A zinc-based coordination polymer, a preparation method of a film and application of the film to fluorescent detection of ephedrine

Abstract

The present application relates to a kind of zinc-based coordination polymer and film preparation method and application fluorescent detection of sparteine.Polymer is three-dimensional zinc metal organic framework material, the frame is connected by binuclear zinc and organic ligand to have one-dimensional pore, chemical formula is {NH2(CH3)2·[Zn (TDA)]·DMF·3C2H5OH} n};With fluorescence emission peak at 400nm.It is prepared by hydrothermal reaction by zinc iodide and 4,4'‑(1H‑1,2,4‑triazole‑3,5‑diyl) dibenzoic acid in DMF and ethanol mixed solvent, add acetic acid as regulator.The zinc-based coordination polymer and film prepared by the present application have specific fluorescence recognition function, can quickly and conveniently detect sparteine in water and other solutions, the detection limit is as low as 5.26×10 ‑6 M, high sensitivity and can be recycled.And preparation process is simple, application portable, not dependent on expensive equipment.

Description

Technical Field

[0001] This invention belongs to the field of chemistry and mainly includes a three-dimensional zinc metal-organic framework with fluorescence detection function and its synthesis and application methods; in particular, it relates to a zinc-based coordination polymer and a method for preparing a membrane and its application in fluorescence detection of cytisine. Background Technology

[0002] Cytisine (CTS), a partial agonist of acetylcholine receptors, has received widespread attention since its extraction in 1865 due to its unique effects. As a partial agonist of acetylcholine, CTS has shown significant therapeutic effects in smoking cessation and has been used to develop smoking cessation drugs such as Tabex and Desmoxan. Furthermore, because acetylcholine plays a role in regulating neurotransmitter release, neuronal integration, and cellular excitation in the central nervous system, CTS also shows great potential in treating neurological diseases such as Alzheimer's and Parkinson's, and has been extensively studied. However, excessive use of CTS can lead to serious toxic side effects, such as mental confusion, seizures, respiratory paralysis, and even circulatory failure. Therefore, effective detection of CTS concentration is of great significance for the treatment of neurological diseases and human health. However, CTS has weak absorption and emission capabilities, making low concentrations difficult to detect. Currently reported methods for CTS detection, including mass spectrometry, molecular imprinting, and capillary electrophoresis, are limited by expensive equipment or complex and cumbersome procedures, hindering their widespread application. Therefore, developing a convenient, effective, and rapid method for CTS detection is of significant practical importance.

[0003] Fluorescence spectroscopy offers significant advantages in the field of sensor detection due to its short reaction time, ease of operation, and high sensitivity, and has been extensively studied. Therefore, detecting cytotoxic substances (CTS) using fluorescence spectroscopy has broad application prospects. The key to fluorescence spectroscopy is the preparation of suitable materials with fluorescence emission capabilities that can specifically respond to the analyte with fluorescence. Currently, there is only one study using a protein fluorescent probe to monitor CTS based on fluorescence response; however, this probe suffers from cumbersome preparation methods, stringent environmental requirements, and susceptibility to degradation. Therefore, there is a need to develop novel materials that can conveniently, efficiently, and rapidly analyze and identify CTS using fluorescence spectroscopy.

[0004] In recent years, metal-organic frameworks (MOFs) have attracted widespread attention due to their unique characteristics, such as high porosity, large specific surface area, tunable multifunctional groups, adjustable pore size, and multi-center active sites. To date, MOF materials have been used for the detection of various substances, including cations and anions, pesticides, antibiotics, biomarkers, and explosives. However, no luminescent probes based on MOF materials have yet been developed for CTS detection. Summary of the Invention

[0005] To address the problems of existing technologies, namely the cumbersome nature and complex instrumentation of current CTS detection methods, a simple, rapid, and effective novel CTS detection method is needed. Based on this, this invention proposes a method for preparing a zinc-based coordination polymer film and for fluorescently detecting CTS. This material exhibits a specific fluorescent recognition response to CTS and possesses high sensitivity, interference resistance, and cyclicability.

