A fluorescent nanomaterial and its preparation method and application

Abstract

The invention discloses a fluorescent nano material and a preparation method and application thereof. The nano material has a specific and selective response to thionyl fluoride, and is aggregated into a microscopic cross-network structure with nanobelts through π-π stacking self-assembly of building units; the structural formula of the building units is as follows: the fluorescent nano material prepared by the invention has a uniform nanobelt structure, and its morphology is regular and uniform; the radial network structure in which the nanobelts are interconnected provides a high-speed transmission channel for energy transfer between molecules; and the large specific surface area is conducive to the adsorption and diffusion of thionyl fluoride gas, thereby improving the detection sensitivity of the fluorescent nano material, and has no fluorescent response to phosgene, sarin gas, tabun gas, decasulfur and oxygen difluoride, etc., has good anti-interference ability, realizes specific and high-sensitivity detection of thionyl fluoride gas, and has good application prospects.

Description

Technical Field

[0001] The invention relates to the field of organic semiconductor nanomaterials, and in particular to a fluorescent nanomaterial and a preparation method and application thereof. Background Art

[0002] Sulfonyl fluoride is a colorless, highly toxic gas that can invade the lungs, causing acute edema of the lung tissue, affecting gas exchange, causing hypoxia and congestion in the lungs and leading to death by suffocation. It has a strong, nauseating odor and can be used as a warning signal. The lethal concentration for mice and rabbits is 10×10 -6 and 50×10 -6 (V / V). Therefore, it is of great significance to detect trace amounts of it.

[0003] At present, the existing online monitors for thionyl fluoride mostly use electrochemical methods. The main problems are that the electrode selectivity is not high and side reactions are prone to occur; the electrode is prone to form adsorption layers and oxide films, and fouling the electrode causes the voltage to increase. Other traditional detection methods that can be used to detect thionyl fluoride gas include: ion mobility spectrometry, mass spectrometry, bioenzyme chemical sensors, surface acoustic waves and fluorescence detection. However, these methods have the disadvantages of high cost, complex detection methods, insufficient sensitivity and specificity, expensive and non-portable instruments, etc., and cannot meet the on-site use characteristics of high sensitivity, high specificity, low cost and portability.

[0004] In recent years, organic semiconductor nanomaterials have been increasingly used in the fields of field effect transistors, electroluminescent diodes, solar cells, photodetection, photocatalysis, and biosensors due to their unique and adjustable chemical structures and optoelectronic properties. However, organic materials themselves have weak chemical bonds and low carrier mobility, resulting in poor stability. Therefore, nanoassembly of organic semiconductors and construction of heterostructures to obtain zero-dimensional, one-dimensional, two-dimensional or multi-component composite nanoorganic materials have become a research hotspot in recent years. Among them, fluorescent nanomaterials prepared by π-conjugated organic molecules as building blocks can be used as effective fluorescent quantum materials to achieve high sensitivity and high selectivity for toxic and harmful substances. At the same time, there are a variety of nano-organic fluorescent effect materials with different luminescence properties. This is because the photophysical properties of organic semiconductor materials are mainly determined by the chemical structure and aggregation state of electron delocalization or π-conjugated components. Therefore, their photophysical properties can be regulated by reasonable molecular structure design, and any change in the parameters of their photophysical properties can be used for sensing detection, which has the advantages of rapidity, sensitivity, accuracy, and high selectivity, thereby realizing the detection of the corresponding substances. Summary of the invention

[0005] In view of the above-mentioned deficiencies in the prior art, the technical problems to be solved by the present invention are: to provide a fluorescent nanomaterial and a preparation method thereof, thereby enriching the types and selectivity of existing nanomaterials; the present invention also provides the application of the fluorescent nanomaterial in the detection of thionyl fluoride, thereby solving the problems of low sensitivity and specificity, complicated operation steps, high cost, etc. in the existing detection methods.

