A type of aggregation-induced luminescence charge-type free radical photosensitizer and its preparation method and antibacterial application

Abstract

The present invention discloses a class of aggregation-induced luminescence charge-type free radical photosensitizers and their preparation methods and antibacterial applications, and belongs to the technical field of photosensitizers and antibacterial materials. The present invention introduces a mobile electron donor into the molecular structure of the photosensitizer, constructs a strong charge transfer (CT) state, and suppresses the intermolecular π-π stacking effect of the molecules in the aggregated state, thereby giving the material significant aggregation fluorescence enhancement properties. And introduce an electron acceptor into the molecular structure, thereby strengthening the CT state of the product. In addition, due to the strong degree of distortion between the electron donor-acceptor, it is beneficial to separate the highest occupied orbital and the lowest unoccupied orbital of the molecule, thereby achieving a smaller singlet-triplet energy level difference, promoting the excited singlet energy gap to cross to the triplet state to achieve efficient ROS generation. At the same time, due to the limited molecular aggregation motion, non-radiative excitation energy is effectively suppressed, prompting energy to dissipate energy in the radiation transition pathway, and fluorescence efficiency is increased.

Description

Technical Field

[0001] The present invention belongs to the technical field of photosensitizers and antibacterial materials, and in particular relates to an aggregation-induced luminescence charge-type free radical photosensitizer, a preparation method thereof, and antibacterial applications. Background Art

[0002] Fluorescence imaging-guided photodynamic therapy (PDT) has attracted significant attention in the clinical treatment of diseases due to its outstanding therapeutic advantages, including non-invasiveness, low drug resistance, real-time visualization, and excellent spatiotemporal selectivity. As a key component of PDT, the development of efficient and multifunctional photosensitizers (PS) has become a key research topic. Commercial photosensitizers (such as porphyrins, methylene blue, and rose Bengal derivatives) possess a planar, rigid molecular structure. While these agents exhibit excellent ROS scavenging efficiency, high molar absorptivity, and low cytotoxicity, their rigid molecular structure also induces intermolecular π-π stacking, which readily aggregates in physiological environments. This leads to fluorescence quenching and reduced ROS scavenging efficiency, severely impacting clinical disease diagnosis and treatment. Charged photosensitizers, due to their superior targeting of mitochondria and Gram-positive bacteria and their ability to efficiently generate reactive oxygen species (ROS), have attracted increasing attention in the field of PDT. However, the strong intramolecular charge transfer and intermolecular dipole-dipole interactions of charged photosensitizers can still lead to fluorescence quenching and reduced ROS scavenging efficiency. Furthermore, most commercial photosensitizers generate singlet oxygen and are highly oxygen-dependent, making it difficult for them to generate ROS efficiently and sustainably in hypoxic environments. Therefore, developing novel photosensitizer material systems with enhanced fluorescence aggregation and ROS efficiency, coupled with low oxygen dependence, is of great research significance for clinical tumor therapy and antibacterial research.

[0003] Aggregation-induced emission (AIE) photosensitizers have the unique advantage of enhancing fluorescence and ROS production through aggregation, and are expected to replace traditional commercial photosensitizers and promote the development of photodynamic therapy for cancer and antibacterial applications. However, existing AIE photosensitizers still suffer from the inability to generate ROS efficiently and sustainably in hypoxic environments.

[0004] Therefore, a photosensitizer with low oxygen dependence and high aggregation-induced fluorescence efficiency and ROS efficiency is urgently needed to solve the above problems. Summary of the Invention

[0005] In order to solve the above technical problems, the present invention proposes a class of aggregation-induced luminescence charge-type free radical photosensitizers and their preparation methods and antibacterial applications.

[0006] To achieve the above objectives, the present invention provides the following technical solutions:

[0007] The present invention provides a class of aggregation-induced luminescence charge-type free radical photosensitizers, the general structural formula of which is:

[0008]

[0009] In the formula, R1 is hydrogen or an aromatic condensed ring, R2 is benzothiadiazole, a benzothiadiazole derivative or a carbon-carbon double bond, R3 is an alkyl group, and X- is an anion pair.