[0006] The technical solution of the present invention is as follows:

[0007] A zinc-based coordination polymer; a three-dimensional zinc metal-organic framework material, the framework being composed of binuclear zinc and organic ligands linked together to form one-dimensional channels, with the chemical formula {NH2(CH3)2·[Zn(TDA)]·DMF·3C2H5OH} n It exhibits a fluorescence emission peak at 400 nm.

[0008] The zinc-based coordination polymer described above has a crystal space group of Fddd for the metal-organic framework material. Each binuclear zinc unit is linked to five independent ligands, which have two coordination modes. One ligand connects two binuclear zinc units via their two terminal carboxyl groups and then connects another binuclear zinc unit using the two adjacent nitrogen atoms at the triazole site. The other ligand connects two binuclear zinc units using only their two terminal carboxyl groups. Through these connection modes, the binuclear zinc units and the two ligands are linked to grow into a three-dimensional framework. This three-dimensional framework has a one-dimensional channel diameter along the c-axis of [missing information].

[0009] The present invention discloses a method for preparing a zinc-based coordination polymer, which involves reacting zinc iodide and 4,4'-(1H-1,2,4-triazol-3,5-diyl)dibenzoic acid in a mixed solvent of DMF and ethanol, with acetic acid added as a modifier, via a hydrothermal reaction.

[0010] The preparation method includes the following steps:

[0011] (1) Add zinc iodide and 4,4'-(1H-1,2,4-triazol-3,5-diyl)benzoic acid to a mixture of ethanol, acetic acid and N,N-dimethylformamide and stir until homogeneous. The molar ratio of zinc iodide, 4,4'-(1H-1,2,4-triazol-3,5-diyl)benzoic acid, glacial acetic acid, ethanol and N,N-dimethylformamide is (2-2.5):(1):(10-20):(300-400):(700-800);

[0012] (2) Place the mixture obtained in step (1) into a sealed container, put it into a reaction oven, heat it at 80-90℃, and continue heating for 48-72 hours to obtain a transparent block crystal product, which is a zinc metal-organic framework material with fluorescent recognition function.

[0013] The present invention discloses a zinc-based coordination polymer for detecting the antibiotic cytisine; comprising the following steps:

[0014] (1) The prepared zinc metal-organic framework material was ultrasonically dispersed in an aqueous solution. Different concentrations of cytisine were added to the solution, and the corresponding fluorescence spectra were tested. The recognition effect of the zinc metal-organic framework material with specific fluorescence recognition function on cytisine was obtained based on the fluorescence intensity change of the aqueous solution of the zinc metal-organic framework material under different concentrations of cytisine treatment.

[0015] (2) Add different amounts of cytisine aqueous solution to the aqueous solution of the zinc metal-organic framework material with fluorescence recognition function using a pipette and test its fluorescence intensity; fit the obtained data to obtain the quantitative relationship between the fluorescence intensity of the zinc metal-organic framework material with fluorescence recognition function and the detection limit of cytisine concentration in the aqueous solution.

[0016] The zinc-based coordination polymer of the present invention is applicable to the identification of cytisine in aqueous solutions of KCl, NaCl, K2SO4, Zn(NO3)2, Ga(NO3)3 or FeCl2.

[0017] A zinc-based coordination polymer of the present invention is suitable for identifying cytisine in other similar drugs containing aqueous solutions of cytisine, arecoline, arecoline hydrochloride, homovanillic acid, limonene, oxymatrine, and sophoridine.

[0018] The present invention discloses a method for synthesizing polymer membrane materials using zinc-based coordination polymers, comprising the following steps:

[0019] (1) Mix zinc metal-organic framework material, PVDF and DMF in a mass ratio of 1:10-30:200-300 and stir to form a homogeneous solution;

[0020] (2) Mix PVA with water at a mass ratio of 1:100-200, heat at 80°C for 30-60 minutes until the particles are completely dissolved to obtain a PVA aqueous solution;

[0021] (3) The PVA aqueous solution obtained in step (2) and the PVDF solution obtained in step (1) are mixed at a volume ratio of 1:1 to 1:3 and stirred evenly. Then, the mixture is placed in an oven at a temperature of 80-120℃ to heat and evaporate the solvent to obtain a white coordination polymer film material with fluorescent recognition ability.

