A method for detecting organic cyanide using an inverse opal thin film

Abstract

The present invention belongs to the field of detection technology and relates to a method for detecting organic cyanides by using an inverse opal thin film, which comprises the following steps: Step 1, put the inverse opal thin film into an alkaline solution, observe the photonic crystal reflection peak and its color after equilibrium and stability are achieved, and obtain an inverse opal photonic crystal system; Step 2, oscillate and mix the organic cyanide solution and the nitrile hydratase solution to obtain a mixed solution; put the mixed solution into the inverse opal photonic crystal system, and realize the detection of organic cyanides by observing the color change of the inverse opal photonic crystal system and the movement of the photonic crystal reflection peak. The method for realizing the visual detection of organic cyanides by combining the inverse opal thin film with the enzymatic catalytic reaction breaks through the barriers of poor portability, complex operation and inability to perform on-site analysis of traditional detection technologies. This method is easy to operate, highly portable, highly sensitive, capable of naked-eye observation, and the lowest detection limit can reach 2×10<supgt;‑8< / supgt; g / L.

Description

Technical Field

[0001] The present invention belongs to the technical field of detection, and particularly relates to a method for detecting organic cyanides by using an inverse opal thin film. Background Art

[0002] Cyanides are important chemical raw materials, widely used in industries such as pharmaceuticals, textiles, rubber and metal smelting, plastic products, etc. They are mainly divided into inorganic cyanides and organic cyanides (or nitriles). When inhaled by organisms, cyanide ions (CN-) will be rapidly released during the in-vivo metabolic process, causing acute poisoning and having strong toxicological properties. At the same time, most nitriles can also cause obvious irritation to human mucous membranes, skin, central nervous system, etc. Animal experiments have proved that long-term exposure to such compounds has teratogenic and carcinogenic effects.

[0003] Some food-use AS and ABS plastic tableware have the phenomenon of excessive acrylonitrile monomer content. The inflow of this compound into the human body through tableware will cause symptoms such as nausea, fatigue, confusion, and numbness in hands and feet. If such tableware is used for a long time, it will cause great harm to human life and health. Therefore, it is of great practical significance to develop a method for efficiently, simply, and visually detecting nitriles.

[0004] In recent years, relatively mature methods for detecting nitriles include gas chromatography, ion chromatography, capillary electrophoresis chromatography, atomic absorption spectrometry, spectrophotometry, Raman spectrometry, ion-selective electrode method, nuclear magnetic resonance analysis method. Although these methods all have their different advantages, such as chromatography can not only determine simple cyano compounds but also complex cyano compounds, nuclear magnetic resonance analysis method has high accuracy, and spectrometry has strong stability, etc., these methods also have many deficiencies. For example, they require specialized personnel for operation, large-scale instruments are expensive and have slow response speed, poor anti-interference ability, etc. It is precisely due to the existence of these adverse factors that limit the on-site analysis of organic cyanides.

[0005] Therefore, it is of great significance to establish a technology for visually, highly sensitively, and generally detecting nitriles in detection without relying on large-scale analytical instruments and specialized personnel for operation. Summary of the Invention

[0006] The purpose of the present invention is to provide a method for detecting organic cyanides by using an inverse opal thin film, which solves the problem that the existing detection of nitriles requires reliance on instruments and specialized personnel for detection.

[0007] The present invention is realized through the following technical solutions:

[0008] A method for detecting organic cyanides by using an inverse opal thin film, comprising the following steps:

[0009] Step 1: Place the inverse opal thin film in an alkaline solution. After reaching equilibrium and stability, observe the photonic crystal reflection peak and its color to obtain the inverse opal photonic crystal system.

[0010] Step 2: Oscillate and mix the organic cyanide solution and the nitrile hydratase solution to obtain a mixed solution.

[0011] Put the mixed solution into the inverse opal photonic crystal system. By observing the color change of the inverse opal photonic crystal system and the movement of the photonic crystal reflection peak, the detection of organic cyanides is realized.

[0012] Furthermore, in Step 1, the alkaline solution is a sodium carbonate solution with a mass fraction of 5% or a sodium bicarbonate solution with a mass fraction of 5%.

[0013] Furthermore, in Step 2, the organic cyanide solution is benzonitrile, acetonitrile, adiponitrile or acrylonitrile.

[0014] Furthermore, in Step 2, the concentration of the organic cyanide is 2×10 -6 g / L - 2×10 -8 g / L, and the concentration of the nitrile hydratase is 1 g / L - 5 g / L.

[0015] Furthermore, in Step 1, the preparation method of the inverse opal thin film includes the following steps:

[0016] 1.1. Mix the functional monomer, crosslinking agent and photoinitiator in a solvent to form a copolymer system, then perform ultrasonic treatment and mix evenly to obtain a precursor solution, and store it refrigerated for later use.