[0010] The present invention introduces a mobile electron donor into the molecular structure of the photosensitizer, constructs a strong charge transfer (CT) state, and suppresses the intermolecular π-π stacking effect of the molecules in the aggregated state, thereby giving the material significant aggregation fluorescence enhancement properties. And introduces an electron acceptor into the molecular structure, thereby strengthening the CT state of the product. In addition, due to the strong degree of distortion between the electron donor and the acceptor, it is beneficial to the separation of the highest occupied molecular orbital (HOMO) and the lowest unoccupied molecular orbital (LUMO), thereby achieving a smaller singlet-triplet energy level difference (ΔEst), promoting the excited singlet energy gap crossing (ISC) to the triplet state to achieve efficient ROS generation. At the same time, due to the limited molecular aggregation motion, non-radiative excitation energy is effectively suppressed, prompting energy to dissipate energy in the radiation transition pathway, and the fluorescence efficiency is increased.

[0011] The aggregation-induced luminescence charge-type free radical photosensitizer provided by the present invention has high fluorescence quantum efficiency and ROS generation ability, and has good application prospects in the field of Gram-positive bacteria-specific fluorescence recognition and photodynamic antibacterial.

[0012] Preferably, the aromatic fused ring is one of (a)-(d); the structural formulas of (a)-(d) are as follows:

[0013]

[0014] Among them, "*" represents the site of connection with the mother nucleus.

[0015] Furthermore, the R1 is a pyrene-condensed ring (d).

[0016] Furthermore, the R2 is benzothiadiazole.

[0017] Preferably, R3 is any one of alkyl groups with a carbon chain number ≤ 18.

[0018] Preferably, R3 is one of methyl, ethyl, propyl, butyl, isobutyl, tert-butyl, and hexyl; more preferably, it is methyl.

[0019] Preferably, the X - It is one of iodide ion, bromide ion, hydroxide ion, tetrafluoroborate ion, nitrate ion, sulfate ion, and hexafluorophosphate ion.

[0020] Furthermore, the X - For iodide ion.

[0021] The present invention provides a method for preparing an aggregation-induced luminescence charge-type free radical photosensitizer according to the above technical solution, comprising the following steps: using a triphenylamine derivative and 1-pyreneboronic acid or 4,7-dibromo-5,6-difluoro-benzothiadiazole, a triphenylamine derivative and 4-formylphenylboronic acid as raw materials, obtaining an intermediate product through a Suzuki coupling reaction; and subjecting the obtained intermediate product and a charge-type pyridine derivative to an Aldol dehydration condensation reaction in the presence of a catalyst to obtain the aggregation-induced luminescence charge-type free radical photosensitizer.

[0022] Preferably, the molar ratio of the triphenylamine derivative to 1-pyreneboronic acid is 2:5; the molar ratio of the 4,7-dibromo-5,6-difluoro-benzothiadiazole, the triphenylamine derivative and 4-formylphenylboronic acid is 5:6:3.

[0023] Furthermore, the triphenylamine derivative includes 4-[N,N-bis(4-bromophenyl)amino]benzaldehyde or triphenylamine boric acid.

[0024] Furthermore, the charged pyridine derivative includes 1,4-dimethylpyridinium-1-iodide.

[0025] Furthermore, the molar ratio of the intermediate product to the charged pyridine derivative is 5:7.

[0026] Furthermore, the catalyst is piperidine; the usage ratio of the piperidine to the charged pyridine derivative is 10 μL:0.7 mmol.

[0027] Preferably, the reaction time of the Suzuki coupling reaction and the Aldol dehydration condensation reaction is 12 h.

[0028] The present invention provides the use of the aggregation-induced luminescence charge-type free radical photosensitizer described in the above technical solution in the preparation of a drug for specific fluorescent identification of Gram-positive bacteria.