[0022] A method for preparing polymer membrane materials from zinc-based coordination polymers for the detection of cytisine includes the following steps:

[0023] (1) Cut the membrane material into multiple regular squares with a size of 3×3mm, drop water solutions containing different concentrations of cytisine onto the membrane material, and then irradiate it with a 254nm ultraviolet lamp. Determine the concentration of cytisine based on the change in the fluorescence color emitted by the membrane material.

[0024] (2) Use the mobile phone software "Color Scan" to scan and analyze the fluorescence emitted by the membrane material treated with different concentrations of cytisine aqueous solution in step (1), and obtain the corresponding RGB values. Fit the obtained RGB values ​​with the corresponding cytisine concentration to obtain the quantitative relationship between the coordination polymer membrane with fluorescence recognition function and the detection of cytisine in aqueous solution.

[0025] This invention has the following advantages:

[0026] 1. The preparation process of zinc metal-organic framework materials with fluorescence recognition function is simple and convenient, and the reaction conditions are mild and environmentally friendly;

[0027] 2. High product yield and high purity;

[0028] 3. Zinc metal-organic framework materials with specific fluorescence recognition function can quickly and conveniently detect cytisine in aqueous solutions, with low detection limit, high sensitivity and recyclability.

[0029] 4. Membrane materials with fluorescence recognition capabilities are simple to prepare, portable to use, and do not rely on expensive equipment. Attached Figure Description

[0030] Figure 1 This is a synthesis reaction route diagram for the three-dimensional zinc metal-organic framework material with fluorescence detection function of the present invention;

[0031] Figure 2 This invention discloses a three-dimensional structure of a zinc metal-organic framework material with fluorescence recognition function;

[0032] Figure 3 This invention discloses a single-crystal data simulation and X-ray powder diffraction pattern of a zinc metal-organic framework material with fluorescence recognition function.

[0033] Figure 4 A is a fluorescence response diagram of a zinc metal-organic framework material with fluorescence recognition function disclosed in this invention to different concentrations of cytisine in aqueous solution.

[0034] Figure 4 B is a curve showing the fitting of a zinc metal-organic framework material with fluorescent recognition function to cytisine in aqueous solution, as disclosed in this invention.

[0035] Figure 5 This is a fluorescence response diagram of a zinc metal-organic framework material with fluorescence recognition function disclosed in this invention to cytisine in an aqueous solution containing interfering ions.

[0036] Figure 6 This is a response diagram of a zinc metal-organic framework material with fluorescence recognition function disclosed in this invention to different interfering antibiotics;

[0037] Figure 7 This invention discloses a method for preparing a coordination polymer film with fluorescence recognition function;

[0038] Figure 8 This invention discloses the fluorescence response relationship between the RGB values ​​of the membrane material fluorescence and the concentration of cytisine, wherein the RGB values ​​of the membrane material fluorescence are obtained by scanning and analysis using a mobile APP.

[0039] Figure 9 This is a linear relationship between the RGB values ​​of the fluorescence of the membrane material disclosed in this invention and the concentration of cytisine. Detailed implementation method:

[0040] The specific embodiments of the present invention will now be described in detail with reference to the accompanying drawings and specific examples.

[0041] Example 1

[0042] A three-dimensional indium metal-organic framework material with fluorescence detection function is generated by a solvothermal reaction in a mixed solvent of 4,4'-(1H-1,2,4-triazol-3,5-diyl)dibenzoic acid (H₂TDA) and zinc iodide, with acetic acid as a modifier. The reaction route is shown in the figure. Figure 1 As shown.

[0043] This invention discloses a zinc metal-organic framework material with fluorescent recognition function, the chemical formula of which is {NH2(CH3)2·[Zn(TDA)]·DMF·3C2H5OH}. n Its three-dimensional structure diagram is as follows Figure 2 As shown; where H2TDA is 4,4'-(1H-1,2,4-triazol-3,5-diyl)dibenzoic acid, the structural formula of H2TDA is as follows:

[0044] Furthermore, a zinc metal-organic framework material with fluorescence recognition function is a three-dimensional structure compound based on binuclear zinc building blocks, containing large one-dimensional channels.

