi2O3 / Bi2S3 / ssDNA aptamer probe.
[0049] The sulfur content in the β-Bi2O3 / Bi2S3 nanozyme material prepared in this example is about 0.3%. The catalytic activity and TC degradation effect of the β-Bi2O3 / Bi2S3 nanozyme prepared in this example are similar to those in Example 1. The detection effect of the synthesized β-Bi2O3 / Bi2S3 / ssDNA aptamer probe is similar to that in Example 1.
[0050] Example 3 The specific steps for preparing the β-Bi2O3 / Bi2S3 nanozyme catalyst and the corresponding β-Bi2O3 / Bi2S3 / ssDNA aptamer probe in this example are as follows: (1) 6.0 mmol of Bi(NO3)3·5H2O was dissolved in 10.0 mL of acetic acid and subjected to continuous ultrasonic treatment for 20 min. Subsequently, 30.0 mL of anhydrous ethanol was added and stirred continuously for 30 min. 3.0 mmol of TEOS was slowly added dropwise to the above mixture and stirred for 30 min. The resulting mixture was transferred to a polytetrafluoroethylene-lined stainless steel autoclave and reacted at 120°C for 40 h. After the reaction, the mixture was centrifuged, washed with ethanol and water, and vacuum dried at 60°C for 12 h to obtain a grayish-white compound precursor.
[0051] (2) The precursor was calcined at 450 °C (heating rate 5 °C / min) for 3 h to obtain light yellow β-Bi2O3.
[0052] (3) Disperse 29.0 mg of β-Bi2O3 in 15.0 mL of ultrapure water, add 27.0 mg of PVP, and continue stirring for 20 min. Subsequently, add 28.5 mL of a 10% aqueous thioacetamide solution dropwise, continue stirring for 30 min, and heat the mixture at 180°C for 2 h. After the reaction, centrifuge, wash with ultrapure water, and dry to obtain β-Bi2O3 / Bi2S3.
[0053] (4) 100 μL of TC-ssDNA with a concentration of 160 nmol / L was added to 1.25 mL of buffer (the buffer was a mixture of 0.54 mL of tris(2-carboxyethyl)phosphine hydrochloride solution and 1.71 mL of Tris-HCl solution), and then incubated at 37°C for 1 h; then 1.0 mg of β-Bi2O3 / Bi2S3 was added, and the mixture was incubated for another 12 h and washed three times with Tris-HCl to obtain a β-Bi2O3 / Bi2S3 / ssDNA aptamer probe.
[0054] The mass fraction of sulfur element in the β-Bi2O3 / Bi2S3 nanozyme material prepared in this example is 5%. The catalytic activity and TC degradation effect of the β-Bi2O3 / Bi2S3 nanozyme prepared in this example are similar to those in Example 1. The detection effect of the synthesized β-Bi2O3 / Bi2S3 / ssDNA aptamer probe is similar to that in Example 1.
[0055] Comparative Example 1 The specific steps for preparing the β-Bi2O3 / Bi2S3 nanozyme catalyst and the corresponding β-Bi2O3 / Bi2S3 / ssDNA aptamer probe in this comparative example are as follows: (1) 2.0 mmol of Bi(NO3)3·5H2O was dissolved in 10.0 mL of acetic acid and subjected to continuous ultrasonic treatment for 20 min. Subsequently, 70.0 mL of anhydrous ethanol was added and stirred continuously for 30 min. 0.5 mmol of TEOS was slowly added dropwise to the above mixture and stirred for 30 min. The resulting mixture was transferred to a polytetrafluoroethylene-lined stainless steel autoclave and reacted at 150°C for 48 h. After the reaction, the mixture was centrifuged and then washed with ethanol and water. It was vacuum dried at 60°C for 12 h to obtain a grayish-white compound precursor.
[0056] (2) The precursor was calcined at 350 °C (heating rate 5 °C / min) for 5 h to obtain light yellow β-Bi2O3.
[0057] (3) Disperse 194.0 mg of β-Bi2O3 in 15.0 mL of ultrapure water, add 186.0 mg of PVP, and continue stirring for 20 min. Then, add 20.0 mL of 5% thioacetamide solution dropwise, continue stirring for 30 min, and then heat at 160°C for 6 h. After the reaction, centrifuge, wash with ultrapure water, and dry to obtain β-Bi2O3 / Bi2S3.
