CN113121835A

CN113121835A - Iron-based metal organic framework material and preparation and application thereof

Info

Publication number: CN113121835A
Application number: CN201911419777.0A
Authority: CN
Inventors: 张翠玲; 鲜跃仲; 侯冬艳
Original assignee: East China Normal University
Current assignee: East China Normal University
Priority date: 2019-12-31
Filing date: 2019-12-31
Publication date: 2021-07-16
Anticipated expiration: 2039-12-31
Also published as: CN113121835B

Abstract

The invention belongs to the field of environmental monitoring, and discloses an iron-based metal organic framework material Fe-MOFs and a synthesis method thereof, wherein 3, 5-dicarboxyphenylboronic acid is used as a ligand to be assembled with metal iron ions, and the assembly is reacted under the action of a regulator to obtain the boric acid functionalized iron-based metal organic framework material (Fe-MOFs). Research results show that the Fe-MOFs nano material shows excellent peroxide mimic enzyme properties. Fe-MOFs are capable of catalyzing the oxidation of colorless 3,3',5,5' -Tetramethylbenzidine (TMB) in the presence of hydrogen peroxide to a blue color. Meanwhile, when fluoride ions exist in the system, the peroxidase property of Fe-MOFs is inhibited based on the specific recognition of the fluoride ions by boric acid and the strong interaction between metal ions and the fluoride ions. Based on the method, the invention constructs a new method for colorimetric detection of the fluoride ions. The method has high selectivity and sensitivity for detecting the fluorine ions, and has great application potential for the visual detection of the fluorine ions in environmental monitoring.

Description

Iron-based metal organic framework material and preparation and application thereof

Technical Field

The invention belongs to the field of environmental monitoring, relates to preparation and application of an iron-based metal organic framework material, and particularly relates to a composite material prepared from 3,5 and a metal oxide^-Dicarboxylic phenyl boronic acids as ligands with Fe³⁺Assembling and preparing novel iron-based metal organic framework material (Fe-M) with peroxide mimic enzyme propertyOFs) and its use in environmental water samples F^-Detection of (3).

Background

Fluoride ion is a trace element necessary for the human body, and has a very large effect on organisms. It plays an important role in the formation and metabolism of teeth and bones in the physiological functions of human body. The fluorine-containing organic fertilizer is widely distributed in earth surfaces, coal, water bodies and ores, and if the fluorine content in the coal and the ores is too high, the fluorine-containing organic fertilizer can have adverse effects on the health life of human beings. For example, in coal combustion processes, silicon tetrafluoride is discharged to the environment and enters the water source via rainwater, resulting in excessive levels of elemental fluorine in the water. World Health Organization (WHO) advises drinking water F^-Should be 1.5ppm, excessive fluoride intake may lead to fluorosis, urolithiasis and many serious neurodegenerative diseases. Therefore, for F in natural environment^-The quantitative detection of the method has important significance.

At present F^-Conventional analytical techniques for detection include potentiometry, chromatography, spectrometry, and the like based on ion-selective electrodes. Among these analytical methods, the ion selective electrode method detects F in a sample^-The content is easy to operate, but the level of trace analysis is difficult to accurately and precisely reach for special samples, and the content is influenced by detection environment, electrode materials, interfering ions and pH. Chromatography instruments are expensive, have high requirements on samples, and samples must be clear and free of impurities and cannot be monitored online. Spectrometry is a powerful tool because of its simplicity, low cost, simplicity of operation, and fast response time. Particularly, the nano material with unique optical characteristics is F due to its simplicity, high cost effectiveness and high speed^-Sensing provides convenience. In recent years, many nanomaterials including gold nanomaterials, quantum dots, Metal Organic Frameworks (MOFs), upconversion nanoparticles, etc. have designed a wide variety of nanosensors for the detection of F due to their ease of fabrication, low cost, high sensitivity and good biocompatibility^-. Therefore, the reliable, fast, easy-to-operate, real-time and visual detection of F in water samples is developed^-Especially for countries with limited resources and remote areasIt is necessary. In view of this, new nanoprobes were developed for high-sensitivity detection of visualization F^-Has important significance.