[0029] The present invention provides the use of the aggregation-induced luminescence charge-type free radical photosensitizer described in the above technical solution in the field of preparing photodynamic antibacterial drugs.

[0030] Compared with the prior art, the present invention has the following advantages and technical effects:

[0031] (1) The aggregation-induced luminescence charge-type free radical photosensitizer provided by the present invention overcomes the aggregation fluorescence quenching effect and the problem of decreased ROS efficiency caused by aggregation in existing commercial photosensitizers.

[0032] (2) The synthesis method of the aggregation-induced luminescence charge-type free radical photosensitizer provided by the present invention is simple, the raw materials are easily available, the yield is high, and the obtained material structure is stable.

[0033] (3) The aggregation-induced luminescence charge-type free radical photosensitizer provided by the present invention has a specific fluorescence recognition effect on Gram-positive bacteria.

[0034] (4) The aggregation-induced luminescence charge-type free radical photosensitizer provided by the present invention has good photodynamic antibacterial effect on Escherichia coli, Staphylococcus aureus and methicillin-resistant Staphylococcus aureus. BRIEF DESCRIPTION OF THE DRAWINGS

[0035] The accompanying drawings, which constitute part of this application, are intended to provide a further understanding of this application. The exemplary embodiments and descriptions of this application are intended to explain this application and do not constitute an improper limitation on this application. In the accompanying drawings:

[0036] Figure 1 The UV absorption spectrum and fluorescence spectrum of the photosensitizer prepared in Example 1-2 in dichloromethane solvent;

[0037] Figure 2 The fluorescence emission spectra of the photosensitizer prepared in Example 1-2 in a dimethyl sulfoxide / toluene mixed solvent as the toluene content increases;

[0038] Figure 3 The performance of the photosensitizer prepared in Example 1-2 in generating ROS under white light irradiation conditions;

[0039] Figure 4 The performance of the photosensitizer prepared in Example 1-2 in generating singlet oxygen under white light irradiation;

[0040] Figure 5 The photosensitizer prepared in Example 1-2 generates superoxide anion free radical reactive oxygen species under white light irradiation conditions;

[0041] Figure 6 The photosensitizer prepared in Example 1-2 generates hydroxyl radicals and reactive oxygen species under white light irradiation conditions;

[0042] Figure 7 This is a diagram showing the fluorescence staining effect of pTPAPy prepared in Example 1 on Escherichia coli;

[0043] Figure 8 This is a diagram showing the fluorescence staining effect of pTPAPy prepared in Example 1 on Staphylococcus aureus;

[0044] Figure 9 This is a fluorescence staining effect diagram of pTPAPy prepared in Example 1 on methicillin-resistant Staphylococcus aureus;

[0045] Figure 10 The photodynamic antibacterial effect of pTPAPy at different concentrations on Escherichia coli is shown;

[0046] Figure 11 The photodynamic antibacterial effect of pTPAPy at different concentrations on Staphylococcus aureus is shown;

[0047] Figure 12 The photodynamic antibacterial effect of different concentrations of pTPAPy on methicillin-resistant Staphylococcus aureus. DETAILED DESCRIPTION

[0048] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of the present invention.

[0049] In order to make the above-mentioned objects, features and advantages of the present invention more obvious and easy to understand, the present invention is further described in detail below with reference to the accompanying drawings and specific embodiments.

[0050] The room temperature in the embodiments of the present invention refers to "25±2°C".

[0051] Unless otherwise specified, the raw materials in the examples of the present invention were purchased from commercial sources.

