Ciprofloxacin orange carbon dot fluorescent bionic sensing material as well as preparation method and application thereof

Abstract

The invention discloses a ciprofloxacin orange carbon dot fluorescent bionic sensing material as well as a preparation method and an application thereof, and belongs to the technical fields of a preparation technology of a macromolecular optical sensing material and an antibiotic detection method. The method comprises the following steps: (1) jointly adding a ciprofloxacin solution and methacrylic acid into absolute ethyl alcohol, uniformly stirring, adding ethylene glycol dimethacrylate and azodiisobutyronitrile, introducing nitrogen to remove oxygen, sealing, and sequentially performing thermal polymerization reaction, cooling, ultrasonic centrifugation and drying to obtain a molecularly imprinted polymer MIPs; and (2) uniformly mixing orange carbon dots with the molecularly imprinted polymer MIPs through a post-imprinting modification strategy, and sequentially carrying out ultrasonic centrifugation and drying to obtain the ciprofloxacin orange carbon dot fluorescent bionic sensing material. The fluorescent material prepared by the method provided by the invention takes the orange carbon dots with long-wavelength emission as a fluorescence signal, and can realize sensitive detection of ciprofloxacin by combining with a post-imprinting modification strategy of a molecular imprinting technology; and the preparation method is simple to operate and low in cost, and has a good application prospect in detection of ciprofloxacin in food.

Description

Technical Field

[0001] The invention belongs to the technical fields of polymer optical sensing material preparation technology and antibiotic detection method, and in particular relates to a ciprofloxacin orange carbon dot fluorescent bionic sensing material and a preparation method and application thereof. Background Art

[0002] Ciprofloxacin (CIP), as a quinolone antibiotic with broad-spectrum antibacterial activity, is often used in the animal husbandry industry due to its good antibacterial effect, low price, and low toxicity. However, its excessive use leads to an increase in the possibility of ciprofloxacin residues in animal-derived foods, and eventually circulates to the human body through the food chain, causing human gastrointestinal discomfort, central nervous system disorders, etc., seriously endangering human health. Commonly used methods for the quantitative detection of ciprofloxacin include high-performance liquid chromatography, liquid chromatography-mass spectrometry, enzyme-linked immunosorbent assay, etc. These methods have the disadvantages of expensive equipment and reagents, long detection time, lack of portability, etc., and have limitations in use. Fluorescence method is regarded as a more ideal detection method because of its advantages of high sensitivity, fast detection speed, and low cost.

[0003] Carbon dots (CDs), also known as "carbon quantum dots", are a general term for a class of zero-dimensional carbon nanomaterials with fluorescent properties, usually composed of two parts: surface groups and carbonaceous cores. As one of the most representative nano-sized materials, carbon dots have the advantages of low toxicity, good biocompatibility, high stability, and strong resistance to photobleaching. Compared with common blue or green carbon dots, carbon dots with orange / yellow / red long-wave emission can effectively avoid interference from samples and environmental backgrounds, and improve the accuracy and feasibility of detection. Therefore, long-wavelength luminescent carbon dots are considered to be outstanding fluorescent signal transduction elements and are widely used in the field of antibiotic detection and identification.

[0004] Molecular imprinting technology (MIT) is a technology that uses molecular imprinting polymers (MIPs) to simulate the interaction between enzymes and substrates or antibodies and antigens to specifically identify imprinted molecules (also called template molecules). Compared with traditional imprinting methods, the post-imprinting modification strategy uses MIPs with template-specific imprinting cavities as carriers, and modifies them with fluorophores through efficient encapsulation or grafting to obtain high-performance fluorescent biomimetic sensors. This strategy not only gives the sensor good specificity and rapid response capabilities by introducing low mass transfer barriers and selective imprinting cavities, but also retains the inherent fluorescence properties and sensitivity of the fluorophore by effectively avoiding the loss of the fluorophore during synthesis and elution.

[0005] The present invention combines orange carbon dots with excellent fluorescence properties with highly selective molecular imprinted polymers, and prepares a fluorescent biomimetic imprinted sensing material with fast detection speed and high sensitivity through a post-imprinting modification strategy, thereby realizing the detection of ciprofloxacin in food. Summary of the invention

[0006] In view of the above technical problems, the present invention proposes a ciprofloxacin orange carbon dot fluorescent bionic sensing material and a preparation method and application thereof.

