Barium titanate / bismuth coated polypyrrole nano material with antibacterial and imaging functions as well as preparation method and application of barium titanate / bismuth coated polypyrrole nano material

Abstract

The invention provides a barium titanate / bismuth coated polypyrrole nano material with antibacterial and imaging functions and a preparation method and application thereof. Comprising the following steps: S1, preparing barium titanate by a hydrothermal method; s2, loading elemental bismuth on the surfaces of the barium titanate nanoparticles to construct a barium titanate / bismuth heterojunction; and S3, in an ice-water bath, compounding the barium titanate / bismuth heterojunction with a pre-oxidized pyrrole monomer to prepare the barium titanate / bismuth coated polypyrrole nano material. The barium titanate / bismuth coated polypyrrole nano material prepared by the method has good biocompatibility and excellent antibacterial and imaging performance, can be used in the fields of wound or bone defect repair and the like, can realize non-invasive, efficient and controllable antibacterial performance, and can be used for real-time monitoring.

Description

Technical Field

[0001] The present invention belongs to the field of medical nanomaterials, and relates to a barium titanate / bismuth@polypyrrole nanomaterial with antibacterial and imaging functions, a preparation method thereof, and an application thereof. Background Art

[0002] The repair of infectious tissue defects is a major clinical problem. Clinically, the method of combining surgical debridement and antibiotics is generally used for treatment. On the one hand, it further enhances the bacterial drug resistance, stimulates the generation of super bacteria, and may lead to the situation that there is no drug available for super bacteria; on the other hand, repeated debridement and the large amount of antibiotics used also have continuous adverse effects on human tissue cells, reduce the treatment effect, easily cause tissue necrosis, and even cause death. Therefore, exploring effective and safe solutions without antibiotics is of great significance for the treatment of bacterial diseases.

[0003] So far, various drugs and materials have been developed, such as metal ions and antimicrobial peptides, to inhibit or reduce the growth of harmful bacteria. Among them, photothermal therapy (PTT) is a new technology. This technology converts light energy into local heat energy through a photothermal agent, and high temperature destroys the denaturation of bacterial proteins, damages the cell membrane, damages DNA / RNA, or disintegrates the biofilm formed by bacteria to achieve the purpose of sterilization. In addition, research shows that a certain electric stimulation can effectively reduce the formation of bacterial biofilms and dissolve the bacterial membrane to kill bacteria. However, the above single antibacterial methods have various problems, with poor treatment effects and single functions. Summary of the Invention

[0004] The purpose of the present invention is to provide a barium titanate / bismuth@polypyrrole nanomaterial with antibacterial and imaging functions, a preparation method thereof, and an application thereof, aiming to solve the above technical problems.

[0005] To solve the above technical problems, the present invention provides a preparation method of a barium titanate / bismuth@polypyrrole nanomaterial with antibacterial and imaging functions, including the following steps:

[0006] S1. Add a sodium hydroxide solution to titanium dioxide, mix well, fully react at high temperature, then add a hydrochloric acid solution, slowly stir, centrifuge and wash, then add a barium hydroxide solution, further carry out a hydrothermal reaction, centrifuge and wash, and dry to obtain barium titanate powder;

[0007] S2. Add the barium titanate powder to a bismuth nitrate pentahydrate solution, mix well, add sodium borohydride powder to the mixed solution, fully react, centrifuge and wash, and dry to obtain a barium titanate / bismuth heterojunction;

[0008] S3. Pre-oxidize the pyrrole monomer with concentrated hydrochloric acid, then add the barium titanate / bismuth heterojunction to the pre-oxidized pyrrole mixture, mix well, add an oxidant, and stir the reaction thoroughly in an ice bath, followed by centrifugation, washing, and drying to obtain the barium titanate / bismuth@polypyrrole nanomaterial.

[0009] Further, the molar ratio of titanium dioxide, sodium hydroxide, hydrochloric acid, and barium hydroxide in step S1 is 1:(3.6 - 4):(0.6 - 0.8):(0.8 - 1).

