A method for detecting and removing tetracycline antibiotics

Abstract

The application discloses a method for detecting and removing tetracycline antibiotics, comprising the following steps: preparing methoxy nickel hydroxide nanosheets (Ni(OH)OMe NNs); visually detecting tetracycline antibiotics; and removing tetracycline antibiotics. The Ni(OH)OMe NNs synthesized in the application have simple synthesis conditions, do not need complex and expensive instruments and equipment, and can be mass-produced. The detection condition of the application is mild, high in sensitivity and easy to operate, does not need any instruments and equipment and professional operators, the condition of tetracycline antibiotics in water can be preliminarily judged by visual method, and the detection requirement of different water environments can be met. The application realizes the removal of tetracycline antibiotics in water by chemical reaction of tetracycline antibiotics and Ni(OH)OMe NNs to generate cyan yellow precipitates, the removal rate of tetracycline antibiotics reaches more than 98% after stirring for 30 min, and the visual detection and efficient removal integration are realized.

Description

Technical Field

[0001] This invention relates to the field of chemical analysis and detection technology, specifically to a method for detecting and removing tetracycline antibiotics. Background Technology

[0002] Tetracycline antibiotics, such as tetracycline, oxytetracycline, doxycycline, and chlortetracycline, are widely used to treat bacterial infections in humans and animals due to their broad-spectrum antibacterial properties and low cost. These antibiotics mainly enter the aquatic environment through medical wastewater discharge, livestock and poultry farm wastewater leakage, aquaculture wastewater discharge, and pharmaceutical production wastewater discharge. Residual tetracycline antibiotics are considered a harmful pollutant in aquatic environments. Furthermore, antibiotics remain stable in water and are difficult to degrade, causing serious impacts on the ecological environment and human survival.

[0003] Currently, the detection of tetracycline antibiotics mainly relies on traditional analytical methods such as mass spectrometry, liquid chromatography, and liquid chromatography-mass spectrometry. However, these methods have limitations, such as requiring specialized personnel to operate complex instruments, cumbersome detection procedures, high testing costs, and long processing times, making them unsuitable for real-time online monitoring. In practical applications, it is difficult to detect antibiotic residues in water used in aquaculture and other industries in a timely manner, hindering effective treatment measures and limiting their widespread application in these fields. Furthermore, traditional detection methods only detect antibiotics but cannot remove them from the water.

[0004] Therefore, the field of tetracycline antibiotic detection urgently needs a simple-to-prepare detection material and a convenient detection method that can be operated on-site and whose results can be visually read. This method requires no instruments or professional personnel and can quickly detect and estimate the concentration range of tetracycline antibiotics in water. Summary of the Invention

[0005] To overcome the aforementioned defects and shortcomings in the existing technology, the present invention provides a method for the detection and removal of tetracycline antibiotics.

[0006] The first objective of this invention is to provide a method for preparing methoxy nickel hydroxide nanosheets.

[0007] A second objective of this invention is to provide methoxy nickel hydroxide nanosheets prepared by the aforementioned preparation method.

[0008] A third objective of this invention is to provide the application of the methoxynickel hydroxide nanosheets in the detection and / or removal of tetracycline antibiotics.

[0009] A fourth objective of this invention is to provide a method for detecting tetracycline antibiotics.

[0010] The fifth object of the present invention is to provide a method for removing tetracycline antibiotics.

[0011] To achieve the above objectives, the present invention is implemented through the following solution: This invention claims protection for the following: A method for preparing methoxy nickel hydroxide nanosheets involves dissolving a soluble nickel metal salt and sodium hydroxide in a methanol solution, mixing and stirring for 10–20 min, reacting at 110–130 °C for 5–18 h, cooling, filtering, washing, and drying at 50–70 °C to obtain the nanosheets.

[0012] Preferably, the molar ratio of the soluble nickel metal salt to sodium hydroxide is 1:0.5 to 2.