[0006] In order to solve the above technical problems, the present invention adopts the following technical solution: a fluorescent nanomaterial, the nanomaterial has a specific and selective response to thionyl fluoride, and the building units are self-assembled by π-π stacking to form a microscopic cross-network structure with nanobelts; the structural formula of the building unit is as follows:

[0007]

[0008] Another object of the present invention is to provide a method for preparing the above-mentioned building block, and the synthetic route is as follows:

[0009]

[0010] The specific steps include:

[0011] 1) Preparation of intermediate compound B:

[0012] Compound A is placed in imidazole and heated to 130°C, then tridecane-7-amine is added, reacted for 1-2 hours, anhydrous ethanol and hydrochloric acid solution are added in sequence, stirred overnight, the product is filtered to collect the solid, water is added to the obtained solid to rinse until neutral, and the intermediate compound B is obtained after reduced pressure rotary evaporation;

[0013] 2) Preparation of intermediate compound D:

[0014] The intermediate compound B obtained in step 1) and 4-aminophenol are placed in imidazole and heated to 130° C. for reaction for 1 to 2 hours, and then anhydrous ethanol and hydrochloric acid solution are added in sequence, stirred overnight, and then the product is filtered to collect the solid, and the obtained solid is separated by column chromatography to obtain the intermediate compound D;

[0015] 3) Preparation of building blocks:

[0016] The intermediate compound D and compound E obtained in step 2) are placed in a chloroform solution, and diisopropyl azodicarboxylate and triphenylphosphine are added to react for 1 to 2 hours, stirred overnight, and then separated and extracted. The obtained solid is separated by column chromatography to obtain the building molecule.

[0017] Preferably, the mass fraction of the hydrochloric acid solution is 36%; the eluent in the column chromatography is dichloromethane / methanol, and the volume ratio of dichloromethane to methanol is 50:1 to 100:1.

[0018] Preferably, the molar ratio of compound A to tridecane-7-amine is 1:1 to 1:1.2.

[0019] Preferably, the molar ratio of the intermediate compound B to 4-aminophenol is 1:1 to 1:1.2.

[0020] Preferably, the molar ratio of the intermediate compound D to the compound E is 1:1 to 1:1.2.

[0021] Another object of the present invention is to provide a method for preparing the above-mentioned fluorescent nanomaterial, comprising the following steps: firstly synthesizing the building unit, then dissolving it in a benign solvent, then adding a poor solvent, and after standing for 1 to 3 days, sucking out the floccules precipitated from the reaction product, and obtaining the fluorescent nanomaterial after the organic solvent evaporates naturally.

[0022] Preferably, the good solvent is chloroform, and the poor solvent is ethanol, ether, n-hexane or n-pentane; the volume ratio of the good solvent to the poor solvent is 1:5 to 1:20.

[0023] Another object of the present invention is to provide the use of the porous membrane made by the preparation method of the fluorescent nanomaterial for detecting thionyl fluoride gas.

[0024] Preferably, the method for detecting thionyl fluoride gas comprises the following steps:

[0025] S1: uniformly coating the porous membrane on the inner wall of a glass tube, exciting the porous membrane with an excitation light source having a wavelength of 450 nm, and then detecting the fluorescence intensity of the porous membrane at 600-630 nm;

[0026] S2: contacting the porous membrane in the excited state in step S1 with the gas to be detected, and then detecting the fluorescence intensity of the porous membrane at 600-630nm. When the obtained fluorescence intensity is significantly enhanced, the gas to be detected contains thionyl fluoride gas; the detection concentration of the thionyl fluoride gas is at the ppm level.

[0027] Compared with the prior art, the present invention has the following beneficial effects:

[0028] 1. The fluorescent nanomaterials involved in the present invention are prepared by self-assembly of p-mercaptophenyl ether as the end of perylene imide. In the excited state of the nanomaterial, due to the presence of p-mercaptophenyl ether, the flexibility of the end molecules increases, so that intramolecular twisting occurs, the energy within the molecule is dispersed, and the molecular fluorescence is suppressed. When sulfenyl fluoride contacts the nanomaterial, sulfenyl fluoride can quickly oxidize the sulfhydryl group of p-mercaptophenyl ether, thereby increasing the intramolecular steric hindrance, reducing the intramolecular twisting, and enhancing the molecular fluorescence intensity of the nanomaterial. Therefore, the nanomaterials of the present invention can be used for rapid and highly selective detection of sulfenyl fluoride gas, and have good market application prospects.

