阅读说明：本技术 一种中空半球型镧系荧光印迹传感器的制备方法及应用 (Preparation method and application of hollow hemispherical lanthanide fluorescent imprinted sensor ) 是由 胡博 陈厉 徐叶青 戴江栋 汪云云 马中飞 闫永胜 于 2019-08-30 设计创作，主要内容包括：本发明属于环境检测功能材料制备技术领域,公开了一种中空半球型镧系荧光印迹传感器的制备方法及其用途。首先制备出镧系配合物Eu(MAA)<Sub>3</Sub>phen,通过使用功能化SiO<Sub>2</Sub>纳米微球为基底,以表面印迹法制备了以2,4,6-三氯苯酚为目标物的核壳型荧光印迹材料并以索氏提取法将2,4,6-三氯苯酚洗脱,最后通过牺牲基质法以氢氟酸溶解SiO<Sub>2</Sub>纳米微球制得中空半球型荧光印迹材料,并将其用于特异性检测自然水体中的2,4,6-三氯苯酚。本发明通过简单的制备方法和简便的操作流程制备出具有特殊结构的荧光印迹传感器,通过中空半球结构提高印迹层的特异性识别位点的利用率及印迹材料和目标物之间的传质速率并最终提高该传感器的灵敏度。(The invention belongs to the technical field of preparation of environment detection functional materials, and discloses a preparation method and application of a hollow hemispherical lanthanide fluorescent imprinted sensor. Firstly, preparing lanthanide complex Eu (MAA) 3 phen, by using functionalized SiO 2 The nanometer microsphere is used as a substrate, a surface imprinting method is used for preparing a core-shell type fluorescent imprinting material which takes 2,4, 6-trichlorophenol as a target object, a Soxhlet extraction method is used for eluting the 2,4, 6-trichlorophenol, and finally a sacrificial matrix method is used for dissolving SiO by hydrofluoric acid 2 The hollow hemispherical fluorescent imprinting material is prepared from the nano-microspheres and is used for specifically detecting 2,4, 6-trichlorophenol in natural water. The fluorescent imprinting sensor with the special structure is prepared by a simple preparation method and a simple operation process, the utilization rate of the specific recognition site of the imprinting layer and the mass transfer rate between the imprinting material and a target are improved by the hollow hemisphere structure, and finally the sensitivity of the sensor is improved.)

1. A preparation method of a hollow hemispherical lanthanide fluorescent imprinted sensor is characterized by comprising the following steps of:

(1) lanthanide complexes Eu (MAA)₃preparation of phen:

dissolving europium oxide in concentrated hydrochloric acid, and purifyingWashing with water and ethanol, and drying to obtain EuCl₃·6H₂O; mixing EuCl at a certain ratio₃·6H₂Dissolving O and methacrylic acid MAA in absolute ethyl alcohol, adjusting pH, adding phenanthroline phen, and collecting the product to obtain lanthanide complex Eu (MAA)₃phen；

(2) Functionalized SiO₂Preparing the nano microspheres:

a certain amount of tetraethyl orthosilicate TEOS is dripped into absolute ethyl alcohol, and ammonia NH is dripped after magnetic stirring for a certain time₃·H₂O, continuously stirring for a proper time, dripping KH570, sealing, heating, magnetically stirring, washing the obtained solid precipitate, and vacuum drying to obtain surface functionalized SiO₂Nano-microspheres;

(3) preparing a hollow hemispherical lanthanide fluorescent imprinted sensor:

surface-functionalized SiO prepared in step (2)₂Dispersing the nanometer microsphere as a substrate material into acetonitrile by ultrasonic, adding template molecules of 2,4, 6-trichlorophenol 2,4,6-TCP and MAA and Eu (MAA) prepared in the step (1)₃phen, pre-assembling for a certain time, adding ethylene glycol dimethacrylate EGDMA and azobisisobutyronitrile AIBN, heating and stirring under the condition of keeping out of the sun to prepare a core-shell lanthanide fluorescent imprinted material, centrifuging, washing, drying in vacuum, eluting template molecules by using a Soxhlet extraction method, adding the product into a polytetrafluoroethylene beaker filled with hydrofluoric acid HF, sealing, magnetically stirring and dissolving SiO₂And centrifuging, washing and vacuum drying the nano microspheres to obtain the hollow hemispherical lanthanide fluorescent imprinted sensor.

2. The method for preparing a hollow hemispherical lanthanide fluorescent imprinted sensor as claimed in claim 1, wherein in the step (1), the EuCl is prepared₃·6H₂O: MAA: the dosage ratio of phen is 1.866g, 1.31mL, 0.991g, and the pH is 8.0.

3. The method for preparing a hollow hemispherical lanthanide fluorescent imprinted sensor as claimed in claim 1, wherein in the step (2), the ratio of TEOS: NH (NH)₃·H₂Volume of OAt a ratio of 1.67:2.0, with NH₃·H₂The addition time of O is controlled after the system is stirred for 3min, and the magnetic stirring is carried out for 24h before the KH570 is added.