[0052] Example 1

[0053] An aggregation-induced luminescence charge-type free radical photosensitizer, the structural formula of which is:

[0054]

[0055] The synthetic route is:

[0056]

[0057] The specific preparation process is:

[0058] (1) Preparation of pTPA-CHO

[0059] 4-[N,N-bis(4-bromophenyl)amino]benzaldehyde (858 mg, 2 mmol), 1-pyreneboronic acid (1.23 g, 5 mmol), and tetrakistriphenylphosphine palladium (Pd(PPh3)4, 46 mg) were placed in a two-necked flask and filled with N2. Under N2 protection, tetrahydrofuran (THF, 20 mL) and K2CO3 aqueous solution (2 M, 8 mL) were injected into the reaction vessel and refluxed for 12 hours. After completion of the reaction, the reaction solution was extracted three times with dichloromethane (DCM) and column chromatography was performed to obtain pTPA-CHO (734 mg), a yellow powder.

[0060] The characterization data of the obtained pTPA-CHO are: 1 H NMR (400MHz, d-DMSO) δ (ppm): 9.86 (s, 1H), 8.39-8.22 (m, 14H), 8.10-8.07 (t, 4H), 7.88 (d, 2H), 7.74 (d, 4H), 7.52 (d, 4H), 7.25 (d, 2H).

[0061] (2) Preparation of pTPAPy

[0062] pTPA-CHO (337 mg, 0.5 mmol) and 1,4-dimethylpyridinium-1-iodide (168 mg, 0.7 mmol) were dissolved in a mixture of THF (4 mL) and methanol (12 mL). 10 μL of pyridine was then added and the mixture was refluxed for 12 h. After the mixture cooled, the solvent was evaporated and the mixture was extracted three times with DCM. The DCM was then evaporated and the resulting product was placed in petroleum ether and refluxed overnight to obtain pTPAPy (235 mg), a red powder.

[0063] The characterization data of the obtained pTPAPy are: 1 H NMR (400MHz, d-DMSO) δ = 8.81 (d, 2H), 8.41-8.10 (m, 21H), 7.80-7.73 (m, 6H), 7.50 (d, 4H), 7.34 (m, 3H).

[0064] Example 2

[0065] An aggregation-induced luminescence charge-type free radical photosensitizer, the structural formula of which is:

[0066]

[0067] The synthetic route is:

[0068]

[0069] The specific preparation process is:

[0070] (1) Preparation of TPAFBZ-Br

[0071] 4,7-Dibromo-5,6-difluoro-benzothiadiazole (5 mmol, 1.64 g), triphenylamine boronic acid (6 mmol, 1.73 g), and Pd(PPh3)4 (116 mg) were placed in a two-necked flask. N2 was then introduced. Under N2 protection, THF (20 mL) and a 2M aqueous K2CO3 solution (8 mL) were injected into the flask. The reaction was refluxed for 12 h. After completion of the reaction, the reaction solution was extracted three times with DCM and purified by column chromatography to obtain TPAFBZ-Br (734 mg), a yellow powder.

[0072] (2) Preparation of TPAFBZ-CHO

[0073] TPAFBZ-Br (2 mmol, 986 mg), 4-formylphenylboronic acid (3 mmol, 450 mg), and Pd(PPh3)4 (46 mg) were placed in a two-necked flask. N2 was introduced, and under N2 protection, THF (20 mL) and a 2M K2CO3 aqueous solution (8 mL) were injected into the flask. The reaction was refluxed for 12 h. After completion of the reaction, the reaction solution was extracted three times with DCM and column chromatography was performed to obtain TPAFBZ-CHO (738 mg), a light red powder.

[0074] The characterization data of the obtained TPAFBZ-CHO are: 1 H NMR (400MHz, d-DMSO) δ = 10.13 (s, 1H), 8.14-8.03 (m, 4H), 7.76 (d, 2H), 7.41-7.15 (m, 12H).

[0075] (3) Preparation of TPAFBZPy

[0076] TPABZ-CHO (259 mg, 0.5 mmol) and 1,4-dimethylpyridinium-1-iodide (168 mg, 0.7 mmol) were dissolved in THF (4 mL) and methanol (12 mL), followed by the addition of 10 μL of piperidine and reflux for 12 h. After the mixture cooled, the solvent was evaporated and extracted three times with DCM. The DCM was then evaporated and the resulting product was placed in petroleum ether and refluxed overnight to obtain TPAFBZPy (287 mg), a black powder.