[0029] 2. The present invention provides a method for preparing a fluorescent nanomaterial. The synthetic method is simple and easy to control, and the raw materials are cheap and easily available. The prepared nanomaterial has a uniform nanobelt structure of micrometer size, and its morphology is regular and uniform. The radial network structure of the nanobelts interconnected provides a high-speed transmission channel for energy transfer between molecules. At the same time, its large specific surface area is conducive to the adsorption and diffusion of thionyl fluoride gas, thereby improving the detection sensitivity of the fluorescent nanomaterial; the high fluorescence quantum yield is conducive to further improving the detection sensitivity, greatly reducing the minimum detection limit of thionyl fluoride gas.

[0030] 3. The present invention provides a method for using fluorescent nanomaterials to detect thionyl fluoride gas. The method is simple to operate, can detect thionyl fluoride gas quickly and in real time, and has no fluorescent response to phosgene, sarin gas, tabun gas, disulfide decafluoride and oxygen difluoride, etc. It has good anti-interference ability, realizes specific and highly sensitive detection of thionyl fluoride gas, and has good application prospects. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] Figure 1 It is the MALDI-TOF mass spectrum of the building blocks of the fluorescent nanomaterial of the present invention.

[0032] Figure 2 It is a scanning electron microscope image of the fluorescent nanomaterial of the present invention.

[0033] Figure 3 This is a fluorescence intensity diagram of the reaction between the fluorescent nano material of the present invention and thionyl fluoride poison gas.

[0034] Figure 4 It is a fluorescence enhancement linear graph of the concentration reaction between the fluorescent nano material of the present invention and thionyl fluoride poison gas.

[0035] Figure 5 The fluorescent nanomaterial of the present invention has a specific selectivity for thionyl fluoride gas; A is phosgene, C is sarin gas, C is tabun gas, D is disulfur decafluoride, and E is oxygen difluoride. DETAILED DESCRIPTION

[0036] The present invention will be further described in detail with reference to the examples. The experimental methods used in the following examples are conventional methods unless otherwise specified. The materials, reagents, etc. used in the following examples are all commercially available unless otherwise specified.

[0037] 1. A method for preparing fluorescent nanomaterials

[0038] Example

[0039] The process for preparing a fluorescent nanomaterial having a fluorescent response to thionyl fluoride is as follows:

[0040]

[0041] The specific steps include:

[0042] 1) Preparation of intermediate compound B:

[0043] 392 mg of compound A was placed in 10 g of imidazole, heated to 130 ° C, and then 199 mg of tridecane-7-amine was added, and the reaction was continued for 1-2 hours. Then 100 ml of anhydrous ethanol and 100 ml of a 36% hydrochloric acid solution were added in sequence, and the mixture was stirred overnight. The product was filtered to collect the solid, and water was added to the obtained solid to rinse it until it was neutral. After vacuum rotary evaporation, the intermediate compound B was obtained;

[0044] 2) Preparation of intermediate compound D:

[0045] 550 mg of intermediate compound B and 109 mg of 4-aminophenol were placed in 5 g of imidazole, heated to 130° C., reacted for 1-2 hours, and then 50 ml of anhydrous ethanol and 50 ml of a 36% hydrochloric acid solution were added in sequence, stirred overnight, the product was filtered to collect the solid, and the crude product was purified by column chromatography with a dichloromethane / methanol (v / v) = 100:1 eluent to obtain 130 mg of intermediate compound D.

[0046] 1 HNMR(δ=8.63(d,4H,J=8.0Hz),8.59(d,4H,J=8.0Hz),7.12(d,2H,J=8.73Hz),6.69(d,2 H,J=8.8Hz),5.11(m,1H),2.18(m,2H),1.84(m,2H),1.18-1.20(m,16H),0.79(t,6H)).

[0047] 3) Preparation of fluorescent nanomaterial building blocks:

[0048] 66 mg of intermediate compound D and 15 mg of compound E were placed in 10 mL of chloroform, and then 26 mg of triphenylphosphine and 25 mg of diisopropyl azodicarboxylate (DIAD) were added and stirred at room temperature overnight. The mixture was separated and extracted, and the crude product was purified by column chromatography with dichloromethane / methanol (v / v) = 100:1 as eluent to obtain 19 mg of the target product building unit.

