Lead ion fluorescent probe and preparation and application method thereof
By adopting the fluorescence resonance energy transfer strategy in the water sample environment, and using fluorescent probes bound by pyridine groups and Eu3+, the problem of low sensitivity and insufficient specificity in the prior art is solved, and the lead ion detection effect with high selectivity and high sensitivity is achieved.
Patent Information
- Application Number
- CN202111009913.6
- Authority / Receiving Office
- CN · China
- Patent Type
- Patents(China)
- Current Assignee / Owner
- Filing Date
- 2021-08-31
- Publication Date
- 2025-04-04
- Estimated Expiration
- 2041-08-31
AI Technical Summary
The prior art is difficult to detect lead ions efficiently and accurately in a water sample environment, and there are problems such as low sensitivity and insufficient specificity.
The fluorescence resonance energy transfer strategy is adopted, and pyridine groups are used as energy donors, and three 2-thiopheneformyltrifluoroacetone (TTA) protected Eu3+ is used as energy acceptors. The energy resonance window is opened by the addition of Pb2+ to achieve high selectivity and high sensitivity detection of lead ions.
High selectivity and high sensitivity detection of lead ions is achieved in the water sample environment, and the problems of low sensitivity and insufficient specificity in the prior art have been overcome, and there is good application prospect.
Smart Images
Figure CN115724862B_ABST
Abstract
Description
Technical Field
[0001] The invention relates to the field of fluorescent probes, and in particular to a lead ion fluorescent probe and a preparation and application method thereof. Background Art
[0002] Due to the lead ion (Pb 2+ ) is highly toxic and non-degradable. It is easy to accumulate in the human body through groundwater or food chains. Once a very small amount of lead ions enter the human body, it will cause damage to the human nervous system, urinary system and immune system. Traditionally, there are many methods for detecting lead ions, including some large-scale instrument detection methods such as atomic emission spectroscopy and inductively coupled plasma mass spectrometry. Although these large-scale instrument detection methods are very accurate, they also have disadvantages such as expensive instruments, complex technology, and time-consuming analysis. There are also some rapid detection methods, such as immunoassays and electrochemical anodic stripping voltammetry, which have not been well developed due to their shortcomings in detection sensitivity and specificity.
[0003] Chemical sensors are widely used in the detection of various metal ions because of their high sensitivity, strong selectivity, simplicity and speed, and the advantages of not requiring complex and expensive instruments. An ideal chemical sensor should have the following two basic characteristics: first, the recognition group must have a good selective recognition effect with the target ion to be detected; second, on the basis of good selective recognition, the detection process should not be easily disturbed by environmental factors such as pH and temperature. Therefore, the selective recognition of the recognition group is the core of the role of the fluorescent sensor, and plays a vital role in the highly selective recognition process. However, the metal ion chemical sensors reported so far have many shortcomings in practical applications, such as being sensitive to other metal ions during detection, and most of them have unsatisfactory solubility in water, need to use organic solvents, have a narrow applicable pH range, slow reaction, low fluorescence response in water medium, and ligand discomfort, which limit their practical applications in the fields of biology and the environment. Therefore, it is essential to design and synthesize highly selective and highly sensitive metal ion chemical sensors for the detection of metal ions in water samples. Summary of the invention
[0004] The technical problem solved by the present invention is how to obtain a lead ion fluorescent probe which is suitable for detecting lead ions in a water sample environment and has high selectivity and high sensitivity.
[0005] The present invention provides a lead ion fluorescent probe, the structure of which is shown in formula (I):
[0006]
[0007] Compared with the prior art, the lead ion fluorescent probe provided by the present invention adopts the fluorescence resonance energy transfer strategy, uses the pyridine group as the energy donor, and is protected by three 2-thenoyltrifluoroacetone (TTA) groups. 3+ As an energy acceptor, Pb 2+ Previously, the energy transfer between the donor and the acceptor was blocked by the electron-rich imidazole ring. 2+ After addition, the energy resonance window opens, and the pyridine group and Eu 3+ There can be effective electron transfer between them, thus achieving the 2+ Effective detection of metal ions. + The lead ion fluorescent probe has high selectivity and high sensitivity, and can also detect Pb in environmental water samples. 2+ effective detection.