[0045] Single-crystal structure analysis of this metal-organic framework material with specific fluorescence recognition function revealed that its structure consists of binuclear zinc nodes bridged by ligand TDA, forming a three-dimensional zinc metal-organic framework structure, such as... Figure 2 As shown: Analysis revealed that the space group of this crystal is Fddd, where each binuclear zinc unit is linked to five independent ligands. There are two coordination modes for the ligands. One ligand connects two binuclear zinc units via its two terminal carboxyl groups and then connects another binuclear zinc unit using the two adjacent nitrogen atoms at the triazole site. The other ligand connects two binuclear zinc units using only its two terminal carboxyl groups. Through these connection modes, the binuclear zinc units and these two types of ligands grow into a three-dimensional framework. This three-dimensional framework has a one-dimensional channel diameter along the c-axis of [diameter missing].

[0046] The X-ray powder diffraction pattern of the sample and the single-crystal simulation pattern are in excellent agreement. The XRD peak positions (synthesized) of the experimentally prepared Zn-TDA are consistent with the XRD peak positions (simulated) obtained through its crystal structure simulation, indicating that the synthesized material has high phase purity; as shown in the attached figure. Figure 3 As shown.

[0047] The present invention discloses a method for preparing an indium metal-organic framework material with fluorescence recognition function.

[0048] In Example 2, zinc iodide and 4,4'-(1H-1,2,4-triazol-3,5-diyl)benzoic acid were added to a mixture of ethanol, acetic acid, and N,N-dimethylformamide and stirred until homogeneous. The molar ratio of zinc iodide, 4,4'-(1H-1,2,4-triazol-3,5-diyl)benzoic acid, glacial acetic acid, ethanol, and N,N-dimethylformamide was (2):(1):(10):(300):(700). The resulting mixture was placed in a sealed container and placed in a reaction oven. The temperature was set at 80°C and the mixture was heated for 72 hours to obtain a transparent blocky crystalline product, which is a zinc metal-organic framework material with fluorescent recognition function.

[0049] In Example 3, zinc iodide and 4,4'-(1H-1,2,4-triazol-3,5-diyl)benzoic acid were added to a mixture of ethanol, acetic acid, and N,N-dimethylformamide and stirred until homogeneous. The molar ratio of zinc iodide, 4,4'-(1H-1,2,4-triazol-3,5-diyl)benzoic acid, glacial acetic acid, ethanol, and N,N-dimethylformamide was (2.2):(1):(15):(350):(750). The resulting mixture was placed in a sealed container and placed in a reaction oven at 85°C for 60 hours to obtain a transparent blocky crystalline product, which is a zinc metal-organic framework material with fluorescent recognition function.

[0050] In Example 4, zinc iodide and 4,4'-(1H-1,2,4-triazol-3,5-diyl)benzoic acid were added to a mixture of ethanol, acetic acid, and N,N-dimethylformamide and stirred until homogeneous. The molar ratio of zinc iodide, 4,4'-(1H-1,2,4-triazol-3,5-diyl)benzoic acid, glacial acetic acid, ethanol, and N,N-dimethylformamide was (2.5):(1):(20):(400):(800). The resulting mixture was placed in a sealed container and placed in a reaction oven at 85°C for 72 hours to obtain a transparent blocky crystalline product, which is a zinc metal-organic framework material with fluorescent recognition function.

[0051] In Example 5, zinc iodide and 4,4'-(1H-1,2,4-triazol-3,5-diyl)benzoic acid were added to a mixture of ethanol, acetic acid, and N,N-dimethylformamide and stirred until homogeneous. The molar ratio of zinc iodide, 4,4'-(1H-1,2,4-triazol-3,5-diyl)benzoic acid, glacial acetic acid, ethanol, and N,N-dimethylformamide was (2.1):(1):(10):(350):(800). The resulting mixture was placed in a sealed container and placed in a reaction oven at 90°C for 60 hours to obtain a transparent blocky crystalline product, which is a zinc metal-organic framework material with fluorescent recognition function.

