A carbazolyl fluorescent molecule for rapid selective detection of multiple trace ions, and a preparation method and application thereof

Abstract

The application belongs to the field of chemical analysis and detection, and particularly relates to a preparation method of a novel carbazolyl fluorescent molecular probe for detecting multiple ions and application of the fluorescent molecular probe in detecting Al 3+ , Fe 3+ , CH3COO ‑ and F ‑ and pH of high-acidity solution. The disclosed fluorescent probe can be used for simultaneously detecting Al 3+ , Fe 3+ , F ‑ and CH3COO ‑ ions, and has good selectivity, strong anti-interference and high sensitivity; the probe also has excellent performance in detecting actual water samples. The probe can also roughly determine the pH of high-acidity solution, and has a wide application range.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of chemical analysis detection, and particularly relates to a kind of carbazolyl fluorescent molecules for fast selective detection of multiple trace ions, and its preparation method and application. BACKGROUND

[0002] Metal ions play a vital role in industry, biology, chemistry and environment, Fe 3+ is one of the essential trace elements for human body, and plays a vital role in the metabolism and transport of carbon dioxide and oxygen. Iron deficiency can cause serious diseases such as diabetes, liver and kidney damage and heart disease. The iron needed by the human body mainly comes from food and water, although a small amount of iron in water is beneficial to human health, but long-term use can also cause harm to the human body. When the content of Fe 3+ in water exceeds the standard, it will have an impact on human production and life. Al 3+ is a neurotoxin, which can cause some serious diseases such as Parkinson's and Alzheimer's disease, and also increase the risk of breast cancer. Therefore, it is very necessary to detect and control the levels of Fe 3+ and Al 3+ in different samples. F - Although it is an essential trace element for humans and animals, excessive fluoride ions can cause damage to the liver and stomach of the human body, lead to osteoporosis, and even cause death in severe cases. CH3COO - plays a vital role in the function of various enzymes and antibodies. In marine sediments, the formation and oxidation rate of acetate is often used as an indicator of organic matter decomposition. Therefore, it is also an important research direction to develop a rapid, sensitive and reliable method for detecting F - and CH3COO - . For decades, inductively coupled plasma mass spectrometry (ICP-MS), atomic absorption spectrometry (AAS), electrochemical methods, etc. have been used to detect these ions in biological and environmental samples. However, the above methods have some drawbacks, including the use of complex instruments, complex detection process, long time-consuming and non-site testing. Most importantly, these methods can only detect a single ion, not all ions simultaneously. Recently, fluorescence methods have received more attention due to their easy operation, high selectivity and sensitivity, fast response time, low cost, etc. Many fluorescent molecular probes have been developed to detect Al 3+ , Fe 3+ , F - and CH3COO -However, few probes can detect all four ions simultaneously. At present, how to continuously identify metal cations and anions is still a problem worth solving. With the increasing demand for ion detection applications, developing new fluorescent probes is a key point in the field of fluorescence detection, so it is necessary to develop a multifunctional ion detection probe.

[0003] The application discloses a preparation method of a carbazolyl fluorescent molecule 9-phenyl-6-(4-((2-(pyridin-2-yl)-2lambda 2 -diazaneylidene)methyl)phenyl)-4aH-9lambda 4 -carbazole (PCBH) and application of the fluorescent molecule, and a fluorescent molecule probe constructed by using the molecule can be used for selective detection of Al 3+ , Fe 3+ , CH3COO - , F - and H + . The probe is synthesized through two simple reactions, that is, a fluorescent parent body PCB is synthesized through a Suzuki reaction, and the final product PCBH is synthesized through Schiff base reaction of the PCB and 2-hydrazine pyridine.

[0004] The PCBH probe can be coordinated with Al 3+ and Fe 3+ , and exhibits special fluorescence properties at 475 nm. The probe is an "on" type fluorescent sensor. The fluorescence intensity of the PCBH at 475 nm has a good linear relationship with the concentration of the two ions, the probe PCBH has good selectivity and anti-interference for the two ions, and also has good performance in the detection of actual water samples. The titration product of the PCBH and Fe 3+ and Al 3+ can be used for quantitative detection of CH3COO - and F - . In addition, the probe exhibits a change that the fluorescence intensity is enhanced with the enhancement of acidity in a solution with a pH value less than 5, and can be used for acidity detection of a high-acidity solution. SUMMARY

[0005] For the above-mentioned case, one of purposes of the application is to provide a synthesis method of a fluorescent probe which is simple in synthesis, mild in reaction condition and low in cost; a second purpose is to synthesize a fluorescent molecule probe which is good in selectivity, strong in anti-interference, high in sensitivity and used for detection of Al 3+ , Fe 3+ , F - and CH3COO - ; and a third purpose is to roughly determine the pH of a high-acidity solution by using the fluorescent molecule probe.

