A method for preparing and applying a visual metronidazole antibiotic test strip

Abstract

This invention belongs to the field of antibiotic detection technology, specifically relating to a method for preparing and applying a visual metronidazole antibiotic test strip. The DUT-52@R6G composite material synthesized in this application exhibits high selectivity for metronidazole, accurately detecting the presence of metronidazole in aqueous solutions containing multiple antibiotics. Furthermore, this composite material is loaded onto a test strip, which can directly determine the presence of metronidazole in a sample through color changes, and its concentration can be determined based on the color intensity, exhibiting highly efficient visualization. Simultaneously, due to the high selectivity of the DUT-52@R6G composite material for metronidazole, it also possesses high sensitivity. Moreover, this test strip does not require expensive instruments and reagents, effectively reducing detection costs.

Description

Technical Field

[0001] This invention belongs to the field of antibiotic detection technology, specifically relating to a method for preparing and applying a visual metronidazole antibiotic test strip. Background Technology

[0002] Since A. Fleming's discovery of penicillin in 1929, numerous antibiotics have been produced and used worldwide to treat diseases in humans, animals, and plants caused by pathogens. Consequently, large quantities of antibiotics are released into the environment through household wastewater, hospitals, pharmaceutical companies, sewage treatment plants, and emissions from aquaculture and livestock farms. Currently, antibiotics are present in high concentrations in surface water, groundwater, soil, sediments, and biotas in almost every part of the world, leading to their classification as a new type of pollutant. Furthermore, the misuse of antibiotics, viewing them as a panacea, has resulted in increased antibiotic resistance and heightened health risks.

[0003] Since their invention, antibiotics have been widely used in agriculture, animal husbandry, food, and veterinary medicine due to their excellent therapeutic effects. At the same time, their growth-promoting effects on animals have also been discovered. However, this has been accompanied by global health problems caused by antibiotic overuse. With the rapid increase in global meat demand, the global use of veterinary antibiotics is projected to increase by 67% from 2010 to 2030. Multiple studies have shown that the amount of antibiotics used in pig farms is much higher than in other agricultural sectors. China is the largest consumer and producer of antibiotics, and its overuse is particularly serious. Metronidazole is one of the most widely used antibiotics; although it has good efficacy, its overuse can lead to adverse reactions and environmental pollution. Its extensive use in agriculture, animal husbandry, fisheries, and aquaculture also poses a threat to the environment.

[0004] Metronidazole (MDZ), also known as Femtozole, is a nitroimidazole antibiotic. Since being designated as the first-line drug for combating anaerobic bacteria by the World Health Organization in 1978, metronidazole has been widely used in the medical field. However, this drug is also a source of concern due to its potential side effects, such as carcinogenicity, teratogenicity, mutagenicity, and genotoxicity. In particular, metronidazole residues in food may pose a potential threat to human health. For example, bean sprouts, a common vegetable, may experience anaerobic bacterial growth due to improper storage methods during planting, transportation, and preservation, thus affecting their shelf life and appearance. Some unscrupulous merchants may use antibiotics such as metronidazole to increase the yield and extend the shelf life of bean sprouts. However, according to the national standard GB31650-2019 "National Food Safety Standard Maximum Residue Limits for Veterinary Drugs in Food," metronidazole must not be detected in animal-derived foods.

[0005] Furthermore, the development and application of metronidazole antibiotic test strips are also of great significance in the agricultural sector. Metronidazole, as a broad-spectrum antibiotic, is commonly used in agricultural production to prevent and treat animal diseases, promoting animal growth and increasing yields. However, the residue of metronidazole in animal-derived foods has been a major concern. Animal-derived foods such as meat, poultry, and eggs are important components of people's daily diets. However, due to the overuse of antibiotics during animal husbandry, metronidazole and other antibiotics remain in animals, subsequently entering the human body through the food chain, posing a potential threat to human health. Therefore, developing an efficient and visual metronidazole antibiotic test strip is of great importance.

[0006] In the current field of antibiotic detection, physicochemical detection methods are commonly used. Antibiotic molecules contain different functional groups, which possess specific reactions or properties, allowing us to determine the antibiotic content. Physicochemical detection methods include high-performance liquid chromatography (HPLC), thin-layer chromatography (TLC), gas chromatography (GC), mass spectrometry (MS), and coupled techniques, such as GC-MS, TLC-MS, LC-MS, LC-NMR, and SFC-MC. These methods offer high sensitivity for qualitative and quantitative analysis of antibiotics, but their disadvantages include expensive equipment, complex and cumbersome pretreatment, high skill requirements for technicians, long analysis cycles, and the need for complex processing of measurement results, resulting in less visual representation. These limitations restrict their widespread use. Therefore, developing efficient and visual materials for antibiotic detection, especially those suitable for selective sensing and high-efficiency light-emitting devices, has significant scientific and practical value. Summary of the Invention

[0007] Based on the above objectives, the first technical solution of this application discloses a method for preparing DUT-52@R6G composite material, which includes encapsulating Rhodamine 6G (R6G) in a nanocage of DUT-52 material under hydrothermal conditions via a one-pot reaction method to form DUT-52@R6G composite material.

