A binuclear metal ruthenium photocatalyst and its preparation method and application

Abstract

The present invention belongs to the field of pharmaceutical chemistry technology, and specifically relates to a binuclear ruthenium photocatalyst, its preparation method, and application. The present invention discloses a novel tridentate Ru(II) complex for antibacterial purposes. The present invention discloses a binuclear ruthenium complex (see the structural formula below) that has a photocatalytic therapeutic effect against Staphylococcus aureus (S. aureus) and exhibits proliferation inhibition (MIC) against Staphylococcus aureus under light conditions. 90 6.25μM), and can generate superoxide anions and singlet oxygen under light conditions, and has photocatalytic oxidation ability on NADH / NADPH in bacteria. This is of great significance for the research of binuclear ruthenium complex antibacterial drugs and provides new ideas for the clinical development of binuclear ruthenium complex antibacterial photocatalytic drugs or antibacterial metal photosensitizers. #imgabs0#

Description

Technical Field

[0001] The present invention belongs to the technical field of pharmaceutical chemistry, and in particular relates to a binuclear metal ruthenium photocatalyst and a preparation method and application thereof. Background Art

[0002] Bacterial infections pose a serious threat to human health. The abuse and misuse of antibiotics have led to a surge in multidrug-resistant bacteria. Therefore, there is an urgent need to develop efficient and safe antibacterial agents that can replace traditional antibiotics to combat bacterial infections. Photodynamic therapy (PDT) is an emerging cancer treatment method that has emerged in recent years and is now gradually being used in antibacterial treatment. Antibacterial photodynamic therapy (aPDT) is a promising antibacterial strategy. Its main principle is that photosensitizers (PSs) generate reactive oxygen species (ROS) under light conditions. By generating toxic reactive oxygen species (ROS) to destroy cell membranes, bacteria are inactivated, which can minimize bacterial resistance and systemic toxic side effects. Based on the different photochemical reaction mechanisms of ROS generation, PDT can be divided into two types: Type I and Type II. In type I PDT, the photosensitizer in an excited state excited by light eventually reacts with intracellular substrates through an electron transfer pathway to produce superoxide anions (O2 .- ) and hydroxyl radicals (OH . ); In type II PDT, the excited photosensitizer transfers energy between the surrounding oxygen and produces singlet oxygen ( 1 O2). It is not difficult to see that photosensitizer is the core of the entire photodynamic therapy process.

[0003] Currently, photosensitizers used in antitumor applications primarily include organic photosensitizers (such as porphyrins, CE6, and phthalocyanines) and inorganic metal complex photosensitizers. Reports on photosensitizers for antibacterial applications are even rarer. The design and synthesis of photosensitizers have long been a research focus. For example, in the case of antitumor photosensitizers, the vast majority of current research on inorganic photosensitizers focuses on synthesizing metal photosensitizers using transition metals ruthenium (Ru) and iridium (Ir) as metal centers coordinated with organic ligands, with ruthenium complexes being the most widely studied. Cationic Ru(II) complexes with bidentate or tridentate ligands to form transition metal complexes with octahedral d6 geometry hold great promise as PDT agents. The first inorganic photosensitizer approved for clinical trials was the ruthenium-centered metal complex TLD-1433. However, bidentate Ru(II) complexes that have demonstrated promising activity in PDT applications are currently the only ones with bidentate coordination. Tridentate Ru(II) compounds have limited their application due to their poor optical properties and bioactivity. Compared to bidentate Ru(II) complexes, tridentate Ru(II) complexes have a defined geometry that avoids enantiomer formation, resulting in higher purity of tridentate Ru(II) complexes. Therefore, rational design of these complexes to develop clinically applicable photosensitizers with higher purity, lower dark toxicity, higher phototoxicity, and greater selectivity and targeting is of great significance.

[0004] Reduced nicotinamide adenine dinucleotide (NADH) and reduced nicotinamide adenine dinucleotide phosphate (NADPH) are essential coenzymes involved in energy metabolism in living cells. They play a crucial role in intracellular metabolic activities such as the tricarboxylic acid cycle, glycolysis, lipid synthesis, and cholesterol synthesis. Selective induction of NADH / NADPH oxidation in bacteria can cause intracellular redox imbalance, leading to bacterial necrosis and apoptosis. This could serve as a novel approach for antibacterial photocatalytic therapy.