[0017] 1.2. Tilt the photonic crystal thin film, then drop the precursor solution from the edge of the photonic crystal thin film to ensure complete infiltration. Then cover the upper and lower surfaces of the photonic crystal thin film with organic glass sheets to form an organic glass sheet - photonic crystal thin film - organic glass sheet sandwich structure. Cure it under ultraviolet light to make it fully polymerize. Finally, place the cured copolymer photonic crystal template in a hydrofluoric acid solution for etching to obtain the inverse opal thin film.

[0018] Furthermore, in Step 1.1, the molar ratio of the functional monomer, crosslinking agent, solvent, and photoinitiator is 5:(0.2 - 1):5:0.2.

[0019] Furthermore, in Step 1.2, the photonic crystal ordered unit of the photonic crystal thin film is silica colloidal particles.

[0020] Furthermore, in Step 1.1, the functional monomer is methacrylic acid or acrylic acid.

[0021] Furthermore, in Step 1.1, the crosslinking agent is ethylene glycol dimethacrylate or N,N - methylenebisacrylamide.

[0022] Further, in Step 1.1, the solvent is absolute ethanol;

[0023] The photoinitiator is 2-hydroxy-2-methylpropiophenone.

[0024] Compared with the prior art, the present invention has the following beneficial technical effects:

[0025] The present invention discloses a method for detecting organic cyanides using an inverse opal thin film. First, an inverse opal photonic crystal sensor with pH responsiveness is prepared. Since the hydrolysis of nitriles requires an alkaline condition, the inverse opal photonic crystal sensor is first placed in an alkaline solution, and after it stabilizes, its photonic crystal reflection peak is observed. When nitrile hydratase and the test solution are added, the nitrile hydratase reacts with the cyanide to generate carboxylic acid, the pH decreases, and the reflection peak of the inverse opal photonic crystal blue-shifts. Macroscopically, the photonic crystal shows a color change. Therefore, the photonic crystal sensor prepared by the present invention indirectly realizes the visual detection of cyanides by detecting the pH change generated by the catalytic action of cyanides and nitrile hydratase. Compared with traditional gas chromatography, ultraviolet-spectrophotometry, nuclear magnetic resonance analysis, and surface-enhanced Raman spectroscopy, the present invention does not require specialized personnel for operation, is simple to operate, has high sensitivity, fast response speed, is inexpensive and portable, and can perform on-site real-time visual detection without relying on other large instruments. The lowest detection limit can reach 2×10 -8 g / L. Description of the Drawings

[0026] Figure 1 is the reflection spectrum diagram of the photonic crystal sensor of Example 1 of the present invention before and after equilibration with a mixed solution of 2×10 -6 g / L benzonitrile and 1 g / L nitrile hydratase.

[0027] Figure 2 is the reflection spectrum diagram of the photonic crystal sensor of Example 2 of the present invention before and after equilibration with a mixed solution of 2×10 -7 g / L benzonitrile and 1 g / L nitrile hydratase.

[0028] Figure 3 is the reflection spectrum diagram of the photonic crystal sensor of Example 3 of the present invention before and after equilibration with a mixed solution of 2×10 -8 g / L benzonitrile and 1 g / L nitrile hydratase.

[0029] Figure 4 is the reflection spectrum diagram of the photonic crystal sensor of Example 4 of the present invention before and after equilibration with a mixed solution of 2×10 -7 g / L acetonitrile and 1 g / L nitrile hydratase.

[0030] Figure 5 is the reflection spectrum diagram of the photonic crystal sensor of Example 5 of the present invention before and after equilibration with 2×10 -7Reflection spectra of the mixed solution of 1 g / L acrylonitrile and 1 g / L nitrile hydratase before and after equilibrium.

[0031] Figure 6 For Example 6 of the present invention, it is the reflection spectra of the photonic crystal sensor before and after equilibrium when adding the mixed solution of 2×10 -7 g / L adiponitrile and 1 g / L nitrile hydratase.

[0032] Figure 7 For Example 7 of the present invention, it is the reflection spectra of the photonic crystal sensor before and after equilibrium when adding the mixed solution of 2×10 -7 g / L adiponitrile and 5 g / L nitrile hydratase.

[0033] Figure 8 For Example 8 of the present invention, it is the reflection spectra of the photonic crystal sensor before and after equilibrium when only adding 1 g / L nitrile hydratase solution.

[0034] Figure 9 For Example 9 of the present invention, it is the reflection spectra of the photonic crystal sensor system before and after equilibrium when adding the mixed solution of 2×10 -7 g / L acrylonitrile and 1 g / L nitrile hydratase as well as the interference ion solutions of NaNO3 and KNO3. Detailed implementation manners

[0035] In order to make the objectives, technical solutions and advantages of the present invention clearer and more understandable, the following further detailed description is provided in conjunction with the drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not used to limit the present invention, that is, the described embodiments are only a part of the embodiments of the present invention, rather than all embodiments.

