Fluoroquinolone antibiotic-enriched nanomaterials, methods of making and using the same

Abstract

This invention discloses nanomaterials for enriching fluoroquinolone antibiotics, their preparation methods, and applications. The nanomaterials comprise a core of magnetite nanoparticles and a porous mesh-like shell; the shell covers at least a portion of the surface of the core. The preparation method involves contacting magnetic magnetite nanoparticles with 2,4,6-tris(4-aminophenyl)-1,3,5-triazine and ultrasonically treating the mixture, followed by stirring. The resulting mixture is then mixed with 2,4,6-trihydroxybenzene-1,3,5-tricarboxaldehyde and a catalyst, and stirred to obtain the aforementioned nanomaterials. The nanomaterials of this invention possess advantages such as high-efficiency adsorption and rapid equilibrium, stability and reusability, selective enrichment, and wide applicability. Furthermore, the preparation process is mild, and the magnetic separation operation is simple.

Description

Technical Field

[0001] This invention belongs to the field of analytical chemistry technology, and specifically relates to nanomaterials for enriching fluoroquinolone antibiotics, their preparation methods, and applications. Background Technology

[0002] Fluoroquinolone antibiotics are a class of synthetic broad-spectrum antibacterial drugs that exert potent bactericidal effects by inhibiting bacterial DNA gyrase and topoisomerase IV, thus interfering with bacterial DNA replication and repair. Due to their broad antibacterial spectrum, strong antibacterial activity, and lack of cross-resistance with other antibacterial drugs, they are widely used in aquaculture, animal husbandry, and medicine to prevent and treat bacterial infections in animals. However, their extensive use may lead to residues in animal-derived foods such as seafood, meat, eggs, and environmental water bodies. Long-term dietary ingestion of residual fluoroquinolone antibiotics by humans may not only cause potential health risks such as gastrointestinal reactions, central nervous system symptoms, or liver damage, but more seriously, it can induce bacterial resistance, severely impacting the clinical efficacy of these drugs. To ensure food safety and public health, establishing efficient and highly sensitive detection methods to monitor trace amounts of fluoroquinolone antibiotic residues in food is crucial. However, due to the complexity of the food matrix and the extremely low level of drug residues, the efficient extraction and purification of trace fluoroquinolone antibiotics from complex matrices presents significant technical challenges.

[0003] While existing solid-phase extraction (SPE) techniques are commonly used, they suffer from drawbacks such as cumbersome adsorbent filling, low recovery efficiency, and complex operation. Therefore, developing novel enrichment and purification materials that are highly efficient, selective, possess high adsorption capacity, enable rapid separation, and are reusable is crucial for the accurate detection of trace fluoroquinolone antibiotics in complex samples. Summary of the Invention

[0004] This invention aims to at least solve one of the technical problems existing in the prior art. Therefore, one objective of this invention is to propose a nanomaterial for enriching fluoroquinolone antibiotics. This nanomaterial has abundant binding sites, large specific surface area and pore size, good stability, and high reusability, showing broad application prospects in the enrichment of trace harmful substances. It is particularly suitable for the extraction and purification of fluoroquinolone antibiotics in complex samples, significantly shortening sample pretreatment time, and exhibiting large adsorption capacity and high extraction efficiency.

[0005] Magnetic solid-phase extraction (MSPE) is a dispersion solid-phase extraction method that primarily uses magnetic or magnetically imbued materials as adsorbents for analytes. It is widely used due to its speed, simplicity, environmental friendliness, and high extraction efficiency. Compared to conventional solid-phase extraction (SPE), MSPE eliminates the process of filling SPE columns with adsorbent. Instead, magnetic nanomaterials are dispersed in the sample solution, and the material is brought into full contact with the sample through shaking or vortexing to achieve rapid enrichment of trace analytes. Covalent organic frameworks (COFs) are novel ordered crystalline porous polymers whose structures can be pre-designed by altering the composition and linkage of organic monomers. Magnetic COFs overcome the drawbacks of COFs, such as difficulty in recycling and complex operation, and show promising application prospects as adsorbents in magnetic solid-phase extraction technology.

[0006] According to one aspect of the present invention, a nanomaterial for enriching fluoroquinolone antibiotics is provided. The nanomaterial comprises: a core formed of iron(III) oxide nanoparticles; and a shell covering at least a portion of the surface of the core, the shell being composed of repeating units represented by Formula I.

[0007] The nanomaterials used for the enrichment of fluoroquinolone antibiotics use iron oxide nanoparticles as the core, exhibiting superparamagnetism and easy adsorption and separation. This solves the problems of low density, difficulty in separation, recycling, and cumbersome operation associated with non-magnetic covalent organic framework materials used to form the shell. The shell formed by the multi-ring repeating unit shown in Formula I has abundant binding sites and strong intermolecular forces. The magnetic covalent organic framework material of the shell in the embodiments of the present invention has the advantages of porous and ordered crystal structure, large specific surface area and pore size, good stability, and high reusability, and has broad application prospects in the enrichment of fluoroquinolone antibiotics.

[0008]

[0009] Formula I

[0010] In addition, the magnetic nano-enrichment material of the present invention may also have the following additional technical features:

[0011] The shell has a porous mesh structure. The greater the thickness, the more layers of repeating units in the shell material, and the greater the adsorption capacity.

[0012] The shell has a peak pore size distribution of 3-10 nm, preferably 3.8 nm; a thickness of 100-160 nm, and an average thickness of 130 nm. Therefore, it exhibits good adsorption performance for fluoroquinolone antibiotics. The 3.8 nm mesopore size, being larger than the target molecule diameter, allows for spatial intercalation with the target molecule.

[0013] The particle size of the nucleus in this invention is 150~250 nm.

[0014] The specific surface area of ​​the nanomaterials used in this invention for enriching fluoroquinolone antibiotics is 120.75 m². 2 ·g -1 Therefore, it has a large specific surface area and strong adsorption capacity.

[0015] A second aspect of the present invention is to provide a method for preparing nanomaterials enriched with fluoroquinolone antibiotics, as described in the first aspect of the present invention. The method includes:

[0016] S1, mix iron oxide nanoparticles with an amino monomer in tetrahydrofuran, sonicate, and then stir for the first time to fully dissolve and obtain a first mixture. The amino monomer is selected from any one of 2,4,6-tris(4-aminophenyl)-1,3,5-triazine and 1,3,5-tris(4-aminophenyl)benzene.

[0017] S2, the aldehyde monomer, catalyst, and the first mixture obtained in S1 are contacted and stirred a second time to obtain the fluoroquinolone antibiotic enriched nanomaterial. The catalyst is acetic acid, and the aldehyde monomer is selected from any one of 2,4,6-trihydroxybenzene-1,3,5-tricarboxaldehyde, 2,4,6-tris(4-aldehydephenyl)-1,3,5-triazine, and 3,3',5,5'-tetraaldehyde-4,4'-dihydroxybiphenyl.