[0005] In summary, it can be seen that it is of great significance to study the antibacterial properties of novel tridentate Ru(II) complexes by utilizing the mechanism of inducing NADH / NADPH oxidation. Summary of the Invention

[0006] In order to overcome the above-mentioned deficiencies of the prior art, the primary purpose of the present invention is to provide a binuclear metal ruthenium photocatalyst.

[0007] The second object of the present invention is to provide a method for preparing the above-mentioned binuclear metal ruthenium photocatalyst.

[0008] The third object of the present invention is to provide an application of the binuclear ruthenium photocatalyst. The binuclear ruthenium photocatalyst has a strong photocatalytic therapeutic effect on Staphylococcus aureus (S. aureus).

[0009] The first object of the present invention is achieved by the following technical solutions:

[0010] A binuclear ruthenium complex, the structure of which is shown below:

[0011]

[0012] The above-mentioned second object of the present invention is achieved through the following technical solutions:

[0013] The method for preparing the binuclear ruthenium complex described in the first invention object comprises the following steps:

[0014] S1, dissolving 2,2':6',2"-terpyridine and ruthenium (III) chloride hydrate in an organic solvent, heating and refluxing to generate a precursor compound Ru(tpy)Cl3;

[0015] S2, first dissolving the precursor compounds Ru(tpy)Cl3 and 4'-bromo-2,2':6',2"-terpyridine from step S1 in an organic solvent, heating and refluxing the mixture, and then performing ion exchange with ammonium hexafluorophosphate to generate a ruthenium complex [Ru(tpy)(tpy-Br)](PF6)2;

[0016] S3. Dissolve the ruthenium complex [Ru(tpy)(tpy-Br)](PF6)2, 5,6-difluoro-4,7-bis(5-(trimethyltin-2-yl)thiophene)benzo[c][1,2,5]thiadiazole and tetrakis(triphenylphosphine)palladium prepared in step S2 in an organic solvent, and react with stirring under the protection of an inert gas to obtain a binuclear ruthenium complex.

[0017] The present invention adopts a strategy of complex post-modification and utilizes SUZKI coupling to successfully synthesize and purify a binuclear metal ruthenium complex, which cannot be synthesized by traditional complex pre-modification synthesis technology.

[0018] Preferably, in step S1, the heating reflux reaction is carried out at 75-95°C for 2-5 hours; in step S2, the heating reflux reaction is carried out at 75-95°C for 2-4 hours. Furthermore, in both steps S1 and S2, the heating reflux reaction is carried out at 85°C for 3 hours.

[0019] Preferably, in step S3, the stirring reaction is carried out at 100-135° C. for 18-24 hours. Further, the stirring reaction is carried out at 115° C. for 20 hours.

[0020] Preferably, in step S1, the molar ratio of the 2,2':6',2"-terpyridine to ruthenium (III) chloride hydrate is 1:1.2.

[0021] Preferably, in step S2, the molar ratio of the precursor Ru(tpy)Cl3 to 4'-bromo-2,2':6',2"-terpyridine is 1:1.02.

[0022] Preferably, in step S3, the molar ratio of 5,6-difluoro-4,7-bis(5-(trimethyltinyl)thiophen-2-yl)benzo[c][1,2,5]thiadiazole, [Ru(tpy)(tpy-Br)](PF6)2, and tetrakis(triphenylphosphine)palladium is 1:2:0.1.

[0023] Preferably, the organic solvent described in steps S1 and S2 includes but is not limited to ethanol.

[0024] Preferably, the organic solvent described in step S3 includes but is not limited to toluene / N,N-dimethylformamide (3:1).

[0025] The third object of the present invention is achieved by the following technical solutions:

[0026] The first invention object is to use the binuclear metal ruthenium complex in the preparation of antibacterial photocatalytic drugs.

[0027] The present invention has been found through research that the binuclear ruthenium complex described in the first invention purpose has the ability to generate superoxide anions and singlet oxygen after illumination, and has obvious photocatalytic oxidation ability for NADH and NADPH; and has a strong growth inhibition ability against Staphylococcus aureus under illumination conditions; as a new type of binuclear ruthenium photocatalyst, it is expected to be used to develop into a high-efficiency and low-toxic antibacterial photocatalytic drug or antibacterial photosensitizer.

[0028] Preferably, the antibacterial photocatalytic drug is an anti-Staphylococcus aureus photocatalytic drug.

[0029] The present invention also provides an antibacterial photocatalytic drug or antibacterial metal photosensitizer, which uses the binuclear metal ruthenium complex described in the first invention purpose as the main active ingredient.

