A method for detecting Fe(CN)6 in water 3- Supramolecular fluorescent probe and preparation method and application method thereof

Abstract

The invention discloses a method for detecting Fe(CN)6 in water. 3‑ The invention discloses a supramolecular fluorescent probe and a preparation method and an application method thereof, wherein the supramolecular fluorescent probe is assembled by using the supramolecular interaction between a seven-membered cucurbit ring and 1,3,5-tri[4-(1-butylpyridinium-1-ium-4-yl)phenyl]benzene, and can be applied to Fe(CN)6 3‑ ions for qualitative and quantitative detection, the detection steps are: 1) prepare the probe standard solution; 2) add different concentrations of Fe(CN)6 3‑ 3) Add the sample to be tested to the probe standard solution, and perform qualitative and quantitative detection of whether the sample to be tested contains Fe(CN)6 based on the fluorescence change graph and the standard curve. 3‑ The present invention has the characteristics of low analysis cost, simple operation, low detection limit, high sensitivity and rapidity.

Description

Technical Field

[0001] The invention belongs to the technical field of analytical chemistry and specifically relates to a method for detecting Fe(CN) in water. 6 3- Supramolecular fluorescent probe and its preparation method and application method. Background Art

[0002] Potassium ferrocyanide (K 3 [Fe{CN} 6 ]) is a red solid crystal. Although it is stable at room temperature, it is easily decomposed into highly toxic cyanide (KCN, HCN) by light after burning or in aqueous solution. When low-toxic cyanide complex salts such as ferrocyanate are discharged into surface water in large quantities, they can also decompose and release a considerable amount of free cyanide after exposure to sunlight and other conditions, leading to poisoning and death of aquatic organisms. In addition, even if the concentration of cyanide is very low, it is very toxic to organisms. For example, cyanide ions can quickly bind to trivalent iron ions in oxidative cytochrome oxidase, preventing it from being reduced to divalent iron ions, interrupting the oxidation process of transferring electrons, and tissue cells cannot use oxygen in the blood, causing internal asphyxiation. The central nervous system is most sensitive to hypoxia, so the brain is damaged first, leading to central respiratory failure and death. Therefore, it is necessary to develop a simple, rapid, sensitive and accurate and effective method to qualitatively and quantitatively detect Fe(CN) 6 3- The analytical methods are crucial to both the environment and food safety.

[0003] Among the numerous analytical methods, the fluorescent probe method has attracted extensive attention due to its simple technology, high sensitivity, rapidity, and applicability to biological environments. However, due to the aggregation-induced fluorescence quenching effect, traditional fluorescent probes can only be used at relatively low concentrations. If used in large doses, organic fluorophores can easily form aggregates. The above disadvantages limit its practical application in environmental detection research. The fluorescent probe constructed by this technology is an AIE probe, which can overcome this application disadvantage and better detect Fe(CN) in water environments. 6 3- Compared with the current search document technology (CN115477761A), the preparation and separation process of the hinged 14-membered cucurbit ring used is relatively complicated. The seven-membered cucurbit ring used in the present invention is easier to obtain, and the detection limit of the present invention is lower than that of the search document technology, reaching 2.5×10 -8 mol / L. In addition, under the irradiation of portable ultraviolet light, it can be seen that the addition of Fe(CN) 6 3- Afterwards, the fluorescence of the fluorescent probe of the present invention is directly quenched, and the fluorescence change effect is more obvious. Summary of the invention

[0004] The purpose of this patent is to provide a method for preparing a supramolecular fluorescent probe based on a seven-membered cucurbit ring and to use it to simply, portablely and rapidly detect the pollutant Fe(CN) in water. 6 3- .

[0005] The technical solution of the present invention:

[0006] The first object of the present invention is to provide: a method for detecting Fe(CN) in water 6 3- The supramolecular fluorescent probe is assembled by utilizing the supramolecular interaction between a seven-membered cucurbitacin (Q[7] for short) and 1,3,5-tri[4-(1-butylpyridin-1-ium-4-yl)phenyl]benzene (BTPY for short).

