A carbon dot material with both whitening and antibacterial functions and its application

Abstract

This invention discloses a carbon dot material with both whitening and antibacterial functions and its application. The carbon dot material is synthesized by a hydrothermal method using fluorescent whitening agent VBL, citric acid, copper chloride, ammonia, ethylenediamine, and water as raw materials. The carbon dot material of this invention can achieve highly efficient whitening, brightening, and antibacterial effects when applied to fabrics.

Description

Technical Field

[0001] This invention belongs to the technical field of nanomaterials, and in particular relates to a carbon dot material with both whitening and antibacterial functions and its applications. Background Technology

[0002] Cotton fabrics, whether natural or synthetic, are not entirely white. Since ancient times, people have strived to eliminate the yellowish tint of white fabrics and visually enhance their whiteness and brightness. Optical brighteners are commonly used in the textile industry to whiten and brighten fabrics; moreover, they are frequently included in commercial detergent formulations to improve whiteness and enhance fabric color. Furthermore, due to their whitening and brightening properties, optical brighteners are also widely used in coatings, plastics, and paper. However, their poor water solubility and photostability limit their commercial application.

[0003] Carbon dots are ultra-small, zero-dimensional nanomaterials with a size of less than 10 nm. Due to their excellent optical properties, outstanding biocompatibility, attractive catalytic properties, ultra-small size, low toxicity, and environmental friendliness, carbon dots have been widely used in biomedicine, sensing, catalysis, optoelectronic devices, lubrication, and other fields. However, there are no reports in the current technology regarding the use of carbon dots as fluorescent whitening agents. Summary of the Invention

[0004] One of the objectives of this invention is to provide a carbon dot material that combines whitening and antibacterial functions.

[0005] A second objective of this invention is to provide a fluorescent whitening agent comprising the aforementioned carbon dot material.

[0006] A third objective of this invention is to provide applications of the aforementioned carbon dot materials.

[0007] To achieve the above objectives, the present invention adopts the following technical solution.

[0008] A carbon dot material with both whitening and antibacterial functions is characterized by being synthesized by a hydrothermal method using fluorescent whitening agent VBL, citric acid, copper chloride, ammonia, ethylenediamine, and water as raw materials.

[0009] The molecular formula of the fluorescent whitening agent VBL is C 36 H 34 N 12 O8S2Na2, CAS number 12224-16-7.

[0010] This invention uses the fluorescent whitening agent VBL, citric acid, and copper chloride as precursors for hydrothermal synthesis to obtain a multifunctional carbon dot material, VBL-CDs; specifically:

[0011] ① The carbon dot material VBL-CDs of the present invention has a similar fluorescence absorption and emission spectrum to the fluorescent whitening agent VBL (hereinafter referred to as VBL), can emit blue fluorescence, and exhibits superior optical properties than VBL, such as strong fluorescence brightness and excellent fluorescence stability;

[0012] ② Through ingenious precursor selection, this invention enables VBL-CDs to possess antibacterial properties that ordinary fluorescent whitening agent VBL does not have, and at the same time has a highly effective antibacterial effect against both Gram-positive and Gram-negative bacteria.

[0013] ③Based on the characteristics of carbon dots, VBL-CDs also have good biocompatibility and exhibit good water solubility that VBL does not have.

[0014] Preferably, the mass ratio of the solid raw material fluorescent whitening agent VBL, citric acid and copper chloride is 2-3:7-9:1; the volume ratio of the liquid raw material ammonia, ethylenediamine and water is 45-55:45-55:1.

[0015] Preferably, the ratio of the solid raw material to the liquid raw material is 230-260 mg: 1 mL, that is, the mass-to-volume ratio of the material and liquid in the reaction system is 230-260 mg: 1 mL.

[0016] Preferably, the hydrothermal reaction temperature is 180–200°C and the reaction time is 2–5 h.

[0017] Further, the product obtained by hydrothermal synthesis is post-processed to obtain VBL-CDs. The post-processing steps are as follows: ultrapure water is added to the product obtained by hydrothermal synthesis, and the mixture is sonicated for 30 min; the solution obtained after sonication is purified by dialysis, and then freeze-dried to obtain a green powder, which is VBL-CDs.

[0018] The present invention does not impose a specific limitation on the amount of ultrapure water added to the above-mentioned product; as a specific embodiment, the amount of ultrapure water added is equal to or slightly greater than the product volume.

