Phenanthro[9,10]pyrazine conjugated microporous polymer, photoelectric sensor based on the polymer, preparation method and application thereof

Abstract

The present invention belongs to the technical field of photoelectric sensors, and provides a phenanthro[9,10]pyrazine conjugated microporous polymer, a photoelectric sensor based on the polymer, a preparation method and an application thereof. The conjugated microporous polymer of the present invention is recorded as CMP-1, and its structure is shown in formula (I). The preparation method is to react 2,7-dibromophenanthroquinone and 1,2,4,5-benzenetetramine tetrahydrochloride to obtain an intermediate monomer compound 3, and then the intermediate compound 3 is coupled with 1,4-diethynylbenzene under the action of a palladium catalyst to obtain the intermediate compound 3. The structure of the intermediate compound 3 is shown in formula (II). The conjugated microporous polymer CMP-1 is modified on an ITO electrode to obtain a CMP / IT O sensor, which can be used for the detection of rifampicin. The sensor obtained by the present invention has high sensitivity and good selectivity for the detection of rifampicin, and good stability and reproducibility, thereby achieving the purpose of rapid quantitative detection of rifampicin.

Description

Technical Field

[0001] The present invention relates to the technical field of photoelectric sensors, and in particular to a phenanthro[9,10]pyrazine conjugated microporous polymer, a photoelectric sensor based on the polymer, and a preparation method and application thereof. Background Art

[0002] Rifampicin (RIF), also known as rifamycin and weifuxian, is an important semisynthetic broad-spectrum antibiotic in the rifamycin family and is widely used in clinical treatment. Clinical trials have demonstrated that RIF is a first-line anti-tuberculosis drug with excellent antibacterial activity against a wide range of pathogens, with significant success in treating both Gram-positive and Gram-negative bacteria. However, RIF can induce hepatotoxicity, gastrointestinal reactions, respiratory abnormalities, and other adverse reactions. Therefore, the development of a sensor to measure RIF in real-world samples is crucial. With technological advances, a growing number of analytical techniques are being used for the quantitative analysis of RIF, including high-performance liquid chromatography, liquid chromatography-mass spectrometry, spectrophotometry, and chemiluminescence analysis. Compared to these analytical methods, photoelectrochemical methods offer advantages such as ease of automation, high sensitivity, low detection limits, and low cost. They are also more easily integrated with other analytical techniques, leading to widespread interest in electrochemical analysis for drug determination.

[0003] Conjugated microporous polymers (CMPs) are a class of organic porous materials constructed from fully conjugated molecular chains. They possess a conjugated three-dimensional backbone and inherent micropores with pore sizes below 2 nm. CMPs maintain the rigidity of their molecular network by constructing a conjugated system and are typically composed of lightweight structures such as C, H, N, and B. CMPs contain macromolecules within a microporous network, containing building blocks that produce π-π conjugation. The conjugated molecular chains impart reversible electrochemical doping properties to the polymers, while their microporous structure provides stable charge carrier transport. The abundance of π-π structures within CMPs creates permanent micropores. CMPs possess excellent properties such as large surface area, high stability, and precisely tunable pore size and volume. Their unique internal structure holds immense potential for applications in various areas of life and production. To date, CMPs have demonstrated promising applications in gas storage, catalysis, adsorption, iodine adsorption, molecular separation, and clean energy. Due to the existence of a relatively special π-π conjugated system, CMPs have now shown great market value in organic optoelectronic materials, light-controlled switches, chemical and biological sensors, and new optical materials.

[0004] The present invention uses a homemade phenanthro[9,10]pyrazine conjugated microporous polymer CMP-1 modified electrode to obtain a photoelectrochemical sensor, which can perform quantitative analysis of rifampicin. There is currently no related report. Summary of the Invention

[0005] The object of the present invention is to address the above-mentioned problems and provide a phenanthro[9,10]pyrazine conjugated microporous polymer, a photoelectric sensor based on the polymer, a preparation method and an application thereof. The present invention modifies an electrode with a conjugated microporous polymer CMP-1 to obtain a photoelectrochemical sensor, which can perform quantitative analysis of rifampicin. The obtained sensor has high sensitivity and good selectivity, as well as good stability and reproducibility, thereby achieving the purpose of rapid quantitative detection of rifampicin.

[0006] In order to achieve the above object, the technical solution adopted by the present invention is as follows:

[0007] A phenanthro[9,10]pyrazine conjugated microporous polymer is provided. The conjugated microporous polymer is designated as CMP-1, and its structure is shown in formula (I):

[0008]

[0009] A method for preparing a conjugated microporous polymer is provided. 2,7-dibromophenanthrenequinone and 1,2,4,5-benzenetetramine tetrahydrochloride are reacted to prepare an intermediate monomer compound 3. The intermediate compound 3 is then reacted with 1,4-diethynylbenzene in the presence of a palladium catalyst to undergo a Sonog asihra-Hagihara coupling reaction to prepare the conjugated microporous polymer. The structure of the intermediate compound 3 is shown in formula (II):

[0010]

[0011] The preparation method of CMP-1 provided by the present invention specifically comprises the following steps:

[0012] (1) Synthesis of intermediate monomer compound 3: 2,7-dibromophenanthrenequinone and 1,2,4,5-benzenetetramine tetrahydrochloride were accurately weighed in a molar ratio of 2 to 2.5:1 and placed in a reaction vessel A. Glacial acetic acid was added and nitrogen was purged several times. Under nitrogen protection, the mixture was heated to 115 to 125°C and refluxed under condensation for 10 to 15 hours. After the reaction was completed, the mixture was cooled to room temperature and the suspension was filtered under reduced pressure to obtain a brown-red solid. The solid was then rinsed with hot water and hot ethanol and finally dried to obtain the intermediate monomer compound 3.

