Water-soluble terphenyl [3] arene macrocyclic WTP3 and application thereof in paraquat detection

Abstract

The invention provides a water-soluble terphenyl [3] arene macrocyclic WTP3 and an application of the water-soluble terphenyl [3] arene macrocyclic WTP3 in paraquat detection. The invention designs and synthesizes a fluorescent molecule based on terphenyl aromatic hydrocarbon macrocycle, WTP3 has a remarkable fluorescence characteristic, and when paraquat is used as a detected object and WTP3 interacts with paraquat, fluorescence quenching can occur, so that high-sensitivity detection of paraquat is realized. The complexing constant Ka between WTP3 and paraquat is up to 2.4 * 10 < 8 > M <-1 >, the lowest detection limit is as low as 7.24 * 10 <-8 > M, and extremely high sensitivity is shown. The RGB value of the fluorescence photograph is analyzed through the smart phone APP to obtain G / B, and quantitative detection can be achieved by combining the G / B with the linear relation of the G / B and the paraquat solution. Compared with a traditional detection method, the fluorescence sensing system has the advantages of being easy and convenient to operate, rapid in response and the like, an efficient and environment-friendly new strategy is provided for on-site monitoring of highly toxic pesticide residues in environment water samples and agricultural products, and the fluorescence sensing system has important application value in the field of environment safety and food detection.

Description

Technical Field

[0001] This invention relates to a water-soluble terphenyl[3] aromatic macrocyclic WTP3, and also to the application of water-soluble terphenyl[3] aromatic macrocyclic WTP3 in the detection of paraquat, belonging to the field of organic fluorescent material detection. Background Technology

[0002] Paraquat (PQ), a highly effective broad-spectrum herbicide, is widely used due to its outstanding weed-controlling effect. However, its extremely high toxicity has also attracted widespread attention from the academic community and society. Numerous toxicological studies have shown that paraquat not only has extremely high lethal toxicity to humans and other mammals, but its environmental residues can also have profound negative impacts on ecosystems. Given the current global prevalence of paraquat abuse, establishing rapid, accurate, and convenient methods for paraquat detection, and developing corresponding functionalized detection materials, has become an important research topic in environmental monitoring and public safety. Although current molecular recognition technologies such as chromatography and spectroscopic detection can achieve quantitative detection of paraquat, these methods generally suffer from limitations such as expensive equipment, complex pretreatment, and long detection cycles. Therefore, how to overcome the limitations of traditional detection technologies while ensuring detection sensitivity and accuracy, and develop novel analytical methods that are easy to operate and low in cost, while also considering the specificity, stability, and reproducibility of the methods, remains a significant challenge and research hotspot in the field.

[0003] Based on the above research background and technical requirements, this invention innovatively proposes a fluorescence sensing system based on water-soluble terphenyl[3] aromatic macrocyclic WTP3 for the efficient detection of paraquat. The establishment of this detection method is mainly based on the following design concept: WTP3 molecules have a unique loose porous structure and electron-rich cavity characteristics. The three-dimensional cavity formed by its rigid skeleton can not only specifically bind to paraquat molecules through π-π stacking, but its peripheral negatively charged sulfonic acid groups can also generate electrostatic interactions with positively charged paraquat molecules, thereby realizing a dual recognition mechanism. Moreover, WTP3 molecules exhibit excellent fluorescence characteristics in aqueous solution. When it undergoes host-guest complexation with paraquat, it will cause a significant fluorescence quenching phenomenon. The change in this fluorescence signal shows a good linear relationship with the concentration of paraquat, providing a reliable basis for quantitative detection. Based on this, the present invention discloses for the first time a method for synthesizing water-soluble terphenyl[3] aromatic macrocyclic WTP3 and its application in paraquat detection. The detection system has significant advantages such as simple operation, fast response, good selectivity and high sensitivity, providing a new technical solution for the on-site detection of paraquat residues in environmental water samples and agricultural products. Summary of the Invention

[0004] The purpose of this invention is to provide a water-soluble terphenyl[3] aromatic macrocyclic WTP3; Another objective of this invention is to provide the application of the water-soluble terphenyl[3] aromatic macrocyclic WTP3 in the detection of paraquat.

[0005] The structural formula of the water-soluble terphenyl[3] aromatic macrocyclic WTP3 of this invention is as follows: .