[0019] Furthermore, the dialysis purification involves dialysis the sonicated solution with a dialysis bag containing a molecular weight cutoff of 500–3000 Da and ultrapure water for 4–10 hours, with the ultrapure water being replaced every 1–3 hours during the dialysis process.

[0020] The present invention also provides a fluorescent whitening agent comprising the above-mentioned carbon dot material VBL-CDs, which can effectively whiten, brighten and antibacterial fabrics.

[0021] The present invention also provides the application of the above-mentioned carbon dot material VBL-CDs or the above-mentioned fluorescent whitening agent in the preparation of fabric detergents or fabric care agents with whitening and brightening effects.

[0022] The present invention also provides the application of the above-mentioned carbon dot material VBL-CDs or the above-mentioned fluorescent whitening agent in the preparation of antibacterial fabric detergents or fabric care agents; the antibacterial properties include Gram-positive bacteria and Gram-negative bacteria.

[0023] Preferably, the amount of the carbon dot material VBL-CDs is 0.25-1.0% (owf), more preferably 0.5% (owf).

[0024] Compared with the prior art, the beneficial effects of the present invention are:

[0025] The carbon dot material VBL-CDs of this invention emits blue fluorescence and has strong fluorescence brightness and excellent fluorescence stability. Therefore, after embedding VBL-CDs into the surface of fabric, due to its high fluorescence intensity and fluorescence stability, VBL-CDs exhibits high efficiency and excellent durability comparable to VBL in whitening and brightening.

[0026] This invention, through ingenious precursor selection, endows VBL-CDs with highly efficient antibacterial properties. In vitro antibacterial results show that VBL-CDs have excellent antibacterial activity against both Gram-positive and Gram-negative bacteria, and fabrics treated with VBL-CDs also have effective antibacterial capabilities, with inhibition rates of 98% and 99% against Staphylococcus aureus and Escherichia coli, respectively.

[0027] Furthermore, experiments have shown that fabrics treated with the carbon dot materials VBL-CDs of this invention have good biocompatibility and exhibit satisfactory performance in terms of UV resistance.

[0028] The carbon dot material VBL-CDs of this invention can achieve highly efficient whitening, brightening, and antibacterial effects when applied to fabrics, providing a new approach to replace existing fluorescent whitening agents in the textile field. Therefore, the carbon dot material VBL-CDs of this invention can also be used in the preparation of fabric detergents and fabric care agents with whitening, brightening, and / or antibacterial effects. Attached Figure Description

[0029] Figure 1 In the diagram, a is the UV-Vis absorption spectrum of VBL and VBL-CDs; b is the normalized fluorescence emission spectrum of VBL and VBL-CDs; and c is the fluorescence emission spectrum of VBL-CDs in aqueous solution at different excitation wavelengths.

[0030] Figure 2 Comparison of fluorescence intensity between VBL-CDs and VBL at the same concentration (0.1 mg / mL).

[0031] Figure 3In the figure, a and b are fluorescence emission changes of VBL and VBL-CDs after 365nm irradiation, respectively, and c is the TR emission decay point and relative best-fit curve of VBL-CDs and VBL.

[0032] Figure 4 A comparison chart showing the whiteness values ​​of untreated cotton fabric, VBL-treated cotton fabric, VBL-CDs-treated cotton fabric, and the negative control group CDs-treated cotton fabric.

[0033] Figure 5 In Figure a, the fluorescence intensity change spectrum of the cotton fabric treated with VBL after ultraviolet irradiation is shown; in Figure b, the fluorescence intensity change spectrum of the cotton fabric treated with VBL-CDs after ultraviolet irradiation is shown; and in Figure c, the peak statistical curves of Figures a and b are shown.

[0034] Figure 6 Figures a and b show the antibacterial effects and inhibition rates of different concentrations of VBL-CDs aqueous solutions against Staphylococcus aureus and Escherichia coli.

[0035] Figure 7 A comparison of the inhibition rates of VBL-CDs, VBL, and different carbon dot materials against Staphylococcus aureus and Escherichia coli.

[0036] Figure 8 Figures a and b show the antibacterial effects and inhibition rates of cotton fabrics treated with different amounts of VBL-CDs against Staphylococcus aureus and Escherichia coli.

[0037] Figure 9 Cell viability of NIH / 3T3 cells treated with different fabric samples.