[0008] Furthermore, the hydrothermal conditions are 80-120℃, pressure 1-5 MPa, and reaction time 12-60 h.

[0009] Furthermore, the DUT-52@R6G composite material was prepared according to the above preparation method.

[0010] The second technical solution of this application discloses the application of the above-mentioned DUT-52@R6G composite material in the detection of metronidazole. By loading the composite material onto test paper, it is used for the detection of metronidazole in aqueous solution.

[0011] The third technical solution of this application discloses a metronidazole antibiotic test strip loaded with DUT-52@R6G composite material.

[0012] The fourth technical solution of this application discloses a method for preparing the above-mentioned metronidazole antibiotic test strip, which involves dissolving the DUT-52@R6G composite material and then impregnating it with filter paper, followed by natural drying.

[0013] Furthermore, the metronidazole antibiotic test strip prepared by the above preparation method and its application in detecting metronidazole in aqueous solution.

[0014] The beneficial effects of this invention are as follows:

[0015] The DUT-52@R6G composite material synthesized in this application exhibits high selectivity for metronidazole, enabling accurate detection of metronidazole in aqueous solutions containing multiple antibiotics. Furthermore, this composite material is loaded onto a test strip, which directly determines the presence of metronidazole in a sample through color changes, and the concentration can be roughly estimated based on the color intensity, offering highly efficient visualization. Simultaneously, due to the high selectivity of the DUT-52@R6G composite material for metronidazole, it exhibits high sensitivity. Moreover, this test strip does not require expensive instruments and reagents, effectively reducing detection costs. Attached Figure Description

[0016] Appendix Figure 1 Here is a structural diagram of the prepared DUT-52@R6G composite material;

[0017] Appendix Figure 2 Powder diffraction, thermogravimetric analysis, and scanning electron microscopy images of DUT-52 and DUT-52@R6G;

[0018] Appendix Figure 3 The fluorescence spectrum of DUT-52@R6G for detecting antibiotics;

[0019] Appendix Figure 4 State diagrams of composite materials and metronidazole test strips in different environments;

[0020] Appendix Figure 5 Graph showing changes in metronidazole test strips before and after the addition of metronidazole;

[0021] Appendix Figure 6 The images shown are of the actual products in question. Detailed Implementation

[0022] The present invention will now be described in detail with reference to embodiments and accompanying drawings. However, it should be understood that the embodiments and drawings are for illustrative purposes only and do not constitute any limitation on the scope of protection of the present invention. All reasonable modifications and combinations included within the inventive spirit of the present invention fall within the scope of protection of the present invention.

[0023] Example 1: Preparation of DUT-52@R6G composite material

[0024] This includes encapsulating Rhodamine 6G (R6G) in nanocages of DUT-52 material under hydrothermal conditions via a one-pot reaction at 80-120℃, 1-5 MPa, and a reaction time of 12-60 h, to form DUT-52@R6G composite material.

[0025] It is understood that in this embodiment, the reaction temperature of 80-120°C includes any temperature within this range, such as 80°C, 90°C, 100°C, 110°C, 120°C, etc., and the reaction time of 12-60h includes any time within this range, such as 12h, 24, 36, 48, 60h, etc.

[0026] It should be noted that in this embodiment, the preparation method of the DUT-52 material is as follows: ZrCl4 (1.03 mmol, 230 mg) and 20 mL of N,N'-dimethylformamide (DMF) are added to a polytetrafluoroethylene reactor, sonicated for 5 min, then 2,6-naphthalenediacetic acid (216 mg 1 mmol) is added, and sonicated for 5 min to obtain the final product. The one-pot reaction method involves directly adding Rhodamine 6G (R6G) for encapsulation after preparing the DUT-52 material, without the need for two separate steps. Figure 1 As shown, the specific method is as follows: After the aforementioned reaction, add 3 mL of acetic acid and 600 mg of Rhodamine 6G dye in the same manner, and then sonicate for 15 min. Place in an oven (120℃) and heat for 24 h, then remove and cool to room temperature to obtain the final product.

[0027] Understandably, after obtaining the DUT-52@R6G composite material, in order to ensure that the material surface is free of impurities, the material can be washed three times with DMF, then washed three times with anhydrous ethanol, and centrifuged. The collected sample is then dried at 120℃ for 12 hours to remove surface impurities.