[0013] (2) Synthesis of CMP-1: 1,4-diethynylbenzene and intermediate monomer compound 3 were accurately weighed in a molar ratio of 1 to 1.5:1 and added to reaction vessel B. Catalysts tetrakis(triphenylphosphine)palladium and copper iodide were added to reaction vessel B and nitrogen was replaced several times. N,N-dimethylformamide and triethylamine were added in a volume ratio of 1:1 to reaction vessel C, nitrogen was replaced several times, nitrogen was introduced to remove oxygen, and the mixture was transferred to reaction vessel B containing the reactants. The mixture was heated to 88 to 95°C and stirred under reflux under nitrogen protection. After the reaction was completed, the mixture was cooled to room temperature. The suspended matter was filtered under reduced pressure, rinsed and filtered to remove unreacted monomers or catalyst residues. The polymer was further purified by Soxhlet extraction with dichloromethane. Finally, the polymer CMP-1 was obtained by vacuum drying.

[0014] In the present invention, preferably, in step (1), the temperature of the hot water and hot ethanol is 65-75°C.

[0015] In the present invention, preferably, in step (2), the amount of the catalysts tetrakis(triphenylphosphine)palladium and copper iodide used is 8-15% by weight of the intermediate monomer compound 3.

[0016] In the present invention, preferably, the Soxhlet extraction time is 60 to 90 hours.

[0017] The present invention also provides an application of the conjugated microporous polymer CMP-1, which comprises modifying the conjugated microporous polymer CMP-1 on an ITO electrode to obtain a CMP / ITO electrode for detecting rifampicin.

[0018] In the present invention, preferably, the modification method is to take the conjugated microporous polymer CMP-1 composite material into a 2wt% chitosan acetic acid solution, ultrasonically disperse the CMP in the chitosan solution to prepare a suspension, then use a pipette to transfer the CMP suspension and evenly drop it onto the conductive surface of the cleaned conductive glass, and then dry the modified CMP / ITO electrode naturally or use an infrared lamp to dry it.

[0019] In the present invention, preferably, the method used for detecting rifampicin is:

[0020] (1) Prepare a rifampicin standard solution with a gradient concentration, use a CMP / ITO electrode as the working electrode, an Ag-AgCl electrode as the reference electrode, and a platinum wire electrode as the auxiliary electrode to form a three-electrode system, use blue light as the light source, use PBS solution as the buffer solution, add the rifampicin standard solution to the buffer solution, set the bias voltage to 0 V, and use the time-current method to test, and obtain a linear relationship between the photocurrent and the logarithm of the standard modification solution concentration;

[0021] (2) Under the same conditions as step (1), the sample solution to be tested is added to the buffer solution, the photocurrent response of the sample solution to be tested is detected, and the concentration of rifampicin in the sample solution to be tested is obtained according to the measured photocurrent intensity using the linear relationship obtained in step (1).

[0022] In the present invention, preferably, the concentration of the PBS solution is 0.01 mol·L -1 , pH value is 5.5~6.5.

[0023] In summary, due to the adoption of the above technical solution, the beneficial effects of the present invention are:

[0024] 1. The present invention uses 2,7-dibromophenanthrenequinone and 1,2,4,5-benzenetetramine tetrahydrochloride to react to prepare an intermediate monomer compound 3, and then the intermediate compound 3 and 1,4-diethynylbenzene undergo a Sonogasihra-Hagihara coupling reaction in the presence of a palladium catalyst to prepare a conjugated microporous polymer CMP-1. The method has the advantages of simple operation, low cost, good synthesis effect and high yield.

[0025] 2. The conjugated microporous polymer CMP-1 prepared in this invention has excellent characteristics such as large specific surface area, high stability, and high porosity. The CMP-1 material was modified onto the surface of an ITO glass electrode to construct a photoelectrochemical sensor for the detection of rifampicin. Studies have shown that in a phosphate buffer solution with a pH of 6.5, the CMP-modified electrode exhibits a strong photoresponse to rifampicin (RIF). -9 ~1.00×10 -5 mol / L -1 Within the concentration range, the current and concentration of rifampicin showed a good linear relationship, and the linear equation was I = -0.0198x + 1.0 × 10 -6 (R 2 =0.9984), detection limit 2.68×10 -9 mol / L. The sensor can still accurately measure RIF in an environment with 100 times the concentration of ascorbic acid, demonstrating excellent stability and reproducibility. In actual sample testing, the recovery rate of rifampicin capsules ranged from 99.5% to 101.4%, and the recovery rate of rifampicin eye drops ranged from 96.7% to 101.7%. The method of this invention provides a rapid and accurate method for the detection of rifampicin. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] Figure 1 This is the infrared spectrum of CMP-1 prepared in Example 1;

