A thiazole hydroxy benzene dithio propionic acid zirconium ion fluorescent probe and a preparation method thereof

Abstract

This invention relates to a thiazole hydroxyphenyl dithiopropionic acid-based zirconium ion fluorescent probe and its preparation method. The preparation method involves a condensation reaction between ethyl 2-(3-aldehyde-4-hydroxyphenyl)-4-methylthiazole-5-carboxylate and mercaptopropionic acid to obtain a thiazole hydroxyphenyl dithiopropionic acid-based Zr ion fluorescent probe. 4+ Fluorescent probe. This invention provides a simple preparation and detection method for a thiazole hydroxyphenyl dithiopropionic acid-based fluorescent probe. It exhibits strong specificity, a wide pH range, and produces blue fluorescence upon binding with zirconium ions, allowing direct detection under ultraviolet light. This method can be applied to natural environments and areas contaminated with transition metals such as mines and chemical plants. 4+ Its convenient and efficient detection capabilities have significant practical application and expansion value.

Description

Technical Field

[0001] This invention relates to a thiazole hydroxybenzene dithiopropionic acid zirconium ion fluorescent probe and its preparation method, specifically belonging to the field of organic functional materials. Background Technology

[0002] Zirconium is a high-melting-point, silvery-gray rare transition metal, primarily existing in the Earth's crust as minerals such as zircon (ZrSiO4) and zircon (ZrO2). It is found only in trace amounts in natural water bodies and soil, with almost no accumulation in organisms and slow metabolic excretion. Due to its corrosion resistance, high neutron transparency, and chemical stability, zirconium and its compounds have wide applications in the nuclear industry, ceramic materials, chemical catalysis, and leather tanning. However, zirconium ions are high-charge-density oxyphilic metal ions, easily combining and accumulating with particulate matter in the environment. Excessive zirconium ions can be toxic to aquatic organisms and soil microorganisms, and long-term exposure can irritate the human respiratory tract and skin, posing significant potential ecological and health risks. Therefore, the development of zirconium-containing minerals is crucial. 4+ Developing efficient and convenient identification methods to achieve specificity, high sensitivity, and trace detection is of paramount importance.

[0003] Zr 4+ Traditional detection methods for Zr mainly include inductively coupled plasma mass spectrometry (ICP-MS) and atomic absorption spectrometry (AAS). These methods typically require large, precision instruments, involve complex sample pretreatment, are time-consuming, and are difficult to implement in real-time on-site monitoring. In recent years, fluorescence and colorimetric detection techniques have become effective methods for ion detection due to their advantages of speed, sensitivity, ease of operation, and visual monitoring. Currently, compared to other metal ions, Zr has been developed... 4+ Fluorescent probes are relatively scarce. The applicant of this invention has proposed a hydroxyquinoline disulfide zirconium ion fluorescent probe and its preparation method. The probe structure is hydroxyquinoline-dithiocarbamate, exhibiting a colorless to green fluorescence enhancement response before and after zirconium ion recognition and strong anti-interference ability. However, this probe suffers from drawbacks such as the multi-step synthesis route making large-scale production difficult. While the benzimidazole-triazole zirconium ion probe synthesized by Gurjaspreet et al. has high sensitivity and both antioxidant and anticancer activities, it only exhibits a colorimetric response without fluorescence signal change, and its binding affinity is weak, failing to meet imaging requirements. Fluorescent probes constructed using thiazole-hydroxybenzene dithiopropionic acid recognition units exhibit good coordination selectivity and solubility, and can provide multiple coordination sites for specific recognition of Zr. 4+ It exhibits enhanced green to blue fluorescence response before and after zirconium ion recognition, and is unaffected by interference from common metal ions, enabling rapid identification and on-site detection. Therefore, the design and development of a system capable of detecting Zr... 4+Developing convenient, sensitive, and highly selective fluorescent probes is of great research significance and practical application value. Summary of the Invention

[0004] In view of the above situation, the present invention provides a thiazole hydroxybenzene dithiopropionic acid zirconium ion fluorescent probe and its preparation method, which realizes the specific identification and detection of zirconium ions and has the characteristics of simple preparation, good selectivity, high sensitivity, strong anti-interference ability and wide pH range.