The nano enzyme is a nano material with enzyme-like characteristics, but is superior to natural enzyme, and is generally low in cost, stable and suitable for mass production. In addition, the unique physical and chemical properties of the nano material not only endow the nano enzyme with multiple functions, but also provide more possibilities for reasonable design and future application. In recent years, many MOFs nanomaterials with porous nature and high specific surface area have been found to have enzyme mimetic properties. The MOFs material with peroxidase property can be easily assembled by using copper, nickel, manganese, cobalt and iron metal clusters and ligands such as phthalic acid, benzenetricarboxylic acid and phenyl porphin, and can be widely applied to the fields of pharmacy, biotechnology, environment and the like. However, the defects in the art are that the types of the currently reported nanoenzymes are far from enough, and the catalytic performance of part of materials is low and is not easily modified. Therefore, much effort is still required to explore or develop more nanoenzymes having higher enzymatic activities.

Disclosure of Invention

The invention takes 3, 5-dicarboxyphenylboronic acid (5-bop) as a ligand and Fe for the first time³⁺Assembling, namely successfully preparing a novel iron-based metal organic framework material Fe-MOFs with peroxide simulation enzyme property in an oil bath pot by a simple solvothermal method, and using the Fe-MOFs in an environmental water sample F^-Detection of (3).

The invention aims to prepare a novel Fe-MOFs (iron-based metal organic frameworks) with peroxide mimic enzyme property and construct colorimetric detection F^-The novel process of (1). The method has high selectivity and sensitivity, and can be used for F in environmental monitoring^-The detection of (2) has great application potential.

In order to achieve the purpose, the technical scheme adopted by the invention is as follows:

the invention provides a method for synthesizing Fe-MOFs (Fe-Metal organic frameworks) as an iron-based metal organic framework material, which uses a DMF (dimethyl formamide) solvent in an oil bath pan and uses Fe³⁺Being a metal centre, 3,5^-Dicarboxyphenyl boric acid as ligand, reacting under the action of regulatorAnd obtaining the iron-based metal organic framework material.

Wherein said Fe is contained³⁺The compound of (A) can be one or more of ferric trichloride hexahydrate, ferric nitrate nonahydrate and the like; preferably, ferric chloride hexahydrate.

Wherein the regulator is acetic acid.

Wherein the reaction vessel is one or more of an oil bath kettle, a tetrafluoroethylene reaction kettle and the like; preferably an oil bath pan. The product synthesized in the tetrafluoroethylene reaction kettle has no peroxidase property.

Wherein the molar ratio of the metal center to the ligand to the regulator is 1:1:5, 1:2:10, 2:1:10, 1:1: 10; preferably, it is 1:1: 10. Only in this ratio, MOF structure was formed, and the products synthesized in other ratios were amorphous powders.

Wherein the reaction temperature is 90 ℃ and 120 ℃; preferably, it is 120 ℃. Amorphous powder formed at 90 ℃.

Wherein the reaction time is 4 hours, 8 hours, 12 hours or more; preferably, it is 12 hours. No solid is generated in a period of time before the reaction, solid is gradually generated along with the reaction, and rod-shaped structures of the MOF are more and more, so that the MOF does not have particularly obvious change after a certain period of time.

In one embodiment, the synthesis method of the iron-based metal organic framework material Fe-MOFs is as follows: 0.1446 g of 3,5 are weighed firstly^-Dicarboxyphenylboronic acid and 0.187 g of ferric chloride hexahydrate were dissolved in 15ml of dmf, then acetic acid was added to the mixed solution for adjustment, and finally the mixed solution was placed in an oil bath pan and reacted at 120 ℃ for 12 hours. After the reaction was completed, the reaction mixture was cooled to room temperature, and the obtained precipitate was repeatedly washed with DMF and ethanol by centrifugation three times. And putting the obtained solid in a vacuum drying oven, and carrying out vacuum drying for one day at the temperature of 60 ℃ to obtain Fe-MOFs solid powder.

