Fluorescent probe, preparation thereof and application of fluorescent probe in detection of glyphosate in water

Abstract

The invention discloses a fluorescent probe, preparation thereof and application of the fluorescent probe in detection of glyphosate in water. The fluorescent probe provided by the invention is constructed by self-assembling symmetric tetramethyl cucurbit [6] uril and guest molecules E as raw materials. The fluorescent probe is a novel self-assembly body, is simple in preparation method, can be used for qualitatively or quantitatively detecting glyphosate in water, and has the characteristics of high sensitivity, high selectivity, low cost, simplicity in sample treatment, convenience in operation and rapidness in determination.

Description

Technical Field

[0001] This invention relates to a fluorescent probe, its preparation and application, and particularly to a fluorescent probe, its preparation and application in detecting glyphosate in water. Background Technology

[0002] Glyphosate (GLYP), chemically known as N-(methyl)glycine phosphate, is a highly effective, broad-spectrum, and non-selective pesticide, making it one of the most produced and used pesticides globally, with high levels of residues in the environment. These glyphosate residues are released into environmental water, soil, and even the food chain, posing a significant threat to ecosystems and human health. In 2015, the International Agency for Research on Cancer (IARC) classified glyphosate as a "possible human carcinogen." Furthermore, glyphosate carries the risk of inducing or enhancing chronic degeneration of the kidneys and liver.

[0003] Typical traditional methods for detecting glyphosate include high-performance liquid chromatography (HPLC) and gas chromatography (GC). These methods are highly sensitive; however, they require expensive equipment, cumbersome sample preparation, a large amount of reagents, and specialized technicians. This makes them time-consuming for routine analysis of pesticides in food and environmental samples and unsuitable for on-site detection.

[0004] Fluorescent detection technology has advantages such as high sensitivity, fast response speed, and the ability to visualize and monitor in real time. Therefore, there is an urgent need to construct a suitable fluorescent probe to detect residual glyphosate.

[0005] The purpose of this invention is to provide a fluorescent probe, its preparation, and its application in the detection of glyphosate in water. The fluorescent probe of this invention is a novel self-assembled structure with a simple preparation method. It can be used for qualitative or quantitative detection of glyphosate in water and features high sensitivity, high selectivity, low cost, simple sample processing, convenient operation, and rapid determination.

[0006] One of the technical solutions of the present invention: A method for preparing a fluorescent probe is provided, which involves self-assembly of a symmetrical tetramethyl hexa-membered cucurbit ring and a guest molecule E as raw materials. The chemical structural formula of compound E is as follows: .

[0007] Preferably, the aforementioned method for preparing the fluorescent probe includes the following specific steps: (1) Take the symmetrical tetramethyl hexamembered cucurbit ring, dissolve it in water, and prepare solution A; (2) Take the guest molecule E, dissolve it in water, and prepare solution B; (3) Mix solution A and solution B and react at room temperature to obtain probe solution.

[0008] Preferably, in the aforementioned method for preparing the fluorescent probe, the molar ratio of the symmetrical tetramethyl hexamembered cucurbit ring to the guest molecule E is 1:1.

[0009] Preferably, in the aforementioned method for preparing the fluorescent probe, the preparation process of the guest molecule E is as follows: .

[0010] Preferably, in the aforementioned method for preparing the fluorescent probe, the concentration of the symmetrical tetramethyl hexamembered cucurbitacin in solution A is 1.0 × 10⁻⁶. -3 mol / L.

[0011] Preferably, in the aforementioned method for preparing the fluorescent probe, the concentration of guest molecule E in solution B is 1.0 × 10⁻⁶. - 3 mol / L.

[0012] A fluorescent probe is provided, which is prepared according to the method described in one of the foregoing technical solutions.

[0013] This invention provides an application of the fluorescent probe described in the second of the foregoing technical solutions in the detection of glyphosate in water.

[0014] A method for detecting glyphosate in water is provided, which uses the fluorescent probe described in the second of the aforementioned technical solutions as a detection reagent.

[0015] A fluorescent reagent for detecting glyphosate in water is provided, which is prepared by the fluorescent probe described in the second technical solution above and water.

[0016] 1. The fluorescent probe prepared by this invention is a novel supramolecular fluorescent probe based on cucurbit rings, which can detect glyphosate in water.

[0017] 2. The preparation method of the fluorescent probe of the present invention is simple and easy to implement.

