Fluorophilic hydrophobic functional monomer, synthesis method and application thereof, and detection electrode and preparation method thereof

Abstract

The present application relates to the fields of organic chemistry and environmental science and technology, and particularly relates to a fluorophilic hydrophobic functional monomer and a synthesis method and application thereof, and a fluorine-containing compound detection electrode based on the functional monomer and a preparation method thereof. The chemical structure of the fluorophilic hydrophobic functional monomer comprises pyrrole-3-carboxylic acid and fluorine-regulated polyalcohol bonded with the pyrrole-3-carboxylic acid. By introducing a long carbon fluoride chain into the basic functional monomer, the fluorophilic property and the hydrophobic property of the monomer to fluorine-containing compounds are significantly improved. Therefore, the present application uses pyrrole-3-carboxylic acid, a derivative of pyrrole, as a basic functional monomer, bonds fluorine-regulated polyalcohol to pyrrole-3-carboxylic acid, and synthesizes a new functional monomer with fluorophilic hydrophobic function. The functional monomer simultaneously uses the amine group in the pyrrole ring which has affinity to perfluorinated compounds and unique fluorine-fluorine interaction force to realize specific capture of fluorine-containing organic molecules. The perfluorinated compound detection method based on the functional monomer can avoid interference caused by sample matrix.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of organic chemistry and environmental science and technology, and particularly relates to a fluorophilic hydrophobic functional monomer and a synthesis method and application thereof, and a fluorine-containing compound detection electrode based on the functional monomer and a preparation method thereof. BACKGROUND

[0002] Perfluorinated compounds (PFAS) are a class of fluorine-containing chemicals with extremely high chemical stability and corrosion resistance, and are widely used in industry, firefighting, household and personal care products. Due to their environmental persistence and bioaccumulation, PFAS poses a serious threat to the environment and human health. For example, PFAS has been shown to have negative effects on the liver, immune system and reproductive system. Therefore, it is crucial to accurately identify, adsorb, remove and detect perfluorinated compounds.

[0003] Currently, the main technology for detecting PFAS is liquid chromatography-mass spectrometry (LC-MS / MS), which is widely used for PFAS detection due to its high sensitivity and specificity. However, LC-MS / MS equipment is expensive, complex to operate, and requires a long analysis time, which limits its application in on-site rapid detection and large-scale screening. In this context, electrochemical technology has become a research focus as an alternative solution due to its low cost, simple operation and suitability for on-site detection.

[0004] In the field of electrochemical sensing, due to the electrochemical inertness of perfluorinated compounds, efficient identification and detection of perfluorinated compounds in different environmental media is a difficult problem. Currently, molecularly imprinted polymers (MIPs) are widely used for specific recognition of PFAS. By synthesizing imprinted polymers with specific pore structures on conductive substrates, specific recognition of target molecules can be achieved. However, according to existing research, the recognition of MIPs for perfluorinated compounds mainly relies on hydrogen bond interactions provided by hydrophilic groups such as carboxyl or sulfonic acid groups at the end of the molecule, or in its ionic state (e.g. perfluorooctanoic acid, pKa≈3.7,) is captured by cationic recognition groups through electrostatic interactions. However, these two types of interaction forces are ubiquitous in nature and can easily interfere with detection.

[0005] Therefore, the prior art still needs to be improved and developed. SUMMARY

[0006] In view of the deficiencies of the prior art described above, the purpose of the present application is to provide a fluorophilic hydrophobic functional monomer and a synthesis method and application thereof, and a detection electrode and a preparation method thereof, aiming to overcome the problem that current recognition, adsorption, removal and detection of perfluorinated compounds rely on hydrogen bonds or electrostatic interactions, which are easily disturbed by external factors, thereby making it difficult to be applied in practice.

[0007] The technical scheme of the present application is as follows:

[0008] A fluorophilic hydrophobic functional monomer comprises pyrrole-3-carboxylic acid and a fluorine-tuned polyol bonded with the pyrrole-3-carboxylic acid; the chemical structural formula of the fluorophilic hydrophobic functional monomer is as follows:

[0009] wherein n is an integer greater than or equal to 1.

[0010] The fluorophilic hydrophobic functional monomer, wherein the ratio of the length of the fluorocarbon chain to the length of the hydrocarbon chain in the fluorine-tuned polyol is (6-12):2.

[0011] A synthesis method of a fluorophilic hydrophobic functional monomer, comprising the steps of:

[0012] Mixing pyrrole-3-carboxylic acid with an organic solvent to obtain a pyrrole-3-carboxylic acid solution;

[0013] Adding 1-ethyl-3-(3-dimethylaminopropyl) carbodiimide and 4-dimethylaminopyridine to the pyrrole-3-carboxylic acid solution and stirring to obtain a mixed solution;

[0014] Mixing the mixed solution with a fluorine-tuned polyol, and performing esterification to obtain the fluorophilic hydrophobic functional monomer.

