Rapid biosynthesis method and antibacterial application of photo-thermal nano material (Cu, Co) Se2

Abstract

The invention relates to a rapid biosynthesis method and antibacterial application of a photo-thermal nano material (Cu, Co) Se2. The method comprises the following steps: step 1, culturing dissimilatory metal reducing bacteria in a culture medium to a platform earlier stage, and activating; 2, the activated dissimilatory metal reducing bacteria are inoculated into an anaerobic culture medium, then bivalent copper salt and selenite are added, and Cu2-xSe nanoparticles are synthesized through a reaction under the anaerobic condition; wherein x is equal to 0-1; 3, divalent cobalt salt continues to be added under the anaerobic condition, thalli are separated into supernate through differential centrifugation, sediment is collected, and (Cu, Co) Se2 nanoparticles are obtained; step 4, carrying out cell disruption treatment on the (Cu, Co) Se2 nanoparticles; the light absorption range and intensity of the original selenide are improved, the photo-thermal efficiency of the selenide is enhanced, and the photo-thermal metal nano material (Cu, Co) Se2 can be efficiently, rapidly and controllably synthesized by the synthesis method.

Description

Technical Field

[0001] The present invention relates to the technical field of photothermal bimetallic nanomaterials, and specifically relates to a rapid biosynthesis method and antibacterial application of a photothermal nanomaterial (Cu, Co)Se2. Background Art

[0002] The bio - self - assembly synthesis technology of copper chalcogenides (such as Cu 2-x Se) realizes the efficient and green preparation of materials through the extracellular electron transfer mechanism of dissimilatory metal - reducing bacteria. This method uses microorganisms as templates to regulate the growth of nanocrystals, overcoming the defects of high temperature, high pressure, and polluting reagents in traditional chemical synthesis. However, this biosynthetic method usually has problems such as a limited light absorption range and an antibacterial mechanism relying on the photothermal effect, and it is difficult to meet the requirements of complex application scenarios for the multifunctionality of materials. To solve the above problems, some studies have tried to regulate the optoelectronic properties of semiconductor nanomaterials through element doping. For example, using the solvothermal method to introduce transition metals (such as Fe, Co) into the Cu 2-x Se lattice can broaden its light response range and endow it with chemical catalytic activity. However, such chemical doping processes require high - temperature or strong acid / alkali conditions, resulting in the loss of microbial activity and being incompatible with the bio - self - assembly process.

[0003] Currently, Cu 2-x Se nanomaterials synthesized by the extracellular electron transfer mechanism of dissimilatory metal - reducing bacteria (such as Shewanella oneidensis) have achieved efficient and controllable bio - self - assembly preparation, solving problems such as low synthesis efficiency and many by - products caused by intracellular metabolic interference in traditional biosynthesis. However, this technology still has limitations such as narrow spectral absorption, a single antibacterial mechanism, and insufficient nanostructure regulation. Some studies have used Shewanella oneidensis to self - assemble and synthesize Cu 2-x Se nanoparticles with relatively high photothermal performance, but the biosynthesized copper chalcogenide Cu 2-x Se has a single component and lacks active regulation means for the energy band structure and surface chemical properties, resulting in limited light absorption range and antibacterial mechanism. Although progress has been made in the Cu 2-x Se synthesis technology based on microbial self - assembly, there are still difficulties in optimizing the energy band structure and carrier lifetime of materials in terms of material functionality and practical applications. Traditional chemical doping methods (such as introducing Fe 3+ ) by the solvothermal method require harsh conditions such as high temperature and organic solvents, which destroy the microbial activity and cannot be directly integrated into the bio - self - assembly process. Currently, there is no successful case of regulating the LSPR characteristics by metal ion doping in the biosynthetic system.

[0004] The prior art is limited by biocompatibility and metabolic pathway selectivity, and it is difficult to precisely introduce heterogeneous metal active sites while maintaining the structural integrity of the material. Although traditional post-doping methods (such as chemical impregnation) can indirectly achieve the introduction of Co 2+ , they are prone to damaging the fine structure of the biological template, resulting in uneven distribution or agglomeration of active sites. SUMMARY OF THE INVENTION

[0005] In order to overcome the above technical problems, the purpose of the present invention is to provide a rapid biological synthesis method and antibacterial application of a photothermal nanomaterial (Cu, Co)Se2. This method not only improves the light absorption range and intensity of the original selenide, but also enhances its photothermal efficiency, enabling the synthesis method to efficiently, rapidly, and controllably synthesize the photothermal metal nanomaterial (Cu, Co)Se2;

[0006] The present invention makes full use of the extracellular electron transfer ability of dissimilatory metal-reducing bacteria such as Shewanella oneidensis, and proposes a new method for rapidly doping divalent cobalt ions into copper-deficient selenides to synthesize biological nanomaterials on the basis of the extracellular synthesis of Cu 2-x Se nanoparticles.