[0006] The present invention provides a method for synthesizing water-soluble terphenyl[3] aromatic macrocyclic WTP3, comprising the following steps: (1) Synthesis of compound COOEt-TP3: Compound OH-TP3 and potassium carbonate were added to acetonitrile, heated to 75~85℃ and refluxed for 1~3 hours under N2 atmosphere, ethyl bromoacetate was added and refluxed for 45~50 hours, and after purification and drying, compound COOEt-TP3 was obtained. The structural formula of compound OH-TP3 is as follows: ; The structural formula of compound COOEt-TP3 is: The molar ratio of OH-TP3 to ethyl bromoacetate is 1:20 to 1:30; the molar ratio of OH-TP3 to potassium carbonate is 1:40 to 1:50.

[0007] (2) Synthesis of compound COOH-TP3: Compound COOEt-TP3 was dissolved in a mixture of tetrahydrofuran and sodium hydroxide solution and stirred at 60~70℃ for 10~15h. The tetrahydrofuran solvent was evaporated and the residue was dissolved in deionized water to form a clear and transparent solution and acidified with hydrochloric acid to pH 2~3 to precipitate. After filtration and drying, compound COOH-TP3 was obtained. The structural formula of compound COOH-TP3 is: The concentration of the sodium hydroxide solution was 20%; the volume ratio of tetrahydrofuran to sodium hydroxide solution was 1:1 to 1.5:1; and the mass-to-volume ratio of compound COOEt-TP3 to tetrahydrofuran was 0.01 to 0.02 g / mL.

[0008] (3) Synthesis of compound WTP3: Compound COOH-TP3 was added to ammonia water and reacted at room temperature for 4-6 hours. After filtration and drying, water-soluble terphenyl[3] aromatic macrocyclic WTP3 was obtained. The concentration of ammonia water was 25-28% and the mass-volume ratio of compound COOH-TP3 to ammonia water was 2-3 mg / mL.

[0009] The proton NMR spectra of compounds COOH-TP3 and WTP3 are shown below. Figure 1 , Figure 2 The correct synthesis of compounds COOH-TP3 and WTP3 can be confirmed by using proton NMR spectroscopy.

[0010] This invention provides the application of water-soluble terphenyl[3] aromatic macrocyclic WTP3 in the detection of paraquat (PQ).

[0011] The present invention provides a method for detecting paraquat using water-soluble terphenyl[3] aromatic macrocyclic WTP3, comprising the following steps: (1) Preparation of fluorescent test strips: Cut filter paper into strips, soak them in DMSO solution for 10-15 h, and air dry them to obtain test strips. Soak the test strips in WTP3 solution for 5-6 h and air dry them to obtain fluorescent test strips. (2) Detection of paraquat: Add the paraquat solution to be tested to the fluorescent test paper, take a fluorescent photo, analyze the RGB values ​​of the fluorescent photo through the smartphone APP color picker to obtain the G / B, and calculate the concentration of the paraquat solution to be tested by combining the linear relationship between G / B and the logarithm of the paraquat solution concentration. The concentration of paraquat is 1×10 -1 ~ 1×10 -6 Within the mol / L range, G / B exhibits a good linear relationship with the logarithm of paraquat solution concentration, as given by y = -0.08x + 0.22, where y is the G / B value, x is the logarithm of paraquat solution concentration (lg c, where c is the paraquat solution concentration in mol / L), and R... 2 =0.99.

[0012] Beneficial results of the present invention: The present invention innovatively uses water-soluble terphenyl[3] aromatic macrocyclic WTP3 as a fluorescent probe molecule, and successfully achieves efficient detection of paraquat. This detection system not only establishes a new method for high-sensitivity paraquat detection based on WTP3, but also shows through experiments that the complexation constant Ka between WTP3 and paraquat is as high as 2.4×10 8 M -1 This formed a very stable complex with a limit of detection (LOD) as low as 7.24 × 10⁻⁶. -8M exhibits extremely high sensitivity. Furthermore, the fluorescent test strip constructed based on this WTP3 is simple to operate. After treating the test strip in a specific solution, the paraquat solution to be tested is added, and the RGB values ​​of the fluorescence image are analyzed via a smartphone app to obtain the G / B ratio. Quantitative detection can be achieved by combining this with the linear relationship between the G / B ratio and the paraquat solution (R²=0.99). Quantitative detection via RGB value analysis using a smartphone app avoids reliance on complex instruments. This method is simple to operate, has a rapid response, and good selectivity, providing an efficient and environmentally friendly new strategy for on-site monitoring of highly toxic pesticide residues in environmental water samples and agricultural products. It also provides a new technical solution for the on-site detection of paraquat residues in environmental water samples and agricultural products. This research achievement opens up new avenues for the fluorescence sensing detection of environmental pollutants and is of great significance for promoting the development of environmental monitoring technology. Attached Figure Description

