Zinc sulfide-graphene oxide composite material with near-infrared light catalytic effect, preparation method and application of zinc sulfide-graphene oxide composite material and antibacterial agent

Abstract

The invention relates to the technical field of antibacterial materials, and provides a zinc sulfide-graphene oxide composite material with a near-infrared light catalytic effect, a preparation method and application of the zinc sulfide-graphene oxide composite material and an antibacterial agent. The preparation method comprises the following steps: mixing a thiourea solution, a graphene oxide nanosheet dispersion liquid and a soluble zinc salt solution for reaction to obtain the zinc sulfide-graphene oxide composite material with the near-infrared light catalytic effect. The zinc sulfide-graphene oxide composite material prepared by the invention has a good near-infrared light catalytic effect, can realize effective photo-thermal and photodynamic conversion, has a good antibacterial effect on gram-positive bacteria and gram-negative bacteria, can be used as an effective and non-invasive strategy to resist pathogens, and has good application prospects. Particularly, the compound has a good application prospect in the aspect of resisting drug-resistant pathogens.

Description

Technical Field

[0001] The present invention relates to the technical field of antibacterial materials, and in particular to a zinc sulfide-graphene oxide composite material with near-infrared photocatalytic effect, a preparation method and application thereof, and an antibacterial agent. Background Art

[0002] Bacterial infectious diseases are infectious inflammations of body tissues caused by bacteria. Prolonged inflammation can lead to dissolution and necrosis of normal tissue areas. The oral cavity is a contaminated environment, and many bacterial infectious diseases are common, such as periodontal abscess, alveolar abscess, dry socket, pericoronitis, gingivitis, etc. For common oral infectious diseases, the current mainstream view in the medical community is still to apply local antibacterial measures or drugs. In recent years, photothermal / photodynamic therapy (PTT / PDT) antibacterial has received increasing attention and is becoming an effective, non-invasive strategy to combat pathogens. PTT / PDT synergistic response therapy uses the characteristics of photosensitive materials with excellent absorption and conversion efficiency of light energy to convert light energy into heat energy. At the same time, light-responsive materials can produce active factors including hydroxyl free radicals under photocatalysis, causing an imbalance in the antioxidant system in bacteria, leading to DNA bond breakage, protein denaturation, and increased cell membrane permeability, which in turn causes a large amount of protein leakage in bacteria, causing bacteria to rupture and die, achieving a highly effective antibacterial effect. Therefore, the research and development of PTT / PDT synergistically responsive photosensitive materials has become a research hotspot and difficulty in the antibacterial field, and is of great significance to the clinical promotion and application of PTT / PDT synergistically responsive therapy in infectious diseases.

[0003] At present, the photosensitive materials of PTT / PDT synergistic response are usually obtained by compounding indocyanine green with photodynamic antibacterial ability and noble metal nanoparticles with photothermal antibacterial ability. However, the preparation method of indocyanine green is complicated and the cost of noble metal nanoparticles is high, which limits its application in PTT / PDT synergistic response therapy. At present, it is urgent to provide a photosensitive material with a simple preparation method, low cost and good photodynamic / photothermal conversion effect. Summary of the invention

[0004] In view of this, the present invention provides a zinc sulfide-graphene oxide composite material with near-infrared photocatalytic effect, a preparation method and application thereof, and an antibacterial agent. The preparation method of the zinc sulfide-graphene oxide composite material with near-infrared photocatalytic effect provided by the present invention is simple and low in cost, and has good photodynamic and photothermal conversion effects under near-infrared light irradiation, and has significant antibacterial effect.

[0005] In order to achieve the above-mentioned object of the invention, the present invention provides the following technical solutions:

[0006] A method for preparing a zinc sulfide-graphene oxide composite material having a near-infrared photocatalytic effect comprises the following steps:

[0007] The thiourea solution, the graphene oxide nanosheet dispersion and the soluble zinc salt solution are mixed and reacted to obtain the zinc sulfide-graphene oxide composite material with near-infrared photocatalytic effect.