[0018] Preferably, the amino monomer is 2,4,6-tris(4-aminophenyl)-1,3,5-triazine; and the aldehyde monomer is 2,4,6-trihydroxybenzene-1,3,5-tricarboxaldehyde. Using the first mixture as a bridge, and 2,4,6-tris(4-aminophenyl)-1,3,5-triazine and 2,4,6-trihydroxybenzene-1,3,5-tricarboxaldehyde as functional monomers, enriched nanomaterials with a large specific surface area and an ordered porous structure are obtained on the surface of iron oxide nanoparticles via a Schiff base reaction.

[0019] In S1 of the method for preparing fluoroquinolone antibiotic enrichment nanomaterials of the present invention, the mass ratio of iron oxide nanoparticles to amino monomers is 1 mg:(3~4) mg; in S2, the mass ratio of iron oxide nanoparticles to aldehyde monomers is 1 mg:(2~3) mg.

[0020] The stirring temperature in both S1 and S2 is 55~75 ℃, and the stirring speed is 400~800 rpm.

[0021] Preferably, the mass ratio of iron oxide nanoparticles to the amino monomer is 1:3.83, and the mass ratio of iron oxide nanoparticles to the aldehyde monomer is 1:2.3.

[0022] The preferred mass ratio of iron oxide nanoparticles to 2,4,6-tris(4-aminophenyl)-1,3,5-triazine is 1 mg:(3~4) mg, and the mass ratio of iron oxide nanoparticles to 2,4,6-trihydroxybenzene-1,3,5-tricarboxaldehyde is 1 mg:(2~3) mg.

[0023] The preferred mass ratio of iron oxide nanoparticles to 2,4,6-tris(4-aminophenyl)-1,3,5-triazine is 1:3.83, the mass ratio of iron oxide nanoparticles to 2,4,6-trihydroxybenzene-1,3,5-tricarboxaldehyde is 1 mg:(2~3) mg, and the molar ratio of 2,4,6-tris(4-aminophenyl)-1,3,5-triazine to 2,4,6-trihydroxybenzene-1,3,5-tricarboxaldehyde is 1:1.

[0024] At this ratio, the two monomers can react fully, and the resulting nanomaterials for enriching fluoroquinolone antibiotics have a better core-shell structure and a relatively high yield.

[0025] The present invention also includes the application of fluoroquinolone antibiotic enrichment nanomaterials in the adsorption and enrichment of fluoroquinolone antibiotics, wherein the fluoroquinolone antibiotic enrichment nanomaterials are the aforementioned fluoroquinolone antibiotic enrichment nanomaterials.

[0026] The method for enriching fluoroquinolone antibiotics using the above-mentioned nanomaterials is as follows:

[0027] (1) Take the fluoroquinolone antibiotic enrichment nanomaterials and place them in the sample solution. The mass ratio of the nanomaterials to the volume of the sample solution is (1~10) mg:10 mL. Vortex extract the nanomaterials, discard the supernatant, and obtain the precipitate. The pH of the sample solution is 2~10, and the vortex extraction time is 2~30 min.

[0028] (2) Add eluent with a formic acid:methanol volume ratio of 5:95~40:60 to the precipitate for elution treatment, and ultrasonic elution treatment for 1~20 min. The volume ratio of eluent to sample solution is (1~7) mL:10 mL.

[0029] In another aspect, the present invention also includes a kit comprising the above-described nanomaterials for enriching fluoroquinolone antibiotics.

[0030] A third aspect of the present invention is the application of the nanomaterial or preparation method described in the first aspect of the present invention, or the kit described above, in the adsorption of fluoroquinolone antibiotics in food, wherein the fluoroquinolone antibiotic is selected from at least one of ofloxacin, pefloxacin, norfloxacin, ciprofloxacin, enrofloxacin, and sarafloxacin.

[0031] The magnetic nano-enrichment material of the present invention has a strong and fast adsorption capacity for fluoroquinolone antibiotics and is suitable for the adsorption and extraction of fluoroquinolone antibiotics in complex samples.

[0032] The magnetic nano-enrichment material of this invention has an adsorption capacity of 163.5-256.7 mg·g. -1 Therefore, the adsorption capacity of this magnetic nanomaterial can efficiently enrich fluoroquinolone antibiotics in complex samples.

[0033] The magnetic nano-enrichment material of this invention has a specific surface area of ​​120.75 m². 2 ·g -1 Therefore, it has a large specific surface area and strong adsorption capacity.

[0034] Beneficial effects

[0035] The present invention has achieved the following beneficial effects:

[0036] (1) Highly efficient adsorption and rapid equilibrium

[0037] The fluoroquinolone antibiotic enrichment nanomaterial (M-TTA-Tp-COF) of this invention possesses superparamagnetism and a high specific surface area (120.75 m²·g). -1 It has an ordered porous structure (with a pore size distribution peak of 3.8 nm), and the adsorption time for fluoroquinolone antibiotics is 8 min, the desorption time is 3 min, and the adsorption capacity is 163.5-256.7 mg g-1, which significantly improves the extraction efficiency of trace target substances in complex samples.

[0038] (2) Magnetic separation operation is simple

[0039] The present invention provides a nanomaterial for enriching fluoroquinolone antibiotics, which uses iron oxide nanoparticles as the core and endows the material with superparamagnetism. It can be rapidly separated by an external magnetic field, avoiding the cumbersome operation of filling columns and centrifugation steps in traditional solid phase extraction, and is suitable for sample pretreatment. M-TTA-Tp-COF performs magnetic solid phase extraction on fluoroquinolone antibiotics in complex samples, with higher adsorption capacity and faster adsorption process.

[0040] (3) High stability and reusable

[0041] The shell is composed of a covalent organic framework (COF), which has high chemical stability and can be reused at least 10 times without degradation of adsorption performance, reducing the cost of use and meeting green and environmental protection requirements.

[0042] (4) Selective enrichment and wide applicability

[0043] 2,4,6-tris(4-aminophenyl)-1,3,5-triazine and 2,4,6-trihydroxybenzene-1,3,5-tricarboxaldehyde were selected as functional monomers. The π-π interactions and hydrogen bonding sites in the shell can specifically adsorb six common fluoroquinolone antibiotics, such as ofloxacin and ciprofloxacin.

[0044] (5) The preparation process is mild

[0045] The preparation method of this invention is carried out by Schiff base reaction under mild conditions (65°C, acetic acid catalysis), without the need for complex purification steps. It is a highly atom-economical reaction and suitable for large-scale production.

[0046] This invention effectively solves the problems of difficult adsorbent separation, cumbersome operation, and slow adsorption rate in the prior art, and provides an efficient and reliable enrichment and purification solution for the trace detection of fluoroquinolone antibiotics in food and environmental samples. Attached Figure Description

[0047] Figure 1 A comparison chart of tetrahydrofuran, methanol, and ethanol as organic solvents was selected for comparison.