[0007] Furthermore, the method is used to detect Fe(CN) in water. 6 3- The molecular formula of the supramolecular fluorescent probe is: 3C 42 H 42 N 28 O 14 @C 51 H 54 N 3 Br 3 , the structure is as follows:

[0008]

[0009] in,

[0010] The second object of the present invention is to provide: the aforementioned method for detecting Fe(CN) in water 6 3- The preparation method of the supramolecular fluorescent probe comprises the following steps:

[0011] (1) Weigh the seven-membered cucurbitacin ring and dissolve it in water to prepare a concentration of 1.0×10 -4 mol / L seven-membered cucurbit ring solution;

[0012] (2) Weigh the compound BTPY and dissolve it in water to prepare a concentration of 1.0×10 -3 mol / L BTPY solution;

[0013] (3) The seven-membered cucurbitacin solution and the compound BTPY solution are mixed in a certain molar ratio and reacted at room temperature for 10-20 minutes to obtain a supramolecular fluorescent probe.

[0014] The third object of the present invention is to provide a method for detecting Fe(CN) in water using a supramolecular fluorescent probe 6 3- The method of content is as follows:

[0015] (1) Take the supramolecular fluorescent probe and dilute it with secondary water at pH = 7 to obtain a concentration of 1.0×10 -5 mol / L probe standard solution;

[0016] (2) Add different concentrations of Fe(CN) to the probe standard solution 6 3- The aqueous solution was mixed evenly, and the fluorescence emission spectrum was measured with a fixed excitation wavelength of 297 nm to draw a fluorescence intensity change curve at an emission wavelength of 454 nm;

[0017] (3) Calculate the fluorescence intensity change curve of step (2) by adding Fe(CN) 6 3- The standard curve can be obtained by the intensity change ΔI of the fluorescence emission spectrum of the aqueous solution before and after at 454nm;

[0018] (4) Add the sample to be tested to the probe standard solution, and then observe whether the fluorescence intensity at 454 nm is significantly weakened under the excitation wavelength of 297 nm, and calculate the Fe(CN) in the sample to be tested based on the standard curve. 6 3- or add the probe standard solution into the fluorescence colorimetric tube, then add the sample to be tested and mix well, then observe the color change of the solution in the fluorescence colorimetric tube under 365nm ultraviolet light.

[0019] In step (4), if the fluorescence intensity is significantly reduced after the sample to be tested is added, it indicates that the sample to be tested contains Fe(CN) 6 3- ; If no significant change occurs, it means that the sample to be tested does not contain Fe(CN) 6 3- Or the content is below the detection limit.

[0020] In step (4), if the color of the solution in the fluorescence colorimetric tube is quenched under 365nm ultraviolet light, it indicates that the test sample contains Fe(CN) 6 3- ; If no significant change occurs, it means that the sample to be tested does not contain Fe(CN) 6 3- Or the content is below the detection limit.

[0021] Beneficial Effects of the Invention

[0022] The supramolecular fluorescent probe prepared by the present invention is a novel supramolecular probe based on cucurbitacin, which can detect Fe(CN) 6 3-The detection method of the present invention has the advantages of high sensitivity, simple sample processing, convenient operation, and rapid determination. At the same time, the Fe(CN) 6 3- Quantitative detection of concentration.

[0023] The concentration obtained in the present invention is 1.0×10 -5 mol / L fluorescent probe standard solution was added with different concentrations of Fe(CN) 6 3- The solution was tested and the test results were as follows Figure 4 Use this figure to draw the standard curve. Figure 4 The detection limit was calculated to be 2.5×10 -8 mol / L. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Attached Figure 1 It is a structural formula of a seven-membered cucurbit ring and a new type of phenyl terphenyl derivative, namely 1,3,5-tri[4-(1-butylpyridin-1-ium-4-yl)phenyl]benzene (abbreviated as BTPY).

[0025] Attached Figure 2 The BTPY solvent effect diagram and the fluorescence spectra of the seven-membered cucurbit ring and BTPY. Among them: (a) and (b) are the fluorescence curves and fitting curves of BTPY in different proportions of water and tetrahydrofuran mixed solutions; (c) is a series of solution fluorescence trend diagrams prepared by the molar ratio method; (d) is the Job method of BTPY and the seven-membered cucurbit ring processed by the origin software.