[0038] Figure 10 The survival rate of NIH / 3T3 cells after ultraviolet irradiation under different conditions. Detailed Implementation

[0039] The present invention will be further illustrated below with reference to specific embodiments, but the embodiments do not limit the present invention in any way. Simple parameter substitutions in the embodiments cannot be described one by one in the embodiments, but this does not limit the present invention. Any changes, modifications, substitutions, combinations, or simplifications made without departing from the spirit and principle of the present invention should be considered equivalent substitutions and should be included within the scope of the present invention.

[0040] All materials used in the following examples are commercially available products.

[0041] Example 1

[0042] The carbon dot material VBL-CDs of the present invention are synthesized through the following steps:

[0043] (1) Add 300mg of fluorescent whitening agent VBL, 800mg of citric acid and 100mg of copper chloride, as well as 2.5mL of ammonia water, 2.5mL of ultrapure water and 50μL of ethylenediamine to a 50mL polytetrafluoroethylene reactor, heat to 190℃ and react for 3h.

[0044] (2) After the system is cooled to room temperature, 5 mL of ultrapure water is added to the dark brown solution obtained from the reaction and sonicated for 30 min. Then, the solution obtained after sonication is dialyzed for 4 h using a dialysis bag with a molecular weight cutoff of 1000 Da. The ultrapure water is replaced every 2 h during the dialysis process to obtain the purified VBL-CDs solution. Then, it is freeze-dried to obtain green VBL-CDs solid powder.

[0045] Example 2

[0046] The carbon dot material VBL-CDs of the present invention are synthesized through the following steps:

[0047] (1) Add 300mg of fluorescent whitening agent VBL, 800mg of citric acid and 100mg of copper chloride, as well as 2.5mL of ammonia water, 2.5mL of ultrapure water and 50μL of ethylenediamine to a 50mL polytetrafluoroethylene reactor, heat to 190℃ and react for 5h.

[0048] (2) After the system is cooled to room temperature, 5 mL of ultrapure water is added to the dark brown solution obtained from the reaction and sonicated for 30 min. Then, the solution obtained after sonication is dialyzed for 4 h using a dialysis bag with a molecular weight cutoff of 1000 Da. The ultrapure water is replaced every 2 h during the dialysis process to obtain the purified VBL-CDs solution. Then, it is freeze-dried to obtain green VBL-CDs solid powder.

[0049] Example 3

[0050] The carbon dot material VBL-CDs of the present invention are synthesized through the following steps:

[0051] (1) 250 mg of fluorescent whitening agent VBL, 850 mg of citric acid and 100 mg of copper chloride, as well as 2.4 mL of ammonia water, 2.6 mL of ultrapure water and 50 μL of ethylenediamine, were put into a 50 mL polytetrafluoroethylene reactor and heated to 180 °C for 4 h.

[0052] (2) After the system is cooled to room temperature, 6 mL of ultrapure water is added to the dark brown solution obtained from the reaction and sonicated for 30 min. Then, the solution obtained after sonication is dialyzed for 4 h using a dialysis bag with a molecular weight cutoff of 1000 Da. The ultrapure water is replaced every 2 h during the dialysis process to obtain the purified VBL-CDs solution. Then, it is freeze-dried to obtain green VBL-CDs solid powder.

[0053] Example 4

[0054] The carbon dot material VBL-CDs of the present invention are synthesized through the following steps:

[0055] (1) Add 300mg of fluorescent whitening agent VBL, 800mg of citric acid and 100mg of copper chloride, as well as 2.5mL of ammonia water, 2.5mL of ultrapure water and 50μL of ethylenediamine to a 50mL polytetrafluoroethylene reactor, heat to 190℃ and react for 4h.

[0056] (2) After the system is cooled to room temperature, 5 mL of ultrapure water is added to the dark brown solution obtained from the reaction and sonicated for 30 min. Then, the solution obtained after sonication is dialyzed for 5 h using a dialysis bag with a molecular weight cutoff of 500 Da. The ultrapure water is replaced every 1.5 h during the dialysis process to obtain the purified VBL-CDs solution. Then, it is freeze-dried to obtain green VBL-CDs solid powder.