[0048] Figure 2 The recovery rates of fluoroquinolone antibiotics for six materials;

[0049] Figure 3 Scanning electron microscope (SEM) and transmission electron microscope (TEM) images of iron oxide nanoparticles and M-TTA-Tp-COF prepared in Example 1;

[0050] in, Figure 3 a and Figure 3 c shows scanning electron microscope (SEM) and transmission electron microscope (TEM) images of iron(III) oxide nanoparticles. Figure 3 b and Figure 3 d shows the scanning electron microscope (SEM) and transmission electron microscope (TEM) images of iron oxide nanoparticles M-TTA-Tp-COF.

[0051] Figure 4 To perform physical characterization of the iron oxide nanoparticles and the M-TTA-Tp-COF prepared in Example 1;

[0052] in, Figure 4 Infrared spectroscopy characterization was performed on the iron oxide nanoparticles and the M-TTA-Tp-COF prepared in Example 1. Figure 4b is a schematic diagram showing the specific surface area of ​​iron(III) oxide nanoparticles and M-TTA-Tp-COF prepared in Example 1. Figure 4 c is a schematic diagram of the pore size distribution of M-TTA-Tp-COF;

[0053] Figure 5 This is a schematic diagram illustrating the optimized MSPE purification process conditions for preparing fluoroquinolone antibiotics as described in Example 1.

[0054] in, Figure 5 a and Figure 5 b is a schematic diagram illustrating the optimization of elution solvent types. Figure 5 c is a schematic diagram illustrating the optimization of M-TTA-Tp-COF dosage. Figure 5 Figure d shows a schematic diagram of the optimization of the pH of the adsorption solution. Figure 5 e is a schematic diagram illustrating the optimization of adsorption time during the MSPE process. Figure 5 f is a schematic diagram illustrating the optimization of the amount of elution solvent used in the MSPE process. Figure 5 g is a schematic diagram illustrating the optimization of elution time during the MSPE process;

[0055] Figure 6 Static and kinetic adsorption results of the magnetic covalent organic framework for M-TTA-Tp-COF prepared in Example 1, and a schematic diagram of the fitting.

[0056] in, Figure 6 a and 6b are schematic diagrams of static adsorption results. Figure 6 c and 6d are schematic diagrams of the kinetic adsorption results;

[0057] Figure 7 A schematic diagram illustrating the MSPE replication of M-TTA-Tp-COF prepared in Example 1 for use with fluoroquinolone antibiotics;

[0058] in, Figure 7 a is a schematic diagram illustrating the number of times M-TTA-Tp-COF can be reused. Figure 7 b is a transmission electron microscope image after M-TTA-Tp-COF has been reused 10 times. Figure 7 c is a schematic diagram of the X-ray diffraction spectrum data before and after 10 repeated uses of M-TTA-Tp-COF;

[0059] Figure 8 This is a schematic diagram showing the selectivity results of M-TTA-Tp-COF. Detailed Implementation

[0060] According to one aspect of the present invention, a nanomaterial for enriching fluoroquinolone antibiotics is provided. The nanomaterial for enriching fluoroquinolone antibiotics according to embodiments of the present invention uses iron oxide nanoparticles as the core, exhibiting superparamagnetism and easy adsorption and separation. This solves the problems of difficulty in separation, recycling, and cumbersome operation caused by the low density of non-magnetic covalent organic framework materials used to form the shell. The shell formed by the multi-ring repeating unit shown in Formula I has abundant binding sites and strong intermolecular forces. The magnetic covalent organic framework material of the shell in the embodiments of the present invention has advantages such as a porous and ordered crystal structure, large specific surface area and pore size, good stability, and high reusability. It has broad application prospects in the enrichment of fluoroquinolone antibiotics, especially suitable for the extraction of fluoroquinolone antibiotics from complex samples. It significantly shortens the sample pretreatment time, has a large adsorption capacity, and high extraction efficiency. In some embodiments, the adsorption and desorption of fluoroquinolone antibiotics can be completed in just a few minutes, with advantages such as simple operation, environmental friendliness, and high extraction efficiency.

[0061] To facilitate understanding of the fluoroquinolone antibiotic enrichment nanomaterials of the embodiments of the present invention, the fluoroquinolone antibiotic enrichment nanomaterials are explained herein. According to the embodiments of the present invention, the nanomaterials include:

[0062] nucleus

[0063] According to an embodiment of the present invention, the core is formed from iron oxide nanoparticles. Therefore, using iron oxide nanoparticles as the core results in superparamagnetism, facilitating adsorption and separation, thus solving the problems of difficulty in separation, recycling, and cumbersome operation associated with non-magnetic covalent organic framework materials due to their low density.

[0064] The particle size of the core in this invention is 150~250 nm. Therefore, the nanomaterial has a suitable particle size and a large specific surface area.

[0065] case

[0066] The shell of this invention covers at least a portion of the surface of the core, and the shell is composed of repeating units as shown in Formula I. Thus, the covalent organic framework material formed by the multi-ring repeating units of Formula I has abundant binding sites, large specific surface area and pore size, high stability, and high reusability, and has broad application prospects in the enrichment of trace hazardous substances.

[0067] The shell of this invention has a porous mesh structure. As a result, it has a large specific surface area and a large adsorption capacity.

[0068] The shell has a pore size distribution of 3–10 nm and a thickness of 100–160 nm. Therefore, the shell has a mesoporous structure, which allows for spatial intercalation with the target analyte, facilitating the adsorption of fluoroquinolone compounds. Furthermore, the large shell thickness results in a high adsorption capacity.

[0069] The specific surface area of ​​the shell is 100~140 m². 2 ·g -1 Therefore, it has a large specific surface area, high adsorption efficiency, and large adsorption capacity.

[0070] Magnetic covalent organic framework materials can be reused at least 10 times. Therefore, magnetic covalent organic framework materials can be reused many times and have low usage costs.

[0071] Another objective of this invention is to provide a method for preparing the aforementioned nanomaterials for the enrichment of fluoroquinolone antibiotics. This method uses iron oxide nanoparticles as the core, first coating the surface with an amino monomer, then adding an aldehyde monomer; the amino monomer and the aldehyde monomer undergo a Schiff base reaction to form a magnetic covalent organic framework shell in situ on the core surface, thereby obtaining the nanomaterials. The nanomaterials prepared by this invention combine the core advantages of iron oxide with the structural characteristics of a covalent organic framework: on the one hand, they exhibit superparamagnetism, enabling rapid magnetic separation and simplifying the adsorption and elution processes; on the other hand, they possess abundant binding sites, strong intermolecular forces, a porous and ordered crystal structure, and a large specific surface area and pore size. Furthermore, the material also possesses excellent chemical stability and good reusability. Therefore, this material is particularly suitable for the efficient enrichment of trace fluoroquinolone antibiotics in complex samples, with broad application prospects. Simultaneously, the preparation method provided by this invention has low equipment requirements, mild reaction conditions, simple operation, and is environmentally friendly, making it highly valuable for widespread application.