[0010] Further, the concentration of the sodium hydroxide solution in step S1 is 0.8 - 1.2 mol / L, with water as the solvent; the concentration of the hydrochloric acid solution is 0.1 - 0.4 mol / L, with water as the solvent; and the concentration of the barium hydroxide solution is 0.1 - 0.3 mol / L, with water as the solvent.

[0011] Further, the temperature for the high-temperature reaction of titanium dioxide with the sodium hydroxide solution in step S1 is 200 - 280 °C, and the time is 12 - 48 h.

[0012] Further, the temperature for the hydrothermal reaction after adding the barium hydroxide solution in step S1 is 120 - 180 °C, and the time is 16 - 48 h.

[0013] Further, the molar ratio of barium titanate, bismuth nitrate pentahydrate, and sodium borohydride in step S2 is (0.5 - 0.8):(0.8 - 1.2):(18 - 22), and the concentration of bismuth nitrate pentahydrate is 0.01 - 0.03 mol / L.

[0014] Further, the concentration of the concentrated hydrochloric acid in step S3 is 0.8 - 1.5 mol / ml, with deionized water as the solvent; the volume ratio of the concentrated hydrochloric acid to the pyrrole monomer is 100:(1 - 2), and the pre-oxidation time is 5 - 20 min.

[0015] Further, the dosage of the barium titanate / bismuth heterojunction in step S3 is 0.8% - 1.2% of the solution mass.

[0016] Further, the oxidant is Fe(Ⅲ), and its dosage ratio to the pyrrole monomer is 1:(2 - 4).

[0017] Further, the ice bath temperature condition in step S3 is 0 - 4 °C, and the stirring time is 2 - 6 h.

[0018] Further, in step S1, it is mixed evenly by stirring for 20 - 50 min.

[0019] Further, steps S2 and S3 are mixed evenly by ultrasonic treatment for 20 - 30 min.

[0020] Furthermore, the centrifugal washing in steps S1, S2 and S3 refers to alternating centrifugal washing with anhydrous ethanol and deionized water for 4 times, wherein the centrifugal speed is 10,000 rpm for 6 to 10 min; and the drying refers to drying at 50 to 80° C. for 12 to 48 h.

[0021] The present invention also provides a barium titanate / bismuth@polypyrrole nanomaterial with antibacterial and imaging functions, which is prepared by the above-mentioned preparation method.

[0022] Compared with the prior art, the present invention has the following beneficial effects:

[0023] The present invention uses biocompatible barium titanate piezoelectric materials, bismuth-based responsive nanoparticles and polypyrrole conductive polymers as raw materials. Barium titanate has many advantages such as non-toxicity, harmlessness, high chemical inertness, easy availability, low cost, etc., and has excellent imaging properties. The bismuth element has a high atomic number. The barium titanate piezoelectric nanoparticles and bismuth metal single substance are used to construct a heterojunction, and the polypyrrole conductive polymer is wrapped, so that the obtained composite nanomaterial has good near-infrared light absorption, and can form a built-in electric field and photothermal effect under light, and the two work together to efficiently kill bacteria; and can be used for infrared thermal imaging and CT imaging.

[0024] (1) The barium titanate / bismuth@polypyrrole nanomaterial obtained by the present invention has good biocompatibility and easy performance adjustment. By controlling the component ratio and external illumination parameters (power, time), excellent electrical signal response and photothermal effect can be achieved, and bacteria can be killed quickly and efficiently.

[0025] (2) The barium titanate / bismuth@polypyrrole nanomaterial obtained in the present invention has good infrared thermal imaging effect, can be used as a contrast agent for CT imaging, and can realize real-time monitoring of traumatic tissue.

[0026] (3) The present invention is simple to prepare, low in price, and can be mass-produced. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the accompanying drawings required for use in the description of the embodiments of the present invention will be briefly introduced below. Obviously, the accompanying drawings in the following description are only some embodiments of the present invention. For ordinary technicians in this field, other accompanying drawings can be obtained based on these accompanying drawings without paying creative labor.