4. The method for preparing a hollow hemispherical lanthanide fluorescent imprinted sensor as claimed in claim 1, wherein in the step (2), the temperature is 40 ℃ and the time is 24 hours while the sensor is sealed, heated and magnetically stirred.

5. The method for preparing a hollow hemispherical lanthanide fluorescent imprinted sensor as claimed in claim 1, wherein in step (3), the surface functionalized SiO is used₂Nanometer microsphere, 2,4,6-TCP, MAA, Eu (MAA)₃The dosage ratio of phen, EGDMA, AIBN and hydrofluoric acid is 0.1 g: 0.39 g: 0.173 g: 0.186 g: 1.88 mL: 0.05 g: 20 mL; wherein, the HF concentration is 0.5mL/L, and the reaction time is 2 h.

6. The method for preparing a hollow hemispherical lanthanide fluorescent imprinted sensor as claimed in claim 1, wherein in step (3), the pre-assembly time is 30min, and the temperature is 60 ℃ and the time is 24h when the sensor is heated and stirred under the condition of keeping out of the light.

7. A hollow hemispherical lanthanide fluorescent imprinted sensor, characterized in that it is prepared by the preparation method of any one of claims 1 to 6.

8. The application of the hollow hemispherical lanthanide fluorescent imprinted sensor as claimed in claim 7, wherein the sensor is applied to detect trace 2,4, 6-trichlorophenol in natural water.

Technical Field

The invention belongs to the technical field of preparation of environment detection functional materials, and relates to a preparation method of a hollow hemispherical lanthanide fluorescent imprinted sensor and application of the hollow hemispherical lanthanide fluorescent imprinted sensor in selective detection of potential 2,4, 6-trichlorophenol in natural water.

Background

Chlorophenols are artificially synthesized organic compounds, which are mainly used for synthesizing pesticides, wood preservatives, herbicides and other substances. Numerous studies have demonstrated that chlorophenols and their derivatives have adverse effects on the human body, that this class of substances is carcinogenic and genotoxic, and even that prenatal chlorophenol exposure in fetuses can be caused by maternal-infant transmission, and that chlorophenols have been listed as the priority pollutant in the united states in 2007. The chlorophenols include mono-, di-, tri-, tetra-and pentachlorophenols, which are widely distributed in natural environment. 2,4, 6-trichlorophenol (2,4,6-TCP) is one of representative chlorophenols, and 2,4,6-TCP is strong in toxicity, is difficult to degrade under natural conditions, and is a durable toxic chemical pollutant. Therefore, the environmental monitoring and detection are particularly important, especially for monitoring human living water sources.

Among various analysis methods for daily detection of chlorophenols, the fluorescence analysis method has the characteristics of high sensitivity, simple and portable instrument, visual and even visual analysis result and the like, and is suitable for field detection of pollutants in water samples under various conditions. The lanthanide complex has outstanding optical properties in a plurality of fluorescent materials, and the fluorescence analysis method based on the lanthanide complex has the advantages of wide application range, high sensitivity, wide color gamut range and strong photobleaching resistance. However, lanthanide complexes are poor in selectivity, insufficient in thermal and chemical stability, difficult to distinguish target analytes in complex systems, and difficult to apply in extreme environments. The combination of the molecularly imprinted polymer with specific selectivity and extreme environment tolerance with the lanthanide compound-based fluorescence sensor can achieve both high sensitivity and specific selectivity. The fluorescent imprinting sensor can realize simple and sensitive selective recognition on chlorophenols and has important significance for detecting 2,4,6-TCP in natural water samples on site.

Disclosure of Invention

Compared with the traditional core-shell type fluorescence print sensor, the hollow print sensor obtained by the method has higher mass transfer rate, can make full use of specific recognition sites in the print layer, and effectively improves the sensitivity of the sensor. Compared with the traditional hollow spherical structure, the inner surface of the imprinting layer is more effectively utilized, and the sensitivity of the imprinting layer to the 2,4,6-TCP is further enhanced due to the improvement of the utilization rate of the specific recognition sites of the whole imprinting layer.

A preparation method and application of a hollow hemispherical lanthanide fluorescent imprinted sensor specifically comprise the following steps:

(1) lanthanide complexes Eu (MAA)₃preparation of phen:

dissolving europium oxide in concentrated hydrochloric acid, washing the product with absolute ethyl alcohol and drying to obtain EuCl₃·6H₂O; mixing EuCl at a certain ratio₃·6H₂Dissolving O and methacrylic acid MAA in absolute ethyl alcohol, adjusting pH, adding phenanthroline phen, and collecting the product to obtain lanthanide complex Eu (MAA)₃phen；

(2) Functionalized SiO₂Preparing the nano microspheres:

a certain amount of tetraethyl orthosilicate TEOS is dripped into absolute ethyl alcohol, and ammonia NH is dripped after magnetic stirring for a certain time₃·H₂O, continuously stirring for a proper time, dripping KH570, sealing, heating, magnetically stirring, washing the obtained solid precipitate, and vacuum drying to obtain surface functionalized SiO₂Nano-microspheres;