[0013] Figure 1 The proton NMR spectrum of compound COOH-TP3; Figure 2 Hydrogen spectrum of water-soluble terphenyl[3] aromatic macrocyclic WTP3; Figure 3 Fluorescence response of water-soluble terphenyl[3] aromatic macrocyclic WTP3 to paraquat; Figure 4 Linear fitting curve of water-soluble terphenyl[3] aromatic macrocyclic WTP3 against paraquat; Figure 5 The detection limit of water-soluble terphenyl[3] aromatic macrocyclic WTP3 for paraquat; Figure 6 The response of fluorescent test strips to different PQ solutions; Figure 7 A linear relationship was established for the detection of different PQ solutions using fluorescent test strips. Detailed Implementation

[0014] The following specific examples further illustrate the synthesis of the water-soluble terphenyl[3] aromatic macrocyclic WTP3 of the present invention and its application in the detection of paraquat.

[0015] Example 1: Synthesis of water-soluble terphenyl[3] aromatic macrocyclic WTP3 (1) Synthesis of compound OH-TP3: Referring to the literature Chen, J.; Chen, L.; Zhang, Y.; Zhao, L.; Dong, M.; Meng, Z.; Meng, Q.; Li, C. The effective taste masking of alkaloids by a water-soluble terphen[3]arene. Chemical Communications 2022, 58 (20), 3370-3373, 10.1039 / D2CC00040G, the compound OH-TP3 was synthesized as a grayish-white powder.

[0016] (2) Synthesis of compound COOEt-TP3: OH-TP3 (0.36 g, 0.4 mmol) was added to a two-necked flask, followed by acetonitrile solution (90 mL). Potassium carbonate (2.6 g, 18.8 mmol) was added under stirring. The mixture was heated to 80 °C and refluxed for 2 hours under a N2 atmosphere. Ethyl bromoacetate (1.67 g, 10 mmol) was then added, and reflux was continued for 48 hours. After the reaction was complete, the mixture was cooled to room temperature, inorganic salts were removed, and the filter cake was washed with dichloromethane (50 mL × 3). The cake was dried, filtered, rotary evaporated, and mixed. The crude product (petroleum ether / ethyl acetate (2:1)) was purified by column chromatography and collected in a two-necked flask. The product was then dissolved in a very small amount of dichloromethane by recrystallization, followed by the addition of petroleum ether to precipitate the product. After drying, 0.45 g of COOEt-TP3 was obtained as a pale yellow powder, with a yield of 60%.

[0017] (3) Synthesis of compound COOH-TP3: COOEt-TP3 (0.7 g, 1.5 mmol) was dissolved in a mixture of tetrahydrofuran (50 mL) and 20% sodium hydroxide aqueous solution (35 mL), and stirred at 65 °C for 12 hours. The tetrahydrofuran solvent was then removed by evaporation under vacuum. The residue was dissolved in deionized water (20 mL) to form a clear, transparent solution, and acidified with hydrochloric acid to pH 2-3. A large amount of white, cotton-like precipitate formed at the bottom. After filtration and drying, 0.49 g of the product COOH-TP3 was obtained as a white solid. Yield: 85%. Melting point: >300 °C; 1H NMR spectrum as shown. Figure 1 , 1H NMR (400 MHz, δ-DMSO, 298 K) δ / ppm: 7.35 (s, 12H), 6.85 (s, 6 H), 6.55 (s, 6 H), 4.68 (s, 12 H), 4.62 (s, 12 H), 3.98 (s, 6 H).