[0015] The synthesis method of the fluorophilic hydrophobic functional monomer, wherein the molar ratio of the pyrrole-3-carboxylic acid to the fluorine-tuned polyol is (1-2):(1-2).

[0016] The synthesis method of the fluorophilic hydrophobic functional monomer, wherein the molar ratio of the 1-ethyl-3-(3-dimethylaminopropyl) carbodiimide to the 4-dimethylaminopyridine is (20-25):(1-2).

[0017] Application of a fluorophilic hydrophobic functional monomer in electrochemical detection of perfluorinated compounds.

[0018] A detection electrode comprising a conductive substrate and an F-pyrrole imprint polymer layer disposed on the conductive substrate; the F-pyrrole imprint polymer layer is obtained by in-situ polymerization of the fluorophilic hydrophobic functional monomer.

[0019] The detection electrode, wherein the conductive substrate comprises one of a screen-printed electrode, a glassy carbon electrode, a carbon electrode, a gold electrode, and a platinum electrode.

[0020] A preparation method of a detection electrode, comprising the steps of:

[0021] Mixing a fluorophilic hydrophobic functional monomer, a template molecule, and a supporting electrolyte with a solvent, and after ultrasonic treatment and pH adjustment, obtaining a polymerization solution;

[0022] immersing the conductive substrate into the polymerization solution, and electrochemically polymerizing to obtain a modified conductive substrate;

[0023] eluting the template molecules in the modified conductive substrate to obtain a detection electrode.

[0024] The preparation method of the detection electrode, wherein the template molecules comprise one or more of perfluorononanoic acid, perfluoropentane sulfonic acid, perfluorooctane sulfonic acid, and perfluorooctanoic acid; and / or the supporting electrolyte comprises one or more of tetrabutylammonium fluorosulfate and lithium perchlorate.

[0025] Beneficial effects: The present application provides a fluorophilic hydrophobic functional monomer, a synthesis method and application thereof, a detection electrode and a preparation method thereof. The fluorophilic hydrophobic functional monomer comprises pyrrole-3-carboxylic acid and a fluorine-regulated polyol bonded to the pyrrole-3-carboxylic acid. By introducing a long carbon fluoride chain into the functional monomer, the fluorophilic and hydrophobic properties of the monomer to fluorine-containing compounds can be significantly improved. By using pyrrole-3-carboxylic acid, a derivative of pyrrole, as a backbone functional monomer, and by introducing an amine group into the pyrrole ring, which has an affinity for perfluorinated compounds, the monomer has the ability to bind perfluorinated compounds. By directly bonding a fluorine-regulated polyol to pyrrole-3-carboxylic acid, 3-[2-(perfluorooctyl) ethoxycarbonyl] pyrrole, referred to as F-pyrrole, is synthesized, which is the fluorophilic hydrophobic functional monomer. By changing the length of the carbon fluoride chain in F-pyrrole, the affinity of the monomer to different perfluorinated compounds and its hydrophobicity can be controlled. The fluorophilic hydrophobic functional monomer can capture fluorine-containing organic molecules by using unique fluorine-fluorine interaction forces, avoiding interference from other interaction forces, thereby achieving efficient processing of fluorine-containing compounds and ensuring the effectiveness and accuracy of the fluorine-containing compounds in environmental detection. In addition, the functional monomer can also be used for efficient processing of fluorine-containing compounds, thereby improving the selectivity and removal efficiency in environmental analysis and pollutant removal. BRIEF DESCRIPTION OF DRAWINGS

[0026] Figure 1 Chemical reaction equation schematic diagram for synthesizing the fluorophilic hydrophobic functional monomer in Example 1 of the present application;

[0027] Figure 2 F-pyrrole prepared in Example 1 1 H NMR spectrum;

[0028] Figure 3 F-pyrrole prepared in Example 1 19 F NMR spectrum;

[0029] Figure 4 Mass spectrum of F-pyrrole prepared in Example 1

[0030] Figure 5The HPLC spectrum of F-pyrrole obtained in Example 1;

[0031] Figure 6 This is a schematic diagram illustrating the electrochemical preparation of the detection electrode and its application in the detection of PFNA in Example 1;

[0032] Figure 7 This is a data graph showing the electropolymerization of F-pyrrole using cyclic voltammetry in Example 1;

[0033] Figure 8 The graph shows the DPV current response data of F-PIP@SPE after adding different concentrations of PFNA;

[0034] Figure 9 The image shows a solid-phase extraction column using F-pyrrole as an adsorbent and the removal effect of the solid-phase extraction column on PFNA.

