Terramycin detection and removal double-effect integrated composite material and preparation method thereof

Abstract

The invention discloses an oxytetracycline detection and removal double-effect integrated composite material and a preparation method thereof, and belongs to the technical field of environmental remediation and drug residue treatment.The preparation method comprises the steps that firstly, ZIF-8 is subjected to acid etching, and ZIF-8 of a cavity structure is obtained; the preparation method comprises the following steps: preparing ZIF-8 with a cavity structure, then injecting fluorescein into a cavity of the ZIF-8 with the cavity structure, then growing a ZIF-8 shell layer on the surface of the ZIF-8, and loading CDs-Eu < 3 + > in situ to obtain the terramycin detection and removal double-effect integrated composite material. Target molecules can be accurately recognized in complex matrixes (such as water, soil and food), the anti-interference performance is high, and the detection limit is low.

Description

Technical Field

[0001] The present invention belongs to the technical field of environmental remediation and drug residue treatment, and in particular relates to a composite material capable of combining oxytetracycline detection and removal and a preparation method thereof. Background Art

[0002] Oxytetracycline, a broad-spectrum antibiotic, has long played a central role in disease prevention and control in veterinary medicine and animal husbandry. However, its overuse and improper disposal have posed a dual threat: on the one hand, drug residues continue to contaminate water, soil, and agricultural products through runoff and leaching, severely disrupting the balance of material cycles in the ecosystem; on the other hand, the selective pressure exerted by residues in the environment accelerates the spread of drug-resistant genes, leading to the emergence of multidrug-resistant strains. These resistant microorganisms can accumulate and spread through the food chain. When humans consume contaminated drinking water or food, they may cause health risks such as intestinal dysbiosis and abnormal immune responses, and even undermine the effectiveness of clinical anti-infective treatments. Therefore, accurate and sensitive detection of oxytetracycline is crucial for monitoring environmental quality, ensuring food safety, and protecting public health.

[0003] Liquid chromatography-tandem mass spectrometry (LC-MS), microbial detection, and enzyme-linked immunosorbent assay (ELISA) have been widely used for antibiotic detection. However, their relatively high cost and bulky nature make them difficult to carry and prevent in situ detection. Summary of the Invention

[0004] To address these technical issues, the present invention proposes a composite material that combines the detection and removal of oxytetracycline and its preparation method. The composite material prepared in this invention is a ZIF-8 composite material with dual detection and photocatalytic functions. This material can detect and remove oxytetracycline, providing a new method for detecting and removing oxytetracycline in soil, water, and food.

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

[0006] The present invention provides a preparation method of a composite material with dual effects of oxytetracycline detection and removal. First, ZIF-8 is acid-etched to obtain ZIF-8 with a cavity structure; then fluorescein is injected into the cavity of the ZIF-8 with the cavity structure, and then a ZIF-8 shell is grown on the surface of the ZIF-8 shell to in-situ load CDs-Eu. 3+ , and obtain the composite material that combines the detection and removal effects of oxytetracycline.

[0007] The composite material for oxytetracycline detection and removal has high selectivity and sensitivity to oxytetracycline, can accurately identify target molecules in complex matrices (such as water, soil, and food), has strong anti-interference ability, and has a low detection limit. Oxytetracycline can bind to ZIF-8@LY / ZIF-8@CDs-Eu through antenna effect. 3+ Eu in materials 3+ Combined, through Eu 3+ The transition of ZIF-8@LY / ZIF-8@CDs-Eu can enhance the fluorescence intensity and detect oxytetracycline. 3+ The fluorescein in the material can catalyze the water in the mixed solution containing oxytetracycline and O2 in the air to produce free radicals 1 O2, through the combination of free radicals and oxytetracycline, can achieve the degradation of oxytetracycline. These two processes can be carried out simultaneously, so the composite material can simultaneously detect and remove oxytetracycline.