[0018] 3. The fluorescent probe provided by this invention can not only qualitatively detect glyphosate in water and determine whether the aqueous solution contains glyphosate, but also quantitatively detect glyphosate in water and determine the concentration of glyphosate in the aqueous solution, based on the different changes in fluorescence intensity.

[0019] 4. The method for detecting glyphosate in water using the fluorescent probe of the present invention has the advantages of high sensitivity, high selectivity, low cost, simple sample processing, convenient operation, and rapid determination. Attached Figure Description

[0020] Figure 1 The image shows the proton NMR spectrum of guest molecule E.

[0021] Figure 2This is the carbon NMR spectrum of guest molecule E.

[0022] Figure 3 This is the mass spectrum of guest molecule E.

[0023] Figure 4 The diagram shows the nuclear magnetic titration and inclusion pattern of the symmetrical tetramethyl hexa-membered cucurbit ring (TMeQ[6]) and guest molecule E.

[0024] Figure 5 Different concentrations of glyphosate were used in fluorescent probe solutions (2.0 × 10⁻⁶). -5 The graph shows the concentration-fluorescence change of the fluorescent probe solution (2.0 × 10⁻⁶ mol / L) in aqueous solution, where (a) is the concentration-fluorescence change of the fluorescent probe solution (2.0 × 10⁻⁶ mol / L). -5 (a) Fluorescence spectrum changes of glyphosate (mol / L) coexisting with different concentrations of glyphosate; (b) Standard curve of glyphosate concentration-fluorescence intensity change value ΔI obtained from the fluorescence spectrum changes.

[0025] Figure 6 The concentration obtained in this invention is 2.0 × 10⁻⁶. -5 The image shows the detection results of adding 23 different pesticides to a mol / L fluorescent probe standard solution.

[0026] Figure 7 The graph shows the fluorescence color changes of 23 pesticides under ultraviolet light (a) and the interference of different pesticides on glyphosate in the presence of glyphosate (b). Detailed Implementation

[0027] The present invention will be further described below with reference to embodiments, but these embodiments are not intended to limit the scope of the invention.

[0028] Embodiments of the present invention Example 1

[0029] The preparation method of each reagent in the analytical method of this invention is as follows: (1) Weigh out a symmetrical tetramethyl hexacyclic cucurbitacin (TMeQ[6]), dissolve it in deionized water, and prepare a solution with a concentration of 1×10 -3 mol / L TMeQ[6] solution.

[0030] (2) Weigh out guest molecule E, dissolve it in deionized water, and prepare a solution with a concentration of 1×10⁻⁶. -3 A mol / L solution of the compound N-Br.

[0031] (3) Preparation of other pesticide solutions: Accurately weigh the required analytical grade standards of various pesticides, dissolve them in deionized water, and prepare a solution with a concentration of 1×10⁻⁶. -2 Other pesticide standard solutions at mol / L.

[0032] The preparation method of the above-mentioned guest molecule E is as follows: Example 2

[0033] One method for preparing the fluorescent probe is as follows: (1) Take the symmetrical tetramethyl hexacyclic cucurbitacin (TMeQ[6]) and prepare a solution with a concentration of 1.0×10 -3 A mol / L TMeQ[6] solution; (2) Take guest molecule E and prepare a solution with a concentration of 1.0 × 10⁻⁶. -3 A solution of guest molecule E at a concentration of mol / L; (3) A solution of symmetrical tetramethyl hexacyclic cucurbita (TMeQ[6]) and guest molecule E was mixed at a molar ratio of 1:1 and reacted at room temperature to prepare a solution with a concentration of 2×10 -5 mol / L fluorescent probe standard solution. Example 3

[0034] The method for detecting glyphosate using the fluorescent probe prepared in Example 2: (1) Determination of the standard curve: Take a quartz fluorescence cuvette and add 3000 μL of a solution with a concentration of 2.0 × 10⁻⁶. -5 Add 1.8 μL of a mol / L probe standard solution to a solution with a concentration of 1.0 × 10⁻⁶ mol / L. -2 A glyphosate solution of mol / L was mixed thoroughly, and its fluorescence emission spectrum was measured at a fixed excitation wavelength of 483 nm. Following the same procedure, 1.8 μL of a 1.0 × 10⁻⁶ mol / L solution was continuously added to the above 3000 μL probe solution. -2 A series of fluorescence curves were measured for glyphosate at a constant excitation wavelength of 483 nm. The titration was stopped when the value on the ordinate of the fluorescence curve changed slowly, yielding the following result: Figure 5 The fluorescence spectrum change diagram shown ( Figure 5 a). By plotting the glyphosate concentration on the x-axis and the difference (ΔI) between the initial emission intensity (I0) of the fluorescent probe at 582 nm and the fluorescence intensity (I) after adding different concentrations of glyphosate solution, a standard curve of glyphosate concentration versus fluorescence intensity change ΔI can be obtained. Figure 5 b) Based on the slope of the standard curve and the 11 standard solutions of the probe (fluorescent probe concentration 2.0 × 10⁻⁶), -5 Based on the mean of blank test results (mol / L), the detection limit of glyphosate solution was calculated to be 1.07 × 10⁻⁶. -6 mol / L.

