Supramolecular fluorescent probe based on cucurbituril and preparation and application thereof

Abstract

This invention discloses a supramolecular fluorescent probe based on a helical fourteen-membered cucurbit ring, its preparation, and its application. The supramolecular fluorescent probe of this invention is prepared from a helical fourteen-membered cucurbit ring and 1-(7-carboxyheptyl)-4-(pyrene-1-yl)pyridin-1-onium, and can be used to detect Hg in aqueous solutions. 2+ The fluorescent probe of this invention is a novel fluorescent probe based on a helical fourteen-membered cucurbit ring. Its preparation method is simple, and it is used for detecting Hg in aqueous solutions. 2+ It is easy to operate, highly sensitive, has a fast response time, and is visible to the naked eye, making it well worth widespread application.

Description

Technical Field

[0001] This invention relates to a fluorescent probe, its preparation and application, and in particular to a supramolecular fluorescent probe based on a helical fourteen-membered cucurbit ring, its preparation and application. Background Technology

[0002] Heavy metals, accumulated in nature and released through human production activities, pose a serious threat to the natural ecological environment and human health. Mercury ions (Hg) are a prime example. 2+ As a highly toxic heavy metal ion, Hg is classified as a Class A water pollutant. The World Health Organization (WHO) allows a permitted level of Hg in drinking water. 2+ The ion concentration must be below 0.001 mg / L (5 μM).

[0003] The reason is Hg 2+ The extreme toxicity of Hg is primarily produced by methylmercury through bacterial activity. It can accumulate permanently in organisms through the food chain, leading to central nervous system dysfunction, Hunter-Russell syndrome, and Minamata disease, seriously threatening human life and health. Therefore, Hg in the aquatic environment... 2+ Detection and quantitative evaluation are crucial.

[0004] To date, methods such as inductively coupled plasma mass spectrometry (ICP-MS), atomic fluorescence spectrometry (AFS), atomic absorption spectrometry (AAS), and inductively coupled plasma optical emission spectrometry (ICP-OES) have been used to specifically detect Hg in environmental and biological samples. 2+ Ions. Despite the advantages of these methods in terms of high precision and sensitivity, their high cost and complexity limit their application to Hg. 2+ The practicality of the test.

[0005] Therefore, it is necessary to develop a rapid and effective method for detecting Hg. 2+ The methods and reagents used are crucial for environmental monitoring and the maintenance of life and health. Among the many different analytical methods, supramolecular fluorescent probes have attracted much attention due to their unique advantages such as simple technology, high sensitivity, non-invasiveness, fast reaction time, and "naked-eye" visualization. Summary of the Invention

[0006] To address the aforementioned technical problems, this invention provides a supramolecular fluorescent probe based on a helical fourteen-membered cucurbit ring, its preparation, and its application. This invention's fluorescent probe is a novel fluorescent probe based on a helical fourteen-membered cucurbit ring, and its preparation method is simple. It is used for detecting Hg in aqueous solutions. 2+ It is easy to operate, highly sensitive, has a fast response time, and is visible to the naked eye, making it well worth widespread application.

[0007] One of the technical solutions of the present invention:

[0008] Provided is a supramolecular fluorescent probe based on a tetranuclear cucurbituril, which has the following chemical structure:

[0009]

[0010] wherein, is a helical tetranuclear cucurbituril.

[0011] The second technical solution of the present application is:

[0012] Provided is a preparation method of the aforementioned supramolecular fluorescent probe based on a helical tetranuclear cucurbituril, which is prepared from a helical tetranuclear cucurbituril and 1-(7-carboxyheptyl)-4-(pyrene-1-yl)pyridine-1-ium as raw materials.

[0013] Preferably, the preparation method of the aforementioned supramolecular fluorescent probe based on a helical tetranuclear cucurbituril specifically comprises the following steps:

[0014] (1) Take the helical tetranuclear cucurbituril, add water to dissolve, and prepare solution A;

[0015] (2) Take 1-(7-carboxyheptyl)-4-(pyrene-1-yl)pyridine-1-ium, add water to dissolve, and prepare solution B;

[0016] (3) Mix solution A and solution B, and a supramolecular fluorescent probe can be obtained through a self-assembly reaction.

[0017] Preferably, the preparation method of the aforementioned supramolecular fluorescent probe based on a helical tetranuclear cucurbituril, the concentration of the helical tetranuclear cucurbituril in solution A is 0.5*10 -3 -1.5*10 -3 mol / L.