[0013] Preferably, the soluble nickel metal salt is nickel acetate tetrahydrate.

[0014] Preferably, the stirring time is 15 min, the reaction temperature is 120°C, the reaction time is 6 h, the washing is performed by washing with methanol 5 times, and the drying temperature is 60°C.

[0015] The method described above prepares methoxy nickel hydroxide nanosheets.

[0016] And the application of the methoxy nickel hydroxide nanosheets in the detection and / or removal of tetracycline antibiotics.

[0017] A method for detecting tetracycline antibiotics includes the following steps: The methoxynickel hydroxide nanosheets were added to the sample solution and stirred. The content of tetracycline antibiotics in the sample was determined based on the color change of the system and the rate of formation of the greenish-yellow precipitate. The specific determination method is as follows: If a bluish-yellow precipitate appears after stirring for more than 3 hours, the concentration of tetracycline antibiotics is determined to be 0–0.1 mg / L. -1 ; A bluish-yellow precipitate appears when stirring for 3 minutes to 3 hours, indicating a tetracycline antibiotic content of 0.1–5 mg / L. -1 ; If a bluish-yellow precipitate appears within 3 minutes of stirring, the concentration of tetracycline antibiotics is determined to be greater than 5 mg / L. -1 .

[0018] A method for removing tetracycline antibiotics involves adding the methoxynickel hydroxide nanosheets to a sample solution and stirring to separate the greenish-yellow precipitate, thereby removing tetracycline antibiotics from the sample.

[0019] Preferably, the tetracycline antibiotic is one or more of oxytetracycline, chlortetracycline, tetracycline, or doxycycline.

[0020] Preferably, the concentration of the tetracycline antibiotic is 0.1–20 mg / L. -1 .

[0021] Preferably, the stirring time is not less than 30 minutes.

[0022] Compared with the prior art, the present invention has the following beneficial effects: This invention develops a method for the detection and removal of tetracycline antibiotics. The method is low-cost, simple in preparation, allows for visual inspection, and efficiently removes tetracycline antibiotics from water, meeting practical production needs and facilitating widespread application. The synthesized sample rapidly captures tetracycline antibiotics in water, undergoing a chemical reaction to form a bluish-yellow precipitate, thus removing the antibiotics. Furthermore, the presence and approximate concentration of tetracycline antibiotics in the water are determined based on the color change and its rate of change. Attached Figure Description

[0023] Figure 1 This diagram illustrates the color change of Ni(OH)OMeNNs reacting with tetracycline; where a is a photograph of Ni(OH)OMeNNs obtained in Example 1, and b is a photograph of Ni(OH)OMeNNs added to 10 mg·L⁻¹. -1 Photographs of tetracycline solution after stirring for 1 min, and c is a photograph of the sample obtained by reacting Ni(OH)OMeNNs with tetracycline.

[0024] Figure 2 The X-ray powder diffraction (XRD) patterns of Ni(OH)OMe NNs obtained in Example 1, Ni(OH)OMe obtained in Comparative Example 1, Ni(OH)2 obtained in Comparative Example 2, and the sample (Ni(OH)OMe NNs-A) after reacting with tetracycline are shown.

[0025] Figure 3 The Fourier transform infrared (FT-IR) spectrum of Ni(OH)OMe NNs obtained in Example 1 is shown.

[0026] Figure 4 The image shows the high-resolution X-ray photoelectron spectroscopy (XPS) Ni 2p spectra of Ni(OH)OMe NNs and Ni(OH)OMe NNs-A obtained in Example 1.

[0027] Figure 5The images are XPS O 1s high-resolution images of Ni(OH)OMe NNs and Ni(OH)OMe NNs-A obtained in Example 1.

[0028] Figure 6 High-resolution XPS N 1s image of Ni(OH)OMe NNs-A.

