Ciprofloxacin orange carbon dots fluorescent biomimetic sensing material, and preparation method and application thereof

Abstract

The application discloses a kind of ciprofloxacin orange carbon dots fluorescence biomimetic sensing materials and preparation method and application, belong to polymer optical sensing material preparation technical field and antibiotic detection method technical field;The method comprises the following steps: (1) ciprofloxacin solution and methacrylic acid are added to anhydrous ethanol, stirred uniformly, then ethylene glycol dimethyl acrylate and azobisisobutyronitrile are added, nitrogen is removed oxygen, seal, sequentially carry out thermal polymerization, cooling, ultrasonic centrifugation and drying, obtain molecularly imprinted polymer MIPs;(2) by imprinting post-modification strategy, orange carbon dots are mixed with the molecularly imprinted polymer MIPs uniformly, then sequentially carry out ultrasonic centrifugation, drying, obtain ciprofloxacin orange carbon dots fluorescence biomimetic sensing material.The fluorescent material prepared by the method of the application has long-wavelength emission orange carbon dots as fluorescent signal, combined with the imprinting post-modification strategy of molecular imprinting technology, the sensitive detection of ciprofloxacin can be realized;And the preparation method is simple in operation, low in cost, and has good application prospect for the detection of ciprofloxacin in food.

Description

Technical Field

[0001] This invention belongs to the technical field of polymer optical sensing material preparation technology and antibiotic detection method, and particularly relates to a ciprofloxacin orange carbon dot fluorescent biomimetic sensing material, its preparation method and application. Background Technology

[0002] Ciprofloxacin (CIP), a quinolone antibiotic with broad-spectrum antibacterial activity, is widely used in the livestock industry due to its good antibacterial effect, low price, and low toxicity. However, its excessive use increases the possibility of ciprofloxacin residues in animal-derived foods, which can eventually cycle into the human body through the food chain, causing gastrointestinal discomfort, central nervous system disorders, and other serious health risks. Common methods for the quantitative detection of ciprofloxacin include high-performance liquid chromatography (HPLC), liquid chromatography-mass spectrometry (LC-MS), and enzyme-linked immunosorbent assay (ELISA). These methods have drawbacks such as expensive equipment and reagents, long detection times, and lack of portability, limiting their application. In contrast, fluorescence methods are considered a more ideal detection method due to their 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, typically composed of surface groups and a carbonaceous core. As one of the most representative nanoscale materials, carbon dots possess advantages such as low toxicity, good biocompatibility, high stability, and strong resistance to photobleaching. Compared to common blue or green carbon dots, carbon dots exhibiting orange / yellow / red long-wavelength emission can effectively avoid interference from sample and environmental background, improving the accuracy and feasibility of detection. Therefore, long-wavelength luminescent carbon dots are considered outstanding fluorescent signal transduction elements and are widely used in the detection and identification of antibiotics.

[0004] Molecular imprinting (MIT) is a technique that utilizes molecularly imprinted polymers (MIPs) to mimic the interactions between enzymes and substrates or antibodies and antigens, enabling specific recognition of imprinted molecules (also known as template molecules). Compared to traditional imprinting methods, post-imprinting modification strategies use MIPs with template-specific imprinted cavities as carriers. These MIPs are then efficiently encapsulated or grafted to modify the fluorophore, resulting in high-performance fluorescent biomimetic sensors. This strategy not only endows the sensor with excellent specificity and rapid response capabilities by introducing low mass transfer barriers and selective imprinted cavities, but also preserves the inherent fluorescence properties and sensitivity of the fluorophore by effectively avoiding fluorophore loss during synthesis and elution.

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

[0006] To address the aforementioned technical problems, this invention proposes a ciprofloxacin orange carbon dot fluorescent biomimetic sensing material, its preparation method, and its application.

[0007] To achieve the above objectives, the present invention provides the following technical solution:

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

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

[0010] (1) Ciprofloxacin (CIP) solution and methacrylic acid (MAA) were added to anhydrous ethanol and stirred evenly. Then, ethylene glycol dimethacrylate (EGDMA) and azobisisobutyronitrile (AIBN) were added to it. Nitrogen was purged to remove oxygen, and the mixture was sealed. The thermal polymerization reaction was carried out in sequence, cooled, ultrasonically centrifuged and dried to obtain molecularly imprinted polymers (MIPs).

[0011] (2) By using a post-imprinting modification strategy, orange carbon dots (O-CDs) are mixed evenly with the molecularly imprinted polymers (MIPs), and then subjected to ultrasonic centrifugation and drying in sequence to obtain ciprofloxacin orange carbon dot fluorescent biomimetic sensing material.

