Sn3O4 quantum dot nano-enzyme as well as preparation method and application thereof

Abstract

The invention discloses Sn3O4 quantum dot nano enzyme as well as a preparation method and application thereof, and belongs to the field of nano materials. The Sn3O4 quantum dot nano enzyme provided by the invention has a diameter of 5 nm to 30 nm. The Sn3O4 quantum dot nano-enzyme provided by the invention is Sn3O4 quantum dots formed by ultrasonic stripping of tristannic oxide nanosheets, and oxygen vacancies are introduced into Sn3O4 to improve the enzyme mimetic activity and antibacterial property of Sn3O4. According to the preparation method provided by the invention, ultrasonic treatment is utilized to promote further stripping and size reduction of the tristannic oxide nanosheets, so that the Sn3O4 quantum dots with oxygen vacancies are formed, and the preparation method is simple, environment-friendly, free of complex equipment or expensive reagents and suitable for large-scale production. The formed Sn3O4 quantum dots are rich in oxygen vacancies and can become active centers of nano-enzymes, so that the catalytic activity of the nano-enzymes is remarkably improved, and the Sn3O4 quantum dots have advantages in the fields of biological catalysis and antibiosis.

Description

Technical Field

[0001] The present invention relates to the field of nanomaterials, and particularly to a Sn3O4 quantum dot nanozyme and its preparation method and application. Background Art

[0002] As a material that mimics the activity of natural enzymes, nanozymes have found extensive applications in antibacterial, sensing and other fields due to their unique catalytic properties and high stability. Sn3O4 is a metal oxide with good photocatalytic properties and is widely used in environmental treatment and energy conversion. In recent years, it has been found that the introduction of oxygen vacancies in the Sn3O4 material can significantly improve its catalytic activity in catalytic reactions. However, the effect of the introduction of oxygen vacancies on the performance of Sn3O4 nanozymes is not yet clear. Summary of the Invention

[0003] In view of the above-mentioned disadvantages of the prior art, the purpose of the present invention is to provide a Sn3O4 quantum dot nanozyme and its preparation method and application. The obtained Sn3O4 quantum dot nanozyme can generate oxygen vacancies during the preparation process, has mimetic enzyme catalytic activity, and exhibits excellent antibacterial properties.

[0004] To achieve the above purpose or other purposes, the present invention provides a Sn3O4 quantum dot nanozyme, and the diameter of the Sn3O4 quantum dot nanozyme is 5 nm to 30 nm. The Sn3O4 quantum dot nanozyme of the present invention is formed by ultrasonic exfoliation of tin tetroxide nanosheets into Sn3O4 quantum dots, and the introduction of oxygen vacancies in Sn3O4 is used to enhance its mimetic enzyme activity and antibacterial properties.

[0005] Another aspect of the present invention also provides the application of the above Sn3O4 quantum dot nanozyme in sensing detection and the biomedical field.

[0006] The third aspect of the present invention provides a method for preparing the Sn3O4 quantum dot nanozyme, including the following steps:

[0007] (1) Take stannous chloride, sodium citrate, and sodium hydroxide, mix them, and stir evenly to obtain a tin precursor solution;

[0008] (2) Transfer the tin precursor solution to a reaction vessel, carry out a reaction, and obtain tin tetroxide nanosheets;

[0009] (3) Treat the product tin tetroxide nanosheets in step (2) to obtain a Sn3O4 quantum dot nanozyme.

[0010] In an example of the present invention, the molar ratio of stannous chloride, sodium citrate, and sodium hydroxide in step (1) is (0.2 - 2):(0.5 - 5):(8 - 80).

[0011] In an example of the present invention, in step (2), the reaction temperature is 150°C to 210°C, and the reaction time is 4 h to 20 h.

[0012] In an example of the present invention, in step (3), the treatment method sequentially includes resuspension with deionized water, ultrasonic treatment, washing, and drying.

[0013] In an example of the present invention, the power of the ultrasonic treatment is 100 W to 1000 W, and the ultrasonic time is 0.5 h to 10 h. Through the ultrasonic treatment, the tin oxide nanosheets can be further exfoliated and reduced in size to form Sn3O4 quantum dots with oxygen vacancies.

[0014] In an example of the present invention, the power of the ultrasonic treatment is 300 W to 500 W, and the ultrasonic time is 0.5 h to 1 h.

[0015] In an example of the present invention, the washing is carried out using a mixed solvent of deionized water and absolute ethanol.