[0007] To achieve the above object, the present invention provides the following technical solutions:

[0008] One of the technical solutions of the present invention:

[0009] A method for preparing a ciprofloxacin orange carbon dot fluorescent biomimetic sensing material comprises the following steps:

[0010] (1) adding ciprofloxacin (CIP) solution and methacrylic acid (MAA) into anhydrous ethanol, stirring evenly, then adding ethylene glycol dimethacrylate (EGDMA) and azobisisobutyronitrile (AIBN), passing nitrogen to deoxygenate, sealing, sequentially performing thermal polymerization, cooling, ultrasonic centrifugation and drying to obtain molecularly imprinted polymers MIPs;

[0011] (2) Through the post-imprinting modification strategy, the orange carbon dots (O-CDs) and the molecular imprinting polymer MIPs are evenly mixed, and then ultrasonic centrifugation and drying are performed in sequence to obtain the ciprofloxacin orange carbon dot fluorescent biomimetic sensing material.

[0012] Preferably, in step (1), the usage ratio of ciprofloxacin, methacrylic acid, ethylene glycol dimethacrylate and azobisisobutyronitrile in the ciprofloxacin solution is 36.78 mg: 0.4-1 mmol: 1.5-3 mmol: 20-40 mg.

[0013] Preferably, in step (1), the conditions of the thermal polymerization reaction are: thermal polymerization in a 65° C. water bath for 8-14 h.

[0014] Preferably, in step (1), the conditions during the drying process are: drying in an oven at 40° C. for 12 hours.

[0015] Preferably, the solvent added in the ultrasonic centrifugation in step (1) is a methanol-glacial acetic acid solution, and the volume ratio of the two is: V 甲醇 :V 冰醋酸 =19∶1.

[0016] Preferably, in step (2), the preparation process of the orange carbon dots is:

[0017] Neutral red was used as a carbon source and ethylene glycol was used as a solvent to obtain a CDs stock solution through carbonization polymerization.

[0018] Acetone, n-hexane and 5% ethanol were added to the CDs stock solution in sequence to form a mixed system, and then the upper layer solution was collected after standing for stratification to obtain orange carbon dots (O-CDs).

[0019] Furthermore, the usage ratio of the neutral red and ethylene glycol is 2g:50mL.

[0020] Furthermore, the conditions during the carbonization polymerization reaction are: reacting at a temperature of 200° C. for 4 hours.

[0021] Furthermore, in the mixed system, the volume ratio of CDs stock solution, acetone, n-hexane and 5% ethanol is 1:5:1:1.

[0022] Preferably, in step (2), the ratio of the orange carbon dots to the molecular imprinting polymers MIPs is 4-12 mL: 100 mg.

[0023] Preferably, in step (2), the solvent added by ultrasonic centrifugation is n-hexane.

[0024] The second technical solution of the present invention:

[0025] A ciprofloxacin orange carbon dot fluorescent bionic sensing material is prepared by the above preparation method.

[0026] The third technical solution of the present invention:

[0027] The application of the ciprofloxacin orange carbon dot fluorescent bionic sensing material in the field of food antibiotic detection.

[0028] Compared with the prior art, the present invention has the following advantages and technical effects:

[0029] The present invention adopts a post-imprinting modification strategy, uses a high-affinity biomimetic imprinting material as a recognition element of the ciprofloxacin imprinting site, and uses an optically stable orange carbon dot as a fluorophore to synthesize a fluorescent biomimetic sensing material with excellent performance. The material retains the sensitivity of the orange carbon dot and the selectivity of the imprinting polymer, has a fast mass transfer rate, and has high-sensitivity recognition and specific selectivity for the target ciprofloxacin.