[0029] Figure 7 The images are scanning electron microscope (SEM) images; where a is the Ni(OH)OMe NNs obtained in Example 1, and b is the Ni(OH)OMe obtained in Comparative Example 1.

[0030] Figure 8 The images show test results for tetracycline removal from Ni(OH)OMe NNs obtained in Example 1, Ni(OH)OMe obtained in Comparative Example 1, and Ni(OH)2 obtained in Comparative Example 2.

[0031] Figure 9 The image shows the removal effect of Ni(OH)OMeNNs obtained in Example 1 on tetracycline of different concentrations.

[0032] Figure 10 The image shows the removal effect of Ni(OH)OMeNNs obtained in Example 1 on different types of antibiotics.

[0033] Figure 11 The image shows the removal effect of Ni(OH)OMeNNs obtained in Example 1 on different types of tetracycline antibiotics. Detailed Implementation

[0034] The present invention will be further illustrated below with reference to specific embodiments, but the embodiments do not limit the present invention in any way. Unless otherwise specified, the reagents, methods, and equipment used in the present invention are conventional reagents, methods, and equipment in this technical field.

[0035] Unless otherwise specified, all reagents and materials used in the following examples are commercially available.

[0036] The above embodiments are preferred embodiments of the present invention, but the embodiments of the present invention are not limited to the above embodiments. Any changes, modifications, substitutions, combinations, or simplifications made without departing from the spirit and principle of the present invention shall be considered equivalent substitutions and shall be included within the protection scope of the present invention.

[0037] Example 1 Synthesis of methoxy nickel hydroxide nanosheets (Ni(OH)OMe NNs) First, 3 mmol of nickel acetate tetrahydrate and 6 mmol of sodium hydroxide were dissolved in 30 mL of methanol solution. The sodium hydroxide methanol solution was then added dropwise to the nickel acetate methanol solution. After stirring for 15 min, the mixture was transferred to a reaction vessel and reacted in an oven at 120 °C for 6 h. After natural cooling, the sample was filtered, washed five times with methanol, and dried at 60 °C to obtain a light green solid powder sample, named Ni(OH)OMeNNs.

[0038] Comparative Example 1: Synthesis of methoxynickel hydroxide (Ni(OH)OMe) First, 3 mmol of nickel acetate tetrahydrate and 6 mmol of sodium hydroxide were weighed and dissolved in 30 mL of methanol solution. The sodium hydroxide solution was added dropwise to the nickel acetate solution and stirred. After stirring for 6 h, the sample was filtered, washed 5 times with methanol, and dried at 60 °C to obtain a dark green solid powder sample, named Ni(OH)OMe.

[0039] Comparative Example 2: Synthesis of Nickel Hydroxide (Ni(OH)2) First, 3 mmol of nickel sulfate hexahydrate and 18 mmol of urea were weighed and dissolved in 30 mL of water respectively. The urea solution was added dropwise to the nickel sulfate solution, and the mixture was stirred for 15 min. The mixture was then transferred to a reaction vessel and reacted in an oven at 170 °C for 18 h. After natural cooling, the sample was filtered, washed five times with deionized water, and dried at 60 °C to obtain a green solid powder sample, which was named Ni(OH)2.

[0040] Comparative Example 3: Reaction of Nickel Metal Salt with Tetracycline First, weigh out 50 mg of nickel metal salts (nickel acetate tetrahydrate, nickel chloride hexahydrate, nickel nitrate hexahydrate, and nickel sulfate hexahydrate), and add them to 100 mL of tetracycline (20 mg·L⁻¹). -1 In the solution, stir for 3 h.

[0041] Test Example 1: Visual Detection of Tetracycline Antibiotics I. Experimental Methods The Ni(OH)OMe NNs prepared in Example 1, the Ni(OH)OMe prepared in Comparative Example 1, the Ni(OH)2 prepared in Comparative Example 2, and the nickel metal salt in Comparative Example 3 were reacted with tetracycline. The specific method is as follows: Ni(OH)OMe NNs: Tetracycline antibiotic solutions of different concentrations were prepared using deionized water, tap water, reservoir water, and seawater, with the lowest concentration being 0.1 mg·L⁻¹. -1 The highest concentration is 20 mg·L. -1 Add 10 mg of Ni(OH)OMeNNs to antibiotic solutions of different concentrations, stir, and observe the rate and amount of color change in the samples.