[0006] To achieve the above object, the present application discloses the following technical solutions.

[0007] The first aspect of the present application discloses a carbazole-based fluorescent molecule for ion detection, which contains a 2-(2-benzylidene-1 2 -diazaneyl)pyridine structure.

[0008] The 2-(2-benzylidene-1 2 -diazaneyl)pyridine structure is shown as follows:

[0009]

[0010] The 2-(2-benzylidene-1 2 -diazaneyl)pyridine structure is the core recognition group of the carbazole-based fluorescent molecule.

[0011] Preferably, the specific structure of the carbazole-based fluorescent molecule is as follows:

[0012]

[0013] The second aspect of the present application discloses a method for preparing the above-mentioned carbazole-based fluorescent molecule, and the specific steps are as follows:

[0014] 1) 3-bromo-N-phenylcarbazole and benzaldehyde borate are sequentially added into a three-necked flask, and then a small amount of potassium carbonate aqueous solution is added after being dissolved in tetrahydrofuran. Under the protection of nitrogen, a tetra(triphenylphosphine)palladium catalyst is added, and heated to reflux for 13-14 h. After separation and purification, PCB is obtained, and the structural formula of the PCB is shown as follows:

[0015]

[0016] 2) The fluorescent parent PCB and 2-hydrazine pyridine are added into a high-pressure tube, and a small amount of acetic acid and anhydrous ethanol are added, and reacted at 65℃ for 12-13 h. After separation and purification, the product PCBH is obtained, and the structural formula of the PCBH is shown as follows:

[0017]

[0018] The third aspect of the present application discloses a fluorescent molecular probe, which disperses the above-mentioned PCBH into an organic-water mixed solvent to construct a fluorescent molecular probe system. The organic solvent used includes tetrahydrofuran (THF), dimethyl sulfoxide (DMSO) and dimethylformamide (DMF).

[0019] The fluorescent probe is used for specifically detecting Al 3+ , Fe 3+ and H + ions.

[0020] The fluorescent probe can also specifically detect CH3COO- and F- ions through the fluorescent product of Al 3+ , Fe 3+ ions.

[0021] The present application has the following beneficial technical effects:

[0022] The disclosed fluorescent probe can be used for simultaneously detecting Al 3+ , Fe 3+ , F - and CH3COO - ions, and has good selectivity, strong anti-interference and high sensitivity; and also performs well in the detection of actual water samples. BRIEF DESCRIPTION OF DRAWINGS

[0023] Figure 1 The fluorescence spectrum diagram of the fluorescent molecular probe after adding different cations.

[0024] Figure 2 The (a) figure in the figure is the fluorescence intensity of PCBH (1.0×10 -5 mol·L -1 ) adding Fe 3+ (1.0×10 -5 mol·L -1 ) and different metal ions (1.0×10 -5 mol·L -1 ) at 475nm; Figure 2 The (b) figure in the figure is the fluorescence intensity of PCBH (1.0×10 -5 mol·L -1 ) adding Al 3+ (1.0×10 -5 mol·L -1 ) and different metal ions (1.0×10 -5 mol·L -1 ) at 475nm.

[0025] Figure 3 a and b in the figure are respectively the fluorescence curve of the fluorescence spectrum of PCBH (1.0×10 -5 mol·L -1 ) with the change of Fe 3+ concentration from 0-60μM and the fitting curve of the fluorescence intensity at 475nm with the change of Fe 3+ concentration.Figure 3 c, d in Fig. 2 are the fluorescence spectra of PCBH (1.0 x 10 -5 mol L -1 ) with the change of Al 3+ concentration from 0-40 μM and the fitting curve of the change of fluorescence intensity with the change of Fe 3+ concentration.