[0012] Preferably, in step (1), the 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 for the thermal polymerization reaction are: thermal polymerization in a water bath at 65°C for 8-14 hours.

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

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

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

[0017] Using neutral red as the carbon source and ethylene glycol as the solvent, CDs stock solution was obtained through carbon polymerization reaction;

[0018] Acetone, n-hexane, and 5% ethanol were added sequentially to the CDs stock solution to form a mixed system. After standing and separating the layers, the upper layer solution was taken to obtain orange carbon dots (O-CDs).

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

[0020] Furthermore, the conditions during the carbonization polymerization process are: reacting at 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 molecularly imprinted polymers (MIPs) is 4-12 mL: 100 mg.

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

[0024] The second technical solution of this invention:

[0025] A ciprofloxacin orange carbon dot fluorescent biomimetic sensing material was prepared by the above-described method.

[0026] The third technical solution of this invention:

[0027] 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] This invention synthesizes a high-performance fluorescent biomimetic sensing material by employing a post-imprinting modification strategy. The material utilizes a high-affinity biomimetic imprinting material as the recognition element for ciprofloxacin imprinting sites and optically stable orange carbon dots as fluorophores. This material simultaneously retains the sensitivity of the orange carbon dots and the selectivity of the imprinted polymer, exhibiting a fast mass transfer rate and high sensitivity and specificity for the target ciprofloxacin.

[0030] This material is prepared using a chemical synthesis method, which is inexpensive and easy to operate, and is suitable for the detection of ciprofloxacin in food. During the detection process, the synthesized orange carbon dot fluorescent biomimetic sensing material exhibits excellent selectivity and satisfactory anti-interference ability, and can better overcome the problems of complex food matrices and susceptibility to interference in detection. Attached Figure Description

[0031] The accompanying drawings, which form part of this invention, are used to provide a further understanding of the invention. The illustrative embodiments of the invention and their descriptions are used to explain the invention and do not constitute an undue limitation of the invention. In the drawings:

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

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

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

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

[0036] Figure 5 The adsorption kinetic curves of MIPs@O-CDs and NIPs@O-CDs in Example 1 of this invention are shown.

[0037] Figure 6 The above are the response curves of MIPs@O-CDs to different concentrations of CIP in Example 1 of this invention;

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

[0039] Various exemplary embodiments of the present invention will now be described in detail. This detailed description should not be considered as a limitation of the present invention, but rather as a more detailed description of certain aspects, features, and embodiments of the present invention.

[0040] It should be understood that the terminology used in this invention is merely for describing particular embodiments and is not intended to limit the invention. Furthermore, with respect to numerical ranges in this invention, it should be understood that each intermediate value between the upper and lower limits of the range is also specifically disclosed. Every smaller range between any stated value or intermediate value within a stated range, and any other stated value or intermediate value within said range, is also included in this invention. The upper and lower limits of these smaller ranges may be independently included or excluded from the range.

[0041] Unless otherwise stated, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art. While only preferred methods and materials have been described herein, any methods and materials similar or equivalent to those described herein may be used in the implementation or testing of this invention. All references to this specification are incorporated by way of citation to disclose and describe methods and / or materials associated with those references. In the event of any conflict with any incorporated reference, the content of this specification shall prevail.

[0042] Various modifications and variations can be made to the specific embodiments described in this specification without departing from the scope or spirit of the invention, as will be apparent to those skilled in the art. Other embodiments derived from this specification will also be readily apparent to those skilled in the art. This specification and embodiments are merely exemplary.

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

[0044] This invention discloses a method for preparing the above-mentioned orange carbon dot fluorescent biomimetic imprint sensing material, the preparation steps of which are as follows:

[0045] (1) Neutral red was dissolved in ethylene glycol at a ratio of 2g:50mL, and ultrasonic treatment was performed to form a uniform mixture. Then, carbonization polymerization was carried out to obtain CDs stock solution.

[0046] Acetone, n-hexane and 5% ethanol were added to the obtained CDs stock solution to form a mixed system. After standing and separating the layers, the upper layer solution was taken to obtain orange carbon dots (O-CDs). It was then stored in a refrigerator at 4°C in the dark and sealed.

[0047] (2) Disperse the template molecule ciprofloxacin (CIP) in 1 mL of water, and then add it together with methacrylic acid (MAA) into 18 mL of anhydrous ethanol solution. Stir thoroughly to dissolve and disperse evenly. Then add ethylene glycol dimethacrylate (EGDMA) and azobisisobutyronitrile (AIBN), purge with nitrogen to remove oxygen and seal, and thermally polymerize in a water bath at 65°C for 8-14 h.