[0007] In order to achieve the above purpose, the technical solution adopted by the present invention is:

[0008] A rapid biological synthesis method of a photothermal nanomaterial (Cu, Co)Se2, comprising the following steps:

[0009] Step 1: Cultivate dissimilatory metal-reducing bacteria in a medium until the early stationary phase and activate them;

[0010] Step 2: Inoculate the activated dissimilatory metal-reducing bacteria into an anaerobic medium, then add a divalent copper salt and selenite, and react under anaerobic conditions to synthesize Cu 2-x Se nanoparticles; where x = 0-1;

[0011] Step 3: Continuously add a divalent cobalt salt under anaerobic conditions, separate the bacterial cells by differential centrifugation in the supernatant, collect the precipitate, and obtain (Cu, Co)Se2 nanoparticles;

[0012] Step 4: In order to release and disperse the nanomaterials synthesized by microorganisms and maximize the contact area and photothermal effect between the nanomaterials and the target bacteria, the (Cu, Co)Se2 nanoparticles need to be subjected to cell disruption treatment, and then configured into (Cu, Co)Se2 nanomaterial solutions with different concentration gradients using ultrapure water as a solvent for standby.

[0013] Further, in step 1, a single colony is picked from the plate of dissimilatory metal-reducing bacteria and cultured in LB medium under aerobic conditions for 11-14 h to obtain a bacterial solution, and then the bacterial solution after the above aerobic culture is transferred to fresh LB medium at an inoculation ratio of 0.5%-2% and continuously cultured aerobically for 11-14 h.

[0014] Further, in step 2, the anaerobic medium is LB medium, and the LB medium contains 10 g / L tryptone, 5 g / L yeast extract and 10 g / L NaCl, with a pH value of 6.8-7.2. In actual use, it is sterilized after nitrogen aeration, and the aeration time is 30-40 min.

[0015] Further, in step 2, the inoculation density OD 600 of the dissimilatory metal-reducing bacteria is 2.0-3.0, and the concentrations of the divalent copper salt and selenite in the anaerobic medium are 0.3-0.9 mM. In the specific embodiment of the present invention, the concentrations of the divalent copper salt and selenite are 0.6 mM and 0.3 mM respectively.

[0016] Further, in step 3, the anaerobic culture time is 9-24 h.

[0017] Further, in step 3, the concentration of the divalent cobalt salt in the anaerobic medium is 0.3-0.9 mM. In the specific embodiment of the present invention, the concentration of the divalent cobalt salt is 0.6 mM.

[0018] Further, in step 3, the differential centrifugation speed range is 8000-12000 rpm for 6-10 min.

[0019] Preferably, the dissimilatory metal-reducing bacterium is Shewanella.

[0020] The Shewanella is Shewanella oneidensis, such as Shewanella oneidensis MR-1.

[0021] Preferably, the divalent copper salt is selected from one of water-soluble divalent copper salts such as copper chloride and copper sulfate, the selenite is selected from one of water-soluble selenites such as sodium selenite, and the divalent cobalt salt is selected from one of water-soluble divalent cobalt salts such as cobalt chloride and cobalt sulfate.

[0022] Preferably, in step 3, the reaction time under anaerobic conditions is 9-24 h, and the reaction is fully cultured at a constant temperature (30 °C) with shaking (200-300 rpm).

[0023] In step 4, the (Cu, Co)Se2 nanoparticles are subjected to cell disruption treatment at 400-800 w for 15-40 min.

[0024] In the present invention, a xenon light source is used to simulate the solar light source to test the photothermal effect and photothermal antibacterial effect of the photothermal nanomaterial (Cu, Co)Se2.

[0025] For the application of the bimetallic site photothermal nanomaterial (Cu, Co)Se2 of the present invention, the liquid obtained after crushing the photothermal material (Cu, Co)Se2 cells is mixed with ultrapure water to prepare a liquid material, and the liquid material is used as a photothermal antibacterial material.

