A polyimide supported triaminophthalocyanine probe, a preparation method thereof and application thereof in detection of nitroaromatic explosives

Abstract

The application belongs to the field of explosive detection, and discloses a polyimide loaded triaminophthalocyanine probe, a preparation method thereof and application thereof in detecting nitroaromatic explosives. The probe has the following general structure formula. The probe is prepared by cross-linking copolymerization of 5,10,15-tri(4-aminophenyl)-20-phenyl porphyrin, aromatic tetracid dianhydride and aromatic organic diamine. The polyimide high-molecular cross-linked branch loaded triaminophthalocyanine compound with fluorescent light emitting performance is prepared for the first time. The probe is applied to detecting various nitroaromatic explosives by quenching fluorescence response, and the detection method is simple, and has good application prospect in the field of public security.

Description

Technical Field

[0001] This invention belongs to the field of explosives detection, and specifically relates to a polyimide-supported triaminoporphyrin probe, its preparation method, and its application in the detection of nitro aromatic explosives. Background Technology

[0002] Nitro aromatic explosives are highly toxic and persistent environmental pollutants, posing significant threats to the environment and human health, particularly in the area of ​​public safety, where they can have catastrophic consequences. In today's world, terrorism has become the leading cause of international calamity and a primary factor affecting world peace. Among all terrorist attacks, bombings are the simplest and most common method, accounting for over 70% of all terrorist attacks. With the increasing severity of counter-terrorism efforts, countries worldwide are placing greater emphasis on explosives detection, especially in densely populated areas such as airports, subways, and train stations. The development of lightweight and rapid detection equipment is urgently needed. Existing rapid detection methods for nitro aromatic explosives include trained riot dogs, gas chromatography combined with mass spectrometry, gas chromatography-capture detection, surface-enhanced Raman spectroscopy, mass spectrometry, X-ray imaging, thermal neutron analysis, electrochemical methods, and ion mobility spectrometry (IMS). However, these methods unfortunately suffer from drawbacks such as large and expensive equipment, inconvenient operation, and high detection limits. Therefore, developing highly sensitive monitoring probes is of paramount importance for preventing and responding to terrorist attacks and protecting human property and lives.

[0003] The detection technology for nitroaromatic explosives based on the principle of fluorescence quenching is considered one of the best technologies for detecting trace amounts of explosives due to its advantages such as fast detection speed, high sensitivity, good stability, small sensor size, low cost, and simple operation. Porphyrin compounds, with their conjugated planar structure, also exhibit aggregation-induced emission (AIE). Their π-electron-rich system has a natural affinity for π-electron-deficient conjugated systems like nitroaromatic explosives. This interaction can disrupt the porphyrin compound system, and the interaction between porphyrin compounds and nitro explosives provides the theoretical basis for fluorescence quenching in the determination of nitro explosives. Although there has been progress in the synthesis of porphyrin-containing polyimides and the preparation of related materials, their applications lag behind material development, especially the excellent photoelectric properties of porphyrin as a central molecule have not been effectively utilized. Improving the material structure and effectively controlling the content and distribution of porphyrin within the material are important ways to expand the applications of porphyrin-containing polymers. Summary of the Invention

[0004] In order to overcome the shortcomings and deficiencies of the existing technology, the primary objective of this invention is to provide a polyimide-supported triaminoporphyrin probe.

[0005] Another objective of this invention is to provide a method for preparing the above-mentioned polyimide-supported triaminoporphyrin probe. By designing a structurally complex triaminoporphyrin, crosslinking and copolymerizing it with aromatic tetracarboxylic dianhydride and aromatic organic diamine, a structurally stable fluorescent probe can be directly obtained. The prepared fluorescent probe can be directly used for quenching-type fluorescence response detection of various nitro aromatic explosives without additional processing.

[0006] Another object of the present invention is to provide an application of the above-mentioned polyimide-supported triaminoporphyrin probe in the detection of nitro aromatic explosives.

[0007] The objective of this invention is achieved through the following technical solution:

[0008] A polyimide-supported triaminoporphyrin probe has the following general structural formula:

[0009]

[0010] Ar is:

[0011] Ar' is:

[0012] R1, R2, R3, R4, R5, R6, and R7 are independently selected from hydrogen, fluorine, halogen, substituted or unsubstituted alkyl, substituted or unsubstituted alkoxy, and substituted or unsubstituted aryl.