[0008] Furthermore, the preparation method of the composite material with dual effects of oxytetracycline detection and removal comprises the following steps:

[0009] S1. Exposing ZIF-8 to acetic acid vapor to obtain ZIF-8 with a cavity structure;

[0010] S2. An ethanol solution of fluorescein (LY) was injected into the cavity of the ZIF-8 having a cavity structure, and after washing and drying, ZIF-8@LY was obtained;

[0011] S3. Add citric acid and europium nitrate hexahydrate (Eu(NO3)3·6H2O) to water, stir, then add urea and formic acid to obtain a mixed solution, react the mixed solution at 160°C for 4 hours, mix the reacted solution with ethanol, and centrifuge to obtain CDs-Eu 3+ ;

[0012] S4. Add the aqueous solution containing ZIF-8@LY to the aqueous solution of 2-methylimidazole containing hexadecyltrimethylammonium bromide (CTAB), and then add CDs-Eu 3+ The solution was stirred, and then zinc nitrate hexahydrate (Zn(NO3)2·6H2O) solution was added. After stirring, it was allowed to stand. After washing and drying, the composite material for the detection and removal of oxytetracycline was obtained, which was recorded as ZIF-8@LY / ZIF-8@CDs-Eu. 3+ .

[0013] Furthermore, in step S2, the concentration of the fluorescein ethanol solution is 0.5 mg / mL.

[0014] Furthermore, in step S3, the usage ratio of citric acid, Eu(NO3)3·6H2O, urea and formic acid is 2g:1g:4g:20mL.

[0015] Furthermore, in step S4, the concentration of the aqueous solution containing ZIF-8@LY is 1 mg / mL.

[0016] Furthermore, in step S4, the preparation step of the 2-methylimidazole aqueous solution containing hexadecyltrimethylammonium bromide is: adding 1.75 mg of hexadecyltrimethylammonium bromide and 565 mg of 2-methylimidazole to 8.5 mL of water and stirring evenly.

[0017] Furthermore, in step S4, the CDs-Eu 3+ The preparation steps of the solution are as follows: 0.4g CDs-Eu 3+ Add 10mL of ethanol to obtain CDs-Eu 3+ Ethanol solution; take 2mL of the above CDs-Eu 3+ The ethanol solution was added to 8 mL of ethanol to obtain CDs-Eu 3+ solution.

[0018] Furthermore, in step S4, the preparation step of the Zn(NO3)2·6H2O solution is as follows: 36.255 mg of Zn(NO3)2·6H2O is added to 1.25 mL of deionized water and stirred evenly.

[0019] Exemplarily, in step S4, drying is performed in a vacuum drying oven at a temperature of 60° C. for 6 hours.

[0020] The present invention also provides a composite material for combining oxytetracycline detection and removal prepared according to the above method.

[0021] The present invention also provides the use of the above-mentioned composite material for detecting and removing oxytetracycline in detecting and / or removing oxytetracycline. For example, the composite material for detecting and removing oxytetracycline provided by the present invention can detect and / or remove oxytetracycline in water, soil, and food.

[0022] The present invention also provides a sensor for detecting oxytetracycline, the active ingredient of which is the above-mentioned composite material with dual effects of oxytetracycline detection and removal.

[0023] The present invention also provides a method for detecting oxytetracycline, wherein the composite material having dual effects of oxytetracycline detection and removal is added to a substance to be tested, and a fluorescence spectrophotometer is used to measure the emission spectrum under 410 nm excitation.

[0024] Compared with the prior art, the present invention has the following advantages and technical effects:

[0025] The present invention first obtains a ZIF-8 porous material with exposed pores by modifying the channels of ZIF-8; then, fluorescein (LY) is loaded into its pores; then, a ZIF-8 shell is grown on its surface and CDs-Eu is in situ loaded. 3+ Finally, a composite material ZIF-8@LY / ZIF-8@CDs-Eu with dual functions of detection and photocatalysis was prepared. 3+ The composite material can detect and remove oxytetracycline, providing a new method for the detection and removal of oxytetracycline in soil, water and food.

[0026] The preparation method of the present invention is simple, ZIF-8@LY / ZIF-8@CDs-Eu 3+ It has strong anti-interference ability and low detection limit. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] The accompanying drawings, which constitute part of the present invention, are provided to provide a further understanding of the present invention. The exemplary embodiments of the present invention and their descriptions are provided to explain the present invention and do not constitute an undue limitation of the present invention. In the accompanying drawings:

[0028] Figure 1 a) is the ZIF-8@LY / ZIF-8@CDs-Eu prepared in Example 1 3+ SEM and EDS images of ZIF-8@LY / ZIF-8@CDs-Eu prepared in Example 1; b) ZIF-8@LY / ZIF-8@CDs-Eu prepared in Example 1 3+ 、ZIF-8@LY / ZIF-8@CDs-Eu 3+ @OTC and ZIF-8@LY / ZIF-8@CDs-Eu 3+ XRD spectrum of @OTC@hv 2h; c) OTC, ZIF-8@LY / ZIF-8@CDs-Eu prepared in Example 1 3+ 、ZIF-8@LY / ZIF-8@CDs-Eu 3+ +OTC+hv 2h and ZIF-8@LY / ZIF-8@CDs-Eu 3+ +OTC infrared spectrum, where 1 is OTC, 2 is ZIF-8@LY / ZIF-8@CDs-Eu prepared in this example 3+ , 3 is ZIF-8@LY / ZIF-8@CDs-Eu 3+ +OTC+hv 2h, 4 is ZIF-8@LY / ZIF-8@CDs-Eu 3+ +OTC;

[0029] Figure 2 ZIF-8@LY / ZIF-8@CDs-Eu prepared in Example 1 3+XPS spectrum of

[0030] Figure 3 a) is ZIF-8@LY / ZIF-8@CDs-Eu 3+ Fluorescence spectrum of ZIF-8@LY / ZIF-8@CDs-Eu as the concentration of OTC solution changes. 3+ Linear graph of the change with the concentration of OTC solution. The illustration in b) shows the ZIF-8@LY / ZIF-8@CDs-Eu under 365nm UV light irradiation. 3+ Fluorescence images of the changes with OTC concentration, (I 525 / I 620 )0 represents the ratio of the fluorescence peaks at 525nm and 620nm when the material does not contain oxytetracycline, (I 525 / I 620 ) i It represents the ratio of the fluorescence peak values ​​i at 525 nm and 620 nm when the material contains oxytetracycline.

[0031] Figure 4 a) Different antibiotics were added to ZIF-8@LY / ZIF-8@CDs-Eu 3+ Fluorescence spectra in solution, b) different antibiotics added to ZIF-8@LY / ZIF-8@CDs-Eu 3+ Fluorescence histogram in the solution, c) is the fluorescence of different antibiotics added to ZIF-8@LY / ZIF-8@CDs-Eu under 365nm UV light 3+ Fluorescence images in solution, where 1 is glucose, 2 is oxytetracycline, 3 is ampicillin, 4 is L-cysteine, 5 is alanine, 6 is glycine, 7 is glutathione, 8 is arginine, 9 is kanamycin, 10 is streptomycin, 11 is leucine, 12 is chloramphenicol, 13 is proline, 14 is gentamicin, 15 is serine, 16 is threonine, 17 is valine, 18 is neomycin, 19 is histidine, and 20 is blank;

[0032] Figure 5a) is a fluorescence spectrum of a mixed solution of OTC and other substances, b) is a fluorescence histogram of a mixed solution of OTC and other substances, c) is a fluorescence image of a mixed solution of OTC and other substances under 365 nm ultraviolet light, wherein 1 is oxytetracycline, 2 is glucose, 3 is ampicillin, 4 is cysteine, 5 is alanine, 6 is glycine, 7 is glutathione, 8 is arginine, 9 is kanamycin, 10 is streptomycin, 11 is leucine, 12 is chloramphenicol, 13 is proline, 14 is gentamicin, 15 is serine, 16 is threonine, 17 is valine, 18 is neomycin, and 19 is histidine;

[0033] Figure 6 ZIF-8@LY / ZIF-8@CDs-Eu under fluorescent light 3+ The results of catalytic degradation of oxytetracycline, wherein a) is the catalytic degradation curve of oxytetracycline under fluorescent light irradiation; b) is a linear graph showing the absorbance value of oxytetracycline changing with time under fluorescent light irradiation;

[0034] Figure 7 ZIF-8@LY / ZIF-8@CDs-Eu under mercury lamp irradiation 3+ The results of catalytic degradation of oxytetracycline, wherein a) is the catalytic degradation curve of oxytetracycline under mercury lamp irradiation; b) is a linear graph of the absorbance value of oxytetracycline changing with time under mercury lamp irradiation;

[0035] Figure 8 The fluorescence spectra of the composite material of ZIF-8 and LY prepared after etching in acetic acid vapor in Example 1 and the composite material of ZIF-8 and LY prepared without etching in acetic acid vapor in Comparative Example 1 are shown, wherein ZIF-8(OAC)@LY represents the composite material of Example 1, and ZIF-8@LY represents the composite material of Comparative Example 1;

[0036] Figure 9 Example 1: Eu loaded on carbon dots 3+ The prepared ZIF-8(OAC)@LY and CDs-Eu 3+ The composite material prepared in Example 2 and the one not loaded with Eu on the carbon dots 3+ Prepared ZIF-8(OAC)@LY and Eu 3+ The fluorescence spectrum of the composite material ZIF-8@LY / ZIF-8@CDs-Eu 3+ The composite material of Example 1, ZIF-8@LY@Eu 3+ This represents the composite material of Comparative Example 2. DETAILED DESCRIPTION

[0037] Various exemplary embodiments of the present invention will now be described in detail. This detailed description should not be considered as limiting the present invention, but rather as a more detailed description of certain aspects, features, and embodiments of the present invention.

