阅读说明：本技术 一种Fe-CDs和MOF-808复合材料用于降解、检测有机磷农药的方法 (Method for degrading and detecting organophosphorus pesticide by using Fe-CDs and MOF-808 composite material ) 是由 张信凤 杨娇娇 欧琪 牟一敏 马雪娟 于 2021-09-01 设计创作，主要内容包括：一种基于铁掺杂的碳点(Fe-CDs)和金属锆形成的有机框架(MOF-808)复合材料的有机磷化合物降解、检测一体化方法,主要通过两种方式形成Fe-CDs嵌入在MOF-808孔道里面的Fe-CDs/MOF-808和Fe-CDs附着在MOF-808表面的Fe-CDs@MOF-808复合材料。二者均可降解有机磷化合物产生对硝基苯酚,通过内滤效应猝灭Fe-CDs的荧光,实现有机磷化合物的降解检测。Fe-CDs/MOF-808是通过在室温条件下MOF-808催化对氧磷水解产生对硝基苯酚；Fe-CDs@MOF-808是通过在光照条件下,利用Fe-CDs的光敏氧化性能,通过所产生的～(1)O-(2)和·O-(2)～(-)等活性氧物种光催化降解对硫磷产生对硝基苯酚。本方法对有机磷农药降解、检测速度快,具有较宽的检测线性范围以及较低的检出限,可应用于实际水样以及果蔬样品中有机磷化合物的降解、检测。(An organic phosphorus compound degradation and detection integrated method based on an organic framework (MOF-808) composite material formed by iron-doped carbon dots (Fe-CDs) and metal zirconium mainly forms an Fe-CDs/MOF-808 composite material with Fe-CDs embedded in the pore channels of the MOF-808 and an Fe-CDs @ MOF-808 composite material with Fe-CDs attached to the surface of the MOF-808 in two ways. Both the two can degrade the organic phosphorus compound to generate p-nitrophenol, and the fluorescence of Fe-CDs is quenched through an internal filtration effect, so that the degradation detection of the organic phosphorus compound is realized. Fe-CDs/MOF-808 is prepared by MOF-808 catalysis at room temperatureHydrolyzing paraoxon to generate paranitrophenol; Fe-CDs @ MOF-808 is produced by utilizing the photo-oxidative properties of Fe-CDs under light conditions 1 O 2 And O 2 ‑ The active oxygen species are used for photocatalytic degradation of parathion to generate p-nitrophenol. The method has high degradation and detection speed on the organophosphorus pesticide, has a wider detection linear range and a lower detection limit, and can be applied to degradation and detection of organophosphorus compounds in actual water samples and fruit and vegetable samples.)

1. A method for degrading and detecting organophosphorus pesticide by using Fe-CDs and MOF-808 composite material is characterized by comprising the following steps:

(1) preparation of a composite material (Fe-CDs/MOF-808) based on embedding iron-doped carbon dots (Fe-CDs) into an organic framework (MOF-808) formed of metallic zirconium: adding 0.1175 g of 1,3, 5-benzenetricarboxylic acid and 0.54 g of zirconium oxychloride octahydrate into a beaker, adding 25 mL of N, N-dimethylformamide and formic acid respectively, carrying out ultrasonic treatment on the mixed solution for 30min, adding 2 mL of Fe-CDs, transferring the solution in the beaker into a 100 mL polytetrafluoroethylene reaction kettle, and putting the reaction kettle into an electrothermal constant-temperature drying box at 120 ℃ for reaction for 48 hours; after the reaction is finished, washing the reaction product for a plurality of times by using DMF and acetone, and carrying out vacuum drying and activation for 12 hours;

(2) preparation of composite materials based on Fe-CDs attached to the surface of MOF-808 (Fe-CDs @ MOF-808): preparation of MOF-808: adding a mixed solution of 0.1175 g of 1,3, 5-benzenetricarboxylic acid, 0.54 g of zirconium oxychloride octahydrate and 25 mL of N, N-dimethylformamide and formic acid into a beaker, carrying out ultrasonic mixing uniformly, transferring the solution in the beaker into a 100 mL polytetrafluoroethylene reaction kettle, and putting the reaction kettle into an electrothermal constant-temperature drying oven at 120 ℃ for reacting for 48 hours; after the reaction is finished, washing the reaction product for a plurality of times by using DMF and acetone, and carrying out vacuum drying and activation for 12 hours; adding 50-200 mg of MOF-808 into 2 mL of Fe-CDs solution, stirring for 12 h on a magnetic stirring instrument at normal temperature, washing the precipitate for several times by using DMF (dimethyl formamide), deionized water and acetone under the action of ultrasound and centrifugation, drying in vacuum, and activating for 12 h;

