Nitro sensor based on pyrene molecule excimer and application method
By inserting the pyrene derivative solvent green 7 into the laminate of bimetallic hydroxide (LDH), SG7-LDH composite material was prepared, which solved the problem of detecting nitro compounds in liquid state, and achieved effective detection in solution state and reusable material.
Patent Information
- Application Number
- CN202510117064.8
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-01-24
- Publication Date
- 2025-05-06
AI Technical Summary
The prior art is difficult to effectively detect nitro compounds hidden in the liquid in the liquid state, and pyrene molecules are difficult to maintain an effective distance between molecules in the liquid state to form an excited group association.
The pyrene derivative solvent green 7 was inserted between the rigid layered plates of layered bimetallic hydroxide (LDH) by co-precipitation method, and the SG7-LDH composite material was prepared to achieve nitro sensing in solution.
Effective detection of nitro compounds in solution state is achieved, fluorescence quenching caused by disordered accumulation of free SG7 is avoided, and the SG7-LDH composite material is easy to recover and can be reused.
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Figure CN119935972A_ABST
Abstract
Description
Technical Field
[0001] The invention relates to the technical field of composite material preparation, and in particular to a nitro sensor based on pyrene molecule excimer and an application method thereof. Background Art
[0002] Nitro compounds are widely used in military fields and scientific research due to their explosiveness and toxicity. Therefore, many methods for detecting nitro compounds have emerged, such as biosensors, electrochemical sensors, fluorescence sensors, and other methods. Currently, fluorescence sensing, as one of the most widely used methods for detecting nitro compounds, has also been greatly developed. However, as an electron-rich material, pyrene molecules are difficult to maintain intermolecular bonding in liquid state. The effective distance of pyrene molecules to form exciplexes, therefore, the exciplexes of pyrene molecules can only exert their maximum nitro sensing effect in the solid state. It is difficult to use pyrene molecules to achieve effective sensing of nitro compounds hidden in liquids such as beverages. Therefore, the preparation of stable pyrene molecular materials is of great significance for nitro detection. Summary of the invention
[0003] The technical problem to be solved by the present invention is to provide a nitro sensor and application method based on pyrene molecular exciplex in view of the above-mentioned deficiencies in the prior art. The pyrene derivative solvent green 7 (SG7) is inserted into the rigid layers of layered double hydroxide (LDH) by coprecipitation method, and the obtained SG7-LDH composite material can be directly used for nitro sensing.
[0004] The present invention provides a nitro sensor based on pyrene molecule excimer, comprising the following steps:
[0005] S1, taking magnesium chloride solution and aluminum chloride solution and mixing them to obtain chloride salt solution;
[0006] S2. Under a nitrogen atmosphere, chloride solution and sodium hydroxide solution were added dropwise to the aqueous solution of solvent green 7, and stirred at a constant temperature to obtain Mg2Al-SG7-LDH slurry;
[0007] S3, Mg2Al-SG7-LDH slurry was centrifugally washed with distilled water and methanol, and then stored in a methanol solution to obtain a SG7-LDH composite material dispersion, namely, a nitro sensor.
[0008] According to a nitro sensor based on pyrene molecular excimer provided by the present invention, the chloride solution in S1 is obtained by uniformly mixing 100 mL of a 100 mmol / L magnesium chloride solution and 100 mL of a 50 mmol / L aluminum chloride solution, wherein the Mg in the chloride solution is 100 mmol / L. 2+ The concentration is 50mmol / L, Al 3+ The concentration is 25mmol / L.
[0009] According to a nitro sensor based on pyrene molecular excimer provided by the present invention, the concentration of the solvent green 7 aqueous solution in S2 is 15 mmol / L, the concentration of the sodium hydroxide solution is 0.1 mol / L, the volume ratio of the solvent green 7 aqueous solution, the chloride solution and the sodium hydroxide solution is 200 mL: 200 mL: 200 mL, the pH value during the constant temperature stirring process is 7.5, and the constant temperature stirring time is 6 to 8 hours.
[0010] According to a nitro sensor based on pyrene molecular exciplex provided by the present invention, the concentration of the SG7-LDH composite material in S3 is 0.1 g / L.
[0011] The present invention also provides an application method of the above-mentioned nitro sensor based on pyrene molecular excimer, comprising the following steps: dispersing the SG7-LDH composite material dispersion in a nitro-containing benzene derivative solution, mixing evenly to obtain a mixed solution, and testing the fluorescence spectrum of the mixed solution.
[0012] According to the application method of a nitro sensor based on pyrene molecular excimer provided by the present invention, the volume ratio of the SG7-LDH composite material dispersion and the nitro-containing benzene derivative solution is 0.1 mL:1.9 mL.