[0036] The components described and shown in the drawings and embodiments of the present invention can be arranged and designed in various different configurations. Therefore, the detailed description of the embodiments of the present invention provided in the following drawings is not intended to limit the scope of the claimed invention, but only represents a selected embodiment of the present invention. Based on the drawings and embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative efforts fall within the protection scope of the present invention.

[0037] It should be noted that: the term "comprising", "including" or any other variant thereof is intended to cover non-exclusive inclusion, so that a process, element, method, article or device including a series of elements not only includes those elements, but also includes other elements not expressly listed, or also includes elements inherent to the process, element, method, article or device.

[0038] The present invention provides a method for visual detection of organic cyanides by combining photonic crystals and enzymatic catalytic reactions. The specific steps are as follows:

[0039] Step 1: Prepare an alkaline solution with a certain concentration. Place the inverse opal film in this solution and observe the photonic crystal reflection peak and its color after equilibrium and stabilization to obtain an inverse opal photonic crystal system.

[0040] Step 2: Shake different organic cyanide solutions and nitrilase solutions well, and then place the mixed solution into the inverse opal photonic crystal system. By observing the color change of the film and the shift of the photonic crystal reflection peak, the detection of organic cyanides is achieved.

[0041] The preparation method of the inverse opal film includes the following steps:

[0042] 1.1 Prepare the precursor solution: Mix the functional monomer, cross-linking agent, and photoinitiator in a certain proportion in an ethanol solvent to form a copolymer system, and then ultrasonically treat it to make the mixture uniform and refrigerate for later use.

[0043] 1.2 Then tilt the photonic crystal film at a certain angle, and drop the precursor solution obtained in Step 1 from the edge of the film to ensure complete infiltration. Then cover the same-sized plexiglass sheet on its surface to form a plexiglass sheet - photonic crystal film - plexiglass sheet sandwich structure, and cure it under ultraviolet light to make it fully polymerized. Finally, immerse the cured copolymer photonic crystal template in a hydrofluoric acid solution for etching to obtain the inverse opal film, and soak it in deionized water for later use.

[0044] The inverse opal film can also be called an inverse opal photonic crystal sensor. A photonic crystal is an artificial and highly ordered material with a dielectric constant that varies periodically in space. When visible light irradiates the surface of the photonic crystal, light within a certain frequency range is prohibited from propagating and is thus reflected into the human eye, and the color seen by our naked eyes is called the structural color. The existence of special optical properties endows the photonic crystal with the possibility of realizing visual detection and is used to develop various chemical sensors.

[0045] As one of the important industrial enzymes, nitrilase can directly catalyze the hydrolysis of nitrile compounds under alkaline conditions to directly generate the corresponding carboxylic acid and ammonia in one step. In addition, the pH-responsive hydrogel photonic crystal can respond to acidic or alkaline ions within a short time, showing an obvious color change macroscopically. Therefore, through the response of the photonic crystal sensor to pH, the on-site visual detection of nitriles can be indirectly realized.

[0046] The ordered unit of the photonic crystal is silica colloidal particles.

[0047] The functional monomer is methacrylic acid or acrylic acid; the cross-linking agent is ethylene glycol dimethacrylate or N,N'-methylenebisacrylamide; the solvent used is anhydrous ethanol; the photoinitiator used is 2-hydroxy-2-methylpropiophenone.

[0048] The alkaline solution is a sodium carbonate or sodium bicarbonate solution; the concentration is a 5% by mass fraction of the above solution.

[0049] The molar ratio of the functional monomer, crosslinking agent, solvent, and photoinitiator is 5:(0.2 - 1):5:0.2.

[0050] The different organic cyanide solutions are benzonitrile, acetonitrile, adiponitrile, and acrylonitrile. The concentration of the organic cyanide is 2×10 -6 g / L - 2×10 -8 g / L, and the concentration of nitrile hydratase is 1 g / L - 5 g / L.

[0051] The features and properties of the present invention are further described in detail below in conjunction with the embodiments.

[0052] Example 1

[0053] The experimental steps for detecting a 2x10 -6 g / L benzonitrile solution are as follows:

[0054] Step 1: Using methacrylic acid as the functional monomer, ethylene glycol dimethacrylate as the crosslinking agent, ethanol as the solvent, and dihydroxydimethylbenzophenone as the photoinitiator, prepare a precursor solution according to a molar ratio of 5: 0.2 : 5:0.2, place it in an ultrasonic cleaner for 60 min to mix it evenly, and then put it in the refrigerator for storage for later use.

