A raspberry-shaped iron-cobalt nano-oxide material and its preparation method and application

Abstract

The present invention provides a raspberry-shaped iron-cobalt nanooxide material, its preparation method, and application, belonging to the technical field of nanomaterial preparation. The present invention uses iron salt, cobalt salt, urea, and sodium lauryl sulfate as raw materials, and uses a hydrothermal method to prepare a cobalt-iron nanooxide precursor. The precursor is then calcined at high temperature in a tubular furnace to obtain the raspberry-shaped iron-cobalt nanooxide material. The present invention has the advantages of a simple synthesis method and low production cost. The resulting raspberry-shaped iron-cobalt nanooxide material is applied to an enzyme-free antibiotic fluorescence sensor, which has the advantages of high sensitivity, rapid detection, certain selectivity, and good stability, and is suitable for detecting ciprofloxacin and ofloxacin.

Description

Technical Field

[0001] The present invention relates to the technical field of nanomaterial preparation, and in particular to a raspberry-shaped iron-cobalt nano-oxide material, a preparation method thereof, and an application thereof. Background Art

[0002] Iron-based metal-organic frameworks (MOFs) and Fe₃O₄ magnetic nanoparticles exhibit excellent adsorption and detection properties for antibiotics based on the Fenton reaction. Iron-based catalase sensors made from these materials can achieve a limit of detection (LOD) of up to 9 pM. However, these sensors require H₂O₂ catalysis for antibiotic detection, and their luminescence is unstable. Furthermore, the synthesis methods for these nanomaterials or MOFs are relatively fixed, typically involving hydrothermal, coprecipitation, and liquid-phase reduction methods, and detection methods are also complex. Enzyme-free fluorescent sensors, such as copper nanocluster sensors, have gained attention due to their wide linear range, low detection limit, high precision, green properties, and simple and rapid preparation. These fluorescent sensors, such as copper nanocluster sensors, do not require enzyme catalysis and are simple to synthesize. Existing technologies typically use single metal nanooxides as the sensing material for fluorescent sensors, but their stability in water is slightly inferior to that of bimetallic nanooxides, with bimetallic oxides such as iron and cobalt offering greater stability.

[0003] Antibiotics are a class of secondary metabolites produced by microorganisms (including bacteria, fungi, and actinomycetes) or higher plants and animals during their life processes that possess antipathogenic or other activities. They are chemical substances that can interfere with the developmental functions of other cells. Currently, antibiotics are widely used as therapeutic agents and growth promoters for animals. However, the widespread use and even abuse of antibiotics has led to large amounts of antibiotic residues in animal-derived foods, and bacterial resistance to antibiotics is a serious problem. Furthermore, excessive use of antibiotics can exacerbate environmental pollution and lead to various health and disease problems in humans, such as increased drug resistance, allergic reactions, genetic defects, and cancer.

[0004] Quinolone antibiotics are broad-spectrum antibiotics with excellent efficacy against a wide range of Gram-positive and Gram-negative bacterial infections and are widely used to treat bacterial infections in animals. However, these antibiotics can leave significant residual residues and can lead to a variety of adverse reactions, including the development of drug resistance and ineffectiveness of antibiotic treatment in humans with bacterial infections and gastrointestinal irritation. Numerous technologies have been explored to detect residual antibiotics. For example, optical sensors have become a research focus for antibiotic residue detection due to their simplicity, high sensitivity, and rapid detection. Optical technologies for quinolone detection are categorized by the optical detection method used, including colorimetry, chemiluminescence (CL), fluorescence, surface-enhanced Raman spectroscopy (SERS), and immunochromatography (ICA). Instrumental detection methods, such as high-performance liquid chromatography (HPLC) and chromatography-mass spectrometry (LC-MS / MS, HPLC-MS / MS), are highly sensitive, but require bulky and costly instrumentation and complex testing procedures. Traditional immunoassays, such as enzyme-linked immunosorbent assay (ELISA), offer moderate sensitivity and accuracy, but require extended detection times. For example, the patent application number 201911147668.8 discloses a method for colorimetric fluorescence detection of antibiotics using graphene-phase carbon nitride / gold nanoparticles. The patent uses negatively charged citric acid-modified gold nanoparticles (AuNPs) as colorimetric probes and positively charged graphene-phase carbon nitride nanosheets (g-C3N4) as fluorescent probes. The aptamer acts as a protective agent for AuNPs to prevent the aggregation of two differently charged nanomaterials. During the detection process, the aptamer specifically binds to the antibiotic and loses its protective ability for the gold nanoparticles, causing the two differently charged nanomaterials to attract each other due to positive and negative charges, causing AuNPs to aggregate on the g-C3N4 surface. By utilizing the surface plasmon resonance and fluorescence quenching properties of gold nanoparticles and the fluorescence properties of g-C3N4, the presence of antibiotics in the aqueous solution can be indicated by the solution color changing from red to blue and the fluorescence changing from strong to weak. Although the detection of this patent is intuitive, the synthesis operation is difficult, the cost is high, the detection sensitivity is low, and it has no practical application value.