[0005] The chemical structural formula of the thiazole hydroxybenzene dithiopropionic acid-based zirconium ion fluorescent probe of this invention is as follows: ; A method for preparing a zirconium ion fluorescent probe of thiazole hydroxyphenyl dithiopropionic acid is to use ethyl 2-(3-aldehyde-4-hydroxyphenyl)-4-methylthiazole-5-carboxylic acid and mercaptopropionic acid as raw materials, and boron trifluoride diethyl ether as catalyst, to obtain the zirconium ion fluorescent probe of thiazole hydroxyphenyl dithiopropionic acid through a condensation reaction. The specific process is as follows: Under argon protection, ethyl 2-(3-aldehyde-4-hydroxyphenyl)-4-methylthiazole-5-carboxylic acid, mercaptopropionic acid, and boron trifluoride diethyl ether were placed in dichloromethane solvent and condensed at 0°C for 6 h. The reaction progress was monitored by thin-layer chromatography. After the reaction was completed, a white precipitate was precipitated in the reaction solution. The precipitate was then filtered under reduced pressure and washed with anhydrous ethanol to obtain a zirconium ion fluorescent probe of thiazole hydroxyphenyl dithiopropionic acid.

[0006] The molar ratio of 2-(3-aldehyde-4-hydroxyphenyl)-4-methylthiazol-5-carboxylic acid ethyl ester, mercaptopropionic acid and boron trifluoride diethyl ether is 1:2.1:0.2.

[0007] The reaction equation for this invention is as follows: ; Wherein: SH represents a zirconium ion fluorescent probe of thiazole hydroxybenzene dithiopropionic acid type.

[0008] This invention uses ethyl 2-(3-aldehyde-4-hydroxyphenyl)-4-methylthiazolium-5-carboxylic acid and mercaptopropionic acid as raw materials, and boron trifluoride diethyl ether as a catalyst, to prepare 3,3′-{[5-(5-ethoxycarbonyl-4-methylthiazol-2-yl)-2-hydroxyphenyl]methylenebis(thioalkyl)}dipropionic acid (SH) via a condensation reaction, which is a zirconium ion fluorescent probe of thiazolium hydroxyphenyl dithiopropionic acid.

[0009] Method of using the thiazole hydroxybenzene dithiopropionic acid zirconium ion fluorescent probe of this invention: zirconium ions Zr 4+An aqueous solution of Zr was added dropwise to a mixed solution of dimethylformamide (DMF) / H₂O (8:2, v / v, 30 μL) containing the zirconium ion fluorescent probe SH. During the process, the solution was observed to change from green fluorescence to blue fluorescence. 4+ Other metal cations, besides those that are not present, show no fluorescence change.

[0010] The specific steps are as follows: Add appropriate amounts of DMF / H2O (8:2, v / v) solvent to 19 5 mL centrifuge tubes, and then add drops of Li to each centrifuge tube. + Na + Mg 2+ Al 3+ , K + Ca 2+ , Cr 3+ , Mn 2+ Fe 2+ Fe 3+ Co 2+ Ni 2+ Zn 2+ Ag + Cd 2+ Ba 2+ Hg 2+ Pb 2+ and Zr 4+ An aqueous solution was prepared, and finally 30 μL of a 1 mmol / L DMF / H2O (8:2, v / v) solution of the fluorescent probe SH was added. Zr was observed to be present in the solution under UV light. 4+ The aqueous solution in the centrifuge tube changed from green fluorescence to blue, while other metal cation solutions showed no fluorescence change.