[0018] Preferably, the preparation method of the aforementioned supramolecular fluorescent probe based on a helical tetranuclear cucurbituril, the concentration of 1-(7-carboxyheptyl)-4-(pyrene-1-yl)pyridine-1-ium in solution B is 0.5*10 -3 -1.5*10 -3 mol / L.

[0019] Preferably, the preparation method of the aforementioned supramolecular fluorescent probe based on a helical tetranuclear cucurbituril, when solution A and solution B are mixed, the molar ratio of the helical tetranuclear cucurbituril and 1-(7-carboxyheptyl)-4-(pyrene-1-yl)pyridine-1-ium is 1:2.

[0020] Preferably, the preparation method of the aforementioned supramolecular fluorescent probe based on a helical tetranuclear cucurbituril, the self-assembly reaction in step (3) is carried out at room temperature.

[0021] The third technical solution of the present application is:

[0022] This provides a supramolecular fluorescent probe based on a helical fourteen-membered cucurbit ring for detecting Hg in aqueous solution. 2+ Applications.

[0023] The fourth technical solution of the present invention:

[0024] This invention provides a method for detecting Hg in aqueous solution using the aforementioned supramolecular fluorescent probe. 2+ The method includes the following steps:

[0025] (1) Take the supramolecular fluorescent probe and add water to prepare a solution with a concentration of 1×10⁻⁶. -5 -3×10 -5 mol / L fluorescent probe standard solution;

[0026] (2) Add the aqueous solution to be tested to the fluorescent probe standard solution prepared in step (1), let it stand for 5-10 minutes, and then perform fluorescence emission spectrum determination at a fixed excitation wavelength of 385nm, and plot the change curve of fluorescence intensity at the corresponding excitation wavelength of 521nm.

[0027] (3) By comparing the change curve plotted in step (2) with the change value ΔI of the fluorescence emission spectrum intensity at 521 nm, the concentration of Hg in the water can be determined. 2+ Conduct testing.

[0028] Preferably, the aforementioned supramolecular fluorescent probe is used to detect Hg in aqueous solution. 2+ The method involves determining whether the fluorescence emission spectrum at 521 nm is significantly weakened before and after the addition of the test aqueous solution. If so, it indicates the presence of Hg in the test aqueous solution. 2+ Conversely, it does not contain Hg. 2+ .

[0029] The beneficial effects of this invention are:

[0030] 1. The supramolecular fluorescent probe of the present invention is a novel supramolecular fluorescent probe prepared using a helical fourteen-membered cucurbit ring and 1-(7-carboxyheptyl)-4-(pyrene-1-yl)pyridine-1-onium as raw materials.

[0031] 2. The supramolecular fluorescent probe of the present invention is prepared by an aqueous solution of a helical fourteen-membered cucurbit ring and an aqueous solution of 1-(7-carboxyheptyl)-4-(pyrene-1-yl)pyridine-1-onium, which is simple to prepare and has low cost.

[0032] 3. The supramolecular fluorescent probe of the present invention can be used to detect Hg in aqueous solution. 2+ At that time, it can sensitively and quickly detect Hg in aqueous solution. 2+ The detection limit is as low as 0.177 μM, far below the WHO's allowable limit for Hg in drinking water. 2+The concentration is 5.0 μM; and the results are visible to the naked eye, making the operation very easy.

[0033] In summary, the fluorescent probe of this invention is a novel fluorescent probe based on a helical fourteen-membered cucurbit ring. Its preparation method is simple, and it is suitable for detecting Hg in aqueous solutions. 2+ It is easy to operate, highly sensitive, has a fast response time, and is visible to the naked eye, making it well worth widespread application. Attached Figure Description

[0034] Appendix Figure 1 The structural formulas and schematic diagrams of the helical fourteen-membered cucurbit ring (hereinafter referred to as tQ

[14] ) and 1-(7-carboxyheptyl)-4-(pyrene-1-yl)pyridine-1-onium (hereinafter referred to as Pyr-O) are shown below.

[0035] Appendix Figure 2 The fluorescence spectrum of Pyr-O was gradually obtained by adding tQ

[14] in amounts ranging from 0.0, 0.1... to 2.0 equivalents;

[0036] Appendix Figure 3 Job's diagram of supramolecular fluorescent probe (hereinafter referred to as Pyr-O@tQ

[14] );

[0037] Appendix Figure 4 The fluorescence lifetime spectra of Pyr-O and Pyr-O@tQ

[14] are shown;

[0038] Appendix Figure 5 SEM image of the Pyr-O@tQ

[14] assembly;

[0039] Appendix Figure 6 The fluorescence quantum yield spectra of Pyr-O and Pyr-O@tQ

[14] are shown.