[0005] Therefore, it is necessary to use bimetallic oxide nanomaterials such as iron and cobalt to prepare a fluorescent sensor with simple synthesis method, high sensitivity and enzyme-free detection of ciprofloxacin (CIP) and ofloxacin (OFL) in water. Summary of the Invention

[0006] In view of this, the present invention provides a method for preparing a raspberry-shaped iron-cobalt nano-oxide material, comprising the following steps:

[0007] (1) Mix a certain amount of iron salt, cobalt salt, urea, and sodium lauryl sulfate, then add deionized water and anhydrous ethanol, and stir until completely dissolved to obtain a reaction solution;

[0008] (2) placing the reaction solution in an environment of 100-120°C, heating with stirring for 4-8 hours, and centrifuging after the reaction is complete to obtain the reaction product;

[0009] (3) washing, drying, and calcining the reaction product to obtain a raspberry-shaped iron-cobalt nano-oxide material. Further, the iron salt in step (1) includes any one of ferric chloride, ferric nitrate, and ferric sulfate, and the cobalt salt includes any one of cobalt chloride, cobalt nitrate, and cobalt sulfate.

[0010] Furthermore, the molar ratio of the iron salt, cobalt salt, urea and sodium lauryl sulfate in step (1) is 0.4-0.8:0.8-1.6:16.8-22.4:9-12.

[0011] Furthermore, the volume ratio of deionized water to anhydrous ethanol in step (1) is 1-3:1.

[0012] Furthermore, in step (2), the temperature is controlled by an oil bath.

[0013] Furthermore, in step (2), the centrifugal speed is 4000-5000 r / min, and the centrifugal time is 5 min.

[0014] Furthermore, the drying temperature in step (3) is 60° C. and the drying time is 24 h.

[0015] Furthermore, the calcination temperature in step (3) is 400-500° C., and the calcination time is 2 h.

[0016] The present invention also provides a raspberry-shaped iron-cobalt nano-oxide material prepared according to the method, and application of the raspberry-shaped iron-cobalt nano-oxide material in fluorescence detection of ciprofloxacin and ofloxacin.

[0017] Compared with the prior art, the present invention has the following beneficial effects:

[0018] The present invention uses SDS as a soft template and prepares a raspberry-shaped iron-cobalt nano-oxide material after heating and calcining. The synthesis method is simple, and SDS is low in price, which can effectively reduce production costs and has good industrial application prospects.

[0019] The enzyme-free antibiotic fluorescence sensor provided by this invention not only successfully detects ciprofloxacin and ofloxacin, but also exhibits high sensitivity, rapid detection, selectivity, and good stability. The limits of detection (LODs) for ciprofloxacin and ofloxacin in fluorescence detection were 33.47 and 35.78 ng / mL, respectively. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 11 is the XRD pattern of R-CoFe2O4 ONMs and R-CoFe2O4 ONMPs prepared in Example 1 of the present invention.

[0021] Figure 2 4 is a scanning electron microscope image of R-CoFe2O4 ONMs and R-CoFe2O4 ONMPs prepared in Example 1 of the present invention.

[0022] Figure 3 These are the results of fluorescence detection of several antibiotics, including SDZ (sulfadiazine), MTR (tinidazole), TC (tetracycline), CIP (ciprofloxacin), and OFL (ofloxacin), by the R-CoFe2O4 ONMs system in Example 1 and the NiCoO2 system in Comparative Example 1, respectively.

