Preparation method of tellurium-selenium nano heterojunction with photo-thermal performance and broad-spectrum antibacterial application of tellurium-selenium nano heterojunction

Abstract

The invention discloses a preparation method and broad-spectrum antibacterial application of a tellurium-selenium nano heterojunction with photo-thermal performance, and belongs to the field of nano material preparation. The preparation method of the tellurium-selenium nano heterojunction comprises the following steps: sequentially adding glutathione into a sodium tellurite solution for incubation and reducing coenzyme II for incubation under the condition of argon protection to obtain a tellurium precursor; adding the tellurium precursor into a sodium hydroxide solution to react to obtain a tellurium nanorod; adding glucose into the tellurium nanorod solution for reaction to obtain glucose-terminated tellurium nanorods; and adding a selenium precursor into the glucose-terminated tellurium nanorod solution, and reacting to obtain the tellurium-selenium nano heterojunction. The preparation method is simple, the reaction condition is mild, and the glutathione, the reducing coenzyme II and the glucose which are used are all green, non-toxic and good in biocompatibility. The tellurium-selenium nano heterojunction prepared by the method is excellent in photo-thermal performance, the photo-thermal conversion efficiency can reach 74%, and the tellurium-selenium nano heterojunction has broad-spectrum antibacterial activity.

Description

Technical Field

[0001] The present invention belongs to the field of nanomaterial preparation, and specifically relates to a preparation method of a tellurium-selenium nanoheterojunction with photothermal properties and its broad-spectrum antibacterial application. Background Art

[0002] Bacterial infectious diseases pose a persistent threat to global public health security and have been listed by the World Health Organization as one of the major challenges facing human health in the 21st century. The increasing misuse of antibiotics and the emergence of "superbugs" such as methicillin-resistant Staphylococcus aureus have posed a significant challenge to traditional antibiotic treatment. Against this backdrop, photothermal therapy (PTT), a novel antibacterial strategy, offers significant advantages due to its unique physical inhibitory mechanism. Its mechanism of action relies on the efficient absorption and energy conversion of near-infrared light by photothermal agents, inducing bacterial protein denaturation and membrane disruption through thermal effects. Compared to traditional antibiotic therapies, photothermal therapy can prevent the development of bacterial resistance while offering advantages such as non-invasiveness, a shorter treatment course, deep tissue penetration, and broad-spectrum antimicrobial properties.

[0003] Photothermal agents directly influence the antibacterial efficacy of photothermal therapy. Inorganic nanomaterials, due to their high surface area and tunable interfacial properties, can effectively interact with microbial systems, offering unique advantages in the antibacterial field. Tellurium (Te) nanomaterials are narrow-bandgap p-type semiconductors (Eg ≈ 0.35 eV). Their band structure endows them with strong near-infrared light absorption, making them widely used as highly efficient photothermal conversion agents. However, elemental Tellurium nanomaterials exhibit high cytotoxicity, necessitating improvements in their biocompatibility through surface ligands or core-shell structure design. Selenium (Se), an essential trace element in living organisms, exhibits ideal biocompatibility. Furthermore, Se nanomaterials possess anti-tumor, anti-inflammatory, and antibacterial properties. By constructing Tellurium-Selenium nanoheterojunctions, the formation of the heterostructure effectively promotes the directional migration of photogenerated electron-hole pairs, reduces the probability of carrier recombination, and thereby improves the material's photothermal conversion efficiency. Summary of the Invention

[0004] The purpose of the present invention is to overcome the shortcomings and deficiencies in the preparation of existing tellurium and selenium nanomaterials, provide a method for preparing a tellurium-selenium nanoheterojunction with photothermal properties, and provide applications of the tellurium-selenium nanoheterojunction.

[0005] The purpose of the present invention is achieved through the following technical solutions: The present invention provides a method for preparing a tellurium-selenium nanoheterojunction with photothermal performance, which comprises the following steps: (1) Preparation of tellurium nanorods The tellurium precursor is added into a sodium hydroxide solution, and the solution is stirred and reacted at 78-83 DEG C to obtain tellurium nanorods.

