Sensor material based on lanthanide metal organic framework as well as preparation method and application of sensor material

Abstract

The invention discloses a sensor material based on a lanthanide metal organic framework as well as a preparation method and application thereof, and belongs to the technical field of white spirit detection. The sensor material based on the lanthanide metal organic framework is a composite material formed by adding lanthanide metal terbium or europium into the metal organic framework for modification, and is an Eu-MOF (at) Eu-MOF material, a Tb-MOF (at) Tb-MOF material or an Eu-MOF (at) Tb-MOF material. A fluorescent sensing array with 11 sensing channels is constructed by taking Eu-MOF (at) Eu-MOF, Tb-MOF (at) Tb-MOF or Eu-MOF (at) Tb-MOF material as a probe, so that the organic substances and the Luzhou-flavor liquor are detected, and the fluorescent sensing array has the advantages of high sensitivity, short detection time, short response time, good portability and the like, and is very suitable for rapid detection of the Luzhou-flavor liquor.

Description

Technical Field

[0001] The invention belongs to the technical field of liquor detection, and specifically relates to a sensor material based on a lanthanide metal organic framework, and a preparation method and application thereof. Background Art

[0002] With the improvement of national economy and living standards, as well as the deepening of consumers' rational consumption concept, the quality requirements for Luzhou-flavor liquor are getting higher and higher. The complex brewing process makes it easy for the liquor to introduce impurities or be contaminated during the production process. There are also unscrupulous vendors who want to make profits from it, and various counterfeit and inferior products appear. At present, the traditional liquor detection methods include sensory evaluation, high-performance liquid chromatography, gas chromatography and chromatography-mass spectrometry. Sensory evaluation is the most widely used detection method at present, which mainly relies on the taster's sense of smell, taste, vision and touch to evaluate and divide the grade and quality of liquor. Sensory evaluation is easily disturbed by the taster himself and the surrounding environment, and there are large errors, and it cannot form a standardized detection method. High-performance liquid chromatography, gas chromatography and chromatography-mass spectrometry technology all require large instruments and equipment for detection, which have the disadvantages of subjectivity, expensive instruments and equipment, and cumbersome operation, and are not suitable for liquor detection. Summary of the invention

[0003] The purpose of the present invention is to provide a lanthanide metal organic framework and quantum dot doped metal organic framework sensor material for effectively detecting Luzhou-flavor liquor, as well as a preparation method and application thereof.

[0004] In order to achieve the above-mentioned object of the invention, the technical solution provided by the present invention is as follows:

[0005] In a first aspect, the present invention provides a sensor material based on a lanthanide metal organic framework, wherein the sensor material is a composite material modified by adding lanthanide metal terbium or europium to the metal organic framework, and is Eu-MOF@Eu-MOF, Tb-MOF@Tb-MOF or Eu-MOF@Tb-MOF material.

[0006] In a second aspect, the present invention provides a method for preparing the above-mentioned sensor material based on lanthanide metal organic framework, comprising the following steps:

[0007] (1) Synthesizing Eu-MOF or Tb-MOF materials by hydrothermal method;

[0008] (2) Based on Eu-MOF or Tb-MOF materials, a hydrothermal method is used to in situ synthesize Eu-MOF@Eu-MOF, Tb-MOF@Tb-MOF or Eu-MOF@Tb-MOF materials.

[0009] In the above preparation method, in step (1) or (2), the specific synthesis method is: after the synthetic raw materials and terephthalic acid are dissolved in DMF solution, they are placed in a hydrothermal synthesis reactor for reaction, and then cooled to room temperature, washed, and vacuum dried.

[0010] Furthermore, the reaction temperature is 120° C. and the reaction time is 12 h.

[0011] Furthermore, the washing is performed by washing with DMF and first-grade water for 3 times respectively.

[0012] Furthermore, the vacuum drying is carried out at a temperature of 60° C. and for a time of 12 h.

[0013] In the above preparation method, in step (1), the raw material for synthesizing the Eu-MOF material is europium nitrate hexahydrate; the raw material for synthesizing the Tb-MOF material is terbium nitrate hexahydrate.