[0026] Figure 4 a, b in Fig. 3 are the fluorescence spectra of the probe (1.0 x 10 -5 mol L -1 ) after complexing with Fe 3+ (1.0 x 10 -5 mol L -1 ) and then adding different anions (1.0 x 10 -5 mol L -1 ), and the pictures of the fluorescence spectra of the probe and the change of fluorescence intensity of the probe at 475 nm.

[0027] Figure 5 a, b in Fig. 4 are the fluorescence curve of the fluorescence spectra of the probe PCBH (1.0 x 10 -5 mol L -1 ) after complexing with Fe 3+ (1.0 x 10 -5 mol L -1 ) with the change of CH3COO - concentration from 0-100 μM and the fitting curve of the change of fluorescence intensity at 475 nm with the change of CH3COO -5 concentration.

[0028] Figure 6 a, b in Fig. 5 are the fluorescence spectra of the probe (1.0 x 10 -1 mol L 3+ ) after complexing with Al -5 (1.0 x 10 -1 mol L -5 ) and then adding different anions (1.0 x 10 -1 mol L -5 ), and the pictures of the fluorescence spectra of the probe and the change of fluorescence intensity of the probe at 475 nm.

[0029] Figure 7 a, b in Fig. 6 are the fluorescence curve of the fluorescence spectra of the probe PCBH (1.0 x 10 -1 mol L 3+ ) after complexing with Al -5 (1.0 x 10 -1 mol L -Fluorescence curve of the probe PCBH (1.0 x 10 - mol L -5 -1) at different concentrations and the fitted curve of fluorescence intensity at 475 nm versus F -1 - concentration from 0-200 μΜ. 3+ - 5 Fluorescence curve of the probe PCBH (1.0 x 10 -1 mol L - -1) at different concentrations and the fitted curve of fluorescence intensity at 475 nm versus F -5 - concentration from 0-100 μΜ. -1 3+ 3+ + 2+ 2+ 2+ + 3+ Figure 1 is a photograph of the test paper of the probe PCBH under 365 nm ultraviolet light after adding Fe 3+ , Al 3+ , K 3+ , Mn -5 , Pb -1 , Ni 3+ , H 3+ .DETAILED DESCRIPTION 3+ 2+ The present application is further illustrated by the following examples without limiting the present application to the examples described. The experimental methods in the following examples, if not otherwise specified, are carried out according to the conventional methods and conditions, or according to the instructions of the commercial products. The raw materials and equipment used in the examples are well known to the person skilled in the art, and are commercially available or easily obtained or prepared. 2+ + Example 1 2+ 2+ Synthesis of the fluorescent molecular probe PCBH 2+ 2+ 1. 3-bromo-N-phenylcarbazole and phenylboronic acid were added into a three-necked flask in turn, dissolved in tetrahydrofuran, and then potassium carbonate aqueous solution was added. Under nitrogen protection, palladium tetrakis (triphenylphosphine) catalyst was added, and the system was heated to 65 °C and refluxed for 13-14 h. After the reaction was completed as monitored by TLC, the product was extracted with dichloromethane and saturated brine for 3-4 times, and the organic phase was reserved. Anhydrous sodium sulfate was added to the organic phase to absorb water. Finally, the crude product was purified by column chromatography to obtain the pure product PCB. 2+ 2+ ​​​​2. The fluorescent parent compound PCB and 2-hydrazine pyridine were added sequentially to a high-pressure tube. Anhydrous ethanol was used as the solvent and acetic acid was used as the catalyst. The reaction was carried out at 65°C for 12-13 hours. The mixture was extracted 3-4 times with ethyl acetate and distilled water, and the organic phase was retained. The organic phase was treated with anhydrous sodium sulfate to absorb water, and the crude product was obtained by rotary evaporation. The crude product was purified by column chromatography to obtain PCBH.