[0006] (2) Preparation of glucose-capped tellurium nanorods Glucose, a capping agent, is added to the tellurium nanorod solution and stirred to react to obtain glucose-capped tellurium nanorods. The two ends of the tellurium nanorods are the (001) crystal planes of the hexagonal tellurium. Glucose selectively adsorbs on the two ends of the tellurium nanorods, namely the (001) crystal planes, acting as a structure-directing agent to induce selenium to grow specifically on the two ends of the tellurium nanorods. At the same time, it acts as a reducing agent to reduce the Te formed by oxidation at the two ends of the tellurium nanorods. 4+ .

[0007] (3) Preparation of tellurium selenide nanoheterojunction The selenium precursor is added to the glucose-terminated tellurium nanorod solution obtained in step (2), and the mixture is stirred at 68-73° C. to react to obtain a tellurium-selenium nanoheterojunction.

[0008] In step (1), the tellurium precursor is preferably prepared by a method comprising the following steps: under argon protection, simulating the biochemical reaction of intracellular glutathione and reduced coenzyme II catalyzing the reduction of sodium tellurite, glutathione and reduced coenzyme II simulating the intracellular reduction process, reducing the tellurium in sodium tellurite to a low-valent state, and obtaining a tellurium precursor.

[0009] More preferably, the tellurium precursor is prepared by a method comprising the following steps: under argon protection, sequentially adding glutathione to a sodium tellurite solution and incubating for 25-35 seconds, followed by reduced coenzyme II for 50-70 seconds, to obtain the tellurium precursor. The sodium tellurite solution is preferably prepared by adding sodium tellurite to a Britton-Robinson buffer solution. The molar ratio of sodium tellurite, glutathione, and reduced coenzyme II is preferably 1:(4-5):(1-1.5).

[0010] In step (1), the concentration of the sodium hydroxide solution is preferably 0.01 to 0.02 mol / L, and the stirring reaction time is preferably 10 to 60 minutes. By varying the concentration of sodium hydroxide and the reaction time, tellurium nanorods of different particle sizes can be obtained. The higher the sodium hydroxide concentration, the shorter the tellurium nanorods. Meanwhile, as the reaction time increases, the length of the tellurium nanorods decreases.

[0011] In step (2), the molar ratio of glucose to tellurium is preferably (100-300):1, and the stirring reaction time is preferably 3-4 hours.

[0012] In step (3), the selenium precursor is preferably prepared by a method comprising the following steps: under argon protection, sodium selenite and glutathione are added to water and incubated for 8 to 12 minutes, glutathione is added again, and incubation is continued for 4 to 6 minutes to obtain the selenium precursor. The molar ratio of sodium selenite, the first added glutathione, and the second added glutathione is preferably 1: (4 to 5): (1 to 1.5). The incubation is preferably carried out at 36 to 37°C and 180 to 200 rpm.

[0013] In step (3), the stirring reaction time is preferably 55 to 65 minutes.

[0014] In the preparation method, the rotation speed of the stirring reaction is preferably 450-550 rpm; the reaction or incubation temperature, unless otherwise specified, is preferably 15-35° C., that is, the reaction or incubation is carried out at room temperature.

[0015] Preferably, the method for preparing the tellurium-selenide nanoheterojunction with photothermal performance comprises the following steps: (1) Preparation of tellurium nanorods Under argon protection, sodium tellurite was added to a BR buffer solution, followed by incubation with glutathione and reduced coenzyme II to obtain a tellurium precursor solution. The tellurium precursor solution was added to a sodium hydroxide solution and stirred at 78-83°C. After the reaction was completed, BR buffer solution was added to quench the reaction.

[0016] (2) Preparation of glucose-capped tellurium nanorods Glucose is added to the reaction system obtained in step (1), and the mixture is stirred to react to obtain glucose-capped tellurium nanorods.

[0017] (3) Preparation of tellurium selenide nanoheterojunction Under argon protection, sodium selenite and glutathione are added to water for incubation, and glutathione is added again for further incubation to obtain a selenium precursor solution. The selenium precursor solution is added to the reaction system obtained in step (2), stirred at 68-73°C for reaction, and the product is collected by centrifugation after the reaction is completed to obtain a tellurium selenide nanoheterojunction.

[0018] The present invention also provides a tellurium-selenide nanoheterojunction with photothermal properties, which is obtained by the above-mentioned preparation method.