[0057] Example 5

[0058] 1) Verify the fluorescence properties of VBL-CDs

[0059] like Figure 1 As shown in a and b, the UV-Vis absorption spectrum of a 0.1 mg / mL VBL-CDs aqueous solution, measured by a Meptop UV6100 UV-Vis spectrophotometer, shows that the maximum absorption occurs at 340 nm. Meanwhile, analysis using a Hitachi FL-7000 fluorescence spectrometer reveals that the optimal excitation wavelength of VBL-CDs (0.1 mg / mL) is 380 nm, with the emission center at 440 nm, which is very similar to the fluorescence spectrum of VBL, thus meeting the requirements for use as a fluorescent whitening agent. Figure 1 c represents the PL spectrum of VBL-CDs under different excitation wavelengths. As can be seen from the figure, when the excitation wavelength increases from 305 nm to 395 nm, VBL-CDs exhibit a single emission center and have excitation-independent characteristics.

[0060] like Figure 2 As shown, under the same concentration conditions (0.1 mg / mL), the fluorescence intensity of VBL-CDs is significantly stronger than that of VBL.

[0061] 2) Test the fluorescence stability of VBL-CDs

[0062] from Figure 3As shown in a and b, after irradiation with a 365nm UV lamp for 35 min, the fluorescence intensity of the VBL-CDs aqueous solution (0.1 mg / mL) did not decrease significantly, indicating that the prepared VBL-CDs have good resistance to photobleaching. Under the same conditions, the fluorescence intensity of the VBL aqueous solution (0.1 mg / mL) decreased significantly, only 4.7% of the original intensity (at 0 min).

[0063] The fluorescence lifetimes of VBL-CDs and VBLs were further compared, such as... Figure 3 As shown in c, the lifetime of VBL-CDs is significantly longer than that of VBL. Converting VBL into carbon dot materials VBL-CDs increases the average lifetime from 3.65 ns to 13.17 ns. Therefore, the VBL-CDs of this invention are expected to replace the fluorescent whitening agent VBL and be widely applied in various fields.

[0064] Example 6: Whitening and brightening effect of VBL-CDs on cotton fabrics

[0065] Identical cotton fabric samples (4g) were immersed in 200mL (approximately 200g) of VBL-CDs solutions with concentrations of 0.05mg / mL, 0.1mg / mL, 0.15mg / mL, and 0.2mg / mL, respectively. The corresponding VBL-CDs concentrations were 0.25%, 0.5%, 0.75%, and 1% (owf). The samples were stirred at room temperature for 1 hour, then removed, rinsed in cold water, and dried overnight at room temperature. The optical whitening effect was evaluated by measuring the whiteness index (WI) of the cotton fabric samples treated with different amounts of VBL-CDs using a colorimeter.

[0066] Following the above method, the whiteness index (WI) of cotton fabric samples treated with different amounts of VBL and CDs (where the synthesis steps of CDs and VBL-CDs in Example 1 are the same, but VBL was not used as a precursor) were measured as a comparison.

[0067] like Figure 4 As shown, when the dosage is 0.25% and 0.5%, compared with the untreated cotton fabric (Ctrl group) and the cotton fabric treated with CDs, the whiteness of the cotton fabric treated with VBL and VBL-CDs is significantly improved, and it can be seen that the whitening effect of VBL-CDs is comparable to that of VBL.

[0068] Meanwhile, cotton fabrics treated with VBL-CDs have better light stability and are more resistant to UV radiation than cotton fabrics treated with VBL. Figure 5 As shown, in other words, cotton fabrics treated with VBL-CDs have a more lasting whitening and brightening effect.

[0069] Example 7: Testing the antibacterial activity of VBL-CDs

[0070] This embodiment uses Gram-negative Escherichia coli (ATCC 29213) and Gram-positive Staphylococcus aureus (ATCC 25922). Single colonies of these two bacteria, cultured on solid media, were transferred to shake flasks containing LB liquid medium and incubated in a constant temperature shaker (37°C, 160 rpm) for 12 hours. After incubation, the bacterial culture was removed and diluted to 10⁻⁶. 6 CFU / mL, for later use.

[0071] In bacterial counting, the diluted bacterial solution (10) 6 CFU / mL samples were incubated with different concentrations of VBL-CDs aqueous solutions (25 μg / mL, 50 μg / mL, 100 μg / mL, 200 μg / mL) and VBL aqueous solution (200 μg / mL). After incubation at 37°C for 1 h, each sample was serially diluted with sterile PBS (pH = 7.4), and then plate counting was performed. The inhibition rate / antibacterial rate was then calculated: inhibition rate / antibacterial rate = (number of colonies in the control group - number of colonies in the treatment group) / number of colonies in the control group × 100%. The results are shown in the figure. Figure 6 (The control group refers to the diluted bacterial culture that was directly cultured.) Figure 6 (Displayed as Ctrl group in the middle).