The invention also provides the iron-based metal organic framework material Fe-MOFs prepared by the method.

The iron-based metal organic framework material is good in crystallinity, rod-shaped and about 200nm in particle size.

Wherein the Fe-MOFs is a novel boric acid functionalized metal organic framework material.

Wherein the Fe-MOFs is an iron-based metal organic framework material Fe-MOFs with peroxide mimic enzyme property.

Compared with similar materials with peroxide mimic enzyme properties, the Fe-MOFs prepared by the method has relatively high catalytic activity.

The invention also provides a method for detecting F in the Fe-MOFs of the iron-based metal organic framework material^-The use of (1).

The specific mechanism is as follows: due to the ligand (3, 5)^-Dicarboxyphenylboronic acid) can specifically recognize F^-And is Fe³⁺And F^-Has strong binding capacity, and the synergistic effect of the two can ensure that the Fe-MOFs can realize F pair^-And (4) sensitive detection.

The specific experiment is as follows: first, separately adding (a) H to an aqueous solution₂O₂+TMB、(b)H₂O₂+ TMB + Fe-MOFs and (c) H₂O₂+TMB+Fe-MOFs+F^-Observing the absorbance change of different reaction systems at 652nm, and verifying that Fe-MOFs has peroxidation mimic enzyme property and F^-Inhibiting enzyme properties, and then altering F^-Amount of (2), observing UV absorption intensity with addition of F^-Trend of concentration. In addition, the present invention selects some common anions (Cl)^-、Br^-、I^-、SO₄ ^2-、NO₃ ^-、HCO₃ ^-Etc.) to perform a selectivity experiment.

The invention innovatively provides that the Fe-MOFs of the iron-based metal organic framework material is used for detecting F for the first time^-The use of (1). Provides the specific recognition function of the 3, 5-dicarboxyphenyl boric acid on the fluorinion and the property of the peroxide mimic enzyme, can realize the requirement of visual detection, and adds Fe³⁺Has strong coordination capacity with fluorinion, so the invention firstly recognizes the ligand which has specificity to fluorinion and Fe³⁺Assembling to prepare the MOF nano materialMore sensitive detection and visual detection of fluoride ions.

The invention also provides a portable kit, which comprises Fe-MOFs, TMB and agarose.

The invention also provides a portable kit for detecting F^-The use of (1).

The portable kit is combined with a smart phone in detection F^-Then, F can be paired^-The method is simple, quick and visual. The experiment is as follows: 15mg of agarose was weighed and dissolved in 3.9mL of ultrapure water and heated to boiling. When the solution was cooled to 50 deg.C, 100. mu. LFe-MOFs (0.1mg/mL) and 1mM TMB solution (10mM) were added, and 150. mu.L of the mixed solution was poured into a microcentrifuge tube cap after uniform mixing. Drying at room temperature for 5min, and molding. Then adding F with different concentrations into the portable kit^-After the concentration, the centrifugal tube is closed and the reverse is turned off to ensure that the solution and the hydrogel fully react for 60min, and then 200 mu LH is added₂O₂After incubation of the solution (1mM) at 37 ℃ for 15min, the lid was removed and a photograph taken using iPhone7 with the camera at a distance of 15 cm from it. The color information (RGB values) was then read using image analysis software, and the R/G values were observed as F was added^-Trend of concentration.

Wherein, the mass fraction of the agarose in the kit is 0.2-1.0%; preferably, 0.2%, 0.3%, 0.5%, 0.8%, 1.0%; further preferably, it is 0.3%. When the content of the agarose is less than 0.3%, the hydrogel formed in the kit is not stable enough and is easy to fall off; and when the content of the agarose is higher than 0.3%, the hydrogel in the formed kit is too solidified, so that fluorine ions are not favorably introduced into the hydrogel to damage Fe-MOFs materials, and the color development of the kit is not sensitive to the concentration change of the fluorine ions.