(3) preparing a hollow hemispherical lanthanide fluorescent imprinted sensor:

surface-functionalized SiO prepared in step (2)₂Dispersing the nanometer microsphere as a substrate material into acetonitrile by ultrasonic, adding template molecules of 2,4, 6-trichlorophenol 2,4,6-TCP and MAA and Eu (MAA) prepared in the step (1)₃phen, pre-assembling for a certain time, adding ethylene glycol dimethacrylate EGDMA and azobisisobutyronitrile AIBN, heating and stirring under the condition of keeping out of the sun to obtain a core-shell type lanthanide series fluorescent imprinted material, centrifuging, washing, drying in vacuum, and extracting by using SoxhletEluting template molecules by the method, adding the product into a polytetrafluoroethylene beaker filled with hydrofluoric acid HF, sealing, magnetically stirring and dissolving SiO₂And centrifuging, washing and vacuum drying the nano microspheres to obtain the hollow hemispherical lanthanide fluorescent imprinted sensor.

In the step (1), the EuCl₃·6H₂O: MAA: the dosage ratio of phen is 1.866g, 1.31mL, 0.991g, and the pH is 8.0.

In the step (2), the TEOS: NH (NH)₃·H₂O in a volume ratio of 1.67:2.0 and NH₃·H₂The addition time of O is controlled after the system is stirred for 3min, and the magnetic stirring is carried out for 24h before the KH570 is added.

In the step (2), the temperature is 40 ℃ and the time is 24 hours when the mixture is sealed, heated and magnetically stirred.

In step (3), surface-functionalized SiO₂Nanometer microsphere, 2,4,6-TCP, MAA, Eu (MAA)₃The dosage ratio of phen, EGDMA, AIBN and hydrofluoric acid is 0.1 g: 0.39 g: 0.173 g: 0.186 g: 1.88 mL: 0.05 g: 20 mL; wherein, the HF concentration is 0.5mL/L, and the reaction time is 2 h.

In the step (3), the preassembly time is 30min, and the temperature is 60 ℃ and the time is 24h when the mixture is heated and stirred under the condition of keeping out of the sun.

In the step (3), when the Soxhlet extraction method is used for eluting the template molecules, an acetic acid/methanol mixed solution is used, and the volume ratio of the acetic acid/methanol mixed solution is 10: 90.

the preparation method of the corresponding non-imprinted polymer of the invention is similar to the synthesis method above, but the template molecule 2,4,6-TCP is not added.

The hollow hemispherical lanthanide fluorescent imprinted sensor prepared by the invention is used for quickly and sensitively detecting potential 2,4,6-TCP in natural water, and has excellent anti-interference capability on chlorophenols with similar structures.

The invention has the beneficial effects that:

(1) the lanthanide series complex is combined with the molecular imprinting technology, and the lanthanide series complex has the advantages of high sensitivity of lanthanide series materials, specific selectivity of the molecular imprinting technology, good stability and environmental tolerance.

(2) The hollow hemispherical material prepared by the invention has uniform particle size and stable structure, and the novel hollow hemispherical structure effectively improves the utilization rate of specific recognition sites in a molecular imprinting layer, improves the mass transfer rate between a target object and the imprinting layer, and further improves the sensitivity of a sensor.

(3) The preparation method is simple and easy to implement, short in process, easy to control in operation and suitable for popularization and application.

Drawings

FIG. 1 shows Eu (MAA)₃phen contour fluorescence spectrogram;

FIG. 2 shows Eu (MAA) according to FIG. 1₃The maximum emission wavelength of the complex and the corresponding excitation wavelength determined by the phen fluorescence contour diagram;

FIG. 3 is a view of a functionalized SiO₂Scanning electron microscope and transmission electron microscope of the nano microspheres (a, d, g), core-shell imprinting materials (b, e, h) and hollow hemispherical imprinting materials (c, f, i) and average particle size data graphs obtained by a laser particle sizer;

FIG. 4 shows Eu (MAA)₃The corresponding fluorescence intensities of phen at different solution pH;

FIG. 5 shows the fluorescence intensity of the hollow hemispherical fluorescence blotting sensor under different pH of the solution;

FIG. 6 is a response curve of a hollow hemispherical fluorescent imprinted sensor to 10-100nmol/L of 2,4, 6-trichlorophenol;

FIG. 7 is a graph showing the response of non-imprinted materials to 10-100nmol/L of 2,4, 6-trichlorophenol;

FIG. 8 shows the quenching amounts of different chlorophenols at the same concentration (100nmol/L) for the imprinted and non-imprinted materials.

Detailed Description

In the specific embodiment of the invention, the identification and fluorescence detection performance evaluation is carried out according to the following method: adding 5ml of 2,4,6-TCP with unknown concentration into a colorimetric tube, adjusting the pH value to 7.0, adding 5mg of imprinting material, magnetically stirring at low speed for 10min at room temperature, detecting the fluorescence intensity of the solution by using a fluorescence spectrophotometer, and determining the concentration of a target object according to a standard curve in a corresponding concentration range. Wherein 2,4-, 2,5-, 2, 6-dichlorophenol is used as a structural analogue to participate in the research of the identification performance of the fluorescent imprinting material.

The invention is further illustrated by the following examples.