[0011] The beneficial effects of this invention are: 1. This invention employs a one-step condensation reaction, which is simple to prepare, has mild reaction conditions, uses inexpensive raw materials, and yields high output. 2. The present invention relates to thiazole hydroxybenzene dithiopropionic acid Zr 4+ The fluorescent probe features a novel molecular structure, excellent solubility, strong anti-interference ability, wide pH range, specific recognition, high selectivity, and high sensitivity, effectively distinguishing metallic Zr. 4+ And other common metal ions; 3. The thiazole hydroxybenzene dithiopropionic acid-based zirconium ion fluorescent probe of this invention has a wide range of applications, exhibits good detection performance over a wide pH range, has a short response time, and does not generate secondary pollution during use, which is beneficial to the protection of Zr in water bodies and the environment. 4+ Trace analysis and detection of this material has significant application prospects and promotional value. Attached Figure Description

[0012] Figure 1 The chemical structural formula of the thiazole hydroxybenzene dithiopropionic acid zirconium ion fluorescent probe of this invention;

[0013] Figure 2 The proton nuclear magnetic resonance spectrum of the thiazole hydroxybenzene dithiopropionic acid zirconium ion fluorescent probe of this invention ( 1 H-NMR spectrum;

[0014] Figure 3 The present invention relates to a thiazole hydroxyphenyl dithiopropionic acid-based zirconium ion fluorescent probe for the detection of Zr in a DMF / H2O system. 4+ Fluorescence changes in response;

[0015] Figure 4 The present invention relates to a thiazole hydroxyphenyl dithiopropionic acid-based zirconium ion fluorescent probe for different concentrations of Zr in a DMF / H2O system. 4+ Fluorescence emission spectrum;

[0016] Figure 5 The fluorescence enhancement of the thiazole hydroxyphenyl dithiopropionic acid-based zirconium ion fluorescent probe of this invention in the DMF / H2O system is related to that of Zr. 4+ The relationship between concentrations;

[0017] Figure 6 The present invention relates to a thiazole hydroxyphenyl dithiopropionic acid-based zirconium ion fluorescent probe in a DMF / H2O system, wherein the probe molecules SH and Zr... 4+ Combined Job curves;

[0018] Figure 7 This invention relates to the test of the anti-interference ability of the thiazole hydroxybenzene dithiopropionic acid zirconium ion fluorescent probe in the presence of different metal ions.

[0019] Figure 8 The fluorescence intensity variation of the thiazole hydroxybenzene dithiopropionic acid zirconium ion fluorescent probe of this invention under different pH conditions;

[0020] Figure 9 The present invention discloses the relationship between fluorescence intensity and response time of a thiazole hydroxybenzene dithiopropionic acid-based zirconium ion fluorescent probe. Detailed Implementation

[0021] The present invention will now be described in detail with reference to the accompanying drawings, but it should be noted that the implementation of the present invention is not limited to the following embodiments.

[0022] Example 1 Synthesis of thiazole hydroxybenzene dithiopropionic acid zirconium ion fluorescent probes Under argon protection, ethyl 2-(3-aldehyde-4-hydroxyphenyl)-4-methylthiazolium-5-carboxylate (0.5826 g, 2 mmol) and mercaptopropionic acid (368 μL, 4.2 mmol) were placed in 15 mL of dichloromethane solvent, and boron trifluoride diethyl ether (50 μL, 0.4 mmol) was added. The reaction was carried out at 0 °C for 6 h. The reaction progress was monitored by thin-layer chromatography (TLC). After the starting material sites reacted completely, the reaction was stopped. A white precipitate precipitated in the reaction solution. After vacuum filtration and washing with anhydrous ethanol, the zirconium ion fluorescent probe SH (0.8578 g, yield 88.3%) of thiazolium hydroxyphenyl dithiopropionic acid was obtained.