[0042] Ni(OH)OMe: Prepare a 20 mg·L⁻¹ solution using deionized water. -1 Add 10 mg of Ni(OH)OMe to a tetracycline antibiotic solution, stir, and observe the color change of the sample.

[0043] Ni(OH)₂: Prepare a 20 mg·L⁻¹ solution using deionized water. -1 Add 10 mg of Ni(OH)2 to a tetracycline antibiotic solution, stir, and observe the color change of the sample.

[0044] Nickel metal salts: Weigh 50 mg of nickel metal salts (nickel acetate tetrahydrate, nickel chloride hexahydrate, nickel nitrate hexahydrate, and nickel sulfate hexahydrate), and add to 100 mL of tetracycline (20 mg·L⁻¹). -1 In the solution, stir for 3 h.

[0045] II. Experimental Results like Figure 1 As shown in Table 1, the Ni(OH)OMeNNs sample changed color before and after the reaction, from light green to bluish-yellow. This same change occurred regardless of whether the tetracycline solution was prepared with deionized water or from other water environments (tap water, reservoir water, and seawater). Furthermore, to investigate the tetracycline detection limit of Ni(OH)OMeNNs samples, 10 mg of Ni(OH)OMeNNs sample was dispersed in tetracycline solutions of different concentrations. The study found that the concentration of the tetracycline solution was related to the rate of color change. As shown in Table 1, to produce a bluish-yellow solid from Ni(OH)OMeNNs, 0.1 mg / L... -1 Tetracycline solution requires stirring for more than 3 hours before a very small amount of bluish-yellow solid appears. (0.1–5 mg / L) -1 In tetracycline solution, color change occurs after stirring for 3 min to 3 h. At higher concentrations (greater than 5 mg / L), the color changes. -1 In tetracycline solution, a bluish-yellow precipitate appears within 3 minutes of stirring, especially at a concentration of 10 mg / L. -1 In tetracycline solutions of the above concentrations, the Ni(OH)OMeNNs sample changed color immediately upon addition, producing a large amount of bluish-yellow precipitate. Therefore, the concentration range of tetracycline antibiotics in water can be estimated based on the rate and amount of color change in the Ni(OH)OMeNNs sample.

[0046] Table 1: Relationship between tetracycline solution concentration and the color change rate of Ni(OH)OMeNNs

[0047] The Ni(OH)OMe prepared in Comparative Example 1 underwent a coordination reaction with tetracycline, resulting in a bluish-yellow color. However, this Ni(OH)OMe showed moderate effectiveness (60.2%) in subsequent tetracycline removal experiments, unlike Ni(OH)OMe NNs. The Ni(OH)2 prepared in Comparative Example 2 did not undergo a coordination reaction with tetracycline, resulting in no precipitate formation and no change in solution color before and after preparation.

[0048] In Comparative Example 3, the nickel ions did not undergo a coordination reaction with tetracycline, no precipitate was formed, and the solution color remained unchanged, indicating that this coordination reaction requires an alkaline environment. Therefore, when a small amount of solid sodium hydroxide was added to Comparative Example 3, the solution turned bluish-yellow.