[0008] Preferably, the concentration of thiourea in the thiourea solution is 10 to 20 mg / mL; and the pH value of the thiourea solution is 7.35 to 7.45.

[0009] Preferably, the preparation method of the thiourea solution comprises: dissolving thiourea in water, and then adjusting the pH value to 7.35-7.45 with aqueous ammonia to obtain the thiourea solution.

[0010] Preferably, the concentration of the graphene oxide nanosheet dispersion is 1.8-7.2 mg / mL; the mass ratio of the graphene oxide nanosheets in the graphene oxide nanosheet dispersion to the thiourea in the thiourea solution is 9-36:100-300.

[0011] Preferably, the concentration of the soluble zinc salt solution is 0.3-0.4 mol / L; the soluble zinc salt includes one or more of zinc sulfate, zinc nitrate and zinc chloride.

[0012] Preferably, the molar ratio of thiourea in the thiourea solution to zinc ions in the soluble zinc salt solution is 1:1 to 1.6.

[0013] Preferably, the reaction time is 20 to 30 minutes.

[0014] The present invention also provides a zinc sulfide-graphene oxide composite material with near-infrared photocatalytic effect prepared by the preparation method described in the above scheme, comprising graphene oxide and zinc sulfide modified on the surface of the graphene oxide.

[0015] The present invention also provides the use of the zinc sulfide-graphene oxide composite material with near-infrared photocatalytic effect described in the above scheme in the preparation of an antibacterial agent.

[0016] The present invention also provides an antibacterial agent, comprising a photosensitive material and a drug-carrying matrix; the photosensitive material is the zinc sulfide-graphene oxide composite material with near-infrared photocatalytic effect described in the above scheme.

[0017] The invention provides a method for preparing a zinc sulfide-graphene oxide composite material with near-infrared photocatalytic effect, comprising the following steps: mixing a thiourea solution, a graphene oxide nanosheet dispersion and a soluble zinc salt solution for reaction to obtain the zinc sulfide-graphene oxide composite material with near-infrared photocatalytic effect. The present invention adopts thiourea as a sulfur source, adopts a soluble zinc salt to provide zinc ions, and generates zinc sulfide in situ on the surface of graphene oxide, thereby realizing uniform modification of the surface of graphene oxide with zinc sulfide; the zinc sulfide-graphene oxide composite material prepared by the present invention has good near-infrared photocatalytic effect, can realize effective photothermal and photodynamic conversion, and can generate hydroxyl radicals based on the photocatalytic effect under near-infrared illumination conditions, causing an imbalance of the antioxidant system in bacteria, increasing the permeability of the cell membrane, and further causing a large amount of protein in the bacteria to leak out, causing the bacteria to rupture and die, and having a good antibacterial effect on Staphylococcus aureus (Gram-positive bacteria) and Escherichia coli (Gram-negative bacteria); at the same time, because graphene oxide has excellent optical absorption performance and thermal conductivity, when light energy is irradiated to the surface of graphene oxide, photons are absorbed and converted into heat energy, causing the graphene oxide to heat up, and the heat is radiated to the surrounding system, causing the system to heat up. In summary, the zinc sulfide-graphene oxide composite material prepared by the present invention has good photodynamic / photothermal antibacterial effect, and can be used as an effective and non-invasive strategy to combat pathogens, especially in the combat of drug-resistant pathogens, and has good application prospects.

[0018] In addition, the preparation method provided by the present invention has a wide range of raw material sources, low cost, and simple operation, which is conducive to large-scale preparation. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 The results of the methylene blue degradation experiment in Example 4 are shown in FIG. 1 , wherein the left side shows the degree of fading of methylene blue and the right side shows the concentration of methylene blue;

[0020] Figure 2 The results of the methylene blue degradation experiment under different ZnS / GO concentrations in Example 4, where the left side shows the fading degree of methylene blue and the right side shows the concentration of methylene blue;

[0021] Figure 3 The antibacterial performance test results under non-near infrared light in Example 5;

[0022] Figure 4 The antibacterial performance test results under near-infrared illumination in Example 5;