[0055] Step 2: Then tilt the photonic crystal film by 15°, and then drop the precursor solution obtained in Step 1 from the edge of the inverse opal film. Use capillary force to ensure its complete penetration, and then cover the same-sized plexiglass sheet on its surface to form a plexiglass sheet - photonic crystal film - plexiglass sheet sandwich structure. Cure it under ultraviolet light for 3 - 5 h to make it fully polymerize. Finally, place the cured copolymer photonic crystal template in a 1% hydrofluoric acid solution for etching to obtain the inverse opal film, and soak it in deionized water for later use.

[0056] Step 3: Prepare a 5% by mass fraction sodium carbonate solution, put the inverse opal template into this solution, and after equilibrium and stability, observe the reflection peak and color of the photonic crystal. The reflection peak moved from the initial 540 nm to 712 nm, and the color also changed from green to dark red.

[0057] Step 4: Add 2 mL of a 2×10 -5 g / L benzonitrile solution to 500 μL of a 1 g / L nitrile hydratase solution. After fully shaking it evenly, drop it into a 7.5 mL 5% by mass fraction sodium carbonate solution and inverse opal film system, observe the color change of the sensor, and record the reflection spectrum of the inverse opal film before and after adding the benzonitrile and nitrile hydratase mixed solution through a spectrometer.

[0058] Conclusion: When the inverse opal photonic crystal sensor detects a 2×10 -6 g / L benzonitrile solution, due to the catalytic hydrolysis reaction between benzonitrile and nitrile hydrolase, the pH change in the original alkaline system becomes smaller. From Figure 1 it can be observed that the reflection peak of the sensor moves from the initial 712 nm to 616 nm, with a total movement of 96 nm. The color of the film at equilibrium also changes from dark red to yellow. Therefore, the visual detection of a 2×10 -6 g / L benzonitrile solution can be achieved.

[0059] Example 2

[0060] The experimental steps for detecting a 2x10 -7 g / L benzonitrile solution are as follows:

[0061] Step 1: Using methacrylic acid as the functional monomer, ethylene glycol dimethacrylate as the crosslinking agent, ethanol as the solvent, and dihydroxydimethylbenzophenone as the photoinitiator, prepare a precursor solution according to a molar ratio of 5:0.4:5:0.2. Put it into an ultrasonic cleaner for 60 min to mix it evenly, and then put it in the refrigerator for later use.

[0062] Step 2: Then tilt the photonic crystal film by 15°. Then, drop the precursor solution obtained in Step 1 from the edge of the inverse opal film and ensure its complete penetration using capillary force. Then, cover the same-sized plexiglass sheet on its surface to form a plexiglass sheet - photonic crystal film - plexiglass sheet sandwich structure. Cure it under ultraviolet light for 3 - 5 h to fully polymerize it. Finally, immerse the cured copolymer photonic crystal template in a 1% hydrofluoric acid solution for etching to obtain the inverse opal film, and soak it in deionized water for later use.

[0063] Step 3: Prepare a sodium carbonate solution with a mass fraction of 5%. After putting the inverse opal template into this solution and waiting for equilibrium and stability, observe the reflection peak and color of the photonic crystal. The reflection peak moves from the initial 540 nm to 712 nm, and the color also changes from green to dark red.

[0064] Step 4: Add 2 mL of a 2×10 -6 g / L benzonitrile solution to 500 μL of a 1 g / L nitrile hydrolase solution. After fully shaking it evenly, drop it into a 7.5 mL sodium carbonate solution with a mass fraction of 5% and the inverse opal film system. Observe the color change of the sensor and record the reflection spectrum of the inverse opal film before and after adding the benzonitrile and nitrile hydrolase mixed solution using a spectrometer.

[0065] Conclusion: When the inverse opal photonic crystal sensor detects a 2×10 -7When in a benzene nitrile solution of g / L, due to the catalytic hydrolysis reaction between benzene nitrile and nitrile hydrolase, the pH change of the original alkaline system becomes smaller. From Figure 2 It can be observed that the reflection peak of the sensor moves from the initial 712 nm to 623 nm, a total movement of 89 nm. At equilibrium, the color of the film also changes from dark red to orange. Therefore, visual detection of a 2×10 -7 benzene nitrile solution can be achieved.

[0066] Example 3

[0067] To detect a 2×10 -8 benzene nitrile solution, the experimental steps are as follows:

[0068] Step 1: Using methacrylic acid as the functional monomer, N,N-methylenebisacrylamide as the crosslinking agent, ethanol as the solvent, and dihydroxydimethylbenzophenone as the photoinitiator, prepare a precursor solution according to a molar ratio of 5:0.4:5:0.2. Place it in an ultrasonic cleaner for 60 min to mix evenly, and then refrigerate it for later use.

[0069] Step 2: Then tilt the photonic crystal film by 15°. Drop the precursor solution obtained in Step 1 from the edge of the inverse opal film, and use capillary force to ensure its complete penetration. Then cover the same-sized plexiglass sheet on its surface to form a plexiglass sheet-photonic crystal film-plexiglass sheet sandwich structure. Cure it under ultraviolet light for 3 - 5 h to fully polymerize. Finally, immerse the cured copolymer photonic crystal template in a 1% hydrofluoric acid solution for etching to obtain the inverse opal film, and soak it in deionized water for later use.