[0026] Attached Figure 3 The NMR titration and action mode diagram of the seven-membered cucurbitacin and BTPY. Among them, (a) is BPTY; (b) is a mixture of BTPY and seven-membered cucurbitacin at a molar ratio of 1:1.5; (c) is a mixture of BTPY and seven-membered cucurbitacin at a molar ratio of 1:3.

[0027] Attached Figure 4 As a supramolecular probe for Fe(CN) 6 3- Specific selection, titration fluorescence graph and linear fitting graph. Among them, (a) is the probe for Fe(CN) 6 3- Specific selective fluorescence spectrum; (b) is the probe to Fe(CN) under 365nm ultraviolet light irradiation 6 3- Color diagram of other anion solutions; (c) probe to Fe(CN) 6 3- Titration fluorescence diagram; (d) is the fluorescence intensity of the solution at 454nm and Fe(CN)6 3- Concentration (0~40×10 -7 M) Linear fitting diagram. DETAILED DESCRIPTION

[0028] The present invention will be further described below in conjunction with the embodiments, but they are not intended to limit the present invention.

[0029] Embodiments of the present invention

[0030] Embodiment 1:

[0031] The preparation method of each reagent in the analytical method of the present invention is:

[0032] (1) Accurately weigh an appropriate amount of seven-membered cucurbitacin ring, dissolve it in secondary water, sonicate it, transfer it to a 100 mL volumetric flask, and make up the volume to a concentration of 1.0 × 10 -4 mol / L seven-membered cucurbitacin solution.

[0033] (2) Accurately weigh an appropriate amount of compound BTPY, dissolve it in secondary water, transfer it to a 10 mL volumetric flask and make up the volume to a concentration of 1.0 × 10 -3 mol / L compound BTPY solution.

[0034] (3)Fe(CN) 6 3- Preparation of standard solution:

[0035] Accurately weigh the required K 3 [Fe{CN} 6 ] was dissolved in a secondary aqueous solution at pH = 7 to obtain a concentration of 1.0 × 10 -3 mol / LFe(CN) 6 3- Standard solution.

[0036] Embodiment 2:

[0037] A method for detecting Fe(CN) in water 6 3- The preparation method of the supramolecular fluorescent probe is as follows:

[0038] (1) Take the seven-membered cucurbitacin ring and prepare a mixture with a concentration of 1.0×10 -4 mol / L seven-membered cucurbitacin solution.

[0039] (2) Take compound BTPY and prepare a solution with a concentration of 1.0×10 -3 mol / L BTPY solution.

[0040] (3) The seven-membered cucurbitacin solution in step (1) and the BTPY solution in step (2) are mixed in a molar ratio of 3:1 between the seven-membered cucurbitacin and the compound BTPY, and the mixture is allowed to react at room temperature for 10 minutes to obtain the supramolecular fluorescent probe.

[0041] Embodiment three:

[0042] A method for detecting Fe(CN) in water 6 3- The preparation method of the supramolecular fluorescent probe is as follows:

[0043] (1) Accurately weigh an appropriate amount of seven-membered cucurbitacin ring to prepare a solution with a concentration of 1.0×10 -4 mol / L seven-membered cucurbitacin solution.

[0044] (2) Accurately weigh an appropriate amount of compound BTPY to obtain a concentration of 1.0×10 -3 mol / L BTPY solution.

[0045] (3) The seven-membered cucurbitacin solution in step (1) and the BTPY solution in step (2) are mixed in a molar ratio of 3:1 between the seven-membered cucurbitacin and the compound BTPY, and the mixture is allowed to react at room temperature for 20 minutes to obtain a supramolecular fluorescent probe.