Wherein the content of Fe-MOFs in the kit is 1-10 mug/mL; preferably 1. mu.g/mL, 2. mu.g/mL, 4. mu.g/mL, 7. mu.g/mL, 10. mu.g/mL; more preferably, it is 2. mu.g/mL. When the content of Fe-MOFs is too low, the final color development of the kit is too shallow, and when the content of Fe-MOFs is too high, a large amount of fluorine ions are needed to destroy the structure of the kit, so that the detection of the fluorine ions is not sensitive enough.

Wherein, the reaction time of the fluorinion and the hydrogel is 5-120 min; preferably, 5min, 15min, 30min, 60min, 120 min; further preferably, it is 60 min. Fluoride ions need time to enter the hydrogel to react with Fe-MOF to destroy the skeleton structure, and experiments prove that the reaction can be completely realized within 60 min.

The invention has the beneficial effects that: by selecting new ligands with Fe³⁺Assembling, successfully preparing a new Fe-MOFs with peroxide mimic enzyme property, and preparing the material into a portable kit for F in an environmental water sample^-Visual detection of (2). Experiments prove that the method is used for F^-The linear range of visual detection of (2) is between 10.0 and 200. mu.M, and the detection limit is about 1.5. mu.M. Experiments prove that the method can realize rapid, easy-to-operate, real-time and visual detection of F in the water sample^-And is superior to the existing detection methods.

Drawings

FIG. 1 shows the synthesis and detection of Fe-MOFs^-Schematic diagram of principle: of these, 3, 5-dicarboxyphenylboronic acid and Fe³⁺Fe-MOFs is generated through reaction, after F-is added, the framework of the MOF collapses, and the peroxidase activity is inhibited.

FIG. 2 is a powder X-ray diffraction diagram of the product obtained by reacting the molar ratios of different metal centers, ligands and modifiers for 12 hours: wherein, the ratio of the graph (A) to the graph (B) is 1:2: 10; FIG. (B) is 2:1: 10; FIG. (C) is 1:1: 5; FIG. D shows 1:1: 10.

FIG. 3 is a TEM image of the synthesized product with different molar ratios of metal center, ligand, and modifier: wherein, the ratio of the graph (A) to the graph (B) is 1:2: 10; FIG. (B) is 2:1: 10; FIG. (C) is 1:1: 5; FIG. D shows 1:1: 10.

FIG. 4 is a UV-vis spectrum of ligands and Fe-MOFs in aqueous solution.

FIG. 5 is an FTIR spectrum of ligands and Fe-MOFs.

FIG. 6 is a graph of absorbance versus time at 652nm for different reaction systems: wherein, the diagram (a) is TMB + Fe-MOFs; FIG. B is H₂O₂+ TMB; FIG. C is H₂O₂+TMB+Fe-MOFs。

FIG. 7 shows the kinetics and catalysis of the enzymatic reaction processPhysical research picture: (A) retention of H₂O₂TMB concentration was varied at a concentration of about 1.0 mM; (B) maintaining TMB concentration at about 0.6mM changes H₂O₂Concentration; (C) and (D) are plots of the reciprocal numbers of the Fe-MOFs obtained from (A) and (B).

FIG. 8 shows Fe-MOFs and F^-TEM images of pre-reaction (A) and post-reaction (B).

FIG. 9 is F^-A feasibility test of detection; wherein (a) H₂O₂+TMB；(b)H₂O₂+TMB+Fe-MOF；(c)H₂O₂+TMB+Fe-MOF+F^-(30μM)。

FIG. 10 is F^-Selective response experiments; wherein, 1.F^-2.Br^-3.I^-4.Cl^-5.CO₃ ^2-6.HCO₃ ^-7.NO₃ ^-8.SO₄ ^2-9.BrO₃ ^-10.Ac^-11.Al³⁺12.Ca²⁺13.Cu²⁺14.K⁺15.Mg²⁺16.Zn²⁺。