[0038] It should be understood that the terms described herein are intended only to describe particular embodiments and are not intended to limit the present invention. In addition, for numerical ranges herein, it should be understood that each intermediate value between the upper and lower limits of the range is also specifically disclosed. Each smaller range between any intermediate value within a stated value or stated range and any other stated value or intermediate value within the stated range is also encompassed by the present invention. The upper and lower limits of these smaller ranges may be independently included or excluded within the scope.

[0039] Unless otherwise indicated, all technical and scientific terms used herein have the same meaning as commonly understood by those skilled in the art. Although only preferred methods and materials are described herein, any methods and materials similar or equivalent to those described herein may also be used in the practice 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 associated with the documents. In the event of any conflict with any incorporated document, the contents of this specification shall prevail.

[0040] It will be apparent to those skilled in the art that various modifications and variations may be made to the specific embodiments described herein without departing from the scope or spirit of the invention. Other embodiments will be apparent to those skilled in the art from the description of the invention. The description and examples are intended to be exemplary only.

[0041] The words “include,” “including,” “have,” “contain,” etc. used in this document are open-ended terms, meaning including but not limited to.

[0042] After synthesizing ZIF-8, the present invention carries out acidification treatment (etching treatment) on ZIF-8. The acidified ZIF-8 has a gap, and a cavity is formed inside. Its purpose is to load more fluorescein in the next step. Fluorescein, as a kind of oxidase substance, can degrade oxytetracycline. To prevent the outflow of fluorescein, the present invention also carries out a "hole sealing" process. The ZIF-8 loaded with fluorescein is placed in the precursor solution of ZIF-8, and the gap of ZIF-8 is filled by the method of resynthesis. In this process, CDs-Eu is also added. 3+ solution, through Eu 3+ The coordination effect with oxytetracycline can achieve sensitive detection of oxytetracycline with a detection limit as low as 1.8nM. 3+Sensitive detection and effective degradation of oxytetracycline can be achieved.

[0043] Unless otherwise specified, the room temperature in the present invention is 25±2°C.

[0044] All raw materials used in the examples of the present invention are commercially available.

[0045] It should be pointed out that the matters not described in detail in the present invention are conventional operating means in this field and are not the focus of the present invention.

[0046] The technical solution of the present invention is further illustrated by the following examples.

[0047] Example 1

[0048] This embodiment provides a method for preparing a composite material that combines the detection and removal of oxytetracycline. The steps are as follows:

[0049] S1. Synthesis and Etching of ZIF-8

[0050] Take 0.3 g of Zn(OAc)2·2H2O and dissolve it in 7 mL of deionized water to obtain solution A; take 1.12 g of 2-methylimidazole and dissolve it in 7 mL of deionized water to obtain solution B; after mixing solution A and solution B, magnetic stirring is carried out for 10 seconds, and the mixed solution is left to stand at room temperature for 12 hours, washed with methanol three times, and the product is collected and placed in a vacuum drying oven at 80°C overnight to obtain ZIF-8; then, ZIF-8 (20 mg) is exposed to acetic acid vapor for 1 hour to obtain etched ZIF-8 (i.e., ZIF-8 with a cavity structure), which is a particle with a cavity structure.

[0051] S2. Synthesis of ZIF-8@LY

[0052] 10 mL of fluorescein (LY) ethanol solution (0.5 mg / mL) was mixed with the above-etched ZIF-8, soaked for 5 minutes, washed with methanol three times, and dried in a vacuum drying oven at 60°C for 6 hours to obtain ZIF-8@LY.

[0053] S3. Synthesis of CDs-Eu 3+

[0054] Take 2g citric acid (CA) and 1g Eu(NO3)3·6H2O and dissolve them in 10mL deionized water, stir for 20min, add 4g urea and 20mL formic acid to obtain a mixed solution; transfer the mixed solution to a reactor, react at 160℃ for 4h, mix the obtained red solution with 40mL ethanol, centrifuge at 10000rpm for 5min, wash and centrifuge to obtain CDs-Eu 3+ Solid, refrigerate overnight.