[0072] Figure 6 The results showed that VBL-CDs at concentrations of 100 μg / mL and 200 μg / mL had excellent antibacterial activity against Escherichia coli and Staphylococcus aureus, while VBL had no antibacterial activity even at a concentration of 200 μg / mL.

[0073] Example 8: Testing the antibacterial effect of cotton fabric loaded with VBL-CDs (VBL-CDs / cotton)

[0074] In this embodiment, Gram-negative Escherichia coli (ATCC 29213) and Gram-positive Staphylococcus aureus (ATCC 25922) were used to test the antibacterial effect; the cotton fabric used in the experiment was 4g of cotton cloth.

[0075] First, single colonies of the two types of bacteria cultured on solid culture media were transferred to shake flasks containing LB liquid medium and incubated in a constant temperature shaker (37℃, 160 rpm) for 12 hours. Then, the bacterial culture was removed and diluted to 10⁻⁶. 6 CFU / mL, used for subsequent experiments.

[0076] Experiment 1: Comparison of the antibacterial effects of VBL-CDs, VBL, and different carbon dot materials

[0077] The experiments against Staphylococcus aureus and Escherichia coli were each divided into 5 groups:

[0078] (1) Ctrl group: Untreated cotton fabric;

[0079] (2) VBL group: Soak cotton cloth (4g) in 200mL of 0.1mg / mL VBL aqueous solution, the corresponding VBL dosage is 0.5% (owf), after 1h, rinse and air dry, cut into 4cm×2.5cm for subsequent experiments;

[0080] (3) CDs (VBL / CA / CuCl2) group: Cotton fabric was treated with the VBL-CDs aqueous solution synthesized in Example 1, and the treatment conditions were the same as those for the VBL group.

[0081] (4) CDs(CA / CuCl2) group: The carbon dot material was synthesized using the same steps as in Example 1, except that VBL was not used as a precursor. The cotton fabric was then treated with the carbon dot material solution under the same conditions as the VBL group.

[0082] (5) CDs(VBL / CA) group: The carbon dot material was synthesized using the same steps as in Example 1, except that CuCl2 was not used as a precursor. The cotton fabric was then treated with the carbon dot material solution under the same conditions as the VBL group.

[0083] Add the cotton samples from each group to a 6-well plate, and add 500 μL of Staphylococcus aureus and Escherichia coli bacterial suspension to each well, respectively. Incubate at 37°C for 6 hours. After incubation, remove the cotton samples and vortex thoroughly with 2 mL of Hank's balanced salt solution (HBSS buffer) for 2 minutes to completely wash away the bacteria. Then, dilute the bacterial suspension of each group 1000 times and spread it evenly on LB agar plates. After incubation, count the number of microbial colonies and calculate the inhibition rate. The results are shown in [Figure number missing]. Figure 7 .

[0084] like Figure 7 As shown, VBL-CDs have good antibacterial effects, and their antibacterial activity is significantly greater than that of untreated cotton fabric and VBL-treated cotton fabric. This indicates that VBL-CDs not only improve the whiteness of the fabric, but also endow the fabric with antibacterial function, realizing its multi-functional application.

[0085] Furthermore, from Figure 7 The results showed that only the CDs (VBL / CA / CuCl2) group could effectively inhibit the growth of Staphylococcus aureus and Escherichia coli simultaneously, that is, it has antibacterial function against both Gram-positive and Gram-negative bacteria; this indicates that the antibacterial function of VBL-CDs of the present invention is achieved through the synergistic effect of VBL, CA and CuCl2 as its synthetic precursors.

[0086] Experiment 2: Comparison of antibacterial effects of different dosages of VBL-CDs

[0087] The specific procedure was as follows: Cotton fabric samples were treated with 200 mL of VBL-CDs solutions at concentrations of 0.05 mg / mL, 0.1 mg / mL, 0.15 mg / mL, and 0.2 mg / mL, respectively, corresponding to VBL-CDs concentrations of 0.25%, 0.5%, 0.75%, and 1% (owf). Then, 500 μL of Staphylococcus aureus and Escherichia coli bacterial suspensions were added to each group of cotton fabric samples, and the samples were incubated at 37°C for 6 hours. After incubation, the bacteria were transferred from the fabric to 2 mL of phosphate buffer using a vortex method. Then, 100 μL of the mixture was inoculated onto an agar plate using the dilution plating method, spread evenly, and placed in a constant temperature incubator (37°C). The plate was inverted to prevent contamination. After 18 hours, the petri dishes were photographed, and the bacterial growth on each agar plate was recorded. Finally, the inhibition rate was obtained by counting the number of colonies.