[0028] Figure 1 The barium titanate / bismuth@polypyrrole nanomaterial prepared in Example 1;

[0029] Figure 2 This is a CT image of the barium titanate / bismuth@polypyrrole nanomaterial prepared in Example 1 under an X-ray computed tomography machine;

[0030] Figure 3 It is the photothermal heating curve of the barium titanate / bismuth@polypyrrole nanomaterial prepared in Example 2 under near-infrared light illumination;

[0031] Figure 4 It is the statistical chart of the antibacterial effect of the barium titanate / bismuth@polypyrrole nanomaterial prepared in Example 3 against Escherichia coli;

[0032] Figure 5 It is the optical photograph of the plate coating of the bacterial liquid after co-culturing phosphate buffer (left) and barium titanate / bismuth@polypyrrole under light illumination (right) with Escherichia coli respectively;

[0033] Figure 6 It is the statistical chart of the antibacterial effect of the barium titanate / bismuth@polypyrrole nanomaterial prepared in Example 3 against Staphylococcus aureus;

[0034] Figure 7 It is the optical photograph of the plate coating of the bacterial liquid after co-culturing phosphate buffer (left) and barium titanate / bismuth@polypyrrole under light illumination (right) with Staphylococcus aureus respectively. Detailed implementation manners

[0035] In order to make the technical problems, technical solutions and beneficial effects to be solved by the present invention clearer and more understandable, the present invention will be further described in detail below with reference to the embodiments and the accompanying drawings. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not used to limit the present invention.

[0036] The embodiment of the present invention provides a preparation method of a barium titanate / bismuth@polypyrrole nanomaterial with antibacterial and imaging functions, including the following steps:

[0037] S1. Add sodium hydroxide solution to titanium dioxide, mix evenly, fully react at high temperature, then add hydrochloric acid solution, slowly stir, centrifuge and wash, then add barium hydroxide solution, further carry out hydrothermal reaction, centrifuge and wash, and dry to obtain barium titanate powder;

[0038] S2. Add the barium titanate powder into the bismuth nitrate pentahydrate solution, mix evenly, add sodium borohydride powder to the mixed solution, fully react, centrifuge and wash, and dry to obtain the barium titanate / bismuth heterojunction;

[0039] S3. Pre-oxidize pyrrole monomer with concentrated hydrochloric acid, then add the barium titanate / bismuth heterojunction into the pre-oxidized pyrrole mixed solution, mix evenly, add an oxidant, fully stir and react in an ice bath, centrifuge and wash, and dry to obtain the barium titanate / bismuth@polypyrrole nanomaterial.

[0040] Among them, the polypyrrole material is a commonly used photothermal agent with good biocompatibility and excellent electrical conductivity. Barium titanate is a widely used piezoelectric material, and bismuth is a biocompatible conductive metal that is inexpensive and easily available. The barium titanate / bismuth@polypyrrole nanomaterial with antibacterial and imaging functions described in the present invention has high photothermal conversion performance and electrical characteristics, and can achieve non-invasive, efficient, and controllable anti-infection; in addition, excellent photothermal imaging performance and CT imaging characteristics can be used for real-time monitoring of traumatized tissues. Therefore, it has broad application prospects.

[0041] Specifically, the molar ratio of titanium dioxide, sodium hydroxide, hydrochloric acid, and barium hydroxide in step S1 is 1:(3.6 - 4):(0.6 - 0.8):(0.8 - 1).

[0042] Specifically, the concentration of the sodium hydroxide solution in step S1 is 0.8 - 1.2 mol / L, the solvent is water, the concentration of the hydrochloric acid solution is 0.1 - 0.4 mol / L, the solvent is water, and the barium hydroxide solution is 0.1 - 0.3 mol / L, and the solvent is water.

[0043] Specifically, the temperature of the high-temperature reaction of titanium dioxide and sodium hydroxide solution in step S1 is 200 - 280 °C, and the time is 12 - 48 h.

[0044] Specifically, the temperature of the hydrothermal reaction after adding the barium hydroxide solution in step S1 is 120 - 180 °C, and the time is 16 - 48 h.