[0016] In an example of the present invention, the drying temperature is 20°C to 100°C.

[0017] The Sn3O4 quantum dot nanozyme disclosed by the present invention has peroxidase activity, can catalyze low-concentration hydrogen peroxide to generate hydroxyl radicals, can efficiently destroy bacterial cell membranes and biological macromolecules, and has excellent broad-spectrum bactericidal performance. Through the preparation method provided by the present invention, by using ultrasonic treatment, the tin oxide nanosheets can be further exfoliated and reduced in size to form Sn3O4 quantum dots with oxygen vacancies. The preparation method is simple, environmentally friendly, does not require complex equipment or expensive reagents, and is suitable for large-scale production. The formed Sn3O4 quantum dots are rich in oxygen vacancies, can become the active center of the nanozyme, significantly improve the catalytic activity of the nanozyme, and make it have advantages in the fields of biocatalysis and antibacterial. Description of the Drawings

[0018] Figure 1 It is the X-ray diffraction (XRD) pattern of the Sn3O4 quantum dot nanozyme prepared in Example 1 of the present invention.

[0019] Figure 2 It is the transmission electron microscopy (TEM) image of the Sn3O4 quantum dot nanozyme prepared in Example 1 of the present invention.

[0020] Figure 3 It is the nanozyme activity test of the materials prepared in Examples 1-4 and Comparative Examples 1-4 of the present invention.

[0021] Figure 4 It is the electron spin resonance result of the Sn3O4 quantum dot nanozyme prepared in Example 1 of the present invention.

[0022] Figure 5This is the test result of the antibacterial properties of the materials prepared in Examples 1-4 and Comparative Examples 1-4 of the present invention. Detailed implementation mode

[0023] The following uses specific specific examples to illustrate the implementation mode of the present invention. Those skilled in the art can easily understand other advantages and effects of the present invention from the content disclosed in this specification. The present invention can also be implemented or applied through other different specific implementation modes. The details in this specification can also be modified or changed based on different viewpoints and applications without departing from the spirit of the present invention. It should be noted that, without conflict, the following embodiments and the features in the embodiments can be combined with each other. It should also be understood that the terms used in the embodiments of the present invention are for describing specific specific implementation schemes, rather than for limiting the protection scope of the present invention. The test methods without specific conditions noted in the following embodiments are usually carried out under conventional conditions or according to the conditions recommended by each manufacturer.

[0024] It should be noted that the terms such as "upper", "lower", "left", "right", "middle" and "one" cited in this specification are only for the convenience of clear narration, rather than for limiting the scope of implementation of the present invention. The change or adjustment of their relative relationship, without substantial change in technical content, should also be regarded as the scope of implementation of the present invention.

[0025] The present invention provides a Sn3O4 quantum dot nanozyme, and the diameter of the Sn3O4 quantum dot nanozyme is 5 nm to 30 nm. The Sn3O4 quantum dot nanozyme of the present invention is formed by ultrasonic exfoliation of tin tetroxide nanosheets, and the oxygen vacancies are introduced into Sn3O4 to enhance its pseudo-enzyme activity and antibacterial properties.

[0026] The Sn3O4 quantum dot nanozyme provided by the present invention has good application uses in the fields of sensing detection and biomedicine.

[0027] The method for preparing the Sn3O4 quantum dot nanozyme of the present invention includes the following steps.

[0028] (1) Take stannous chloride, sodium citrate, and sodium hydroxide and mix them. After stirring evenly, a tin precursor solution is obtained.

[0029] (2) Transfer the tin precursor solution to a reaction container and carry out a reaction to obtain tin tetroxide nanosheets.

[0030] (3) Treat the product tin tetroxide nanosheets in step (2) to obtain Sn3O4 quantum dot nanozyme.

[0031] In one embodiment, in step (1), the molar ratio of stannous chloride, sodium citrate, and sodium hydroxide is (0.2 - 2):(0.5 - 5):(8 - 80). If the molar ratio of stannous chloride, sodium citrate, and sodium hydroxide is too large or too small, Sn3O4 cannot be formed, and SnO2 or SnO is formed instead.

[0032] In one embodiment, in step (2), the reaction temperature is 150°C - 210°C, and the reaction time is 4h - 20h.

[0033] In one embodiment, the treatment method in step (3) sequentially includes resuspension with deionized water, ultrasonic treatment, washing, and drying, but is not limited to resuspension with deionized water, ultrasonic treatment, washing, and drying. Through resuspension with deionized water, the tin(IV) oxide nanosheets are dispersed. Then, ultrasonic treatment is carried out to further exfoliate and reduce the size of the tin(IV) oxide nanosheets, thereby forming Sn3O4 quantum dots with oxygen vacancies.