[0055] S4. Synthesis of ZIF-8@LY / ZIF-8@CDs-Eu 3+

[0056] 0.4 g CDs-Eu 3+ The solid was added to 10 mL of ethanol to obtain CDs-Eu 3+ Ethanol solution; take 2mL of the above CDs-Eu 3 + The ethanol solution was added to 8 mL of ethanol to obtain CDs-Eu 3+ Solution; Take 1 mL of ZIF-8@LY aqueous solution (1 mg / mL), add it to 8.5 mL of 2-methylimidazole (565 mg) aqueous solution containing CTAB (1.75 mg), and then add 700 μL of the above CDs-Eu 3+ The mixture was stirred at 500 rpm for 1 min to obtain a mixed solution; 1.25 mL of Zn(NO3)2·6H2O (36.255 mg) aqueous solution was added to the mixed solution, stirred for 5 min, allowed to stand at room temperature for 1 h, washed with water 3 times, and dried in a vacuum drying oven at 60 ° C for 6 h to obtain ZIF-8@LY / ZIF-8@CDs-Eu 3+ .

[0057] ZIF-8@LY / ZIF-8@CDs-Eu prepared in this example 3+ It is a dual-emission material, and its SEM and EDS images are as follows Figure 1 As shown in a), it can be seen that the final product ZIF-8@LY / ZIF-8@CDs-Eu 3+ The morphology is the same as that of the original ZIF-8. The C, Zn, O, Na, N and Eu elements are present in ZIF-8@LY / ZIF-8@CDs-Eu. 3+ Evenly distributed in the 3+ and carbon quantum dots were successfully loaded onto ZIF-8.

[0058] In order to verify the ZIF-8@LY / ZIF-8@CDs-Eu prepared in Example 1 3+ Will the crystal structure of the dual-emission material be destroyed after being tested with oxytetracycline? -3 M of oxytetracycline solution was added dropwise to the ZIF-8@LY / ZIF-8@CDs-Eu prepared in Example 1. 3+ The material obtained after drying is recorded as ZIF-8@LY / ZIF-8@CDs-Eu 3+ @OTC; will be 10 -3 M of oxytetracycline solution was added dropwise to the ZIF-8@LY / ZIF-8@CDs-Eu prepared in Example 1. 3+The material obtained after drying was irradiated with fluorescent light for 2 h and was named ZIF-8@LY / ZIF-8@CDs-Eu 3+ @OTC@hv 2h.

[0059] ZIF-8@LY / ZIF-8@CDs-Eu prepared in this example 3+ 、ZIF-8@LY / ZIF-8@CDs-Eu 3+ @OTC and ZIF-8@LY / ZIF-8@CDs-Eu 3+ The XRD spectrum of @OTC@hv 2h is as follows Figure 1 As shown in b), it can be seen that the composite (ZIF-8@LY / ZIF-8@CDs-Eu 3+ ) is the same as that of the original ZIF-8, indicating that carbon quantum dots, Eu 3+ Functionalization with fluorescein does not destroy the crystal structure, and catalytic OTC does not change the ZIF-8@LY / ZIF-8@CDs-Eu 3+ crystal structure.

[0060] OTC, ZIF-8@LY / ZIF-8@CDs-Eu prepared in this example 3+ 、ZIF-8@LY / ZIF-8@CDs-Eu 3+ +OTC+hv 2h and ZIF-8@LY / ZIF-8@CDs-Eu 3+ +OTC infrared spectrum Figure 1 c) (where 1 is OTC, 2 is ZIF-8@LY / ZIF-8@CDs-Eu prepared in this example 3+ , 3 is ZIF-8@LY / ZIF-8@CDs-Eu 3+ +OTC+hv 2h, 4 is ZIF-8@LY / ZIF-8@CDs-Eu 3+ +OTC), it can be seen that oxytetracycline and ZIF-8@LY / ZIF-8@CDs-Eu 3+ There is interaction between them, but it is not enough to destroy the ZIF-8@LY / ZIF-8@CDs-Eu 3+ crystal structure.