[0018] (4) Synthesis of compound WTP3 Compound COOH-TP3 (0.3 g, 0.18 mmol) was added to a reaction flask as a starting material, and ammonia water (120 mL, 25-28%) was used as a solvent. The reaction was carried out at room temperature for 6 h. After the reaction, the reaction solution was filtered and dried to obtain product WTP3, 0.23 g, as a white powder. Yield: 95%. Melting point: >300 ℃; 1H NMR spectrum as shown. Figure 2 , 1 H NMR (400 MHz, D2O) δ / ppm: 7.51 (s, 12 H), 7.07 (s, 6 H), 6.46 (s, 6 H), 4.48 (s, 12 H), 4.43 (s, 12H), 4.04 (s, 6 H), 1.72 (t, 16 H), 1.31 (t, 16 H).

[0019] The synthetic route is as follows: Example 2: Fluorescence response of water-soluble terphenyl[3] aromatic macrocyclic WTP3 to paraquat Water-soluble terphenyl[3] aromatic macrocyclic WTP3 exhibits certain fluorescence under excitation at 310 nm, but its fluorescence is quenched when paraquat (PQ) solution is added to WTP3. In order to study the fluorescence response performance of WTP3 to paraquat, water-soluble terphenyl[3] aromatic macrocyclic WTP3 (1×10 -5 PQ (1×10⁻⁶) was added dropwise to the solution of M. -3 In solution M, it was observed that with the addition of PQ solution, the fluorescence of WTP3 gradually decreased until it was completely quenched. Figure 3 This demonstrates that WTP3 exhibits fluorescence response to PQ, and is characterized by its simple operation and rapid response.

[0020] Through fitting analysis of the Benesi-Hildebrand (BH) linear equation, the complexation constant Ka between WTP3 and paraquat was calculated. Figure 4 Ka reaches 2.4×10 8 M -1This indicates that a very stable complex has formed between the two. Furthermore, the limit of detection (LOD) was calculated to be 7.24 × 10⁻⁶ using the 3σ / s method. -8 M ( Figure 5 The results showed that WTP3 exhibited extremely high sensitivity to paraquat.

[0021] Example 3: Fluorescence response of fluorescent test strip to PQ solution and detection of PQ solution. (1) Preparation of fluorescent test strip: Weigh 0.2572 g of PQ and prepare 1×10 PQ solution. -1 mol / L, and diluted with a series of gradient concentrations of 1×10 -2 ~1×10 -6 mol / L. Then weigh 0.0484 g of water-soluble terphenyl[3] aromatic macrocyclic WTP3 and prepare a water-soluble terphenyl[3] aromatic macrocyclic WTP3 solution (1×10 mol / L). -3 (mol / L). Subsequently, filter paper was cut to an appropriate size and soaked in DMSO solution for 12 h before air drying to obtain test strips. The test strips were then soaked in WTP3 solution for 6 h and air dried to obtain fluorescent test strips.

[0022] (2) Fluorescence response of the fluorescent test strip to PQ solution: When PQ solution is added to the fluorescent test strip, it can be observed that as the concentration of PQ solution increases, the fluorescence of the fluorescent test strip gradually weakens until it is quenched. Figure 6 ).

[0023] (3) Establishment of the linear relationship between the fluorescent test strip and PQ solution: The fluorescent test strip was used to detect PQ solution of different concentrations, and the fluorescence of the different concentrations was photographed. The RGB values ​​of the fluorescence photos were analyzed by the smartphone APP colorpicker, and the G / B ratio was obtained (Table 1). The linear relationship between the effect of WTP3 solution and PQ solution was established.

[0024] At a PQ concentration of 1×10 -1 ~ 1×10 -6 Within the mol / L range, the logarithm of G / B and PQ solution concentrations exhibits a good linear relationship (e.g., Figure 7 (b) The linear relationship is y = -0.08x + 0.22, where y is the G / B value, x is the logarithm of the paraquat solution concentration (lg c), and R 2 =0.99.

[0025] (3) Concentration detection of PQ solution: A solution with a concentration of 1×10⁻⁶ was prepared.-5 A mol / L PQ solution was added to a fluorescent test strip, and a fluorescence image was taken. The RGB values ​​of the fluorescence image were analyzed using a smartphone app called Color Picker. The G / B ratio was 0.612. Substituting this into a linear relationship, the concentration of the PQ solution was calculated to be 1.003 × 10⁻⁶. -5 mol / L, the detection results are accurate.