[0019] The present invention also provides the application of the above-mentioned tellurium-selenide nanoheterojunction with photothermal properties in antibacterial applications, wherein the application is for non-disease treatment purposes.

[0020] The present invention also provides the use of the above-mentioned tellurium-selenide nanoheterojunction with photothermal properties in the preparation of antibacterial products.

[0021] The present invention also provides an antibacterial product, which comprises the above-mentioned tellurium selenide nanoheterojunction with photothermal properties.

[0022] The present invention has the following advantages and beneficial effects: The present invention provides a method for preparing tellurium-selenide nanoheterojunctions. The method is simple, employs mild reaction conditions, and utilizes glutathione, reduced coenzyme II, and glucose, all of which are green, non-toxic, and biocompatible. This method overcomes the shortcomings of existing chemical synthesis methods for nanomaterials, which rely on high temperature and high pressure conditions or contain toxic solvents. Glucose, acting as a structure-directing agent, adsorbs on the (001) crystal planes of tellurium nanorods, inducing the specific growth of selenium at both ends of the tellurium nanorods. By systematically regulating the concentration of the electrolyte sodium hydroxide and the reaction time, the length of the tellurium nanorods can be precisely controlled, thereby regulating the size of the tellurium-selenide nanoheterojunctions.

[0023] The tellurium selenide nanoheterojunctions prepared by this invention exhibit excellent photothermal performance, and their photothermal conversion efficiency is correlated with their size. A tellurium selenide nanoheterojunction with a length of 108 nm achieved a photothermal conversion efficiency of 74% under near-infrared laser (808 nm) irradiation. The tellurium selenide nanoheterojunctions prepared by this invention (4 μg / mL) were used in in vitro antibacterial experiments and demonstrated broad-spectrum antibacterial activity against Gram-positive Staphylococcus aureus and Gram-negative Escherichia coli after near-infrared laser irradiation, with inhibition rates of 92.76% and 95.67%, respectively. Furthermore, the tellurium selenide nanoheterojunctions significantly inhibited the growth of the highly pathogenic methicillin-resistant Staphylococcus aureus, with an inhibition rate of 94.76%. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1 Transmission electron micrographs of tellurium selenide nanoheterojunctions prepared according to the present invention. Scale: 100 nm. (a) Tellurium selenide nanoheterojunction reacted in 0.02 mol / L NaOH solution for 1 hour, (b) Tellurium selenide nanoheterojunction reacted in 0.01 mol / L NaOH solution for 1 hour, and (c) Tellurium selenide nanoheterojunction reacted in 0.01 mol / L NaOH solution for 10 minutes.

[0025] Figure 2 It is an X-ray diffraction pattern of the tellurium-selenide nanoheterojunction prepared by the present invention.

[0026] Figure 3 This is the EDS-mapping diagram of the tellurium-selenide nanoheterojunction prepared by the present invention.

[0027] Figure 4Figures 2 and 3 show the heating and cooling curves of the tellurium selenide nanoheterojunction prepared by the present invention under 808nm laser irradiation, along with a linear fit curve of t / lnθ during the cooling process. (a) Tellurium selenide nanoheterojunction reacted in 0.02mol / L NaOH solution for 1 hour, (b) Tellurium selenide nanoheterojunction reacted in 0.01mol / L NaOH solution for 1 hour, and (c) Tellurium selenide nanoheterojunction reacted in 0.01mol / L NaOH solution for 10 minutes.

[0028] Figure 5 This is a graph showing cell viability after incubation of the tellurium selenide nanoheterojunction prepared by the present invention with mouse fibroblasts (L929) and mouse breast cancer cells (4T1) for 24 hours.

[0029] Figure 6 Figure 1 shows the in vitro antibacterial effect of the tellurium-selenide nanoheterojunction prepared in this invention on Staphylococcus aureus. (a) Agar plate photos of Staphylococcus aureus colonies from different experimental groups, and (b) survival rate statistics.

[0030] Figure 7 Figure 1 shows the in vitro antibacterial effect of the tellurium selenide nanoheterojunction prepared by the present invention on Escherichia coli. (a) Agar plate photos of E. coli colonies from different experimental groups, (b) survival rate statistics.