[0061] In order to demonstrate that ZIF-8 and guest ions LY / Eu 3+ The weak interaction between ZIF-8@LY / ZIF-8@CDs-Eu prepared in this example 3+ X-ray photoelectron spectroscopy (XPS) test was performed, and the results were as follows Figure 2As shown, the XPS peak with a binding energy of 1070.603 eV is attributed to the Na 1s orbital. For the chemical binding state of Eu, the two peaks at 1195.083 eV and 1134.203 eV belong to Eu 3d, which can be explained by the 3+ Therefore, the above evidence confirms that the ZIF-8@LY / ZIF-8@CDs-Eu 3+ Successful preparation of hybrids.

[0062] The ZIF-8@LY / ZIF-8@CDs-Eu prepared in Example 1 3+ For fluorescence detection of oxytetracycline, the specific steps are as follows:

[0063] ZIF-8@LY / ZIF-8@CDs-Eu 3+ (10 mg) was dispersed in 10 mL of deionized water and ultrasonically dispersed for 5 min. Then, 200 μL of the above solution was added to a cuvette containing 2 mL of deionized water, and 1 μL of oxytetracycline solution (10 -4 M), wait 30 seconds after each injection of oxytetracycline solution, and collect the fluorescence spectrum until the titration endpoint. The emission spectrum is measured using a fluorescence spectrophotometer under excitation at 410 nm.

[0064] The present invention conducted a concentration-dependent (0-1 μM) fluorescence experiment. Under a 365 nm ultraviolet lamp, when OTC was added, the fluorescence color changed from lavender to orange-red (e.g. Figure 3 As shown in the illustration in b). 525 / I 620 The change of the ratio is related to the ZIF-8@LY / ZIF-8@CDs-Eu 3+ The degree of change in OTC concentration is closely related to Figure 3 As shown in b), Δ[(I 525 / I 620 )0 / (I 525 / I 620 ) i The ratio of ] to ΔOTC showed a good linear relationship in the range of 0-1 μM. 525 / I 620 )0 represents the ratio of the fluorescence peaks at 525nm and 620nm when the material does not contain oxytetracycline, (I 525 / I 620 ) i It represents the ratio of the fluorescence peak values ​​i at 525 nm and 620 nm when the material contains oxytetracycline, Δ[(I 525 / I 620 )0 / (I 525 / I 620 ) i] indicates (I 525 / I 620 )0 / (I 525 / I 620 ) i The ratio increment, ΔOTC, represents the concentration increment of oxytetracycline (OTC), which is consistent with the equation: Y = 0.98453 + 3.20605X, and the correlation coefficient (R 2 ) is 0.998, Y represents Δ(I 525 / I 620 )0 / (I 525 / I 620 ) i , X represents the OTC concentration (μM). The detection limit calculated based on 3σ / m (where σ represents the standard deviation of blank measurements and m is the slope of the linear curve) was 1.8 nM.

[0065] The ZIF-8@LY / ZIF-8@CDs-Eu prepared in Example 1 3+ It is used for fluorescence detection of different types of antibiotics (glucose, ampicillin, L-cysteine, alanine, glycine, glutathione, arginine, kanamycin, streptomycin, leucine, chloramphenicol, proline, gentamicin, serine, threonine, valine, novobiocin, histidine). The specific method is as follows: ZIF-8@LY / ZIF-8@CDs-Eu 3+ The probe (10 mg) was dispersed in 10 mL of aqueous solution and ultrasonically dispersed for 5 min. Then, 200 μL of the above solution was added to a cuvette containing 2 mL of deionized water. Then, 20 μL of antibiotic solution was added to the cuvette. After each antibiotic was tested, fluorescence data was collected, the cuvette was cleaned, and the above operation was repeated to test the next antibiotic. The above antibiotic concentrations were all 10 -3 M, fluorescence excitation wavelength is 410 nm.

[0066] ZIF-8@LY / ZIF-8@CDs-Eu prepared in Example 1 3+ The results of fluorescence detection of different types of antibiotics are as follows Figure 4 As shown, Figure 4As shown in a) and b), when different types of antibiotics were injected into ZIF-8@LY / ZIF-8@CDs-Eu 3+ When in solution, the observed changes were negligible except for OTC (oxytetracycline). 3+ In the system, the fluorescence intensity increased significantly after adding OTC, indicating that the dual-emission ZIF-8@LY / ZIF-8@CDs-Eu 3 + It has the ability to selectively identify OTC in aqueous solution. The corresponding fluorescence images also confirmed that this dual-emission sensor has a special response to OTC ( Figure 4 c)).