[0035] Figure 10 Transmission electron microscope images of F-pyrrole with ethanol and water as solvents, respectively;

[0036] Figure 11 This is a scanning electron microscope image;

[0037] Figure 12 This is a contact angle test diagram;

[0038] Figure 13 This is a comparison chart of the DPV signal restored after use and the previous signal for the same F-PIP@SPE.

[0039] Figure 14 A comparison chart showing the recovery status and signal changes of three different F-PIP@SPEs after a single use;

[0040] Figure 15 A graph showing the number of times F-PIP@SPE can be reused and the resulting signal changes;

[0041] Figure 16 The graph shows the current signal changes of the same F-PIP@SPE after 0, 5, 10, 15 and 30 days of storage. Detailed Implementation

[0042] This invention provides a fluorophilic hydrophobic functional monomer, its synthesis method and application, and a detection electrode and its preparation method. To make the objectives, technical solutions, and effects of this invention clearer and more explicit, the invention is further described in detail below. It should be understood that the specific embodiments described herein are merely illustrative of the invention and are not intended to limit the invention.

[0043] Those skilled in the art will appreciate that unless otherwise defined, all terms (including technical and scientific terms) used herein have the same meaning as commonly understood by one of ordinary skill in the art in the field of the application. It will be further understood that terms, such as those defined in commonly used dictionaries, should be interpreted as having a meaning that is consistent with their meaning in the context of the specification and relevant art and should not be interpreted in an idealized or overly formal sense unless expressly so defined herein.

[0044] One of the distinguishing features of PFAS from other pollutants is the abundance of carbon-fluorine (C-F) bonds. Fluorine-fluorine interaction (F-F interaction) is an interaction force that occurs between fluorine-containing compounds, and the energy of the F-F interaction is approximately between 1 and 20 kcal / mol, depending on the length of the carbon-fluorine chain, but it is undoubtedly sufficient to enable fluorine-containing organic molecules to be captured by a fluorine-containing organic layer.

[0045] Based on this, the present application provides a fluorophilic hydrophobic functional monomer, comprising pyrrole-3-carboxylic acid and a fluorine telomer alcohol bonded to the pyrrole-3-carboxylic acid; the chemical structure of the fluorophilic hydrophobic functional monomer is as follows:

[0046] wherein n is an integer greater than or equal to 1.

[0047] In this embodiment, by introducing a long carbon-fluorine chain into the functional monomer, the fluorophilicity and hydrophobicity of the monomer to fluorine-containing compounds can be significantly improved. By using pyrrole-3-carboxylic acid, a derivative of pyrrole, as the backbone functional monomer, the pyrrole ring contains an amine group that has affinity for PFAS, enabling it to bind PFAS, and by directly bonding a fluorine telomer alcohol (FTOH) to the pyrrole-3-carboxylic acid, 3-[2-(perfluorooctyl)ethoxycarbonyl]pyrrole, referred to as F-pyrrole, is synthesized, which is the fluorophilic hydrophobic functional monomer. At the same time, by changing the length of the carbon-fluorine chain in F-pyrrole, the affinity of the monomer to different PFAS, as well as the hydrophobicity of the monomer, can be controlled. The fluorophilic hydrophobic functional monomer obtained uses a unique F-F interaction to capture fluorine-containing organic molecules, avoiding interference from other interaction forces in detection, thereby achieving efficient processing capability for PFAS and ensuring its effectiveness and accuracy in environmental detection.

[0048] In some embodiments, the ratio of the length of the carbon-fluorine chain to the length of the carbon-hydrogen chain in the fluorine telomer alcohol is (6-12):2. By adjusting the ratio of the length of the carbon-fluorine chain to the length of the carbon-hydrogen chain in the fluorine telomer alcohol, the affinity of the fluorophilic hydrophobic functional monomer to different PFAS, as well as the hydrophobicity of the fluorophilic hydrophobic functional monomer, can be adjusted. Specifically, the longer the carbon-fluorine chain, the stronger the affinity to PFAS with longer carbon-fluorine chains, and the stronger the hydrophobicity.

[0049] In a preferred embodiment, the ratio of the length of the carbon-fluorine chain to the length of the carbon-hydrogen chain in the fluorine-modified polyol is 6:2 or 8:2.

[0050] Specifically, the fluorine-modified polyol includes but is not limited to 8:2 perfluoro- guivacol, 6:2 perfluoro-guivacol.

[0051] In addition, the present application also provides a method for synthesizing the fluorophilic hydrophobic functional monomer, comprising the steps of:

[0052] Step S10: mixing pyrrole-3-carboxylic acid with an organic solvent to obtain a pyrrole-3-carboxylic acid solution;

[0053] Step S20: adding 1-ethyl-3-(3-dimethylaminopropyl) carbodiimide and 4-dimethylamino pyridine to the pyrrole-3-carboxylic acid solution and stirring to obtain a mixed solution;

[0054] Step S30: mixing the mixed solution with a fluorine-modified polyol to obtain a fluorophilic hydrophobic functional monomer through esterification.