[0070] Step 3: Prepare a sodium carbonate solution with a mass fraction of 5%. Place the inverse opal template in this solution. After equilibrium and stability, observe the reflection peak and color of the photonic crystal. The reflection peak moves from the initial 540 nm to 712 nm, and the color also changes from green to dark red.

[0071] Step 4: Add 2 mL of a benzene nitrile solution with a concentration of 2×10 -7 g / L to 500 μL of a nitrile hydrolase solution with a concentration of 1 g / L. After shaking well, drop it into a system of 7.5 mL of a sodium carbonate solution with a mass fraction of 5% and the inverse opal film. Observe the color change of the sensor and record the reflection spectrum of the inverse opal film before and after adding the benzene nitrile and nitrile hydrolase mixed solution through a spectrometer.

[0072] Conclusion: When the inverse opal photonic crystal sensor detects a 2×10 -8 benzene nitrile solution, due to the catalytic hydrolysis reaction between benzene nitrile and nitrile hydrolase, the pH change of the original alkaline system becomes smaller. From Figure 3It can be observed that the reflection peak of the sensor has shifted from the initial 712 nm to 631 nm, with a total shift of 81 nm. The color of the film at equilibrium has also changed from dark red to light red. Therefore, visual detection of 2×10 -8 g / L benzonitrile solution can be achieved.

[0073] Example 4

[0074] The experimental steps for detecting 2×10 -7 g / L acetonitrile solution are as follows:

[0075] Step 1: Prepare a precursor solution by mixing acrylic acid as the functional monomer, ethylene glycol dimethacrylate as the crosslinking agent, ethanol as the solvent, and dihydroxydimethylbenzophenone as the photoinitiator in a molar ratio of 5:0.2:5:0.2. Place it in an ultrasonic cleaner for 60 min to mix evenly, and then refrigerate it for later use.

[0076] Step 2: Then tilt the photonic crystal film by 15°. Drop the precursor solution obtained in Step 1 from the edge of the inverse opal film and ensure its complete infiltration using capillary force. Then cover the surface with an organic glass sheet of the same size to form a sandwich structure of organic glass sheet - photonic crystal film - organic glass sheet. Cure it under ultraviolet light for 3 - 5 h to allow full polymerization. Finally, immerse the cured copolymer photonic crystal template in a 1% hydrofluoric acid solution for etching to obtain the inverse opal film, and soak it in deionized water for later use.

[0077] Step 3: Prepare a sodium bicarbonate solution with a mass fraction of 5%. Place the inverse opal template in this solution and observe the reflection peak and color of the photonic crystal after equilibrium is reached. The reflection peak has shifted from the initial 540 nm to 712 nm, and the color has changed from green to dark red.

[0078] Step 4: Add 2 mL of acetonitrile solution with a concentration of 2×10 -6 g / L to 500 μL of nitrile hydratase solution with a concentration of 1 g / L. After shaking well, drop it into a system of 7.5 mL of sodium bicarbonate solution with a mass fraction of 5% and the inverse opal film. Observe the color change of the sensor and record the reflection spectra of the inverse opal film before and after adding the acetonitrile and nitrile hydratase mixed solution using a spectrometer.

[0079] Conclusion: When the inverse opal photonic crystal sensor detects 2×10 -7 g / L acetonitrile solution, due to the catalytic hydrolysis reaction between acetonitrile and nitrile hydratase, the pH change in the original alkaline system becomes smaller. From Figure 4It can be observed that the reflection peak of the sensor has shifted from the initial 712 nm to 649 nm, with a total shift of 63 nm. The color of the film at equilibrium has also changed from dark red to red, so it is possible to achieve visual detection of 2×10 -7 g / L acetonitrile solution.

[0080] Example 5

[0081] Detection of 2x10 -7 The experimental procedure for detecting g / L acrylonitrile solution is as follows:

[0082] Step 1: Using acrylic acid as the functional monomer, N,N-methylenebisacrylamide as the crosslinking agent, ethanol as the solvent, and dihydroxydimethylbenzophenone as the photoinitiator, prepare a precursor solution according to a molar ratio of 5:0.6:5:0.2. Place it in an ultrasonic cleaner for 60 min to mix it evenly, and then refrigerate it for later use.

[0083] Step 2: Then tilt the photonic crystal film by 15°, and drop the precursor solution obtained in Step 1 from the edge of the inverse opal film. Use capillary force to ensure its complete infiltration, and then cover the same-sized plexiglass sheet on its surface to form a plexiglass sheet-photonic crystal film-plexiglass sheet sandwich structure. Cure it under ultraviolet light for 3-5 h to fully polymerize it. Finally, place the cured copolymer photonic crystal template in a 1% hydrofluoric acid solution for etching to obtain the inverse opal film, and soak it in deionized water for later use.