[0013] According to the application method of the nitro sensor based on the pyrene molecule excimer provided by the present invention, the excitation wavelength of the fluorescence spectrum of the test mixed solution is 360 nm.
[0014] Compared with the prior art, the present invention has the following advantages:
[0015] In the present invention, the pyrene derivative solvent green 7 is inserted between the rigid layers of the layered double metal hydroxide by the coprecipitation method to obtain the SG7-LDH composite material, which can be directly used for nitro sensing. Among them, the preparation of the ordered array of SG7 between the LDH layers in the SG7-LDH composite material can realize the detection of nitro compounds by pyrene molecules in the solution state, and effectively avoid the fluorescence quenching caused by the disordered accumulation of free SG7; the SG7-LDH composite material is easy to recycle and can be separated from the solution of nitrobenzene derivatives by centrifugation and can be used multiple times; at the same time, the raw materials are simple and easy to purchase, LDH is green and environmentally friendly, and can achieve good nitro sensing in organic solvents. BRIEF DESCRIPTION OF THE DRAWINGS
[0016] In order to more clearly illustrate the technical solutions in the present invention or the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.
[0017] Figure 1 It is a schematic diagram of the structure of the nitro sensor based on the pyrene molecule excimer;
[0018] Figure 2 The fluorescence excitation spectrum (a) and emission spectrum (b) of Mg2Al-SG7-LDH in Example 1;
[0019] Figure 3 is the fluorescence excitation spectrum of the SG7 methanol solution in Example 1;
[0020] Figure 4 The fluorescence quenching graph (a) and the corresponding fluorescence quenching percentage (b) of SG7-LDH on 2-NP in Example 2;
[0021] Figure 5 The fluorescence quenching graph (a) and the corresponding fluorescence quenching percentage (b) of SG7-LDH on 3-NP in Example 3;
[0022] Figure 6 is the fluorescence quenching graph (a) of SG7-LDH on NB and the corresponding fluorescence quenching percentage (b) in Example 4;
[0023] Figure 7 The fluorescence quenching graph (a) and the corresponding fluorescence quenching percentage (b) of SG7-LDH on 1,3-DNB in Example 5;
[0024] Figure 8 The fluorescence quenching graph (a) and the corresponding fluorescence quenching percentage (b) of SG7-LDH on 3,5-DNS in Example 6;
[0025] Fig. 9 The fluorescence quenching graph (a) and the corresponding fluorescence quenching percentage (b) of SG7-LDH on 2-NT in Example 7;
[0026] Fig.10 The fluorescence quenching graph (a) and the corresponding fluorescence quenching percentage (b) of SG7-LDH on 3-NT in Example 8;
[0027] Fig.11 The fluorescence quenching graph (a) and the corresponding fluorescence quenching percentage (b) of SG7-LDH on 4-NT in Example 9. DETAILED DESCRIPTION
[0028] Example 1
[0029] This embodiment provides a nitro sensor based on pyrene molecule excimer, and the specific steps are as follows:
[0030] The layered double hydroxide (LDH) composite material Mg2Al-SG7-LDH intercalated with organic fluorescent molecule Solvent Green 7 (8-hydroxypyrene-1,3,5-trisulfonic acid trisodium salt, abbreviated as SG7) was prepared by coprecipitation method.
[0031] SG7 molecules are simple and easy to purchase, and are typical pH-sensitive materials; LDH materials are green and environmentally friendly, cheap and easy to purchase, and can effectively reduce the industrial cost of pH sensing materials;
[0032] S1. Use freshly prepared decarbonated water to prepare 200 mL of chloride salt mixed solution: 100 mL of magnesium chloride solution (100 mmol / L) and 100 mL of aluminum chloride solution (50 mmol / L), mixed evenly in a ratio of 1:1 v / v, 200 mL of 15 mmol / L SG7 aqueous solution, and 200 mL of 0.1 mol / L sodium hydroxide solution;
[0033] S2, adding the SG7 aqueous solution into a four-necked round-bottom flask filled with nitrogen, and slowly dropping the chloride mixed solution and the sodium hydroxide solution at the same time, so that the pH of the solution in the flask is maintained at 7.5; after the chloride mixed solution and the sodium hydroxide solution are all dropped, in a nitrogen atmosphere, the mixture is stirred at a constant temperature of 20° C. and a speed of 400 rpm for 6 to 8 hours to fully age the prepared Mg2Al-SG7-LDH and uniformly increase its size, thereby obtaining a Mg2Al-SG7-LDH slurry;
[0034] S3. Wash by centrifugation for more than three times with freshly prepared carbon dioxide-free water and methanol. When the supernatant has no fluorescence under ultraviolet light, it indicates that the free SG7 monomer molecules are completely removed. Finally, store the cleaned Mg2Al-SG7-LDH in methanol at a low temperature of 0-4°C and store it at a quantitative value of 0.1g / L for later use to obtain the SG7-LDH composite material dispersion, referred to as SG7-LDH.