[0013] m:n = 5~50:100.

[0014] The probe was prepared by co-condensation crosslinking of 5,10,15-tris(4-aminophenyl)-20-phenylporphyrin with aromatic tetracarboxylic dianhydride and aromatic organic diamine.

[0015] The preparation method of the above-mentioned polyimide-supported triaminoporphyrin probe includes the following steps:

[0016] (1) Triaminoporphyrin and an aromatic organic diamine were dissolved in dry N,N-dimethylacetamide (DMAc), and an aromatic tetracarboxylic dianhydride was added under nitrogen protection. The mixture was magnetically stirred at 0°C for 2 hours, and then heated to room temperature and stirred for 24 hours to obtain a homogeneous viscous solution of polyamic acid. The triaminoporphyrin was 5,10,15-tris(4-aminophenyl)-20-phenylporphyrin, with the following structural formula:

[0017]

[0018] (2) The homogeneous viscous solution of polyamic acid obtained in step (1) is coated on a glass plate and placed in a vacuum oven for multiple vacuuming cycles to eliminate air bubbles in the solution. Then, the high-boiling-point solvent N,N-dimethylacetamide is removed by a programmed temperature vacuum drying oven. Then, nitrogen is introduced into the oven at 300°C for thermal imidization treatment for 1 hour. Finally, the glass plate with the film is immersed in warm water to obtain a polyimide-loaded triaminoporphyrin probe.

[0019] The triaminoporphyrin described in step (1) is prepared according to the following method:

[0020] (a) Sodium nitrite was added to a trifluoroacetic acid (TFA) solution of tetraphenylporphyrin (TPP), and the mixture was stirred at room temperature for 90 seconds. The reactants were then poured into water and extracted with dichloromethane. The mixture was purified by column chromatography to obtain 5,10,15-tris(4-nitrophenyl)-20-phenylporphyrin. The molar ratio of sodium nitrite to tetraphenylporphyrin was 10:1.

[0021] (b) The 5,10,15-tris(4-nitrophenyl)-20-phenylporphyrin obtained in step (a) was reduced by adding stannous chloride and hydrochloric acid. The resulting mixture was heated to 65°C and stirred for 1 hour under argon atmosphere, then poured into cold water, neutralized to pH 8 with ammonium hydroxide, and extracted with dichloromethane until colorless. The organic layer was concentrated under vacuum and purified by alumina chromatography to obtain 5,10,15-tris(4-aminophenyl)-20-phenylporphyrin. The molar ratio of stannous chloride to 5,10,15-tris(4-nitrophenyl)-20-phenylporphyrin was 10:1.

[0022] In order to improve the flexibility and flowability of the obtained polyimide molecular chain, the aromatic organic diamine in step (1) is 4,4′-diaminodiphenyl ether (ODA) or 4,4′-(hexafluoroisopropyl)bis(o-phenylenediamine) (6FDAM). Such diamine monomers can improve the flexibility and flowability of the obtained polyimide molecular chain.

[0023] The aromatic tetracarboxylic dianhydride mentioned in step (1) is pyromellitic dianhydride (DMPA), trifluoromethyl 1,4-bis(trifluoromethyl)-2,3,5,6-benzyltetracarboxylic dianhydride (P6FDA), 4,4′-hexafluoroisopropyl-phthalic dianhydride (6FDA), 4,4′-(2,2,2-trifluoro-1-phenylethylidene)diphthalic anhydride (3FDA) or 2,2′-bis(trifluoromethoxy)-4,4′,5,5′-biphenyltetracarboxylic dianhydride (2,2′-TEFODA).

[0024] The molar ratio of triaminoporphyrin to aromatic organic diamine in step (1) is 0.05 to 0.5:1. Since the porphyrin molecule has a large volume, the apparent viscosity of the obtained polymer (porphyrin-containing polyimide) decreases as the molar content of porphyrin increases. The polymer (porphyrin-containing polyimide) obtained within this molar ratio range has a high molecular weight.

[0025] The total molar ratio of the triaminoporphyrin and aromatic organic diamine in step (1) to the aromatic tetracarboxylic dianhydride is 1:1 to 1.2. Experiments show that when the aromatic organic diamine is used as the diamine monomer and the amount of the dianhydride monomer is equal in molarity, the prepared polyimide has a higher molecular weight.