[0045] Specifically, the molar ratio of barium titanate, bismuth nitrate pentahydrate, and sodium borohydride in step S2 is (0.5 - 0.8):(0.8 - 1.2):(18 - 22), and the concentration of bismuth nitrate pentahydrate is 0.01 - 0.03 mol / L.

[0046] Specifically, the concentration of the concentrated hydrochloric acid in step S3 is 0.8 - 1.5 mol / ml, the solvent is deionized water, the volume ratio of the concentrated hydrochloric acid to the pyrrole monomer is 100:(1 - 2), and the pre-oxidation time is 5 - 20 min.

[0047] Specifically, the dosage of the barium titanate / bismuth heterojunction in step S3 is 0.8% - 1.2% of the solution mass.

[0048] Specifically, the oxidant is Fe(Ⅲ), and its dosage ratio to the pyrrole monomer is 1:(2 - 4).

[0049] Specifically, the ice bath temperature condition in step S3 is 0 - 4 °C, and stir for 2 - 6 h.

[0050] Specifically, in step S1, it is stirred and mixed evenly, and the time is 20 - 50 min.

[0051] Specifically, steps S2 and S3 are mixed by ultrasonic waves for 20 - 30 min.

[0052] Specifically, the centrifugal washing in steps S1, S2 and S3 means alternately centrifugally washing 4 times with absolute ethanol and deionized water, where the centrifugal speed is 10,000 revolutions per minute and the time is 6 - 10 min; the drying means drying at 50 - 80 °C for 12 - 48 h.

[0053] The embodiment of the present invention also provides a barium titanate / bismuth@polypyrrole nanomaterial with antibacterial and imaging functions, which is prepared by the above preparation method.

[0054] The following specifically introduces the present invention in combination with specific embodiments:

[0055] Example 1

[0056] Preparation of barium titanate / bismuth@polypyrrole nanomaterial:

[0057] (1) Add titanium dioxide (1.45 g) to 1 mol / L aqueous NaOH solution, stir and mix at room temperature for 30 min, transfer the reaction solution to a polytetrafluoroethylene liner, then put it into a stainless steel autoclave, and then heat at 240 °C for 24 h.

[0058] (2) The obtained product is alternately centrifugally washed 4 times with absolute ethanol and deionized water, where the centrifugal speed is 10,000 rpm and the time is 8 min to obtain a purified product. Add 0.2 mol / L HCl, stir slowly for 4 h, and then alternately centrifugally wash 4 times with absolute ethanol and deionized water, where the centrifugal speed is 10,000 rpm and the time is 8 min, and then dry at 60 °C for 12 h.

[0059] (3) Add the product of step (2) to 0.2 mol / L aqueous barium hydroxide octahydrate solution, mix well, and heat at 140 °C for 24 h to obtain barium titanate nanoparticles (BaTiO 3 powder).

[0060] (4) Weigh bismuth(III) nitrate pentahydrate and dissolve it in deionized water, stir for 15 min to obtain a 0.02 mol / L bismuth(III) nitrate pentahydrate solution, add 0.3 g of the above BaTiO 3 powder, and ultrasonically disperse for 15 min until the powder is evenly dispersed.

[0061] (5) Weigh 0.3 mol / L of sodium borohydride into the solution in step (4), stir and react for 10 min. After the reaction ends, immediately wash the material four times alternately with anhydrous ethanol and deionized water, with a centrifugation speed of 10,000 rpm and a time of 8 min, and dry it at 60 °C for later use to obtain the product, denoted as BaTiO 3 / Bi nanocomposite.

[0062] (6) Add pyrrole monomer (volume ratio of 100:1.5) to a hydrochloric acid solution with a concentration of 1 mol / mL, pre-oxidize for 10 min, and add 1 wt% BaTiO 3 / Bi nanocomposite, and disperse it evenly by ultrasonic wave.