[0067] The present invention also determined the effect of ZIF-8@LY / ZIF-8@CDs-Eu on the coexistence of OTC with other substances (glucose, ampicillin, cysteine, alanine, glycine, glutathione, arginine, kanamycin, streptomycin, leucine, chloramphenicol, proline, gentamicin, serine, threonine, valine, neomycin and histidine). 3+ The anti-interference performance of OTC was tested by: ZIF-8@LY / ZIF-8@CDs-Eu 3+ (10 mg) was dispersed in 10 mL of aqueous solution and ultrasonically dispersed for 5 min. Then, 200 μL of the above solution and 20 μL of oxytetracycline solution were added to a cuvette containing 2 mL of deionized water. Then, 20 μL of antibiotic solution was added to the cuvette. After each antibiotic was tested, fluorescence data was collected, the cuvette was cleaned, and the above operation was repeated to test the next antibiotic. The above antibiotic concentrations were all 10 -3 M, oxytetracycline concentration was 10 -4 M, the fluorescence excitation wavelength is 410nm. Figure 5 As shown, the results show that the changes in the luminescence intensity at 525nm and 620nm caused by other interferents are almost negligible.

[0068] The ZIF-8@LY / ZIF-8@CDs-Eu prepared in Example 1 3+ For photocatalytic degradation of oxytetracycline, the specific steps are as follows:

[0069] Disperse 10 mg of OTC (oxytetracycline) in 4 mL of ethanol, and then take 20 mg of ZIF-8@LY / ZIF-8@CDs-Eu 3+The material was dispersed in 1 mL of ethanol, the two solutions were mixed, stirred in a dark environment for 30 minutes, and then irradiated under a fluorescent lamp (power of 12 W) and a mercury lamp (power of 500 W), respectively. 100 μL was taken from the mixed solution every five minutes, filtered to obtain a clear solution, and the UV curve was measured using a UV spectrophotometer.

[0070] ZIF-8@LY / ZIF-8@CDs-Eu under fluorescent light irradiation 3+ The results of catalytic degradation of oxytetracycline are as follows Figure 6 As shown, ZIF-8@LY / ZIF-8@CDs-Eu under mercury lamp irradiation 3+ The results of catalytic degradation of oxytetracycline are as follows Figure 7 As shown in the figure, it can be seen that under the irradiation of these two lamps, the degradation rate and efficiency of oxytetracycline are not much different. 3+ The catalytic degradation of oxytetracycline can be carried out under normal light conditions, which simplifies the catalytic degradation process.

[0071] from Figure 6 As shown in a), with the increase of illumination time, the UV absorption peak of oxytetracycline becomes lower and lower, which shows that under the illumination conditions of ordinary fluorescent light, the photocatalytic material ZIF-8@LY / ZIF-8@CDs-Eu of the present invention 3+ Can degrade oxytetracycline. Figure 6 b) The linear graph of the absorbance of oxytetracycline under fluorescent light over time shows that y = 0.64373*exp(-x / 17.60465)+0.41284, R 2 =0.991, where y represents A t / A0,A t represents the absorbance value of oxytetracycline after t min of ordinary fluorescent light irradiation, A0 represents the absorbance value of oxytetracycline when 0 min of ordinary fluorescent light irradiation is applied, and x represents the illumination time t (min).

[0072] from Figure 7 As shown in a), with the increase of illumination time, the ultraviolet absorption peak of oxytetracycline becomes lower and lower, which shows that under the conditions of mercury lamp illumination, the photocatalytic material ZIF-8@LY / ZIF-8@CDs-Eu of the present invention 3+ It can also degrade oxytetracycline. Figure 7 b) The linear graph of the absorbance of oxytetracycline under mercury lamp irradiation versus time shows that y = 0.4475*exp(-x / 52.44595)+0.55922, R 2 =0.99, where y represents A t ' / A0', A t' represents the absorbance value of oxytetracycline after mercury lamp irradiation for t min, A0' represents the absorbance value of oxytetracycline when the mercury lamp is irradiated for 0 min, and x represents the illumination time t (min).

[0073] Comparative Example 1

[0074] The same as Example 1, except that after the ZIF-8 was obtained in S1, it was not exposed to acetic acid vapor for etching.

[0075] The ZIF-8 obtained by etching without exposure to acetic acid vapor is different from the ZIF-8 etched by acetic acid vapor (OAC). Figure 8 From the fluorescence spectrum, it can be seen that the fluorescence peak at 525 nm is low. It is speculated that ZIF-8 (OAC) obtained by etching in acetic acid vapor can allow more fluorescein molecules to enter the cavity of ZIF-8 within 5 minutes, providing better performance for subsequent experiments.