[0026] The temperature program described in step (2) is to first treat at 60℃ for 12 hours, then at 100℃ for 1 hour, then at 150℃ for 1 hour, and then at 200℃ for 1 hour.

[0027] The above-mentioned application of a polyimide-supported triaminoporphyrin probe in the detection of nitro aromatic explosives.

[0028] This invention relates to a polyimide-supported triaminoporphyrin probe, which utilizes the unique optical properties of porphyrin combined with the excellent heat resistance and chemical corrosion resistance of polyimide for the detection of explosive vapors in extreme environments. Examples include nitrobenzene vapor, 1,3-dinitrobenzene vapor, 1,3,5-trinitrobenzene vapor, 4-nitrotoluene vapor, 2,4-dinitrotoluene vapor, and 2,4,6-trinitrotoluene vapor. This is primarily due to the unique interaction between the porphyrin in the polyimide-supported triaminoporphyrin probe and these explosive vapors, causing fluorescence quenching of the porphyrin at a specific excitation wavelength, thus achieving the detection objective. Furthermore, the introduction of polyimide segments with a specific structure avoids fluorescence quenching caused by self-aggregation, and the probe exhibits good thermal and chemical stability.

[0029] The present invention has the following advantages and effects compared with the prior art:

[0030] (1) The present invention uses aromatic tetracarboxylic dianhydride and aromatic organic diamine as raw materials. Since aromatic tetracarboxylic dianhydride and aromatic organic diamine have good thermal stability and the compound has a stable three-dimensional cross-linked structure, aromatic polyimide with good thermal stability can be obtained in the end.

[0031] (2) By controlling the molar ratio of triaminoporphyrin to aromatic organic diamine in the diamine monomer and the feeding method, the content of porphyrin in polyimide-loaded triaminoporphyrin probes can be regulated.

[0032] (3) The present invention uses polyimide loaded with triaminoporphyrin probes to prepare corresponding sensors that can be sensitive to explosives such as nitrobenzene vapor, 1,3-dinitrobenzene vapor, 1,3,5-trinitrobenzene vapor, 4-nitrotoluene vapor, 2,4-dinitrotoluene vapor or 2,4,6-trinitrobenzene vapor, and picric acid vapor. The output signal is fluorescence, and the detection process can be simplified by visual inspection.

[0033] (4) The polyimide-supported triaminoporphyrin probe prepared by this invention is applied to a sensor. Compared with homogeneous sensors, it has the advantages of not contaminating the test system and being easy to recycle.

[0034] (5) The polyimide-supported triaminoporphyrin probe prepared by the present invention is applied to a sensor and has the advantages of simple probe preparation method, convenient and fast, easy sampling, low reagent consumption and high sensitivity.

[0035] (6) The preparation method of the present invention is simple, convenient to operate and highly repeatable. The polyimide-loaded triaminoporphyrin probe obtained can be widely used for trace detection of explosive vapors, and can be used for security inspection and counter-terrorism needs in various occasions. Attached Figure Description

[0036] Figure 1 Scanning electron microscope (SEM) image of a polyimide-supported triaminoporphyrin probe at 500x magnification;

[0037] Figure 2 Scanning electron microscope (SEM) image of a polyimide-supported triaminoporphyrin probe at 10,000x magnification;

[0038] Figure 3 The energy spectrum of a polyimide-supported triaminoporphyrin probe;

[0039] Figure 4 The UV spectrum of a polyimide-supported triaminoporphyrin probe;

[0040] Figure 5 The fluorescence quenching efficiency curve of PA by a polyimide-loaded triaminoporphyrin probe is shown. Detailed Implementation

[0041] The present invention will be further described in detail below with reference to the embodiments and accompanying drawings, but the embodiments of the present invention are not limited thereto.

[0042] Example 1

[0043] Sodium nitrite (0.366 g, 5.3 mmol) was added to a solution of 5,10,15,20-tetraphenylporphyrin (0.2 g, 0.326 mmol) in 10 mL of trifluoroacetic acid. After stirring for 90 seconds at room temperature, the reaction mixture was poured into 100 mL of water and extracted with dichloromethane (25 mL × 6). The layers were separated, and the organic layer was dried over anhydrous sodium sulfate. The solvent was evaporated under reduced pressure, and the mixture was purified by column chromatography to obtain 5,10,15-tris(4-nitrophenyl)-20-phenylporphyrin, the structural formula of which is as follows:

[0044]

[0045] Its mass spectrometry and proton nuclear magnetic resonance characterization data are as follows:

[0046] MS(MALDI)m / z749.8(M+):HNMR(CDCl3)6ppm:-2.80(br,2H),7.80(m,3H),8.20(m,2 H)8.40(dJ=7.50Hz.6H).8.65(dJ=7.50Hz.6H).8.80(m.6H), 8.93(d, J=5.0Hz, 2H).

