Strontium ion-doped carbon quantum dots, synthesis method and antibacterial use thereof

Abstract

The application discloses strontium ion doped carbon quantum dots, a synthesis method thereof and antibacterial use, and directly synthesizes strontium ion doped carbon quantum dots with a hydrophobic surface through a solvothermal method in one step. The preparation process is simple, the cost is low, and large-scale production can be realized. The antibacterial coating has excellent antibacterial performance.

Description

Technical Field

[0001] This invention belongs to the field of antibacterial fabric technology, specifically relating to the preparation and application of a strontium ion-doped carbon quantum dot antibacterial fabric coating. Background Technology

[0002] Human production activities are always accompanied by the proliferation of various bacteria. While the extensive use of disinfectants and antibiotics can effectively kill bacteria, it also leaves behind numerous safety hazards. Textiles, such as underwear, socks, towels, and bed sheets, generally come into frequent contact with the human body. The wearer's body temperature, sweat, and skin flakes provide a favorable environment for microbial growth. When a large number of bacteria proliferate on human skin, they can harm the body through the skin, digestive tract, and blood, causing various skin diseases and even cancer.

[0003] Currently, traditional antibacterial agents have various limitations. For example, natural antibacterial agents such as polysaccharides and peptides have low bactericidal efficiency; compound antibacterial agents such as organic acids, phenols, quaternary ammonium salts, and imidazoles pose serious safety risks; and the delayed antibacterial effect and cost of metal ions are difficult to resolve. Therefore, developing superior antibacterial methods with good biocompatibility and low cost is key to the preparation of antibacterial fabrics.

[0004] As living standards improve, people's demands for clothing have moved beyond just aesthetics and comfort; they now place higher demands on safety. Therefore, antibacterial fabrics are becoming increasingly popular. Summary of the Invention

[0005] The purpose of this invention is to provide a method for preparing and applying a strontium ion-doped carbon quantum dot antibacterial fabric coating. Through the ingenious design of the antibacterial fabric, the fabric has a good antibacterial effect, providing a potential solution for fabric antibacterial.

[0006] To achieve the above objectives, the present invention adopts the following technical solution:

[0007] A strontium ion-doped carbon quantum dot, characterized by being prepared using the following steps:

[0008] Step 1: Weigh 0.1 mol of strontium acetate and 0.5 mol of sodium hydroxide and dissolve them in 60 mL of ethanol solution using an ultrasonic-assisted method. Stir vigorously at room temperature for 1-2 hours.

[0009] Step 2: Transfer the above mixed solution to a 100 mL polytetrafluoroethylene reactor and place it in an oven at 200°C for 24 hours.

[0010] Step 3: After the reaction is complete, the precipitate is washed with 1M hydrochloric acid solution until neutral, and then placed in a vacuum drying oven and dried at 50-60°C for 12 hours to obtain strontium ion-doped carbon quantum dot powder with a hydrophobic surface.

[0011] The carbon quantum dot particles have a particle size of 3.5nm-5nm, a hydrophobic surface, and a strontium ion doping content of 1.5-2% by mass.

[0012] A method for synthesizing strontium ion-doped carbon quantum dots, characterized by the following steps: (1) Dissolving 0.1 mol of organic strontium and 0.5 mol of sodium hydroxide in 60 mL of ethanol solvent by ultrasonic-assisted method, and stirring at room temperature for 1-2 hours; (2) Transferring the above mixed solution to a 100 mL polytetrafluoroethylene reactor and placing it in an oven at 200-240°C for 24-72 hours; (3) Washing the precipitate obtained after the reaction with 1 M hydrochloric acid solution until neutral, and placing it in a vacuum drying oven at 50-60°C for 12 hours to obtain hydrophobic strontium ion-doped carbon quantum dot powder.

[0013] A method for synthesizing strontium ion-doped carbon quantum dots, characterized in that: the organic strontium is strontium acetate, strontium acetylacetone, or strontium citrate.

[0014] A method for synthesizing strontium ion-doped carbon quantum dots, characterized in that: when the organic strontium raw material is strontium acetate, the reaction temperature is 200°C and the reaction time is 24 hours; when the organic strontium raw material is strontium acetylacetone, the reaction temperature is 220°C and the reaction time is 48 hours; when the organic strontium raw material is strontium citrate, the reaction temperature is 240°C and the reaction time is 72 hours.

[0015] An antibacterial application of strontium ion-doped carbon quantum dots is characterized by: uniformly dispersing 1.5 grams of carbon quantum dots in 10 ml of chloroform, adding 10 grams of polyurethane, stirring for 1 hour, uniformly coating the mixture onto the surface of a fabric, and drying it in a 50°C oven for 1-2 hours to obtain a fabric with an antibacterial coating of strontium ion-doped carbon quantum dots.