[0030] Preferably, the drug or photosensitizer further comprises a pharmaceutically acceptable carrier and / or excipient. That is, the drug or photosensitizer comprises a binuclear metal ruthenium complex as the main active ingredient, mixed with a pharmaceutically acceptable carrier and / or excipient to form a composition, and then prepared into a clinically acceptable dosage form.

[0031] Furthermore, the excipient refers to diluents, adhesives, lubricants, disintegrants, solubilizers, stabilizers and other pharmaceutical matrices that can be used in the pharmaceutical field.

[0032] Furthermore, the carrier is an acceptable functional pharmaceutical excipient in the pharmaceutical field, including surfactants, suspending agents, emulsifiers and some new pharmaceutical polymer materials, such as cyclodextrin, chitosan, polylactic acid (PLA), polyglycolic acid-polylactic acid copolymer (PLGA), hyaluronic acid, etc.

[0033] Furthermore, the present invention has no particular limitation on the dosage form of the above-mentioned drugs or photosensitizers, and the drugs or photosensitizers can be prepared into tablets, capsules, suppositories, powder injections, etc., which are well known to those skilled in the art. The prepared preparations can be administered orally or parenterally (e.g., intravenously, subcutaneously, intraperitoneally, or topically). If certain drugs are unstable under gastric conditions, they can be prepared into enteric-coated tablets.

[0034] Compared with the prior art, the present invention has the following beneficial effects:

[0035] The present invention discloses a binuclear ruthenium complex, which has a photocatalytic therapeutic effect against Staphylococcus aureus (S. aureus) and has a proliferation inhibition ability (MIC) against Staphylococcus aureus (S. aureus) under light conditions. 90 6.25μM), and can produce superoxide anions and singlet oxygen under light conditions, and has photocatalytic oxidation ability for NADH / NADPH in bacteria, which is of great significance for the study of binuclear metal ruthenium complex antibacterial drugs, and provides a new idea for the clinical development of binuclear metal ruthenium complex antibacterial photocatalytic drugs or antibacterial metal photosensitizers. BRIEF DESCRIPTION OF THE DRAWINGS

[0036] Figure 1 is the UV absorption spectrum of binuclear ruthenium complex;

[0037] Figure 2 The fluorescence excitation and emission spectra of binuclear ruthenium complexes are shown below;

[0038] Figure 3 The ability of binuclear ruthenium complexes to photocatalytically generate superoxide anions;

[0039] Figure 4 The ability of binuclear ruthenium complexes to photocatalytically generate singlet oxygen;

[0040] Figure 5 The ability of the binuclear ruthenium complex to photocatalytically oxidize NADH;

[0041] Figure 6 The ability of the binuclear ruthenium complex to photocatalytically oxidize NADPH;

[0042] Figure 7 It is a binuclear ruthenium complex that combats the dark toxicity and phototoxicity of Staphylococcus aureus (S. aureus). DETAILED DESCRIPTION

[0043] The following is a further description of specific embodiments of the present invention. It should be noted that the description of these embodiments is intended to facilitate understanding of the present invention and does not constitute a limitation of the present invention. In addition, the technical features involved in the various embodiments of the present invention described below may be combined with each other as long as they do not conflict with each other.

[0044] The experimental methods in the following examples are conventional methods unless otherwise specified, and the experimental materials used in the following examples are commercially available unless otherwise specified.

[0045] Example 1 A binuclear ruthenium complex and its preparation

[0046] The structural formula of the binuclear ruthenium complex is shown below:

[0047]

[0048] The synthesis of the binuclear ruthenium complex comprises the following steps:

[0049] (1) Ru(tpy)Cl3 is generated by the reaction of 2,2':6',2"-terpyridine with ruthenium(III) chloride hydrate.

[0050] 2,2':6',2"-terpyridine (467 mg, 2 mmol) and ruthenium(III) chloride hydrate (498 mg, 2.4 mmol) were dissolved in 15 mL of anhydrous ethanol solution, refluxed at 85 ° C for 3 h, and then cooled to room temperature. The reaction solution was filtered, and the filter cake was washed with anhydrous ethanol and petroleum ether in sequence and dried in vacuo to obtain a brown solid powder Ru(tpy)Cl3 (790 mg, 90%).