[0049] 1 HNMR(δ=8.63(d,4H,J=8.0Hz),8.59(d,4H,J=8.0Hz),7.42(d,2H,J=7.7Hz),7.35(d,2H,J=6.6Hz),6.98 (d,2H,J=6.8Hz),5.11(m,1H),4.56(s,2H),2.18(m,2H),1.84(m,2H),1.18-1.20(m,16H),0.79(t,6H)).

[0050] 4) Preparation of fluorescent nanomaterials:

[0051] The building block obtained in step 3) is dissolved in chloroform, and then ethanol is added to make the volume ratio of chloroform to ethanol be 1:10. After standing for 1 to 3 days, the flocculent precipitated in the reaction product is sucked out, and the fluorescent nanomaterial is obtained after the organic solvent evaporates naturally.

[0052] The building blocks obtained in this example were subjected to MALDI-TOF mass spectrometry detection. The results are as follows: Figure 1 shown.

[0053] As can be seen from the figure, the molecular weight of the constructed molecule obtained by the present invention is measured to be 772.4, corresponding to the molecular weight of the target product 772.3, and there is no other impurity molecular weight.

[0054] In summary, the structural formula of the building block obtained in the present invention is as follows:

[0055]

[0056] The morphology of the fluorescent nanomaterial obtained in this example was observed under a scanning electron microscope. Figure 2 shown.

[0057] As can be seen from the figure, the nanomaterials formed by the present invention are all uniform nanobelt structures with a width of 20 microns, and their morphology is regular and uniform. The nanobelts are interconnected to form a one-dimensional organic semiconductor material with a radial network structure, and their large specific surface area is conducive to the adsorption and diffusion of thionyl fluoride gas.

[0058] 2. Application of fluorescent nanomaterials in the detection of thionyl fluoride gas.

[0059] The fluorescent nano material obtained by the invention is dispersed in a poor solvent and then evaporated naturally to form a porous membrane structure, and then the porous membrane is evenly coated on the inner wall of a glass tube to form a reactor for detecting thionyl fluoride poison gas.

[0060] 1. Excite the porous membrane in the reactor with an excitation light source having a wavelength of 450 nm, and then detect the fluorescence intensity of the porous membrane at 600-630 nm; then contact the porous membrane in the excited state with 25 ppm level thionyl fluoride gas, and detect the fluorescence intensity of the porous membrane at 600-630 nm at different times. The results are as follows: Figure 3 shown.

[0061] It can be seen from the figure that compared with before contact with thionyl fluoride gas, the fluorescence intensity of the porous membrane is significantly enhanced after contact with thionyl fluoride gas, the response speed is fast, the sensitivity is high, and the fluorescence signal is stable.

[0062] 2. Excite the porous membrane in the reactor with an excitation light source having a wavelength of 450 nm, and then detect the fluorescence intensity of the porous membrane at 600-630 nm; then contact the porous membrane in the excited state with 5 ppm, 10 ppm, 15 ppm, 20 ppm, 25 ppm, 30 ppm, 35 ppm, 40 ppm, and 45 ppm of thionyl fluoride gas respectively, and detect and record the difference between the fluorescence intensity of the porous membrane at 600-630 nm and the fluorescence intensity before contact. The results are as follows: Figure 4 shown.

[0063] As can be seen from the figure, as the concentration of thionyl fluoride gas increases, the fluorescence intensity difference increases accordingly, and different concentrations of thionyl fluoride gas have a good linear relationship with the fluorescence enhancement intensity. It can be seen that the present invention has a wide linear range and high detection sensitivity, and can detect low concentrations of thionyl fluoride gas.

[0064] 3. Excite the porous membrane in the reactor with an excitation light source having a wavelength of 450 nm, and then detect the fluorescence intensity of the porous membrane at 600-630 nm; then contact the porous membrane in the excited state with the gas to be tested, and detect the fluorescence intensity of the porous membrane at 600-630 nm at different times, wherein the gas to be tested is phosgene with a concentration of 100 ppm, sarin gas with a concentration of 100 ppm, tabun gas with a concentration of 100 ppm, disulfur decafluoride with a concentration of 100 ppm, and oxygen difluoride with a concentration of 100 ppm, respectively. The results are as follows: Figure 5 shown.