[0026] The biosynthesized bimetallic (Cu, Co)Se2 nanomaterial of the present invention constructs a photothermal conversion framework with Cu vacancies as the core and a chemical kinetic reaction network of Co catalytic active centers through vacancy doping, and has broad-spectrum natural light capture and excellent photothermal performance. Therefore, the (Cu, Co)Se2 nanomaterial has both the effects of photothermal-chemical kinetic synergistic antibacterial and long-term inhibition of biofilms.

[0027] Specifically, it includes the following steps:

[0028] Step 1: Mix the photothermal material (Cu, Co)Se2 after cell crushing with an appropriate amount of pure water and stir evenly at room temperature to prepare a solution material, and conduct a photothermal heating performance test.

[0029] Step 2: Select a model strain for antibacterial testing, and use the liquid materials with different concentrations as antibacterial agents for photothermal antibacterial.

[0030] Further, in Step 1, for comparison, (Cu, Co)Se2 is respectively prepared into solutions of 0 (pure water), 20, 80, and 400 mg / L, and the photothermal heating performance test is carried out with a cycle of 600 seconds. The photothermal heating performance test records the temperature change amount at a recording point of 15 seconds.

[0031] Further, in Step 2, the concentration of the (Cu, Co)Se2 photothermal antibacterial agent is 20 mg / L, preferably 20 - 400 mg / L.

[0032] In the experiment of the present invention, the Gram-positive bacterium Bacillus subtilis is taken as a representative model strain to verify the broad-spectrum antibacterial performance of the material.

[0033] The illumination condition for the photothermal antibacterial experiment is 2 sunlight intensities.

[0034] In the photothermal heating test, the temperature change is recorded by a temperature sensor with an accuracy of 0.1 °C.

[0035] The cycle of the photothermal antibacterial experiment is 12 hours.

[0036] The beneficial effects of the present invention:

[0037] (1) The method for rapidly synthesizing (Cu, Co)Se2 by adding divalent cobalt ions proposed in the present invention is a one-step chemical doping outside the cell. The introduction of cobalt ions improves the optical and electrical properties of the material, and this method increases the light absorption range and intensity of the selenide. This cobalt doping has no obvious effect on the highly active metabolism of bacteria. Using this method, high-performance and high-purity (Cu, Co)Se2 nanoparticles can be obtained. (Cu, Co)Se2 nanoparticles start to form within 10 seconds after adding divalent cobalt, and the biosynthesis cycle is shortened to only within 9 hours. (Cu, Co)Se2 has good photothermal effects and photothermal stability and can be used as a photothermal nanomaterial.

[0038] (2) The present invention uses a microorganism-mediated in-situ cobalt doping process to endow copper cobalt selenide materials with broadband light capture (400–1200 nm) and NIR response characteristics while retaining the green advantages of biosynthesis. Its absorption range highly matches the solar spectrum, enabling efficient photothermal conversion driven by natural light without relying on external high-power lasers. The biosynthesis method proposed in the present invention still maintains absorption (absorbance > 0) in the range of 1000–1200 nm (NIR-II region), and the overall light capture ability is increased by about 30%.

[0039] (3) The bimetallic site photothermal nanomaterial proposed in the present invention has both photothermal-chemodynamic synergistic antibacterial and long-term biofilm inhibition functions in photothermal antibacterial, increasing the antibacterial efficiency to 99.94%, and has great performance advantages and practical application potential. Description of the Drawings

[0040] Figure 1 TEM image of the (Cu, Co)Se2 nanoparticles biosynthesized in Example 1.

[0041] Figure 2 ICP data of the biotransformed in the process of regulating the rapid synthesis of (Cu, Co)Se2 nanoparticles by Shewanella oneidensis strain in Example 1.

[0042] Figure 3 XRD pattern of the biological (Cu, Co)Se2 nanoparticles in Example 1.

[0043] Figure 4 UV-Vis diagram of (Cu, Co)Se2 and Cu 2-x Se synthesized in Example 1.

[0044] Figure 5 Photothermal heating-up diagram of the (Cu, Co)Se2 nanomaterial in the example within 600 seconds under xenon lamp irradiation.

[0045] Figure 6Colony density of Bacillus subtilis after 20 mg / L (Cu, Co)Se2 in Example 3 was irradiated with a xenon light source at 2.0 W / cm 2 light intensity for 12 h. Detailed implementation mode

[0046] The present invention will be further described in detail below with reference to the accompanying drawings.