[0027] Figure 2 This is a scanning electron microscope image of CMP-1 prepared in Example 1;

[0028] Figure 3 This is the X-ray diffraction pattern of CMP-1 prepared in Example 1;

[0029] Figure 4 This is the thermogravimetric analysis diagram of CMP-1 prepared in Example 1;

[0030] Figure 5 This is the XPS spectrum of CMP-1 prepared in Example 1;

[0031] Figure 6 This is the nuclear magnetic resonance spectrum of CMP-1 prepared in Example 1;

[0032] Figure 7 This is the pore size distribution diagram of CMP-1 prepared in Example 1;

[0033] Figure 8 The nitrogen adsorption / desorption isotherm of CMP-1 prepared in Example 1;

[0034] Figure 9 Cyclic voltammetry characterization diagrams of different modified electrodes;

[0035] Figure 10 Electrochemical impedance spectroscopy (EIS) characterization diagrams of different modified electrodes;

[0036] Figure 11 The photocurrent response diagram of each electrode is measured by time-current method;

[0037] Figure 12 This is the photocurrent response diagram of the CMP / ITO sensor to different concentrations of rifampicin;

[0038] Figure 13 This is the standard curve of the photocurrent response to different concentrations of rifampicin;

[0039] Figure 14 The reproducibility of CMP / ITO modified electrodes;

[0040] Figure 15 The stability of CMP / ITO modified electrodes;

[0041] Figure 16 The selectivity of CMP / ITO modified electrode at different concentrations. DETAILED DESCRIPTION

[0042] The following will clearly and completely describe the technical solutions of the present invention in conjunction with the embodiments of the present invention. Obviously, the embodiments described are only some embodiments of the present invention, not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0043] The phenanthro[9,10]pyrazine conjugated microporous polymer provided by the present invention is denoted as CMP-1, and its structure is shown in formula (I):

[0044]

[0045] In an embodiment of the present invention, the preparation method of CMP-1 is as follows: 2,7-dibromophenanthrenequinone and 1,2,4,5-benzenetetramine tetrahydrochloride are reacted to prepare an intermediate monomer compound 3, and then the intermediate compound 3 is reacted with 1,4-diethynylbenzene in the presence of a palladium catalyst to undergo a Sonogasihra-Hagihara coupling reaction to prepare the compound. The preparation route is as follows:

[0046]

[0047] 1. Implementation

[0048] Example 1

[0049] The preparation method of phenanthro[9,10]pyrazine conjugated microporous polymer specifically comprises the following steps:

[0050] (1) Synthesis of intermediate monomer compound 3: 1.4172 g of 2,7-dibromophenanthrenequinone and 0.5150 g of 1,2,4,5-benzenetetramine tetrahydrochloride were accurately weighed in a molar ratio of 2.15:1 and placed in a 50 mL round-bottom flask. 50 mL of glacial acetic acid was added and nitrogen was replaced three times. Under nitrogen protection, the mixture was heated to 120°C and refluxed for 12 h. After the reaction was completed, the mixture was cooled to room temperature and the suspension was filtered under reduced pressure to obtain a brown-red solid. The solid was then rinsed three times with 70°C hot water and three times with 70°C hot ethanol. Finally, the solid was dried in a vacuum drying oven at 50°C for 12 h to obtain 1.2006 g of intermediate monomer compound 3 with a yield of 83%.

[0051] (2) Synthesis of CMP-1: 0.0488 g of 1,4-diethynylbenzene and 0.1030 g of intermediate monomer compound 3 were accurately weighed in a molar ratio of 1 to 1.5:1 and added to a 100 mL two-necked flask. 10 mg of catalyst tetrakis(triphenylphosphine)palladium and 10 mg of copper iodide were added to the two-necked flask and nitrogen was replaced several times. 5 mL of N,N-dimethylformamide and 5mL triethylamine were replaced with nitrogen several times, and nitrogen was introduced to deoxygenate for 20 minutes, and then transferred into a 100mL two-necked flask containing the reactants; heated to 90°C, stirred and refluxed under nitrogen protection for 72 hours, and after the reaction was completed, cooled to room temperature; the suspended matter was filtered under reduced pressure and rinsed and filtered with chloroform, double distilled water, methanol and acetone respectively to remove unreacted monomers or catalyst residues; then Soxhlet extraction was performed with dichloromethane for 72 hours to further purify the polymer; finally, vacuum dried at 70oC for 24 hours to obtain 0.1015g of polymer CMP-1.

[0052] Preparation of photoelectric sensors

[0053] Accurately weigh 10 mg of the CMP composite material into 1 mL of a 2% chitosan acetic acid solution. Ultrasonicate for 30 minutes to fully disperse the CMP in the chitosan solution to prepare a suspension. Then, use a pipette to evenly apply 10 μL of the CMP suspension onto the conductive surface of a clean conductive glass. Allow the modified CMP / ITO electrode to air dry or dry under an infrared lamp before use. The ITO electrode used in this example measures 3 cm x 1 cm. After sealing with insulating adhesive, the modified area is 1 cm x 1 cm.