[0052] In Example 6, zinc iodide and 4,4'-(1H-1,2,4-triazol-3,5-diyl)benzoic acid were added to a mixture of ethanol, acetic acid, and N,N-dimethylformamide and stirred until homogeneous. The molar ratio of zinc iodide, 4,4'-(1H-1,2,4-triazol-3,5-diyl)benzoic acid, glacial acetic acid, ethanol, and N,N-dimethylformamide was (2.4):(1):(15):(300):(750). The resulting mixture was placed in a sealed container and placed in a reaction oven at 90°C for 48 hours to obtain a transparent blocky crystalline product, which is a zinc metal-organic framework material with fluorescent recognition function.

[0053] The present invention relates to the application of zinc metal-organic framework materials with specific fluorescent recognition for the detection of cytisine.

[0054] Detection of cytisine in aqueous solution

[0055] First, 10 mg of a zinc-organic framework compound with fluorescent recognition function was weighed and dispersed in 30 mL of distilled water. Its fluorescence emission spectrum was measured, and an emission peak was found at 400 nm. Then, 3 mL of the dispersion of the zinc-organic framework compound was taken and its fluorescence intensity was measured. Subsequently, 50 μL of a 1 mg / mL cytisine solution was added to the aqueous solution of the zinc-organic framework compound, and its fluorescence emission spectrum was measured again.

[0056] The concentration of cytisine was varied, with the amount added gradually increasing from 0 to 350.6 μM using a pipette. The fluorescence intensity at 400 nm was measured, and it was found that the fluorescence intensity gradually decreased with increasing cytisine concentration. (See attached image.) Figure 4 As shown in Figure A, the quenching efficiency of cytisine can reach 90% when the concentration is 350.6 μM. Based on the 3σ criterion, the detection limit of this zinc-based metal-organic framework probe for cytisine is calculated to be as low as 5.26 × 10⁻⁶. -6 M indicates that the fluorescent probe has good sensitivity. The fluorescence intensity of the zinc-based metal-organic framework probe varies with the concentration of cytisine as follows: I0 / I = 0.9885 + 0.0091C. The relationship between I0 and I conforms to the Stern-Volmer (SV) equation, where Ksv is the quenching constant, C is the analyte concentration, I is the fluorescence intensity after the addition of cytisine, and I0 is the initial fluorescence intensity without the addition of cytisine. A good linear relationship is maintained in the range of 0-47.8 μM, with a correlation coefficient of 0.994, as shown in the attached figure. Figure 4 As shown in B, based on this linear relationship, the concentration of cytisine in the solution can be inferred from the change in fluorescence intensity of the zinc metal-organic framework compound.

[0057] In a zinc-organic framework (ZOM) compound with fluorescence recognition function, containing a concentration of 0.3 mg / mL, interference ion solutions of CaCl2, CO(NH2)2, KHCO3, MgCl2, KCl, NaCl, K2SO4, Zn(NO3)2, Ga(NO3)3, or FeCl2, with a quenching concentration equal to that of cytisine, were added. Each of these ion solutions was added separately to the dispersion of the ZOM compound, and the corresponding emission spectra were then measured to determine the effect of the interference ions on the fluorescence ability of the ZOM compound. Subsequently, an equal volume of cytisine was added to the aqueous solution of the ZOM compound, and its emission spectrum was measured as shown in the attached figure. Figure 5 As shown.

[0058] Antibiotics, including strychnine (ABS), arecoline (ACL), arecoline hydrochloride (ACH), homovanillic acid (HAA), limonene (MCT), oxymatrine (ATM), and sophoridine (SHD), were added in equal amounts to the quenching concentration of cytisine to zinc metal-organic framework compounds containing small amounts of these interfering antibiotic solutions. The solutions of these interfering antibiotics were then individually added to dispersions of the zinc metal-organic framework compounds, and their corresponding emission spectra were measured as shown in the attached figure. Figure 6 As shown, the effect of interfering antibiotics on the fluorescence ability of zinc metal-organic framework compounds was determined.

[0059] This invention prepares coordination polymer membrane materials with fluorescent recognition function based on zinc metal-organic frameworks:

[0060] Example 7:

[0061] Step 1): Grind 10 mg of zinc metal-organic framework material evenly, add it to 2 mL of DMF solution containing 100 mg PVDF, and disperse it by ultrasonication.