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

[0049] (3) After the reaction is complete, cool to room temperature, add methanol-glacial acetic acid solution and perform ultrasonic centrifugation to remove template molecules, and dry in an oven at 40°C to obtain molecularly imprinted polymers (MIPs).

[0050] (4) Using a post-imprinting modification strategy, 4-12 mL of orange carbon dots (O-CDs) from step (1) were mixed with 100 mg of molecularly imprinted polymers (MIPs) from step (2) and stirred thoroughly at room temperature. The resulting product was then added to n-hexane and ultrasonically centrifuged to remove unreacted material. The product was then dried in an oven at 40 °C to obtain fluorescent biomimetic imprinted sensing material, which was stored in a desiccator.

[0051] Neutral red, also known as dimethyldiaminophenazine chloride or toluene red, is an acid-base indicator. It is a green crystalline powder that turns red when dissolved in water.

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

[0053] In some preferred embodiments, V in the mixing system of step (1) 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, the mass ratio of template molecule CIP to initiator AIBN in step (2) is 36.78:20-40.

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

[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 hours.

[0058] The ciprofloxacin orange carbon dot fluorescent biomimetic imprint sensing material prepared by the method described in this invention is suitable for the detection of ciprofloxacin in food.

[0059] Unless otherwise specified, "room temperature" in this invention refers to 20-30℃.

[0060] Unless otherwise specified, the term "parts" in this invention refers to parts by weight.

[0061] All raw materials used in this invention were purchased from the market.

[0062] The technical solution of the present invention will be 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 imprint sensing material includes the following steps:

[0065] (1) Dissolve 2g of neutral red in 50mL of ethylene glycol, sonicate to form a homogeneous mixture, and react in a reactor at 200℃ for 4 hours to obtain CDs stock solution; add acetone, n-hexane and 5% ethanol (V) sequentially 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), forming a mixed system, after standing and separating into layers, take the upper layer solution to obtain orange carbon dots (O-CDs), protect from light, seal and store in a refrigerator at 4°C;

[0066] (2) Disperse 36.78 mg of ciprofloxacin (CIP) in 1 mL of water, and then add it together with 0.6 mmol of methacrylic acid (MAA) into 18 mL of anhydrous ethanol solution. Stir thoroughly to dissolve and disperse evenly. Then add 2 mmol of ethylene glycol dimethacrylate (EGDMA) and 30 mg of azobisisobutyronitrile (AIBN), purge with nitrogen for 15 min to remove oxygen and seal. Then heat polymerize in a water bath at 65 °C for 12 h.

[0067] (3) After the reaction is complete, cool to room temperature and add methanol-glacial acetic acid solution (V 甲醇 V 冰醋酸 The template molecules were removed by ultrasonic centrifugation at a ratio of 19:1, and then dried in an oven at 40°C to obtain molecularly imprinted polymers (MIPs).

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

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

[0070] To better understand the performance of the fluorescent biomimetic imprinting sensing material provided by this invention, Fourier transform infrared (FTIR) spectroscopy was performed to characterize the materials O-CDs, MIPs, and NIPs during the synthesis process. Furthermore, MIPs@O-CDs and NIPs@O-CDs were characterized using Fourier transform infrared spectroscopy and scanning electron microscopy (SEM).

[0071] Figure 2 (a) shows the Fourier transform infrared spectrum of O-CDs, with the 3400 cm⁻¹ value in the figure. -1The broad peak at 1088 cm⁻¹ corresponds to OH and NH; -1 The relationship between the position and the CN stretching vibration of O-CDs indicates that the surface of the synthesized O-CDs contains hydroxyl, amino and other groups.

[0072] Figure 2 Middle (b) and Middle (c) 1728cm -1 and 1640cm -1 The characteristic peaks are the stretching vibrations of C=O in MAA and EGDMA and the bending vibrations of C=C in olefin groups; 1155 cm⁻¹ -1 and 1259cm -1 The obvious absorption peak at 3500 cm⁻¹ originates from the COC of the ester in EGDMA; -1 The broad peaks nearby represent the OH stretching vibrations in the polymer. All of these characteristic peaks indicate the presence of MAA and EGDMA, confirming the successful preparation of both molecularly imprinted and non-molecularly imprinted polymers; while Figure 2 (d) and Figure 2 1088cm -1 The emergence of the new absorption band is related to the CN stretching vibration originating from O-CDs, proving the successful introduction of O-CDs and the successful synthesis of carbon dot fluorescent biomimetic sensing material MIPs@O-CD.