[0054] The prepared CMP / ITO electrode was used for the detection of rifampicin. The specific method was as follows:

[0055] (1) Prepare gradient concentrations of rifampicin standard solutions. A three-electrode system was formed using a CMP / ITO electrode as the working electrode, an Ag-AgCl electrode as the reference electrode, and a platinum wire electrode as the auxiliary electrode. A 10 W blue light source was used as the light source. The concentration of 0.01 mol·L -1 PBS solution with a pH value of 6.0 was used as the buffer solution. Rifampicin standard solution was added to the buffer solution. The bias voltage was 0 V. The time-current method was used for testing. The linear relationship between the photocurrent and the logarithm of the concentration of the standard modification solution was obtained.

[0056] (2) Under the same conditions as step (1), the sample solution to be tested is added to the buffer solution, the photocurrent response of the sample solution to be tested is detected, and the concentration of rifampicin in the sample solution to be tested is obtained according to the measured photocurrent intensity using the linear relationship obtained in step (1).

[0057] Example 2

[0058] The preparation method of phenanthro[9,10]pyrazine conjugated microporous polymer specifically comprises the following steps:

[0059] (1) Synthesis of intermediate monomer compound 3: 1.3176 g of 2,7-dibromophenanthrenequinone and 0.5150 g of 1,2,4,5-benzenetetramine tetrahydrochloride were accurately weighed in a molar ratio of 2:1 and placed in a 50 mL round-bottom flask. 50 mL of glacial acetic acid was added and nitrogen was replaced three times. Under nitrogen protection, the mixture was heated to 115 ° C and refluxed for 15 h. After the reaction was completed, the mixture was cooled to room temperature and the suspension was filtered under reduced pressure to obtain a brown-red solid. The solid was then rinsed with 65 ° C hot water three times and 65 ° C hot ethanol three times. Finally, the solid was dried in a vacuum drying oven at 50 ° C for 12 h to obtain the intermediate monomer compound 3.

[0060] (2) Synthesis of CMP-1: 0.0397 g of 1,4-diethynylbenzene and 0.1030 g of intermediate monomer compound 3 were accurately weighed in a molar ratio of 1:1 and added to a 100 mL two-necked flask. 8.2 mg of catalyst tetrakis(triphenylphosphine)palladium and 8.2 mg of copper iodide were added to the reaction vessel B, and nitrogen was replaced three times. 5 mL of the catalyst was added to a 50 mL two-necked flask. N,N-dimethylformamide and 5mL triethylamine were replaced with nitrogen four times, and nitrogen was introduced to deoxygenate for 20 minutes, and then transferred into a 100mL two-necked flask containing the reactants; heated to 88°C, stirred and refluxed under nitrogen protection for 90 hours, and after the reaction was completed, cooled to room temperature; the suspension was filtered under reduced pressure and rinsed and filtered with chloroform, double distilled water, methanol and acetone respectively to remove unreacted monomers or catalyst residues; then Soxhlet extraction was performed with dichloromethane for 72 hours to further purify the polymer; finally, vacuum drying was performed at 70°C for 24 hours to obtain polymer CMP-1.

[0061] Preparation of photoelectric sensors

[0062] Accurately weigh 10 mg of the CMP composite material into 1 mL of a 2% chitosan acetic acid solution. Ultrasonicate for 30 minutes to fully disperse the CMP in the chitosan solution to prepare a suspension. Then, use a pipette to evenly apply 10 μL of the CMP suspension onto the conductive surface of a clean conductive glass. Allow the modified CMP / ITO electrode to air dry or dry under an infrared lamp before use. The ITO electrode used in this example measures 3 cm x 1 cm. After sealing with insulating adhesive, the modified area is 1 cm x 1 cm.

[0063] The prepared CMP / ITO electrode was used for the detection of rifampicin. The specific method was as follows:

[0064] (1) Prepare gradient concentrations of rifampicin standard solutions. A three-electrode system was formed using a CMP / ITO electrode as the working electrode, an Ag-AgCl electrode as the reference electrode, and a platinum wire electrode as the auxiliary electrode. A 10 W blue light source was used as the light source. The concentration of 0.01 mol·L -1 PBS solution with a pH value of 5.5 was used as the buffer solution. Rifampicin standard solution was added to the buffer solution. The bias voltage was 0 V. The time-current method was used for testing. The linear relationship between the photocurrent and the logarithm of the concentration of the standard modification solution was obtained.

[0065] (2) Under the same conditions as step (1), the sample solution to be tested is added to the buffer solution, the photocurrent response of the sample solution to be tested is detected, and the concentration of rifampicin in the sample solution to be tested is obtained according to the measured photocurrent intensity using the linear relationship obtained in step (1).

[0066] Example 3

[0067] The preparation method of phenanthro[9,10]pyrazine conjugated microporous polymer specifically comprises the following steps:

[0068] (1) Synthesis of intermediate monomer compound 3: 1.6470 g of 2,7-dibromophenanthrenequinone and 0.5150 g of 1,2,4,5-benzenetetramine tetrahydrochloride were accurately weighed in a molar ratio of 2.5:1 and placed in a 50 mL round-bottom flask. 50 mL of glacial acetic acid was added and nitrogen was replaced three times. Under nitrogen protection, the mixture was heated to 125 ° C and condensed under reflux for 10 h. After the reaction was completed, the mixture was cooled to room temperature and the suspension was filtered under reduced pressure to obtain a brown-red solid. The solid was then rinsed three times with 75 ° C hot water and three times with 75 ° C hot ethanol. Finally, the solid was placed in a vacuum drying oven at 50 ° C and dried for 12 h to obtain the intermediate monomer compound 3.