(3) degradation detection of paraoxon: preparing the Fe-CDs/MOF-808 into a suspension of 0.1-0.6 mg/mL, and carrying out ultrasonic treatment for 30 min; adding Fe-CDs/MOF-808 suspension and paraoxon into a centrifugal tube, slightly oscillating on an oscillator, centrifuging, taking supernatant, and measuring the content of paraoxon before and after degradation by high performance liquid chromatography so as to calculate the degradation rate of paraoxon; the rapid detection of the paraoxon is realized through the change of fluorescence before and after the paraoxon is added;

(4) and (3) detecting parathion through photocatalytic degradation: 50-200 mg of MOF-808 added in the Fe-CDs @ MOF-808 material is prepared, 0.5 mg/mL of ultrasound is prepared for 30min by using a suspension, Fe-CDs @ MOF-808 suspension and parathion are added in a small pore plate, the solution is irradiated for 5-30min by using a lamp to realize photocatalytic degradation of parathion, a supernatant is taken after centrifugation, and the parathion content before and after degradation is measured by high performance liquid chromatography, so that the degradation rate of the parathion is calculated; the rapid detection of parathion is realized through the change of fluorescence before and after the parathion is added.

2. The method of claim 1, wherein in step (3) the material used is a nanocomposite of Fe-CDs intercalated MOF-808 at a concentration of 0.1-0.6 mg/mL.

3. The method of claim 1, wherein in step (4), the material used is a Fe-CDs-attached MOF-808 nanocomposite, at a concentration of 0.5 mg/mL, and the MOF-808 is added in an amount of 50-200 mg.

4. The method of claim 1, wherein in step (4), the light source is a violet LED lamp and the illumination time is 5-30 min.

Technical Field

The invention discloses a method for degrading and detecting organophosphorus pesticide by using Fe-CDs and MOF-808 composite material, belonging to the technical field of environmental protection.

Background

In recent years, organic phosphorus compounds (OPs) have been used in large amounts as pesticides, and have a certain influence on the environment during use. Meanwhile, the massive exposure of human beings to organophosphorus pesticides can cause acute myocardial injury, cognitive impairment and neuropsychiatric diseases. Therefore, there is a need to develop methods for degrading and detecting organophosphorus compounds. The organophosphorus hydrolase is mainly used for degrading organophosphorus compounds at present, but is difficult to prepare and has limited sources, so that the application of the organophosphorus hydrolase is limited. Methods for detecting organophosphorus compounds include methods such as mass spectrometry, high performance liquid chromatography-mass spectrometry, and the like, and although the methods have high sensitivity, the methods cannot realize detection under conditions outside a laboratory due to expensive instruments and complex pretreatment processes. In contrast, the metal zirconium organic framework MOF-808 material is favored by many people due to the advantages of easy raw material availability, simple synthesis and the like, is often used as an artificial mimic enzyme for degrading organophosphorus pesticides, but cannot realize the integration of degradation and detection due to the non-fluorescence property. In order to solve the problem, an integrated method for degrading and detecting an organophosphorus compound is constructed by utilizing an adjustable structure of a pore passage of MOF-808 and the adsorption performance of the adjustable structure and the adsorption performance of the pore passage, and further combining an iron-doped carbon quantum dot with the MOF-808, on one hand, the simulated enzyme characteristic of the MOF-808 is utilized, and on the other hand, the fluorescence and photosensitive performance of the carbon quantum dot is utilized.

Disclosure of Invention

The invention aims to construct an organic phosphorus compound degradation and detection integrated method based on a Fe-CDs and MOF-808 composite material. Firstly, preparing a composite material Fe-CDs/MOF-808 of iron-doped carbon dots (Fe-CDs) and a metal zirconium organic framework (MOF-808), carrying out catalytic degradation on paraoxonium by the MOF-808 at room temperature to generate paranitrophenol, and realizing rapid detection on paraoxonium by the fluorescent inner filtering effect of the paranitrophenol on the Fe-CDs/MOF-808 so as to achieve integrated degradation and detectionThe purpose of paraoxon. The Fe-CDs are attached to the surface of the MOF-808 to form a composite material (Fe-CDs @ MOF-808), have good photosensitive property, and generate a large amount of light under room temperature illumination conditions¹O₂And O₂ ^-And the active oxygen substances are equal, and the generated active oxygen substances can effectively degrade parathion. The generated p-nitrophenol quenches the fluorescence of Fe-CDs @ MOF-808 through an inner filtering effect, and the degradation and detection of parathion are realized based on the fluorescence. The technical scheme of the invention is as follows:

(1) preparation of a composite material (Fe-CDs/MOF-808) based on embedding iron-doped carbon dots (Fe-CDs) into an organic framework (MOF-808) formed of metallic zirconium: adding 0.1175 g of 1,3, 5-benzenetricarboxylic acid and 0.54 g of zirconium oxychloride octahydrate into a beaker, adding 25 mL of N, N-dimethylformamide and formic acid respectively, carrying out ultrasonic treatment on the mixed solution for 30min, adding 2 mL of Fe-CDs, transferring the solution in the beaker into a 100 mL polytetrafluoroethylene reaction kettle, and placing the reaction kettle into an electrothermal constant-temperature drying box at 120 ℃ for reaction for 48 hours. After the reaction is finished, washing the reaction product with DMF and acetone for a plurality of times, drying the reaction product in vacuum and activating the reaction product for 12 hours.

(2) Preparation of composite materials based on Fe-CDs attached to the surface of MOF-808 (Fe-CDs @ MOF-808): preparation of MOF-808: adding a mixed solution of 0.1175 g of 1,3, 5-benzenetricarboxylic acid, 0.54 g of zirconium oxychloride octahydrate, 25 mL of N, N-dimethylformamide and formic acid into a beaker, carrying out ultrasonic mixing uniformly, transferring the solution in the beaker into a 100 mL polytetrafluoroethylene reaction kettle, and putting the reaction kettle into an electrothermal constant-temperature drying oven at 120 ℃ for reacting for 48 hours. After the reaction is finished, washing the reaction product with DMF and acetone for a plurality of times, drying the reaction product in vacuum and activating the reaction product for 12 hours. Adding 50-200 mg of MOF-808 into 2 mL of Fe-CDs solution, stirring for 12 h on a magnetic stirring instrument at normal temperature, washing the precipitate for several times by DMF, deionized water and acetone under the action of ultrasound and centrifugation, drying in vacuum, and activating for 12 h.

(3) Degradation detection of paraoxon: the Fe-CDs/MOF-808 is prepared into a suspension of 0.1-0.6 mg/mL and is subjected to ultrasonic treatment for 30 min. Adding Fe-CDs/MOF-808 suspension and paraoxon into a centrifugal tube, slightly oscillating on an oscillator, centrifuging, taking supernatant, and measuring the content of paraoxon before and after degradation by high performance liquid chromatography so as to calculate the degradation rate of paraoxon; the rapid detection of the paraoxon is realized through the change of fluorescence before and after the paraoxon is added.

(4) And (3) detecting parathion through photocatalytic degradation: 50-200 mg of MOF-808 added in the Fe-CDs @ MOF-808 material is prepared, the suspension is prepared into 0.1-0.6 mg/mL ultrasonic for 30min, Fe-CDs @ MOF-808 suspension and parathion are added in a small pore plate, the solution is irradiated by a lamp for 5-30min to realize photocatalytic degradation of parathion, supernatant is taken after centrifugation, the parathion content before and after degradation is determined by high performance liquid chromatography, and thus the degradation rate of parathion is calculated; the rapid detection of parathion is realized through the change of fluorescence before and after the parathion is added.

Effects of the invention

Compared with the prior art, the invention has the following advantages:

(1) the nanocomposite material (Fe-CDs/MOF-808) with Fe-CDs embedded in MOF-808 can realize the integration of degradation and detection of paraoxon;

(2) the Fe-CDs attached MOF-808 nano composite material (Fe-CDs @ MOF-808) can realize the integration of degradation and detection of parathion;

(3) the fast detection of paraoxon and parathion can be realized without using chromatographic separation;

(4) can be used for degrading and detecting organic phosphorus in actual water samples and vegetable samples.

Detailed Description

Example 1

Adding a mixed solution of 0.1175 g of 1,3, 5-benzenetricarboxylic acid, 0.54 g of zirconium oxychloride octahydrate, 25 mL of N, N-dimethylformamide and formic acid into a beaker, carrying out ultrasonic treatment for 30 minutes, adding 2 mL of Fe-CDs, transferring the solution in the beaker into a 100 mL polytetrafluoroethylene reaction kettle, and placing the kettle into an electrothermal constant-temperature drying oven at 120 ℃ for reaction for 48 hours. After the reaction, the reaction mixture was washed with DMF and acetone several times and dried at 25 ℃. Activating for 12 hours in a vacuum drying oven at 120 ℃ to prepare Fe-CDs/MOF-808.