FIG. 11 is F^-The detection experiment of (2): wherein (A) different concentrations of F^-(0, 1. mu.M, 2. mu.M, 4. mu.M, 8. mu.M, 10. mu.M, 20. mu.M, 30. mu.M, 40. mu.M, 50. mu.M, 80. mu.M, 100. mu.M, 200. mu.M) inhibitory effect on peroxidase properties of Fe-MOFs; (B) UV absorption intensity with addition of F^-Trend of concentration. Wherein F^-Has a linear detection range of 2.0^-30 μ M with the linear equation y ═ 0.894-0.0149x, R²＝0.998。

Fig. 12 is a smartphone imaging based visual detection: wherein (A) is a kit with the addition of F^-A color variation trend graph of concentration; (B) the method comprises the steps of obtaining a sensing platform picture based on a smart phone image; (C) R/G value in kit color is dependent on F^-And (3) a trend graph of concentration change. Wherein, with F^-Changes in concentration (0, 10. mu.M, 20. mu.M, 30. mu.M, 50. mu.M, 100. mu.M, 200. mu.M) the R/G values of the kit colors were 0.37421, 0.40229, 0.43931, 0.45729, 0.49741, 0.6424, 0.82862, respectively. Wherein F^-Has a linear detection range of 10.0^-200 μ M with the linear equation y ═ 0.3937+0.0022x, R²＝0.992。

Detailed Description

The features and advantages of the present invention will be further understood from the following detailed description taken in conjunction with the accompanying drawings. The examples provided are merely illustrative of the method of the present invention and do not limit the remainder of the disclosure in any way.

Example 1

Preparation of Fe-MOFs: based on the research on the Fe-MOFs synthetic method and the nanoenzyme functionalization in some documents, a certain amount of 3,5 is firstly weighed by a simple solvothermal method^-Dicarboxyphenylboronic acid and ferric trichloride hexahydrate are dissolved in 15ml DMF, then acetic acid is respectively added into the mixed solution for regulation, finally the mixed solution is placed in an oil bath kettle for reaction for 12 hours at 120 ℃, and the specific dosage of the products obtained by monitoring the reaction time is shown in Table 1. After the reaction is finished, the reaction product is cooled to room temperature, and the product is collected after centrifugation and repeatedly centrifuged and washed with DMF and ethanol for three times. And putting the obtained solid in a vacuum drying oven, and carrying out vacuum drying for one day at the temperature of 60 ℃ to obtain Fe-MOFs solid powder.

As shown in fig. 2 and 3, in the synthesis process, the invention finds that the adjustment of the acid-base property of the solvent has a great influence on the shape and size of the MOFs, and the addition of acetic acid makes the crystallization rate reduced to form a regular structure more easily. Thus, in order to obtain MOFs with regular and uniform shapes, the molar ratio of metal center, ligand and modifier is finally chosen to be 1:1:10, i.e. 0.1446 g (0.692mmol)3,5^-Dicarboxyphenylboronic acid and 0.187 g (0.692mmol) of ferric chloride hexahydrate were added during the synthesis, and 6.92mmol of acetic acid was added to the mixture to react in an oil bath at 120 ℃ for 12 hours to obtain Fe-MOFs having good crystallinity and rod-like particle size of about 200nm (FIGS. 2D and 3D).

In addition, by ultraviolet radiation^-Visible spectrophotometer for ligand 5^-bop and Fe-MOFs, it can be seen from FIG. 4 that the ligands have characteristic absorption peaks due to pi-pi transition on the ligands. Fe-MOFs have no characteristic peak, probably because of 3,5^-Dicarboxyphenylboronic acid and Fe³⁺A conjugated system is formed. Followed by Fourier transform Infrared Spectroscopy (FT)^-IR) to ligand 5^-bop and Fe-MOFs, as shown in FIG. 5, ligand 5^-bop at 1713cm^-1The shoulder at (A) was ascribed to C ═ O stretching vibration, while the peak was not observed in the pattern of Fe-MOFs, indicating that the carboxyl group and Fe³⁺The coordination successfully forms Fe-MOFs. In addition, in 5^-bop and Fe^-1383cm caused by B-O stretching vibration appears on two spectra of the MOF^-1And 1314cm^-1Shoulder peak of (C), thereby further proving Fe^-Successful preparation of MOFs materials.