[0047] The purified 5,10,15-tris(4-nitrophenyl)-20-phenylporphyrin was reduced in 0.8 g (3.55 mmol) stannous chloride and 50 mL HCl solution. The reaction mixture was heated to 65 °C under argon protection and stirred for 1 hour, then poured into 100 mL of water. The pH of the aqueous solution was adjusted to 8 with ammonium hydroxide, and the mixture was extracted with dichloromethane until colorless. The organic layer was dried with anhydrous sodium sulfate, the solvent was evaporated under reduced pressure, and the solution was purified by column chromatography to obtain 5,10,15-tris(4-aminophenyl)-20-phenylporphyrin, with the following structural formula:

[0048]

[0049] Its mass spectrometry and proton nuclear magnetic resonance characterization data are as follows:

[0050] MS (MALDI) m / z658.5 (M+): 1HNMR (CDCl3) 8ppm: -2.72 (br, 2H), 4.05 (s, 6H), 7.08 (dJ=7.82Hz , 6H), 7.76 (m, 3H), 7.99 (d, J = 7.82Hz, 6H) 8.22 (m, 2H), 8.81 (d, J = 4.69Hz, 2H), 8.92 (m, 6H).

[0051] Purified 5,10,15-tris(4-aminophenyl)-20-phenylporphyrin (0.0079 g, 0.01 mmol) and 4,4′-diaminodiphenyl ether (ODA) (0.4 g, 0.4 mmol) were dissolved in dry N,N-dimethylacetamide (DMAc) (5 mL), and pyromellitic anhydride (DMPA) (0.125 g, 0.5 mmol) was slowly added. The mixture was magnetically stirred at 0 °C for 2 hours, then heated to 25 °C and stirred for 2 hours, and finally reacted under nitrogen protection for 24 hours to obtain a homogeneous viscous solution of the corresponding polyamic acid. A homogeneous, viscous solution of polyamic acid was coated onto a glass plate and placed in a vacuum oven for repeated vacuuming to eliminate air bubbles. The high-boiling-point solvent DMAc was then removed using a programmed temperature control (60℃ for 12 hours, 100℃ for 1 hour, 150℃ for 1 hour, and 200℃ for 1 hour) vacuum drying oven. Following this, a thermal imidization treatment was performed at 300℃ with nitrogen gas for 1 hour. Finally, the glass plate with the adhered film was immersed in warm water to obtain a polyimide-loaded triaminoporphyrin probe. A 500x scanning electron microscope image of the obtained polyimide-loaded triaminoporphyrin probe is shown below. Figure 1 As shown, the scanning electron microscope image at 10000x magnification is as follows: Figure 2 As shown, the energy spectrum is as follows Figure 3 As shown, the ultraviolet spectrum is as follows Figure 4 As shown. By Figure 4 As can be seen, a distinct porphyrin absorption peak appeared in the UV absorption spectrum, indicating that porphyrin has been loaded into the polyimide molecular chain. Its structural formula is as follows:

[0052]

[0053] Take the 2cm sample prepared in Example 1 2 Polyimide-loaded triaminoporphyrin probes were immersed in picric acid (PA) aqueous solutions of different concentrations for 5 min, then removed and dried. After the membranes dried, the fluorescence intensity at the maximum wavelength before and after interaction with different concentrations of PA was recorded using a fluorescence spectrometer, and the quenching efficiency ((1-F / F0)×100%) of different PA concentration solutions on the membrane surface fluorescence intensity was calculated. The results are as follows: Figure 5 As shown in the figure. Here, F represents the fluorescence intensity of the film surface at the maximum emission wavelength (421 nm excitation wavelength) before interaction with the PA solution, F0 represents the fluorescence intensity of the film surface at the (421 nm excitation wavelength) after interaction with PA solutions of different concentrations, and M is the concentration unit ppm.