[0058] (4) 100 μL of 100 nmol / L TC-ssDNA was added to 1 mL of buffer (the buffer was a mixture of 0.5 mL of tris(2-carboxyethyl)phosphine hydrochloride solution and 0.5 mL of Tris-HCl solution), and then incubated at 37°C for 1 h; then 1.0 mg of β-Bi2O3 / Bi2S3 was added, and the mixture was incubated for another 12 h and washed three times with Tris-HCl to obtain a β-Bi2O3 / Bi2S3 / ssDNA aptamer probe.
[0059] The sulfur content in the β-Bi2O3 / Bi2S3 nanozyme material prepared in Comparative Example 1 is about 0.2%. The β-Bi2O3 / Bi2S3 nanozyme material prepared in this comparative example is tested by colorimetric reaction. The nanozyme activity of the material is not as good as that of the material in Comparative Example 1, and the synthesized β-Bi2O3 / Bi2S3 / ssDNA aptamer probe has no obvious detection effect on TC.
[0060] Comparative Example 2 The specific steps for preparing the β-Bi2O3 / Bi2S3 nanozyme catalyst and the corresponding β-Bi2O3 / Bi2S3 / ssDNA aptamer probe in this comparative example are as follows: (1) 4.0 mmol of Bi(NO3)3·5H2O was dissolved in 10.0 mL of acetic acid and subjected to continuous ultrasonic treatment for 20 min. Subsequently, 70.0 mL of anhydrous ethanol was added and stirred continuously for 30 min. 3.0 mmol of TEOS was slowly added dropwise to the above mixture and stirred for 30 min. The resulting mixture was transferred to a polytetrafluoroethylene-lined stainless steel autoclave and reacted at 150°C for 48 h. After the reaction, the mixture was centrifuged, washed with ethanol and water, and vacuum dried at 60°C for 12 h to obtain a grayish-white compound precursor.
[0061] (2) The precursor was calcined at 400 °C (heating rate 5 °C / min) for 5 h to obtain light yellow β-Bi2O3.
[0062] (3) Disperse 124.0 mg of β-Bi2O3 in 15.0 mL of ultrapure water, add 181.0 mg of PVP and continue stirring for 20 min; add 20.0 mL of 10% thioacetamide solution dropwise, continue stirring for 30 min, and then heat at 160 °C for 6 h; after the reaction, centrifuge, wash with ultrapure water, and dry to obtain β-Bi2O3 / Bi2S3.
[0063] (4) 50 μL of 100 nmol / L TC-ssDNA was added to 1 mL of buffer (the buffer was a mixture of 0.5 mL of tris(2-carboxyethyl)phosphine hydrochloride solution and 0.5 mL of Tris-HCl solution), and then incubated at 37°C for 1 h; then 1.0 mg of β-Bi2O3 / Bi2S3 was added, and the mixture was incubated for another 12 h and washed three times with Tris-HCl to obtain a β-Bi2O3 / Bi2S3 / ssDNA aptamer probe.
[0064] The β-Bi2O3 / Bi2S3 / ssDNA aptamer probe prepared in this comparative example responded to 60.0 μg / L TC, but the response value was small.
[0065] In summary, the β-Bi2O3 / Bi2S3 composite nanozyme prepared in the present invention exhibits excellent degradation ability and stability for TC; the β-Bi2O3 / Bi2S3 / ssDNA aptamer probe synthesized in the present invention can specifically recognize TC, and β-Bi2O3 / Bi2S3 / ssDNA can directly capture TC and adsorb it on the active sites on the surface of the material to reduce the activity of its nanozyme, thereby realizing quantitative colorimetric detection of TC.
[0066] While various embodiments of the present invention have been described above, the foregoing description is intended to be illustrative, non-exhaustive, and not limited to the disclosed embodiments. Many modifications and variations will be apparent to those skilled in the art without departing from the scope and spirit of the described embodiments. The terminology used herein is selected to best explain the principles of the embodiments, their practical applications, or improvements to existing technologies, or to enable others skilled in the art to understand the embodiments disclosed herein.