[0076] Comparative Example 2

[0077] Same as Example 1, except that after ZIF-8@LY was obtained in S1, Eu was not loaded on carbon dots. 3+ Instead, 20 mg of the obtained ZIF-8@LY was placed in an aqueous solution of europium nitrate hexahydrate (10 -2 M) for two hours, Figure 9 It can be seen that in this method, Eu 3+ It was not successfully loaded onto ZIF-8@LY. In Example 1, Eu 3+ Successfully loaded onto ZIF-8@LY.

[0078] This comparative example proves that if Eu 3+ Instead of loading onto carbon dots, Eu was directly loaded onto ZIF-8@LY. 3+ , it cannot be loaded, proving that carbon dots are loaded with Eu 3+ The necessity of this step.

[0079] The above are merely preferred embodiments of the present invention, but the scope of protection of the present invention is not limited thereto. Any changes or substitutions that can be easily conceived by a person skilled in the art within the technical scope disclosed in the present invention should be included in the scope of protection of the present invention. Therefore, the scope of protection of the present invention should be based on the scope of protection of the claims.

Claims

1. A method for preparing a composite material with dual effects of oxytetracycline detection and removal, characterized in that: First, ZIF-8 is acid-etched to obtain ZIF-8 with a cavity structure; then fluorescein is injected into the cavity of the ZIF-8 with a cavity structure, and then a ZIF-8 shell is grown on its surface to in-situ load CDs-Eu. 3+ , and obtain the composite material that combines the detection and removal effects of oxytetracycline.

2. The method for preparing the composite material with dual-effects of oxytetracycline detection and removal according to claim 1, characterized in that: The following steps are involved: S1. Exposing ZIF-8 to acetic acid vapor to obtain ZIF-8 with a cavity structure; S2. Injecting an ethanol solution of fluorescein into the cavity of the ZIF-8 having a cavity structure, washing and drying to obtain ZIF-8@LY; S3. Add citric acid and europium nitrate hexahydrate to water, stir, add urea and formic acid to obtain a mixed solution, react the mixed solution at 160 ° C for 4 hours, mix the reacted solution with ethanol, and centrifuge to obtain CDs-Eu 3+ ; S4. Add the aqueous solution containing ZIF-8@LY to the aqueous solution of 2-methylimidazole containing hexadecyltrimethylammonium bromide, and then add CDs-Eu 3+ The solution is stirred, and then a hexahydrate zinc nitrate solution is added. After stirring, the mixture is allowed to stand, and the mixture is washed with water and dried to obtain the composite material for combining oxytetracycline detection and removal.

3. The method for preparing the composite material with dual-effects of oxytetracycline detection and removal according to claim 2, characterized in that: In step S2, the concentration of the fluorescein ethanol solution is 0.5 mg / mL.

4. The method for preparing the composite material with dual effects of oxytetracycline detection and removal according to claim 2, characterized in that: In step S3, the usage ratio of the citric acid, europium nitrate hexahydrate, urea and formic acid is 2 g:1 g:4 g:20 mL.

5. The method for preparing the composite material with dual effects of oxytetracycline detection and removal according to claim 2, characterized in that: In step S4, the concentration of the aqueous solution containing ZIF-8@LY is 1 mg / mL.

6. The method for preparing the composite material with dual effects of oxytetracycline detection and removal according to claim 2, characterized in that: In step S4, the preparation step of the 2-methylimidazole aqueous solution containing hexadecyltrimethylammonium bromide is as follows: 1.75 mg of hexadecyltrimethylammonium bromide and 565 mg of 2-methylimidazole are added to 8.5 mL of water and stirred evenly.

7. A composite material for detecting and removing oxytetracycline, characterized in that: Prepared according to any one of claims 1 to 6.

8. Use of the composite material for detecting and removing oxytetracycline as claimed in claim 7 in detecting and / or removing oxytetracycline.

9. A sensor for detecting oxytetracycline, characterized in that: The active ingredient of the sensor is the composite material with dual effects of oxytetracycline detection and removal as described in claim 7.

10. A method for detecting oxytetracycline, characterized in that: The composite material for detecting and removing oxytetracycline as claimed in claim 7 is added to the substance to be tested, and the emission spectrum under 410 nm excitation is measured using a fluorescence spectrophotometer.

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