[0035] The product obtained by the above preparation method is as follows Figure 1 shown.
[0036] The SG7 dye is fixed in the inorganic material LDH layer, and the distance between its molecules is fixed. The short wavelength in the SG7-LDH excitation spectrum is the excitation peak of the SG7 monomer, and the long wavelength is the excitation peak of the SG7 excimer complex, such as Figure 2As shown; not only that, LDH is essentially a solid solution and can be separated by centrifugation, which can effectively recycle organic fluorescent materials and avoid environmental pollution.
[0037] The SG7 molecule itself has excellent fluorescence properties, but is easily aggregated and quenched, such as Figure 3 As shown, as the concentration of high-concentration SG7 methanol solution increases, the disordered stacking of SG7 aggregates increases, the fluorescence intensity decreases, and new fluorescence peaks are generated, corresponding to SG7 aggregates with smaller intermolecular distances and stronger π-π effects; therefore, due to the fluorescence quenching properties of SG7 itself, it is difficult to use the fluorescence quenching of SG7 aggregates to achieve nitro sensing.
[0038] The LDH layer is a topological structure, thus forcing the SG7 molecules between the layers to be arranged in an orderly manner. Although the distance between the SG7 molecules in the molecular array is close, the fluorescence quenching caused by unnecessary stacking in the free state will not occur. Therefore, sufficient SG7 excimers can be stably provided in organic solvents to realize nitro sensing in solution.
[0039] The LDH layer has good photothermal stability and can effectively increase the service life of the fluorescent material SG7 between the layers. LDH can exist in organic solvents and will not dissolve the SG7 molecules between the SG7-LDH layers. It has no adverse effect on nitro sensing. LDH is a solid solution and can be recovered by centrifugation. It is green, environmentally friendly and reusable.
[0040] Example 2
[0041] This embodiment provides a method for detecting 2-nitrophenol (2-NP) using the SG7-LDH composite material dispersion prepared in Example 1:
[0042] Dissolve 2-NP in ethanol solution to prepare a series of 2-NP solutions with concentrations of 0 to 200 ppm. Take 0.1 mL of 0.1 g / L SG7-LDH dispersion, add 1.9 mL of 2-NP solutions of different concentrations, mix well, and then test the fluorescence spectrum of the mixed solution. The excitation wavelength is 360 nm. Test the emission peak intensity of SG7-LDH at this excitation wavelength, and you can observe the fluorescence quenching of the excimer complex when it comes into contact with the nitro group.
[0043] like Figure 4 As shown, with the increase of 2-NP concentration, the fluorescence quenching ratio of SG7-LDH continued to increase. When the 2-NP concentration was 10 ppm, the fluorescence quenching ratio of SG7-LDH reached 38.56%; when the 2-NP concentration was 200 ppm, the fluorescence quenching ratio of SG7-LDH reached 99.77%.
[0044] In summary, SG7-LDH immediately underwent fluorescence quenching without time delay when in contact with 2-NP, and had good sensing performance for 2-NP;
[0045] Embodiment 3:
[0046] This embodiment provides a method for detecting 3-nitrophenol (3-NP) using the SG7-LDH composite material dispersion prepared in Example 1:
[0047] Dissolve 3-NP in ethanol solution to prepare a series of 0-200 ppm 3-NP ethanol solutions. Take 0.1 mL of 0.1 g / L SG7-LDH dispersion, add 1.9 mL of 3-NP solution of different concentrations, mix well and test the fluorescence spectrum of the mixed solution with an excitation wavelength of 360 nm.
[0048] like Figure 5 As shown, with the increase of 3-NP concentration, the fluorescence quenching ratio of SG7-LDH continued to increase. When the 3-NP concentration was 10 ppm, the fluorescence quenching ratio of SG7-LDH reached 29.29%; when the 3-NP concentration was 200 ppm, the fluorescence quenching ratio of SG7-LDH reached 90.96%.
[0049] In summary, SG7-LDH immediately underwent fluorescence quenching when in contact with 3-NP without time delay, and had good sensing performance for 3-NP.