[0034] In one embodiment, the power of ultrasonic treatment is 100W - 1000W, and the ultrasonic time is 0.5h - 10h. Through ultrasonic treatment, the tin(IV) oxide nanosheets can be further exfoliated and reduced in size, thereby forming Sn3O4 quantum dots with oxygen vacancies. If the ultrasonic power is too low and the time is too short, the formed tin(IV) oxide nanosheets cannot be broken, and quantum dots cannot be formed, and they do not have enzyme activity. If the ultrasonic power is too high and the time is too long, the formed tin(IV) oxide is too fragmented and difficult to collect.

[0035] In one embodiment, the power of ultrasonic treatment is 300W - 500W, and the ultrasonic time is 0.5h - 1h.

[0036] During the washing process, the solvent used for washing can be a conventional solvent in the art, including but not limited to water and alcohol. In one embodiment, the washing is carried out using a mixed solvent of deionized water and absolute ethanol; the ratio of deionized water to absolute ethanol is not limited.

[0037] In one embodiment, the drying temperature is 20°C - 100°C.

[0038] The technical solutions of the present invention will be described in detail below through several specific examples and comparative examples. Unless otherwise specified, the raw materials and reagents used in the following examples are commercially available products or can be prepared by conventional methods in the art. Unless otherwise specified in the embodiments of the present invention, the detection methods used are conventional detection methods in the industry.

[0039] Example 1

[0040] (1) In terms of molar ratio, stannous chloride, sodium citrate, and sodium hydroxide are mixed in a ratio of 1:3:20, and after stirring evenly, a tin precursor solution is obtained;

[0041] (2) Transfer the tin precursor solution into a 50 mL reaction kettle and react at 200 °C for 10 h;

[0042] (3) Resuspend the reaction product with deionized water and perform ultrasonic treatment (power 500 W, time 1 h). Wash and dry the obtained product with deionized water and absolute ethanol to obtain a solid powder.

[0043] Example 2

[0044] (1) Mix stannous chloride, sodium citrate, and sodium hydroxide in a molar ratio of 2:5:30, and stir evenly to obtain a tin precursor solution;

[0045] (2) Transfer the tin precursor solution into a 50 mL reaction kettle and react at 180 °C for 12 h;

[0046] (3) Resuspend the reaction product with deionized water and perform ultrasonic treatment (power 500 W, time 1 h). Wash and dry the obtained product with deionized water and absolute ethanol to obtain a solid powder.

[0047] Example 3

[0048] (1) Mix stannous chloride, sodium citrate, and sodium hydroxide in a molar ratio of 2:3:20, and stir evenly to obtain a tin precursor solution;

[0049] (2) Transfer the tin precursor solution into a 50 mL reaction kettle and react at 180 °C for 18 h;

[0050] (3) Resuspend the reaction product with deionized water and perform ultrasonic treatment (power 500 W, time 1 h). Wash and dry the obtained product with deionized water and absolute ethanol to obtain a solid powder.

[0051] Example 4

[0052] (1) Mix stannous chloride, sodium citrate, and sodium hydroxide in a molar ratio of 2:5:8, and stir evenly to obtain a tin precursor solution;

[0053] (2) Transfer the tin precursor solution into a 50 mL reaction kettle and react at 180 °C for 12 h;

[0054] (3) Resuspend the reaction product with deionized water and perform ultrasonic treatment (power 300 W, time 0.5 h), and wash and dry the obtained product with deionized water and absolute ethanol to obtain a solid powder.

[0055] Example 5

[0056] The difference between this example and Example 1 is as follows: Stannous chloride, sodium citrate, and sodium hydroxide are mixed in a molar ratio of 2:5:80; in step (2), the reaction is carried out at 150 °C for 20 h, and in step (3), the ultrasonic treatment power is 100 W and the time is 10 h.

[0057] Example 6

[0058] The difference between this example and Example 1 is as follows: Stannous chloride, sodium citrate, and sodium hydroxide are mixed in a molar ratio of 0.2:1:8; in step (2), the reaction is carried out at 210 °C for 10 h, and in step (3), the ultrasonic treatment power is 1000 W and the time is 0.5 h.