TABLE 1 influence of the molar ratios of metal center, ligand, modifier and reaction time on the product during the synthesis

Example 2

Study of the Properties of Fe-MOFs peroxidases: the invention adopts the simple and classical reaction of hydrogen peroxide and peroxidase for oxidizing TMB and inspects the peroxidase activity of Fe-MOFs. As shown in FIG. 6, when Fe-MOFs were not added to the system, the oxidation efficiency of TMB by hydrogen peroxide was very low (FIG. 6 (b)); in the presence of Fe-MOFs, TMB was rapidly oxidized to blue by hydrogen peroxide and exhibited a distinct characteristic absorption peak at 652nm for oxidized TMB (oxTMB) (see FIG. 6 (c)). The results of this experiment successfully determined the simulated peroxidase activity of Fe-MOFs.

In addition, to further investigate the catalytic activity and kinetic parameters of Fe-MOFs, TMB and H were added₂O₂Related experiments were performed using as substrate for the determination of apparent steady state kinetics. Kinetic data were obtained by fixing the concentration of one substrate and varying the other. FIGS. 7C and D show that H was changed when TMB substrate concentration was fixed₂O₂Concentration, or fixation of H₂O₂When the concentration of the TMB substrate is changed, the three reciprocal curves are approximately parallel, which proves that the catalysis of the Fe-MOFs conforms to the ping-pong mechanism. At the same time, use Lineweaver^-Burk to calculate the Michaelis constant (Km) and maximum initial velocity (Vm) of Fe-MOFs^-Menten powerThe mathematical equation can be expressed as v ═ (vmax × [ S ]])/(Km+[S]) Vmax and Km values can be calculated. Vmax represents the reaction rate when the enzyme is saturated with the substrate, Km is called the Michaelis constant, and the lower the value of Km, the stronger the affinity between the Km and the substrate, the better the catalytic effect. The present invention compares it with native HRP horseradish peroxidase (table 2). The results show that the test strip can be used for both TMB and H₂O₂The Km of Fe-MOFs is lower than that of horseradish peroxidase, and a better catalytic effect is shown.

TABLE 2 comparison of kinetic parameters of Fe-MOF and HRP

Example 3

Fe-MOFs for detecting F^-The experiment of (2): at H₂O₂In the presence of the catalyst, Fe-MOFs is added into a TMB system, and the color is obviously changed, so that the TMB is catalyzed and oxidized. When F is added to the system^-When, Fe-MOFs and F^-Specific recognition and Fe³⁺And F^-Leads to collapse of the framework (FIGS. 8A and B), which in turn leads to catalysis H₂O₂The ability to oxidize TMB is diminished. Thus, the oxidation process of TMB is effectively inhibited, the system color becomes light blue, and the absorbance is reduced, namely F^-Has great inhibition effect on the mimic enzyme activity of Fe-MOFs (as shown in figure 9). In view of this, the present invention develops a method for detecting F^-Colorimetric sensing of (1). Since biological samples of complex composition are often faced in practical analytical applications, the selectivity of the assessment method is crucial. Thus, some common anions (Cl) were selected^-、Br^-、I^-、SO₄ ^2-、NO₃ ^-、HCO₃ ^-Etc.) to perform a selectivity experiment. As shown in fig. 10, except that F^-The method has great inhibition effect on the activity of mimic enzyme of Fe-MOFs, and common anions in an environmental water sample can not have great influence on the property of mimic peroxidase of Fe-MOFs. Based on the phenomenon, the invention realizes the direct detection of F by a colorimetric method^-. FromFIGS. 11A and B show that this method is for F^-Has a linear detection range of 2.0^-Between 30. mu.M, the limit of detection is about 1.0. mu.M.