[0008] The present invention also provides a method for preparing the lead ion fluorescent probe, comprising the following steps:
[0009] S1, dissolving 2-thenoyltrifluoroacetone in ethanol, adding NaOH and europium chloride, and then adding distilled water to obtain a mixed solution 1; heating the mixed solution 1 to 60° C., reacting for half an hour, cooling, and then filtering and drying to obtain a powdery solid product (TTA) 3Eu;
[0010] S2, 1,10-phenanthroline dione is mixed with ammonium acetate, pyridine-2-carboxaldehyde and glacial acetic acid to obtain a mixed solution 2; the mixed solution 2 is stirred and refluxed for 2 hours and then cooled to room temperature to obtain a reaction solution 1; the reaction solution 1 is diluted with distilled water and then dropped into concentrated ammonia water, and a large amount of yellow precipitate is precipitated in the reaction solution 1; the precipitate is washed with water several times to obtain a crude product, and the crude product is recrystallized in ethanol several times to obtain 2-(2-pyridyl)-1H-imidazole [4,5-f][1,10] phenanthroline (PPh);
[0011] S3. Mix the (TTA)3Eu obtained in step S1 and the PPh obtained in step S2 in ethanol, reflux and stir for 5 hours, and then cool to room temperature to obtain reaction solution 2; transfer the reaction solution 2 into a test tube, and place the test tube in a wide-mouth bottle containing anhydrous ether, and let it stand for one week to obtain a lead ion fluorescent probe.
[0012] The reaction formula for the preparation of the lead ion fluorescent probe is as follows:
[0013]
[0014] The lead ion fluorescent probe preparation method comprises the following steps: synthesizing the lead ion fluorescent probe by alcohol-thermal reaction of 2-thenoyltrifluoroacetone, 2-(2-pyridyl)-1H-imidazole[4,5-f][1,10]phenanthroline (PPh) and europium chloride; the synthesis method is simple, the operation is simple, and harsh conditions are not required.
[0015] Preferably, in step S1, the molar ratio of the 2-thenoyltrifluoroacetone to the europium chloride is 3: 1. Controlling the molar ratio of the 2-thenoyltrifluoroacetone to the europium chloride to be 3: 1 is beneficial for synthesizing (TTA)3Eu.
[0016] Preferably, in step S2, the molar ratio of 1,10-phenanthroline dione to the ammonium acetate, the pyridine-2-carboxaldehyde and the glacial acetic acid is 1:40:2:30. Controlling the molar ratio of 1,10-phenanthroline dione, ammonium acetate, pyridine-2-carboxaldehyde and glacial acetic acid is beneficial to the synthesis of PPh.
[0017] Preferably, the molar ratio of (TTA)3Eu to PPh in step S3 is 1: 1. Controlling the molar ratio of (TTA)3Eu to PPh is beneficial for synthesizing the lead ion fluorescent probe.
[0018] The present invention also provides the lead ion fluorescent probe in Pb 2+ Applications in ion detection.
[0019] The lead ion fluorescent probe is 2+ Application in ion detection, the application method is:
[0020] Step 1: Prepare different concentrations of Pb 2+ ion aqueous solution, adding the fluorescent probe compound into the aqueous solution to obtain a fluorescent probe reaction solution; adding the fluorescent probe reaction solution into a fluorescent cuvette, and then adding the same volume and different concentrations of Pb 2+ Ion aqueous solution, fluorescence intensity detection, Pb 2+ Concentration and fluorescence intensity relationship curve;
[0021] Step 2: Take the environmental water sample to be tested and filter out the insoluble matter; take the same volume of the fluorescent probe reaction solution as in step 1, add the same volume of the environmental water sample to be tested as in step 1, and perform fluorescence intensity detection. According to the sample fluorescence intensity obtained by the detection, compare the Pb obtained in step 1 with the fluorescence intensity of the sample. 2+ The relationship between ion concentration and fluorescence intensity curve can be used to obtain the Pb content in the sample to be tested. 2+ concentration.
[0022] The lead ion fluorescent probe is applied to Pb 2+It has the advantages of convenience, high sensitivity, and strong specificity in Pb ion detection, overcoming the shortcomings of conventional detection methods such as poor sensitivity, large interference, complex pretreatment, and expensive instruments. It is a simple and practical Pb 2+ Ion qualitative and quantitative analysis technology.