[0016] This invention uses organic strontium as a raw material to synthesize strontium ion-doped carbon quantum through a one-step solvothermal method under alkaline conditions and applies it to antibacterial fabric coatings.

[0017] The strontium-doped carbon quantum dot antibacterial fabric coating of this invention utilizes quantum dots that slowly release strontium ions into the bacterial environment upon contact with the surface. These strontium ions disrupt the bacterial cell membrane structure, inhibiting bacterial growth. Furthermore, the carbon quantum dots absorb light across the entire spectrum from ultraviolet-visible to near-infrared, exhibiting a powerful photothermal antibacterial effect. They also generate a large number of hydroxyl radicals, disrupting the redox balance within the bacteria and leading to bacterial death. The prepared strontium-doped carbon quantum dot antibacterial fabric coating represents a highly promising antibacterial method.

[0018] The synthesis steps of the antibacterial fabric coating of the present invention are simple and the cost is low, thus making it suitable for large-scale production. The antibacterial properties of the strontium ion-doped carbon quantum dot antibacterial fabric coating of the present invention are reflected in the following three aspects: (1) Direct contact antibacterial mechanism: Strontium ion-doped carbon quantum dots can slowly release strontium ions into the bacterial environment in contact with the surface for a long time, thereby inhibiting the growth of bacteria by destroying the structure of the bacterial cell membrane. (2) Photothermal antibacterial mechanism: Carbon quantum dots have a high photothermal conversion capability. Under the irradiation of near-infrared light, the electrons on the surface of carbon quantum dots absorb light energy and transition from the ground state to the excited state, releasing a large amount of energy in the form of heat energy, which kills bacteria by rapidly raising the temperature. (3) Carbon quantum dots can generate reactive oxygen species when exposed to light, which can disrupt the redox balance of bacteria, causing oxidative damage and thus killing bacteria.

[0019] Understandably, the strontium ion-doped carbon quantum dot antibacterial fabric coating can significantly reduce bacterial growth on fabrics, posing little harm to the human body and possessing good biocompatibility. Furthermore, the fabric coating of this invention uses inexpensive raw materials and has a simple preparation process, making it easy to mass-produce. Attached Figure Description

[0020] Figure 1 This is a transmission electron microscope image of the strontium ion-doped carbon quantum dots in Example 1.

[0021] Figure 2 The image shows the fluorescence detection pattern of the strontium ion-doped carbon quantum dots in Example 1.

[0022] Figure 3 The image shows the photothermal performance of strontium ion-doped carbon quantum dots in Example 1.

[0023] Figure 4 The curves show the degradation of methylene blue by reactive oxygen species generated under ultraviolet light in Strontium ion-doped carbon quantum dots in Example 1.

[0024] Figure 5 This is an infrared thermal image of the fabric coating prepared in Example 1.

[0025] Figure 6The diagram shows the antibacterial properties of the fabric coating prepared in Example 1. Detailed Implementation

[0026] To illustrate the structural features, technical means, objectives, and effects of the present invention in detail, the following description is provided in conjunction with the embodiments and accompanying drawings.

[0027] The strontium acetate, strontium citrate, strontium acetylacetone, sodium hydroxide, ethanol, hydrochloric acid, polyurethane, and chloroform used are all commonly used chemical raw materials in the preparation and can be ordered directly from reagent websites.

[0028] The present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments, but this should not be construed as limiting the present invention. Any modifications or substitutions made to the methods, steps, or conditions of the present invention without departing from the spirit and substance of the invention are within the scope of the present invention. Experimental methods and reagents not specifically described in the embodiments are performed according to conventional conditions in the art. Example 1

[0029] (1) Weigh 0.1 mol of strontium acetate and 0.5 mol of sodium hydroxide and dissolve them in 60 mL of ethanol solution by ultrasonic-assisted method, and stir vigorously at room temperature for 1-2 hours;

[0030] (2) Transfer the above mixed solution to a 100 mL polytetrafluoroethylene reactor and place it in an oven at 200°C for 24 hours;

[0031] (3) The precipitate obtained after the reaction is completed is washed with 1M hydrochloric acid solution until neutral, and then placed in a vacuum drying oven and dried at 50-60°C for 12 hours to obtain strontium ion-doped carbon quantum dot powder with hydrophobic surface.