[0063] (7) Add oxidant Fe(Ⅲ) (molar ratio to pyrrole monomer is 1:3), stir in an ice-water bath for 3 h, wash the material four times alternately with anhydrous ethanol and deionized water, with a centrifugation speed of 10,000 rpm and a time of 6 min, and dry it in a vacuum drying oven at 60 °C to obtain barium titanate / bismuth@polypyrrole nanomaterial.

[0064] Example 2

[0065] Preparation of barium titanate / bismuth@polypyrrole nanomaterial:

[0066] (1) Add titanium dioxide (1.45 g) to 0.8 mol / L of NaOH aqueous solution, stir and mix at room temperature for 20 min. Transfer the reaction solution to a polytetrafluoroethylene inner liner, then put it into a stainless steel autoclave, and then heat it at 200 °C for 48 h.

[0067] (2) Centrifuge and wash the obtained product 4 times alternately with anhydrous ethanol and deionized water, with a centrifugation speed of 10,000 rpm and a time of 6 min to obtain the purified product. Add 0.2 mol / L of HCl, stir slowly for 4 h, and then centrifuge and wash 4 times alternately with anhydrous ethanol and deionized water, with a centrifugation speed of 10,000 rpm and a time of 6 min, and then dry it at 50 °C for 48 h.

[0068] (3) Add the product in step (2) to 0.1 mol / L of barium hydroxide octahydrate aqueous solution, mix well, and heat at 120 °C for 48 h to obtain barium titanate nanoparticles.

[0069] (4) Weigh bismuth(Ⅲ) nitrate pentahydrate and dissolve it in deionized water, stir for 15 min to obtain a 0.01 mol / L bismuth(Ⅲ) nitrate pentahydrate solution, add 0.3 g of the above BaTiO 3 powder, and disperse it evenly by ultrasonic wave for 5 min until the powder is evenly dispersed.

[0070] (5) Weigh 0.15 mol / L of sodium borohydride into the solution in step (4), and stir for 10 min. Immediately after the reaction ends, wash the material four times alternately with absolute ethanol and deionized water, with a centrifugation speed of 10000 rpm and a time of 6 min, and dry it at 50 °C for later use to obtain the product, denoted as BaTiO 3 / Bi nanoheterojunction.

[0071] (6) Add pyrrole monomer (volume ratio 100:1) to a hydrochloric acid solution with a concentration of 0.8 mol / mL, pre-oxidize for 20 min, and add 0.8 wt% BaTiO 3 / Bi nanoheterojunction, and disperse it evenly by ultrasonic treatment.

[0072] (7) Add the oxidant Fe(Ⅲ) (molar ratio to pyrrole monomer is 1:2), stir in an ice-water bath for 2 h, wash the material four times alternately with absolute ethanol and deionized water, with a centrifugation speed of 10000 rpm and a time of 6 min, and dry it in a vacuum drying oven at 50 °C to obtain barium titanate / bismuth@polypyrrole nanomaterials.

[0073] Example 3

[0074] Preparation of barium titanate / bismuth@polypyrrole nanomaterials:

[0075] (1) Add titanium dioxide (1.45 g) to a 1.2 mol / L aqueous NaOH solution, stir and mix at room temperature for 50 min, transfer the reaction solution to a polytetrafluoroethylene inner liner, then place it in a stainless steel autoclave, and then heat it at 280 °C for 12 h.

[0076] (2) Wash the obtained product by centrifugation alternately with absolute ethanol and deionized water 4 times, with a centrifugation speed of 10000 rpm and a time of 10 min, to obtain the purified product. Add 0.4 mol / L HCl, stir slowly for 4 h, and then wash it by centrifugation alternately with absolute ethanol and deionized water 4 times, with a centrifugation speed of 10000 rpm and a time of 10 min, and then dry it at 80 °C for 12 h.

[0077] (3) Add the product in step (2) to a 0.3 mol / L aqueous solution of barium hydroxide octahydrate, mix well, and heat at 180 °C for 16 h to obtain barium titanate nanoparticles.