[0046] Embodiment 4:

[0047] A method for detecting Fe(CN) in water by using the supramolecular fluorescent probe prepared in Example 2 6 3- The method for qualitative and quantitative detection of ions is:

[0048] (1) Determination of standard curve:

[0049] Take 10 10mL volumetric flasks and add 200μL of 1.0×10 -3 mol / L of compound BTPY solution and 6000 μL of 1.0×10 -4 mol / L seven-membered cucurbitacin solution was mixed evenly to form a probe, and then 1.0×10 -3 mol / LFe(CN) 6 3- The standard solution of 4.0μL, 6.0μL, 8.0μL, 10.0μL, 12.0μL, 14.0μL, 16.0μL, 18.0μL, 20.0μL, 22.0μL was made up to volume with a secondary aqueous solution of pH=7 and then shaken for use; the fluorescence emission spectrum was determined with a fixed excitation wavelength of 297nm, and Fe(CN) 6 3- The concentration is the horizontal axis, and the fluorescence emission intensity of the probe at 454 nm (I0 ) and adding different concentrations of Fe(CN) 6 3- The difference in fluorescence emission intensity (I 0 -I) as the ordinate, and draw a standard curve. The slope s of the standard curve and the standard deviation σ of 11 blank values ​​were used to calculate the fluorescence probe to Fe(CN) 6 3- The detection limit is 3σ / s.

[0050] (2) Sample testing:

[0051] Take Fe(CN) 6 3- However, when the fluorescent probe standard solution is added to the aqueous solution with unknown concentration, the fluorescence intensity at 454nm is significantly weakened under the excitation wavelength of 297nm, indicating that the water sample contains Fe(CN) 6 3- .

[0052] Take Fe(CN) 6 3- The standard solution of fluorescent probe is added into the aqueous solution, and no obvious change of fluorescence intensity is observed at 454nm under the excitation wavelength of 297nm, which means that the water sample does not contain Fe(CN) 6 3- The fluorescent probe standard solution is prepared by diluting the probe to a concentration of 1.0×10 -5 mol / L.

[0053] Embodiment five:

[0054] A method for detecting Fe(CN) in water by using the supramolecular fluorescent probe prepared in Example 3 6 3- The method for qualitative and quantitative detection of ions is:

[0055] (1) Determination of standard curve:

[0056] Take the probe of Example 3 and dilute it with secondary water of pH=7 to a concentration of 1.0×10 -5 mol / L, which is the standard solution of fluorescent probe; take a quartz fluorescence cuvette and add a concentration of 1.0×10 -5 mol / L fluorescent probe solution 3000 μL, then accurately add 1.0×10 -3 mol / LFe(CN) 6 3-6.0 μL of the standard solution was mixed evenly, and the fluorescence emission spectrum was determined at a fixed excitation wavelength of 297 nm. According to the above operation, a certain amount of 6.0 μL Fe(CN) was continuously added to the above 3000 μL probe solution. 6 3- Standard solution, and at an excitation wavelength of 297nm, a series of fluorescence curves are measured until the vertical coordinate value of the fluorescence curve changes slowly, then the titration operation can be stopped. 6 3- The concentration is the horizontal axis, and the fluorescence emission intensity of the probe at 454nm is compared with the addition of different concentrations of Fe(CN) 6 3- The difference of fluorescence emission intensity was taken as the ordinate to obtain the standard curve. The slope s of the standard curve and the standard deviation σ of 11 blank values ​​were used to calculate the fluorescence probe detection of Fe(CN). 6 3- The detection limit is 3σ / s.

[0057] (2) Sample testing:

[0058] Take Fe(CN) 6 3- However, when the fluorescent probe standard solution is added to an aqueous solution of unknown concentration and the fluorescence intensity at 454nm is significantly weakened at an excitation wavelength of 297nm, it indicates that the water sample contains Fe(CN) 6 3- , no obvious change in fluorescence intensity was observed at 454 nm, indicating that the water sample did not contain Fe(CN) 6 3- Or the content is lower than the detection limit of the probe.

[0059] The above description is only a preferred specific implementation manner of the present invention, but the protection scope of the present invention is not limited thereto. Any technician familiar with the technical field can make equivalent replacements or changes according to the technical solutions and inventive concepts of the present invention within the technical scope disclosed by the present invention, which should be covered by the protection scope of the present invention.

Claims

1. A method for detecting Fe(CN)6 in water 3- The supramolecular fluorescent probe is characterized by: It is prepared from an aqueous solution of a seven-membered cucurbitacin and an aqueous solution of 1,3,5-tris[4-(1-butylpyridin-1-ium-4-yl)phenyl]benzene; The method for detecting Fe(CN)6 in water 3- The molecular formula of the supramolecular fluorescent probe is: 3C 42 H 42 N 28 O 14 @C 51 H 54 N3Br3, the structure is as follows: in, .