[0077] The characterization data of the obtained TPAFBZPy are: 1 H NMR (400MHz, d-DMSO) δ = 8.92 (d, 2H), 8.30 (d, 1H), 8.15-7.97 (m, 3H), 7.77-7.75 (m, 4H), 7.41-7.39 (m, 6H), 7.17-7.15 (d, 8H), 4.29 (s, 3H).

[0078] Figure 1 The UV absorption spectrum and fluorescence spectrum of the photosensitizer prepared in Example 1-2 in dichloromethane solvent. Figure 1 As can be seen from the figure, the maximum absorption peaks of pTPAPy and TPAFBZPy are at 520 nm and 428 nm, respectively, while the maximum fluorescence peaks of pTPAPy and TPAFBZPy are at 665 nm and 643 nm, respectively. This indicates that pTPAPy has longer absorption and fluorescence wavelengths than TPAFBZPy, preliminarily suggesting that the intramolecular charge transfer effect of pTPAPy is stronger than that of TPAFBZPy.

[0079] Figure 2 The fluorescence emission spectra of the photosensitizer (10 μM) prepared in Example 1-2 in a dimethyl sulfoxide / toluene mixed solvent are shown as the toluene content increases, where (A) is pTPAPy and (B) is TPAFBZPy. Figure 2 As can be seen, the photosensitizers prepared in Examples 1-2 exhibit weak fluorescence in pure dimethyl sulfoxide (DMSO). With the addition of the poor solvent toluene, fluorescence gradually increases. When the toluene content is increased to 90%, the fluorescence intensity reaches its peak, demonstrating that both pTPAPy and TPAFBZPy photosensitizers exhibit aggregation-induced emission.

[0080] The photosensitizer (2.5 μM) prepared in Example 1-2 was monitored using H2DCF-DA (5 μM) fluorescent probe under white light (the power of the white light lamp was 50 mW / cm 2 ) irradiation to produce ROS performance, the results are shown in Figure 3 . Figure 3 The performance of the photosensitizer prepared in Example 1-2 in generating ROS under white light irradiation, wherein (A) is pTPAPy and (B) is TPAFBZPy. Figure 3 It can be seen that the photosensitizer prepared in Example 1-2 significantly improves the fluorescence intensity of the H2DCF-DA probe under white light irradiation. pTPAPy enhances the fluorescence of the H2DCF-DA probe by 26 times, while TPAFBZPy enhances the fluorescence of the H2DCF-DA probe by 24.6 times, indicating that both pTPAPy and TPAFBZPy can effectively generate ROS.

[0081] Using ABDA (20 μM) absorption probe, the photosensitizer (2.0 μM) prepared in Example 1-2 was monitored under white light (the power of the white light lamp was 50 mW / cm 2 ) irradiated with singlet oxygen species, the results are shown in Figure 4 . Figure 4The performance of the photosensitizer prepared in Example 1-2 in generating singlet oxygen under white light irradiation, wherein (A) is pTPAPy and (B) is TPAFBZPy. Figure 4 It can be seen that under white light irradiation, the absorption intensity of the ABDA probe decreased significantly when the photosensitizer prepared in Example 1-2 was irradiated with white light, and the rate at which the absorption intensity of the ABDA probe decreased with pTPAPy was significantly faster than that with TPAFBZPy, indicating that compared with TPAFBZPy, the pTPAPy photosensitizer has a more efficient singlet oxygen generation ability.