[0030] The material is prepared by chemical synthesis method, which is low-cost, easy to operate, and suitable for the detection of ciprofloxacin in food. During the detection process, the synthesized orange carbon dot fluorescent bionic sensing material showed excellent selectivity and satisfactory anti-interference ability, which can better overcome the problems of complex food matrix and susceptibility to interference in detection. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] The accompanying drawings constituting a part of the present invention are used to provide a further understanding of the present invention. The exemplary embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute an improper limitation of the present invention. In the accompanying drawings:

[0032] Figure 1This is a schematic diagram of the preparation of the sensing material in Example 1 of the present invention;

[0033] Figure 2 : It is the Fourier transform infrared spectra of O-CDs, MIPs, NIPs, MIPs@O-CDs and NIPs@O-CDs in Example 1 of the present invention;

[0034] Figure 3 is a scanning electron microscope image of MIPs@O-CDs in Example 1 of the present invention;

[0035] Figure 4 is a scanning electron microscope image of NIPs@O-CDs in Example 1 of the present invention;

[0036] Figure 5 1 is the adsorption kinetic curve of MIPs@O-CDs and NIPs@O-CDs in Example 1 of the present invention;

[0037] Figure 6 Response curve of MIPs@O-CDs to different concentrations of CIP in Example 1 of the present invention;

[0038] Figure 7 This is the adsorption specificity diagram of MIPs@O-CDs and NIPs@O-CDs in Example 1 of the present invention. DETAILED DESCRIPTION

[0039] 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 should be understood as a more detailed description of certain aspects, features, and embodiments of the present invention.

[0040] It should be understood that the terms described in the present invention are only for describing special embodiments and are not intended to limit the present invention. In addition, for the numerical range in the present invention, it should be understood that each intermediate value between the upper and lower limits of the scope is also specifically disclosed. Each smaller range between the intermediate value in any stated value or stated range and any other stated value or intermediate value in the described range is also included in the present invention. The upper and lower limits of these smaller ranges can be independently included or excluded in the scope.

[0041] Unless otherwise indicated, all technical and scientific terms used herein have the same meanings as those generally understood by those skilled in the art. Although the present invention describes only preferred methods and materials, any methods and materials similar or equivalent to those described herein may also be used in the implementation or testing of the present invention. All documents mentioned in this specification are incorporated by reference to disclose and describe the methods and / or materials associated with the documents. In the event of a conflict with any incorporated document, the content of this specification shall prevail.

[0042] It will be apparent to those skilled in the art that various modifications and variations may be made to the specific embodiments of the present invention description without departing from the scope or spirit of the present invention. Other embodiments derived from the present invention description will be apparent to those skilled in the art. The present invention description and examples are exemplary only.

[0043] The words “include,” “including,” “have,” “contain,” etc. used in this document are open-ended terms, meaning including but not limited to.

[0044] The present invention discloses a method for preparing the above-mentioned orange carbon dot fluorescent biomimetic imprinting sensing material, and the preparation steps are as follows:

[0045] (1) dissolving neutral red in ethylene glycol at a ratio of 2 g to 50 mL, subjecting the mixture to ultrasonic treatment to form a uniform mixed solution, and then subjecting the mixture to carbonization polymerization to obtain a CDs stock solution;

[0046] Acetone, n-hexane and 5% ethanol were added to the obtained CDs stock solution in sequence to form a mixed system. After standing for stratification, the upper layer solution was taken to obtain orange carbon dots (O-CDs), which were sealed and stored in a refrigerator at 4°C away from light.

[0047] (2) The template molecule ciprofloxacin (CIP) was dispersed in 1 mL of water, and then added together with methacrylic acid (MAA) into 18 mL of anhydrous ethanol solution, and stirred thoroughly to dissolve and disperse evenly; then ethylene glycol dimethacrylate (EGDMA) and azobisisobutyronitrile (AIBN) were added, nitrogen was passed to remove oxygen, and the mixture was sealed, and thermally polymerized in a 65°C water bath for 8-14 hours;

[0048] Among them, methacrylic acid 0.4-1mmol, ethylene glycol dimethacrylate 1.5-3mmol, azobisisobutyronitrile 20-40mg;

[0049] (3) After the reaction is completed, the mixture is cooled to room temperature, a methanol-glacial acetic acid solution is added for ultrasonic centrifugation, the template molecules are eluted and removed, and the mixture is dried in an oven at 40°C to obtain molecularly imprinted polymers (MIPs);

[0050] (4) Through the post-imprinting modification strategy, 4-12 mL of orange carbon dots (O-CDs) in step (1) and 100 mg of molecular imprinting polymer MIPs in step (2) were mixed and stirred at room temperature; the obtained product was added with n-hexane for ultrasonic centrifugation to remove unreacted products, and dried in an oven at 40°C to obtain a fluorescent biomimetic imprinted sensing material, which was stored in a desiccator.