[0014] In the above preparation method, in step (2), the raw materials for the synthesis of Eu-MOF@Eu-MOF material are europium nitrate hexahydrate and Eu-MOF material; the raw materials for the synthesis of Tb-MOF@Tb-MOF material are terbium nitrate hexahydrate and Tb-MOF material; the raw materials for the synthesis of Eu-MOF@Tb-MOF material are europium nitrate hexahydrate and Tb-MOF material.

[0015] Furthermore, europium nitrate hexahydrate is 0.535 g; terbium nitrate hexahydrate is 0.435 g; Eu-MOF material is 0.1 g; Tb-MOF material is 0.1 g; terephthalic acid is 0.1 g; and the DMF solution is 30 mL of DMF + 15 mL of primary water.

[0016] In a third aspect, the present invention provides an application of the above-mentioned sensor material based on lanthanide metal organic frameworks, using Eu-MOF@Eu-MOF, Tb-MOF@Tb-MOF or Eu-MOF@Tb-MOF materials as probes to construct a fluorescence sensing array with 11 sensing channels to detect organic matter and Luzhou-flavor liquor.

[0017] Furthermore, the detection method of organic matter is specifically as follows: using 50% ethanol as a solvent, adding Eu-MOF@Eu-MOF, Tb-MOF@Tb-MOF or Eu-MOF@Tb-MOF materials respectively, and then adding the organic matter to be tested at a concentration of 250 μM for reaction, and testing the fluorescence intensity after the reaction.

[0018] Furthermore, the detection method of Luzhou-flavor liquor is specifically as follows: using 50% ethanol as a solvent, adding Eu-MOF@Eu-MOF, Tb-MOF@Tb-MOF or Eu-MOF@Tb-MOF materials respectively, and then adding the Luzhou-flavor liquor sample to be tested to react, and testing the fluorescence intensity after the reaction.

[0019] Furthermore, the addition amount of Eu-MOF@Eu-MOF material is 1 mg / mL; the addition amount of Tb-MOF@Tb-MOF material is 0.3 mg / mL; the addition amount of Eu-MOF@Tb-MOF material is 0.4 mg / mL; the reaction time is 20 min, and the reaction temperature is room temperature.

[0020] The beneficial effects of the present invention are as follows: MOFs are composed of a metal center and an organic ligand, and are a crystalline material having the characteristics of high porosity, large specific surface area, and diversified structure. Lanthanide metals have special 4f electronic orbital characteristics, covering the emission range from ultraviolet to near infrared. Ln-MOFs combine the excellent luminescence properties of lanthanide elements, and meet the characteristics of high sensitivity, rapid response, and good stability required for optical sensor element materials. The present invention further resynthesizes Ln-MOFs in situ, which helps the energy and energy level transformation of the lanthanide metal center and the organic ligand, further enhances the intensity of the fluorescence signal, and the multiple fluorescence signals of the lanthanide metal participate in effectively improving the detection efficiency of the sensor array. The present invention first synthesizes a single-layer MOF by a hydrothermal method, and then synthesizes a double-layer MOF again in situ. Compared with the single layer, the fluorescence signal of the double-layer MOF is stronger. The present invention constructs a fluorescent sensing array through the synthesized three Ln-MOFs, realizes the detection of organic matter and Luzhou-flavor liquor, has the advantages of high sensitivity, short detection time, fast response time and good portability, and is very suitable for the rapid detection of Luzhou-flavor liquor. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 The SEM image and EDS spectrum of the sensor material of the present invention;

[0022] Figure 2 The fluorescence spectra of the sensor material of the present invention detecting 19 kinds of Luzhou-flavor liquors;

[0023] Figure 3 This is a pattern recognition analysis diagram of the sensor material of the present invention detecting Wuliangye series liquor. DETAILED DESCRIPTION

[0024] The technical solution of the present invention can be specifically implemented in the following manner.