[0023] Figure 4 This is a fluorescence detection diagram of CIP by R-CoFe2O4 ONMs prepared in Example 1.

[0024] Figure 5 This is a linear graph of fluorescence detection of OFL by R-CoFe2O4 ONMs prepared in Example 1.

[0025] Figure 6 3 is a comparison chart of fluorescence detection of the iron-cobalt oxide materials prepared in Example 1 and Example 2 at different molar ratios.

[0026] Figure 7 This is a schematic diagram of the fluorescence detection of OFL and CIP by R-CoFe2O4 ONMs prepared in Example 1. DETAILED DESCRIPTION

[0027] The present invention provides a method for preparing a raspberry-shaped iron-cobalt nano-oxide material, comprising the following steps:

[0028] (1) Mix a certain amount of iron salt, cobalt salt, urea, and sodium lauryl sulfate, then add deionized water and anhydrous ethanol, and stir until completely dissolved to obtain a reaction solution;

[0029] (2) placing the reaction solution in an environment of 100-120°C, heating with stirring for 4-8 hours, and centrifuging after the reaction is complete to obtain the reaction product;

[0030] (3) Washing, drying, and calcining the reaction product to obtain raspberry-shaped iron-cobalt nano-oxide material.

[0031] The raspberry-shaped iron-cobalt nano-oxide material prepared by the present invention has a chemical formula of CoFe2O4 and an XRD (X-ray diffractometer) PDF card number of JCPDS No. 22-1086. The material exhibits three characteristic diffraction peaks within the test range, located at 2θ = 36.7°, 42.5°, and 62.3°, corresponding to the (311), (400), and (440) crystal planes of the CoFe2O4 cubic system. Weak diffraction peaks appear at 36.7° and 62.3°, which are consistent with the standard structure of CoFe2O4 (JCPDS No. 22-1086). The material exhibits the same diffraction peaks as the standard card.

[0032] In some embodiments of the present invention, the iron salt in step (1) includes any one of ferric chloride, ferric nitrate, and ferric sulfate, and preferably, the iron salt is ferric chloride hexahydrate; the cobalt salt includes any one of cobalt chloride, cobalt nitrate, and cobalt sulfate, and preferably, the cobalt salt is cobalt dichloride hexahydrate.

[0033] In some embodiments of the present invention, the molar ratio of the iron salt, cobalt salt, urea and sodium lauryl sulfate in step (1) is in the range of 0.4-0.8:0.8-1.6:16.8-22.4:9-12, and the molar ratio of the iron salt, cobalt salt, urea and sodium lauryl sulfate in step (1) is 0.8:1.6:16.8:9.

[0034] In some embodiments of the present invention, the volume ratio of the deionized water and anhydrous ethanol in step (1) is 1-3:1, and the volume ratio of the deionized water and anhydrous ethanol in step (1) is 2:1.

[0035] In some embodiments of the present invention, the temperature of step (2) is controlled by an oil bath, and the reaction temperature of the reaction solution in step (2) is preferably 120°C.

[0036] In some embodiments of the present invention, the stirring speed in step (2) is 20-40 r / min, preferably, the stirring speed is 40 r / min.

[0037] In some embodiments of the present invention, in step (2), when the reaction solution changes from pink to light yellow, the reaction is complete and centrifugation is performed while hot.

[0038] In some embodiments of the present invention, the centrifugal speed in step (2) is 4000-5000 r / min and the centrifugal time is 5-10 min. Preferably, the centrifugal speed in step (2) is 5000 r / min and the centrifugal time is 5 min. 。

[0039] In some embodiments of the present invention, the drying temperature in step (3) is 60-80° C., and the drying time is 12-24 hours. Preferably, the drying temperature in step (3) is 60° C., and the drying time is 24 hours.

[0040] In some embodiments of the present invention, the calcination temperature in step (3) is 400-500° C., and the calcination time is 1-2 hours. Preferably, the calcination temperature in step (3) is 400° C., and the calcination time is 2 hours.

[0041] In some embodiments of the present invention, the heating rate in step (3) is 5-10°C / min, preferably, the heating rate is 10°C / min.