[0082] Using DHR123 (1.0 μM) fluorescent probe, the photosensitizer (2.0 μM) prepared in Example 1-2 was monitored under white light (the power of the white light lamp was 50 mW / cm 2 ) produces superoxide anion radicals under irradiation, and the results are shown in Figure 5 . Figure 5 The photosensitizer prepared in Example 1-2 generates superoxide anion radicals under white light irradiation, wherein (A) is pTPAPy and (B) is TPAFBZPy. Figure 5 It can be seen that the photosensitizer prepared in Example 1-2 significantly improves the fluorescence intensity of the DHR123 probe under white light irradiation. pTPAPy enhances the fluorescence of the DHR123 probe by 54 times, while TPAFBZPy enhances the fluorescence of the DHR123 probe by 47 times, indicating that both pTPAPy and TPAFBZPy can effectively generate superoxide anion free radical reactive oxygen species.

[0083] HPF (5.0 μM) fluorescence probe was used to monitor the photosensitizer (2.0 μM) prepared in Example 1-2 under white light (the power of the white light lamp was 50 mW / cm 2 ) produces hydroxyl radicals under irradiation, and the results are shown in Figure 6 . Figure 6 The photosensitizer prepared in Example 1-2 generates hydroxyl radicals under white light irradiation. Figure 6 It can be seen that the photosensitizer prepared in Example 1-2 significantly improves the fluorescence intensity of the HPF probe under white light irradiation. HPF enhances the fluorescence of the HPF probe by 257 times, while TPAFBZPy enhances the fluorescence of the HPF probe by 57 times, indicating that compared with TPAFBZPy, the pTPAPy photosensitizer has a more efficient ability to generate hydroxyl radical reactive oxygen species.

[0084] Figure 7 This is the fluorescence staining effect of pTPAPy (10.0 μM) prepared in Example 1 on Escherichia coli (Gram-negative bacteria). Figure 7It can be seen that the pTPAPy photosensitizer cannot enter E. coli and is only on the periphery of the bacteria, indicating that the pTPAPy photosensitizer cannot fluorescently stain E. coli.

[0085] Figure 8 This is the fluorescence staining effect of pTPAPy (10.0 μM) prepared in Example 1 on Staphylococcus aureus (Gram-positive bacteria). Figure 8 It can be seen that the pTPAPy photosensitizer can quickly enter Staphylococcus aureus, indicating that the pTPAPy photosensitizer can specifically fluorescently stain Staphylococcus aureus.

[0086] Figure 9 This is the fluorescence staining effect of pTPAPy (10.0 μM) prepared in Example 1 on methicillin-resistant Staphylococcus aureus (drug-resistant bacteria). Figure 9 It can be seen that the pTPAPy photosensitizer can quickly enter the methicillin-resistant Staphylococcus aureus, indicating that the pTPAPy photosensitizer can specifically fluorescently stain methicillin-resistant Staphylococcus aureus.

[0087] The pTPAPy prepared in Example 1 was dissolved in dimethyl sulfoxide to obtain pTPAPy culture solutions of different concentrations (0, 0.125 μM, 0.25 μM, 0.5 μM, 1 μM, 1.25 μM, 2.5 μM, 5 μM, 10 μM, and 20 μM). The pTPAPy culture solutions of 0, 5 μM, 10 μM, and 20 μM were used to culture the cells under no light and light conditions (white light power of 50 mW / cm 2 ) and observed the survival of E. coli after 10 minutes. The results are shown in Figure 10 The pTPAPy culture medium with concentrations of 0, 0.125μM, 0.25μM, 0.5μM, and 1μM was used under no light and light conditions (white light power of 50mW / cm 2 ) and the survival of Staphylococcus aureus was observed after 10 minutes. Figure 11 The pTPAPy culture medium with concentrations of 0, 1.25μM, 2.5μM, 5μM, and 10μM was used under no light and light conditions (white light power of 50mW / cm 2 ) and cultured methicillin-resistant Staphylococcus aureus under the condition of 10 min. The survival of methicillin-resistant Staphylococcus aureus was observed. The results are shown in Figure 12 .

[0088] Figure 10 The photodynamic antibacterial effect of different concentrations of pTPAPy on Escherichia coli is shown in Figure 2. Figure 10It can be seen that with the increase of the culture concentration of pTPAPy photosensitizer, Escherichia coli can be basically killed after irradiation with white light, indicating that pTPAPy photosensitizer has a good photodynamic antibacterial effect on Escherichia coli.