[0051] Among them, neutral red, also known as dimethyldiaminophenazine chloride and toluene red, is an acid-base indicator, a green crystalline powder, which turns red when dissolved in water.

[0052] In some preferred embodiments, the carbonization polymerization reaction in step (1) is carried out at a temperature of 200° C. for 4 hours.

[0053] In some preferred embodiments, in step (1), V 原液 :V 丙酮 =1∶5, V 原液 :V 正己烷 =1∶1, V 原液 :V 5％乙醇 =1∶1.

[0054] In some preferred embodiments, in step (2), the mass ratio of the template molecule CIP to the initiator AIBN is 36.78:20-40.

[0055] In some preferred embodiments, the nitrogen gas flow time in step (2) is 15 minutes.

[0056] In some preferred embodiments, the methanol-glacial acetic acid solution in step (3) is a mixed eluent with a volume ratio of 19:1, and the molecularly imprinted polymer is eluted multiple times until no ciprofloxacin is detected in the eluent.

[0057] In some preferred embodiments, the stirring time at room temperature in step (4) is 12 h.

[0058] The ciprofloxacin orange carbon dot fluorescent biomimetic imprinting sensing material prepared by the method of the present invention is suitable for detecting ciprofloxacin in food.

[0059] The "room temperature" in the present invention refers to 20-30°C unless otherwise specified.

[0060] The "parts" described in the present invention, unless otherwise specified, refer to parts by mass.

[0061] The raw materials used in the present invention are all purchased from the market.

[0062] The technical solution of the present invention is further illustrated by the following embodiments.

[0063] Example 1

[0064] like Figure 1 As shown, a method for preparing a ciprofloxacin orange carbon dot fluorescent biomimetic imprinting sensing material comprises the following steps:

[0065] (1) Dissolve 2 g of neutral red in 50 mL of ethylene glycol, treat with ultrasound to form a uniform mixture, and react in a reactor at 200° C. for 4 hours to obtain a CDs stock solution; acetone, n-hexane, and 5% ethanol (V ) were added to the obtained CDs stock solution. 原液 :V 丙酮 =1:5, V 原液 :V 正己烷 =1:1, V 原液 :V 5％乙醇 =1:1) to form a mixed system, and after standing for stratification, the upper layer solution was taken to obtain orange carbon dots (O-CDs), which were sealed and stored in a refrigerator at 4°C away from light;

[0066] (2) 36.78 mg of ciprofloxacin (CIP) was dispersed in 1 mL of water, and then added together with 0.6 mmol of methacrylic acid (MAA) into 18 mL of anhydrous ethanol solution, stirred thoroughly to dissolve and disperse evenly, and then 2 mmol of ethylene glycol dimethacrylate (EGDMA) and 30 mg of azobisisobutyronitrile (AIBN) were added, nitrogen was passed through for 15 min to remove oxygen, and the mixture was sealed and thermally polymerized in a 65°C water bath for 12 h;

[0067] (3) After the reaction was completed, the mixture was cooled to room temperature and methanol-glacial acetic acid solution (V 甲醇 :V 冰醋酸 =19:1) to perform ultrasonic centrifugation, elute and remove the template molecules, and dry in an oven at 40°C to obtain molecularly imprinted polymers MIPs;

[0068] (4) Through the post-imprinting modification strategy, 10 mL of orange carbon dots (O-CDs) was mixed with 100 mg of molecular imprinted polymers (MIPs) and stirred at room temperature for 12 h. The resulting product was added with n-hexane for ultrasonic centrifugation to remove the unreacted product and dried in an oven at 40 °C to obtain the fluorescent biomimetic imprinted sensing material MIPs@O-CDs, which was stored in a desiccator.

[0069] In addition, fluorescent biomimetic non-imprinting sensing materials (NIPs@O-CDs) were prepared according to the above method but without adding the template molecule CIP.

[0070] In order to better understand the performance of the fluorescent biomimetic imprinted sensing material provided by the present invention, the materials O-CDs, MIPs, and NIPs in the synthesis process were characterized by Fourier infrared spectroscopy. MIPs@O-CDs and NIPs@O-CDs were characterized by Fourier infrared spectroscopy and scanning electron microscopy (SEM).