[0040] Appendix Figure 7 The NMR titration and inclusion pattern diagrams of tQ

[14] and Pyr-O are shown; where (i) Pyr-O; (ii) Pyr-O: tQ

[14] = 10:1; (iii) Pyr-O: tQ

[14] = 10:2; (iv) Pyr-O: tQ

[14] = 10:4; (iv) Pyr-O: tQ

[14] = 2:1.

[0041] Appendix Figure 8 The fluorescence spectrum of Pyr-O@tQ

[14] for the specific recognition of 18 cations;

[0042] Appendix Figure 9 Add different concentrations of Hg to the Pyr-O@tQ

[14] solution 2+ Fluorescence titration spectrum of ions in solution;

[0043] Appendix Figure 10Schematic diagram of the detection of Hg 2+ by using a smart phone

[0044] Figure 1 Figure 11 Fluorescence titration detection limit of Pyr-O@tQ

[14] when added into a solution containing Hg 2+

[0045] Figure 2 Figure 12 Fluorescence contrast chart of Pyr-O@tQ for specific recognition of 18 kinds of cations (irradiated under 365 nm ultraviolet light)

[0046] Figure 3 Figure 13 Anti-interference column chart of Pyr-O@tQ

[14] for 18 kinds of perchlorate cations Hg 2+ em (λ em = 521 nm).

[0047] Figure 4 Figure 14 Column chart of Pyr-O@tQ

[14] for specific recognition of 18 kinds of perchlorate cations (λ em = 521 nm). DETAILED DESCRIPTION

[0048] The present application will be further described below in conjunction with examples, but shall not be construed as a limitation on the present application.

[0049] Embodiments of the present application

[0050] Example 1

[0051] The preparation of the supramolecular fluorescent probe based on the spiral fourteen-membered cucurbituril is as follows:

[0052] (1) Take the spiral fourteen-membered cucurbituril, add water to dissolve, and prepare solution A with a concentration of 1 × 10 -3 mol / L;

[0053] (2) Take 1-(7-carboxyheptyl)-4-(pyrene-1-yl) pyridine-1-ium, add water to dissolve, and prepare solution B with a concentration of 1 × 10 -3 mol / L;

[0054] (3) Mix solution A and solution B, control the molar ratio of the spiral fourteen-membered cucurbituril and 1-(7-carboxyheptyl)-4-(pyrene-1-yl) pyridine-1-ium to be 1:2, and obtain the supramolecular fluorescent probe by self-assembly reaction at room temperature for a moment by standing.

[0055] Example 2

[0056] The preparation of the supramolecular fluorescent probe based on the spiral fourteen-membered cucurbituril is as follows:

[0057] (1) Take the spiral fourteen-membered cucurbituril, add water to dissolve, configure the concentration of solution A is 0.5×10 -3 mol / L;

[0058] (2) Take 1-(7-carboxyheptyl)-4-(pyrene-1-yl) pyridine-1-ium, add water to dissolve, configure the concentration of solution B is 0.5×10 -3 mol / L;

[0059] (3) Mix solution A and solution B, control the molar ratio of spiral fourteen-membered cucurbituril and 1-(7-carboxyheptyl)-4-(pyrene-1-yl) pyridine-1-ium is 1:2, at room temperature by standing self-assembly reaction for a moment, the supramolecular fluorescent probe can be obtained.

[0060] Example 3

[0061] The preparation of supramolecular fluorescent probe based on spiral fourteen-membered cucurbituril, the steps are as follows:

[0062] (1) Take the spiral fourteen-membered cucurbituril, add water to dissolve, configure the concentration of solution A is 0.8×10 -3 mol / L;

[0063] (2) Take 1-(7-carboxyheptyl)-4-(pyrene-1-yl) pyridine-1-ium, add water to dissolve, configure the concentration of solution B is 0.8×10 -3 mol / L;

[0064] (3) Mix solution A and solution B, control the molar ratio of spiral fourteen-membered cucurbituril and 1-(7-carboxyheptyl)-4-(pyrene-1-yl) pyridine-1-ium is 1:2, at room temperature by standing self-assembly reaction for a moment, the supramolecular fluorescent probe can be obtained.

[0065] Example 4

[0066] The preparation of supramolecular fluorescent probe based on spiral fourteen-membered cucurbituril, the steps are as follows:

[0067] (1) Take the spiral fourteen-membered cucurbituril, add water to dissolve, configure the concentration of solution A is 1.2×10 -3 mol / L;

[0068] (2) Take 1-(7-carboxyheptyl)-4-(pyrene-1-yl) pyridine-1-ium, add water to dissolve, configure the concentration of solution B is 1.2×10 -3 mol / L;

[0069] (3) mixing solution A and solution B, controlling the molar ratio of the spiral fourteen-membered cucurbituril and 1-(7-carboxyheptyl)-4-(pyrene-1-yl) pyridine-1-ium to be 1:2, and obtaining the supramolecular fluorescent probe by self-assembly reaction at room temperature for a few moments through standing.