[0084] Step 3: Prepare a sodium carbonate solution with a mass fraction of 5%. After placing the inverse opal template in this solution and waiting for equilibrium and stability, observe the reflection peak and color of the photonic crystal. The reflection peak has shifted from the initial 540 nm to 712 nm, and the color has also changed from green to dark red.

[0085] Step 4: Add 2 mL of acrylonitrile solution with a concentration of 2×10 -6 g / L to 500 μL of nitrile hydratase solution with a concentration of 1 g / L. After shaking it well, drop it into a system of 7.5 mL of sodium carbonate solution with a mass fraction of 5% and the inverse opal film. Observe the color change of the sensor and record the reflection spectra of the inverse opal film before and after adding the acrylonitrile and nitrile hydratase mixed solution through a spectrometer.

[0086] Conclusion: When the inverse opal photonic crystal sensor detects 2×10 -7 g / L acrylonitrile solution, due to the catalytic hydrolysis reaction between acrylonitrile and nitrile hydratase, the pH change of the original alkaline system becomes smaller, from Figure 5It can be observed that the reflection peak of the sensor has shifted from the initial 712 nm to 655 nm, a total shift of 57 nm. The color of the film at equilibrium has also changed from dark red to red, so the visual detection of 2×10 -7 g / L acrylonitrile solution can be achieved.

[0087] Example 6

[0088] The experimental steps for detecting 2×10 -7 g / L adiponitrile solution are as follows:

[0089] Step 1: Using methacrylic acid as the functional monomer, ethylene glycol dimethacrylate as the crosslinking agent, ethanol as the solvent, and dihydroxydimethylbenzophenone as the photoinitiator, prepare a precursor solution according to a molar ratio of 5:0.8:5:0.2, put it into an ultrasonic cleaner for 60 min to mix evenly, and then put it in the refrigerator for later use.

[0090] Step 2: Then tilt the photonic crystal film by 15°, and then drop the precursor solution obtained in Step 1 from the edge of the inverse opal film. Use capillary force to ensure its complete infiltration, and then cover the same-sized plexiglass sheet on its surface to form a plexiglass sheet - photonic crystal film - plexiglass sheet sandwich structure. Cure it under ultraviolet light for 3 - 5 h to fully polymerize. Finally, place the cured copolymer photonic crystal template in a 1% hydrofluoric acid solution for etching to obtain the inverse opal film, and soak it in deionized water for later use.

[0091] Step 3: Prepare a sodium carbonate solution with a mass fraction of 5%. After putting the inverse opal template into this solution and waiting for equilibrium and stability, observe the reflection peak and color of the photonic crystal. The reflection peak has shifted from the initial 540 nm to 712 nm, and the color has also changed from green to dark red.

[0092] Step 4: Add 2 mL of 2×10 -6 g / L adiponitrile solution to 500 μL of 1 g / L nitrile hydratase solution. After shaking well, drop it into a system of 7.5 mL of 5% sodium carbonate solution and the inverse opal film. Observe the color change of the sensor and record the reflection spectrum of the inverse opal film before and after adding the adiponitrile and nitrile hydratase mixed solution through a spectrometer.

[0093] Conclusion: When the inverse opal photonic crystal sensor detects 2x10 -7 g / L adiponitrile solution, due to the catalytic hydrolysis reaction between adiponitrile and nitrile hydratase, the pH change of the original alkaline system becomes smaller, from Figure 6It can be observed that the reflection peak of the sensor has shifted from the initial 712 nm to 545 nm, a total shift of 167 nm. The color of the film at equilibrium has also changed from dark red to green, thus enabling the visual detection of 2×10 -7 g / L adiponitrile solution.

[0094] Example 7

[0095] The experimental procedure for detecting 2×10 -7 g / L adiponitrile solution by changing the concentration of nitrile hydratase to 5 g / L is as follows:

[0096] Step 1: Using methacrylic acid as the functional monomer, ethylene glycol dimethacrylate as the crosslinking agent, ethanol as the solvent, and dihydroxydimethylbenzophenone as the photoinitiator, prepare a precursor solution according to a molar ratio of 5:0.8:5:0.2. Place it in an ultrasonic cleaner for 60 min to mix it evenly, and then refrigerate it for later use.

[0097] Step 2: Then tilt the photonic crystal film by 15°. Drop the precursor solution obtained in Step 1 from the edge of the inverse opal film, and use capillary force to ensure its complete penetration. Then cover the same-sized plexiglass sheet on its surface to form a plexiglass sheet - photonic crystal film - plexiglass sheet sandwich structure. Cure it under ultraviolet light for 3 - 5 h to make it fully polymerize. Finally, place the cured copolymer photonic crystal template in a 1% hydrofluoric acid solution for etching to obtain the inverse opal film, and soak it in deionized water for later use.