[0071] Figure 2 (a) is the Fourier infrared spectrum of O-CDs, 3400 cm -1The broad vibration peak at 1088cm -1 The positions are related to the CN stretching vibration of O-CDs, indicating that the synthesized O-CDs contain hydroxyl, amino and other groups on their surfaces.

[0072] Figure 2 Middle (b) and 2 middle (c) 1728cm -1 and 1640cm -1 The characteristic peaks are the stretching vibration of C=O in MAA and EGDMA and the bending vibration of C=C in the olefin group; 1155cm -1 and 1259cm -1 The obvious absorption peak at 3500cm comes from the COC of ester in EGDMA; -1 The broad peak near is the OH stretching vibration in the polymer. The above characteristic peaks all indicate the presence of MAA and EGDMA, confirming the successful preparation of molecularly imprinted polymers and non-molecularly imprinted polymers; Figure 2 Middle (d) and Figure 2 Middle (e) 1088cm -1 The emergence of the new absorption band is related to the CN stretching vibration originating from O-CDs, which proves the successful introduction of O-CDs and the successful synthesis of carbon dot fluorescent bionic sensing material MIPs@O-CD.

[0073] Figure 3 , Figure 4 The following are the scanning electron micrographs of MIPs@O-CDs and NIPs@O-CDs. It can be seen from the figure that the synthesized MIPs@O-CDs and NIPs@O-CDs have a relatively uniform particle size of about 0.65 μm.

[0074] The following effects were verified on the fluorescent biomimetic imprinted sensing material prepared in Example 1:

[0075] Effect Example 1

[0076] The dynamic adsorption performance of the fluorescent materials MIPs@O-CDs and NIPs@O-CDs obtained in Example 1 on CIP (such as Figure 5 200 μL of MIPs@O-CDs (2 mg / mL) was added to 200 μL of CIP standard solution (detection concentration was 6 μg mL -1 ) and mixed. The mixture was shaken at room temperature for 0-8 min, and the fluorescence intensity was measured by a fluorescence spectrophotometer, and the fluorescence intensity ratio was recorded. 467 / I 590 At the same time, the dynamic adsorption experiment of NIPs@O-CDs on CIP was carried out in parallel. Figure 5 As shown, the adsorption of CIP by the material reached equilibrium in 1.5 min.

[0077] Effect Example 2

[0078] The response of the MIPs@O-CDs fluorescent material prepared in Example 1 to CIP (such as Figure 6 200 μL of MIPs@O-CDs (2 mg / mL) was mixed with 200 μL of CIP standard solution (after mixing, the detection concentrations of CIP were 0.025, 0.05, 0.25, 0.5, 0.75, 1, 1.25, 1.5, 2, 2.5, 3, 3.5, 4, 4.5, 5, 5.5, 6 μg mL -1 ) and incubate at room temperature for 1.5 min. The fluorescence spectrum of the mixture was measured in the range of 430-700 nm with an excitation wavelength of 285 nm. The fluorescence intensity ratio I 467 / I 590 .from Figure 6 As can be seen from the figure, with the increase of CIP concentration, the fluorescence intensity is 467 / I 590 Gradually increase.

[0079] Effect Example 3

[0080] The selectivity of the fluorescent materials MIPs@O-CDs and NIPs@O-CDs obtained in Example 1 to CIP (such as Figure 7 As shown in the figure, antibiotics with similar structures and easy to coexist in samples such as norfloxacin (NOR), doxycycline (DOX), kanamycin (KAN), and chloramphenicol (CPL) were selected. 200 μL of MIPs@O-CDs (2 mg / mL) and NIPs@O-CDs (2 mg / mL) were added to 200 μL of ciprofloxacin, doxycycline, kanamycin, and chloramphenicol standard solutions (the detection concentrations were all 3 μg / mL). -1 ) and shaken at room temperature for 1.5 min. The fluorescence intensity ratio of the fluorescent material before and after adsorption of the above antibiotics was detected by a fluorescence spectrophotometer. 467 / I 590 and record the changes.

[0081] like Figure 7 As shown in the figure, the effect of CIP on MIPs@O-CDs is more significant, which is attributed to the fact that CIP acts as a template in the imprinting process. After elution, there are imprinting pores on the surface of the molecularly imprinted polymer that match CIP in size, structure and functional groups, which have a selective recognition effect on CIP.