[0059] Example 7

[0060] The difference between this example and Example 1 is as follows: Stannous chloride, sodium citrate, and sodium hydroxide are mixed in a molar ratio of 0.2:5:8; in step (2), the reaction is carried out at 210 °C for 4 h, and in step (3), the ultrasonic treatment power is 800 W and the time is 2 h.

[0061] Example 8

[0062] The difference between this example and Example 1 is as follows: Stannous chloride, sodium citrate, and sodium hydroxide are mixed in a molar ratio of 0.2:5:50; in step (2), the reaction is carried out at 200 °C for 15 h, and in step (3), the ultrasonic treatment power is 300 W and the time is 2 h.

[0063] Example 9

[0064] The difference between this example and Example 1 is as follows: Stannous chloride, sodium citrate, and sodium hydroxide are mixed in a molar ratio of 2:5:20; in step (2), the reaction is carried out at 160 °C for 8 h, and in step (3), the ultrasonic treatment power is 300 W and the time is 8 h.

[0065] Example 10

[0066] The difference between this example and Example 4 is as follows: Stannous chloride, sodium citrate, and sodium hydroxide are mixed in a molar ratio of 1:2:8; in step (2), the reaction is carried out at 180 °C for 10 h, and in step (3), the ultrasonic treatment power is 300 W and the time is 2 h.

[0067] Comparative Example 1

[0068] (1) In terms of molar ratio, stannous chloride, sodium citrate, and sodium hydroxide are mixed in a ratio of 1:3:20, and after stirring evenly, a tin precursor solution is obtained;

[0069] (2) Transfer the tin precursor solution into a 50 mL reaction kettle and react at 200 °C for 10 h. The obtained product is washed with deionized water and absolute ethanol and dried to obtain tin oxide nanosheets.

[0070] Comparative Example 2

[0071] (1) Mix stannous chloride, sodium citrate, and sodium hydroxide in a molar ratio of 1:3:20, and stir evenly to obtain a tin precursor solution;

[0072] (2) Transfer the tin precursor solution into a 50 mL reaction kettle and react at 200 °C for 10 h;

[0073] (3) Resuspend the reaction product with deionized water and perform ultrasonic treatment (power 50 W, time 10 min). The obtained product is washed with deionized water and absolute ethanol and dried to obtain a solid powder.

[0074] Comparative Example 3

[0075] (1) Mix stannous chloride, sodium citrate, and sodium hydroxide in a molar ratio of 2:5:8, and stir evenly to obtain a tin precursor solution;

[0076] (2) Transfer the tin precursor solution into a 50 ml reaction kettle and react at 100 °C for 12 h;

[0077] (3) Resuspend the reaction product with deionized water and perform ultrasonic treatment (power 300 W, time 0.5 h). The obtained product is washed with deionized water and absolute ethanol and dried to obtain a solid powder.

[0078] Comparative Example 4

[0079] (1) Mix stannous chloride, sodium citrate, and sodium hydroxide in a molar ratio of 0.2:5:100, and stir evenly to obtain a tin precursor solution;

[0080] (2) Transfer the tin precursor solution into a 50 mL reaction kettle and react at 180 °C for 12 h;

[0081] (3) Resuspend the reaction product with deionized water and perform ultrasonic treatment (power 300 W, time 0.5 h). The obtained product is washed with deionized water and absolute ethanol and dried to obtain a solid powder.

[0082] Performance Test

[0083] 1. Take the Sn3O4 quantum dot nanozyme prepared in Example 1 and perform powder X-ray diffraction (XRD) detection. The detection results are as Figure 1 shown. It can be seen from the figure that its crystal structure is tin oxide.

[0084] 2. Take the Sn3O4 quantum dot nanozyme prepared in Example 1 and perform transmission electron microscopy (TEM) detection. The detection results are as follows: Figure 2 As shown, it can be seen from the figure that the size of the quantum dots is between 5 nm and 20 nm.

[0085] 3. Respectively take 20 μg of the materials prepared in Examples 1-4 and Comparative Examples 1-4, add 20 μL of 40 mM 3,3',5,5'-tetramethylbenzidine (TMB) to 1 mL of acetic acid-sodium acetate buffer solution with a pH of 3.6, add 10 μL of 1 M H2O2 solution, shake well for 1 min, and then measure the absorbance at a wavelength of 652 nm under an ultraviolet-visible spectrophotometer. The peroxidase-like activity of the nanozyme material is reflected by the strength of the absorbance. The reason is that the peroxidase-like activity can decompose H2O2 to generate hydroxyl radicals, and the reaction between hydroxyl radicals and TMB will produce a blue product with an absorption peak at 652 nm. Therefore, the size of the enzyme activity can be illustrated by observing the absorption peak intensity at 652 nm. The measured absorbances of the systems added with the Sn3O4 quantum dot nanozymes of Examples 1-4 are 1.26, 1.30, 1.26, and 1.22 respectively, and the measured absorbances of the materials of Comparative Examples 1-4 are 0.03, 0.06, 0.08, and 0.07 respectively. Specifically, as shown in Figure 3 shown, from Figure 3 it can be seen that, compared with the comparative examples, the examples of the present invention have better peroxidase-like activity.