[0098] Step 3: Prepare a sodium bicarbonate solution with a mass fraction of 5%. After placing the inverse opal template in this solution and waiting for equilibrium and stability, observe the reflection peak and color of the photonic crystal. The reflection peak has shifted from the initial 540 nm to 712 nm, and the color has also changed from green to dark red.

[0099] Step 4: Add 2 mL of 2×10 -6 g / L adiponitrile solution to 500 μL of 5 g / L nitrile hydratase solution. After shaking it well, drop it into a system of 7.5 mL of 5% sodium bicarbonate solution and the inverse opal film. Observe the color change of the sensor and record the reflection spectra of the inverse opal film before and after adding the adiponitrile and nitrile hydratase mixed solution through a spectrometer.

[0100] Conclusion: When the inverse opal photonic crystal sensor detects 2×10 -7 g / L adiponitrile solution and changes the concentration of nitrilase to 5 g / L, due to the catalytic hydrolysis reaction between adiponitrile and nitrile hydratase, the pH change of the original alkaline system becomes smaller. Since the nitrile hydratase concentration in Example 7 is greater than that in Example 6, the color change of the film in Example 7 is faster. At the same time, byFigure 7 It can be observed that the reflection peak of the sensor still moves from the initial 712 nm to 545 nm, with a total movement of 167 nm. The color of the film at equilibrium also changes from dark red to green. Therefore, this experiment can prove that the higher the concentration of nitrilase, the faster the reaction rate, but does not change the final experimental result.

[0101] Example 8

[0102] The experimental steps for detecting a nitrile solution with a concentration of 0 g / L are as follows:

[0103] Step 1: Prepare a precursor solution by mixing methacrylic acid as the functional monomer, ethylene glycol dimethacrylate as the crosslinking agent, ethanol as the solvent, and dihydroxydimethylbenzophenone as the photoinitiator in a molar ratio of 5:1:5:0.2. Place it in an ultrasonic cleaner for 60 min to mix evenly, and then refrigerate it for later use.

[0104] Step 2: Then tilt the photonic crystal film by 15°. Drop the precursor solution obtained in Step 1 from the edge of the inverse opal film and ensure its complete infiltration using capillary force. Then cover the surface with an organic glass sheet of the same size to form a sandwich structure of organic glass sheet - photonic crystal film - organic glass sheet. Cure it under ultraviolet light for 3 - 5 h to fully polymerize. Finally, immerse the cured copolymer photonic crystal template in a 1% hydrofluoric acid solution for etching to obtain the inverse opal film, and soak it in deionized water for later use.

[0105] Step 3: Prepare a sodium carbonate solution with a mass fraction of 5%. Place the inverse opal template in this solution and observe the reflection peak and color of the photonic crystal after equilibrium is reached. The reflection peak moves from the initial 540 nm to 712 nm, and the color also changes from green to dark red.

[0106] Step 4: Drop 200 μL of a 5 g / L nitrilase solution into a system of 7.5 mL of a 5% sodium carbonate solution and the inverse opal film. Observe the color change of the sensor and record the reflection spectrum of the inverse opal film before and after adding the nitrilase mixed solution using a spectrometer.

[0107] Conclusion: When only nitrilase is added to the inverse opal photonic crystal sensor, Figure 8 It can be observed that the reflection peak of the sensor moves from the initial 712 nm to 708 nm, with a total movement of 4 nm. The color of the film at equilibrium remains dark red. Therefore, it can be proved that the system is very stable and does not change color without adding nitriles.

[0108] Example 9

[0109] Based on Example 5, the experimental steps for detecting the stability of the photonic crystal sensor are as follows:

[0110] Step 1: Using methacrylic acid as the functional monomer, N,N-methylenebisacrylamide as the crosslinking agent, ethanol as the solvent, and dihydroxydimethylbenzophenone as the photoinitiator, prepare a precursor solution according to a molar ratio of 5:0.6:5:0.2. Place it in an ultrasonic cleaner for 60 min to mix evenly, and then refrigerate it for later use.

[0111] Step 2: Then tilt the photonic crystal film by 15°. Drop the precursor solution obtained in Step 1 from the edge of the inverse opal film, and ensure its complete infiltration using capillary force. Then cover the surface with an organic glass sheet of the same size to form a sandwich structure of organic glass sheet-photonic crystal film-organic glass sheet. Cure it under ultraviolet light for 3 - 5 h to allow full polymerization. Finally, immerse the cured copolymer photonic crystal template in a 1% hydrofluoric acid solution for etching to obtain the inverse opal film, and soak it in deionized water for later use.