[0023] The 1H NMR spectrum of a thiazole hydroxybenzene dithiopropionic acid zirconium ion fluorescent probe is as follows: Figure 2 As shown. 1 H NMR (500 MHz, DMSO-) d 6) δ 10.75 (s, 1H), 8.07 (d, J = 2.3 Hz, 1H), 7.75 (dd, J =8.4, 2.4 Hz, 1H), 6.96 (d, J = 8.4 Hz, 1H), 5.47 (s, 1H), 4.29 (q, J = 7.1Hz, 2H), 2.78 (dt, J = 14.0, 7.1 Hz, 2H), 2.70 (s, 1H), 2.67 - 2.62 (m, 2H), 2.53 (d, J = 7.1 Hz, 6H), 1.31 (t, J = 7.1 Hz, 3H).

[0024] The spectra clearly show that the thiazole hydroxybenzene dithiopropionic acid zirconium ion fluorescent probe molecule SH prepared in this invention has the same structure as the target molecule.

[0025] Example 2 Thiazole hydroxybenzene dithiopropionic acid zirconium ion fluorescent probe for Zr 4+ Selective detection of fluorescence response The DMF / H2O (8∶2, v / v) system was used as the experimental testing environment.

[0026] The fluorescent probe SH was dissolved in DMF solvent and diluted to a volumetric flask of 50 mL to prepare a solution with a concentration of 1 mmol / L, which is the ion detection solution.

[0027] Take 20 centrifuge tubes (5 mL each), and add 2.37 mL of DMF solvent to each tube. The first centrifuge tube serves as the blank control group. Add 0.15 mL of 1 mmol / L Li-containing solvent to the remaining 19 centrifuge tubes. + Na + Mg 2+ Al 3+ , K + Ca 2+ , Cr 3+ , Mn 2+ Fe 2+ Fe 3+ Co 2+ Ni 2+ Zn 2+ Ag + Cd 2+ Ba 2+ Hg 2+ Pb 2+ and Zr 4+ The sample solution was prepared by adding 0.45 mL of aqueous solution and deionized water, followed by 0.03 mL of 1 mmol / L ion detection solution. After allowing the sample solutions in each centrifuge tube to stand for 1 min, they were transferred to standard quartz cuvettes, and the fluorescence spectrum changes were measured. The maximum emission wavelength was 471 nm.

[0028] The fluorescence response of the fluorescent probe SH to different metal ions is as follows: Figure 3 As shown. The results indicate that the fluorescent probe SH reacts with Zr. 4+ After binding, the fluorescence emission peak shifts to 471 nm, changing from green to blue fluorescence. Experimental results show that the fluorescent probe SH of this invention is effective for Zr. 4+ It has a highly sensitive and specific fluorescence enhancement effect.

[0029] Example 3 Thiazole hydroxybenzene dithiopropionic acid Zr 4+ Fluorescent probes for Zr 4+ Quantitative fluorescence detection The DMF / H2O (8∶2, v / v) system was used as the experimental testing environment.

[0030] Take 17 centrifuge tubes (5 mL each), add 2.37 mL of DMF solvent and 0.552–0.6 mL of deionized water to each tube, and then add 0 μM–16 μM Zr at a concentration of 1 mmol / L to each tube. 4+Add 0.03 mL of 1 mmol / L ion detection solution to each centrifuge tube, followed by 0.048 mL of aqueous solution. Let the samples stand for 1 min, then transfer them to a standard quartz cuvette and measure the changes in their fluorescence spectra.

[0031] Thiazole hydroxybenzene dithiopropionic acid Zr 4+ Fluorescent probes for different concentrations of Zr 4+ The fluorescence emission spectrum is as follows Figure 4 As shown. The fluorescence intensity value at 471 nm in the fluorescence emission spectrum is compared with the corresponding Zr. 4+ A standard curve is obtained by fitting the concentration equivalent ratio (e.g.) Figure 5 As shown in the figure, the results show a good linear relationship, indicating that the thiazole hydroxybenzene dithiopropionic acid Zr involved in this invention 4+ Fluorescent probes can be used to quantitatively detect Zr in a DMF / H2O system. 4+ concentration.

[0032] Example 4 probe molecules SH and Zr in solution system 4+ Complexation ratio The DMF / H2O (8∶2, v / v) system was used as the experimental testing environment.