[0086] 4. Take the Sn3O4 quantum dot nanozyme prepared in Example 1 and perform electron spin resonance testing. The obtained results are as follows: Figure 4 As shown, it can be seen from the figure that the Sn3O4 quantum dots have oxygen vacancies.

[0087] 5. The antibacterial effect of the nanozyme material is determined by the plate counting method. The specific method is as follows: Prepare 1.0 mL of pH buffer solution containing Gram-negative bacterium Escherichia coli with a pH value of 5.4, and the bacterial concentration is 10 6 / ml. Respectively take 8 portions of the above-mentioned bacterial liquid, and add 100 μg of the molybdenum nitride nanomaterials of Examples 1 to 4 and Comparative Examples 1 to 4 and 50 μL of H2O2 (concentration 1 mM) to the above 8 portions of bacterial liquid respectively to prepare different bacterial liquid samples. After shaking well and standing for 30 min, then take the above different bacterial liquid samples for plate counting in turn to obtain the bacterial concentration C after sterilization. The material sterilization efficiency = (1 - C / 10 6 ) × 100%. After calculation, the sterilization efficiencies of Examples 1-4 are 97%, 100%, 94%, and 99% respectively, and the sterilization efficiencies of Comparative Examples 1-4 are 6%, 5%, 4%, and 4% respectively. Specifically, as shown in Figure 5 shown, Figure 5Statistical results of the bactericidal efficiency of different materials. It can be seen from the figure that the bactericidal effects of Examples 1-4 are all above 90%, and the bactericidal capabilities of the comparative examples are all lower than 10%.

[0088] In summary, it can be seen that the Sn3O4 quantum dot nanozyme of the present invention has peroxidase activity, can catalyze low-concentration hydrogen peroxide to generate hydroxyl radicals, and has excellent bactericidal performance.

[0089] The above embodiments are only used to exemplarily illustrate the principles and effects of the present invention, rather than to limit the present invention. Any person familiar with this technology can modify or change the above embodiments without departing from the spirit and scope of the present invention. Therefore, all equivalent modifications or changes completed by those with ordinary knowledge in the technical field without departing from the spirit and technical ideas disclosed by the present invention should still be covered by the claims of the present invention.

Claims

1. A Sn3O4 quantum dot nanozyme, characterized in that, The diameter of the Sn3O4 quantum dot nanozyme is 5 nm to 30 nm.

2. Application of the Sn3O4 quantum dot nanozyme according to claim 1 in the fields of sensing detection and biomedicine.

3. A method for preparing the Sn3O4 quantum dot nanozyme according to claim 1, characterized in that, It includes the following steps: (1) Take stannous chloride, sodium citrate, and sodium hydroxide and mix them. After stirring evenly, a tin precursor solution is obtained; (2) Transfer the tin precursor solution to a reaction vessel and carry out a reaction to obtain tin oxide nanosheets; (3) Process the product tin oxide nanosheets in step (2) to obtain Sn3O4 quantum dot nanozymes.

4. The method according to claim 3, characterized in that, In step (1), the molar ratio of stannous chloride, sodium citrate, and sodium hydroxide is (0.2 to 2):(0.5 to 5):(8 to 80).

5. The method according to claim 3, characterized in that, In step (2), the reaction temperature is 150 °C to 210 °C, and the reaction time is 4 h to 20 h.

6. The method according to claim 3, wherein In step (3), the processing method sequentially includes resuspension with deionized water, ultrasonic treatment, washing, and drying.

7. The method according to claim 6, wherein The power of the ultrasonic treatment is 100 W to 1000 W, and the ultrasonic time is 0.5 h to 10 h.

8. The method according to claim 7, wherein The power of the ultrasonic treatment is 300 W to 500 W, and the ultrasonic time is 0.5 h to 1 h.

9. The method according to claim 6, wherein The washing is carried out using a mixed solvent of deionized water and absolute ethanol.

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