[0023] Figure 5 The results of bacterial protein leakage detection in Example 6, wherein the left side is the protein concentration graph measured by Coomassie Brilliant Blue method, and the right side is the protein concentration quantitative analysis result;

[0024] Figure 6 The test results of the material heating curve in Example 7 are as follows;

[0025] Figure 7 The thermal stability test results of the materials in Example 7 are shown in FIG. DETAILED DESCRIPTION

[0026] The present invention provides a method for preparing a zinc sulfide-graphene oxide composite material having a near-infrared photocatalytic effect, comprising the following steps:

[0027] The thiourea solution, the graphene oxide nanosheet dispersion and the soluble zinc salt solution are mixed and reacted to obtain the zinc sulfide-graphene oxide composite material with near-infrared photocatalytic effect.

[0028] In the present invention, the concentration of thiourea in the thiourea solution is preferably 10-20 mg / mL, more preferably 13-15 mg / mL; the pH value of the thiourea solution is preferably 7.35-7.45, more preferably 7.4; the preparation method of the thiourea solution comprises: dissolving thiourea in water, and then adjusting the pH value to 7.35-7.45 with ammonia water to obtain the thiourea solution; the concentration of the ammonia water is preferably 7wt%. The present invention controls the pH value of the thiourea solution within the above range, which can promote the reaction between thiourea and zinc ions to obtain zinc sulfide with uniform particle size.

[0029] In the present invention, the concentration of the graphene oxide nanosheet dispersion is preferably 1.8-7.2 mg / mL; the method for preparing the graphene oxide nanosheet dispersion preferably comprises: adding the graphene oxide nanosheets into deionized water, and then ultrasonicating until the graphene oxide nanosheets are uniformly dispersed.

[0030] In the present invention, the mass ratio of the graphene oxide nanosheets in the graphene oxide nanosheet dispersion to the thiourea in the thiourea solution is preferably 9-36:100-300, specifically 9:150, 18:150 or 36:150.

[0031] In the present invention, the concentration of the soluble zinc salt solution is preferably 0.3-0.4 mol / L, more preferably 0.3-0.35 mol / L; the soluble zinc salt preferably includes one or more of zinc sulfate, zinc nitrate and zinc chloride, more preferably zinc sulfate; the molar ratio of thiourea in the thiourea solution to zinc ions in the soluble zinc salt solution is preferably 1:1-1.6.

[0032] In a specific embodiment of the present invention, it is preferred to first add the graphene oxide nanosheet dispersion into the thiourea solution, stir for 15 to 20 minutes to obtain a mixed solution, and then dropwise add the soluble zinc salt solution into the mixed solution to react.

[0033] In the present invention, the reaction temperature is preferably room temperature, the reaction time is preferably 20 to 30 minutes, and the reaction time is counted from the completion of the dropwise addition of the soluble zinc salt; the reaction is preferably carried out under stirring conditions.

[0034] After the reaction is completed, the present invention preferably centrifuges the obtained reaction solution, collects the solid product, and then washes and dries the solid product to obtain the zinc sulfide-graphene oxide composite material with near-infrared photocatalytic effect; the centrifugal speed is preferably 12000 rpm, and the centrifugal time is preferably 10 min; the washing is preferably performed alternately with deionized water and ethanol until the supernatant is colorless; the drying is preferably vacuum drying, and the vacuum drying temperature is preferably 60°C.

[0035] The present invention also provides a zinc sulfide-graphene oxide composite material with near-infrared photocatalytic effect prepared by the preparation method described in the above scheme, comprising graphene oxide and zinc sulfide modified on the surface of the graphene oxide.

[0036] The present invention also provides the use of the zinc sulfide-graphene oxide composite material with near-infrared photocatalytic effect described in the above scheme in the preparation of an antibacterial agent; the antibacterial agent is specifically an antibacterial agent with photothermal and photodynamic synergistic response, and the zinc sulfide-graphene oxide composite material is specifically used as a photosensitive material in the antibacterial agent; the zinc sulfide-graphene oxide composite material provided by the present invention can perform effective photothermal and photodynamic conversion under near-infrared light irradiation, showing significant antibacterial therapeutic effect, and showing antibacterial activity against both Gram-positive bacteria and Gram-negative bacteria.