[0047] The formation process of (Cu, Co)Se2 nanoparticles in the reaction system of the present invention is greener and more environmentally friendly than most existing chemical methods for synthesizing and doping materials. It does not involve toxic reagents, has a fast synthesis rate, and at the same time, (Cu, Co)Se2 has good water solubility, good photothermal performance, and high antibacterial efficiency. First, the present invention mediates Na2SeO3 by bacteria and then reduces it extracellularly with Cu 2+ to synthesize Cu 2-x Se nanoparticles extracellularly, and then Co 2+ chemically dopes extracellularly to complete the self-assembly of (Cu, Co)Se2 nanoparticles. Therefore, the biosynthesis mechanism of (Cu, Co)Se2 nanoparticles in this system is significantly different from traditional methods.

[0048] The following further describes a rapid and controllable biosynthesis method of a photothermal metal nanomaterial copper selenide provided by the present invention.

[0049] Example 1: Synthesis of (Cu, Co)Se2 nanoparticles by Shewanella oneidensis MR-1.

[0050] (1) Cultivation of Shewanella: Select the strain Shewanella oneidensis MR-1;

[0051] Inoculate the Shewanella strain into 50 mL of anaerobic LB medium and incubate it at 30 °C with constant shaking (200 rpm) for 12 hours to obtain a bacterial solution; transfer the bacterial solution to 200 mL of LB medium at a volume ratio of 1:10 and continue to activate it for 12 h under the same conditions to obtain a bacterial solution;

[0052] (2) Synthesis of Cu 2-x Se: Centrifuge and collect the obtained bacterial solution, wash it 2-3 times with LB medium and then resuspend it. Transfer the bacterial suspension (OD600 = 3) to the anaerobic LB system in step (1). Sequentially add 0.3 mM water-soluble selenite and 0.6 mM water-soluble divalent copper salt to the anaerobic system. Incubate at 30 °C with constant shaking at a speed of 200 rpm for 24 h to obtain Cu 2-x Se material;

[0053] (3) Rapid synthesis of (Cu, Co)Se2: Add 0.6 mM of water-soluble divalent cobalt salt to the anaerobic system. Black (Cu, Co)Se2 can be observed to start forming within 10 seconds. Incubate at a constant temperature of 30 °C with shaking at a speed of 200 rpm for 9 - 24 h to obtain the (Cu, Co)Se2 material;

[0054] The (Cu, Co)Se2 nanoparticles prepared in Example 1 have the characteristics of fast synthesis rate, short cycle, and good biocompatibility.

[0055] Example 2: Photothermal heating performance test of (Cu, Co)Se2

[0056] In this example, the (Cu, Co)Se2 obtained in Example 1 was used. First, centrifuge at 10000 g for 5 min, then wash 3 times with ultrapure water and perform ultrasonic fragmentation treatment (400 W, 30 min). Different concentrations of (Cu, Co)Se2 materials (20, 80, 400 mg / L) were prepared with the harvested (Cu, Co)Se2 and ultrapure water, and the control group was ultrapure water. A xenon light source was used to simulate natural light with an output power of 2.0 W / cm 2 , and the measurement duration was 600 seconds. As can be seen from the figure, a temperature rise of 32.15 °C can be achieved under the condition of low-concentration (Cu, Co)Se2, showing a photothermal effect. Example 3: Photothermal antibacterial performance test of (Cu, Co)Se2

[0057] In this Example 3, the 20 mg / L (Cu, Co)Se2 material obtained in Example 2 was used, and Bacillus subtilis was selected as the model strain for the photothermal antibacterial experiment. First, add a bacterial solution with an OD of 0.1 of Bacillus subtilis to 50 mL of LB medium, and then add 10 mL of 20 mg / L (Cu, Co)Se2. A xenon light source was used to simulate natural light with an output power of 2.0 W / cm 2 , and aerobic culture was carried out for 12 h of illumination. The control group was the aerobic culture of the bacterial solution with an OD of 0.1 of Bacillus subtilis added to 50 mL of LB medium and culture under dark conditions. The aerobic culture conditions in this example were 30 °C and 200 rpm.

[0058] Performance index tests were carried out on the biosynthesized (Cu, Co)Se2 nanomaterial rapidly prepared in Example 1:

[0059] Preparation of bacterial TEM characterization samples:

[0060] Take an appropriate amount of the solution synthesized in step (3) of Example 1, centrifuge at 6000 g for 5 min, and discard the supernatant. Fix with 2.5% glutaraldehyde at room temperature for 4 h, then dehydrate through ethanol with continuous concentration gradients. Place the dehydrated biological sample on a molybdenum grid with a carbon film for capturing TEM images and elemental analysis.