[0051] The chemical reaction equation above is as follows:

[0052]

[0053] (2) Ru(tpy)Cl3 reacts with 4'-bromo-2,2':6',2"-terpyridine to form [Ru(tpy)(tpy-Br)](PF6)2

[0054] Ru(tpy)Cl3 (441 mg, 1 mmol) and 4'-bromo-2,2':6',2"-terpyridine (318 mg, 1.02 mmol) were dissolved in 30 mL of anhydrous ethanol solution, refluxed at 85°C for 3 h, and then cooled to room temperature. 30 mL of saturated NH4PF6 aqueous solution was added and stirred at room temperature for 30 min. The reaction solution was filtered and the filter cake was washed with anhydrous ethanol, dried in vacuo, and purified by alumina chromatography to obtain the ruthenium complex [Ru(tpy)(tpy-Br)](PF6)2 as an orange powder (187 mg, 20%). The H NMR spectrum of the product is: 1 H NMR (600MHz, DMSO-d6) δ9.34(s,2H),8.98(d,J=8.2Hz,2H),8.81(d,J=8.2Hz,2H),8.72(d,J=8.1Hz,2H),8.47(t,J=8.2Hz ,1H),7.99(m,J=7.7,5.7,1.5Hz,4H),7.50(d,J=5.5Hz,2H),7.41(m,J=4.1Hz,2H),7.25(m,J=17.2,7.3,5.6,1.3Hz,4H).

[0055] The chemical reaction equation above is as follows:

[0056]

[0057] (3) [Ru(tpy)(tpy-Br)](PF6)2 reacts with 5,6-difluoro-4,7-bis(5-(trimethylstannyl)thiophen-2-yl)benzo[c][1,2,5]thiadiazole (CAS No.: 1421762-30-2) to form a new binuclear ruthenium complex

[0058] [Ru(tpy)(tpy-Br)](PF6)2 (187 mg, 0.4 mmol), 5,6-difluoro-4,7-bis(5-(trimethyltinyl)thiophen-2-yl)benzo[c][1,2,5]thiadiazole (66 mg, 0.2 mmol), and tetrakis(triphenylphosphine)palladium (12 mg, 0.02 mmol) were dissolved in 20 mL of toluene / N,N-dimethylformamide (V / V=3:1) and stirred at 115°C for 20 h under argon protection. After the reaction, the mixture was cooled to room temperature and 100 mL of saturated brine was added. The precipitate was collected by filtration, washed with water and then toluene, and dried under vacuum to obtain 182 mg (89%) of a dark red solid, which was the binuclear ruthenium complex of the present invention. The mass spectrum of the product was: ESI-MS [CH3OH, m / z]: 367 [M-4PF6 - ] 4+ ; The H NMR spectrum of the product is: 1H NMR (600MHz, DMSO-d6) δ9.50(s,4H),9.20(d,J=8.2Hz,4H),9.13(d,J=8.2Hz,4H),8.87(d,J=8.1Hz,4H),8.71(q,J=4.0Hz,4H), 8.57(t,J=8.2Hz,2H),8.10(t,J=7.4Hz,4H),8.08–8.03(m,4H),7.64(d,J=5.2Hz,4H),7.48(d,J=5.1Hz,4H),7.35–7.27(m,8H).

[0059] The chemical reaction equation above is as follows:

[0060]

[0061] Experimental Example 1 Performance Test of Binuclear Ruthenium Complex

[0062] 1. Absorbance and fluorescence spectra of binuclear ruthenium complexes in different solvents

[0063] (1) Absorbance of binuclear ruthenium complexes in different solvents

[0064] The binuclear ruthenium complex of Example 1 was prepared into a 10 μM sample solution using phosphate buffered saline (PBS), dichloromethane (DCM), and methanol (MeOH) as solvents, and then the UV absorption spectrum of the binuclear ruthenium complex was recorded using a double-beam UV-visible spectrophotometer. Figure 1 The absorbance of the compound in different solvents is shown, indicating that the absorbance is best in PBS.

[0065] (2) Fluorescence excitation and emission spectra of binuclear ruthenium complexes

[0066] The binuclear ruthenium complex of Example 1 was prepared into a 10 μM sample solution using acetonitrile as solvent, and the fluorescence emission spectrum of the ruthenium complex was recorded using a fluorescence spectrophotometer with 410 nm as the EX fixed wavelength. Similarly, the fluorescence excitation spectrum of the ruthenium complex was recorded with 580 nm as the EM fixed wavelength, as shown in FIG. Figure 2 The excitation spectrum and emission spectrum of the compound in acetonitrile are shown, indicating that the optimal excitation wavelength in acetonitrile is 410 nm and the optimal emission wavelength is 580 nm.