[0042] In some embodiments of the present invention, a tubular furnace is preferably used during the calcination process in step (3), and the vacuum degree is (-0.05) to (-0.1 MPa). Preferably, the vacuum degree of the calcination in step (3) is -0.1 MPa.

[0043] Principle of the Invention: The material is synthesized using a soft template method, with SDS acting as a template. During the homogeneous precipitation method for nanoparticle preparation, urea slowly generates ammonia upon heating in water, making the water alkaline. This slow alkalinity provides a milder reaction environment, avoiding the problem of large precipitation and aggregation caused by rapid reaction, thereby enabling the preparation of smaller nanoparticles. Fluorescence quenching is caused by electron transfer from the conduction band (CB) of R-CoFe2O4-ONMs to the lowest unoccupied molecular orbital (LUMO) of the electron-deficient analyte. This electron transfer is a well-established quenching mechanism, where the energy of the R-CoFe2O4-ONMs CB should be higher than that of the analyte's LUMO. A photoinduced electron transfer (PET) mechanism is proposed. Experiments show that the absorption spectra of OFL and CIP overlap significantly with the excitation spectrum of R-CoFe2O4-ONMs, indicating efficient FRET from R-CoFe2O4-ONMs to the analyte. Therefore, PET and competitive absorption processes play a significant role in fluorescence quenching. In addition, the raspberry-like morphology is also an important factor affecting the fluorescence inhibition of quinolone antibiotics.

[0044] The present invention also provides a raspberry-shaped iron-cobalt nano-oxide material prepared according to the method, and application of the raspberry-shaped iron-cobalt nano-oxide material in fluorescence detection of ciprofloxacin and ofloxacin.

[0045] To make the objectives, technical solutions, and advantages of the present invention more clear, the technical solutions of the present invention are described clearly and completely below. Obviously, the embodiments described are only some of the embodiments of the present invention, not all of them. All other embodiments derived by persons of ordinary skill in the art based on the embodiments of the present invention without inventive effort are also within the scope of protection of the present invention.

[0046] Unless otherwise specified, the experimental methods or test methods described in the following examples are all conventional methods; the raw materials and auxiliary agents, unless otherwise specified, are all obtained from conventional commercial channels or prepared by conventional methods.

[0047] Example 1

[0048] A method for preparing raspberry-shaped iron-cobalt nano-oxide material, comprising the following steps:

[0049] (1) Weigh 0.3790 g of cobalt chloride hexahydrate, 0.2160 g of ferric chloride hexahydrate, 3.4560 g of urea, and 1.0080 g of SDS into a 500 mL round-bottom flask, then add 160 mL of deionized water and 80 mL of anhydrous ethanol, and stir until completely dissolved to obtain a reaction solution;

[0050] (2) Place the flask containing the reaction solution in an oil bath at 120°C, reflux with stirring for 4 h at a stirring speed of 40 r / min. The solution changes from pink to light yellow. After the reaction is complete, centrifuge while hot at a speed of 5000 r / min for 5 min to obtain the reaction product.

[0051] (3) Wash twice with deionized water and once with anhydrous ethanol;

[0052] (4) drying in an oven at 60°C for 12 h to obtain raspberry-shaped cobalt iron nanooxide precursors (R-CoFe2O4ONMPs);

[0053] (5) The raspberry-shaped cobalt iron nano-oxide precursor was placed in a tube furnace, heated to 400°C at a heating rate of 10°C / min, vacuumed and calcined for 2 hours, and naturally cooled to obtain raspberry-shaped iron cobalt nano-oxide material (R-CoFe2O4 ONMs).