[0031] Figure 8 Figure 1 shows the in vitro antibacterial effect of the tellurium-selenide nanoheterojunction prepared in this invention on methicillin-resistant Staphylococcus aureus. (a) Agar plate photos of methicillin-resistant Staphylococcus aureus colonies from different experimental groups, and (b) survival rate statistics. DETAILED DESCRIPTION

[0032] The following examples are used to further illustrate the present invention, but should not be construed as limiting the present invention. Unless otherwise specified, the technical means used in the examples are conventional means well known to those skilled in the art.

[0033] Example 1 Preparation of Tellurium Selenide Nanoheterojunction (length 108nm): (1) Preparation of tellurium precursor: 3 mL of Britton-Robison (BR) buffer solution (pH = 7.1) was deoxygenated by passing argon for 30 minutes. 28 μL of 0.1 mol / L sodium tellurite solution was added thereto, followed by 11.2 μmol of glutathione. The mixture was mixed well and incubated at room temperature for 30 seconds. 2.8 μmol of reduced coenzyme II was then added, and the mixture was incubated at room temperature for 1 minute to prepare a tellurium precursor solution.

[0034] (2) Preparation of tellurium nanorods: 11 mL of 0.02 mol / L sodium hydroxide solution was added to a three-necked flask, argon was introduced for 30 minutes to remove oxygen, and the temperature was raised to 80°C. The tellurium precursor solution prepared in step (1) was quickly injected into the three-necked flask, and the solution was stirred at 80°C for 1 hour. The color of the solution gradually changed from colorless to gray-black. After the reaction was completed, 8 mL of BR buffer solution was added to the system to quench the reaction.

[0035] (3) Preparation of glucose-capped tellurium nanorods: 840 μmol of glucose was added to the tellurium nanorod solution prepared in step (2), and the mixture was stirred at room temperature for 3 h.

[0036] (4) Preparation of selenium precursor: 22.4 μmol of glutathione was added to 1 mL of ultrapure water. After deoxygenation by purging with argon for 30 minutes, 5.6 μmol of sodium selenite was added and the mixture was incubated at 37°C with constant stirring for 10 minutes. Subsequently, 5.6 μmol of glutathione was added to the system and the mixture was incubated for another 5 minutes to prepare a selenium precursor solution.

[0037] (5) Preparation of tellurium selenide nanoheterojunctions: The glucose-capped tellurium nanorod system obtained in step (3) was heated to 70°C, and the selenium precursor solution prepared in step (4) was rapidly injected into a three-necked flask. The mixture was stirred at 70°C for 1 h to obtain tellurium selenide nanoheterojunctions (TeSeNDs). After the reaction, the reaction solution was rapidly cooled to 0°C, and the product was collected by centrifugation at 14,000 rpm, washed three times with ultrapure water, and resuspended in ultrapure water.

[0038] Figure 1 (a) is a transmission electron micrograph of the tellurium selenide nanoheterojunction prepared in this example. Scale bar: 100 nm. Statistics show that the average length of the tellurium selenide nanoheterojunction is 108.8 ± 1.5 nm, and the average width is 15.5 ± 0.2 nm.

[0039] Figure 2 is the X-ray diffraction pattern of the tellurium-selenide nanoheterojunction prepared in this example, and the patterns correspond to the standard cards of hexagonal tellurium (PDF#04-001-3623) and monoclinic selenium (PDF#04-010-4322).

[0040] Figure 3 This is the EDS-mapping diagram of the tellurium-selenide nanoheterojunction prepared in this embodiment. It can be seen from the figure that the selenium signals at both ends of the tellurium-selenide nanoheterojunction are stronger, and the selenium signal in the middle is weaker.

[0041] Figure 4(a) shows the heating and cooling curves of the tellurium selenide nanostructured heterojunction fabricated in this example under 808nm laser irradiation, along with a linear fit curve showing the relationship between time and -ln(θ) during the cooling process. The tellurium selenide nanostructured heterojunction reaches a temperature of 65.3°C after 10 minutes of laser irradiation. The photothermal conversion efficiency of the material, calculated through fitting, is 74.0%.