[0112] Step 3: Prepare a sodium carbonate solution with a mass fraction of 5%. Place the inverse opal template in this solution and wait for it to reach equilibrium and stability. Observe the reflection peak and color of the photonic crystal. The reflection peak moves from the initial 540 nm to 712 nm, and the color changes from green to dark red.

[0113] Step 4: Add 2 mL of acrylonitrile solution with a concentration of 2×10 -6 g / L to 500 μL of nitrile hydratase solution with a concentration of 5 g / L. After shaking well, drop it into a system of 7.5 mL of sodium carbonate solution with a mass fraction of 10% and the inverse opal film. Then add a few drops of interference solutions of 5% KNO3 and NaNO3. Observe the color change of the sensor and record the reflection spectra of the inverse opal film before and after adding the acrylonitrile and nitrile hydratase mixed solution and the interference solutions using a spectrometer.

[0114] Conclusion: After adding the interference solution to the acrylonitrile-nitrile hydratase inverse opal photonic crystal sensor system, Figure 9 it can be observed that the reflection peak of the sensor moves from the initial 712 nm to 655 nm, a total movement of 57 nm. Compared with Figure 5 which remains unchanged, the color of the film remains red at equilibrium. Therefore, it can be proved that the photonic crystal sensor has strong anti-interference ability and is not easily affected by other external solutions.

[0115] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and are not intended to limit them. Although the present invention has been described in detail with reference to the above embodiments, those of ordinary skill in the art should understand that: it is still possible to modify the specific implementation manners of the present invention or make equivalent substitutions, and any modification or equivalent substitution that does not depart from the spirit and scope of the present invention shall be covered by the protection scope of the claims of the present invention.

Claims

1. A method for detecting organic cyanide using an inverse opal thin film, characterized in that, It includes the following steps: Step 1: Place the inverse opal film in an alkaline solution. After reaching equilibrium and stability, observe the photonic crystal reflection peak and its color to obtain the inverse opal photonic crystal system. Step 2: Oscillate and mix the organic cyanide solution and the nitrile hydratase solution to obtain a mixed solution. Put the mixed solution into the inverse opal photonic crystal system. By observing the color change of the inverse opal photonic crystal system and the movement of the photonic crystal reflection peak, the detection of organic cyanides is achieved.

2. The method for detecting organic cyanide using an inverse opal thin film according to claim 1, wherein, In Step 1, the alkaline solution is a sodium carbonate solution with a mass fraction of 5% or a sodium bicarbonate solution with a mass fraction of 5%.

3. A method for detecting organic cyanide using an inverse opal thin film according to claim 1, characterized in that, In Step 2, the organic cyanide solution is benzonitrile, acetonitrile, adiponitrile or acrylonitrile.

4. The method for detecting organic cyanide using an inverse opal thin film according to claim 1, characterized in that, In Step 2, the concentration of the organic cyanide is 2×10-6 g / L - 2×10-8 g / L, and the concentration of the nitrile hydratase is 1 g / L - 5 g / L.

5. A method for detecting organic cyanide using an inverse opal thin film according to claim 1, characterized in that, In Step 1, the preparation method of the inverse opal film includes the following steps: 1.

1. Mix the functional monomer, crosslinking agent and photoinitiator in a solvent to form a copolymer system. Then, perform ultrasonic treatment and mix evenly to obtain a precursor solution, which is refrigerated for later use. 1.

2. Tilt the photonic crystal film, and then drop the precursor solution from the edge of the photonic crystal film to ensure complete infiltration. Then, cover the upper and lower surfaces of the photonic crystal film with plexiglass sheets to form a plexiglass sheet - photonic crystal film - plexiglass sheet sandwich structure. Cure it under ultraviolet light to make it fully polymerize. Finally, place the cured copolymer photonic crystal template in a hydrofluoric acid solution for etching to obtain the inverse opal film.

6. The method for detecting organic cyanide using an inverse opal thin film according to claim 5, characterized in that, In Step 1.1, the molar ratio of the functional monomer, crosslinking agent, solvent, and photoinitiator is 5:(0.2 - 1):5:0.

2.

7. A method for detecting organic cyanide using an inverse opal thin film according to claim 5, characterized in that, In Step 1.2, the photonic crystal ordered unit of the photonic crystal film is silica colloidal particles.

8. A method for detecting organic cyanide using an inverse opal thin film according to claim 5, characterized in that, In Step 1.1, the functional monomer is methacrylic acid or acrylic acid.

9. A method for detecting organic cyanide using an inverse opal thin film according to claim 5, characterized in that, In Step 1.1, the crosslinking agent is ethylene glycol dimethacrylate or N,N'-methylenebisacrylamide.

10. A method for detecting organic cyanide using an inverse opal thin film according to claim 5, characterized in that, In Step 1.1, the solvent is anhydrous ethanol; The photoinitiator is 2-hydroxy-2-methylpropiophenone.

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