[0078] (4) Weigh bismuth(Ⅲ) nitrate pentahydrate and dissolve it in deionized water, stir for 15 min to obtain a 0.03 mol / L solution of bismuth(Ⅲ) nitrate pentahydrate, add 0.3 g of the above BaTiO 3 powder, and disperse it evenly by ultrasonic treatment for 30 min until the powder is uniformly dispersed.

[0079] (5) Weigh 0.4 mol / L of sodium borohydride into the solution in step (4), and stir the reaction for 30 min. After the reaction is completed, immediately wash the material four times alternately with absolute ethanol and deionized water. The centrifugation speed is 10,000 rpm and the time is 10 min, and then dry it at 80 °C for later use to obtain the product, denoted as BaTiO3 / Bi nanoheterojunction.

[0080] (6) Add pyrrole monomer (volume ratio is 100:2) to the hydrochloric acid solution with a concentration of 1.5 mol / mL, pre-oxidize for 5 min, and add 1.2 wt% BaTiO 3 / Bi nanoheterojunction, and disperse it evenly by ultrasonic wave.

[0081] (7) Add the oxidant Fe(Ⅲ) (the molar ratio to pyrrole is 1:4), stir in an ice-water bath for 6 h, wash the material four times alternately with absolute ethanol and deionized water. The centrifugation speed is 10,000 rpm and the time is 10 min, and place it in a vacuum drying oven at 50 °C for drying to obtain barium titanate / bismuth@polypyrrole nanomaterial.

[0082] Performance test:

[0083] Imaging performance test:

[0084] For the barium titanate / bismuth@polypyrrole nanomaterial synthesized in Example 1, its contrast performance under CT imaging inspection was detected. The synthesized barium titanate / bismuth@polypyrrole nanomaterial was configured into 0 g / mL, 0.05 g / mL, 0.1 g / mL, 0.2 g / mL, 0.4 g / mL, and detected respectively. As Figure 2 shown, it can be seen that as the concentration increases, the imaging becomes more obvious, indicating that the barium titanate / bismuth@polypyrrole nanomaterial shows good contrast effect in imaging detection.

[0085] Photothermal performance test:

[0086] For the barium titanate / bismuth@polypyrrole nanomaterial synthesized in Example 2, its good photothermal effect under light illumination conditions was detected.

[0087] The experimental method is as follows: The irradiation light source is an 808 nm near-infrared laser with a power of 1 W / cm 2 . The concentration gradient of barium titanate / bismuth@polypyrrole is 0, 0.01, 0.1, 1, 10 g / L, and the solvent is PBS solution. The light irradiation time for each concentration is 10 min, and the temperature is recorded at 0, 2, 4, 6, 8, 10 min of irradiation time. The results are as Figure 3 shown, it can be seen that as the light irradiation time prolongs, the temperature increases, and the higher its concentration, the more the temperature increases, indicating that barium titanate / bismuth@polypyrrole has good photothermal effect.

[0088] Antibacterial performance test:

[0089] Escherichia coli and Staphylococcus aureus were respectively selected to test the antibacterial effect of the barium titanate / bismuth@polypyrrole nanomaterial synthesized in Example 3. The experimental group was divided into four groups: blank control group, barium titanate / bismuth@polypyrrole group, light + blank control group, and light + barium titanate / bismuth@polypyrrole group. The material concentration was 100 μg / ml, and the bacterial suspension with a bacterial density of 1×10 4 CFU / ml was inoculated into a 48-well plate and co-cultured with the powder in a shaker for 4 h. Four parallel samples were set for each group. After spreading on the plate, the results were observed in an incubator for 12 h. As Figure 4 and Figure 5 shown, they are respectively the statistical chart and the plate control chart of the antibacterial rate of the blank control group and the barium titanate / bismuth@polypyrrole experimental group against Escherichia coli. As Figure 6 and Figure 7 shown, they are respectively the statistical chart and the plate control chart of the antibacterial rate of the blank control group and the barium titanate / bismuth@polypyrrole experimental group against Staphylococcus aureus. It can be seen from the figures that barium titanate / bismuth@polypyrrole has a certain antibacterial effect compared with the blank control without light, while under light conditions, the antibacterial rates against Escherichia coli and Staphylococcus aureus both reach more than 80%, indicating that barium titanate / bismuth@polypyrrole under light conditions has excellent antibacterial effects;

[0090] The above description is only a description of the preferred embodiments of the present invention, and does not limit the scope of the present invention in any way. Any changes and modifications made by those of ordinary skill in the art of the present invention based on the above disclosure shall fall within the protection scope of the claims.