[0042] Figure 5 Figure 2 shows cell viability after 24 hours of incubation with different concentrations of Tellurium Selenide nanoheterojunction solutions (0, 1, 2, 4, 6, and 8 μg / mL) in mouse fibroblasts (L929) and mouse breast cancer cells (4T1). When the Tellurium Selenide nanoheterojunction concentration reached 8 μg / mL, the relative viability of both cell types remained above 80%, demonstrating the low cytotoxicity of the Tellurium Selenide nanoheterojunction prepared in this example.

[0043] Example 2-3 The preparation method of Example 2-3 is the same as that of Example 1, wherein the sodium hydroxide concentration and reaction time in step (2) for preparing tellurium nanorods are shown in Table 1 below.

[0044] Table 1

[0045] Figure 1 (b) is a transmission electron micrograph of the tellurium selenide nanoheterojunction prepared in Example 2. Scale bar: 100 nm. Statistics show that its major diameter is 270.0 ± 1.4 nm, and its minor diameter is 13.3 ± 0.1 nm.

[0046] Figure 4 (b) is the heating and cooling curve of the tellurium selenide nanoheterojunction prepared in Example 2 under 808nm laser irradiation and the linear fitting curve of time and corresponding -ln(θ) during the cooling process. The fitting calculation shows that its photothermal conversion efficiency is 60.4%.

[0047] Figure 1 (c) is a transmission electron micrograph of the tellurium selenide nanoheterojunction prepared in Example 3. Scale bar: 100 nm. Statistics show that its major diameter is 427.0 ± 6.5 nm, and its minor diameter is 12.8 ± 0.3 nm.

[0048] Figure 4 (c) is the heating and cooling curve of the tellurium selenide nanoheterojunction prepared in Example 3 under 808nm laser irradiation and the linear fitting curve of time and corresponding -ln(θ) during the cooling process. The fitting calculation shows that its photothermal conversion efficiency is 61.6%.

[0049] Table 2 compares the photothermal conversion efficiency of the tellurium selenide nanoheterojunctions prepared in Examples 1, 2, and 3 with the commercial photoacoustic imaging contrast agent indocyanine green. The tellurium selenide nanoheterojunctions have excellent photothermal performance.

[0050] Table 2

[0051] Application Example 1 The tellurium selenide nanoheterojunction prepared in Example 1 was used for photothermal antibacterial treatment, and its antibacterial effect on Gram-positive Staphylococcus aureus, Gram-negative Escherichia coli, and methicillin-resistant Staphylococcus aureus was evaluated by plate count method.

[0052] Tellurium selenide nanoheterojunctions (4 μg / mL) were mixed with bacterial solution growing in the logarithmic phase and placed under near-infrared laser (808 nm, 1.5 W / cm 2 ) for 25 minutes. Bacterial cultures treated with tellurium-selenide nanoheterojunctions without laser irradiation and those treated with PBS served as controls. The cultures were diluted to an appropriate dilution and then plated on agar plates. The plates were then incubated on a shaker at 37°C for 24 hours. Finally, the plates were photographed and the colonies counted.

[0053] like Figure 6 As shown in the figure, there are significant differences in the antibacterial effects of each experimental group on Staphylococcus aureus. Only a few colonies survived in the laser-irradiated Tellurium Selenide nanoheterojunction group, and the bacterial survival rate was statistically 7.33%. In contrast, the bacterial survival rates of the PBS control group, the laser-irradiated PBS treatment group, and the Tellurium Selenide nanoheterojunction treatment group were 100%, 90.76%, and 79.48%, respectively. Similarly, Figure 7 As shown in the antibacterial experiment on Escherichia coli, the antibacterial effect of the laser-irradiated tellurium selenide nanoheterojunction group was the most significant, with the bacterial survival rate reduced to 4.33%, significantly lower than that of the other treatment groups (PBS group: 98.84%; PBS treatment group with laser irradiation: 93.66%; tellurium selenide nanoheterojunction treatment group alone: ​​85.50%). In addition, the experimental results on the common multidrug-resistant bacteria methicillin-resistant Staphylococcus aureus ( Figure 8 ) showed that the bacterial survival rate of the Tellurium Selenide nanoheterojunction group exposed to laser irradiation was only 5.24%. These results confirm the great potential of Tellurium Selenide nanoheterojunctions in photothermal antibacterial applications.