[0033] Take nine 5 mL centrifuge tubes and control probes SH and Zr. 4+ The sum of the concentrations was 50 μM. Probe molecule SH solution / Zr was added to each centrifuge tube. 4+ Solutions with molar concentration ratios of 1:9, 2:8, 3:7, 4:6, 5:5, 6:4, 7:3, 8:2, and 9:1 were prepared, and DMF solvent (2.265-2.385 mL) and deionized water (0.465-0.585 mL) were added respectively, maintaining a total volume of 3 mL. The samples were allowed to stand for 30 min, then transferred to a standard quartz cuvette, and their fluorescence value at 471 nm was measured.

[0034] Thiazole hydroxybenzene dithiopropionic acid Zr 4+ Fluorescent probes in DMF / H2O system: probe molecules SH and Zr 4+ Combined Job curves, such as Figure 6 As shown. The result displays [SH] / ([SH]+[Zr]). 4+ The inflection point occurs when the value is 0.5, indicating that the thiazole hydroxybenzene dithiopropionic acid Zr involved in this invention... 4+ Fluorescent probes in DMF / H2O system: probe molecules SH and Zr 4+ The complexation ratio is 1:1.

[0035] Example 5 Thiazole hydroxybenzene dithiopropionic acid Zr 4+ Anti-interference capability test of fluorescent probe The DMF / H2O (8∶2, v / v) system was used as the experimental testing environment.

[0036] Forty 5 mL centrifuge tubes were divided into two groups of 20 each. In the first group, each tube contained 2.37 mL of DMF solvent and 0.45 mL of deionized water. The first tube served as a blank control. The remaining 19 tubes contained 0.15 mL of a 1 mmol / L solution containing Li. + Na + Mg 2+ Al 3+ , K + Ca 2+ , Cr 3+ , Mn 2+ Fe 2 + Fe 3+ Co 2+ Ni 2+ Zn 2+ Ag + Cd 2+ Ba 2+ Hg 2+ Pb 2+ and Zr 4+ The aqueous solution was first added, followed by 0.03 mL of ion detection solution. In the second group, each sample tube was added with 2.37 mL of DMF solvent and 0.15 mL of 1 mmol / L Zr. 4+ Aqueous solution: 0.3 mL of deionized water was used. The first sample tube served as a blank control group, and the remaining 19 centrifuge tubes were each supplemented with 0.15 mL of a 1 mmol / L solution containing Li. + Na + Mg 2+ Al 3+ , K + Ca 2+ , Cr 3+ , Mn 2+ Fe 2+ Fe 3+ Co 2+ Ni 2+ Zn 2+ Ag + Cd 2+ Ba 2+ Hg 2+ Pb 2+and Zr 4+ The aqueous solution was then added, followed by 0.03 mL of 1 mmol / L ion detection solution. After standing for 1 min, the sample solution was transferred to a standard quartz cuvette, and its fluorescence intensity at 471 nm was measured.

[0037] Thiazole hydroxybenzene dithiopropionic acid Zr 4+ The anti-interference ability of fluorescent probes, such as Figure 7 As shown. The results show that, except for Fe 2+ Aside from slight interference in the aqueous solution, other conditions were normal without the addition of Zr. 4+ The fluorescence value in the solution is weak; wait until Zr is added to the solution. 4+ Subsequently, the fluorescence was significantly enhanced. This result indicates that the thiazole hydroxybenzene dithiopropionic acid Zr prepared in this invention... 4+ Fluorescent probes have strong resistance to interference in the presence of most metal ions.

[0038] Example 6 pH of thiazole hydroxyphenyl dithiopropionic acid Zr 4+ Impact of fluorescent probe recognition performance The DMF / H2O (8∶2, v / v) system was used as the experimental testing environment.

[0039] Eleven groups of aqueous solutions with different pH values ​​ranging from 2 to 12 were prepared as pH adjusters.