[0028] In this specific embodiment, the target DUT-52@R6G composite material is preferably obtained by reacting at 120°C for 50 hours for experimental use.

[0029] The structure, stability, and morphology of the target DUT-52@R6G composite material were analyzed by X-ray diffraction (XRD), thermogravimetric analysis (TGA), and scanning electron microscopy (SEM). The results are as follows: Figure 2 As shown, the obtained DUT-52@R6G exhibits high thermal stability, namely the blue emission of DUT-52 at 435 nm and the characteristic emission of R6G dye at 568 nm, with a quantum yield as high as 77.8%. This demonstrates its potential application as a highly selective and sensitive probe for the detection of metronidazole. This study provides new possibilities for the application of metronidazole antibiotic detection in fluorescence sensing. This product investigates the fluorescence quenching effects of different antibiotics on DUT-52@R6G composite materials. Metronidazole (MDZ), an antibiotic with a significant fluorescence quenching effect on DUT-52@R6G composite materials, was selected from 13 common antibiotics. It was then mixed sequentially with the remaining 12 antibiotics (RDZ, ODZ, DTZ, FZD, NFZ, NF-κB, SDZ, SMZ, FFC, THI, CAP, and LVX), and the selectivity of the DUT-52@R6G composite material to the antibiotics was tested. Figure 3 Through chart analysis, the antibiotic with the best selectivity—metronidazole—was selected, and then a metronidazole test strip was made.

[0030] Example 2: Preparation of Metronidazole Antibiotic Test Strip

[0031] Weigh 50 mg of DUT-52@R6G sample and dissolve it in 3 mL of DMF (dimethylformamide). Sonicate the sample for 20 min, then soak filter paper in the solution and sonicate for another 10 min. After drying, the metronidazole antibiotic test strip is obtained.

[0032] It should be noted that in this embodiment, the applicant used water, methanol, ethanol, and DMF (dimethylformamide) as solvents for the DUT-52@R6G sample. By observing the fluorescence intensity of the obtained test strips under ultraviolet light, it was found that the test strips obtained using DMF as a solvent had the best performance. Subsequently, using 3 mL of DMF as a solvent, 10 mg, 20 mg, and 50 mg of sample were weighed and dissolved in the solvent to obtain test strips. It was found that the test strip quality was optimal when the sample to solvent addition ratio was 50 mg / 3 mL. Ultrasound is beneficial for sample dissolution, allowing the sample to better impregnate the test strip. Therefore, ultrasonic dissolution is preferred in this embodiment.

[0033] Example 3: Detection of metronidazole antibiotic using the developed test strip:

[0034] (1) Prepare metronidazole solutions of different concentrations: dilute high-concentration (1000 μg / mL) metronidazole antibiotic solution to prepare low-concentration metronidazole antibiotic solutions, and prepare metronidazole antibiotic solutions of different concentrations (500 μg / mL, 250 μg / mL, 150 μg / mL, 100 μg / mL, 75 μg / mL, 50 μg / mL, 25 μg / mL, 10 μg / mL);

[0035] (2) Using the metronidazole test strip prepared by the above-mentioned optimal research and development route, 50 μL of metronidazole antibiotics of different concentrations were added to the test strip and the fluorescence quenching effect was observed under ultraviolet light.

[0036] (3) Conclusion: Through comparative analysis and observation under ultraviolet light, it was found that metronidazole solutions of different concentrations could quench the fluorescence of the metronidazole antibiotic test strip, and the 10 μg / mL metronidazole solution had a particularly significant quenching effect on the fluorescence of the test strip. Figure 4-6 Therefore, metronidazole antibiotic test strips also perform well in the application of trace detection of metronidazole.

[0037] The embodiments described above are some, but not all, of the embodiments of this application. The detailed description of the embodiments of this application is not intended to limit the scope of the claimed application, but merely to illustrate selected embodiments. All other embodiments obtained by those skilled in the art based on the embodiments of this application without inventive effort are within the scope of protection of this application.

Claims

1. The application of a DUT-52@R6G composite material in the detection of metronidazole, characterized in that, The composite material was loaded onto filter paper for the detection of metronidazole in aqueous solution. The preparation method of the DUT-52@R6G composite material is as follows: Rhodamine 6G is encapsulated in the nanocage of DUT-52 material by a one-pot reaction under hydrothermal conditions to form the DUT-52@R6G composite material. The hydrothermal conditions are 80-120 ℃, pressure is 1-5 MPa, and reaction time is 12-60 h.

2. The application of a metronidazole antibiotic test strip in detecting metronidazole in aqueous solution, characterized in that, The metronidazole antibiotic test strip is obtained by dissolving the DUT-52@R6G composite material described in claim 1, impregnating it with filter paper, and then air-drying it naturally.

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