[0054] Fluorescence detection of CIP and OFL using the iron-cobalt nano-oxide material prepared in Example 1 is performed as follows:

[0055] (1) Fluorescence detection of CIP

[0056] The R-CoFe2O4 ONMs prepared in Example 1 and 4 ml of antibiotic CIP (ciprofloxacin) aqueous solution of different concentrations were added to 5 ml centrifuge tubes respectively. After ultrasonic treatment, a suspension with fluorescence emission was formed (about 20 min). -3 -10 -7 Fluorescence test was performed on a 100 mol / L CIP (ciprofloxacin) aqueous solution. The fluorescence test results are as follows Figure 4 As shown, from Figure 4 As can be seen, as the CIP (ciprofloxacin) concentration decreases, the fluorescence intensity (I) gradually increases, while the relative fluorescence intensity (I0-I) / I0 gradually decreases. This indicates that the R-CoFe2O4ONMs material also exhibits fluorescence inhibition for CIP (ciprofloxacin), and this inhibition, represented by the relative fluorescence intensity, decreases with decreasing antibiotic concentration. Based on the experimental results and the calculated LOD (LOD) of 33.47 ng / mL, this material demonstrates superior linearity for CIP (ciprofloxacin) detection compared to its OFL detection performance.

[0057] (2) Fluorescence detection of OFL

[0058] The R-CoFe2O4 ONMs prepared in Example 1 and 4 ml of antibiotic OFL (ofloxacin) aqueous solution of different concentrations were added to 5 ml centrifuge tubes respectively, and after ultrasonic treatment, a suspension with fluorescence emission was formed (about 20 min). -3 -10 -7 Fluorescence test was performed on OFL (Ofloxacin) aqueous solution of 10 mol / L. The fluorescence test results are as follows Figure 5 As shown, from Figure 5 It can be seen that as the concentration of OFL (ofloxacin) decreases, the fluorescence intensity (I) increases, and the relative fluorescence intensity (I0-I) / I0 gradually decreases. Under normal circumstances, as the concentration of antibiotics decreases, the fluorescence intensity will also decrease. However, when the R-CoFe2O4 ONMs material and antibiotics coexist, the material concentration remains unchanged. As the antibiotic concentration decreases, the fluorescence intensity instead shows an upward trend. It is concluded that the R-CoFe2O4 ONMs material has the characteristic of fluorescence inhibition for OFL, and the inhibition effect decreases as the antibiotic concentration decreases. When it reaches 10 -7 M order of magnitude, the inhibitory effect is close to zero. According to the experimental results and the formula LOD=3σ / k sp (σ and k sp The LOD of OFL (ofloxacin) was calculated to be 35.78 ng / mL.

[0059] Figure 7This is a schematic diagram of the fluorescence detection of OFL and CIP by R-CoFe2O4 ONMs prepared in Example 1. Figure 7 As shown, the aqueous solution of the iron-cobalt nanooxide material exhibits fluorescence, measured by a fluorescence spectrophotometer. This fluorescence intensity, I0, is measured. When CIP and OFL aqueous solutions are added at certain concentrations, the fluorescence intensity (I0) gradually increases as the antibiotic concentration decreases, while the relative fluorescence intensity (I0-I) / I0 decreases. This indicates that the R-CoFe2O4 ONMs material exhibits fluorescence inhibition against CIP (ciprofloxacin), and this inhibitory effect, represented by the relative fluorescence intensity, decreases with decreasing antibiotic concentration.

[0060] Figure 1 The XRD patterns of R-CoFe2O4 ONMs and R-CoFe2O4 ONMPs prepared in Example 1 of the present invention are shown in FIG. Figure 1 It can be seen that there are three characteristic diffraction peaks in the test range, which are located at 2θ=36.7°, 42.5° and 62.3°, corresponding to the (311), (400) and (440) crystal planes of the CoFe2O4 cubic system. The weak diffraction peaks appearing at 36.7° and 62.3° are consistent with the standard structure of CoFe2O4 (JCPDS No.22-1086). The material has the same diffraction peaks as the standard card, indicating that the prepared product is CoFe2O4. In addition, Figure 1 It can be seen that the XRD pattern of R-CoFe2O4 ONMPs lacks the peak corresponding to the oxide, indicating that R-CoFe2O4 ONMPs were successfully prepared into high-purity R-CoFe2O4ONMs by calcination, and its main component is CoFe2O4.