[0067] 2. Determination of the ability of binuclear ruthenium complexes to generate superoxide anions

[0068] To test the ability of the binuclear ruthenium complex synthesized in Example 1 to photocatalytically generate superoxide anions, dihydrorhodamine 123 (DHR 123) was used to determine the superoxide anion-generating ability of the novel binuclear ruthenium complex. When superoxide anions are generated in a solution, DHR 123 immediately captures the superoxide anions and is oxidized to form the fluorescent derivative rhodamine 123, which emits bright green fluorescence (Ex / Em = 500 / 536 nm). An increase in fluorescence intensity indicates the generation of superoxide anions in the solution. The superoxide anion-generating ability of the mixed solution of the test sample and DHR 123 is monitored by a fluorescence spectrophotometer by changes in the fluorescence spectrum of the solution under different illumination times.

[0069] An aqueous solution containing a binuclear ruthenium complex (5 μM) and a DHR 123 reagent (5 μM) was placed in a cuvette to measure its ability to generate superoxide anions under light conditions. Figure 3 As shown, the binuclear ruthenium complex has the ability to generate superoxide anions after light irradiation.

[0070] 3. Determination of the ability of binuclear ruthenium complexes to generate singlet oxygen

[0071] To test the ability of the binuclear ruthenium complex synthesized in Example 1 to photocatalytically generate singlet oxygen, the singlet oxygen probe 9,10-anthryl-bis(methylene)dimalonic acid (ABDA) was used to measure the ability of the new binuclear ruthenium complex to generate singlet oxygen. When singlet oxygen is generated in solution, ABDA immediately captures the singlet oxygen in the solution and reacts to form an endogenous oxidation product, causing the characteristic absorption peak of ABDA to decrease. The rate of decrease of the ABDA absorption peak is the singlet oxygen generation rate. The singlet oxygen generation ability is reflected by monitoring the changes in the UV-visible absorption spectrum of the test sample and the ABDA mixed solution under different illumination times using a UV-visible spectrophotometer.

[0072] Two aqueous solutions containing the same binuclear ruthenium complex (5 μM) and ABDA reagent (200 μM) were placed in a cuvette and their singlet oxygen generation capacity was measured under light and dark conditions. Figure 4 As shown, the binuclear ruthenium complex has the ability to generate singlet oxygen after light irradiation.

[0073] 4. Determination of the photocatalytic oxidation ability of binuclear ruthenium complexes for NADH / NADPH

[0074] Under light irradiation, the metal complex can oxidize reduced coenzyme I (NADH) and reduced coenzyme II (NADPH) into their oxidized forms NADPH and NADPH. + and NADP +Therefore, the ruthenium complex (5 μM) and NADH or NADPH (A 339nm =1.0) in a cuvette, and its ability to oxidize NADH / NADPH under light and dark conditions can be measured respectively. Figure 5 、 6 As shown in the figure, the ruthenium complex has obvious photocatalytic oxidation ability for NADH and NADPH.

[0075] 5. Dark toxicity and phototoxicity of binuclear ruthenium complexes against Staphylococcus aureus

[0076] The photodynamic antibacterial activity of a binuclear ruthenium complex was investigated using Staphylococcus aureus, a typical Gram-positive bacterium. S. aureus was inoculated into fresh LB medium and shaken at 150 rpm at 37°C until the exponential phase. The bacterial concentration was then determined by measuring the optical density at 600 nm. The specific experimental method is as follows:

[0077] The overnight culture of Staphylococcus aureus was diluted to 2 × 10 6 CFU / mL, and then a series of drug-containing bacterial solutions with gradient concentrations were prepared using the half-dilution method. That is, binuclear ruthenium (50 μM) was added to the diluted bacterial solution for gradient dilution, and 7 concentration gradients (0.78, 1.56, 3.13, 6.25, 12.5, 25, 50 μM) were prepared. The prepared bacterial suspension (100 μL) was added to a 96-well plate in sequence, and 100 μL of sterile and drug-free LB culture medium was added to the negative control group, and drug-free bacterial solution was added to the positive control group. The dark group was placed in a 37°C static incubator for 18 hours, and the absorbance at OD=600nm was read. After the light group was statically incubated for 4 hours, it was irradiated with a white light source for 0, 5, 20, and 40 minutes (30 mW / cm 2 ) and then returned to the incubator for 14 hours. Observe the negative control group for clarity; clarity indicates reliable data. Measure the absorbance at 600 nm using a microplate reader. The phototoxicity of the binuclear ruthenium complex is determined according to the following formula: the drug concentration at which bacterial survival is <10% is the MIC.