[0049] Test Example 2: Structural Characterization of Ni(OH)OMe NNs, Ni(OH)OMe, Ni(OH)2, and Ni(OH)OMe NNs-A I. Experimental Methods The structures of Ni(OH)OMe NNs prepared in Example 1, Ni(OH)OMe prepared in Comparative Example 1, Ni(OH)2 prepared in Comparative Example 2, and the sample (Ni(OH)OMe NNs-A) after reaction with tetracycline were characterized using the following methods: (1) X-ray powder diffraction (XRD) The phase characteristics of Ni(OH)OMe NNs prepared in Example 1, Ni(OH)OMe prepared in Comparative Example 1, Ni(OH)2 prepared in Comparative Example 2, and the sample of Ni(OH)OMe NNs reacted with tetracycline (Ni(OH)OMe NNs-A) were characterized using an X-ray powder diffractometer (Prouk d8). Test conditions: voltage 40 kV, current 26 mA, scanning angle range 5–70°, scan rate 5° / min, CuKα (λ = 0.154 nm) radiation.

[0050] (2) Fourier transform infrared spectroscopy (FT-IR) The Ni(OH)OMeNNs prepared in Example 1 were subjected to infrared spectroscopy using a Nicolet 6700 Fourier transform infrared spectrometer (USA). Potassium bromide was used as the substrate, and 64 scans were performed, covering a range of 4000–650 cm⁻¹. -1 Resolution 4.0 cm -1 .

[0051] (3) X-ray photoelectron spectroscopy (XPS) Elemental analysis was performed on the Ni(OH)OMeNNs prepared in Example 1 and the sample after the reaction of Ni(OH)OMeNNs with tetracycline (Ni(OH)OMeNNs-A) using X-ray photoelectron spectroscopy (Prouk Axis SUPRA). Al Kα rays were used as the excitation source, and the C1s characteristic peak (284.8 eV) was used as the standard for correction.

[0052] (4) Scanning electron microscope (SEM) The Ni(OH)OMe NNs prepared in Example 1 and the Ni(OH)OMe sample prepared in Comparative Example 1 were ultrasonically dispersed evenly in methanol. The dispersion was dropped onto a silicon wafer and air-dried naturally before being tested using a scanning electron microscope (JSM-7610F, Nippon Electron Ltd.).

[0053] II. Experimental Results (1) X-ray powder diffraction (XRD) like Figure 2 As shown, the synthesized Ni(OH)OMe NNs and Ni(OH)OMe samples have similar XRD peaks, but the peak intensities are low and wide, indicating that the synthesized Ni(OH)OMe material has poor crystallinity and its surface easily exposes a large number of Ni coordination sites, which can then undergo coordination reactions with tetracycline. Both types of Ni(OH)OMe react with tetracycline to form a bluish-yellow precipitate. The XRD peak positions of Ni(OH)OMe NNs did not change before and after the reaction, indicating that the reaction of Ni(OH)OMe NNs with tetracycline did not destroy the main structure of Ni(OH)OMe NNs. Furthermore, the absence of new XRD peaks after the reaction suggests that the resulting complex may be an amorphous substance. The Ni(OH)2 synthesized in Comparative Example 2 is of the β type. The Ni(OH)2 has narrow and strong XRD peaks, exhibiting high crystallinity and virtually no defect exposure. This type of Ni(OH)2 is unlikely to undergo coordination reactions with tetracycline, and experiments have confirmed that it does not react with tetracycline.

[0054] (2) Fourier transform infrared spectroscopy (FT-IR) like Figure 3 The image shows the characteristic spectral lines of Ni(OH)OMeNNs, in the range of 3200–3600 cm⁻¹. -1 The broad peak is attributed to the stretching vibration of the intercalated hydroxyl groups in NiO2, while the peak at approximately 1600 cm⁻¹ is... -1 The signal peak at approximately 1460 cm⁻¹ is attributed to the bending vibrations of the intercalation water. -1 The presence of a stretching vibration peak of the carbonate ion nearby is likely due to the dissolution of carbon dioxide from the air in the solvothermal reaction solution. At approximately 1070 cm⁻¹... -1There is a peak at this point, which is a characteristic absorption peak attributed to the interaction between nickel hydroxide and methoxy groups.