[0040] Take 22 centrifuge tubes (5 mL each) and divide them into two groups of 11 tubes each. In the first group, add 2.37 mL of DMF solvent, 0.45 mL of pH adjuster (pH 2-12), and 0.15 mL of 1 mmol / L Zr to each sample tube. 4+ For the first group, add 0.03 mL of an aqueous solution and 0.03 mL of a 1 mmol / L ion detection solution. For the second group, add 2.37 mL of DMF solvent, 0.6 mL of pH adjuster (pH 2-12), and 0.03 mL of a 1 mmol / L ion detection solution to each sample tube. Let the sample solutions stand for 1 min, then transfer them to a standard quartz cuvette and measure their fluorescence value at 471 nm.

[0041] Thiazole hydroxybenzene dithiopropionic acid Zr 4+ The fluorescence intensity changes of the fluorescent probe under different pH conditions are as follows: Figure 8 As shown in the figure. The results show that the SH probe itself exhibits weak fluorescence changes in the pH range of 2-12, and the SH probe and Zr... 4+ After binding, it exhibits strong fluorescence changes within the pH range of 4-11. The results indicate that the thiazole hydroxybenzene dithiopropionic acid Zr prepared in this invention... 4+The fluorescent probe is suitable for Zr under a wide range of pH conditions. 4+ Testing.

[0042] Example 7 Thiazole hydroxybenzene dithiopropionic acid Zr 4+ Response time determination of fluorescent probes The DMF / H2O (8∶2, v / v) system was used as the experimental testing environment.

[0043] Take a 5 mL centrifuge tube and add 2.37 mL of DMF solvent, 0.45 mL of deionized water, and 0.15 mL of 1 mmol / L Zr. 4+ Aqueous solution. Transfer the solution from the sample tube to a standard quartz cuvette, add 0.03 mL of 1 mmol / L ion detection solution, and immediately place the cuvette in a fluorescence spectrometer for detection. Measure the fluorescence value and obtain a time-fluorescence value change spectrum.

[0044] Thiazole hydroxybenzene dithiopropionic acid Zr 4+ The fluorescence intensity of the fluorescent probe at different times, such as Figure 9 As shown in the figure. The results show that the fluorescence intensity of the fluorescent probe SH prepared in this invention increases with time, reaches a peak at 750 seconds, and remains stable.

Claims

1. A thiazole hydroxyphenyl dithiopropionic acid-based zirconium ion fluorescent probe, characterized by: The chemical structural formula of the thiazole hydroxybenzene dithiopropionic acid zirconium ion fluorescent probe is as follows: 。 2. A method for preparing a thiazole hydroxybenzene dithiopropionic acid-based zirconium ion fluorescent probe, characterized in that: The preparation method described above uses ethyl 2-(3-aldehyde-4-hydroxyphenyl)-4-methylthiazolium-5-carboxylate and mercaptopropionic acid as raw materials, and boron trifluoride diethyl ether as catalyst to prepare zirconium ion fluorescent probes of thiazolium hydroxyphenyl dithiopropionic acid through condensation reaction. The specific process is as follows: Under argon protection, ethyl 2-(3-aldehyde-4-hydroxyphenyl)-4-methylthiazole-5-carboxylic acid, mercaptopropionic acid, and boron trifluoride diethyl ether were placed in dichloromethane solvent and condensed at 0°C for 6 h. The reaction progress was monitored by thin-layer chromatography. After the reaction was completed, a white precipitate was precipitated in the reaction solution. The precipitate was then filtered under reduced pressure and washed with anhydrous ethanol to obtain a zirconium ion fluorescent probe of thiazole hydroxyphenyl dithiopropionic acid.

3. The preparation method of a thiazole hydroxy benzene dithio propionic acid zirconium ion fluorescent probe according to claim 2, characterized in that: The molar ratio of 2-(3-aldehyde-4-hydroxyphenyl)-4-methylthiazol-5-carboxylic acid ethyl ester, mercaptopropionic acid and boron trifluoride diethyl ether is 1:2.1:0.2.

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