[0054] Example 2

[0055] Sodium nitrite (0.366 g, 5.3 mmol) was added to a solution of 5,10,15,20-tetraphenylporphyrin (0.2 g, 0.326 mmol) in 10 mL of trifluoroacetic acid. After stirring for 90 seconds at room temperature, the reaction mixture was poured into 100 mL of water and extracted with dichloromethane (25 mL × 6). The layers were separated, and the organic layer was dried over anhydrous sodium sulfate. The solvent was evaporated under reduced pressure by rotary evaporation, and the resulting 5,10,15-tris(4-nitrophenyl)-20-phenylporphyrin was purified by column chromatography. The structural formula of 5,10,15-tris(4-nitrophenyl)-20-phenylporphyrin is as follows:

[0056]

[0057] Its mass spectrometry and proton nuclear magnetic resonance characterization data are as follows:

[0058] MS(MALDI)m / z749.8(M+):HNMR(CDCl3)6ppm:-2.80(br,2H),7.80(m,3H),8.20(m,2 H)8.40(dJ=7.50Hz.6H).8.65(dJ=7.50Hz.6H).8.80(m.6H), 8.93(d, J=5.0Hz, 2H).

[0059] The purified 5,10,15-tris(4-nitrophenyl)-20-phenylporphyrin was reduced in 0.8 g (3.55 mmol) stannous chloride and 50 mL HCl solution. The reaction mixture was heated to 65 °C under argon protection and stirred for 1 hour, then poured into 100 mL of water. The pH of the aqueous solution was adjusted to 8 with ammonium hydroxide, and the mixture was extracted with dichloromethane until colorless. The organic layer was dried over anhydrous sodium sulfate, the solvent was evaporated under reduced pressure, and the solution was purified by column chromatography to obtain 5,10,15-tris(4-aminophenyl)-20-phenylporphyrin. Its structural formula is as follows:

[0060] Its mass spectrometry and proton nuclear magnetic resonance characterization data are as follows:

[0061] MS (MALDI) m / z658.5 (M+): 1HNMR (CDCl3) 8ppm: -2.72 (br, 2H), 4.05 (s, 6H), 7.08 (dJ=7.82Hz , 6H), 7.76 (m, 3H), 7.99 (d, J = 7.82Hz, 6H) 8.22 (m, 2H), 8.81 (d, J = 4.69Hz, 2H), 8.92 (m, 6H).

[0062] Purified 5,10,15-tris(4-aminophenyl)-20-phenylporphyrin (0.0079 g, 0.01 mmol) and 4,4′-(hexafluoroisopropyl)bis(o-phenylenediamine) (6FDAM) (1.4 g, 0.4 mmol) were dissolved in dry N,N-dimethylacetamide (DMAc) (10 mL), and pyromellitic anhydride (DMPA) (0.125 g, 0.5 mmol) was slowly added. The mixture was stirred at 0 °C for 2 hours, then heated to 25 °C and stirred for 2 hours, and then reacted under nitrogen protection for 24 hours to obtain a homogeneous viscous solution of the corresponding polyamic acid. A homogeneous viscous solution of polyamic acid was coated onto a glass plate and placed in a vacuum oven for multiple vacuum cycles to eliminate air bubbles. The high-boiling-point solvent DMAc was then removed by a programmed temperature (treatment at 60℃ for 12 hours, then at 100℃ for 1 hour, then at 150℃ for 1 hour, and then at 200℃ for 1 hour) vacuum drying oven. Nitrogen gas was then introduced into a 300℃ oven for thermal imidization treatment for 1 hour. Finally, the glass plate with the film was immersed in warm water to obtain a polyimide-loaded triaminoporphyrin probe.

[0063]

[0064] Example 3

[0065] Sodium nitrite (0.366 g, 5.3 mmol) was added to a solution of 5,10,15,20-tetraphenylporphyrin (0.2 g, 0.326 mmol) in 10 mL of trifluoroacetic acid. After stirring for 90 seconds at room temperature, the reaction mixture was poured into 100 mL of water and extracted with dichloromethane (25 mL × 6). The layers were separated, and the organic layer was dried over anhydrous sodium sulfate. The solvent was evaporated under reduced pressure by rotary evaporation. The resulting product was purified by column chromatography to obtain 5,10,15-tris(4-nitrophenyl)-20-phenylporphyrin, with the following structural formula:

[0066]

[0067] Its mass spectrometry and proton nuclear magnetic resonance characterization data are as follows:

[0068] MS(MALDI)m / z749.8(M+):HNMR(CDCl3)6ppm:-2.80(br,2H),7.80(m,3H),8.20(m,2 H)8.40(dJ=7.50Hz.6H).8.65(dJ=7.50Hz.6H).8.80(m.6H), 8.93(d, J=5.0Hz, 2H).