[0055] (3) X-ray photoelectron spectroscopy (XPS) like Figure 4 As shown, Ni(OH)OMe NNs and Ni(OH)OMe NNs-A have similar Ni 2+ Signal peaks, but Ni-complexes Ni 2+ The intensity of the signal peak is significantly weaker than that of Ni(OH)OMe NNs, which may be due to the reaction of Ni(OH)OMe NNs with tetracycline to form a Ni-complex, resulting in a decrease in nickel content.

[0056] like Figure 5 As shown, Ni(OH)OMe NNs and Ni(OH)OMe NNs-A have similar oxygen signal peaks, but the intensity of Ni(OH)OMe NNs-A is significantly weaker than that of Ni(OH)OMe NNs. This may be due to the coordination of tetracycline with unsaturated nickel, resulting in a decrease in oxygen content.

[0057] like Figure 6 As shown, a nitrogen signal peak was observed in Ni(OH)OMe NNs-A, which is attributed to nitrogen in tetracycline. This may be because tetracycline acts as a ligand to form a nickel-based tetracycline complex with the unsaturated nickel in Ni(OH)OMe NNs.

[0058] (4) Scanning electron microscope (SEM) like Figure 7 As shown, Ni(OH)OMe NNs is a nanosheet morphology, while Ni(OH)OMe is a bulk morphology. The nanosheet structure exposes more nickel sites for reaction with tetracycline.

[0059] Test Example 3: Removal of Tetracycline Antibiotics I. Experimental Methods (1) Removal of tetracycline by different synthetic materials 50 mg of Ni(OH)OMe NNs prepared in Example 1, Ni(OH)OMe prepared in Comparative Example 1, and Ni(OH)2 prepared in Comparative Example 2 were dispersed in 20 mg·L⁻¹ -1 In a tetracycline solution, stir for 30 min, take 3 mL of the solution, centrifuge, and collect the supernatant. Calculate the antibiotic removal rate by measuring the absorbance of the antibiotic solution at 357 nm before and after the reaction.

[0060] (2) Removal of tetracycline at different concentrations by Ni(OH)OMeNNs 50 mg of Ni(OH)OMe NNs prepared in Example 1 were dispersed in concentrations of 5, 10, 15, and 20 mg·L⁻¹. -1 In a tetracycline solution, stir for 30 min, take 3 mL of the solution, centrifuge, and collect the supernatant. Calculate the antibiotic removal rate by measuring the absorbance of the antibiotic solution at 357 nm before and after the reaction.

[0061] (3) Removal of different types of antibiotics by Ni(OH)OMeNNs 50 mg of Ni(OH)OMe NNs prepared in Example 1 were dispersed in 20 mg·L⁻¹ solution. -1 The antibiotics were stirred in ciprofloxacin (CF), levofloxacin hydrochloride (LF·HCl) and sulfamethoxazole (SMO) solutions for 30 min. 3 mL of the solution was taken, centrifuged, and the supernatant was collected. The removal rate of the antibiotics was calculated by measuring the absorbance of the antibiotic solutions before and after the reaction at specific wavelengths (ciprofloxacin: 276 nm; levofloxacin hydrochloride: 293 nm; sulfamethoxazole: 256 nm).

[0062] (4) Removal of different types of tetracycline antibiotics by Ni(OH)OMeNNs 50 mg of Ni(OH)OMe NNs prepared in Example 1 were dispersed in 20 mg·L⁻¹ solution. -1 The solutions of oxytetracycline (OTC), chlortetracycline hydrochloride (CTC·HCl), tetracycline hydrochloride (TC·HCl), and doxycycline hydrochloride (DHO) were stirred for 30 min. 3 mL of the solution was taken, centrifuged, and the supernatant was collected. The removal rate of antibiotics was calculated by measuring the absorbance of the antibiotic solutions before and after the reaction at specific wavelengths (oxytetracycline: 354 nm; chlortetracycline hydrochloride: 367 nm; tetracycline hydrochloride: 357 nm; doxycycline hydrochloride: 350 nm).