[0070] Example 5

[0071] The preparation of the supramolecular fluorescent probe based on the spiral fourteen-membered cucurbituril is as follows:

[0072] (1) taking the spiral fourteen-membered cucurbituril, dissolving in water to prepare solution A with a concentration of 1.5×10 -3 mol / L;

[0073] (2) taking 1-(7-carboxyheptyl)-4-(pyrene-1-yl) pyridine-1-ium, dissolving in water to prepare solution B with a concentration of 1.5×10 -3 mol / L;

[0074] (3) mixing solution A and solution B, controlling the molar ratio of the spiral fourteen-membered cucurbituril and 1-(7-carboxyheptyl)-4-(pyrene-1-yl) pyridine-1-ium to be 1:2, and obtaining the supramolecular fluorescent probe by self-assembly reaction at room temperature for a few moments through standing.

[0075] Example 6

[0076] The method for detecting Hg 2+ in an aqueous solution by using the supramolecular fluorescent probe is as follows:

[0077] (1) taking the supramolecular fluorescent probe prepared in Example 1, adding water to prepare a fluorescent probe standard solution with a concentration of 2.00×10 -5 mol / L;

[0078] (2) taking the required analysis pure standard of various perchlorate cations, dissolving in a deionized water solution with pH=6.75 to obtain other metal ion standard solutions with a concentration of 1.00×10 -1 mol / L;

[0079] (3) adding the metal ion standard solution in step (2) to the fluorescent probe standard solution prepared in step (1), standing for 5 min, then determining the fluorescence emission spectrum with a fixed excitation wavelength of 385 nm, and drawing a change curve of the fluorescence intensity at an emission wavelength of 521 nm;

[0080] (4) According to the curve of step (3), the change value ΔI of the fluorescence emission spectrum intensity corresponding to 521 nm before and after adding the metal ion standard solution into the fluorescence probe standard solution is calculated, when the fluorescence emission spectrum intensity corresponding to 521 nm before and after adding the metal ion standard solution is obviously weakened, it indicates that the metal ion standard solution contains Hg 2+ , and the concentration is 0-2 times (excluding 0 and 2) of TPAPy@tQ

[14] . When the fluorescence emission spectrum intensity corresponding to 521 nm before and after adding the metal ion standard solution does not change obviously, it indicates that the metal ion standard solution does not contain Hg 2+ .

[0081] Example 7

[0082] The method for detecting Hg 2+ in an aqueous solution by using the supramolecular fluorescence probe of the application is as follows:

[0083] (1) The supramolecular fluorescence probe prepared in Example 1 is diluted with water to prepare a fluorescence probe standard solution with a concentration of 1.00×10 -5 mol / L;

[0084] (2) The required analysis pure standard of various perchlorate cations is weighed and dissolved in a deionized water solution with pH=6.75 to obtain various metal ion standard solutions with a concentration of 1.00×10 -1 mol / L;

[0085] (3) The metal ion standard solution of step (2) is added into the fluorescence probe standard solution prepared in step (1), and placed for 5 min, then the fluorescence emission spectrum is determined at a fixed excitation wavelength of 385 nm, and the change curve of the fluorescence intensity at an emission wavelength of 521 nm is drawn;

[0086] (4) According to the curve of step (3), the change value ΔI of the fluorescence emission spectrum intensity corresponding to 521 nm before and after adding the metal ion standard solution into the fluorescence probe standard solution is calculated, when the fluorescence emission spectrum intensity corresponding to 521 nm before and after adding the metal ion standard solution is obviously weakened, it indicates that the metal ion standard solution contains Hg 2+ , and the concentration is 0-2 times (excluding 0 and 2) of TPAPy@tQ

[14] . When the fluorescence emission spectrum intensity corresponding to 521 nm before and after adding the metal ion standard solution does not change obviously, it indicates that the metal ion standard solution does not contain Hg 2+ .