[0069] The purified 5,10,15-tris(4-nitrophenyl)-20-phenylporphyrin was reduced in 0.8 g (3.55 mmol) stannous chloride and 50 mL HCl solution. The reaction mixture was heated to 65 °C under argon protection and stirred for 1 hour, then poured into 100 mL of water. The pH of the aqueous solution was adjusted to 8 with ammonium hydroxide, and the mixture was extracted with dichloromethane until colorless. The organic layer was dried over anhydrous sodium sulfate, the solvent was evaporated under reduced pressure, and the solution was purified by column chromatography to obtain 5,10,15-tris(4-aminophenyl)-20-phenylporphyrin. The structural formula is as follows:

[0070]

[0071] Its mass spectrometry and proton nuclear magnetic resonance characterization data are as follows:

[0072] MS (MALDI) m / z658.5 (M+): 1HNMR (CDCl3) 8ppm: -2.72 (br, 2H), 4.05 (s, 6H), 7.08 (dJ=7.82Hz , 6H), 7.76 (m, 3H), 7.99 (d, J = 7.82Hz, 6H) 8.22 (m, 2H), 8.81 (d, J = 4.69Hz, 2H), 8.92 (m, 6H).

[0073] 5,10,15-tris(4-aminophenyl)-20-phenylporphyrin (0.659 g, 0.1 mmol) was dissolved in 10 mL of CH₂Cl₂ solution, and then 20 mL of an ethanol solution containing zinc gold acetate (0.10 g, 0.1 mmol) was added. The reaction was carried out at room temperature for 24 hours. After the reaction was completed, the unreacted zinc gold acetate was filtered off, the solvent was removed under reduced pressure, and the zinc was purified by alumina column chromatography to obtain 5,10,15-tris(4-aminophenyl)-20-phenylporphyrin zinc. The structural formula is as follows:

[0074]

[0075] Its mass spectrometry and proton nuclear magnetic resonance characterization data are as follows:

[0076] MS (MALDI) m / z721.2 (M+): 1HNMR (CDCl3) 8ppm: -2.70 (br, 2H), 4.01 (s, 6H), 7.04 (dJ=7.82Hz , 6H), 7.74 (m, 3H), 7.95 (d, J = 7.82Hz, 6H) 8.10 (m, 2H), 8.71 (d, J = 4.69Hz, 2H), 8.82 (m, 6H).

[0077] Purified zinc 5,10,15-tris(4-aminophenyl)-20-phenylporphyrin (0.0079 g, 0.01 mmol) and 4,4′-diaminodiphenyl ether (ODA) (0.4 g, 0.4 mmol) were dissolved in dry N,N-dimethylacetamide (DMAc) (5 mL), and pyromellitic anhydride (DMPA) (0.125 g, 0.5 mmol) was slowly added. The mixture was magnetically stirred at 0 °C for 2 hours, then heated to 25 °C and stirred for 2 hours. The reaction was then carried out under nitrogen protection for 24 hours to obtain a homogeneous viscous solution of the corresponding polyamic acid. A homogeneous, viscous solution of polyamic acid was coated onto a glass plate and placed in a vacuum oven for repeated vacuuming to eliminate air bubbles. The high-boiling-point solvent DMAc was then removed using a programmed temperature control (60℃ for 12 hours, 100℃ for 1 hour, 150℃ for 1 hour, and 200℃ for 1 hour) vacuum drying oven. Following this, a thermal imidization treatment was performed at 300℃ with nitrogen gas for 1 hour. Finally, the glass plate with the adhered film was immersed in warm water to obtain a polyimide-supported triaminoporphyrin probe. Its structure is as follows:

[0078]

[0079] The above embodiments are preferred embodiments of the present invention, but the embodiments of the present invention are not limited to the above embodiments. Any changes, modifications, substitutions, combinations, or simplifications made without departing from the spirit and principle of the present invention shall be considered equivalent substitutions and shall be included within the protection scope of the present invention.