Claims

1. A method for preparing barium titanate / bismuth@polypyrrole nanomaterials with antibacterial and imaging functions, characterized in that: The following steps are involved: S1. Add sodium hydroxide solution to titanium dioxide, mix well, react fully at high temperature, then add hydrochloric acid solution, slowly stir, centrifuge and wash, then add barium hydroxide solution, further hydrothermally react, centrifuge and wash, and dry to obtain barium titanate powder; S2. The barium titanate powder is added to the bismuth nitrate pentahydrate solution, mixed, sodium borohydride powder is added to the mixture, reacted fully, washed by centrifugation, and dried to obtain a barium titanate / bismuth heterojunction; S3. Pre-oxidize the pyrrole monomer with concentrated hydrochloric acid, then add the barium titanate / bismuth heterojunction to the pre-oxidized pyrrole mixture, mix well, add the oxidant, stir the reaction well in an ice bath, centrifuge and wash, and dry to obtain the barium titanate / bismuth@polypyrrole nanomaterial.

2. The preparation method according to claim 1, characterized in that: The molar ratio of titanium dioxide, sodium hydroxide, hydrochloric acid and barium hydroxide in step S1 is 1:(3.6-4):(0.6-0.8):(0.8-1).

3. The preparation method according to claim 1, characterized in that: In step S1, the concentration of the sodium hydroxide solution is 0.8-1.2 mol / L, and the solvent is water; the concentration of the hydrochloric acid solution is 0.1-0.4 mol / L, and the solvent is water; the concentration of the barium hydroxide solution is 0.1-0.3 mol / L, and the solvent is water.

4. The preparation method according to claim 1, characterized in that: The temperature of the high temperature reaction of titanium dioxide and sodium hydroxide solution in step S1 is 200-280° C. and the time is 12-48 hours. The temperature of the hydrothermal reaction after adding barium hydroxide solution in step S1 is 120-180° C. and the time is 16-48 hours.

5. The preparation method according to claim 1, characterized in that: The molar ratio of barium titanate, bismuth nitrate pentahydrate and sodium borohydride in step S2 is (0.5-0.8):(0.8-1.2):(18-22), and the concentration of bismuth nitrate pentahydrate is 0.01-0.03 mol / L.

6. The preparation method according to claim 1, characterized in that: The concentration of the concentrated hydrochloric acid in step S3 is 0.8-1.5 mol / ml, the solvent is deionized water, the volume ratio of the concentrated hydrochloric acid to the pyrrole monomer is 100:(1-2), and the pre-oxidation time is 5-20 min.

7. The preparation method according to claim 1, characterized in that: In step S3, the amount of the barium titanate / bismuth heterojunction is 0.8% to 1.2% of the mass of the solution, the oxidant is Fe(III), and the molar ratio of the amount thereof to the pyrrole monomer is 1:(2 to 4); the ice bath temperature is 0 to 4° C., and stirring is performed for 2 to 6 hours.

8. The preparation method according to claim 1, characterized in that: In step S1, the mixture is mixed by stirring for 20 to 50 minutes, and in steps S2 and S3, the mixture is mixed by ultrasound for 20 to 30 minutes.

9. The preparation method according to claim 1, characterized in that: The centrifugal washing in steps S1, S2 and S3 refers to alternating centrifugal washing with anhydrous ethanol and deionized water for 4 times, wherein the centrifugal speed is 10,000 rpm for 6 to 10 minutes; the drying refers to drying at 50 to 80°C for 12 to 48 hours.

10. A barium titanate / bismuth@polypyrrole nanomaterial with antibacterial and imaging functions, characterized in that: The preparation method is described in any one of claims 1 to 9.

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