[0037] The present invention also provides an antibacterial agent, which preferably includes a photosensitive material and a drug-carrying matrix, wherein the photosensitive material is the zinc sulfide-graphene oxide composite material with near-infrared photocatalytic effect as described in the above scheme; the present invention has no special requirements for the drug-carrying matrix, and any drug-carrying matrix familiar to those skilled in the art can be used, such as a gel; in a specific embodiment of the present invention, the antibacterial agent can be applied locally and then subjected to antibacterial treatment under near-infrared light.

[0038] The following will be combined with the embodiments of the present invention to clearly and completely describe the technical solutions of the present invention. 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 creative work are within the scope of protection of the present invention.

[0039] Example 1

[0040] Dissolve thiourea in deionized water, then add 11 drops of 7wt% ammonia water to obtain a thiourea solution with a pH value of 7.4 and a concentration of 15 mg / mL; add 9 mg of graphene oxide nanosheets to 5 mL of deionized water, and ultrasonicate until uniformly dispersed to obtain a graphene oxide nanosheet dispersion; add the obtained graphene oxide nanosheet dispersion to 10 mL of thiourea solution, magnetically stir for 15 minutes, and obtain a mixed solution.

[0041] A zinc sulfate solution with a concentration of 0.3 mol / L was prepared, and 10 mL of the zinc sulfate solution was slowly added to the above mixed solution with a pipette, and magnetic stirring was performed at room temperature for 30 min. The resulting reaction solution was then centrifuged (12000 rpm, 10 min) to collect the solid product; the solid product was alternately washed with deionized water and ethanol until the supernatant was colorless, and then vacuum dried at 60°C to obtain a zinc sulfide-graphene oxide composite material (denoted as ZnS / GO) with near-infrared photocatalytic effect.

[0042] Example 2

[0043] The other conditions were the same as those in Example 1, except that the amount of graphene oxide nanosheets was changed to 18 mg, to obtain a zinc sulfide-graphene oxide composite material with near-infrared photocatalytic effect.

[0044] Example 3

[0045] The other conditions were the same as those in Example 1, except that the amount of graphene oxide nanosheets was changed to 36 mg, to obtain a zinc sulfide-graphene oxide composite material with near-infrared photocatalytic effect.

[0046] The ZnS / GO prepared in Example 1 was used to carry out the experiments in Examples 4 to 6.

[0047] Example 4 Hydroxyl Radical Detection

[0048] (1) Based on the principle that methylene blue changes color after being oxidized by hydroxyl radicals, the generation of active hydroxyl radicals in ZnS / GO under near-infrared light was detected. First, ZnS, GO and ZnS / GO solutions with a concentration of 200 μg / mL were prepared respectively. The solvents were all sterile deionized water. No material was added to the Con group. 1 mL of solution was taken from each group and added to a 1.5 mL centrifuge tube. The near-infrared light (NIR) was irradiated at 1.5 W / cm 2 Prepare a 96-well plate, add 200 μL of 0.01% methylene blue solution to each well, take 10 μL of the supernatant after irradiation from each well and add it to the methylene blue solution, and after reacting for 5 minutes, measure the fading degree of methylene blue at a wavelength of 660 nm and calculate the concentration of methylene blue. Set up three parallel experiments for each group, and take the average value of the methylene blue concentration.

[0049] Test results such as Figure 1 As shown, Figure 1 The left side shows the degree of fading of methylene blue, and the right side shows the concentration of methylene blue. Figure 1 It can be seen from the test results that after 5 minutes of NIR irradiation, the methylene blue content of the ZnS / GO group was significantly reduced, while the degradation amounts of methylene blue in the ZnS group and the GO group were both small, indicating that ZnS / GO has a photocatalytic degradation effect and can produce hydroxyl radicals under NIR irradiation.