[0073] Figure 3 , Figure 4 The images show scanning electron microscope (SEM) images of MIPs@O-CDs and NIPs@O-CDs, respectively. The images show that the synthesized MIPs@O-CDs and NIPs@O-CDs particles are relatively uniform in size, with a particle size of approximately 0.65 μm.

[0074] The following performance verifications were performed on the fluorescent biomimetic imprinting sensing material prepared in Example 1.

[0075] Example 1

[0076] The dynamic adsorption properties of CIP by the fluorescent materials MIPs@O-CDs and NIPs@O-CDs obtained in Example 1 were studied (e.g., Figure 5 (As shown). 200 μL of MIPs@O-CDs (2 mg / mL) was added to 200 μL of LIP standard solution (detection concentration 6 μg / mL). -1 Mix in the mixture. Shake at room temperature for 0-8 minutes, measure the fluorescence intensity using a fluorescence spectrophotometer, and record the fluorescence intensity ratio I. 467 / I 590 Simultaneously, a parallel dynamic adsorption experiment of CIP by NIPs@O-CDs was conducted. Figure 5 As shown, the adsorption of CIP by the material reaches equilibrium in 1.5 min.

[0077] Example 2

[0078] The response of the MIPs@O-CDs fluorescent material prepared in Example 1 to CIP was studied (e.g., Figure 6 (As shown). 200 μL of LMIPs@O-CDs (2 mg / mL) were 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, and 6 μg / mL). -1 The mixture was incubated at room temperature for 1.5 min. The fluorescence spectrum of the mixture was measured in the range of 430–700 nm using 285 nm as the excitation wavelength. The fluorescence intensity ratio was recorded. 467 / I 590 .from Figure 6 As can be seen from the data, with the increase of CIP concentration, the fluorescence intensity is higher than that of I. 467 / I 590 Gradually increase.

[0079] Example 3

[0080] The selectivity of the fluorescent materials MIPs@O-CDs and NIPs@O-CDs obtained in Example 1 for CIP (e.g.) Figure 7 As shown in the image, antibiotics with similar structures and prone to coexistence 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 (each with a detection concentration of 3 μg / mL), respectively. -1 Mix the antibiotics in the mixture and shake at room temperature for 1.5 min. Use a fluorescence spectrophotometer to detect the ratio of fluorescence intensity before and after adsorption of the antibiotics on the fluorescent material. 467 / I 590 Record the changes.

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

[0082] Example 2

[0083] (1) Dissolve 2g of neutral red in 50mL of ethylene glycol, sonicate to form a homogeneous mixture, and react in a reactor at 200℃ for 4 hours to obtain CDs stock solution; add acetone, n-hexane and 5% ethanol (V) sequentially 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), forming a mixed system, after standing and separating into layers, take the upper layer solution to obtain orange carbon dots (O-CDs), protect from light, seal and store in a refrigerator at 4°C;

[0084] (2) Disperse 36.78 mg of ciprofloxacin (CIP) in 1 mL of water, and then add it together with 0.4 mmol of methacrylic acid to 18 mL of anhydrous ethanol solution. Stir thoroughly to dissolve and disperse evenly. Then add 1.5 mmol of ethylene glycol dimethacrylate (EGDMA) and 20 mg of azobisisobutyronitrile (AIBN). Purge with nitrogen for 15 min to remove oxygen and seal. Perform thermal polymerization in a water bath at 65 °C for 8 h.

[0085] (3) After the reaction is complete, cool to room temperature, add methanol-glacial acetic acid solution (V methanol:V glacial acetic acid = 19:1) and perform ultrasonic centrifugation to remove template molecules. Dry in an oven at 40°C to obtain molecularly imprinted polymers (MIPs).

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

[0087] The performance testing of the fluorescent biomimetic imprint sensing material obtained in this embodiment can be performed according to the methods of Example 1-Example 3.

[0088] Example 3

[0089] (1) Dissolve 2g of neutral red in 50mL of ethylene glycol, sonicate to form a homogeneous mixture, and react in a reactor at 200℃ for 4 hours to obtain the CDs stock solution. The obtained CDs stock solution is then sequentially added with 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), forming a mixed system, after standing and separating into layers, take the upper layer solution to obtain orange carbon dots (O-CDs), protect from light, seal and store in a refrigerator at 4°C;

[0090] (2) Disperse 36.78 mg of ciprofloxacin (CIP) in 1 mL of water, and then add it together with 1 mmol of methacrylic acid to 18 mL of anhydrous ethanol solution. Stir thoroughly to dissolve and disperse evenly. Then add 3 mmol of ethylene glycol dimethacrylate (EGDMA) and 40 mg of azobisisobutyronitrile (AIBN), purge with nitrogen for 15 min to remove oxygen and seal. Then heat polymerize in a water bath at 65 °C for 14 h.