[0037] The synthesis of this invention is shown in the figure below:

[0038]

[0039] Example 2

[0040] The fluorescence intensity of the fluorescent probe affects Al 3+ and Fe 3+ Selectivity and anti-interference experiment

[0041] To study the effect of PCBH sensor on Al 3+ and Fe 3+ The selectivity was assessed by measuring the fluorescence spectra of 17 ions before and after their addition. The concentration of the probe PCBH was 1.0 × 10⁻⁶. -5 mol·L -1 These spectroscopic analyses were performed under the same conditions, except for different types of cations, including Fe. 3+ Al 3+ Cr 3+ Cu 2+ Zn 2+ Ag + Co 2+ Cd 2+ Pb 2+ Mn 2+ Ni 2+ Hg 2+ K + Na + Mg 2+ Ba 2+ Ca 2+ ([M] n+ =1.0×10 -5 mol·L -1 From the appendix Figure 1 The fluorescence spectrum shown indicates that at 475 nm, Fe... 3+ And Al 3+ The presence of [a specific ion] significantly enhances the fluorescence intensity of the probe compared to the presence of other ions, indicating that the probe exhibits high selectivity. From the attached [a specific ion]... Figure 2 As can be seen from a and b, when Fe is added... 3+ And Al 3+When other ions are added to the probe, the fluorescence intensity of the probe is not significantly affected and remains at a high level. This indicates that the probe has good anti-interference properties and can effectively avoid interference from other ions.

[0042] Example 3

[0043] The fluorescence intensity of the probe and Fe 3+ And Al 3+ Concentration relationship experiment

[0044] Keep the probe concentration constant (1.0 × 10⁻⁶). -5 mol·L -1 The study investigated different concentrations of Fe. 3+ And Al 3+ The effect on probe fluorescence intensity, see appendix. Figure 3 a represents different concentrations of Fe. 3+ The effect on probe fluorescence intensity shows that the fluorescence intensity increases with increasing ion concentration, especially in Fe... 3+ Within the concentration range of 0-20 μM, the fluorescence intensity of the probe and Fe 3+ The concentration showed a good linear relationship. (From the attached...) Figure 3 b shows that in Al 3+ Within a concentration range of 0-15 μM, the fluorescence intensity of the probe exhibited a good linear relationship with the ion concentration. Furthermore, the fluorescence intensity of the probe gradually increased with increasing ion concentration. This indicates that the probe can effectively detect two ions over a wide linear range.

[0045] Example 4

[0046] probe and Fe 3+ After combination, CH3COO - Selective experiments

[0047] Probe PCBH (1.0×10 -5 mol·L -1 ) and Fe 3+ (1.0×10 -5 mol·L -1 After combination, CH3COO - Selective. (Attached) Figure 4 a is probe binding Fe 3+ It then reacts with different anions, including CH3COO-, F-, and S-. 2- Cl-, I-, NO3-, SCN - SO4 2- (1.0×10 -5 mol·L -1 Based on the subsequent fluorescence curves, it can be seen that only the addition of CH3COO...- The fluorescence intensity of the probe subsequently decreased significantly at 475 nm, and the addition of the other seven anions resulted in only weak fluorescence changes or no change at all. (Appendix) Figure 4 b is a bar chart showing the fluorescence intensity at 475 nm after adding different anions, further demonstrating the interaction between the probe and Fe. 3+ After combination, it exhibits excellent selectivity for CH3COO-.

[0048] Example 5

[0049] probe and Fe 3+ Combined with subsequent experiments on the linear relationship between fluorescence intensity and CH3COO- concentration

[0050] Probe PCBH (1.0×10 -5 mol·L -1 ) and Fe 3+ (1.0×10 -5 mol·L -1 After binding, different concentrations of CH3COO- were added. As the concentration of CH3COO- increased, the fluorescence intensity of the probe gradually decreased at 475 nm, as shown in the attached figure. Figure 5 As shown in a. (Attached) Figure 5 b is the probe and Fe 3+ After combining the results, the linear relationship between different concentrations of CH3COO- and fluorescence intensity can be seen. It can be seen that when the concentration of CH3COO- is 0-60μM, the ion concentration and fluorescence intensity show a good linear relationship, indicating that the probe can effectively detect CH3COO- within a relatively wide linear range.

[0051] Example 6

[0052] probe and Al 3+ After combination, CH3COO - and F - Selective experiments

[0053] Probe PCBH (1.0×10 -5 mol·L -1 ) and Al 3+ (1.0×10 -5 mol·L -1 After binding, it exhibits selectivity for CH3COO- and F-. (Appendix) Figure 6 a is probe binding Al 3+ Later, with different anions (1.0×10⁻⁶) -5 mol·L -1Combining the subsequent fluorescence curves, it can be seen that the fluorescence intensity of the probe significantly decreased at 475 nm after the addition of CH3COO- and F-, while the addition of the other six anions only resulted in weak fluorescence changes or no changes at all. (See attached image) Figure 6 b is a bar chart showing the fluorescence intensity at 475 nm after adding different anions, further demonstrating the interaction between the probe and Al. 3+ After combination, it exhibits excellent selectivity for both CH3COO- and F-.