[0026] (4) Add an unknown concentration of PQ solution to the fluorescent test paper and take a fluorescence photograph. Analyze the RGB values ​​of the fluorescent photograph using a smartphone APP color picker. The G / B ratio is 0.45. Substitute this into the linear relationship and calculate x as -2.9. Based on the calculation, the concentration of the PQ solution is 1.259 × 10⁻⁶. -3 mol / L.

[0027] In summary, this invention successfully developed a novel fluorescent sensing system based on water-soluble terphenyl[3] aromatic macrocyclic WTP3, which can efficiently and selectively detect paraquat residues in the environment and agricultural products. Experimental results show that WTP3, with its unique molecular structure and electronic properties, can serve as a high-performance fluorescent sensor to achieve high-sensitivity detection of paraquat solutions, providing an important theoretical basis for the development of a supramolecular sensing platform based on water-soluble terphenyl[3] aromatic macrocyclic WTP3.

Claims

1. A water-soluble terphenyl[3] aromatic macrocyclic WTP3, with the following structure: 。 2. The method for synthesizing water-soluble terphenyl[3] aromatic macrocyclic WTP3 according to claim 1 includes the following steps: (1) Synthesis of compound COOEt-TP3: Compound OH-TP3 and potassium carbonate were added to acetonitrile, heated to 75~85℃ and refluxed for 1~3 hours under N2 atmosphere, ethyl bromoacetate was added and refluxed for 45~50 hours, and after purification and drying, compound COOEt-TP3 was obtained. The structural formula of compound OH-TP3 is: ； The structural formula of compound COOEt-TP3 is: (2) Synthesis of compound COOH-TP3: Compound COOEt-TP3 was dissolved in a mixture of tetrahydrofuran and sodium hydroxide solution and stirred at 60~70℃ for 10~15h. The tetrahydrofuran solvent was evaporated and the residue was dissolved in deionized water to form a clear and transparent solution and acidified with hydrochloric acid to pH 2~3 to precipitate. After filtration and drying, compound COOH-TP3 was obtained. The structural formula of compound COOH-TP3 is: (3) Synthesis of compound WTP3: Compound COOH-TP3 was added to ammonia water and reacted at room temperature for 4-6 h. After filtration and drying, water-soluble terphenyl[3] aromatic macrocyclic WTP3 was obtained.

3. The synthesis method according to claim 2, characterized in that: In step (1), the molar ratio of OH-TP3 to ethyl bromoacetate is 1:20~1:30; the molar ratio of OH-TP3 to potassium carbonate is 1:40~1:

50.

4. The synthesis method according to claim 2, characterized in that: In step (2), the concentration of sodium hydroxide solution is 20%; the volume ratio of tetrahydrofuran to sodium hydroxide solution is 1:1 to 1.5:1; and the mass-volume ratio of compound COOEt-TP3 to tetrahydrofuran is 0.01 to 0.02 g / mL.

5. The synthesis method according to claim 2, characterized in that: In step (3), the concentration of ammonia is 25-28%; the mass-to-volume ratio of compound COOH-TP3 to ammonia is 2-3 mg / mL.

6. The application of the water-soluble terphenyl[3] aromatic macrocyclic WTP3 according to claim 1 in the detection of paraquat.

7. The application according to claim 6, characterized in that: The method for detecting paraquat using water-soluble terphenyl[3] aromatic macrocyclic WTP3 includes the following steps: Preparation of fluorescent test strips: Cut filter paper into strips, soak them in DMSO solution for 10-15 h, and air dry them to obtain test strips. Soak the test strips in WTP3 solution for 5-6 h and air dry them to obtain fluorescent test strips. Detection of paraquat: The paraquat solution to be tested is dropped onto a fluorescent test strip, and a fluorescence photograph is taken. The RGB values ​​of the fluorescence photograph are analyzed to obtain the G / B ratio. Based on the linear relationship between G / B and the logarithm of the paraquat solution concentration, the concentration of the paraquat solution to be tested is calculated.

8. The application according to claim 7, characterized in that: Paraquat concentration at 1×10 -1 ~ 1×10 -6 Within the mol / L range, G / B exhibits a good linear relationship with the logarithm of paraquat solution concentration, as shown by the equation y = -0.08x + 0.22, where y is the G / B value, x is the logarithm of the paraquat solution concentration, and R0 is the logarithm of the paraquat solution concentration. 2 =0.99.

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