[0023] The lead ion fluorescent probe coordination compound disclosed in the present invention has the following beneficial effects: the lead ion fluorescent probe provided by the present invention has the advantages of stable performance, simple preparation process, high fluorescence efficiency and long duration. The fluorescent probe has high selectivity and high sensitivity to lead ions, and can achieve Pb in environmental water samples. 2+ Identification and detection of ions, and other metal ions or trace elements have no significant effect on the test results. 2+ It has good application prospects in ion detection. BRIEF DESCRIPTION OF THE DRAWINGS
[0024] Figure 1 This is a schematic diagram of the lead ion fluorescent probe detection mechanism;
[0025] Figure 2 is a fluorescence intensity diagram of different metal ions in Example 3;
[0026] Figure 3 The different concentrations of lead nitrate 2*10 -7 mmol / L, 4*10 - 7 mmol / L, 6*10 -7 mmol / L、8*10 -7 mmol / L, 1*10 -6 Fluorescence spectrum of mmol / L solution;
[0027] Figure 4 is the concentration of lead nitrate and I in Example 3 617 nm / I 417 The fluorescence intensity is linearly related to nm. DETAILED DESCRIPTION
[0028] The technical solution of the present invention will be clearly and completely described below in conjunction with the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.
[0029] The present invention discloses a lead ion fluorescent probe, the structure of which is shown in formula (I):
[0030]
[0031] Compared with the prior art, the lead ion fluorescent probe provided by the present invention has the following detection mechanism: Figure 1 As shown in the figure, the fluorescence resonance energy transfer strategy was used to utilize the pyridine group as an energy donor. Eu2O3 protected by three 2-thenoyltrifluoroacetone (TTA) 3+ As an energy acceptor, Pb 2+ Previously, the energy transfer between the donor and the acceptor was blocked by the electron-rich imidazole ring. 2+ After the addition, the energy resonance window opens, and the pyridine group and Eu 3+ There can be effective electron transfer between them, thus achieving the 2+ Effective detection of metal ions. + The lead ion fluorescent probe has high selectivity and high sensitivity, and can also detect Pb in environmental water samples. 2+ It can effectively detect the content of ions without being affected by other metal ions or trace elements.
[0032] Example 1
[0033] Step 1: Dissolve 1.33 g (6 mmol) of TTA in 20 mL of ethanol, add 6 mL of NaOH (1 mol / L) and 2 mmol of europium chloride, and then add 200 mL of distilled water. Heat to 60°C, react for half an hour, then cool, filter and dry to obtain a light yellow powdery solid product (TTA) 3Eu.
[0034] Step 2: Mix 1mmol 1-10-phenanthroline dione, 40mmol ammonium acetate, 2mmol formaldehyde 2-pyridine and 30mol glacial acetic acid, reflux for 2h and then cool to room temperature. After dilution, add concentrated ammonia water dropwise to precipitate a large amount of yellow precipitate. Wash with water several times and recrystallize in ethanol several times to obtain a light yellow powder solid PPh;
[0035] Step 3: Mix 0.1 mmol PPh and 0.1 mmol (TTA) 3 Eu in 20 mL ethanol, reflux and stir for 5 h, then cool to room temperature. Transfer the reaction solution to a test tube and place it in a wide-mouth bottle containing about 100 mL of anhydrous ether. After standing for one week, a yellow powder solid is obtained. Collect and dry to obtain the fluorescent probe (TTA) 3 EuPPh.
[0036] Example 2
[0037] The lead ion fluorescent probe prepared in Example 1 was applied to Pb 2+ During the test, the application method is:
[0038] Step 1: Prepare different concentrations of Pb 2+ion aqueous solution, adding the fluorescent probe compound to the aqueous solution to obtain a fluorescent probe reaction solution; adding the fluorescent probe reaction solution to a fluorescent cuvette, and then adding the same volume and different concentrations of Pb 2+ Ion aqueous solution, using 350nm excitation wavelength for fluorescence intensity detection, Pb 2+ Concentration and fluorescence intensity relationship curve;
[0039] Step 2: Take the environmental water sample to be tested and filter out the insoluble matter; take the same volume of fluorescent probe reaction solution as in step 1, add the same volume of environmental water sample to be tested as in step 1, use 350nm excitation wavelength to detect the fluorescence intensity, and compare the fluorescence intensity of the sample obtained in step 1 with the Pb 2+ The relationship between ion concentration and fluorescence intensity curve can be used to obtain the Pb content in the sample to be tested. 2+ concentration.
[0040] Example 3
[0041] The method of Example 2 was used to treat Pb 2+ During the test, alkali metals, alkaline earth metals, first transition elements and heavy metals are added to the test environmental water sample solution in step 2 at the same time, and the concentration of metal ions is 1*10 -5 mmol / L, the fluorescence intensity of each metal ion measured is as follows Figure 2 As shown. Figure 2 It can be seen that when Pb is added at the same time 2+ Compared with other metal ions, it was found that other metal ions did not interfere with the probe's detection of Pb 2+ selectivity.
[0042] And the placement experiment proved that the fluorescence intensity of the probe was not affected after being placed for 12h, 24h, and 48h.