[0069] (2) Synthesis of CMP-1: 0.5960 g of 1,4-diethynylbenzene and 0.1030 g of intermediate monomer compound 3 were accurately weighed in a molar ratio of 1.5:1 and added to a 100 mL two-necked flask. 15 mg of catalyst tetrakis(triphenylphosphine)palladium and 15 mg of copper iodide were added to the reaction vessel B and nitrogen was purged three times. 5 mL of N,N-dimethylformamide and 5 mL of triethylamine were added to a 50 mL two-necked flask and nitrogen was purged three times. The mixture was deoxygenated by nitrogen for 25 minutes and then transferred to the 100 mL two-necked flask containing the reactants. The mixture was heated to 95°C and stirred under reflux for 60 hours under nitrogen protection. After the reaction was completed, the mixture was cooled to room temperature. The suspended matter was filtered under reduced pressure and rinsed and filtered to remove unreacted monomers or catalyst residues. The polymer was further purified by Soxhlet extraction with dichloromethane for 90 hours. Finally, the polymer was vacuum dried at 70°C for 24 hours to obtain polymer CMP-1.

[0070] Preparation of photoelectric sensors

[0071] Accurately weigh 10 mg of the CMP composite material into 1 mL of a 2% chitosan acetic acid solution. Ultrasonicate for 30 minutes to fully disperse the CMP in the chitosan solution to prepare a suspension. Then, use a pipette to evenly apply 10 μL of the CMP suspension onto the conductive surface of a clean conductive glass. Allow the modified CMP / ITO electrode to air dry or dry under an infrared lamp before use. The ITO electrode used in this example measures 3 cm x 1 cm. After sealing with insulating adhesive, the modified area is 1 cm x 1 cm.

[0072] The prepared CMP / ITO electrode was used for the detection of rifampicin. The specific method was as follows:

[0073] (1) Prepare gradient concentrations of rifampicin standard solutions. A three-electrode system was formed using a CMP / ITO electrode as the working electrode, an Ag-AgCl electrode as the reference electrode, and a platinum wire electrode as the auxiliary electrode. A 10 W blue light source was used as the light source. The concentration of 0.01 mol·L -1 PBS solution with a pH value of 6.5 was used as the buffer solution. Rifampicin standard solution was added to the buffer solution. The bias voltage was 0 V. The time-current method was used for testing. The linear relationship between the photocurrent and the logarithm of the concentration of the standard modification solution was obtained.

[0074] (2) Under the same conditions as step (1), the sample solution to be tested is added to the buffer solution, the photocurrent response of the sample solution to be tested is detected, and the concentration of rifampicin in the sample solution to be tested is obtained according to the measured photocurrent intensity using the linear relationship obtained in step (1).

[0075] 2. Characterization of CMP-1

[0076] In order to gain a deeper understanding of the chemical composition of the conjugated microporous polymer CMP-1, we characterized the CMP-1 polymer synthesized in Example 1.

[0077] 1. Infrared characterization

[0078] The infrared spectrum of CMP-1 polymer is shown in Figure 1 , it can be seen that CMP-1 is at 3415cm -1 A broad and strong absorption peak appears at 2924cm, which is the stretching vibration of carbon and hydrogen in unsaturated carbon (benzene ring); -1 There is also an absorption peak at 1250-1700cm -1 The vibration absorption peak at 900-450cm is the stretching vibration of the carbon skeleton on the benzene ring; -1 The absorption peak at 2209cm is the out-of-plane bending vibration of the carbon-hydrogen bond on the benzene ring. -1The vibration absorption peak of the triple bond of CMP-1 appears at , indicating that the Sonogashira-Hagihara coupling reaction has occurred. It also shows that the coupling polymerization of CMP occurs through the reaction of bromine and alkyne bonds during the synthesis process. In summary, the above shows that the coupling reaction occurs and the conjugated microporous polymer CMP-1 is successfully synthesized.

[0079] 2. Scanning electron microscopy characterization

[0080] CMP-1 is formed by the polymerization of intermediate monomer compound 3 and 1,4-diethynylbenzene. The benzene rings are connected by two acetylenic bonds. They rotate freely around the acetylenic bonds and form a network structure. Figure 2 The left picture is an overall picture of CMP-1, and the right picture is a partial picture of CMP-1. It can be seen that CMP-1 synthesized from the intermediate monomer and 1,4-diethynylbenzene has a tubular structure, and the outside of the tube has an expanded sponge feeling, indicating a large specific surface area and a high porosity.