[0088] like Figure 8 As shown in a and b, different dosages of VBL-CDs can effectively kill Staphylococcus aureus and Escherichia coli. Among them, 0.5% (owf) VBL-CDs has the best antibacterial effect, with inhibition rates of 98% and 99% against Staphylococcus aureus and Escherichia coli, respectively.

[0089] Example 9: Testing the biocompatibility and UV protection performance of VBL-CDs

[0090] 1) Biocompatibility of VBL-CDs

[0091] The cytotoxicity of VBL-CDs was studied using NIH / 3T3 fibroblasts.

[0092] NIH / 3T3 cells were seeded at a density of 5000 cells / well in 96-well plates and cultured for 24 h until cell attachment. Then, cotton fabric (0.5 × 0.5 cm) treated with VBL-CDs and VBL was placed in the wells. 2 Add the sample to a 96-well plate (one plate per well) and co-culture with NIH / 3T3 cells for 24 h; then add 10 μL of CCK-8 solution to the culture medium and incubate for 1.5 h; the absorbance of the sample is detected at 450 nm using a microplate reader (Tecan, Infinite F50, Switzerland).

[0093] Figure 9 The results showed that the cell survival rate on cotton fabrics treated with VBL-CDs and VBL was comparable to that on untreated cotton fabrics (Ctrl group) (no significant difference), with cell survival rates exceeding 90% in both groups, indicating good cell compatibility.

[0094] 2) UV protection performance

[0095] The protective effect of VBL-CDs-treated cotton fabrics against UV damage to the skin was further investigated using the CCK-8 test.

[0096] NIH / 3T3 cells were seeded at a density of 40,000 cells / well in 6-well plates and cultured for 24 h. The cells were then covered with aluminum foil (control group), untreated cotton fabric (blank group), cotton fabric treated with 0.5% (owf) VBL (VBL group), and cotton fabric treated with 0.5% (owf) VBL-CDs (VBL-CDs group). The unprotected group was designated as the UV group. The cells were then irradiated with 254 nm ultraviolet light for 1 h. After one day of further culture, the viability of NIH / 3T3 cells was assessed by CCK-8 assay.

[0097] Figure 10 The results showed that the VBL group and the VBL-CDs group provided satisfactory ultraviolet protection, with cell viability of 95.5% and 94.1%, respectively, while the unprotected (UV) group experienced approximately 20% cell death after ultraviolet irradiation.

Claims

1. A carbon dot material with both whitening and antibacterial functions, characterized in that, It is synthesized by hydrothermal method using fluorescent whitening agent VBL, citric acid, copper chloride, ammonia, ethylenediamine and water as raw materials; The mass ratio of the solid raw material fluorescent whitening agent VBL, citric acid, and copper chloride is 2~3 : 7~9 : 1; The volume ratio of the liquid raw materials ammonia, ethylenediamine, and water is 45-55: 45-55: 1; the ratio of the solid raw materials to the liquid raw materials is 230-260 mg: 1 mL. The hydrothermal reaction temperature is 180~200℃, and the reaction time is 2~5h.

2. The carbon dot material with both whitening and antibacterial functions according to claim 1, characterized in that, The product obtained by hydrothermal synthesis is post-processed; the post-processing steps are as follows: ultrapure water is added to the product obtained by hydrothermal synthesis and sonicated for 30 min; the solution obtained after sonication is purified by dialysis and then freeze-dried to obtain the carbon dot material.

3. The carbon dot material with both whitening and antibacterial functions according to claim 2, characterized in that, The dialysis purification process involves dialysis of the sonicated solution with a dialysis bag containing a molecular weight cutoff of 500-3000 Da and ultrapure water for 4-10 hours, with the ultrapure water being replaced every 1-3 hours during the dialysis process.

4. A fluorescent whitening agent comprising the carbon dot material of claim 1.

5. The use of the carbon dot material of claim 1 or the fluorescent whitening agent of claim 4 in the preparation of a fabric detergent or fabric care agent with whitening and brightening effects.

6. The use of the carbon dot material of claim 1 or the fluorescent whitening agent of claim 4 in the preparation of antibacterial fabric detergents or antibacterial fabric care agents.

7. The application according to claim 5 or 6, characterized in that, The amount of carbon dot material used is 0.25~1.0% owf.

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