[0089] Figure 11 The photodynamic antibacterial effect of pTPAPy at different concentrations on Staphylococcus aureus is shown in Figure 2. Figure 11 It can be seen that with the increase of the culture concentration of pTPAPy photosensitizer, Staphylococcus aureus can be basically killed after white light irradiation, indicating that pTPAPy photosensitizer has a good photodynamic antibacterial effect on Staphylococcus aureus.

[0090] Figure 12 The photodynamic antibacterial effect of different concentrations of pTPAPy on methicillin-resistant Staphylococcus aureus is shown in Figure 2. Figure 12 It can be seen that with the increase of the culture concentration of pTPAPy photosensitizer, the methicillin-resistant Staphylococcus aureus can be basically killed after irradiation with white light, indicating that pTPAPy photosensitizer has a good photodynamic antibacterial effect on methicillin-resistant Staphylococcus aureus.

[0091] The above are merely preferred embodiments of the present application, but the scope of protection of the present application is not limited thereto. Any changes or substitutions that can be easily conceived by a person skilled in the art within the technical scope disclosed in this application should be included in the scope of protection of the present application. Therefore, the scope of protection of the present application should be based on the scope of protection of the claims.

Claims

1. A type of aggregation-induced emission charge-type free radical photosensitizer, characterized in that: Having the structural formula shown in Formula I or Formula II; Formula I, Formula II; In formula I, R1 is an aromatic fused ring, R2 is a carbon-carbon double bond, R3 is an alkyl group, and X - For anion pairs.

2. The aggregation-induced emission charge-type free radical photosensitizer according to claim 1, characterized in that: The aromatic fused ring is one of (a)-(d); the structural formulas of (a)-(d) are as follows: 。 3. The aggregation-induced emission charge-type free radical photosensitizer according to claim 1, characterized in that: The R3 is any one of the alkyl groups with a carbon chain number ≤ 18.

4. The aggregation-induced emission charge-type free radical photosensitizer according to claim 3, characterized in that: The R3 is one of methyl, ethyl, propyl, butyl, isobutyl, tert-butyl, and hexyl.

5. The aggregation-induced emission charge-type free radical photosensitizer according to claim 1, characterized in that: The X - It is one of iodide ion, bromide ion, hydroxide ion, tetrafluoroborate ion, nitrate ion, sulfate ion, and hexafluorophosphate ion.

6. A method for preparing the aggregation-induced emission charge-type free radical photosensitizer according to any one of claims 1 to 5, characterized in that: The following steps are involved: A triphenylamine derivative and 1-pyreneboronic acid or 4,7-dibromo-5,6-difluoro-benzothiadiazole, a triphenylamine derivative and 4-formylphenylboronic acid are used as raw materials, and an intermediate product is obtained through a Suzuki coupling reaction; the obtained intermediate product and a charged pyridine derivative are subjected to an Aldol dehydration condensation reaction under the action of a catalyst to obtain the aggregation-induced emission charged free radical photosensitizer.

7. The preparation method according to claim 6, characterized in that The molar ratio of the triphenylamine derivative to 1-pyreneboronic acid is 2:5; the molar ratio of the 4,7-dibromo-5,6-difluoro-benzothiadiazole, the triphenylamine derivative and 4-formylphenylboronic acid is 5:6:

3.

8. The preparation method according to claim 6, characterized in that The reaction time of the Suzuki coupling reaction and the Aldol dehydration condensation reaction is 12 h.

9. Use of the aggregation-induced emission charge-type free radical photosensitizer according to any one of claims 1 to 5 in the preparation of a drug for specific fluorescent recognition of Gram-positive bacteria.

10. Use of the aggregation-induced emission charge-type free radical photosensitizer according to any one of claims 1 to 5 in the preparation of photodynamic antibacterial drugs.

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