[0055] In the present embodiment, pyrrole-3-carboxylic acid is selected as the basic skeleton functional monomer, which can be used as a functional monomer for electrochemical polymerization reaction and can be modified in situ on different substrate materials. Therefore, by using pyrrole-3-carboxylic acid, a fluorine-modified polyol is directly bonded to pyrrole-3-carboxylic acid through one-step esterification to synthesize 3-[2-(perfluorooctyl) ethoxycarbonyl] pyrrole (F-pyrrole). The amine group on the pyrrole ring in F-pyrrole has affinity for perfluorinated compounds, providing the ability to bind perfluorinated compounds, while the fluorine-modified polyol bonded to pyrrole-3-carboxylic acid can form fluorine-fluorine interaction force with perfluorinated compounds to achieve specific capture of perfluorinated compounds, avoiding interference from other interaction forces to detection, thereby achieving efficient processing capability of fluorine-containing compounds and ensuring high selectivity and accuracy in environmental detection. At the same time, the method for synthesizing the fluorophilic hydrophobic functional monomer is generally carried out at room temperature, the process is simple and the operation difficulty is low, which is conducive to large-scale production.

[0056] Specifically, the method for synthesizing the fluorophilic hydrophobic functional monomer specifically comprises the steps of: dissolving pyrrole-3-carboxylic acid in a suitable organic solvent (such as acetonitrile), then adding 1-ethyl-3-(3-dimethylaminopropyl) carbodiimide and 4-dimethylamino pyridine and stirring at room temperature until all solutes are completely dissolved, then adding a fluorine-modified polyol and continuing to stir the mixture for 24 hours to complete the esterification reaction; after the reaction is completed, the solvent is removed, the crude mixture is collected, the crude mixture is washed with Milli-Q water to remove unreacted substances and by-products, and then the target product is purified by silica gel column chromatography to obtain the fluorophilic hydrophobic functional monomer in the form of a light yellow powder solid.

[0057] In some embodiments, the molar ratio of the pyrrole-3-carboxylic acid to the fluorine-modified polyol is (1-2):(1-2). The excess of one raw material can improve the efficiency of esterification reaction, and efficiently prepare the fluorophilic hydrophobic functional monomer.

[0058] In a preferred embodiment, the molar ratio of the pyrrole-3-carboxylic acid to the fluorine-modified polyol is 1:1, which can save the cost of raw materials.

[0059] In some embodiments, the molar ratio of the 1-ethyl-3-(3-dimethylaminopropyl) carbodiimide to the 4-dimethylaminopyridine is (20-25):(1-2). The 1-ethyl-3-(3-dimethylaminopropyl) carbodiimide and the 4-dimethylaminopyridine are mixed with the pyrrole-3-carboxylic acid solution in the molar ratio, which is conducive to the subsequent esterification reaction of the pyrrole-3-carboxylic acid and the fluorine-modified polyol to obtain the fluorophilic hydrophobic functional monomer.

[0060] In a preferred embodiment, the molar ratio of the 1-ethyl-3-(3-dimethylaminopropyl) carbodiimide to the 4-dimethylaminopyridine is 25:2.

[0061] In addition, the present application also provides a use of the fluorophilic hydrophobic functional monomer for electrochemical detection of perfluorinated compounds.

[0062] In the present embodiment, the fluorophilic hydrophobic functional monomer can capture perfluorinated compounds through fluorine-fluorine interaction force between the fluorophilic hydrophobic functional monomer and the perfluorinated compounds, and the length of the carbon-fluorine chain in the fluorophilic hydrophobic functional monomer can be adjusted according to the length of the carbon-fluorine chain in the perfluorinated compounds, so as to adjust the affinity and hydrophobicity of the fluorophilic hydrophobic functional monomer to different perfluorinated compounds, realize efficient treatment of fluorine-containing compounds, and ensure the effect and accuracy in environmental detection.

[0063] In some embodiments, the F-pyrrole can be filled into a solid phase extraction column as an adsorbent to prepare a solid phase extraction column for adsorbing and removing perfluorinated compounds.

[0064] In a preferred embodiment, a solid phase extraction column is prepared by using the F-pyrrole as an adsorbent and glass beads as a filling layer.

[0065] In addition, the present application also provides a detection electrode, which comprises a conductive substrate and an F-pyrrole imprinted polymer layer disposed on the conductive substrate; the F-pyrrole imprinted polymer layer is obtained by in-situ polymerization of the fluorophilic hydrophobic functional monomer.