[0025] 1. Sensor materials based on lanthanide metal-organic frameworks

[0026] 1. Synthesis of Ln-MOFs

[0027] (1) Eu-MOF@Eu-MOF material: Weigh 0.535g europium nitrate hexahydrate and 0.1g terephthalic acid, add 30mL DMF, and mix by ultrasonic. Then add 15mL first-grade water, stir for 15min, transfer to a reactor after mixing, and the reaction temperature is 120℃ for 12h. After the reaction is completed, cool to room temperature, wash with DMF and first-grade water three times respectively, vacuum dry at 60℃ for 12h to obtain Eu-MOF powder. Weigh 0.1g Eu-MOF powder, add 0.535g europium nitrate hexahydrate, 0.1g terephthalic acid, add 30mL DMF, mix by ultrasonic, then add 15mL first-grade water, stir for 15min, transfer to a reactor after mixing, and the reaction temperature is 120℃ for 12h. After cooling to room temperature, the mixture was washed three times with DMF and primary water respectively, and vacuum dried at 60°C for 12 h to obtain Eu-MOF@Eu-MOF powder.

[0028] (2) Tb-MOF@Tb-MOF material: Weigh 0.435g of terbium nitrate hexahydrate and 0.1g of terephthalic acid, add 30mL of DMF, and mix by ultrasonic. Then add 15mL of first-grade water, stir for 15min, and transfer to a reactor after mixing. The reaction temperature is 120℃ and the reaction time is 12h. After the reaction is completed, cool to room temperature, wash with DMF and first-grade water three times respectively, and vacuum dry at 60℃ for 12h to obtain Tb-MOF powder. Weigh 0.1g of Tb-MOF powder, add 0.435g of terbium nitrate hexahydrate, 0.1g of terephthalic acid, add 30mL of DMF, mix by ultrasonic, then add 15mL of first-grade water, stir for 15min, and transfer to a reactor after mixing. The reaction temperature is 120℃ and the reaction time is 12h. After cooling to room temperature, the mixture was washed with DMF and primary water for three times, and vacuum dried at 60 °C for 12 h to obtain Tb-MOF@Tb-MOF powder.

[0029] (3) Eu-MOF@Tb-MOF material: Weigh 0.435g of terbium nitrate hexahydrate and 0.1g of terephthalic acid, add 30mL of DMF, and mix by ultrasonic. Then add 15mL of first-grade water, stir for 15min, and transfer to a reactor after mixing. The reaction temperature is 120℃ and the reaction time is 12h. After the reaction is completed, cool to room temperature, wash with DMF and first-grade water three times respectively, and vacuum dry at 60℃ for 12h to obtain Tb-MOF powder. Weigh 0.1g of Tb-MOF powder, add 0.535g of europium nitrate hexahydrate, 0.1g of terephthalic acid, add 30mL of DMF, mix by ultrasonic, then add 15mL of first-grade water, stir for 15min, and transfer to a reactor after mixing. The reaction temperature is 120℃ and the reaction time is 12h. After cooling to room temperature, the mixture was washed three times with DMF and primary water respectively, and vacuum dried at 60 °C for 12 h to obtain Eu-MOF@Tb-MOF powder.

[0030] 2. Characterization of Ln-MOFs

[0031] The prepared materials were characterized by SEM, FT-IR and XRD. Figure 1 As shown, among which: (A, B) are SEM images of Eu-MOF@Eu-MOF material; (C, D) are SEM images of Tb-MOF@Tb-MOF material; (E, F) are SEM images of Eu-MOF@TbMOF material; (G) is FT-IR image; (H) is XRD image.

[0032] Depend on Figure 1 It can be seen that the three materials all present similar flake structures, with sizes at the μm level; C, N, O, Eu and Tb elements are evenly distributed on the surface of the materials; the diffraction peaks of the three MOF materials are the same, indicating that the skeleton structures of the three materials are similar. The above characterization results all indicate the successful preparation of the materials.

[0033] 2. Application of sensor materials based on lanthanide metal-organic frameworks

[0034] 1. Detection of organic matter

[0035] Use a 500 μL centrifuge tube and 50% ethanol as the solvent, add 360 μL of Eu-MOF@Eu-MOF, Tb-MOF@Tb-MOF or Eu-MOF@Tb-MOF material respectively, and then add 40 μL of organic matter (concentration of all 250 μM) to react (room temperature, 20 min), and repeat the measurement 3 times.