[0072] To facilitate understanding of the method for preparing nanomaterials for enriching fluoroquinolone antibiotics according to embodiments of the present invention, the method is explained herein. According to embodiments of the present invention, the method includes:

[0073] S1 iron oxide nanoparticles and amino monomer prepolymer

[0074] The iron oxide nanoparticles and amino monomers were ultrasonically stirred to obtain a first mixture. This allowed the amino monomers and iron oxide nanoparticles to fully dissolve and come into contact in the organic solvent.

[0075] The mass ratio of iron oxide nanoparticles to the amino monomer is 1 mg:(3~4) mg, preferably 1:3.83. This facilitates the full binding of the amino monomer to the iron oxide nanoparticles.

[0076] The sonication time is 20 min. This facilitates thorough mixing of the amino monomer and the iron oxide nanoparticles. Stirring is performed at 55-75°C and 400-800 rpm for 20-60 min, preferably at 65°C and 500 rpm for 40 min. This facilitates the full adhesion of the amino monomer to the surface of the iron oxide nanoparticles, allowing the amino monomer to bind to the core.

[0077] S2 Schiff base reaction

[0078] The aldehyde monomer is mixed with tetrahydrofuran and ultrasonically treated to fully dissolve it, forming a second mixture. The second mixture, the catalyst, and the first mixture obtained in step S1 are then mixed and stirred. The amino monomer in the first mixture reacts with the aldehyde monomer in the second mixture via a Schiff base reaction to obtain the nanomaterial. Thus, the amino monomer and the aldehyde monomer form a shell with repeating units of formula I on the surface of the iron(III) oxide nanoparticles through a Schiff base reaction.

[0079] The amino monomer is 2,4,6-tris(4-aminophenyl)-1,3,5-triazine, and the aldehyde monomer is 2,4,6-trihydroxybenzene-1,3,5-tricarboxaldehyde. By analyzing the characteristics of fluoroquinolone antibiotics, the inventors rationally designed and selected the monomers used. They chose 2,4,6-tris(4-aminophenyl)-1,3,5-triazine as the amino monomer and 2,4,6-trihydroxybenzene-1,3,5-tricarboxaldehyde as the aldehyde monomer, whose benzene ring structure enables π-π interactions and hydrogen bonding with the target analyte. Through structural analysis of the target analyte, a polymer with a specific structure was synthesized using the above-mentioned amino and aldehyde monomers and coated onto the surface of iron oxide nanoparticles to form a shell material. The resulting magnetic covalent organic framework material exhibits strong adsorption specificity and high adsorption capacity for fluoroquinolone antibiotics, making it suitable for the enrichment of fluoroquinolone antibiotics in complex samples.

[0080] The molar ratio of the aldehyde monomer to the amino monomer is 1 mmol:(0.8~1.2) mmol, preferably 1:1. This mass ratio is beneficial for promoting the smooth progress of the Schiff base reaction.

[0081] The Schiff base reaction is carried out at a temperature of 55–75 °C for 60–140 min, preferably at 65 °C for 120 min. This facilitates a thorough and efficient Schiff base reaction, resulting in a high yield of the organic framework polymer.

[0082] According to an embodiment of the present invention, the Schiff base reaction uses acetic acid as a catalyst. This results in high catalytic efficiency, which is beneficial for the efficient conduct of the Schiff base reaction.

[0083] According to another aspect of the present invention, a method for enriching fluoroquinolone antibiotics is provided, which utilizes the aforementioned nanomaterials for the enrichment of fluoroquinolone antibiotics. Thus, the enrichment and purification treatment using the aforementioned magnetic covalent organic framework material exhibits strong adsorption specificity, high extraction efficiency, large adsorption capacity, and good adsorption effect for fluoroquinolone antibiotics. Furthermore, the operation is simple and rapid, making it particularly suitable for the extraction of fluoroquinolone antibiotics from complex samples. Moreover, this method has a short adsorption time and requires a small amount of nanomaterial; adsorption and desorption of fluoroquinolone antibiotics can be completed within minutes using only a very small amount. It has advantages such as simple operation, environmental friendliness, and high extraction efficiency. It should be noted that the nanomaterial possesses all the technical characteristics and effects of the aforementioned nanomaterials, which will not be elaborated further here.

[0084] Fluoroquinolone antibiotics are selected from at least one of ofloxacin, pefloxacin, norfloxacin, ciprofloxacin, enrofloxacin, and sarafloxacin.

[0085] The adsorption capacity of nanomaterials enriched with fluoroquinolone antibiotics ranges from 163.5 to 256.7 mg·g. -1 Therefore, this nanomaterial has strong adsorption capacity and large adsorption amount, enabling it to efficiently extract fluoroquinolone antibiotics from complex samples.

[0086] The adsorption time for enriching nano-fluoroquinolone antibiotics is 8 min, indicating that the nanomaterial has a high adsorption rate and can rapidly extract fluoroquinolone antibiotics from complex samples.

[0087] According to an embodiment of the present invention, the amount of nanomaterial used is 1-10 mg based on a 10 mL liquid sample. Therefore, the amount of nanomaterial used is reasonable, which is beneficial for the full extraction of fluoroquinolone antibiotics from the liquid sample while avoiding excessive use of nanomaterial.

[0088] According to an embodiment of the present invention, the extraction time is 2-30 min. As a result, the extraction recovery rate of fluoroquinolone antibiotics tends to stabilize.

[0089] According to embodiments of the present invention, the method is carried out under conditions of pH 2 to 10. This results in a high extraction recovery rate for fluoroquinolone antibiotics.

[0090] According to embodiments of the present invention, elution is performed using a formic acid:methanol volume ratio of 5:95 to 40:60. This results in high elution efficiency and high recovery rates of fluoroquinolone antibiotics.

[0091] According to embodiments of the present invention, the elution time is 1-20 min, and the eluent volume is 1-7 mL. Another objective of the present invention is to provide a novel nanomaterial for the enrichment of fluoroquinolone antibiotics. The preparation process of this material has low equipment dependence, mild and controllable reaction conditions, and does not require harsh extreme environments. Furthermore, the preparation method is simple, low-cost, and environmentally friendly, solving the problems of complex synthesis steps and high energy consumption in existing technologies, and possesses good potential for industrial application.

[0092] This invention also proposes the application of the aforementioned nanomaterial in the pretreatment of complex samples. Due to its porous and ordered structure and specific functional group arrangement, this material exhibits extremely high specificity for fluoroquinolone antibiotics. In application, the material demonstrates rapid adsorption kinetics, enabling efficient capture and release of the target analyte within minutes. This significantly improves recovery rate and sensitivity, and effectively resists interference from complex matrices, achieving efficient and rapid sample enrichment.

[0093] The fluoroquinolone antibiotics of the present invention are selected from at least one of ofloxacin, pefloxacin, norfloxacin, ciprofloxacin, enrofloxacin, and sarafloxacin.