[0032] (4) Disperse 1.5 g of carbon quantum dots evenly in 10 ml of chloroform, add 10 g of polyurethane, stir for 1 hour, then coat it evenly on the surface of the fabric, and dry it in a 50°C oven for 1-2 hours to obtain a fabric with an antibacterial coating of strontium ion-doped carbon quantum dots. Example 2

[0033] (1) Weigh 0.1 mol of strontium acetylacetone and 0.5 mol of sodium hydroxide and dissolve them in 60 mL of ethanol solution by ultrasonic-assisted method, stirring vigorously at room temperature for 1-2 hours;

[0034] (2) Transfer the above mixed solution to a 100 mL polytetrafluoroethylene reactor and place it in an oven at 220°C for 48 hours;

[0035] (3) The precipitate obtained after the reaction is completed is washed with 1M hydrochloric acid solution until neutral, and then placed in a vacuum drying oven and dried at 50-60°C for 12 hours to obtain strontium ion-doped carbon quantum dot powder with hydrophobic surface.

[0036] (4) Disperse 1.5 g of carbon quantum dots evenly in 10 ml of chloroform, add 10 g of polyurethane, stir for 1 hour, then coat it evenly on the surface of the fabric, and dry it in a 50°C oven for 1-2 hours to obtain a fabric with an antibacterial coating of strontium ion-doped carbon quantum dots. Example 3

[0037] (1) Weigh 0.1 mol of strontium citrate and 0.5 mol of sodium hydroxide and dissolve them in 60 mL of ethanol solution by ultrasonic-assisted method, stirring vigorously at room temperature for 1-2 hours;

[0038] (2) Transfer the above mixed solution to a 100 mL polytetrafluoroethylene reactor and place it in an oven at 240°C for 72 hours;

[0039] (3) The precipitate obtained after the reaction is completed is washed with 1M hydrochloric acid solution until neutral, and then placed in a vacuum drying oven and dried at 50-60°C for 12 hours to obtain strontium ion-doped carbon quantum dot powder with hydrophobic surface.

[0040] (4) Disperse 1.5 g of carbon quantum dots evenly in 10 ml of chloroform, add 10 g of polyurethane, stir for 1 hour, then coat it evenly on the surface of the fabric, and dry it in a 50°C oven for 1-2 hours to obtain a fabric with an antibacterial coating of strontium ion-doped carbon quantum dots.

[0041] Performance testing:

[0042] 1. Morphology determination of strontium ion-doped carbon quantum dots

[0043] The morphology of the prepared carbon quantum dots was analyzed using transmission electron microscopy, such as... Figure 1 As shown, the synthesized strontium ion-doped carbon quantum dots exhibit a near-spherical shape with a particle size of 3.5 nm to 5 nm.

[0044] 2. Determination of fluorescence properties of strontium ion-doped carbon quantum dots

[0045] Prepare carbon quantum dot ethanol mixtures of 1.0, 0.8, and 0.6 mg / mL, disperse them evenly by ultrasonication, and detect the fluorescence intensity (excitation wavelength 400 nm, slit width 5 nm / 5 nm).

[0046] pass Figure 2It can be seen that the prepared carbon quantum dot mixture exhibits fluorescence at 525 nm, and the fluorescence intensity increases continuously with the increase of carbon quantum dot concentration.

[0047] 3. Detection of the photothermal properties of strontium ion-doped carbon quantum dots

[0048] 0.5 mg and 0.25 mg of carbon quantum dots were dispersed in 0.5 mL of deionized water, respectively, and ultrasonically dispersed evenly. The dispersion was then irradiated with an 808 nm laser, and the real-time temperature changes were recorded.

[0049] pass Figure 3 It can be seen that carbon quantum dots exhibit a significant temperature increase under 808nm laser irradiation, and the heating rate and temperature increase are faster and higher with increasing carbon quantum dot concentration. This demonstrates that carbon quantum dots possess excellent photothermal properties.

[0050] 4. Performance testing of strontium ion-doped carbon quantum dots in generating reactive oxygen species.

[0051] A methylene blue solution containing 0.5 mg / mL carbon quantum dots (15 μg / mL) was prepared, irradiated with ultraviolet light, and stirred for a period of time. The change in absorbance at 644 nm was then measured.

[0052] pass Figure 4 It can be observed that the methylene blue solution begins to decompose after light exposure, and its absorbance at 644 nm decreases within 30 minutes. When strontium-doped carbon quantum dots are added to the methylene blue solution and then exposed to light, the solution decomposes rapidly, and its absorbance at 644 nm in the same time period is significantly lower than that of the methylene blue solution without carbon quantum dots. Therefore, it can be concluded that strontium-doped carbon quantum dots can generate reactive oxygen species upon light exposure, thereby oxidizing and decomposing methylene blue.

[0053] 5. Infrared thermal imaging detection of strontium ion-doped carbon quantum dot photothermal antibacterial fabric coatings

[0054] 0.5 mg of carbon quantum dots were evenly dispersed in 10 ml of chloroform, and then 3 g of polyurethane was added. After stirring for 1 hour, the mixture was evenly coated on the surface of the fabric and dried in a 50°C oven for 1-2 hours to obtain a fabric with an antibacterial coating of strontium ion-doped carbon quantum dots. The fabric was then placed under 808 nm laser irradiation and the temperature change was recorded in real time using an infrared thermal imager.