[0081] 3. X-ray diffraction characterization

[0082] The X-ray diffraction pattern of CMP-1 polymer can be found in Figure 3 As can be seen, CMP-1 exhibits ordered, crystalline overall characteristics, attributed to a kinetically controlled polymerization reaction. The broad peak of CMP-1 is approximately 25°, corresponding to a d-spacing of 4.5°. While CMP-1 lacks a clear peak in the figure, several relatively broad dispersion fronts appear at 20-45°, suggesting the polymer may have a certain crystalline form. Combined with the previous electron micrographs, CMP-1 exhibits a fluffy, long, and narrow shape.

[0083] 4. Thermogravimetric characterization

[0084] The structure of CMP is composed of benzene ring and thiophene ring connected by carbon-carbon triple bond. Such a structure has a lot of rigidity, so the polymer has good thermal stability, which is also reflected in the thermogravimetric analysis diagram. Figure 4 It can be seen that under a nitrogen atmosphere, the weight loss of the prepared CMP before 300°C is almost zero, with no obvious thermal degradation. Furthermore, when the temperature reaches 500°C, the CMP loses approximately 20% of its weight, with no significant weight loss. The polymer's weight loss during the decomposition process is not severe, indicating that the decomposition of the polymer is not a rapid process. This is also due to its ultra-high thermal stability. In summary, the thermal decomposition temperature and high residual amount of the polymer are satisfactory, indicating that the CMP has good polymerization and long-term chemical and thermal stability.

[0085] 5. XPS characterization

[0086] The XPS spectrum of CMP-1 polymer is shown in Figure 5 It is not difficult to observe from the figure that CMP-1 has obvious peak signals of carbon atoms and nitrogen atoms, which proves that most of the carbon atoms have been integrated into the carbon skeleton. The composite material contains C, N, and O elements. After high-temperature carbonization at 500°C, some carbon atoms escape from the carbon skeleton, but a large part of them is still preserved in CMP-1.

[0087] 6. Solid-state NMR characterization

[0088] The polymer was characterized at the molecular level by solid-state nuclear magnetic resonance spectroscopy. Figure 6 For CMP-1, there are approximately five broad peaks at 150, 130, 120, 75, and 55 ppm. The carbon atoms in the benzene ring can be divided into two categories in the solid-state NMR spectrum: unsubstituted carbon atoms, primarily located at 150, 120, 75, and 55 ppm, and substituted carbon atoms, primarily at 130 ppm. Signal peaks with chemical shifts above 150 ppm are attributed to carbon atoms on the benzene ring. Resonances near 130 ppm are attributed to carbon atoms on the benzene ring that are partially substituted with nitrogen at positions 1, 2, 6, 8, 9, 10, 11, and 13. Peaks around 120 ppm are primarily derived from carbon atoms on the benzene ring. Characteristic resonance peaks at 75 and 55 ppm correspond to the carbon-carbon triple bonds connecting the benzene rings. High peaks can still be seen at the end of the spectrum. These may be resonance peaks from incompletely reacted benzene rings, from benzene rings that cannot react due to steric hindrance, or from unreacted raw materials.

[0089] 7. Specific surface area and pore properties

[0090] According to the BET formula, the BET surface area of ​​CMP-1 is 601.62 m 2 / g, indicating that the polymer has a large surface area. Figure 7 It can be seen that the pore size distribution is mainly concentrated between 2.5 and 15 nm. According to the Saito-Flory method, the CMP is calculated at P / P o = 0.99 The total pore volume is 0.21 cm 3 / g. The nitrogen adsorption / desorption experiment was carried out at 77K and the resulting isothermal adsorption curve was as follows: Figure 8 As shown, in p / p 0 When η = 0, the adsorption isotherm curve shows a sharp increase, indicating the presence of a large number of micropores in the material. The hysteresis loop in the adsorption isotherm curve is likely due to the expansion of the polymer backbone under high nitrogen concentration conditions. These combined results indicate that CMP-1 is a porous composite material with a large surface area.

[0091] The characterization results of CMP-1 synthesized in Examples 1-3 were consistent.

[0092] 3. Performance Testing

[0093] 1. Cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS) characterization of different modified electrodes

[0094] Compound 1 / ITO electrodes and Compound 2 / ITO electrodes were prepared using the same photoelectric sensor preparation method as in Example 1, substituting Compound 1 for CMP-1. Cyclic voltammetry was used to investigate the electrochemical behavior of the modified ITO, Compound 1 / ITO, Compound 2 / ITO, and CMP / ITO electrodes in a 5 mmol / L potassium ferricyanide electrolyte solution. The test was conducted at a scan rate of 0.1 V / s over a potential window of -0.2 V to 0.8 V.

[0095] See the results Figure 9 and Figure 10 ,from Figure 9 As can be seen in the graph, the current responses of the ITO conductive glass electrode, compound 2 / ITO electrode, compound 1 / ITO electrode, and CMP / ITO electrode in potassium ferricyanide electroactive solution increase in sequence, indicating that each material can be modified onto the ITO electrode, and the catalytic activity increases in sequence. Among them, the oxidation peak and reduction peak currents of the CMP / TTO composite electrode are the largest, indicating that the CMP composite effectively increases the effective area of ​​the electrode, accelerates electron transfer efficiency, and enhances catalytic activity.