[0078] Survival rate (%) = (C experimental group - C negative control group) / (C positive control group - C negative control group) × 100%.

[0079] like Figure 7 As shown in the figure, different concentrations of binuclear ruthenium complexes have different killing effects on Staphylococcus aureus under dark and light treatment conditions. The binuclear ruthenium complex in the experiment has low toxicity to Staphylococcus aureus in the absence of light, but has a strong growth inhibition ability against Staphylococcus aureus under light conditions (light MIC 90=6.25 μM).

[0080] In summary, the binuclear ruthenium complex of the present invention has good absorbance in PBS solvent, the optimal excitation wavelength in acetonitrile is 410 nm, and the optimal emission wavelength is 580 nm. At the same time, the binuclear ruthenium complex has the ability to generate superoxide anions and singlet oxygen after illumination, and has obvious photocatalytic oxidation ability for NADH and NADPH; and has a strong growth inhibitory ability against Staphylococcus aureus under illumination conditions. It can be seen that the binuclear ruthenium complex of the present invention is a new type of binuclear ruthenium photocatalyst, and has great potential for development into a high-efficiency and low-toxic antibacterial photocatalytic drug or antibacterial photosensitizer.

[0081] The embodiments of the present invention are described in detail above, but the present invention is not limited to the described embodiments. It is apparent to those skilled in the art that various changes, modifications, substitutions, and variations of these embodiments may be made without departing from the principles and spirit of the present invention, and the changes still fall within the scope of protection of the present invention.

Claims

1. A binuclear ruthenium complex, characterized in that The structure of the binuclear ruthenium complex is shown below:

2. The method for preparing the binuclear ruthenium complex according to claim 1, characterized in that: The following steps are involved: S1, dissolving 2,2':6',2"-terpyridine and ruthenium (III) chloride hydrate in an organic solvent, heating and refluxing to generate a precursor compound Ru(tpy)Cl3; S2, first dissolving the precursor compounds Ru(tpy)Cl3 and 4'-bromo-2,2':6',2"-terpyridine from step S1 in an organic solvent, heating and refluxing the mixture, and then performing ion exchange with ammonium hexafluorophosphate to generate a ruthenium complex [Ru(tpy)(tpy-Br)](PF6)2; S3. Dissolve the ruthenium complex [Ru(tpy)(tpy-Br)](PF6)2, 5,6-difluoro-4,7-bis(5-(trimethyltin-2-yl)thiophene)benzo[c][1,2,5]thiadiazole and tetrakis(triphenylphosphine)palladium prepared in step S2 in an organic solvent, and react with stirring under the protection of an inert gas to obtain a binuclear ruthenium complex.

3. The method for preparing a binuclear ruthenium complex according to claim 2, wherein: In step S1, the heating reflux reaction is a reflux reaction at 75-95° C. for 2-5 hours; in step S2, the heating reflux reaction is a reflux reaction at 75-95° C. for 2-4 hours.

4. The method for preparing a binuclear ruthenium complex according to claim 2, wherein: In step S3, the stirring reaction is carried out at 100-135° C. for 18-24 hours.

5. The method for preparing a binuclear ruthenium complex according to claim 2, wherein: In step S1, the molar ratio of the 2,2':6',2"-terpyridine to ruthenium (III) chloride hydrate is 1:1.

2.

6. The method for preparing a binuclear ruthenium complex according to claim 2, wherein: In step S2, the molar ratio of the precursor Ru(tpy)Cl3 to 4'-bromo-2,2':6',2"-terpyridine is 1:1.

02.

7. The method for preparing a binuclear ruthenium complex according to claim 2, wherein: In step S3, the molar ratio of 5,6-difluoro-4,7-bis(5-(trimethyltinyl)thiophen-2-yl)benzo[c][1,2,5]thiadiazole, [Ru(tpy)(tpy-Br)](PF6)2, and tetrakis(triphenylphosphine)palladium is 1:2:0.

1.

8. Use of the binuclear ruthenium complex according to claim 1 in the preparation of antibacterial photocatalytic drugs, characterized in that: The antibacterial photocatalytic drug is a photocatalytic drug against Staphylococcus aureus.

9. An antibacterial photocatalytic drug or antibacterial metal photosensitizer, characterized in that: The binuclear ruthenium complex according to claim 1 is used as the main active ingredient.

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