[0062] Step 2): Take another 10 mg of PVA and add it to 1 mL of water. Heat at 80°C for 30 minutes until the particles are completely dissolved to obtain a PVA solution.

[0063] Step 3): Mix the PVA aqueous solution obtained in step 2) and the PVDF solution obtained in step 1) at a volume ratio of 1:1, stir until homogeneous, and obtain a clear solution.

[0064] Example 8:

[0065] Step 1) Grind 20 mg of zinc metal-organic framework material evenly, add it to 6 mL of DMF solution containing 600 mg PVDF, and disperse it by ultrasonication.

[0066] Step 2) Take another 20 mg of PVA and add it to 4 mL of water. Heat at 80°C for 60 minutes until the particles are completely dissolved to obtain a PVA solution.

[0067] Step 3): Mix the PVA aqueous solution obtained in step 2) and the PVDF solution obtained in step 1) at a volume ratio of 1:2, stir until homogeneous, and obtain a clear solution.

[0068] Example 9:

[0069] Step 1) Grind 15 mg of zinc metal-organic framework material evenly, add it to 4 mL of DMF solution containing 300 mg PVDF, and disperse it by ultrasonication.

[0070] Step 2) Take another 20 mg of PVA and add it to 3 mL of water. Heat at 80°C for 45 minutes until the particles are completely dissolved to obtain a PVA solution.

[0071] Step 3): Mix the PVA aqueous solution obtained in step 2) and the PVDF solution obtained in step 1) at a volume ratio of 1:3, stir until homogeneous, and obtain a clear solution.

[0072] Example 10:

[0073] Step 1) Grind 10 mg of zinc metal-organic framework material evenly, add it to 1 mL of DMF solution containing 200 mg PVDF, and disperse it by ultrasonication.

[0074] Step 2) Add 10 mg of PVA to 1 mL of water and heat at 80°C for 45 minutes until the particles are completely dissolved to obtain a PVA solution. Step 3)

[0075] The PVA aqueous solution obtained in step 2) and the PVDF solution obtained in step 1) are mixed at a volume ratio of 1:1 and stirred until homogeneous to obtain a clear solution.

[0076] Example 11:

[0077] Step 1) Grind 15 mg of zinc metal-organic framework material evenly, add it to 3 mL of DMF solution containing 200 mg PVDF, and disperse it by ultrasonication.

[0078] Step 2) Take another 15 mg of PVA and add it to 2 mL of water. Heat at 80°C for 30 minutes until the particles are completely dissolved to obtain a PVA solution.

[0079] Step 3): Mix the PVA aqueous solution obtained in step 2) and the PVDF solution obtained in step 1) at a volume ratio of 1:2, stir until homogeneous, and obtain a clear solution.

[0080] Example 12:

[0081] Step 1) Grind 20 mg of zinc metal-organic framework material evenly, add it to 4 mL of DMF solution containing 400 mg PVDF, and disperse it by ultrasonication.

[0082] Step 2) Take another 20 mg of PVA and add it to 2 mL of water. Heat at 80°C for 60 minutes until the particles are completely dissolved to obtain a PVA solution.

[0083] Step 3): Mix the PVA aqueous solution obtained in step 2) and the PVDF solution obtained in step 1) at a volume ratio of 1:3, stir until homogeneous, and obtain a clear solution.

[0084] Example 13: The clear liquid obtained in Example 7, Example 8, Example 9, Example 10, Example 11, or Example 12 was placed in an 80°C oven to evaporate the solvent, yielding a white film material, which is the coordination polymer film material with fluorescent recognition capability, as shown in the attached figure. Figure 7 As shown.

[0085] Example 14: The clear liquid obtained in Example 7, Example 8, Example 9, Example 10, Example 11, or Example 12 was placed in a 100°C oven to evaporate the solvent, yielding a white film material, which is the coordination polymer film material with fluorescent recognition capability, as shown in the attached figure. Figure 7 As shown.