[0094] Example 1

[0095] Choice of reaction solvent

[0096] The organic solvent is selected from at least one of methanol, ethanol, and tetrahydrofuran. This application systematically investigated the dispersion of iron oxide nanoparticles and 2,4,6-tris(4-aminophenyl)-1,3,5-triazine in different reaction solvents (tetrahydrofuran, methanol, and ethanol). Figure 1 As shown, iron oxide nanoparticles and 2,4,6-tris(4-aminophenyl)-1,3,5-triazine are uniformly dispersed in tetrahydrofuran, and precipitates are formed in methanol and ethanol. Good dispersibility ensures sufficient contact in the reaction system, thus leading to better reaction results. Therefore, tetrahydrofuran was chosen as the reaction solvent for the experiments in this application.

[0097] Example 2

[0098] Monomer selection

[0099] Six different materials were synthesized by combining ammonia monomers (2,4,6-tris(4-aminophenyl)-1,3,5-triazine (TTA), 1,3,5-tris(4-aminophenyl)benzene (TAPB)) and aldehyde monomers (2,4,6-trihydroxyphenyl-1,3,5-tricarboxaldehyde (Tp), 2,4,6-tris(4-aldehydephenyl)-1,3,5-triazine (TAAT), 3,3',5,5'-tetraaldehyde-4,4'-dihydroxybiphenyl (TFPB)) in pairs according to a 1:1 aldehyde-to-amino ratio. These materials were named (M-TTA-Tp-COF, M-TTA-TAAT-COF, M-TTA-TFPB-COF, M-TAPB-Tp-COF, M-TAPB-TAAT-COF, M-TAPB-TFPB-COF). The recoveries of fluoroquinolone antibiotics by these six materials were compared. Figure 2 The experimental results showed that M-TTA-Tp-COF, synthesized from 2,4,6-tris(4-aminophenyl)-1,3,5-triazine and 2,4,6-trihydroxybenzene-1,3,5-tricarboxaldehyde, had the highest recovery rate for fluoroquinolone antibiotics.

[0100] Example 3

[0101] Confirmation of reaction time

[0102] In the method for optimizing the reaction time, the reaction system was carried out under a constant temperature of 65 °C. Systematic observation revealed a regular color change in the reaction solution over time: initially, it was the inherent black color of the iron(III) oxide nanoparticles (Fe3O4) in the initial stage of the reaction (approximately 10 min); after 30 min, it gradually turned brown; continuing the reaction to 60 min, it further turned pale yellow; finally, it stabilized as a deep yellow at 120 min. Further extending the reaction time thereafter did not result in a significant color change, therefore 120 min was determined as the reaction endpoint. Based on these observations, to balance reaction efficiency and yield, the optimal reaction time was determined to be 120 min.

[0103] Example 4

[0104] Selection of reaction temperature

[0105] The experimental system of this application investigated the effect of different reaction temperatures (55 ℃, 65 ℃, and 75 ℃) on the synthesis process. Under the condition of a fixed reaction time of 120 min, the change in color of the reaction system was used as the basis for judging whether the reaction was in progress.

[0106] Specifically, when the temperature was controlled at 55 °C, the reaction system remained black throughout the process, indicating that the iron oxide nanoparticles failed to react effectively with the aldehyde and amine monomers, and the system retained the color of the iron oxide nanoparticles themselves. When the temperature was raised to 70 °C, since this temperature exceeded the boiling point of the solvent tetrahydrofuran (66 °C), the solvent evaporated completely after only 10 minutes, causing the reaction to stop. However, under the reaction conditions of 60 °C, the system color successfully changed from the initial black to a deep yellow, indicating that the reaction could proceed normally and completely at this temperature.

[0107] Example 5

[0108] Preparation of M-TTA-Tp-COF

[0109] M-TTA-Tp-COF was synthesized using iron oxide nanoparticles as the magnetic core and 2,4,6-tris(4-aminophenyl)-1,3,5-triazine and 2,4,6-trihydroxybenzene-1,3,5-tricarboxaldehyde as functional monomers. The preparation process is as follows:

[0110] (a) In a 100 mL two-necked round-bottom flask, 100 mg of iron oxide nanoparticles and 0.36 mmol of 2,4,6-tris(4-aminophenyl)-1,3,5-triazine were added to 22 mL of tetrahydrofuran and sonicated for 20 min.

[0111] (b) The product from step (a) was mechanically stirred at 65 °C for 40 min to allow some of the 2,4,6-tris(4-aminophenyl)-1,3,5-triazine to be first anchored to the surface of the iron oxide nanoparticles via hydrogen bonds, thus performing prepolymerization.

[0112] (c) 0.36 mmol of 2,4,6-trihydroxybenzene-1,3,5-tricarboxaldehyde was uniformly dispersed in 8 mL of tetrahydrofuran, and added dropwise along with 500 µL of acetic acid to the reaction system of step (b) with stirring. After the addition was complete, the mixture was mechanically stirred at 65 °C for 120 min.

[0113] (d) The product was washed with methanol and acetonitrile alternately until the supernatant was clear, and then dried in an oven at 65 °C for 12 h to obtain M-TTA-Tp-COF.

[0114] Example 6

[0115] Characterization of M-TTA-Tp-COF

[0116] This experimental example demonstrates a detailed characterization of the M-TTA-Tp-COF obtained in Example 1 to prove its successful preparation and excellent physicochemical properties. Details are as follows:

[0117] 1. The Fe3O4 nanoparticles and M-TTA-Tp-COF were characterized by scanning electron microscopy and transmission electron microscopy. The results are as follows: Figure 3 a and Figure 3 As shown in c, the spherical iron oxide nanoparticles have a size of approximately 200 nm. Furthermore, compared to the iron oxide nanoparticles, a distinct shell of approximately 130 nm iron oxide nanoparticles and the TTA-Tp-COF combination is clearly observed on the surface of the iron oxide nanoparticles on M-TTA-Tp-COF. Figure 3 b and Figure 3 d) This confirms the successful synthesis of TTA-Tp-COF based on the magnetism of iron oxide nanoparticles. This avoids the self-aggregation of iron oxide nanoparticles.

[0118] 2. We employed Fourier transform infrared (FTIR) spectroscopy to characterize the iron(III) oxide nanoparticles and M-TTA-Tp-COF, using characteristic peaks to determine the successful synthesis of M-TTA-Tp-COF. This confirmed the successful synthesis of M-TTA-Tp-COF. Figure 4 As shown in figure a, the FTIR spectra of iron oxide nanoparticles and M-TTA-Tp-COF are at approximately 614.21 cm⁻¹. -1 and 611.92 cm -1 Characteristic peaks are observed at the [location]. These peaks are mainly attributed to the Fe-O-Fe stretching vibration, indicating the presence of iron tetroxide nanoparticles in the M-TTA-Tp-COF composite material.