[0050] (2) The concentration of ZnS / GO was controlled to 100 μg / mL, 200 μg / mL and 400 μg / mL, respectively, and the methylene blue degradation test was carried out in the same manner as in (1). The results are shown in Figure 2. Figure 2 As shown, Figure 2 The left side shows the degree of fading of methylene blue, and the right side shows the concentration of methylene blue. Figure 2 It can be seen that the degradation amount of methylene blue is concentration-dependent. The higher the concentration of ZnS / GO, the greater the degradation amount of methylene blue.

[0051] Example 5 Antibacterial Performance Detection

[0052] Escherichia coli (E. coli) and Staphylococcus aureus (S. aureus) were cultured overnight until the plateau phase, and the bacterial concentration was measured by an ELISA reader at 600 nm. The bacterial solution was diluted to an appropriate concentration with PBS, and the material suspension (ZnS suspension, GO suspension or ZnS / GO suspension) was added. The bacterial concentration in the resulting mixed solution was 1×10 6 CFU / mL, the material concentration was 100-400μg / mL (the material concentration of the ZnS group was 200μg / mL, the material concentration of the GO group was 200μg / mL, the concentrations of the ZnS / GO group were 100μg / mL, 200μg / mL, and 400μg / mL, respectively, and no material was added to the Con group); the mixed solution (200μL) was transferred to a 1.5mL EP tube and irradiated with NIR for 5min, with a wavelength of 808nm and an intensity of 1.5W / cm 2 , and the liquid temperature was detected in real time and controlled to ≤55°C; the irradiated bacterial liquid mixture was plated and the colony formation was observed after overnight culture at 37°C. At the same time, the experiment was carried out without NIR irradiation for comparison.

[0053] Test results such as Figure 3 and Figure 4 As shown, Figure 3 The antibacterial performance test results under non-near infrared light. Figure 4 The antibacterial performance test results under near-infrared light conditions. Figure 3 and Figure 4It can be seen that under non-near-infrared light conditions, ZnS, GO and ZnS / GO have no antibacterial properties, while under near-infrared light conditions, ZnS and GO still have no significant antibacterial properties, while the colony of the ZnS / GO group is significantly reduced, indicating that ZnS / GO has good antibacterial properties against Escherichia coli and Staphylococcus aureus under near-infrared stimulation.

[0054] Example 6 Bacterial protein leakage detection

[0055] Escherichia coli (E. coli) and Staphylococcus aureus (S. aureus) were cultured overnight until the plateau phase, and the bacterial concentration was measured at 600 nm using an ELISA reader. The bacterial solution was diluted to an appropriate concentration using PBS, and the material suspension (ZnS suspension, GO suspension or ZnS / GO suspension) was added. The bacterial concentration in the resulting mixed solution was 1×10 6 CFU / mL, the material concentration was 200μg / mL (no material in the Con group); the mixed solution (200μL) was transferred to a 1.5mL EP tube and irradiated with NIR for 5min, with a wavelength of 808nm and an intensity of 1.5W / cm 2 , and detect the liquid temperature in real time, and control the liquid temperature to ≤55°C; centrifuge the irradiated bacteria and material mixture at a centrifugal force of 10000g for 5 minutes, take 10μL of the supernatant after centrifugation and add it to 200μL of Coomassie Brilliant Blue solution, and determine the protein concentration leaked by bacteria according to the Bradford test method. Set up three parallel experiments for each group, and take the average protein concentration.

[0056] Test results such as Figure 5 As shown, Figure 5 The left side shows the protein concentration measured by Coomassie Brilliant Blue method, and the right side shows the quantitative analysis result of protein concentration. Figure 5 It can be seen that after NIR stimulation, the bacteria in the ZnS / GO group ruptured and died, and the protein leakage increased significantly, while neither the ZnS group nor the GO group had obvious antibacterial effect.

[0057] Example 7 Photothermal performance test

[0058] (1) Heating curve test: The vacuum-dried ZnS, GO, and ZnS / GO powders were prepared into a solution with a concentration of 200 μg / mL. The solvent was deionized water. No material was added to the Con group. 200 μL of the above solution was added to a 1.5 mL EP tube, and then vortexed and near-infrared light was used for excitation (808 nm, 1.5 W / cm 2 ), the temperature detector detects temperature changes in real time and records the sample temperature once a minute for a total of 10 minutes.