[0065] As can be seen from the figure, the fluorescence intensity of the porous membrane of the present invention is basically not affected after contact with phosgene, sarin gas, tabun gas, disulfur decafluoride or oxygen difluoride, which can be ignored, that is, there is no fluorescence response. It can be seen that the fluorescent nanomaterial of the present invention has good selectivity for thionyl fluoride gas and is not interfered by other gases.

[0066] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

Claims

1. A fluorescent nanomaterial, characterized in that: The nanomaterial has a specific and selective response to thionyl fluoride, and the building units are self-assembled by π-π stacking to form a microscopic cross-network structure with nanobelts; the structural formula of the building unit is as follows:

2. A method for preparing a building unit as claimed in claim 1, characterized in that: Its synthetic route is as follows: The specific steps include: 1) Preparation of intermediate compound B: Compound A is placed in imidazole and heated to 130°C, then tridecane-7-amine is added, reacted for 1-2 hours, anhydrous ethanol and hydrochloric acid solution are added in sequence, stirred overnight, the product is filtered to collect the solid, water is added to the obtained solid to rinse until neutral, and the intermediate compound B is obtained after reduced pressure rotary evaporation; 2) Preparation of intermediate compound D: The intermediate compound B obtained in step 1) and 4-aminophenol are placed in imidazole and heated to 130° C. for reaction for 1 to 2 hours, and then anhydrous ethanol and hydrochloric acid solution are added in sequence, stirred overnight, and then the product is filtered to collect the solid, and the obtained solid is separated by column chromatography to obtain the intermediate compound D; 3) Preparation of building blocks: The intermediate compound D and compound E obtained in step 2) are placed in a chloroform solution, and diisopropyl azodicarboxylate and triphenylphosphine are added in sequence to react for 1 to 2 hours, stirred overnight, and then separated and extracted. The obtained solid is separated by column chromatography to obtain the building block.

3. The method for preparing the building unit according to claim 2, characterized in that: The mass fraction of the hydrochloric acid solution is 36%; the eluent in the column chromatography is dichloromethane / methanol, and the volume ratio of dichloromethane to methanol is 50:1-100:

1.

4. The method for preparing the building unit according to claim 3, characterized in that: The molar ratio of the compound A to tridecane-7-amine is 1:1 to 1:1.

2.

5. The method for preparing the building unit according to claim 3, characterized in that: The molar ratio of the intermediate compound B to 4-aminophenol is 1:1 to 1:1.

2.

6. The method for preparing the building unit according to claim 3, characterized in that: The molar ratio of the intermediate compound D to the compound E is 1:1 to 1:1.

2.

7. A method for preparing the fluorescent nanomaterial as claimed in claim 1, characterized in that: The method comprises the following steps: firstly synthesizing the building unit, then dissolving it in a good solvent, then adding a poor solvent, standing for 1 to 3 days, sucking out the floccules precipitated from the reaction product, and obtaining the fluorescent nanomaterial after the organic solvent evaporates naturally; The good solvent is chloroform, and the poor solvent is ethanol, ether, n-hexane or n-pentane; the volume ratio of the good solvent to the poor solvent is 1:5 to 1:

20.

8. Use of a porous membrane made of the fluorescent nanomaterial according to claim 1 for detecting thionyl fluoride gas.

9. The use according to claim 8, characterized in that: The method for detecting thionyl fluoride poison gas comprises the following steps: S1: uniformly coating the porous membrane on the inner wall of a glass tube, exciting the porous membrane with an excitation light source having a wavelength of 450 nm, and then detecting the fluorescence intensity of the porous membrane at 600-630 nm; S2: contacting the porous membrane in the excited state in step S1 with the gas to be detected, and then detecting the fluorescence intensity of the porous membrane at 600-630nm. When the obtained fluorescence intensity is significantly enhanced, the gas to be detected contains thionyl fluoride gas; the detection concentration of the thionyl fluoride gas is at the ppm level.

Images