[0061] Figure 1 TEM images of (Cu, Co)Se2 nanomaterials biosynthesized at different time periods in Example 1. As can be seen from the figure, the (Cu, Co)Se2 nanomaterials are spherical particles evenly distributed outside the cells, without aggregation, and the particle size is 50 - 80 nm.

[0062] Spherical (Cu, Co)Se2 nanoparticles obtained by extracellular microbial synthesis method have a uniform particle size distribution in the range of 50 - 80 nm, without aggregation, and the surface dispersibility is controllable. The specific morphology of this material synergistically acts with the nanoscale, providing a high specific surface area and a high-density distribution of exposed active sites. At the same time, due to the particle dispersion stability, the performance decay caused by secondary aggregation is avoided. Combining the biocompatibility characteristics of extracellular synthesis, the material can be directly separated without complex purification steps, significantly reducing the production cost, and is suitable for large-scale applications in multiple fields such as photocatalysis and photothermal.

[0063] ICP-AES test of the concentrations of biotransformed Se and Cu elements:

[0064] Take an appropriate amount of the solution synthesized in step (3) of Example 1, centrifuge at 10000 g for 5 min, discard the supernatant, resuspend the precipitate with ultrapure water and wash it 4 - 5 times. Digest the obtained precipitate, add 4 mL of nitric acid and boil it at high temperature, then add 1 mL of perchloric acid. When thick white smoke appears in the digestion tube, the digestion ends. Fix the volume of the solution to 5 mL, and measure the concentrations of Se, Cu, and Co in the solution by ICP-AES.

[0065] Figure 2 The ICP-AES data results show that the molar ratio of Cu:Co:Se is 1.28:0.78:1, that is, the (Cu, Co)Se2 nanoparticles are synthesized in the present invention, and the corresponding data are shown in Table 2 below;

[0066] Table 2

[0067]

[0068] Figure 2 ICP data of biotransformation during the process of rapidly synthesizing (Cu, Co)Se2 nanoparticles regulated by Shewanella oneidensis strain in Example 1.

[0069] Sample preparation for XRD characterization:

[0070] For the (Cu, Co)Se2 material harvested in Example 1, first centrifuge the bacterial solution for 1 - 2 min (4000 - 5000 rpm), remove the supernatant, and place the collected solid precipitate in a freeze dryer for drying. Use an agate mortar to grind the dried solid into a uniform powder, and take an appropriate amount of the powder for X-ray diffraction analysis and characterization.

[0071] Figure 3 For the X-ray diffraction analysis and characterization of the (Cu, Co)Se2 synthesized in Example 1, by comparing with the standard card (#25 - 0253), it shows that the phase of the synthesized nanomaterial in the example is (Cu, Co)Se2, where the content ratio of Cu and Co is not fixed, that is, the molar mass ratio Cu:Se = Co:Se = 2:1.

[0072] Figure 4 For the UV-Vis diagrams of the (Cu, Co)Se2 and Cu 2-x Se synthesized in Example 1, by comparing the absorption spectra of (Cu, Co)Se2 and Cu 2-x Se in the range of 200 - 2500 nm, it shows that the synthesized (Cu, Co)Se2 in the example has the characteristics of broadband light trapping (400–1200 nm) and NIR response, which not only improves the absorption intensity of Cu 2-x Se in the near-infrared light region, but also has a wider light absorption range.

[0073] Figure 5 The shown is the photothermal heating-up diagram of the (Cu, Co)Se2 nanomaterial in Example 2 within 600 seconds under xenon light source irradiation. It can be seen from the attached figure that the temperature rise of the low-concentration (Cu, Co)Se2 nanomaterial can reach 32.2 °C within 600 seconds, showing excellent photothermal effect.

[0074] Figure 6 The shown is the colony density of Bacillus subtilis after 20 mg / L (Cu, Co)Se2 in Example 3 is irradiated under a xenon light source with an intensity of 2.0 W / cm 2 for 12 h. It can be seen from the attached figure that after the material treatment for 12 hours, the growth of the Bacillus subtilis colonies is significantly inhibited, and the antibacterial efficiency can reach 99.94%. Through a step-by-step bio-chemical coupling strategy, the present invention first uses microbial self-assembly to synthesize a Cu 2-x Se nano-precursor, and then realizes the efficient doping of Co 2+ through controllable ion exchange, which not only retains the low-defect framework of the biosynthesized material, but also endows it with the Co-Cu bimetallic synergistic activity, providing a new way to solve the long-term technical contradiction of the compatibility between functional doping and the biosynthetic framework.