[0050] Embodiment 4:
[0051] This embodiment provides a method for detecting nitrobenzene (NB) in the SG7-LDH composite material dispersion prepared in Example 1:
[0052] NB was dissolved in ethanol solution to prepare a series of NB solutions with concentrations of 0 to 200 ppm. 0.1 mL of 0.1 g / L SG7-LDH dispersion was added with 1.9 mL of NB solutions of different concentrations. After mixing evenly, the fluorescence spectrum of the mixed solution was tested with an excitation wavelength of 360 nm.
[0053] like Figure 6 As shown, with the increase of NB concentration, the fluorescence quenching ratio of SG7-LDH continued to increase. When the NB concentration was 10 ppm, the fluorescence quenching ratio of SG7-LDH reached 17.12%; when the NB concentration was 200 ppm, the fluorescence quenching ratio of SG7-LDH reached 53.05%.
[0054] In summary, SG7-LDH immediately underwent fluorescence quenching without time delay when it came into contact with NB, and its sensing performance to NB was slightly weaker than that of nitrophenol.
[0055] Embodiment 5:
[0056] This embodiment provides a method for detecting 1,3-dinitrobenzene (1,3-DNB) using the SG7-LDH composite material dispersion prepared in Example 1:
[0057] Dissolve 1,3-DNB in ethanol solution to prepare a series of 0-200 ppm 1,3-DNB solutions. Take 0.1 mL of 0.1 g / L SG7-LDH dispersion, add 1.9 mL of 1,3-DNB solutions of different concentrations, mix well, and then test the fluorescence spectrum of the mixed solution with an excitation wavelength of 360 nm.
[0058] like Figure 7 As shown, with the increase of 1,3-DNB concentration, the fluorescence quenching ratio of SG7-LDH continued to increase. When the 1,3-DNB concentration was 10 ppm, the fluorescence quenching ratio of SG7-LDH reached 17.12%; when the 1,3-DNB concentration was 200 ppm, the fluorescence quenching ratio of SG7-LDH reached 47.2%.
[0059] In summary, fluorescence quenching of SG7-LDH occurs immediately upon contact with 1,3-DNB without any time delay, and the sensing performance of SG7-LDH for benzene derivatives containing only nitro groups is slightly weaker than that for nitrophenol.
[0060] Embodiment 6:
[0061] This embodiment provides a method for detecting 3,5-dinitrosalicylic acid (3,5-DNS) using the SG7-LDH composite material dispersion prepared in Example 1:
[0062] Dissolve 3,5-DNS in ethanol solution to prepare a series of 0-200 ppm 3,5-DNS solutions. Take 0.1 mL of 0.1 g / L SG7-LDH dispersion, add 1.9 mL of 3,5-DNS solutions of different concentrations, mix well, and then test the fluorescence spectrum of the mixed solution with an excitation wavelength of 360 nm.
[0063] like Figure 8 As shown, with the increase of 3,5-DNS concentration, the fluorescence quenching ratio of SG7-LDH continued to increase. When the concentration of 3,5-DNS was 10 ppm, the fluorescence quenching ratio of SG7-LDH reached 38.56%; when the concentration of 3,5-DNS was 200 ppm, the fluorescence quenching ratio of SG7-LDH reached 98.43%.
[0064] In summary, SG7-LDH immediately underwent fluorescence quenching when it came into contact with 3,5-DNS without any time delay, and had good sensing performance for 3,5-DNS.
[0065] Embodiment 7:
[0066] This embodiment provides a method for detecting 2-nitrotoluene (2-NT) using the SG7-LDH composite material dispersion prepared in Example 1:
[0067] Dissolve 2-NT in ethanol solution to prepare a series of 2-NT solutions with concentrations of 0 to 200 ppm. Take 0.1 mL of 0.1 g / L SG7-LDH dispersion, add 1.9 mL of 2-NT solutions of different concentrations, mix well, and then test the fluorescence spectrum of the mixed solution with an excitation wavelength of 360 nm.
[0068] like Fig. 9 As shown, with the increase of 2-NT concentration, the fluorescence quenching ratio of SG7-LDH continued to increase. When the 2-NT concentration was 20 ppm, the fluorescence quenching ratio of SG7-LDH reached 29.29%; when the 2-NT concentration was 200 ppm, the fluorescence quenching ratio of SG7-LDH reached 62.15%.
[0069] In summary, SG7-LDH immediately underwent fluorescence quenching without time delay when it came into contact with 2-NT, and the sensing performance of p-nitrotoluene was slightly weaker than that of nitrophenol.