2. The method for detecting Fe(CN)6 in water according to claim 1 3- The method for preparing a supramolecular fluorescent probe is characterized by: The specific method is as follows: 1) Take the seven-membered cucurbitacin ring and dissolve it in water to obtain a concentration of 1×10 -4 mol / L solution A; 2) Take compound BTPY and dissolve it in water to obtain a concentration of 1×10 -3 mol / L solution B; the BTPY is 1,3,5-tri[4-(1-butylpyridin-1-ium-4-yl)phenyl]benzene; 3) Mix solution A and solution B, and then react them at room temperature to obtain Fe(CN)6 for detecting water. 3- Supramolecular fluorescent probe.

3. The method for detecting Fe(CN)6 in water according to claim 2 3- The method for preparing a supramolecular fluorescent probe is characterized by: In step 3), when the solution A and the solution B are mixed, the molar ratio of the seven-membered cucurbitacin to BTPY in the mixture is 3:

1.

4. A method for detecting Fe(CN)6 in water using the supramolecular fluorescent probe described in claim 1 3- The method is characterized in that: Here are the steps: 1) Take the supramolecular fluorescent probe and dilute it with secondary water at pH = 7 to a concentration of 1×10 -5 mol / L probe standard solution; 2) Add different concentrations of Fe(CN)6 to the probe standard solution prepared in step 1) 3- The aqueous solution was placed for 10-20min, and then the fluorescence emission spectrum was measured at a fixed excitation wavelength of 297 nm, and the fluorescence probe solution containing different Fe(CN)6 3- The fluorescence intensity change curve and fitting curve at the laser wavelength are plotted according to the change value ΔI of the fluorescence emission spectrum intensity at 454 nm before and after the aqueous solution; 3) Take the probe standard solution and add it to the sample to be tested, then use 297nm as the fixed excitation wavelength, observe the change of fluorescence emission spectrum intensity at 454nm and calculate the change value of fluorescence emission spectrum intensity ΔI, and then use the fitting curve to calculate the Fe(CN)6 3- Quantitative analysis of the content.

5. Detection of Fe(CN)6 in water by using the supramolecular fluorescent probe according to claim 4 3- The method is characterized in that: In step 3), when the fluorescence emission spectrum intensity at 454 nm is significantly weakened after the test sample aqueous solution is added, it indicates that the test sample aqueous solution contains Fe(CN)6 3- If no significant change occurs, it indicates that the aqueous solution of the sample to be tested does not contain Fe(CN)6 3- Or the content is below the detection limit.

6. A method for detecting Fe(CN)6 in water using the supramolecular fluorescent probe described in claim 1 3- The method is characterized in that: Here are the steps: 1) Take the supramolecular fluorescent probe and dilute it with secondary water at pH = 7 to a concentration of 1×10 -5 mol / L probe standard solution; 2) Add different concentrations of Fe(CN)6 to the probe standard solution prepared in step 1) 3- The aqueous solution was placed for 10-20min, and then the fluorescence emission spectrum was measured at a fixed excitation wavelength of 297 nm, and the fluorescence probe solution containing different Fe(CN)6 3- The fluorescence intensity change curve and fitting curve at the laser wavelength are plotted according to the change value ΔI of the fluorescence emission spectrum intensity at 454 nm before and after the aqueous solution; 3) Take a fluorescence colorimetric tube, add the probe standard solution and the sample to be tested into it in turn, mix them evenly, then irradiate the fluorescence colorimetric tube containing the mixture under a 365 nm ultraviolet lamp to observe whether the solution is quenched.

7. Detection of Fe(CN)6 in water by using the supramolecular fluorescent probe according to claim 6 3- The method is characterized in that: In step 3), when the color of the solution in the fluorescence colorimetric tube is quenched after the sample to be tested is added, it indicates that the sample to be tested contains Fe(CN)6 3- If no significant change occurs, it indicates that the sample to be tested does not contain Fe(CN)6 3- Or the content is below the detection limit.

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