[0054] The above embodiments are only used to help illustrate the present invention. The implementation methods of the present invention are not limited to the above embodiments. Any other changes, modifications, substitutions, combinations, and simplifications that do not deviate from the spirit and principles of the present invention should be considered as equivalent replacement methods and are included in the scope of protection of the present invention.

Claims

1. A method for preparing a tellurium-selenide nanoheterojunction with photothermal properties, characterized in that: The following steps are involved: (1) Preparation of tellurium nanorods The tellurium precursor is added to a sodium hydroxide solution and stirred at 78-83°C to obtain tellurium nanorods; (2) Preparation of glucose-capped tellurium nanorods Adding capping agent glucose to the tellurium nanorod solution, stirring and reacting to obtain glucose-capped tellurium nanorods; (3) Preparation of tellurium-selenide nanoheterojunction The selenium precursor is added to the glucose-terminated tellurium nanorod solution obtained in step (2), and the mixture is stirred at 68-73° C. to react to obtain a tellurium-selenium nanoheterojunction.

2. The method for preparing a tellurium-selenide nanoheterojunction with photothermal performance according to claim 1, characterized in that: In step (1), the tellurium precursor is prepared by a method comprising the following steps: under argon protection, glutathione is sequentially added to a sodium tellurite solution and incubated for 25 to 35 seconds, and reduced coenzyme II is incubated for 50 to 70 seconds to obtain a tellurium precursor.

3. The method for preparing a tellurium-selenide nanoheterojunction with photothermal performance according to claim 2, characterized in that: The sodium tellurite solution is obtained by adding sodium tellurite to a BR buffer solution; the molar ratio of sodium tellurite, glutathione and reduced coenzyme II is 1: (4-5): (1-1.5).

4. The method for preparing a tellurium-selenide nanoheterojunction with photothermal performance according to claim 1, characterized in that: In step (1), the concentration of the sodium hydroxide solution is 0.01 to 0.02 mol / L, and the stirring reaction time is 10 to 60 minutes.

5. The method for preparing a tellurium-selenide nanoheterojunction with photothermal performance according to claim 1, characterized in that: In step (2), the molar ratio of glucose to tellurium is (100-300):

1.

6. The method for preparing a tellurium-selenide nanoheterojunction with photothermal performance according to claim 1, characterized in that: In step (3), the selenium precursor is prepared by a method comprising the following steps: under argon protection, sodium selenite and glutathione are added to water and incubated for 8 to 12 minutes, and glutathione is added again and incubated for another 4 to 6 minutes to obtain a selenium precursor; The molar ratio of sodium selenite, glutathione added for the first time, and glutathione added for the second time is 1: (4-5): (1-1.5).

7. The method for preparing a tellurium-selenide nanoheterojunction with photothermal performance according to claim 1, wherein: The following steps are involved: (1) Preparation of tellurium nanorods Under argon protection, sodium tellurite is added to a BR buffer solution, followed by sequential addition of glutathione and reduced coenzyme II for incubation to obtain a tellurium precursor solution; the tellurium precursor solution is added to a sodium hydroxide solution, stirred at 78-83°C for reaction, and after completion of the reaction, a BR buffer solution is added to quench the reaction; (2) Preparation of glucose-capped tellurium nanorods Adding glucose to the reaction system obtained in step (1), stirring and reacting to obtain glucose-capped tellurium nanorods; (3) Preparation of tellurium-selenide nanoheterojunction Under argon protection, sodium selenite and glutathione are added to water for incubation, and glutathione is added again for further incubation to obtain a selenium precursor solution; the selenium precursor solution is added to the reaction system obtained in step (2), and the reaction is stirred at 68-73°C. After the reaction is completed, the product is collected by centrifugation to obtain a tellurium selenide nanoheterojunction.

8. A tellurium-selenide nanoheterojunction with photothermal properties, characterized by: The method is obtained by the preparation method according to any one of claims 1 to 7.

9. Use of the tellurium selenide nanoheterojunction with photothermal properties as claimed in claim 8 in antibacterial applications or in the preparation of antibacterial products.

10. An antibacterial product, characterized in that: The invention comprises the tellurium-selenide nanoheterojunction with photothermal performance as claimed in claim 8.

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