[0096] Figure 10 Impedance experiments on various modified electrodes investigated the electron transfer capacity of electroactive substances across the electrodes modified with different materials. The larger the semicircle diameter in the high-frequency region, the greater the impedance and the lower the electron transfer capacity. Comparing the semicircle portion of the high-frequency region of the impedance graph, the electrodes were ranked according to their diameters: bare electrode > Compound 2 > Compound 1 > CMP / ITO. Therefore, the order of electron transfer capacity for each electrode follows: CMP / ITO > Compound 1 > Compound 2 > bare electrode. CMP / ITO exhibited the smallest semicircle diameter and the lowest charge and mass transfer resistance compared to the other three electrodes. This indicates that the CMP / ITO composite material has been well modified onto the electrode, enhancing electron transfer capacity.

[0097] 2. Photocurrent response of different modified electrodes

[0098] To investigate the photocurrent response of rifampicin on various modified electrodes, a 2 mg / mL rifampicin solution was prepared and a 0.01 mol / L PBS buffer solution (pH 7) was added as an electrolyte. Rifampicin was detected under illumination using a bare electrode, a Compound 1 / ITO electrode, a Compound 2 / ITO electrode, and a CMP / ITO electrode. The time-current method (iT) was used to measure the photocurrent response and peak current of each electrode, with a bias voltage of 0 V.

[0099] Test results see Figure 11 Comparing the currents at different electrodes in the figure shows that the photocurrent order is: CMP / ITO > Compound 2 / ITO > Compound 1 / ITO. This demonstrates that the CMP / ITO composite material has been well modified onto the electrode, significantly improving its conductivity and boosting its photocurrent response.

[0100] 3. Establishment of standard curve

[0101] According to the optimal experimental conditions of Example 1, the relationship between rifampicin concentration and photocurrent response was studied using the iT method. Figure 12 and 13 It can be seen that the photocurrent response decreases with the increasing concentration of rifampicin, and the photocurrent response is inversely proportional to the rifampicin concentration. -9 ~1.2×10 -5 mol / L, the photocurrent of rifampicin showed a good linear relationship with the concentration, and the linear equation was I = -0.0198x + 1.0 × 10 -6 ,(R 2 =0.9984), detection limit 2.68×10 -9 mol / L. After consulting the literature and comparing with other reports, the CMP / ITO sensor has a good linear range and detection limit for the quantitative determination of rifampicin, and a wide detection range, reflecting good performance.

[0102] 4. Reproducibility and stability

[0103] In order to study the reproducibility and stability of CMP / ITO sensors, the reproducibility and stability of the modified electrodes were studied after long-term storage. The modified electrodes were stored in a refrigerator for 6 days and the modified electrodes were studied under the optimal conditions for 6 days. Figure 14 It can be seen that the peak current on the sixth day has little change compared with the initial peak current value, with a relative standard deviation of 3.7%. Under the same conditions, we also conducted an experimental study on the stability of the sensor. Under the optimal conditions, the modified electrode was measured 11 times in parallel. Figure 15It can be seen that the peak current of this series does not change much, and its relative standard deviation (RSD) is 1.3%. The results show that the sensor has good reproducibility and stability.

[0104] 5. Selectivity and anti-interference

[0105] Under the optimal experimental conditions, we studied the anti-interference and selectivity of CMP for rifampicin. We added 100-fold concentration of ascorbic acid, 250-fold concentration of potassium bromide, 200-fold concentration of sodium nitrite and other interfering substances, as shown in Table 1, to study the changes in the peak current of rifampicin. Figure 16 As can be seen, the peak current of rifampicin did not change significantly under the influence of 15 different concentrations of interfering substances, indicating no significant impact on detection. Under the same conditions, we conducted a study on the selectivity of rifampicin. We compared the peak currents of these 15 interfering substances and CMP with the blank current and found that the current ratio of CMP to rifampicin was much greater than that of other interfering substances. This demonstrates that CMP has good selectivity for rifampicin and high anti-interference ability.

[0106] Table 1 Effects of Interfering Substances

[0107] substance Relative error / % multiple ascorbic acid 0.18％ 100 Potassium bromide -3.77％ 250 Sodium nitrite 4.26％ 200 Potassium iodide 2.31％ 150 uric acid 0.26％ 200 Curcumin -3.93％ 100 Roxithromycin -1.93％ 200 dextrin -0.89％ 100 calcium carbonate 4.32％ 100 sodium nitrate 0.53％ 300 L-Cysteine 0.81％ 200 Tyrosine -4.59％ 300 L-lactic acid 1.25％ 100 Metronidazole 2.21％ 100 Cefazolin 4.97％ 100

[0108] 6. Recovery rate experiment

[0109] In order to further investigate the application capability of conjugated microporous polymer composite materials on actual samples, the prepared CMP / ITO sensor was used to measure the content of rifampicin, thereby inferring the practical application value of the CMP sensor. The sample processing method is as follows:

[0110] Take 10 rifampicin capsules, open them all and place them in a small beaker, accurately weigh 0.15g, dissolve it in a 10mL volumetric flask, dilute to the scale, and test its recovery rate.

[0111] Add the rifampicin tablets to the eye drop buffer, shake well, transfer 1.65 mL to a 10 mL volumetric flask, dilute to the mark, and test its recovery rate.