[0119] Unlike iron oxide nanoparticles, M-TTA-Tp-COF has a spectrum at 3435.50 cm⁻¹. -1 1618.58 cm -1 1592.53 cm -1 1573.25 cm -1 1515.54 cm -1 1461.00 cm -1 and 1292.69 cm -1 A distinct absorption band is observed at approximately 3435.50 cm⁻¹. Analysis of these peaks suggests the following attribution: -1 The broadband width is likely due to the OH stretching vibration, possibly originating from the hydroxyl group (-OH) in the side chain of the aldehyde monomer. 1618.58 cm -1The peak corresponds to the C=N stretching vibration, a key characteristic vibration of the imine bond, providing strong evidence for the successful formation of M-TTA-Tp-COF. At 1592.53 cm⁻¹ -1 and 1461.00 cm -1 The absorption peak at 1573.25 cm⁻¹ is related to the stretching vibrations of the aromatic C=C structure, which likely originate from the benzene ring in the aldehyde monomer and the triazine ring in the amino monomer. -1 The peak at 1515.54 cm⁻¹ may be attributed to the conjugate C=N stretching vibration, possibly due to a splitting displacement resulting from the interaction with the aromatic system. -1 The absorption peak at 1292.69 cm⁻¹ is characteristic of the C=N stretching vibration within the triazine ring. -1 The band at this location represents the CN stretching vibration, which further confirms the presence of imine bonds and provides additional confirmation for the formation of covalent organic frameworks. Most importantly, at approximately 3300 cm⁻¹… -1 There are no very strong and broad NH stretching vibration peaks nearby, which are characteristic of primary amines (-NH2), nor are there any at approximately 1700 cm⁻¹. -1 The presence of a C=O stretching vibration peak nearby indicates the absence of an aldehyde group (-CHO). These findings suggest that the amino and aldehyde groups in the starting material were largely consumed during the reaction. This further confirms the successful synthesis of the imine bond (-C=N-) in the final product. Fourier transform infrared spectroscopy (FTIR) results jointly confirm the successful synthesis of the M-TTA-Tp-COF material.

[0120] 3. For example Figure 4 As indicated by b, characterization revealed that the specific surface area of ​​M-TTA-Tp-COF is 120.75 m². 2 ·g -1 The surface area of ​​the iron oxide nanoparticles is 15.6 m². 2 ·g -1 This demonstrates that the specific surface area of ​​M-TTA-Tp-COF is much higher than that of iron oxide nanoparticles. For example... Figure 4 As shown in Figure c, the pore size distribution indicates that the peak pore size of M-TTA-Tp-COF is 3.8 nm. This indicates that it has mesoporous characteristics and a large specific surface area, providing a suitable environment for the adsorption of fluoroquinolone antibiotics. Therefore, M-TTA-Tp-COF is suitable for the enrichment and detection of fluoroquinolone antibiotics.

[0121] Example 7

[0122] Optimization of MSPE adsorption-desorption conditions

[0123] In this embodiment, the nanomaterials prepared in Example 1 were used for magnetic solid-phase extraction of six fluoroquinolone antibiotics. The difference lies in the optimization of several parameters, including the type of elution solvent, the amount of M-TTA-Tp-COF, the pH of the extraction solution, the extraction time, the elution volume, and the elution time. The effects of different magnetic solid-phase extraction conditions on the extraction recovery rate were investigated. Specifically, the effects of the type of elution solvent, the amount of M-TTA-Tp-COF nanomaterial (1~10 mg), the pH of the extraction solution (1~10), the extraction time (2~30 min), the amount of elution solvent (1~7 mL), and the elution time (1~20 min) on the extraction recovery rate of the six fluoroquinolone antibiotics were investigated. The specific operation is as follows:

[0124] (1) Accurately weigh 5.0 mg M-TTA-Tp-COF and place it in 10 mL of sample solution. Vortex it rapidly for 8 min on a multi-tube vortex apparatus (1800 rpm). Discard the supernatant with the help of an external magnet.

[0125] (2) Add 2 mL of eluent with a volume ratio of formic acid to methanol of 3:7 to the precipitate and sonicate for 3 min to elute the fluoroquinolone antibiotics.

[0126] (3) Separate M-TTA-Tp-COF from the eluent using an external magnet, transfer the eluent to a nitrogen blow-off tube, and blow it with nitrogen at 35°C until it is nearly dry;

[0127] (4) Add 1 mL of initial mobile phase (methanol to 0.1% formic acid water in a volume ratio of 5:95) for redissolution, filter through a 0.22 μm filter membrane, and detect by HPLC-MS / MS.

[0128] All experiments were set up in triplicate, and the results were averaged. The error bars in the graph represent the standard deviation between the parallel data.

[0129] Experimental results are as follows Figure 5 As shown in a-5g, specifically, as Figure 5 As shown in Figure a, the elution effect of the target analyte was not ideal when using methanol, acetonitrile, acetone, and their ammonia solutions alone. However, the introduction of formic acid into the solvent system significantly improved the recovery rate, with the 5% formic acid-methanol solution showing the best performance. Further investigation was conducted on the effect of the formic acid-methanol volume ratio on the recovery rate. Figure 5 (b) It was found that the recovery rate reached its peak when the volume ratio of the two components was 3:7; therefore, this ratio was selected as the optimal elution condition. Figure 5 As shown in c, the extraction efficiency of the six fluoroquinolone antibiotics increased with increasing adsorption dose, reaching a peak at 5.0 mg and then stabilizing at 80-110%, indicating that only a small amount of adsorbent is needed to achieve efficient enrichment; Figure 5As shown in d, the extraction recoveries of the six fluoroquinolone antibiotics reached their peak at pH 6; Figure 5 As shown in Figure e, the extraction efficiency increases with time; the adsorption process of the six fluoroquinolone antibiotics reaches equilibrium at 8 min and remains relatively stable between 8 and 20 min. Therefore, the optimal adsorption time for subsequent studies was determined to be 8 min; Figure 5 As shown in f, the recovery rate increases with the eluent volume from 0.5 mL to 2 mL, and stabilizes at a relatively high level when the volume exceeds 2 mL; Figure 5 As shown in g, the recoveries of the six fluoroquinolone antibiotics peaked at 3 min and remained relatively stable over the period of 3–20 min.

[0130] In summary, the nanomaterials used as magnetic solid-phase extraction adsorbents in the embodiments of the present invention have advantages such as low material consumption, short extraction time, low organic reagent consumption, and simple operation, and have a very broad application prospect.