Example 4

F^-The visual detection experiment of (2): the invention combines the image sensing of the smart phone with the F^-The inhibition of the peroxidase activity of Fe-MOFs was combined (FIG. 12A), and F was added to the newly synthesized Fe-MOFs and TMB kit at different concentrations^-The solution destroys the structure of Fe-MOFs, then adds H with the same quantity₂O₂An oxidative TMB process is performed. Due to different concentrations of F^-The Fe-MOFs in the kit are damaged to different degrees, so that the catalytic capability of the kit is different, and finally the color of hydrogel on a cover of the kit is changed. The present invention obtains RGB values of the color of each kit by image software analysis using a photograph taken (fig. 12B). The R/G values and F can be found by data analysis^-The concentration has good linear relation to F^-The detection linear range of (1) is between 10 and 200 mu M, the detection limit is about 1.5 mu M and is far lower than F in drinking water allowed by WHO^-Is measured. In view of the above, the invention realizes the rapid, easy-to-operate, real-time and visual detection of F in the water sample^-。

Example 5

F^-The actual sample detection of (2): in order to evaluate the application of the Fe-MOFs (Table 1, reaction number 12) described in the present invention to the actual samples, F^-Feasibility of detection, the invention uses mineral water and SCM676/1 for practical analysis. Respectively taking mineral water and SCM676/1 water, adding into the prepared kit, and measuring F in the kit according to visual experiment steps^-And (4) concentration. By adding different concentrations of F to the actual sample^-To prepare a spiked sample, determine F by Standard addition^-Recovery in the actual sample.

As shown in Table 3, inventive pair F^-The recovery rate is between 97.47 and 110.62 percent, and the RSD is less than 7 percent. Experiments prove that the invention is F^-The actual detection of (2) has potential application value.

Table 3 determination and recovery tests of F-in complex environmental water samples.

Wherein: SCM676/1 concentration was 20-fold dilution of the original solution to the linear range of detection for this method.

The protection of the present invention is not limited to the above embodiments. Variations and advantages that may occur to those skilled in the art may be incorporated into the invention without departing from the spirit and scope of the inventive concept, and the scope of the appended claims is intended to be protected.

Claims

1. A method for synthesizing Fe-MOFs (iron-based metal organic frameworks) is characterized in that Fe is used as a raw material in a solvent³⁺3, 5-dicarboxyphenyl boric acid (5-bop) is taken as a ligand, and the reaction is carried out under the action of a regulator to obtain the Fe-MOFs.

2. The method of claim 1, wherein the solvent is N, N-dimethylformamide DMF.

3. The method of claim 1, wherein the Fe can be provided³⁺The compound (A) is one or more of ferric trichloride hexahydrate and ferric nitrate nonahydrate.

4. The method of claim 1, wherein the modulating agent is acetic acid.

5. The method of claim 1, wherein the 3, 5-dicarboxyphenylboronic acid, Fe³⁺The molar ratio of the regulator is 1:1:5, 1:2:10, 2:1:10, or 1:1: 10.

6. The process according to claim 1, wherein the reaction temperature is 120 ℃ and the reaction time is 12 hours.

7. The method of claim 1, wherein the reaction is carried out in an oil bath.

8. Fe-MOFs an iron-based metal organic framework material obtainable by a process as claimed in any one of claims 1 to 7.

9. The Fe-MOFs of claim 8, wherein the Fe-MOFs are rod-shaped with a particle size of about 200 nm.

10. The Fe-MOFs of the Fe-based metal organic framework material of claim 8, detecting F^-The use of (1).

11. A portable kit comprising the Fe-MOFs, TMB, agarose of the Fe-based metal organic framework material of claim 8.

12. The portable kit of claim 11, wherein the agarose in the kit is present in an amount of 0.2 to 1.0% by weight; wherein the content of Fe-MOFs in the kit is 1-10 mug/mL.

13. The Fe-MOFs for the Fe-based metal organic framework material according to claim 8 or the portable kit according to claim 12 for detecting F^-The use of (1).

14. Use according to claim 13, wherein F is^-The reaction time with the hydrogel is 5-120 min.