[0086] Example 15: The clear liquid obtained in Example 7, Example 8, Example 9, Example 10, Example 11, or Example 12 was placed in an oven at 120°C to evaporate the solvent, yielding a white film material, which is the coordination polymer film material with fluorescent recognition capability, as shown in the attached figure. Figure 7 As shown.

[0087] Specific implementation steps for the detection of cytisine in aqueous solution using coordination polymer membrane materials with fluorescent recognition capabilities:

[0088] (1) Cut the membrane material into multiple regular squares, and drop cytisine aqueous solution with a concentration of (0–52.6 mM) onto each of the cut membrane materials. Each concentration is a group. Then irradiate with a 254 nm ultraviolet lamp. As the concentration of cytisine increases, the fluorescence intensity of the membrane material treated with the corresponding cytisine aqueous solution gradually weakens, and the fluorescence color gradually changes from yellow to blue and finally to close to black.

[0089] (2) The fluorescence emitted by the membrane material treated with different concentrations of cytisine aqueous solution in (1) was scanned and analyzed using the mobile phone software "Color Scan". The corresponding RGB values ​​can be obtained as follows: Figure 8 As shown, the ratio of G to B values ​​was further calculated to obtain G / B. As the concentration of cytisine increased from 0 to 52.6 mM, the corresponding G / B value of the fluorescence displayed by the cytisine-treated membrane material gradually decreased from 5.44 to 0.29. Furthermore, the concentration of cytisine and the G / B value of the membrane conformed to a quantitative relationship between 0 and 52.6 mM: y = exp(1.1560 - 0.1289x + 0.0016x). 2 When the concentration of cytisine is in the range of 5.26-26.3 mM, it follows a linear relationship: y = 1.6192 - 0.0492x. Figure 9 As shown. Based on this quantitative relationship, the concentration of cytisine in the aqueous solution can be calculated, where y is the G / B value and x is the MNZ concentration.

[0090] This invention prepares a zinc metal-organic framework material (ZMOR) for convenient, efficient, and rapid detection of cytisine via fluorescence recognition. Furthermore, this ZMOR material is fabricated into a membrane material capable of fluorescence recognition of cytisine. This membrane material exhibits fluorescence intensity and color changes in response to different concentrations of cytisine. These color changes can be scanned using a mobile app to obtain the RGB values, allowing for convenient estimation of the CTS concentration in the analyte by scanning the membrane's color. This invention effectively alleviates the problems of cumbersome procedures and the need for expensive equipment in current methods for detecting cytisine.

[0091] The technical solutions disclosed and proposed in this invention can be implemented by those skilled in the art by appropriately modifying the conditions and routes, etc. Although the methods and preparation techniques of this invention have been described through preferred embodiments, those skilled in the art can obviously modify or recombine the methods and technical routes described herein without departing from the content, spirit, and scope of this invention to achieve the final preparation technique. It should be particularly noted that all similar substitutions and modifications are obvious to those skilled in the art and are considered to be included within the spirit, scope, and content of this invention.

Claims

1. A zinc-based coordination polymer, characterized in that, This is a three-dimensional zinc metal-organic framework material, consisting of binuclear zinc and organic ligands linked together, possessing one-dimensional channels, and with the chemical formula {NH2(CH3)2·[Zn(TDA)]·DMF·3C2H5OH}. n It exhibits a fluorescence emission peak at 400 nm; the space group of the metal-organic framework material is Fddd; each binuclear zinc unit is linked to five independent ligands, which have two coordination modes. One ligand links two binuclear zinc units through the two terminal carboxyl groups and then links another binuclear zinc unit using the two adjacent nitrogen atoms in the triazole site; the other ligand links two binuclear zinc units using only the two terminal carboxyl groups. Through these connection modes, the binuclear zinc units and the two ligands are linked to grow into a three-dimensional framework; the one-dimensional channel diameter along the c-axis of this three-dimensional framework is 13.5 × 10.6 Å; where: TDA is 4,4'-(1H-1,2,4-triazol-3,5-diyl)dibenzoic acid; DMF is N,N-dimethylformamide; NH2(CH3)2 is a dimethylamine cation generated in situ during the synthesis of DMF.