[0061] Figure 2 Ad are scanning electron micrographs of R-CoFe2O4 ONMs and R-CoFe2O4 ONMPs prepared in Example 1 of the present invention, Figure 2 ab show the SEM images of R-CoFe2O4 ONMs. Figure 2 It can be seen from ab that the structure of the R-CoFe2O4 ONMs material is a raspberry-shaped three-dimensional porous structure. The porous layer characteristics of R-CoFe2O4 ONMs give it larger pores and specific surface area, and faster electron transfer rate, which is beneficial to the fluorescence absorption of the material. Figure 2 cd shows the SEM images of R-CoFe2O4ONMPs, Figure 2As can be seen from the cd, R-CoFe2O4 ONMPs exhibit a raspberry-like structure composed of a large number of nearly spherical nanoparticles. Comparing the electron micrographs of the precursor and oxide prepared in Example 1, it can be seen that the nanoparticles of this material are stacked and interconnected in a two-dimensional plane, and the overall structure exhibits a three-dimensional laminated structure.

[0062] Example 2

[0063] A method for preparing an iron-cobalt nano-oxide material, comprising the following steps:

[0064] (1) Weigh 0.3240 g of cobalt chloride hexahydrate, 0.2844 g of ferric chloride hexahydrate, 1.0080 g of urea, and 3.4560 g of SDS into a 500 mL round-bottom flask, then add 180 mL of deionized water and 60 mL of ethanol, and stir until completely dissolved to obtain a reaction solution;

[0065] (2) Place the flask containing the reaction solution in an oil bath and heat at 100°C for 4 hours under continuous magnetic stirring to obtain a light yellow product. After the reaction is complete, centrifuge while hot at a speed of 5000 r / min for 5 minutes to obtain the reaction product;

[0066] (3) Wash twice with ultrapure water and once with anhydrous ethanol;

[0067] (4) drying in an oven at 60°C for 24 h to obtain an iron-cobalt nano-oxide precursor;

[0068] (5) The cobalt-nickel nano-oxide precursor is placed in a tube furnace, heated to 400° C. at a heating rate of 5° C. / min, evacuated, and calcined for 2 h, and cooled naturally to obtain an iron-cobalt nano-oxide material.

[0069] The iron-cobalt nano-oxide material prepared in Example 2 and 4 ml of antibiotic CIP (ciprofloxacin) aqueous solution of different concentrations were added to 5 ml centrifuge tubes respectively, and after ultrasonic treatment, a suspension with fluorescence emission was formed (about 20 min). -4 -10 -6 The fluorescence test was carried out with a CIP (ciprofloxacin) aqueous solution of 10 mol / L. -4 -10 -6 mol / L CIP (ciprofloxacin) aqueous solution fluorescence test was compared to obtain Figure 6 , Figure 6 a and Figure 6b are the R-CoFe2O4-ONMs systems of iron-cobalt nano-oxide materials prepared in Example 2 and Example 1, respectively. Under the adsorption of two bimetallic oxides obtained by two different metal feed molar ratios, the CIP was detected from 10 -4 -10 -6 The fluorescence intensity change diagram of M, by comparison, we can see that 10 -4 At M concentration Figure 6 The peak fluorescence intensity of a is at 6.4×10 4 , Figure 6 The fluorescence intensity of b is less than 3×10 4 It can be concluded that in the R-CoFe2O4-ONMs system, under the molar ratio of Example 1, the prepared material has a higher efficiency in suppressing CIP fluorescence.

[0070] Comparative Example 1

[0071] A method for preparing a nickel-cobalt nano-oxide material, comprising the following steps:

[0072] (1) Weigh 0.3809 g of cobalt chloride hexahydrate, 0.1914 g of nickel chloride hexahydrate, 1.0080 g of urea, and 3.4560 g of SDS into a 500 mL round-bottom flask, then add 160 mL of deionized water and 80 mL of anhydrous ethanol, and stir until completely dissolved to obtain a reaction solution;

[0073] (2) Place the flask containing the reaction solution in an oil bath at 120°C, reflux with stirring for 4 h at a stirring speed of 40 r / min. The solution changes from pink to light green. After the reaction is complete, centrifuge while hot at a speed of 5000 r / min for 5 min to obtain the reaction product.

[0074] (3) Wash twice with deionized water and once with anhydrous ethanol;

[0075] (4) drying in an oven at 60°C for 4 h to obtain a cobalt-nickel nano-oxide precursor;

[0076] (5) The cobalt-nickel nano-oxide precursor is placed in a tube furnace, heated to 400° C. at a heating rate of 5° C. / min, evacuated, and calcined for 2 h, and cooled naturally to obtain a cobalt-nickel nano-oxide material (NiCoO2).