[0112] The experimental results are shown in Table 2. Within the linear range of rifampicin, the standard addition method was used to further analyze a series of sample solutions at a given concentration. Comparison of these results with those obtained using the method recommended by the Chinese Pharmacopoeia revealed no significant differences between the two methods, demonstrating that the CMP sensor method is stable and reliable and can be used for the determination of rifampicin in real-world samples.

[0113] Table 2 Detection of the recovery rate of rifampicin

[0114]

[0115] The above description is a detailed description of the preferred embodiments of the present invention, but the embodiments are not intended to limit the scope of the patent application of the present invention. Any equivalent changes or modifications completed under the technical spirit suggested by the present invention should fall within the patent scope covered by the present invention.

Claims

1. Phenanthro[9,10]pyrazine conjugated microporous polymer, characterized in that: The conjugated microporous polymer is denoted as CMP-1, and its structure is shown in formula (I):

2. The method for preparing a conjugated microporous polymer according to claim 1, wherein: The intermediate monomer compound 3 is prepared by reacting 2,7-dibromophenanthrenequinone and 1,2,4,5-benzenetetramine tetrahydrochloride, and then the intermediate compound 3 is reacted with 1,4-diethynylbenzene in the presence of a palladium catalyst to undergo a Sonogasihra-Hagihara coupling reaction to obtain the intermediate compound 3. The structure of the intermediate compound 3 is shown in formula (II):

3. The preparation method according to claim 2, characterized in that The specific steps include: (1) Synthesis of intermediate monomer compound 3: 2,7-dibromophenanthrenequinone and 1,2,4,5-benzenetetramine tetrahydrochloride were accurately weighed in a molar ratio of 2 to 2.5:1 and placed in a reaction vessel A. Glacial acetic acid was added and nitrogen was purged several times. Under nitrogen protection, the mixture was heated to 115 to 125°C and refluxed under condensation for 10 to 15 hours. After the reaction was completed, the mixture was cooled to room temperature and the suspension was filtered under reduced pressure to obtain a brown-red solid. The solid was then rinsed with hot water and hot ethanol and finally dried to obtain the intermediate monomer compound 3. (2) Synthesis of CMP-1: 1,4-diethynylbenzene and intermediate monomer compound 3 were accurately weighed in a molar ratio of 1 to 1.5:1 and added to reaction vessel B. Catalysts tetrakis(triphenylphosphine)palladium and copper iodide were added to reaction vessel B and nitrogen was replaced several times. N,N-dimethylformamide and triethylamine were added in a volume ratio of 1:1 to reaction vessel C, nitrogen was replaced several times, nitrogen was introduced to remove oxygen, and the mixture was transferred to reaction vessel B containing the reactants. The mixture was heated to 88 to 95°C and stirred under reflux under nitrogen protection. After the reaction was completed, the mixture was cooled to room temperature. The suspended matter was filtered under reduced pressure, rinsed and filtered to remove unreacted monomers or catalyst residues. The polymer was further purified by Soxhlet extraction with dichloromethane. Finally, the polymer CMP-1 was obtained by vacuum drying.

4. The preparation method according to claim 3, wherein: In step (1), the temperature of the hot water and hot ethanol is 65-75°C.

5. The preparation method according to claim 3, wherein: In step (2), the amount of the catalyst tetrakis(triphenylphosphine)palladium and copper iodide used is 8-15% of the weight of the intermediate monomer compound 3.

6. The preparation method according to claim 3, wherein: The Soxhlet extraction time is 60 to 90 hours.

7. The use of the conjugated microporous polymer according to claim 1, characterized in that: The application is to modify the conjugated microporous polymer CMP-1 on an ITO electrode to obtain a CMP / ITO electrode for the detection of rifampicin.

8. The use of the conjugated microporous polymer according to claim 7, characterized in that: The modification method comprises taking a conjugated microporous polymer CMP-1 composite material into a 2wt% chitosan acetic acid solution, ultrasonically dispersing the CMP in the chitosan solution to prepare a suspension, then using a pipette to transfer the CMP suspension and evenly dripping it onto the conductive surface of the cleaned conductive glass, and then drying the modified CMP / ITO electrode naturally or using an infrared lamp.

9. The use of the conjugated microporous polymer according to claim 7, characterized in that: The method used for the detection of rifampicin is: (1) Prepare a rifampicin standard solution with a gradient concentration, use a CMP / ITO electrode as the working electrode, an Ag-AgCl electrode as the reference electrode, and a platinum wire electrode as the auxiliary electrode to form a three-electrode system, use blue light as the light source, use PBS solution as the buffer solution, add the rifampicin standard solution to the buffer solution, set the bias voltage to 0 V, and use the time-current method to test, and obtain a linear relationship between the photocurrent and the logarithm of the standard modification solution concentration; (2) Under the same conditions as step (1), the sample solution to be tested is added to the buffer solution, the photocurrent response of the sample solution to be tested is detected, and the concentration of rifampicin in the sample solution to be tested is obtained according to the measured photocurrent intensity using the linear relationship obtained in step (1).

10. The use of the conjugated microporous polymer according to claim 9, characterized in that: The concentration of the PBS solution is 0.01 mol·L -1 , pH value is 5.5~6.5.

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