Claims

1. A rapid biosynthesis method of a photothermal nanomaterial (Cu, Co)Se2, characterized in that, It includes the following steps: Step 1: Cultivate dissimilatory metal-reducing bacteria in a culture medium until the early stage of the plateau phase, and activate them. Step 2: Inoculate the activated dissimilatory metal-reducing bacteria into an anaerobic medium, then add divalent copper salts and selenite, and react under anaerobic conditions to synthesize Cu 2-x Se nanoparticles; where x = 0 - 1; Step 3: Under anaerobic conditions, continue to add divalent cobalt salt. Separate the bacterial cells in the supernatant by differential centrifugation, collect the precipitate, and obtain (Cu, Co)Se2 nanoparticles. Step 4: Perform cell disruption treatment on the (Cu, Co)Se2 nanoparticles, and then configure a (Cu, Co)Se2 nanomaterial solution using ultrapure water as a solvent.

2. The rapid biosynthesis method of a photothermal nanomaterial (Cu, Co)Se2 according to claim 1, characterized in that, In Step 1, pick single colonies from the plate of dissimilatory metal-reducing bacteria and culture them in LB medium under aerobic conditions for 11 - 14 h to obtain a bacterial solution. Then transfer the above-mentioned aerobically cultured bacterial solution to fresh LB culture medium at an inoculation ratio of 0.5% - 2% and continue aerobic culture for 11 - 14 h.

3. A rapid biosynthesis method of a photothermal nanomaterial (Cu, Co)Se2 according to claim 1, characterized in that, In Step 2, the anaerobic culture medium is LB medium, which contains 10 g / L tryptone, 5 g / L yeast extract, and 10 g / L NaCl, and the pH value is 6.8 - 7.

2.

4. A rapid biosynthesis method of a photothermal nanomaterial (Cu, Co)Se2 according to claim 1, characterized in that, In step 2, the inoculum density OD of dissimilatory metal-reducing bacteria 600 is 2.0 - 3.0, and the concentrations of the divalent copper salt and selenite in the anaerobic medium are 0.3 - 0.9 mM.

5. A rapid biosynthesis method of a photothermal nanomaterial (Cu, Co)Se2 according to claim 1, characterized in that, In Step 3, the anaerobic culture time is 9 - 24 h. In Step 3, the concentration of the divalent cobalt salt in the anaerobic culture medium is 0.3 - 0.9 mM.

6. A rapid biosynthesis method of a photothermal nanomaterial (Cu, Co)Se2 according to claim 1, characterized in that, In Step 3, the range of the differential centrifugation speed is 8000 - 12000 rpm.

7. A rapid biosynthesis method of a photothermal nanomaterial (Cu, Co)Se2 according to claim 1, characterized in that, The dissimilatory metal-reducing bacterium is Shewanella. The divalent copper salt is selected from one of water-soluble divalent copper salts such as copper chloride and copper sulfate, the selenite is selected from one of water-soluble selenites such as sodium selenite, and the divalent cobalt salt is selected from one of water-soluble divalent cobalt salts such as cobalt chloride and cobalt sulfate.

8. A rapid biosynthesis method of a photothermal nanomaterial (Cu, Co)Se2 according to claim 1, characterized in that, In Step 3, the reaction time under anaerobic conditions is 9 - 24 h, and the reaction is fully cultured by constant temperature oscillation (200 - 300 rpm).

9. A rapid biosynthesis method of a photothermal nanomaterial (Cu, Co)Se2 according to claim 1, characterized in that, In Step 4, perform cell disruption treatment on the (Cu, Co)Se2 nanoparticles at 400 - 800 w for 15 - 40 min.

10. Use of the obtained photothermal nanomaterial (Cu, Co)Se2 according to the method of any one of claims 1-9, characterized in that, Mix the liquid of the (Cu, Co)Se2 cell-disrupted photothermal material with ultrapure water to configure a liquid material, and use the liquid material as a photothermal antibacterial material. Specifically, it includes the following steps: Step 1: Mix the cell-disrupted (Cu, Co)Se2 photothermal material with an appropriate amount of pure water and stir evenly at room temperature to configure a solution material, and perform a photothermal heating performance test. Step 2: Select model strains for antibacterial testing, and use the different-concentration liquid materials as antibacterial agents for photothermal antibacterial. In Step 2, the concentration of the (Cu, Co)Se2 photothermal antibacterial agent is 20 - 400 mg / L, preferably 20 mg / L.

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