[0043] The method of Example 2 was used to treat Pb 2+ During the detection, different concentrations of Pb 2+ The fluorescence spectrum of ions is Figure 3 As shown. Figure 3 It can be seen that the fluorescence spectrum has two strong peaks at 417 nm and 617 nm, respectively, indicating that the emission wavelengths of the lead ion fluorescent probe under an excitation wavelength of 350 nm are 417 nm and 617 nm.
[0044] Figure 4 is the concentration of lead nitrate and I 617 nm / I 417 nm fluorescence intensity linear relationship, it can be seen that as Pb 2+ During the addition process, the fluorescence intensities at 417nm and 617nm are constantly changing.-7 mmol / L~8*10 - 7 mmol / L has a linear relationship. Its R2=0.99927 has a good linear relationship. This phenomenon shows that under this condition, the lead ion fluorescent probe can be used as a chemistries to measure Pb 2+ Quantitative detection of .
[0045] Although the disclosure is disclosed as above, the protection scope of the disclosure is not limited thereto. Those skilled in the art can make various changes and modifications without departing from the spirit and scope of the disclosure, and these changes and modifications will fall within the protection scope of the present invention.
Claims
1. A lead ion fluorescent probe, characterized in that: The structure of the fluorescent probe is as follows: The method for preparing the fluorescent probe comprises the following steps: S1. Dissolve 2-thenoyltrifluoroacetone (TTA) in ethanol, add NaOH and europium chloride, and then add distilled water to obtain a mixed solution 1; heat the mixed solution 1 to 60°C, react for half an hour, cool, and then filter and dry to obtain a powdered solid product (TTA) 3Eu; S2, mixing 1,10-phenanthroline dione with ammonium acetate, pyridine-2-carboxaldehyde and glacial acetic acid to obtain a mixed solution II; stirring the mixed solution II under reflux for 2 h and then cooling it to room temperature to obtain a reaction solution I; diluting the reaction solution I with distilled water and then dropping concentrated ammonia water into it, a large amount of yellow precipitate is precipitated in the reaction solution I; washing the precipitate with water several times to obtain a crude product, and then recrystallizing the crude product in ethanol several times to obtain 2-(2-pyridyl)-1H-imidazole [4,5-f] [1,10] phenanthroline; S3. Mix the (TTA)3Eu obtained in step S1 and the 2-(2-pyridyl)-1H-imidazole [4,5-f] [1,10]-1,10-phenanthroline obtained in step S2 in ethanol, reflux and stir for 5 hours, and then cool to room temperature to obtain reaction solution 2; transfer the reaction solution 2 into a test tube, and place the test tube in a wide-mouth bottle containing anhydrous ether, and let it stand for one week to obtain a lead ion fluorescent probe.
2. The fluorescent probe according to claim 1, characterized in that The molar ratio of the 2-thenoyltrifluoroacetone (TTA) to the europium chloride in step S1 is 3:
1.
3. The fluorescent probe according to claim 1, characterized in that In step S2, the molar ratio of 1,10-phenanthrolinedione to the ammonium acetate, the pyridine-2-carboxaldehyde and the glacial acetic acid is 1:40:2:
30.
4. The fluorescent probe according to claim 1, characterized in that In step S3, the molar ratio of (TTA)3Eu to the 2-(2-pyridyl)-1H-imidazole[4,5-f][1,10]phenanthroline is 1:
1.
5. An application of a fluorescent probe, characterized in that: The fluorescent probe described in claim 1 is applied to Pb in environmental water samples 2+ Ion detection.
6. The use of the fluorescent probe according to claim 5, characterized in that: The application method is: Step 1: Prepare different concentrations of Pb 2+ ion aqueous solution, adding the fluorescent probe into the aqueous solution to obtain a fluorescent probe reaction solution; adding the fluorescent probe reaction solution into a fluorescent cuvette, and then adding the same volume and different concentrations of Pb 2+ Ion aqueous solution, fluorescence intensity detection, Pb 2+ Concentration and fluorescence intensity relationship curve; Step 2: Take the environmental water sample to be tested and filter out the insoluble matter; take the same volume of the fluorescent probe reaction solution as in step 1, add the same volume of the environmental water sample to be tested as in step 1, and perform fluorescence intensity detection. According to the sample fluorescence intensity obtained by the detection, compare the Pb obtained in step 1 with the fluorescence intensity of the sample. 2+ The relationship between ion concentration and fluorescence intensity curve can be used to obtain the Pb content in the sample to be tested. 2+ concentration.