[0070] Embodiment 8:
[0071] This embodiment provides a method for detecting 3-nitrotoluene (3-NT) using the SG7-LDH composite material dispersion prepared in Example 1:
[0072] Dissolve 3-NT in ethanol solution to prepare a series of 3-NT solutions with concentrations of 0 to 200 ppm. Take 0.1 mL of 0.1 g / L SG7-LDH dispersion, add 1.9 mL of 3-NT solutions of different concentrations, mix well, and then test the fluorescence spectrum of the mixed solution with an excitation wavelength of 360 nm.
[0073] like Fig.10 As shown, with the increase of 3-NT concentration, the fluorescence quenching ratio of SG7-LDH continued to increase. When the 3-NT concentration was 20 ppm, the fluorescence quenching ratio of SG7-LDH reached 19.44%; when the 3-NT concentration was 200 ppm, the fluorescence quenching ratio of SG7-LDH reached 43.49%.
[0074] In summary, the fluorescence quenching of SG7-LDH occurred immediately when it came into contact with 3-NT without any time delay, and the sensing performance of SG7-LDH for nitrotoluene was slightly weaker than that for nitrophenol.
[0075] Embodiment 9:
[0076] This embodiment provides a method for detecting 4-nitrotoluene (4-NT) using the SG7-LDH composite material dispersion prepared in Example 1:
[0077] Dissolve 4-NT in ethanol solution to prepare a series of 0-200 ppm 4-NT solutions. Take 0.1 mL of 0.1 g / L SG7-LDH dispersion, add 1.9 mL of 4-NT solutions of different concentrations, mix well, and then test the fluorescence spectrum of the mixed solution with an excitation wavelength of 360 nm.
[0078] like Fig.11 As shown, with the increase of 4-NT concentration, the fluorescence quenching ratio of SG7-LDH continued to increase. When the 4-NT concentration was 20 ppm, the fluorescence quenching ratio of SG7-LDH reached 16.54%; when the 4-NT concentration was 200 ppm, the fluorescence quenching ratio of SG7-LDH reached 58.68%.
[0079] In summary, the fluorescence quenching of SG7-LDH occurred immediately when it came into contact with 4-NT without any time delay, and the sensing performance of SG7-LDH for nitrotoluene was slightly weaker than that for nitrophenol.
[0080] The above is only a preferred embodiment of the present invention and does not limit the present invention in any way. Any simple modification, change and equivalent change made to the above embodiment according to the technical essence of the invention still falls within the protection scope of the technical solution of the present invention.
Claims
1. A nitro sensor based on pyrene molecular excimer, characterized in that: The following steps are involved: S1, taking magnesium chloride solution and aluminum chloride solution and mixing them to obtain chloride salt solution; S2. Under a nitrogen atmosphere, chloride solution and sodium hydroxide solution were added dropwise to the aqueous solution of solvent green 7, and stirred at a constant temperature to obtain Mg2Al-SG7-LDH slurry; S3, Mg2Al-SG7-LDH slurry was centrifugally washed with distilled water and methanol, and then stored in a methanol solution to obtain a SG7-LDH composite material dispersion, namely, a nitro sensor.
2. A nitro sensor based on pyrene molecular excimer according to claim 1, characterized in that: The chloride solution in S1 is obtained by mixing 100 mL of a 100 mmol / L magnesium chloride solution and 100 mL of a 50 mmol / L aluminum chloride solution. 2+ The concentration is 50mmol / L, Al 3+ The concentration is 25mmol / L.
3. A nitro sensor based on pyrene molecular excimer according to claim 1, characterized in that: The concentration of the solvent green 7 aqueous solution in S2 is 15 mmol / L, the concentration of the sodium hydroxide solution is 0.1 mol / L, the volume ratio of the solvent green 7 aqueous solution, the chloride solution and the sodium hydroxide solution is 200 mL: 200 mL: 200 mL, the pH value during the constant temperature stirring process is 7.5, and the constant temperature stirring time is 6 to 8 h.
4. A nitro sensor based on pyrene molecular excimer according to claim 1, characterized in that: The concentration of the SG7-LDH composite material described in S3 is 0.1 g / L.
5. An application method of the nitro sensor based on the pyrene molecular excimer according to any one of claims 1 to 4, characterized in that: The following steps are involved: The SG7-LDH composite material dispersion is dispersed in a nitro-containing benzene derivative solution, and the mixture is evenly mixed to obtain a mixed solution, and the fluorescence spectrum of the mixed solution is tested.
6. The application method of the nitro sensor based on pyrene molecular excimer according to claim 5, characterized in that: The volume ratio of the SG7-LDH composite material dispersion to the nitro-containing benzene derivative solution is 0.1 mL:1.9 mL.
7. The application method of the nitro sensor based on pyrene molecular excimer according to claim 5, characterized in that: The excitation wavelength of the fluorescence spectrum of the test mixed solution is 360 nm.