[0063] II. Experimental Results like Figure 8 As shown, Ni(OH)OMe NNs exhibited excellent tetracycline removal capability, reaching 99.5%, while the removal rate of bulk Ni(OH)OMe was 60.2%. Compared with the bulk form, the nanosheets exposed more nickel sites to react with tetracycline, thus playing a role in removal. In contrast, Ni(OH)2 showed a very low removal capability (4.8%), which was mainly due to the sample's adsorption capacity adsorbing tetracycline onto the sample surface.

[0064] like Figure 9 As shown, the Ni(OH)OMeNNs samples exhibited excellent antibiotic removal efficiency, reaching over 99%, at different concentrations of tetracycline.

[0065] like Figure 10 As shown, the Ni(OH)OMeNNs sample exhibits very poor removal efficiency for ciprofloxacin (CF), levofloxacin hydrochloride (LF·HCl), and sulfamethoxazole (SMO), relying primarily on the sample's adsorption capacity for removal. This is because these antibiotics lack coordinating groups to coordinate with nickel ions.

[0066] like Figure 11 As shown, Ni(OH)OMe NNs achieved a removal rate of over 98% for oxytetracycline (OTC), chlortetracycline hydrochloride (CTC·HCl), tetracycline hydrochloride (TC·HCl), and doxycycline hydrochloride (DHO) within a short period of time. This was mainly due to the coordination reaction between nickel sites and tetracycline antibiotics, thus achieving the goal of efficiently removing tetracycline antibiotics from water.

Claims

1. A method for preparing methoxy nickel hydroxide nanosheets, characterized in that, Soluble nickel metal salt and sodium hydroxide are dissolved in methanol solution, mixed and stirred for 10-20 min, reacted at 110-130℃ for 5-18 h, cooled, filtered, washed, and dried at 50-70℃ to obtain the final product.

2. The preparation method according to claim 1, characterized in that, The molar ratio of the soluble nickel metal salt to sodium hydroxide is 1:0.5 to 2.

3. The preparation method according to claim 1, characterized in that, The soluble nickel metal salt is nickel acetate tetrahydrate.

4. Methoxylated nickel hydroxide nanosheets prepared by the preparation method according to any one of claims 1 to 3.

5. The use of the methoxynickel hydroxide nanosheets of claim 4 in the detection and / or removal of tetracycline antibiotics.

6. A method for detecting tetracycline antibiotics, characterized in that, Includes the following steps: The methoxy nickel hydroxide nanosheets described in claim 4 are added to the sample solution and stirred. The content of tetracycline antibiotics in the sample is determined based on the color change of the system and the rate of formation of the greenish-yellow precipitate. The specific determination method is as follows: If a bluish-yellow precipitate appears after stirring for more than 3 hours, the concentration of tetracycline antibiotics is determined to be 0–0.1 mg / L. -1 ; A bluish-yellow precipitate appears when stirring for 3 minutes to 3 hours, indicating a tetracycline antibiotic content of 0.1–5 mg / L. -1 ; If a bluish-yellow precipitate appears within 3 minutes of stirring, the concentration of tetracycline antibiotics is determined to be greater than 5 mg / L. -1 .

7. A method for removing tetracycline antibiotics, characterized in that, The methoxy nickel hydroxide nanosheets of claim 4 are added to the sample solution to be tested and stirred to separate the greenish-yellow precipitate in order to remove tetracycline antibiotics from the sample.

8. The method according to claim 6 or 7, characterized in that, The tetracycline antibiotics are one or more of oxytetracycline, chlortetracycline, tetracycline, or doxycycline.

9. The method according to claim 6, characterized in that, The concentration of the tetracycline antibiotic is 0.1–20 mg / L. -1 .

10. The method according to claim 7, characterized in that, The stirring time shall be no less than 30 minutes.

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