[0131] Experimental Example 8

[0132] M-TTA-Tp-COF adsorption capacity for fluoroquinolone antibiotics

[0133] In this experimental example, the adsorption capacity of M-TTA-Tp-COF prepared in Example 1 for six fluoroquinolone antibiotics in complex samples was studied, as follows:

[0134] This study used a single standard solution of a fluoroquinolone antibiotic, with 2 mg of the material used as an adsorbent in the range of 1–400 mg·L⁻¹. -1 The adsorption capacity was measured within a certain concentration range. The adsorption capacity of the M-TTA-Tp-COF adsorbent gradually increased with increasing target analyte concentration, and then tended to reach equilibrium after reaching saturation adsorption capacity. Figure 6 As shown in a. Enrofloxacin at 250 mg / L -1 It reaches adsorption equilibrium at 300 mg / L, while other fluoroquinolone antibiotics reach adsorption equilibrium at 300 mg / L. -1 Equilibrium was reached at this time. The equilibrium adsorption capacities of ofloxacin, pefloxacin, norfloxacin, ciprofloxacin, enrofloxacin, and sarafloxacin were 210.9, 253.9, 239.4, 235.2, 163.5, and 256.7 mg·g, respectively. -1 Compared to other fluoroquinolone antibiotics, enrofloxacin reaches adsorption equilibrium at lower concentrations, likely due to its lower steric hindrance, facilitating easier access to the M-TTA-Tp-COF adsorbent. The adsorbent's excellent adsorption performance and high capacity are primarily attributed to the high specific surface area provided by its porous distribution and the synergistic effect of its bifunctional binding sites.

[0135]

[0136] Where Q is the equilibrium adsorption capacity (mg·g) -1 C0 is the initial concentration of the adsorption solution (μg·mL). -1 ), C e To achieve adsorption equilibrium, the concentration of the target analyte (μg·mL) -1 ), where m is the mass (mg) of M-TTA-Tp-COF and V is the volume (mL) of the adsorption solution.

[0137] Experimental Example 9

[0138] Adsorption isotherm of M-TTA-Tp-COF for fluoroquinolone antibiotics

[0139] In this experiment, the Langmuir and Freundlich isotherm models were used to fit the adsorption behavior of M-TTA-Tp-COF. The Langmuir isotherm model posits that on the solid surface, atoms or molecules exhibit outward residual valence forces that trap gas molecules. Since the range of these residual valence forces is proportional to the molecular diameter, the monolayer can only adsorb onto the adsorbent surface; that is, each site can only adsorb one type of fluoroquinolone antibiotic molecule.

[0140] The Freundlich isotherm model can be applied to both monolayer adsorption and adsorption on inhomogeneous surfaces. As an empirical adsorption isotherm equation for inhomogeneous surfaces, the Freundlich adsorption equation not only describes the adsorption mechanism well but is also more suitable for low-concentration adsorption, and it can explain experimental results well over a wider concentration range.

[0141] The Langmuir isotherm model is expressed as follows:

[0142]

[0143] The Freundlich isotherm model is expressed as follows:

[0144]

[0145] In the formula C e (μg·mL -1 Q represents the equilibrium concentration of the target analyte. e (mg·g -1 To balance the adsorption capacity, Q s (mg·g -1 K represents the theoretical maximum adsorption capacity. L (mL·g -1 K is the Langmuir adsorption equilibrium constant. Fis the Freundlich constant related to adsorption capacity, and n is the Freundlich constant related to adsorption strength.

[0146] The adsorption data were fitted and analyzed using the Langmuir and Freundlich models. The results are shown in Table 1. The adsorption of fluoroquinolone antibiotics by M-TTA-Tp-COF is more consistent with the Langmuir isotherm model (R0). 2 =0.9644~0.9782). Meanwhile, the separation factor (R²) calculated based on the Langmuir model... L The values ​​(0.5780~0.7013) are all within the range of 0~1, indicating that the adsorption process is favorable. Based on the assumptions of the Langmuir model—that the adsorbent surface sites are uniform and form a monolayer—it can be determined that the enrichment mechanism of M-TTA-Tp-COF for fluoroquinolone antibiotics mainly relies on π-π stacking and hydrogen bonding, belonging to a monolayer adsorption process dominated by chemisorption.

[0147] Table 1. Adsorption isotherm parameters of fluoroquinolone antibiotics at M-TTA-Tp-COF

[0148] Experimental Example 10

[0149] Adsorption kinetics of M-TTA-Tp-COF for fluoroquinolone antibiotics

[0150] This study investigated the mechanism of interaction between M-TTA-Tp-COF and fluoroquinolone antibiotics by controlling the adsorption time of fluoroquinolone antibiotics in a single standard solution to 5–90 min, determining when the adsorption reached equilibrium.

[0151] The data was fitted using a first-order dynamic model and a second-order dynamic model.

[0152] The expression for the first-order dynamic model is as follows:

[0153]

[0154] The expression for the second-order dynamic model is as follows:

[0155]

[0156] Q m (mg·g -1 ) and Q t (mg·g -1 ) represent the adsorption amounts at equilibrium and time t, respectively, and k1 and k2 are the rate constants of the pseudo-first-order and pseudo-second-order models, respectively.

[0157] The dynamic fitting results (Table 2) show that, compared to the pseudo-first-order model (R0), 2 The coefficient of determination for the pseudo-second-order model is > 0.94, indicating a higher R-value. 2 (>0.97), therefore, chemisorption is the main rate-determining step in the interaction between M-TTA-Tp-COF and fluoroquinolone antibiotics, which should be attributed to electrostatic and coordination interactions. This rapid adsorption kinetics is likely due to the structural advantage of the bifunctional sites, with synergistic effects leading to faster binding to the target. Furthermore, the high specific surface area may facilitate the exposure of more binding sites and improve site accessibility.

[0158] Table 2. Adsorption kinetics model of fluoroquinolone antibiotics in M-TTA-Tp-COF

[0159] Example 11

[0160] M-TTA-Tp-COF reusability study

[0161] Evaluating the reusability of nanomaterials is crucial for assessing the superior performance of adsorbents and enhancing the application potential of M-TTA-Tp-COF. In this embodiment, the used adsorbent is recycled using methanol and acetonitrile as cleaning solvents, and ultrasonically cleaned several times to ensure no target analyte residue remains on the adsorbent. Figure 7 As shown in Figure a, the adsorption capacity of M-TTA-Tp-COF remained stable over 10 consecutive cycles. Furthermore, TEM images of the material after cycling are also provided. Figure 7 b) Confirmed the integrity of its core-shell spherical structure: the iron oxide core was completely enclosed by a covalent organic framework shell with a thickness of approximately 100-160 nm, consistent with the characteristics of freshly synthesized materials. Figure 3 d). No visible cracks, peeling, or aggregation were observed in the shell, indicating that the ultrasonic dissolution step did not cause mechanical degradation or peeling of the covalent organic framework coating.

[0162] The crystallinity of covalent organic framework shells is crucial for maintaining their ordered pore structure and adsorption selectivity. For example... Figure 7 As shown in Figure c, the XRD patterns of M-TTA-Tp-COF before and after 10 cycles show that the characteristic diffraction peaks of the TTA-Tp-COF framework are almost identical, with no significant changes in peak position, intensity, or full width at half maximum (FWHM). This result confirms the maintenance of long-range crystalline order within the imine-linked network, indicating that ultrasonic treatment did not induce amorphization or significant structural distortion.