[0066] In the embodiment, the fluorophilic hydrophobic functional monomer can be conveniently in-situ polymerized on different conductive substrates by electrochemical in-situ method; the fluorophilic hydrophobic functional monomer and template molecules are used to directly synthesize a F-pyrrole imprinted polymer (F-PIP) layer on a conductive substrate by cyclic voltammetry, so as to realize the characteristics of convenient transportation and use by using a detection electrode, and in combination with a micro electrochemical workstation, the effect of in-situ detection of PFNA-containing pollution can also be achieved.

[0067] In some embodiments, the conductive substrate includes but is not limited to one of a screen-printed electrode, a glassy carbon electrode, a carbon electrode, a gold electrode, and a platinum electrode. In the present application, pyrrole-3-carboxylic acid is selected as a basic functional monomer skeleton, which can undergo an electrochemical polymerization reaction, so that the fluorophilic hydrophobic functional monomer can be directly in-situ modified on different substrate materials.

[0068] In a preferred embodiment, a screen-printed electrode is selected as the conductive substrate.

[0069] In addition, the present application also provides a preparation method of a detection electrode, including the steps of:

[0070] Step S100: mixing a fluorophilic hydrophobic functional monomer, a template molecule, and a supporting electrolyte with a solvent, and after ultrasonic treatment and pH adjustment, obtaining a polymerization solution;

[0071] Step S200: immersing a conductive substrate in the polymerization solution, and after electrochemical polymerization, obtaining a modified conductive substrate;

[0072] Step S300: eluting the template molecule in the modified conductive substrate, and obtaining a detection electrode.

[0073] In the embodiment, the fluorophilic hydrophobic functional monomer can be conveniently in-situ polymerized on different conductive substrates by electrochemical in-situ method; by using the fluorophilic hydrophobic functional monomer and the template molecule, the F-pyrrole imprinted polymer (F-PIP) is directly synthesized on the conductive substrate by cyclic voltammetry, after eluting the template molecule, the polymer layer with strong recognition ability to PFNA is finally obtained, realizing the characteristics of convenient transportation and use by using the detection electrode, and in combination with the micro electrochemical workstation, the in-situ detection effect of the pollution containing PFNA can also be achieved. Moreover, the detection electrode modified with the fluorophilic hydrophobic functional monomer or the polymer modified with the fluorophilic hydrophobic functional monomer can extract, concentrate and enrich the perfluorinated compounds in the water sample, ensuring the high efficient processing capacity of the technology on the perfluorinated compounds in the water sample processing. In addition, the detection electrode can be used for electrochemical detection of the concentration of perfluorinated compounds in different environmental media, and the effect and accuracy thereof in environmental detection are ensured.

[0074] Specifically, the preparation method of the detection electrode specifically comprises the following steps: dissolving F-pyrrole, a template molecule and a supporting electrolyte in a suitable solvent (such as a methanol-water solution, an ethanol-water solution, an acetonitrile-water solution, etc.), and performing ultrasonic treatment, then adding NH4OH to adjust the pH, and finally removing the gas in the solution with N2 gas to obtain a polymerization solution. The conductive substrate is connected to the electrochemical workstation and immersed in the above polymerization solution, then cyclic voltammetry (CV) is used for electro-polymerization to obtain a modified conductive substrate, which is thoroughly washed with water and dried under N2 flow; then the modified conductive substrate is soaked in an acetonitrile / methanol solvent containing NH4OH, and shaken at 30°C to completely remove PFNA, then the electrode is washed with ultrapure water to remove residual eluent, and dried with nitrogen gas, finally the modified conductive substrate is placed in an oven and dried at 60°C for 10 minutes to remove any organic solvent adsorbed in the polymer coating, thereby obtaining the detection electrode.

[0075] In some embodiments, the template molecule comprises one or more of perfluorononanoic acid (PFNA, C8F 17 COOH), perfluoropentane sulfonic acid (PFHxS), perfluorooctane sulfonic acid (PFOS), perfluorooctanoic acid (PFOA); and / or, the supporting electrolyte comprises one or more of tetrabutylammonium fluorosulfate, lithium perchlorate.

[0076] Specifically, after synthesizing the polymer, a specific method is needed to elute the template molecule, so as to obtain a molecularly imprinted polymer with the same pore structure as the target analyte, i.e. F-pyrrole imprinted polymer.

[0077] The following examples are further provided to illustrate the present application in detail. It should be understood that the following examples are only used to further illustrate the present application and cannot be understood as limiting the scope of the present application. Some non-essential improvements and adjustments made by those skilled in the art according to the above content of the present application are within the scope of the present application.