[0036] The LDA mode was selected to distinguish and identify organic substances. The results showed that the detection accuracy of LDA for 19 organic substances (ethyl octanoate, 3-methyl-1-butanol, 1-propanol, acetaldehyde, ethyl formate, phthalic acid, pentanetetracol, 1-hexanol, formaldehyde, ethyl acetate, 1-butanol, glyoxylic acid, propionic acid, ethyl lactate, ethyl glutaric acid, heptanoic acid, ethyl heptanoate, and formic acid) reached 100%, indicating that the fluorescence sensing array constructed using the sensor material based on the lanthanide metal organic framework prepared by the present invention has excellent detection capability for organic matter.

[0037] 2. Detection of Luzhou-flavor Liquor

[0038] Eu-MOF@Eu-MOF, Tb-MOF@Tb-MOF or Eu-MOF@Tb-MOF materials were used to detect 19 kinds of Luzhou-flavor liquor samples; wherein, the addition amount of Eu-MOF@Eu-MOF material was 1 mg / mL; the addition amount of Tb-MOF@Tb-MOF material was 0.3 mg / mL; the addition amount of Eu-MOF@Tb-MOF material was 0.4 mg / mL; the reaction time was 20 min, the reaction temperature was room temperature, and the measurement was repeated 3 times. The information of the 19 kinds of Luzhou-flavor liquors in this example is shown in Table 1.

[0039] Table 119 Information on Luzhou-flavor Liquor

[0040] serial number Distilled spirits Alcohol content (%) serial number Distilled spirits Alcohol content (%) 1 Wuliang Touqu Premium 52 11 Wuliangye 52 2 Wuliangtouqu 52 12 Mian Rou Jian Zhuang 50 3 Wuliang Special Liquor 52 13 Sharp Village Highlights 50 4 Wuliangtequ 52 14 Jianzhuang Daguang 50 5 Wuliangchun 35° 35 15 Rich and powerful 52 6 Wuliangchun 45° 45 16 Oriental Beauty 52 7 Wuliangchun 50° 50 17 Xinglong Top Grade 52 8 Wuliangchun Silver Packaging 50 18 Hot 58 9 Wuliangchun red 50 19 Crooked Mouth 52 10 Wuliangchun Gold 50

[0041] Luzhou-flavor liquor adopts solid-state fermentation, and the fermentation process is a complex process involving raw materials, cellars, distillation and blending, which will affect the content and types of aromatic substances such as alcohol, aldehydes, acids and esters in Luzhou-flavor liquor. When different Luzhou-flavor liquors are added, the fluorescence signal of the sensor array will be different. The fluorescence spectra of 19 kinds of Luzhou-flavor liquors after reacting with three kinds of Ln-MOF are shown in the figure below. Figure 2 As shown, (A) is Eu-MOF@Eu-MOF; (B) is Tb-MOF@Tb-MOF; (C) is Eu-MOF@Tb-MOF. Figure 2 It can be seen that the sensor material based on the lanthanide metal organic framework of the present invention can effectively identify and distinguish Luzhou-flavor liquor.

[0042] In order to evaluate the recognition effect of the sensor array on Luzhou-flavor liquor, PCA, HCA and LDA were used for pattern recognition analysis. The results are shown in the figure. Figure 3 The PCA analysis results are shown in Figure 3 As shown in (A), it can be seen that each Luzhou-flavor liquor forms an independent cluster, parallel samples are close to each other, and different Luzhou-flavor liquors are far away from each other, without overlap or misclassification. Figure 3As shown in (B), 19 kinds of Luzhou-flavor liquors are divided into 19 groups, and three parallel samples of the same Luzhou-flavor liquor are preferentially classified into one group, without misclassification. The analysis results of LDA are consistent with those of HCA. The 19 kinds of Luzhou-flavor liquors are scattered in different areas, such as Figure 3 As shown in (C), 19 obvious clusters were formed, and the recognition accuracy reached 100%. PCA, HCA and LDA did not show any misclassification, and the fluorescence sensing array had excellent detection ability for Luzhou-flavor liquor samples.