[0163] Example 12

[0164] Selective adsorption experiment of M-TTA-Tp-COF for fluoroquinolone antibiotics

[0165] In this experimental example, competitive adsorption experiments were conducted on six target antibiotics and three interfering antibiotics using M-TTA-Tp-COF prepared in Example 1, as detailed below:

[0166] This experiment used 20 μg·L -1 A mixed standard solution containing six target fluoroquinolone antibiotics and three representative interfering antibiotics: sulfadiazine (Smt), oxytetracycline (Otc), and chloramphenicol (Cap). Figure 8 As shown, the extraction recoveries of the six fluoroquinolone antibiotics ranged from 85.6% to 100.5%, while the recoveries of Smt, Otc, and Cap were lower, at 10.1%, 7.6%, and 11.6%, respectively. These results clearly confirm the adsorption specificity of M-TTA-Tp-COF for fluoroquinolone antibiotics compared to other classes of antibiotics, thus validating the selectivity of this enrichment process. These results are consistent with the proposed adsorption mechanism: the hydroxyl, imine, and triazine functional groups of this material create a suitable binding environment for the carboxyl and piperazine groups contained in fluoroquinolone antibiotics.

Claims

1. Fluoroquinolone antibiotic enrichment nanomaterials, characterized in that, include: Core: Iron oxide nanoparticles; Shell: Composed of repeating units as shown in Formula I, the shell covering at least a portion of the surface of the core body; Formula I.

2. The fluoroquinolone antibiotic enrichment nanomaterial according to claim 1, characterized in that, The core has a particle size of 150–250 nm; the shell is a porous mesh structure with a pore size distribution of 3–10 nm, a thickness of 100–160 nm, and a specific surface area of ​​100–140 m². 2 ·g -1 .

3. The method for preparing fluoroquinolone antibiotic enrichment nanomaterials according to any one of claims 1 to 2, characterized in that, Includes the following steps: S1 mixes the core-bound iron oxide nanoparticles with an amino monomer in tetrahydrofuran, sonicates them, and then stirs them to fully dissolve them to obtain a first mixture; the amino monomer is selected from any one of 2,4,6-tris(4-aminophenyl)-1,3,5-triazine and 1,3,5-tris(4-aminophenyl)benzene. In step S2, an aldehyde monomer is mixed with tetrahydrofuran and ultrasonically treated to fully dissolve it, forming a second mixture. The second mixture, the catalyst, and the first mixture obtained in step S1 are then mixed and stirred. The amino monomer in the first mixture reacts with the aldehyde monomer in the second mixture to form a shell, which covers at least a portion of the surface of the core iron oxide nanoparticles, forming a fluoroquinolone antibiotic enriched nanomaterial. The catalyst is acetic acid, and the aldehyde monomer is selected from any one of 2,4,6-trihydroxybenzene-1,3,5-tricarboxaldehyde, 2,4,6-tris(4-aldehydephenyl)-1,3,5-triazine, and 3,3',5,5'-tetraaldehyde-4,4'-dihydroxybiphenyl.

4. The method for preparing fluoroquinolone antibiotic enrichment nanomaterials according to claim 3, characterized in that, In S1, the mass ratio of iron oxide nanoparticles to amino monomers was 1 mg:(3~4) mg; the mass-volume ratio of iron oxide nanoparticles to tetrahydrofuran was 1 mg:(0.1~1) mL; the ultrasonic conditions were: frequency 40 kHz, power 500 W, temperature 25±2℃, and ultrasonic time 20 min. In S2, the mass ratio of iron oxide nanoparticles to aldehyde monomers is 1 mg:(2~3) mg; the mass-volume ratio of iron oxide nanoparticles in S1 to tetrahydrofuran in S2 is 1 mg:(0.01~0.1) mL; and the mass-volume ratio of iron oxide nanoparticles to catalyst is 1 mg:(0.005~0.05) mL.

5. The method for preparing fluoroquinolone antibiotic enrichment nanomaterials according to claim 3, characterized in that, The stirring conditions in S1 and S2 are: temperature of 55~75 ℃ and speed of 400~800 rpm; stirring time of 20~60 min in S1 and stirring time of 60~140 min in S2.

6. The method for preparing fluoroquinolone antibiotic enrichment nanomaterials according to claim 3, characterized in that, In S1, the amino monomer is 2,4,6-tris(4-aminophenyl)-1,3,5-triazine, the mass ratio of the iron oxide nanoparticles to the amino monomer is 1:3.83, the mass-volume ratio of the iron oxide nanoparticles to the tetrahydrofuran is 1 mg:0.22 mL, and the stirring time is 40 min. In S2, the aldehyde monomer is 2,4,6-trihydroxybenzene-1,3,5-tricarboxaldehyde, the mass ratio of the iron oxide nanoparticles to the aldehyde monomer is 1:2.3, the mass-volume ratio of the iron oxide nanoparticles to the tetrahydrofuran is 1 mg:0.08 mL, and the stirring time is 120 min. The stirring temperature was 65 ℃ and the stirring speed was 500 rpm for both stirring operations.

7. The use of the fluoroquinolone antibiotic enrichment nanomaterial as described in any one of claims 1 or 2 in the adsorption and enrichment of fluoroquinolone antibiotics.

8. The application as described in claim 7, characterized in that, The fluoroquinolone antibiotics are selected from at least one of ofloxacin, pefloxacin, norfloxacin, ciprofloxacin, enrofloxacin, and sarafloxacin.

9. A method for enriching fluoroquinolone antibiotics using the nanomaterials described in any one of claims 1 to 2, characterized in that, The steps are as follows: (1) Take the fluoroquinolone antibiotic enrichment nanomaterial and place it in the sample solution. The mass-volume ratio of the nanomaterial to the sample solution is (1~10) mg:10 mL. Vortex extract the nanomaterial and discard the supernatant to obtain the precipitate. The pH of the sample solution is 2~10 and the vortex extraction time is 2~30 min. The sample solution consisted of: weighing 2 g of screening sample and adding 20 mL of each solution with a concentration of 0.05 mmol·L⁻¹. -1 The solutions of disodium hydrogen phosphate and potassium dihydrogen phosphate were mixed with homogenates, vortexed for 5 min, and centrifuged at 10,000 rpm for 5 min. 10 mL of the supernatant was taken, and 10 mL of n-hexane was added. The mixture was then vortexed for 5 min and centrifuged at 10,000 rpm for 5 min to obtain the lower supernatant. (2) Add eluent to the precipitate and ultrasonically elute for 1~20 min. The eluent is composed of formic acid and methanol, and the volume ratio of formic acid to methanol is 5:95~40:

60.

10. A reagent kit, characterized in that, Nanomaterials containing fluoroquinolone antibiotics as described in any one of claims 1 to 2.

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