And (3) preparing the prepared Fe-CDs/MOF-808 nano composite material into 1.2 mg/mL suspension, and carrying out ultrasonic treatment for 30 min. Sequentially adding N-ethylmorpholine buffer solution (NEM), 100 mu M paraoxon and 0.1-0.6 mg/mL of the above solutions, slightly oscillating the solutions on an oscillator at room temperature for 5min, and determining degradation and detection effects. When the concentration of Fe-CDs/MOF-80 is 0.3 mg/mL, the degradation rate of paraoxon is 73 percent, the concentration is 0.5 mg/mL, the degradation rate reaches 100 percent, and the fluorescence quenching effect is strongest when the concentration is 0.5 mg/mL, the detection linear range is 0.001-360 mu M, and the detection limit can reach 0.5 nM.

And taking 150 mg of MOF-808 added into 2 mL of Fe-CDs solution, and stirring for 12 h on a magnetic stirrer at room temperature to obtain Fe-CDs @ MOF-808. Washing the precipitate with DMF, deionized water and acetone under the action of ultrasound and centrifugation for several times, and activating the synthesized material in a vacuum drying oven at 120 deg.C for 12 h.

Preparing the prepared Fe-CDs @ MOF-808 nano material into 1.2 mg/mL suspension, performing ultrasonic treatment for 30min, sequentially adding N-ethylmorpholine buffer solution (NEM), 10 mu M parathion and 0.5 mg/mL solution, performing illumination reaction for 5-30min under an ultraviolet LED lamp at room temperature, and determining degradation and detection effects. When the added MOF-808 is 150 mg, the concentration of the suspension of Fe-CDs @ MOF-808 is 0.5 mg/mL, the illumination is 5min, and the degradation rate of parathion is 80%: when the light is irradiated for 10 min, the degradation rate is 100 percent; and the fluorescence quenching effect is strongest under the condition of illumination for 10 min, the linear range of parathion detection is 0.01-100 mu M, and the detection limit can reach 5 nM.

Example 2

And (3) adding 50-200 mg of MOF-808 into 2 mL of Fe-CDs solution, and stirring for 12 h on a magnetic stirring instrument at room temperature to obtain Fe-CDs @ MOF-808. Washing the precipitate with DMF, deionized water and acetone under the action of ultrasound and centrifugation for several times, and activating the synthesized material in a vacuum drying oven at 120 deg.C for 12 h.

Preparing the prepared Fe-CDs @ MOF-808 nano material into 1.2 mg/mL suspension, performing ultrasonic treatment for 30min, sequentially adding N-ethylmorpholine buffer solution (NEM), 10 mu M parathion and 0.5 mg/mL solution, performing light reaction for 10 min under an ultraviolet LED lamp at room temperature, and determining degradation and detection effects. The concentration of the suspension of Fe-CDs @ MOF-808 is 0.5 mg/mL, and when the illumination is carried out for 10 min and the added MOF-808 is 50 mg, the degradation rate of parathion is 87%; the added MOF is 150 mg, the degradation rate is 100%, the fluorescence quenching effect is strongest, the detection linear range is 0.01-100 mu M, and the detection limit can reach 5 nM.

An organic phosphorus compound degradation and detection integrated method based on an organic framework (MOF-808) composite material formed by iron-doped carbon dots (Fe-CDs) and metal zirconium mainly forms an Fe-CDs/MOF-808 composite material with Fe-CDs embedded in the pore channels of the MOF-808 and an Fe-CDs @ MOF-808 composite material with Fe-CDs attached to the surface of the MOF-808 in two ways. Both the two can degrade the organic phosphorus compound to generate p-nitrophenol, and the fluorescence of Fe-CDs is quenched through an internal filtration effect, so that the degradation detection of the organic phosphorus compound is realized. Fe-CDs/MOF-808 is used for catalyzing the hydrolysis of paraoxon by MOF-808 at room temperature to generate paranitrophenol; Fe-CDs @ MOF-808 is produced by utilizing the photo-oxidative properties of Fe-CDs under light conditions¹O₂And O₂ ^-The active oxygen species are used for photocatalytic degradation of parathion to generate p-nitrophenol. The method has high degradation and detection speed on the organophosphorus pesticide, has a wider detection linear range and a lower detection limit, and can be applied to degradation and detection of organophosphorus compounds in actual water samples and fruit and vegetable samples.