[0055] pass Figure 5 It can be seen that the prepared carbon quantum dot fabric coating is brownish-yellow and exhibits fluorescence after irradiation with a 365nm ultraviolet lamp. The temperature rises rapidly after irradiation with an 808nm laser. This indicates that the prepared carbon quantum dot fabric coating possesses excellent photothermal conversion properties, providing a good foundation for photothermal antibacterial effects.

[0056] 6. Test on the antibacterial effect of strontium ion-doped carbon quantum dot photothermal antibacterial fabric coating

[0057] 1.5 g of carbon quantum dots were uniformly dispersed in 10 mL of chloroform, and then 10 g of polyurethane was added. After stirring for 1 hour, the mixture was evenly coated onto the surface of a fabric and dried in a 50°C oven for 1-2 hours to obtain a fabric with an antibacterial coating of strontium ions-doped carbon quantum dots. The antibacterial properties of ordinary fabric and the prepared coated fabric were tested under different conditions.

[0058] pass Figure 6 It can be seen that ordinary fabrics have no inhibitory effect on Staphylococcus aureus and Escherichia coli, and even the addition of light has almost no effect. Fabrics modified with carbon quantum dots have a certain inhibitory effect on Staphylococcus aureus and Escherichia coli, mainly because carbon quantum dots can slowly release strontium ions into the bacterial environment on the surface over a long period. These strontium ions disrupt the bacterial cell membrane structure, inhibiting their growth. When carbon quantum dot-modified fabrics are exposed to light, their antibacterial ability is greatly enhanced. This is not only due to the inherent bactericidal properties of carbon quantum dots themselves, but also to the synergistic effect of photothermal activity and the generated reactive oxygen species under light conditions. The experimental results demonstrate that the strontium ion-doped carbon quantum dot antibacterial fabric coating possesses excellent antibacterial effects and has the potential for practical application.

Claims

1. A strontium ion-doped carbon quantum dot, characterized in that: It is prepared by the following steps: Step 1: Weigh 0.1 mol of strontium acetate and 0.5 mol of sodium hydroxide and dissolve them in 60 mL of ethanol solution using an ultrasonic-assisted method. Stir vigorously at room temperature for 1-2 hours. Step 2: Transfer the above mixed solution to a 100 mL polytetrafluoroethylene reactor and place it in an oven at 200°C for 24 hours. Step 3: After the reaction is complete, the precipitate is washed with 1M hydrochloric acid solution until neutral, and then placed in a vacuum drying oven and dried at 50-60°C for 12 hours to obtain strontium ion-doped carbon quantum dot powder with a hydrophobic surface.

2. The strontium ion-doped carbon quantum dot as described in claim 1, characterized in that: The carbon quantum dot particles have a particle size of 3.5nm-5nm, a hydrophobic surface, and a strontium ion doping content of 1.5-2% by mass.

3. A method for synthesizing strontium ion-doped carbon quantum dots as described in claim 1, characterized in that: Includes the following steps: (1) Dissolve 0.1 mol of organic strontium and 0.5 mol of sodium hydroxide in 60 mL of ethanol solvent by ultrasonic-assisted method and stir at room temperature for 1-2 hours; (2) Transfer the above mixed solution to 100 mL of polytetrafluoroethylene reactor and place it in an oven at 200-240°C for 24-72 hours; (3) After the reaction is completed, wash the precipitate with 1 M hydrochloric acid solution until neutral, and place it in a vacuum drying oven at 50-60°C for 12 hours to obtain strontium ion-doped carbon quantum dot powder with hydrophobic surface.

4. The method for synthesizing strontium ion-doped carbon quantum dots as described in claim 3, characterized in that: The organic strontium is strontium acetate, strontium acetylacetone, or strontium citrate.

5. The method for synthesizing strontium ion-doped carbon quantum dots as described in claim 3, characterized in that: When the organic strontium raw material is strontium acetate, the reaction temperature is 200°C and the reaction time is 24 hours; when the organic strontium raw material is strontium acetylacetone, the reaction temperature is 220°C and the reaction time is 48 hours; when the organic strontium raw material is strontium citrate, the reaction temperature is 240°C and the reaction time is 72 hours.

6. The antibacterial use of the strontium ion-doped carbon quantum dots according to claim 1, characterized in that: Disperse 1.5 g of carbon quantum dots evenly in 10 ml of chloroform, add 10 g of polyurethane, stir for 1 hour, then coat it evenly on the surface of the fabric and dry it in a 50°C oven for 1-2 hours to obtain a fabric with an antibacterial coating of strontium ion-doped carbon quantum dots.

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