[0059] Test results such as Figure 6As shown, according to the temperature rise curve, it can be seen that the Con control group and the ZnS group did not show obvious temperature rise, the GO group heated up by about 26°C, and the ZnS / GO group heated up by about 29°C, proving that ZnS / GO has good photothermal conversion performance like GO.

[0060] (2) Thermal stability test: The vacuum-dried ZnS, GO, and ZnS / GO powders were prepared into solutions with a concentration of 200 μg / mL. The solvent was deionized water. No material was added to the Con group. 200 μL of the above solutions were added to 1.5 mL EP tubes, and then vortexed and near-infrared light was used for excitation (808 nm, 1.5 W / cm 2 ), the temperature detector detects the temperature change in real time for a total of 10 minutes, and the temperature of the sample is recorded once a minute; then the light source is turned off for a total of 10 minutes, and the temperature of the sample is recorded once a minute. 20 minutes is regarded as a cycle, and 5 cycles are performed.

[0061] Test results such as Figure 7 As shown in the figure, the photothermal cycle test results show that ZnS / GO has obvious temperature rise within 5 photothermal cycles, and the temperature drops rapidly after removing the near-infrared light source. The morphology of the 5 cycle curves is consistent, while the heating performance of GO gradually decreases in 4 to 5 cycles, indicating that the ZnS / GO material has better photothermal stability.

[0062] The ZnS / GO prepared in Examples 2 to 3 was tested according to the methods in Examples 4 to 7, and the results were similar to those of the ZnS / GO prepared in Example 1, indicating that the ZnS / GO prepared in Examples 2 to 3 had photothermal / photodynamic conversion effects and had good antibacterial properties under NIR irradiation.

[0063] The above is only a preferred embodiment of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the principle of the present invention. These improvements and modifications should also be regarded as the scope of protection of the present invention.

Claims

1. A method for preparing a zinc sulfide-graphene oxide composite material having near-infrared photocatalytic effect, characterized in that: The following steps are involved: The thiourea solution, the graphene oxide nanosheet dispersion and the soluble zinc salt solution are mixed and reacted to obtain the zinc sulfide-graphene oxide composite material with near-infrared photocatalytic effect.

2. The preparation method according to claim 1, characterized in that: The concentration of thiourea in the thiourea solution is 10-20 mg / mL; the pH value of the thiourea solution is 7.35-7.

45.

3. The preparation method according to claim 2, characterized in that: The preparation method of the thiourea solution comprises: dissolving thiourea in water, and then adjusting the pH value to 7.35-7.45 with ammonia water to obtain the thiourea solution.

4. The preparation method according to claim 1, characterized in that: The concentration of the graphene oxide nanosheet dispersion is 1.8-7.2 mg / mL; the mass ratio of the graphene oxide nanosheets in the graphene oxide nanosheet dispersion to the thiourea in the thiourea solution is 9-36:100-300.

5. The preparation method according to claim 1, characterized in that: The concentration of the soluble zinc salt solution is 0.3-0.4 mol / L; the soluble zinc salt includes one or more of zinc sulfate, zinc nitrate and zinc chloride.

6. The preparation method according to claim 1 or 5, characterized in that: The molar ratio of thiourea in the thiourea solution to zinc ions in the soluble zinc salt solution is 1:1 to 1.

6.

7. The preparation method according to claim 1, characterized in that: The reaction time is 20 to 30 minutes.

8. The zinc sulfide-graphene oxide composite material with near-infrared photocatalytic effect prepared by the preparation method according to any one of claims 1 to 7, characterized in that: The invention comprises graphene oxide and zinc sulfide modified on the surface of the graphene oxide.

9. Use of the zinc sulfide-graphene oxide composite material with near-infrared photocatalytic effect according to claim 8 in the preparation of an antibacterial agent.

10. An antibacterial agent, characterized in that It comprises a photosensitive material and a drug-carrying matrix; the photosensitive material is the zinc sulfide-graphene oxide composite material with near-infrared photocatalytic effect as described in claim 8.

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