[0078] Example 1

[0079] The present example provides a fluorophilic hydrophobic functional monomer and a detection electrode, and electrochemically detects the same, including the following:

[0080] As shown in Figure 1 , the steps for synthesizing the fluorophilic hydrophobic functional monomer (i.e., 3-[2-(perfluorooctyl)ethoxycarbonyl]pyrrole, referred to as F-pyrrole) include:

[0081] 1) adding 5mM pyrrole-3-carboxylic acid in a 100mL acetonitrile (MeCN) solution;

[0082] 2) adding 1-ethyl-3-(3-dimethylaminopropyl)carbodiimide (EDC, 5mM) and 4-dimethylaminopyridine (DMAP, 0.4mM) to the above solution;

[0083] 3) stirring the solution at room temperature for 30 minutes to ensure complete dissolution of pyrrole-3-carboxylic acid;

[0084] 4) then adding 8:2 perfluorooctanol (8:2-FTOH, 5mM) and continuing to stir the mixture for 24 hours to complete the esterification reaction;

[0085] 5) after the reaction is completed, remove the solvent and collect the crude mixture. Wash the crude mixture with Milli-Q water to remove unreacted substances and by-products; purify the target product by silica gel column chromatography, and finally obtain a light yellow powder solid (purity greater than 98%), i.e., F-pyrrole. The nuclear magnetic resonance hydrogen spectrum of F-pyrrole: δ H (400MHz, CDCl3) 2.57 (2H, tt, J = 18.4, 6.4 Hz, H-10), 4.55 (2H, t, J = 6.6 Hz, H-9), 6.67-6.68 (1H, m, H-5), 6.78 (1H, q, J = 2.4 Hz, H-5), 7.45-7.46 (1H, m, H-3), 8.53 (1H, s, NH). The nuclear magnetic resonance hydrogen spectrum of F-pyrrole is shown in Figure 2 ; The nuclear magnetic resonance fluorine spectrum of F-pyrrole: δ F(377MHz, CDCl3) -126.07(2F,m), -123.51(2F,m), -122.69(2F,m), -121.89(4F,m), -121.61(2F,m), -113.50(2F,m), -80.744(3F,m). The NMR fluorine spectrum of F-pyrrole is as follows: Figure 3 As shown; mass spectrometry and high performance liquid chromatography are respectively as follows. Figure 4 and Figure 5 As shown, the relative molecular mass of the target product calculated from the mass spectrometry of F-pyrrole is: MS(ESI) m / z = 556.8, which is very close to the theoretical relative molecular mass of 557.03. According to the high-performance liquid chromatography (HPLC) chromatogram, the peak area at retention time 2.726 accounts for 98.133% of the total peak area. This indicates that the purity of F-pyrrole after purification reaches >98%.

[0086] like Figure 6 and Figure 7 As shown, the steps for preparing the detection electrode include:

[0087] 1) Dissolve 10 mM F-pyrrole (functional monomer), 5 mM PFNA (template molecule) and 10 mM NBu4PF6 (supporting electrolyte) in 10 mL MeCN-H2O solution (8:2, v / v) and sonicate for 3 minutes. Then add 2 μL / mL NH4OH to adjust the pH. Finally, remove the gas in the solution with N2 gas and treat for 10 minutes to prepare the polymerization solution.

[0088] 2) Connect the screen-printed electrode (SPE) to the electrochemical workstation and immerse it in the above polymerization solution to perform electropolymerization using cyclic voltammetry (CV). Figure 7 To use cyclic voltammetry (CV), in-situ electrochemical polymerization of F-pyrrole molecularly imprinted polymers was performed on screen-printed electrodes. Figure 7 a) and non-imprinted polymers ( Figure 7 (b) Cyclic voltammetry shows the relationship between current and voltage. As the voltage increases, the current remains stable between -0.3V and 0.4V, then increases sharply, and an oxidation peak appears around +0.9V, which can be attributed to the oxidation of amine groups. The current continues to rise after +0.9V, indicating that F-pyrrole is undergoing a polymerization reaction.

[0089] The CV parameters were set as follows: potential range from -0.3 V to 1.2 V (versus Ag), scan rate of 50 mV / s, 10 cycles, and the resulting modified screen-printed electrode was referred to as F-PIP(PFNA)@SPE (at this point the template molecules were not removed), which was thoroughly rinsed with water and dried under a stream of N2. The F-PIP(PFNA)@SPE was immersed in acetonitrile containing 0.1% NH4OH at 30 °C for 15 min with shaking (100 rpm) to completely remove the PFNA, and then the electrode was rinsed with ultrapure water to remove the residual eluent and dried gently with nitrogen. Finally, the modified screen-printed electrode was placed in an oven at 60 °C for 10 min to remove any organic solvents adsorbed in the polymer coating, and the resulting electrode was referred to as F-PIP@SPE (i.e. the template was removed) and could be stored under safe conditions without the need for strict environmental controls.