[0082] Example 2

[0083] (1) Dissolve 2 g of neutral red in 50 mL of ethylene glycol, treat with ultrasound to form a uniform mixture, and react in a reactor at 200° C. for 4 hours to obtain a CDs stock solution; acetone, n-hexane, and 5% ethanol (V ) were added to the obtained CDs stock solution. 原液 :V 丙酮 =1:5, V 原液 :V 正己烷 =1:1, V 原液 :V 5％乙醇 =1:1) to form a mixed system, and after standing for stratification, the upper layer solution was taken to obtain orange carbon dots (O-CDs), which were sealed and stored in a refrigerator at 4°C away from light;

[0084] (2) 36.78 mg of ciprofloxacin (CIP) was dispersed in 1 mL of water, and then added together with 0.4 mmol of methacrylic acid into 18 mL of anhydrous ethanol solution, and stirred thoroughly to dissolve and disperse evenly. Then, 1.5 mmol of ethylene glycol dimethacrylate (EGDMA) and 20 mg of azobisisobutyronitrile (AIBN) were added, and nitrogen was passed through for 15 min to remove oxygen, and the mixture was sealed and thermally polymerized in a 65°C water bath for 8 h.

[0085] (3) After the reaction, the mixture was cooled to room temperature, and a methanol-glacial acetic acid solution (V methanol: V acetic acid = 19:1) was added for ultrasonic centrifugation to elute and remove the template molecules, and the mixture was dried in an oven at 40°C to obtain molecularly imprinted polymers (MIPs);

[0086] (4) Through the post-imprinting modification strategy, 4 mL of orange carbon dots (O-CDs) were mixed with 100 mg of molecular imprinting polymers (MIPs) and stirred thoroughly at room temperature for 12 h; the resulting product was added with n-hexane for ultrasonic centrifugation to remove the unreacted products and dried in an oven at 40 °C to obtain the fluorescent biomimetic imprinting sensing material MIPs@O-CDs, which was stored in a desiccator.

[0087] The performance test of the fluorescent biomimetic imprinted sensing material obtained in this example can be carried out according to the methods of Effect Examples 1 to 3.

[0088] Example 3

[0089] (1) Dissolve 2 g of neutral red in 50 mL of ethylene glycol, treat with ultrasound to form a uniform mixture, and react in a reactor at 200° C. for 4 hours to obtain a CDs stock solution. Acetone, n-hexane, and 5% ethanol (V 原液 :V 丙酮 =1:5, V 原液 :V 正己烷 =1:1, V 原液 :V 5％乙醇=1:1) to form a mixed system, and after standing for stratification, the upper layer solution was taken to obtain orange carbon dots (O-CDs), which were sealed and stored in a refrigerator at 4°C away from light;

[0090] (2) 36.78 mg of ciprofloxacin (CIP) was dispersed in 1 mL of water, and then added together with 1 mmol of methacrylic acid into 18 mL of anhydrous ethanol solution, stirred thoroughly to dissolve and disperse evenly, and then 3 mmol of ethylene glycol dimethacrylate (EGDMA) and 40 mg of azobisisobutyronitrile (AIBN) were added, nitrogen was passed through for 15 min to remove oxygen, and the mixture was sealed and thermally polymerized in a 65°C water bath for 14 h;

[0091] (3) After the reaction, the mixture was cooled to room temperature, and a methanol-glacial acetic acid solution (V methanol: V acetic acid = 19:1) was added for ultrasonic centrifugation to elute and remove the template molecules, and the mixture was dried in an oven at 40°C to obtain molecularly imprinted polymers (MIPs);

[0092] (4) Through the post-imprinting modification strategy, 12 mL of orange carbon dots (O-CDs) in step 1 was mixed with 100 mg of molecular imprinting polymer (MIPs) and stirred at room temperature for 12 h; the resulting product was added with n-hexane for ultrasonic centrifugation to remove the unreacted products, and dried in an oven at 40°C to obtain the fluorescent biomimetic imprinting sensing material MIPs@O-CDs, which was stored in a desiccator.

[0093] The performance test of the fluorescent biomimetic imprinted sensing material obtained in this example can be carried out according to the methods of Effect Examples 1 to 3.