[0077] Take 4 mg of each of the raspberry-shaped iron-cobalt nano-oxide material (R-CoFe2O4 ONMs) prepared in Example 1 and the cobalt-nickel nano-oxide material prepared in Comparative Example 1, and mix them with 4 ml of 10% ethanol. -4mol / L aqueous solutions containing different types of antibiotics including SDZ (sulfadiazine), MTR (tinidazole), TC (tetracycline), CIP (ciprofloxacin), and OFL (ofloxacin) were mixed in 5 ml centrifuge tubes to prepare multiple mixed solutions. After 20 min of sonication, a suspension with fluorescent emission was formed. 3 ml of the suspension was removed and placed in 5 ml four-sided transparent cuvettes, and the fluorescence intensity was measured on a fluorescence spectrophotometer.

[0078] The method of the present invention for measuring fluorescence data is as follows: under room temperature conditions, a fluorescence spectrum is obtained with an emission slit of 5 nm, an excitation slit of 10 nm, and an emission wavelength of 300-400 nm.

[0079] The results are as follows Figure 3 As shown in ab, Figure 3 It can be seen from ab that the fluorescence inhibition efficiency of the R-CoFe2O4 ONMs system prepared in Example 1 for quinolone antibiotics (CIP and OFL) is above 75%, and the fluorescence inhibition rate for other antibiotics is below 70%. The fluorescence inhibition efficiency of the NiCoO2 system prepared in Comparative Example 1 for various antibiotics is below 75%. It is concluded that one of the factors affecting the selective detection of quinolone antibiotics by the R-CoFe2O4 ONMs system is the Fe element. The redox reaction generates hydroxyl radicals (·OH), which lead to the fluorescence quenching of the antibiotic.

[0080] The above is only a preferred embodiment of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the principles of the present invention. These improvements and modifications should also be regarded as within the scope of protection of the present invention.

Claims

1. Application of a raspberry-shaped iron-cobalt nano-oxide material in fluorescence detection of ciprofloxacin or ofloxacin, characterized in that: The preparation method of the raspberry-shaped iron-cobalt nano-oxide material comprises the following steps: (1) Mix a certain amount of iron salt, cobalt salt, urea and sodium lauryl sulfate, then add deionized water and anhydrous ethanol, and stir until completely dissolved to obtain a reaction solution; (2) Place the reaction solution in an environment of 100-120°C, heat with stirring for 4-8 hours, and centrifuge after the reaction is complete to obtain the reaction product; (3) washing, drying, and calcining the reaction product to obtain a raspberry-shaped iron-cobalt nano-oxide material; The iron salt in step (1) includes any one of ferric chloride, ferric nitrate, and ferric sulfate; The molar ratio of the iron salt, cobalt salt, urea and sodium lauryl sulfate in step (1) is 0.4-0.8:0.8-1.6:16.8-22.4:9-12; The volume ratio of deionized water to anhydrous ethanol in step (1) is 1-3:1; The calcination temperature in step (3) is 400-500°C, and the calcination time is 2h.

2. The use of the raspberry-shaped iron-cobalt nano-oxide material in fluorescence detection of ciprofloxacin or ofloxacin according to claim 1, characterized in that: The cobalt salt includes any one of cobalt chloride, cobalt nitrate and cobalt sulfate.

3. The use of the raspberry-shaped iron-cobalt nano-oxide material in fluorescence detection of ciprofloxacin or ofloxacin according to claim 1, characterized in that: In step (2), the temperature is controlled by an oil bath.

4. The use of the raspberry-shaped iron-cobalt nano-oxide material in fluorescence detection of ciprofloxacin or ofloxacin according to claim 1, characterized in that: The centrifugal speed in step (2) is 4000-5000 r / min, and the centrifugal time is 5 min.

5. The use of the raspberry-shaped iron-cobalt nano-oxide material in fluorescence detection of ciprofloxacin or ofloxacin according to claim 1, characterized in that: The drying temperature in step (3) is 60° C. and the drying time is 24 h.

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