[0091] (3) After the reaction is complete, cool to room temperature, add methanol-glacial acetic acid solution (V methanol:V glacial acetic acid = 19:1) and perform ultrasonic centrifugation to remove template molecules. Dry in an oven at 40°C to obtain molecularly imprinted polymers (MIPs).

[0092] (4) Using a post-imprinting modification strategy, 12 mL of orange carbon dots (O-CDs) from step 1 were mixed with 100 mg of molecularly imprinted polymers (MIPs) and stirred thoroughly at room temperature for 12 h. The resulting product was then added to n-hexane and ultrasonically centrifuged to remove unreacted material. The product was then dried in an oven at 40 °C to obtain fluorescent biomimetic imprinted sensing material MIPs@O-CDs, which was stored in a desiccator.

[0093] The performance testing of the fluorescent biomimetic imprint sensing material obtained in this embodiment can be performed according to the methods of Example 1-Example 3.

[0094] In summary, this invention employs a simple and effective post-imprinting modification strategy to meticulously design and construct a fluorescent biomimetic imprinting sensing material for ciprofloxacin detection. In this strategy, the high-affinity imprinted polymer endows the sensor with superior selectivity. Compared to blue-green carbon dots, long-wavelength emitting orange carbon dots exhibit superior optical properties, resulting in higher sensitivity and resistance to background interference during detection. Furthermore, post-modification of the fluorophore better avoids fluorophore loss during target elution. Therefore, the ciprofloxacin orange carbon dot fluorescent biomimetic sensing material prepared by the method of this invention possesses advantages such as fast mass transfer rate, high detection sensitivity, and good specificity in ciprofloxacin detection.

[0095] The above are merely preferred embodiments of the present invention, but the scope of protection of the present invention is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the scope of the technology disclosed in the present invention should be included within the scope of protection of the present invention. Therefore, the scope of protection of the present invention should be determined by the scope of the claims.

Claims

1. A method for preparing a ciprofloxacin orange carbon dot fluorescent biomimetic sensing material, characterized in that, Includes the following steps: (1) Ciprofloxacin solution and methacrylic acid were added together to anhydrous ethanol and stirred evenly. Then ethylene glycol dimethacrylate and azobisisobutyronitrile were added to it. Nitrogen was purged to remove oxygen, and the mixture was sealed. The thermal polymerization reaction was carried out in sequence, cooled, ultrasonically centrifuged and dried to obtain molecularly imprinted polymers (MIPs). (2) By using the imprinting modification strategy, the orange carbon dots are mixed evenly with the molecularly imprinted polymers (MIPs), and then subjected to ultrasonic centrifugation and drying in sequence to obtain the ciprofloxacin orange carbon dot fluorescent biomimetic sensing material. The solvent added during the ultrasonic centrifugation process 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; In step (2), the preparation process of the orange carbon dots is as follows: Using neutral red as the carbon source and ethylene glycol as the solvent, CDs stock solution was obtained through carbon polymerization reaction; Acetone, n-hexane, and ethanol were added sequentially to the CDs stock solution to form a mixed system. After standing and separating the layers, the upper layer solution was taken to obtain orange carbon dots.

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 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 for the thermal polymerization reaction are: thermal polymerization in a 65°C water bath for 8-14 hours; and / or The drying conditions are as follows: drying in an oven at 40°C for 12 hours.

4. The method for preparing a ciprofloxacin orange carbon dot fluorescent biomimetic sensing material according to claim 1, characterized in that, The ratio of neutral red to ethylene glycol is 2g:50mL.

5. The method for preparing a ciprofloxacin orange carbon dot fluorescent biomimetic sensing material according to claim 1, characterized in that, The conditions for the carbonization polymerization reaction are: reaction at 200℃ for 4 hours.

6. 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 molecularly imprinted polymers (MIPs) is 4-12 mL: 100 mg.

7. A ciprofloxacin orange carbon dot fluorescent biomimetic sensing material, characterized in that, It is prepared according to any one of claims 1-6.

8. The application of the ciprofloxacin orange carbon dot fluorescent biomimetic sensing material as described in claim 7 in the field of food antibiotic detection.

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