[0094] In summary, the present invention adopts a simple and effective imprinting post-modification strategy to carefully design and construct a fluorescent biomimetic imprinted sensing material for ciprofloxacin detection. In this strategy, the high-affinity imprinted polymer gives the sensor superior selectivity. Compared with blue-green carbon dots, the long-wavelength emission orange carbon dots have excellent optical properties and have high sensitivity and anti-background interference ability during detection. At the same time, the post-modification of the fluorophore better avoids the loss of the fluorophore during the elution of the target. Therefore, the ciprofloxacin orange carbon dot fluorescent biomimetic sensing material prepared by the preparation method of the present invention has the advantages of fast mass transfer rate, high detection sensitivity, good specificity, etc. during ciprofloxacin detection.

[0095] The above are only preferred specific embodiments of the present invention, but the protection scope of the present invention is not limited thereto. Any changes or substitutions that can be easily thought of by a person skilled in the art within the technical scope disclosed by the present invention should be included in the protection scope of the present invention. Therefore, the protection scope of the present invention should be based on the protection scope of the claims.

Claims

1. A method for preparing a ciprofloxacin orange carbon dot fluorescent biomimetic sensing material, characterized in that: The following steps are involved: (1) adding ciprofloxacin solution and methacrylic acid to anhydrous ethanol, stirring evenly, then adding ethylene glycol dimethacrylate and azobisisobutyronitrile, passing nitrogen to deoxygenate, sealing, sequentially performing thermal polymerization, cooling, ultrasonic centrifugation and drying to obtain molecularly imprinted polymers MIPs; (2) Through the post-imprinting modification strategy, the orange carbon dots and the molecular imprinting polymer MIPs are evenly mixed, and then ultrasonic centrifugation and drying are performed in sequence to obtain the ciprofloxacin orange carbon dot fluorescent biomimetic sensing material.

2. The method for preparing a ciprofloxacin orange carbon dot fluorescent biomimetic sensing material according to claim 1, characterized in that: In step (1), the dosage ratio of ciprofloxacin to methacrylic acid, ethylene glycol dimethacrylate and azobisisobutyronitrile in the ciprofloxacin solution is 36.78 mg: 0.4-1 mmol: 1.5-3 mmol: 20-40 mg.

3. The method for preparing a ciprofloxacin orange carbon dot fluorescent biomimetic sensing material according to claim 1, characterized in that: In step (1), the conditions of the thermal polymerization reaction are: thermal polymerization in a water bath at 65° C. for 8-14 hours; and / or The conditions in the drying process are: drying in an oven at 40° C. for 12 h.

4. The method for preparing a ciprofloxacin orange carbon dot fluorescent biomimetic sensing material according to claim 1, characterized in that: The solvent added during the ultrasonic centrifugation in step (1) is a methanol-glacial acetic acid solution, and the volume ratio of the two is: V 甲醇 :V 冰醋酸 =19∶1.

5. The method for preparing a ciprofloxacin orange carbon dot fluorescent biomimetic sensing material according to claim 1, characterized in that: In step (2), the preparation process of the orange carbon dots is as follows: Neutral red was used as a carbon source and ethylene glycol was used as a solvent to obtain CDs stock solution through carbonization polymerization reaction; Acetone, n-hexane and ethanol were added to the CDs stock solution in sequence to form a mixed system, and then the upper layer solution was collected after standing to separate the layers, thereby obtaining orange carbon dots.

6. The method for preparing a ciprofloxacin orange carbon dot fluorescent biomimetic sensing material according to claim 5, characterized in that: The usage ratio of the neutral red to ethylene glycol is 2 g:50 mL.

7. The method for preparing a ciprofloxacin orange carbon dot fluorescent biomimetic sensing material according to claim 5, characterized in that: The conditions during the carbonization polymerization reaction are: reacting at a temperature of 200° C. for 4 hours.

8. The method for preparing a ciprofloxacin orange carbon dot fluorescent biomimetic sensing material according to claim 1, characterized in that: In step (2), the ratio of the orange carbon dots to the molecular imprinting polymer MIPs is 4-12 mL: 100 mg.

9. A ciprofloxacin orange carbon dot fluorescent biomimetic sensing material, characterized in that: Prepared according to the preparation method according to any one of claims 1 to 8.

10. Use of the ciprofloxacin orange carbon dot fluorescent bionic sensing material as claimed in claim 9 in the field of food antibiotic detection.

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