Claims

1. Sensor materials based on lanthanide metal organic frameworks, characterized by: The sensor material is a composite material modified by adding lanthanide metal terbium or europium to a metal organic framework; the sensor material is specifically Eu-MOF@Eu-MOF, Tb-MOF@Tb-MOF or Eu-MOF@Tb-MOF material.

2. The method for preparing the sensor material based on the lanthanide metal organic framework according to claim 1, characterized in that: The steps include: (1) Synthesizing Eu-MOF or Tb-MOF materials by hydrothermal method; (2) Based on Eu-MOF or Tb-MOF materials, a hydrothermal method is used to in situ synthesize Eu-MOF@Eu-MOF, Tb-MOF@Tb-MOF or Eu-MOF@Tb-MOF materials.

3. The method for preparing a sensor material based on a lanthanide metal organic framework according to claim 2, characterized in that: In step (1) or (2), the specific synthesis method is: after the synthesis raw materials and terephthalic acid are dissolved in DMF solution, they are placed in a hydrothermal synthesis reactor for reaction, and then cooled to room temperature, washed, and vacuum dried.

4. The method for preparing a sensor material based on a lanthanide metal organic framework according to claim 3, characterized in that: At least one of the following is met: The reaction temperature is 120°C and the reaction time is 12h; Wash with DMF and first-grade water three times respectively; The vacuum drying temperature was 60°C and the time was 12 h.

5. The method for preparing a sensor material based on a lanthanide metal organic framework according to claim 3, characterized in that: In step (1), the raw material for synthesizing the Eu-MOF material is europium nitrate hexahydrate; the raw material for synthesizing the Tb-MOF material is terbium nitrate hexahydrate.

6. The method for preparing a sensor material based on a lanthanide metal organic framework according to claim 3, characterized in that: In step (2), the raw materials for the synthesis of Eu-MOF@Eu-MOF material are europium nitrate hexahydrate and Eu-MOF material; the raw materials for the synthesis of Tb-MOF@Tb-MOF material are terbium nitrate hexahydrate and Tb-MOF material; the raw materials for the synthesis of Eu-MOF@Tb-MOF material are europium nitrate hexahydrate and Tb-MOF material.

7. The preparation method according to any one of claims 3 to 4, characterized in that: Europium nitrate hexahydrate is 0.535 g; terbium nitrate hexahydrate is 0.435 g; Eu-MOF material is 0.1 g; Tb-MOF material is 0.1 g; terephthalic acid is 0.1 g; DMF solution is 30 mL of DMF + 15 mL of primary water.

8. The use of the lanthanide metal organic framework based sensor material according to claim 1, or the lanthanide metal organic framework based sensor material prepared by the preparation method according to any one of claims 2 to 7, characterized in that: A fluorescence sensing array with 11 sensing channels was constructed using Eu-MOF@Eu-MOF, Tb-MOF@Tb-MOF or Eu-MOF@Tb-MOF materials as probes to detect organic matter and Luzhou-flavor liquor.

9. The use of the sensor material based on lanthanide metal organic framework according to claim 8, characterized in that: The specific method for detecting organic matter is: using 50% ethanol as a solvent, adding Eu-MOF@Eu-MOF, Tb-MOF@Tb-MOF or Eu-MOF@Tb-MOF materials respectively, and then adding the organic matter to be tested at a concentration of 250μM for reaction, and testing the fluorescence intensity after the reaction.

10. The use of the sensor material based on lanthanide metal organic framework according to claim 8, characterized in that: The specific method for detecting Luzhou-flavor liquor is as follows: using 50% ethanol as the solvent, adding Eu-MOF@Eu-MOF, Tb-MOF@Tb-MOF or Eu-MOF@Tb-MOF materials respectively, and then adding the Luzhou-flavor liquor sample to be tested for reaction, and testing the fluorescence intensity after the reaction.

Images