Claims

1. A polyimide-supported triaminoporphyrin probe, characterized in that: The probe has the following general structural formula: Ar is: Ar' is: R1, R2, R3, R4, R5, R6, and R7 are independently selected from hydrogen, halogen, substituted or unsubstituted alkyl, substituted or unsubstituted alkoxy, and substituted or unsubstituted aryl. m:n = 5~50∶100.

2. The method for preparing a polyimide-supported triaminoporphyrin probe according to claim 1, characterized in that... The following steps are included: (1) Triaminoporphyrin and an aromatic organic diamine were dissolved in dry N,N-dimethylacetamide. An aromatic tetracarboxylic dianhydride was added under nitrogen protection. The mixture was magnetically stirred at 0°C for 2 hours, then heated to room temperature and stirred for 24 hours to obtain a homogeneous viscous solution of polyamic acid. The triaminoporphyrin was 5,10,15-tris(4-aminophenyl)-20-phenylporphyrin, with the following structural formula: (2) The homogeneous viscous solution of polyamic acid obtained in step (1) is coated on a glass plate and placed in a vacuum oven for multiple vacuuming cycles to eliminate air bubbles in the solution. Then, the high-boiling-point solvent N,N-dimethylacetamide is removed by a programmed temperature vacuum drying oven. Then, nitrogen is introduced into the oven at 300°C for thermal imidization treatment for 1 hour. Finally, the glass plate with the film is immersed in warm water to obtain a polyimide-loaded triaminoporphyrin probe.

3. The preparation method according to claim 2, characterized in that: The triaminoporphyrin described in step (1) is prepared according to the following method: (a) Sodium nitrite was added to a trifluoroacetic acid solution of tetraphenylporphyrin, and the mixture was stirred at room temperature for 90 seconds. The reactants were then poured into water and extracted with dichloromethane. The mixture was purified by column chromatography to obtain 5,10,15-tris(4-nitrophenyl)-20-phenylporphyrin. The molar ratio of sodium nitrite to tetraphenylporphyrin was 10:

1. (b) The 5,10,15-tris(4-nitrophenyl)-20-phenylporphyrin obtained in step (a) was reduced by adding stannous chloride and hydrochloric acid. The resulting mixture was heated to 65°C and stirred for 1 hour under argon atmosphere, then poured into cold water, neutralized to pH 8 with ammonium hydroxide, and extracted with dichloromethane until colorless. The organic layer was concentrated under vacuum and purified by column chromatography to obtain 5,10,15-tris(4-aminophenyl)-20-phenylporphyrin; the molar ratio of stannous chloride to 5,10,15-tris(4-nitrophenyl)-20-phenylporphyrin was 10:

1.

4. The preparation method according to claim 2, characterized in that: The aromatic organic diamine mentioned in step (1) is 4,4′-diaminodiphenyl ether or 4,4′-(hexafluoroisopropyl)bis(o-phenylenediamine).

5. The preparation method according to claim 2, characterized in that: The aromatic tetracarboxylic dianhydride mentioned in step (1) is pyromellitic dianhydride, 4,4′-hexafluoroisopropyl-phthalic dianhydride, or 4,4′-(2,2,2-trifluoro-1-phenylethylidene)diphenyl anhydride.

6. The preparation method according to claim 2, characterized in that: The molar ratio of the triaminoporphyrin to the aromatic organic diamine in step (1) is 0.05 to 0.5:1; the total molar ratio of the triaminoporphyrin and the aromatic organic diamine to the aromatic tetracarboxylic dianhydride is 1:1 to 1.

2.

7. The preparation method according to claim 2, characterized in that: The temperature program described in step (2) is to first treat at 60℃ for 12 hours, then at 100℃ for 1 hour, then at 150℃ for 1 hour, and then at 200℃ for 1 hour.

8. The application of the polyimide-supported triaminoporphyrin probe according to claim 1 in the detection of nitro aromatic explosives.

9. The application according to claim 8, characterized in that: The nitro aromatic explosive is nitrobenzene vapor, 1,3-dinitrobenzene vapor, 1,3,5-trinitrobenzene vapor, 4-nitrotoluene vapor, 2,4-dinitrotoluene vapor, or 2,4,6-trinitrotoluene vapor.

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