[0090] As shown in Figure 6 , the F-PIP@SPE prepared was subjected to electrochemical detection of PFNA, including the following steps:

[0091] 1) The prepared F-PIP@SPE was connected to an electrochemical workstation and then immersed in an aqueous solution containing different concentrations of PFNA for incubation for 15 min. After removal, the surface was rinsed with water and then dried with nitrogen;

[0092] 2) The incubated F-PIP@SPE was immersed in a supporting electrolyte, and the change in current value was recorded using differential pulse voltammetry (DPV). The change in DPV current of the F-PIP@SPE in different concentrations of PFNA solution is shown in the left graph of Figure 8 ;

[0093] 3) The composition of the supporting electrolyte was 5 mM ferrocenecarboxylic acid, 2 μL / mL NH4OH and 1 μL / mL HC1;

[0094] 4) The differential pulse voltammetry was performed at a potential range of -0.1 V to 0.5 V (versus Ag) with an amplitude of 25 mV and a pulse width of 0.025 s;

[0095] 5) The change in current value was plotted against the concentration of PFNA to obtain a standard curve, as shown in the right graph of Figure 8 ;

[0096] 6) For unknown concentrations of PFNA solution, the concentration can be calculated inversely from the standard curve after measuring the current value.

[0097] Example 2

[0098] The F-pyrrole prepared in Example 1 was filled into a solid phase extraction column as an adsorbent to prepare a solid phase extraction column for adsorbing and removing perfluorinated compounds. Taking PFNA as an example, the wastewater containing PFNA was passed through the column, and the concentration of PFNA in the filtrate was detected to evaluate the removal rate of the column to PFNA. In actual operation, due to the superhydrophobicity of F-pyrrole, the PFNA aqueous solution is not easy to pass through the F-pyrrole adsorption layer. Therefore, glass beads were added as a filler to the adsorption layer to increase the contact area of F-pyrrole with PFNA and improve the removal efficiency.

[0099] Specifically, as shown in Figure 9 , a solid phase extraction column was prepared with F-pyrrole as an adsorbent and glass beads as a filler layer, as shown in the left graph of Figure 9 , and the right graph of Figure 9 shows the removal effect of the solid phase extraction column on PFNA; wherein the detection of the concentration of PFNA was completed by LC-MS / MS.

[0100] Example 3

[0101] The F-pyrrole prepared in Example 1 was characterized by transmission electron microscopy, as shown in Figure 10 , the characterization results show that when ethanol is used as a solvent, the morphology of F-pyrrole presents regular spherical particles; and when water is used as a solvent, the particle size of the particles is significantly increased, and the maximum can reach 6 μm, and shows an aggregated morphology. This indicates that F-pyrrole is more inclined to dissolve in alcohol solvents, and is not easy to dissolve in water.

[0102] Example 4

[0103] The modified electrodes prepared in Example 1 (including F-PIP(PFNA)@SPE, F-PIP@SPE) were characterized by scanning electron microscopy, as shown in Figure 11 , wherein Figure 11 a is a blank SPE, b is a F-pyrrole molecularly imprinted polymer (containing PFNA) modified SPE, and c is a F-pyrrole molecularly imprinted polymer (not containing PFNA) modified SPE. It can be found that after the electro-polymerization of F-pyrrole, the surface of the screen-printed electrode has changed obviously, and the particle size has increased significantly.

[0104] Example 5

[0105] The modified electrode prepared in Example 1 was subjected to contact angle test, and the results are shown in Figure 12 , and Figure 12a is blank SPE, b is F-pyrrole molecularly imprinted polymer (containing PFNA) modified SPE, c is F-pyrrole molecularly imprinted polymer (not containing PFNA) modified SPE; on the blank electrode, the angle between the water droplet and the surface of the SPE is about 44.5 degrees; and after the polymer layer is modified with poly-F-pyrrole, the angle is significantly increased to about 157 degrees. This indicates that the polymer layer has superhydrophobicity. After removing the PFNA, the angle slightly decreases to about 140 degrees. This is because the PFNA itself also has a certain degree of hydrophobicity.

[0106] Example 6

[0107] The robustness of the F-PIP@SPE prepared in Example 1 in detection was tested, Figure 13 The cycle stability of the F-PIP@SPE was demonstrated, Figure 14 The detection performance change of the F-PIP@SPE after repeated use and different storage times was demonstrated. All test results show that the sensor has good analytical performance and robustness.

[0108] Figure 15 The number of times of repeated use of the F-PIP@SPE and the change of the signal thereof, the results show that after the sixth use, the signal has a large deviation, indicating that the F-PIP@SPE can be stably used for 6 times. Figure 16 The current signal change of the same F-PIP@SPE after storage for 0 days, 5 days, 10 days, 15 days and 30 days.