[0035] (2) Sample testing: Take an aqueous solution containing glyphosate, but with an unknown concentration, add the prepared fluorescent probe standard solution to it, and observe at an excitation wavelength of 483 nm. If a significant decrease in fluorescence intensity is observed at 582 nm, it indicates that the water sample contains glyphosate.

[0036] Take an aqueous solution that does not contain glyphosate, add the prepared fluorescent probe standard solution to it, and observe at an excitation wavelength of 483 nm. If no significant change in fluorescence intensity is observed at 582 nm, it indicates that the water sample does not contain glyphosate or the content is below the detection limit of the probe. Example 4

[0037] The detection performance of this fluorescent probe for glyphosate: (1) Selectivity Add 3000 μL of fluorescent probe standard solution (2.0 × 10⁻⁻⁶) to the solution. 5 In a quartz fluorescence cuvette containing 1.0 × 10⁻² mol / L of different pesticide standard solutions, 60 μL of each solution was added. After thorough mixing, the fluorescence emission spectra of the solutions were measured at a fixed excitation wavelength of 483 nm. Figure 6 As shown, only the sample containing glyphosate exhibited significant fluorescence quenching (i.e., a sharp decrease in fluorescence intensity) at 582 nm. In contrast, other pesticides did not cause significant changes in fluorescence at this wavelength. This result strongly demonstrates that the probe can selectively identify glyphosate.

[0038] (2) Anti-interference capability Take a quartz fluorescence cuvette and add 3000 μL of a solution with a concentration of 2.0 × 10⁻⁶. -5 First, add 60 μL of a 1.0 × 10 mol / L fluorescent probe standard solution. -2 Add 60 μL of a 1.0 × 10⁻⁶ mol / L glyphosate standard solution to the solution. -2 Other pesticide standard solutions at mol / L were mixed and their fluorescence emission spectra were measured at a fixed excitation wavelength of 483 nm. The results are as follows: Figure 7 As shown, the presence of other pesticides in conjunction with glyphosate does not significantly affect the selectivity of the probe for glyphosate.

[0039] The above description is merely a preferred embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any equivalent substitutions or modifications made by those skilled in the art within the scope of the technology disclosed in the present invention, based on the technical solution and inventive concept of the present invention, should be covered within the scope of protection of the present invention.

Claims

1. A method for preparing a fluorescent probe, characterized by: is prepared by using symmetrical tetramethyl six-membered cucurbituril and guest molecule E as raw materials to self-assemble. 。 2. The method for preparing the fluorescent probe according to claim 1, characterized in that, The specific steps of the method are as follows: (1) Take symmetrical tetramethyl six-membered cucurbituril, dissolve in water to prepare solution A; (2) Take guest molecule E, dissolve in water to prepare solution B; (3) Mix solution A and solution B, and react at room temperature to obtain the probe solution.

3. The method of claim 1 or 2, wherein: The mixing molar ratio of the symmetrical tetramethyl six-membered cucurbituril and the guest molecule E is 1:

1.

4. The method of claim 1 or 2, wherein: The preparation process of the guest molecule E is as follows: 。 5. The method for preparing the fluorescent probe according to claim 2, characterized in that: The concentration of symmetrical tetramethyl six-membered cucurbituril in the solution A is 1.0 x 10 -3 mol / L.

6. The method of claim 2, wherein: The concentration of guest molecules E in the solution B is 1.0 x 10 -3 mol / L.

7. A fluorescent probe characterized in that: Prepared according to the method of any one of claims 1-6.

8. The application of the fluorescent probe of claim 7 in detecting glyphosate in water.

9. A method of detecting glyphosate in water, characterized by: The fluorescent probe of claim 7 is used as a detection reagent for detection.

10. A fluorescent reagent for detecting glyphosate in water, characterized by: The fluorescent probe of claim 7 and water are configured.

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