Claims
1. A method for preparing a β-Bi2O3 / Bi2S3 nanozyme catalyst, characterized in that: The following steps are involved: (1) dissolving bismuth nitrate pentahydrate in acetic acid to obtain a bismuth nitrate pentahydrate acetic acid solution, adding anhydrous ethanol to the bismuth nitrate pentahydrate acetic acid solution to obtain a mixed solution, adding tetraethyl orthosilicate to the mixed solution, stirring uniformly, heating to react, centrifuging after the reaction is completed, washing, and drying to obtain a precursor material; (2) calcining the precursor material to obtain β-Bi2O3; (3) Dispersing β-Bi2O3 in water to obtain a β-Bi2O3 suspension, adding polyvinyl pyrrolidone to the β-Bi2O3 suspension, mixing evenly, then adding an aqueous solution of thioacetamide, heating for reaction, and after the reaction is completed, centrifuging, washing, and drying to obtain β-Bi2O3 / Bi2S3.
2. The method for preparing the β-Bi2O3 / Bi2S3 nanozyme catalyst according to claim 1, characterized in that: The concentration of the bismuth nitrate pentahydrate acetic acid solution in step (1) is 0.2-0.6 mol / L; the volume ratio of the bismuth nitrate pentahydrate acetic acid solution to anhydrous ethanol is 1:3-7; and the molar ratio of the bismuth nitrate pentahydrate to tetraethyl orthosilicate is 4:1-3.
3. The method for preparing the β-Bi2O3 / Bi2S3 nanozyme catalyst according to claim 1, characterized in that: The heating reaction conditions in step (1) are: heating the reaction at 120°C-180°C for 32-48 hours.
4. The method for preparing the β-Bi2O3 / Bi2S3 nanozyme catalyst according to claim 1, characterized in that: The calcination conditions in step (2) are: calcination at 350°C-450°C for 2-6 hours.
5. The method for preparing the β-Bi2O3 / Bi2S3 nanozyme catalyst according to claim 1, characterized in that: In step (3), the mass ratio of β-Bi2O3 to polyvinyl pyrrolidone is 1-1.2:1; the concentration of the β-Bi2O3 suspension is 1-15 g / L; the mass concentration of the thioacetamide aqueous solution is 1%-10%; the volume ratio of the β-Bi2O3 suspension to the thioacetamide aqueous solution is 1:1-2; and the heating reaction conditions are: heating the reaction at 80-180°C for 2-8 hours.
6. Use of the β-Bi2O3 / Bi2S3 nanozyme catalyst prepared by the method according to any one of claims 1 to 5 in the degradation of tetracycline.
7. Use of the β-Bi2O3 / Bi2S3 nanozyme catalyst prepared by the method according to any one of claims 1 to 5 in tetracycline detection, characterized in that: The β-Bi2O3 / Bi2S3 nanozyme catalyst was prepared into a β-Bi2O3 / Bi2S3 / ssDNA aptamer probe. The specific steps were as follows: TC-ssDNA was added to a buffer solution and then incubated; after the incubation, the β-Bi2O3 / Bi2S3 nanozyme catalyst was added and the incubation was continued; after the incubation, the β-Bi2O3 / Bi2S3 nanozyme catalyst was washed with a Tris-HCl solution to obtain a β-Bi2O3 / Bi2S3 / ssDNA aptamer probe. The β-Bi2O3 / Bi2S3 / ssDNA aptamer probe can be used for the detection of tetracycline.
8. The use of the β-Bi2O3 / Bi2S3 nanozyme catalyst in the detection of tetracycline according to claim 7, characterized in that: The buffer solution is composed of a mixture of a tris(2-carboxyethyl)phosphine hydrochloride solution and a Tris-HCl solution; the concentration of the tris(2-carboxyethyl)phosphine hydrochloride solution in the buffer solution is 10.0 mg / mL; the concentration of the Tris-HCl solution is 10.0 mmol / L, and the pH value is 7.4; and the volume ratio of the tris(2-carboxyethyl)phosphine hydrochloride solution to the Tris-HCl solution in the buffer solution is 0.2-1.5:0.5-2.
0.
9. The use of the β-Bi2O3 / Bi2S3 nanozyme catalyst in the detection of tetracycline according to claim 7, characterized in that: The concentration of the TC-ssDNA is 40.0-160.0 nmol / L, and the volume ratio of the TC-ssDNA to the buffer is 0.05-0.2:2.5-3.0.