2. The method for preparing a zinc-based coordination polymer according to claim 1, characterized in that, It is prepared by hydrothermal reaction of zinc iodide and 4,4'-(1H-1,2,4-triazol-3,5-diyl)dibenzoic acid in a mixed solvent of DMF and ethanol, with acetic acid as a modifier.

3. The preparation method according to claim 2, characterized in that, Includes the following steps: (1) Add zinc iodide and 4,4'-(1H-1,2,4-triazol-3,5-diyl)dibenzoic acid to a mixture of ethanol, acetic acid and N,N-dimethylformamide and stir until homogeneous. The molar ratio of zinc iodide, 4,4'-(1H-1,2,4-triazol-3,5-diyl)dibenzoic acid, acetic acid, ethanol and N,N-dimethylformamide is (2-2.5):(1):(10-20):(300-400):(700-800). (2) Place the mixture obtained in step (1) in a sealed container, put it in a reaction oven, heat it at 80-90℃, and continue heating for 48-72 hours to obtain a transparent blocky crystal product, zinc metal-organic framework material.

4. The application of the zinc-based coordination polymer according to claim 1 in the detection of the antibiotic cytisine, characterized in that, Includes the following steps: (1) The prepared zinc metal-organic framework material was ultrasonically dispersed in an aqueous solution. Different concentrations of cytisine were added to the solution, and the corresponding fluorescence spectra were tested. The recognition effect of zinc metal-organic framework material with specific fluorescence recognition function on cytisine was obtained based on the fluorescence intensity change of the aqueous solution of zinc metal-organic framework material under different concentrations of cytisine treatment. (2) Add different amounts of cytisine aqueous solution to the aqueous solution of the zinc metal-organic framework material with fluorescence recognition function using a pipette and test its fluorescence intensity; fit the obtained data to obtain the quantitative relationship and detection limit of the fluorescence intensity of the zinc metal-organic framework material with fluorescence recognition function to the detection of cytisine concentration in aqueous solution.

5. The application of the zinc-based coordination polymer as described in claim 4 for the detection of the antibiotic cytisine, characterized in that, It is applicable to the identification of cytisine in aqueous solutions containing CaCl2, CO(NH2)2, KHCO3, MgCl2, KCl, NaCl, K2SO4, Zn(NO3)2, Ga(NO3)3 or FeCl2.

6. The application of the zinc-based coordination polymer as described in claim 4 for the detection of the antibiotic cytisine, characterized in that, It is applicable to the identification of cytisine in aqueous solutions containing cytisine, arecoline, arecoline hydrochloride, homovanillic acid, lily alkaloid, oxymatrine, and sophoridine.

7. The method for synthesizing polymer membrane materials using zinc-based coordination polymers as described in claim 1, characterized in that, Includes the following steps: (1) Mix zinc metal-organic framework material, PVDF and DMF in a mass ratio of 1:10-30:200-300 and stir until homogeneous to obtain a mixed solution; (2) Mix PVA with water at a mass ratio of 1:100-200, heat at 80 ℃ for 30-60 minutes until the particles are completely dissolved to obtain a PVA aqueous solution; (3) The PVA aqueous solution obtained in step (2) and the PVDF solution obtained in step (1) are mixed at a volume ratio of 1:1~3, stirred evenly, and then placed in an oven at a temperature of 80-120℃ to heat and evaporate the solvent to obtain a white coordination polymer film material with fluorescent recognition ability.

8. A method for detecting cytisine using the polymer membrane material prepared by the method of claim 7, comprising the following steps: (1) Cut the membrane material into multiple regular squares with a size of 3×3 mm, drop aqueous solutions of cytisine with different concentrations onto the membrane material, and then irradiate it with a 254 nm ultraviolet lamp. Determine the concentration of cytisine based on the change in the fluorescence color emitted by the membrane material. (2) Collect the fluorescence emitted by the membrane material treated with different concentrations of cytisine aqueous solution in step (1) and obtain the corresponding RGB values. Fit the obtained RGB values ​​with the corresponding cytisine concentration to obtain the quantitative relationship between the coordination polymer membrane with fluorescence recognition function and the detection of cytisine in aqueous solution.

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