[0087] Example 8

[0088] The method for detecting Hg 2+ in an aqueous solution by using the supramolecular fluorescence probe of the application is as follows:

[0089] (1) The supramolecular fluorescent probe prepared in Example 1 was diluted with water to prepare a fluorescent probe standard solution with a concentration of 3.00 x 10 -5 mol / L;

[0090] (2) The required various perchloric acid cation standard samples of analytical purity were weighed and dissolved in a deionized water solution with a pH of 6.75 to obtain various metal ion standard solutions with a concentration of 1.00 x 10 -1 mol / L;

[0091] (3) The metal ion standard solution of step (2) was added to the fluorescent probe standard solution prepared in step (1), and placed for 5 min, then the fluorescence emission spectrum was determined at a fixed excitation wavelength of 385 nm, and the change curve of the fluorescence intensity at an emission wavelength of 521 nm was drawn;

[0092] (4) According to the curve of step (3), the fluorescence emission spectrum intensity change value ΔI at 521 nm before and after the addition of the metal ion standard solution to the fluorescent probe standard solution was calculated. If the fluorescence emission spectrum intensity at 521 nm before and after the addition of the metal ion standard solution is significantly weakened, it indicates that the metal ion standard solution contains Hg 2+ , and the concentration is 0-2 times (not including 0 and 2) of TPAPy@tQ

[14] . If the fluorescence emission spectrum intensity at 521 nm before and after the addition of the metal ion standard solution does not change significantly, it indicates that the metal ion standard solution does not contain Hg 2+ .

[0093] The above is only a preferred specific embodiment of the present application, but the protection scope of the present application is not limited thereto, any person skilled in the art can make equivalent replacement or change according to the technical scheme and inventive concept of the present application within the technical range disclosed by the present application, which should be covered within the protection scope of the present application.

Claims

1. A supramolecular fluorescent probe based on a cyclotetradecane cucurbituril, characterized in that, The chemical structural formula is as follows: ； wherein is a cyclotetradecaguaiacalix; The supramolecular fluorescent probe is prepared from a spiral fourteen-membered cucurbituril and 1-(7-carboxyheptyl)-4-(pyrene-1-yl)pyridine-1-ium as raw materials; the molar ratio of the spiral fourteen-membered cucurbituril and 1-(7-carboxyheptyl)-4-(pyrene-1-yl)pyridine-1-ium is 1:

2.

2. The method for preparing a supramolecular fluorescent probe based on a cavitand according to claim 1, characterized in that, Specifically, the method comprises the following steps: (1) The spiral fourteen-membered cucurbituril is taken and dissolved in water to prepare solution A; (2) 1-(7-carboxyheptyl)-4-(pyrene-1-yl)pyridine-1-ium is taken and dissolved in water to prepare solution B; (3) Solution A and solution B are mixed to obtain the supramolecular fluorescent probe through self-assembly reaction.

3. The method for preparing a supramolecular fluorescent probe based on a cavitand according to claim 2, characterized in that: The concentration of the spiral fourteen-membered cucurbituril in the solution A is 0.5 x 10 -3 -1.5 x 10 -3 mol / L.

4. The method for preparing a supramolecular fluorescent probe based on a cavitand according to claim 2, characterized in that: The concentration of 1-(7-carboxyheptyl)-4-(pyrene-1-yl)pyridinium-1-ol in the solution B is 0.5 x 10 -3 -1.5 x 10 - 3 mol / L.

5. The method for preparing a supramolecular fluorescent probe based on a cavitand according to claim 2, characterized in that: The self-assembly reaction in step (3) is carried out at room temperature.

6. Use of a supramolecular fluorescent probe based on a cavitand according to claim 1 for detecting Hg 2+ in an aqueous solution.

7. A method for detecting Hg2+ in aqueous solution by using the supramolecular fluorescent probe of claim 1. 2+ The method comprises the following steps: ​ (1) Take the supramolecular fluorescent probe, add water to prepare a fluorescent probe standard solution with a concentration of 1 x 10 -5 -3 x 10 -5 mol / L; (2) The fluorescent probe standard solution prepared in step (1) is added with the water solution to be detected, and then left to stand for 5-10 minutes, and then the fluorescence emission spectrum is determined at a fixed excitation wavelength of 385 nm, and a change curve of the fluorescence intensity excited at a corresponding excitation wavelength of 521 nm is drawn. (3) According to the change curve drawn in step (2), the fluorescence emission spectrum intensity change value ΔI at 521 nm can be compared, and the Hg2+ in water can be detected. 2+ performed.

8. The method of claim 7, wherein the supramolecular fluorescent probe detects Hg2+ in an aqueous solution. 2+ When the fluorescence emission spectrum at 521 nm is obviously weakened before and after adding the water solution to be detected, it indicates that the water solution to be detected contains Hg 2+ ; Conversely, it does not contain Hg 2+ . ​

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