[0109] In summary, the present application provides a fluorophilic hydrophobic functional monomer and a synthesis method and application thereof, a detection electrode and a preparation method thereof. The fluorophilic hydrophobic functional monomer comprises pyrrole-3-carboxylic acid and a fluorine-regulated polyol bonded to the pyrrole-3-carboxylic acid. By introducing a long carbon fluoride chain into the functional monomer, the fluorophilic and hydrophobic properties of the monomer to fluorine-containing compounds can be significantly improved. By using pyrrole-3-carboxylic acid, a derivative of pyrrole, as a skeleton functional monomer, the pyrrole ring contains an amine group that has affinity for perfluorinated compounds, so that it has the ability to bind perfluorinated compounds. By directly bonding the fluorine-regulated polyol to pyrrole-3-carboxylic acid, 3-[2-(perfluorooctyl) ethoxycarbonyl] pyrrole, referred to as F-pyrrole, is synthesized, which is the fluorophilic hydrophobic functional monomer. At the same time, by changing the length of the carbon fluoride chain in F-pyrrole, the affinity of the monomer to different perfluorinated compounds and its hydrophobicity can be controlled. The obtained fluorophilic hydrophobic functional monomer uses unique fluorine-fluorine interaction force to realize the capture of fluorine-containing organic molecules, avoids the interference of other interaction forces on detection, and thus realizes the efficient processing ability of fluorine-containing compounds, ensuring its effect and accuracy in environmental detection.

[0110] It is to be understood that the application is not limited to the examples described above, which can be modified or adapted in several ways by those skilled in the art without departing from the scope of the present application, as defined by the appended claims.

Claims

1. A fluorophilic hydrophobic functional monomer, characterized in that, The pyrrole-3-carboxylic acid and the fluorine-tuned polyol are linked by a chemical bond. ; wherein the ratio of carbon-fluorine chain length to carbon-hydrogen chain length in the fluorotelomer alcohol is (6-12):

2.

2. A method for synthesizing a fluoro-philic hydrophobic functional monomer according to claim 1, characterized in that, The method comprises the following steps: The pyrrole-3-carboxylic acid is mixed with an organic solvent to obtain a pyrrole-3-carboxylic acid solution; The 1-ethyl-3-(3-dimethylaminopropyl) carbodiimide and the 4-dimethylaminopyridine are added to the pyrrole-3-carboxylic acid solution and stirred to obtain a mixed solution; The mixed solution is mixed with the fluorine-tuned polyol to obtain the fluorophilic hydrophobic functional monomer through an esterification reaction.

3. The method of claim 2, wherein the fluoro-philic hydrophobic functional monomer is synthesized by the reaction of the compound of formula (2) with the compound of formula (3) in the presence of the base. The molar ratio of the pyrrole-3-carboxylic acid to the fluorine-tuned polyol is (1-2):(1-2).

4. The method of claim 2, wherein the fluoro-philic hydrophobic functional monomer is synthesized by the reaction of the compound of formula (2) with the compound of formula (3) in the presence of the base. The molar ratio of the 1-ethyl-3-(3-dimethylaminopropyl) carbodiimide to the 4-dimethylaminopyridine is (20-25):(1-2).

5. Use of the fluorophilic hydrophobic functional monomer of claim 1 in electrochemical detection of perfluorinated compounds, wherein the use is a non-disease diagnosis or treatment use.

6. A detection electrode, characterized by The F-pyrrole imprinted polymer layer is obtained by in-situ polymerization of the fluorophilic hydrophobic functional monomer of claim 1.

7. The detection electrode according to claim 6, characterized in that The conductive substrate is selected from one of a silk screen printed electrode, a carbon electrode, a gold electrode and a platinum electrode.

8. A method of preparing a test electrode as claimed in any one of claims 6-7, characterized in that, The method comprises the following steps: The fluorophilic hydrophobic functional monomer, the template molecule and the supporting electrolyte are mixed with a solvent, and after ultrasonic treatment and pH adjustment, a polymerization solution is obtained; The conductive substrate is immersed in the polymerization solution, and an electrochemical polymerization is performed to obtain a modified conductive substrate; The template molecule in the modified conductive substrate is eluted to obtain a detection electrode.

9. The method of claim 8, wherein the step of forming the detection electrode is performed by a method selected from the group consisting of: sputtering, vacuum deposition, and thermal evaporation. The template molecule is selected from one or more of perfluorononanoic acid, perfluoropentane sulfonic acid, perfluorooctane sulfonic acid and perfluorooctanoic acid; and / or, the supporting electrolyte is selected from one or more of tetrabutylammonium fluorosulfate and lithium perchlorate.

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