[0054] Example 7

[0055] probe and Al 3+ Combined with subsequent experiments on the linear relationship between fluorescence intensity and CH3COO- and F- concentrations

[0056] As attached Figure 7 As shown in a and 7c, the probe PCBH (1.0×10 -5 mol·L -1 ) and Al 3+ (1.0×10 -5 mol·L -1 After combination, different concentrations of CH3COO were added. - and F - With CH3COO - With increasing F- concentration, the fluorescence intensity of the probe gradually decreases at 475 nm. (Appendix) Figure 7 b is the probe and Al 3+ After combining the results, the linear relationship between different concentrations of CH3COO- and fluorescence intensity was plotted. It can be seen that when the CH3COO- concentration is 0-110 μM, the ion concentration and fluorescence intensity exhibit a good linear relationship. (See attached image.) Figure 7 d is the probe and Al 3+ After combining the results, the linear relationship between different concentrations of F- and fluorescence intensity shows a good linear relationship between ion concentration and fluorescence intensity when the F- concentration is 0-50 μM. This indicates that the probe can effectively detect CH3COO- and F- within a relatively wide linear range.

[0057] Example 8

[0058] Experiment on the approximate pH determination of high acidity solutions using a probe

[0059] The probe PCBH exhibits unique fluorescence properties in strong acid solutions, with... Figure 8 The fluorescence intensity of the probe at 475 nm was measured in solutions with different pH values. It can be seen that the fluorescence intensity of the probe and the pH show a good linear relationship. This probe can be used to roughly determine the pH of highly acidic solutions.

[0060] While specific embodiments of the present invention have been described above in conjunction with the accompanying drawings, this is not intended to limit the scope of the invention. Various modifications or variations that can be made by those skilled in the art based on the disclosed content of the invention without creative effort are still within the protection scope of the present invention.

[0061] Example 9

[0062] The test strip method is a simple, rapid, and efficient detection method. (The text then repeats the steps of the test strip method, which is redundant and can be omitted.) -3 mol·L -1 Drop PCBH solution onto filter paper and let it air dry. During the test, drop 1×10⁻⁶ ppm of the solution onto the test paper. -3 mol·L -1 An aqueous solution of ions. (Attached) Figure 9 To add Fe 3+ Al 3+ K + Mn 2+ Pb 2+ Ni 2+ H + The image shows the PCBH test strip under 365nm ultraviolet light. It can be seen that Fe was added. 3+ Al 3+ and H + The test strip showed a significant color change upon the addition of certain ions, but no significant color change was observed after adding other ions. This indicates that the PCBH fluorescent molecular probe can be used to construct test strips for detecting Al. 3+ Fe 3+ With H + Three cations.

[0063] The above description is only 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 carbazole-based fluorescent molecule for ion detection, characterized in that, The specific structure of the carbazole-based fluorescent molecule is as follows: 。 2. The method for preparing the carbazole-based fluorescent molecule according to claim 1, characterized in that, Specifically as follows: S1: 3-Bromo-N-phenylcarbazole and benzaldehyde borate were added sequentially to a three-necked flask, dissolved in tetrahydrofuran, and a small amount of potassium carbonate aqueous solution was added. Tetra(triphenylphosphine)palladium catalyst was added under nitrogen protection, and the mixture was heated under reflux for 13-14 h. After separation and purification, PCB was obtained. The structural formula of the PCB is shown below: ； S2: Add PCB and 2-hydrazine to a high-pressure tube, add anhydrous ethanol and a small amount of acetic acid, react at 65 °C for 12-13 h, and obtain the product carbazole fluorescent molecule after separation and purification.

3. A fluorescent probe constructed from the carbazole-based fluorescent molecule of claim 1.

4. The fluorescent probe as described in claim 3, characterized in that, The fluorescent probe is used for the specific detection of Al. 3+ Fe 3+ and H + ion.

5. The fluorescent probe as described in claim 4, characterized in that, The fluorescent probe is transmitted through Al 3+ Fe 3+ The fluorescent products of the ions were further used for specific detection of CH3COO. - and F - ion.

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