Amino silicon dioxide loaded metal palladium nano material as well as preparation method and application thereof

Abstract

The invention discloses an amino silicon dioxide loaded metal palladium nano material as well as a preparation method and application thereof. The antibacterial material with oxidase-like activity is prepared by taking amino-modified silicon dioxide as a carrier and metal palladium as an active center by adopting an excessive impregnation method. The amino silicon dioxide loaded metal palladium nano-material prepared by the invention is simple and easy to operate, safe and efficient, and the synthesized amino silicon dioxide loaded metal palladium nano-material can catalyze oxygen to generate active oxygen without additional auxiliary conditions (such as light, heat, electricity, hydrogen peroxide and the like). The bacteria structure is destroyed, so that the bacteria are effectively killed. The amino silicon dioxide loaded metal palladium nano material shows excellent antibacterial ability, and is expected to play an important role in solving the problem of bacterial drug resistance.

Description

Technical Field

[0001] The invention belongs to the technical field of antibacterial, and specifically relates to an aminosilica-loaded metal palladium nanomaterial, a preparation method and an application thereof. Background Art

[0002] Overuse of antibiotics has led to the emergence of bacterial resistance, which seriously threatens global public health security. How to resist bacterial infections while avoiding bacterial resistance has become a hot topic of concern. The misuse of antibiotics leads to bacterial gene mutations and the emergence of drug-resistant bacteria, which affects the treatment of bacterial infections. The rational use of antibiotics and the development of new antibacterial agents with high activity, high stability and low drug resistance to replace traditional antibiotics to achieve more efficient and widespread treatment of bacterial infections are urgent issues to be addressed.

[0003] In recent years, nanomaterials with oxidase-like and peroxidase-like properties have been explored for their potential in the field of antibacterial. They are characterized by simple use, high stability, low drug resistance, and strong activity. They can catalyze oxygen or hydrogen peroxide to produce reactive oxygen species, and the reactive oxygen species produced will act on bacteria to destroy cell structures, thereby causing bacterial death. At present, there are literature reports on a variety of nanozymes with enzyme-like properties, including carbon-based nanozymes, metal-based nanozymes, metal-organic framework nanozymes, etc. However, they still have problems such as high cost, complex synthesis process, and insufficient antibacterial effect. In addition, peroxidase-like nanozymes are dominant in antibacterial use, and hydrogen peroxide is required as a substrate during their operation, which is not only relatively complicated to operate but also has the potential to damage normal biological tissues. Summary of the invention

[0004] The purpose of the present invention is to develop an aminosilica-loaded metal palladium nanomaterial that has a simple synthesis method, significant effects, and does not require the addition of additional hydrogen peroxide, and can efficiently kill bacteria by catalyzing oxygen to produce active oxygen species.

[0005] To achieve the above purpose, the technical solution adopted by the present invention is as follows:

[0006] A kind of aminosilica loaded metal palladium nanomaterial, with amino-carrying silica sphere (SiO 2 -NH 2 ) as a carrier, and aminosilica-supported metal palladium nanomaterials (Pd / SiO 2 -NH 2 ).

[0007] Furthermore, in the aminosilica-loaded metal palladium nanomaterial, the palladium loading amount is 0.5% to 5% by mass.

[0008] Preferably, the aminosilica-loaded metallic palladium nanomaterial has a palladium loading of 2% by mass.

[0009] The method for preparing an aminosilica-supported metal palladium nanomaterial described in any one of the above comprises the following steps:

[0010] 1) dispersing aminosilica spheres in anhydrous ethanol, stirring with ultrasound to obtain a suspension, dripping the dispersion of palladium salt into the suspension at a uniform speed under stirring, stirring at room temperature for 4 hours, filtering, washing, and drying;

[0011] 2) the product obtained in step 1) is reacted with H 2 The reduction was carried out under the conditions for 1 hour to obtain amino silica loaded metal palladium nanomaterials.

[0012] Furthermore, in the above-mentioned preparation method, in step 1), the aminosilica spheres are silica spheres modified with 3-aminopropyltrimethoxysilane (APTES), and the palladium salt is palladium nitrate.

[0013] Furthermore, in the above preparation method, in step 2), the reduction temperature is 200°C.

[0014] The use of aminosilica-loaded metal palladium nanomaterials as an antibacterial agent in antibacterial applications as described in any one of the above.

[0015] Furthermore, in the above application, the bacteria are bacteria.

[0016] Furthermore, in the above application, the bacteria is Escherichia coli.

[0017] Furthermore, the above application method is as follows: aminosilica-loaded metal palladium nanomaterials are added to the bacterial suspension and shaken well.

[0018] Compared with the prior art, the present invention has the following advantages:

[0019] 1. The present invention adopts aminosilica-loaded metal palladium nanomaterial as nanozyme. The material has oxidase-like activity and can be applied in the antibacterial field. It has excellent antibacterial effect and the antibacterial rate can reach more than 99%.

[0020] 2. The present invention adopts aminosilica loaded metal palladium nanomaterial as nanozyme, and noble metal palladium as active center, which has strong catalytic activity and enhanced antibacterial effect.

[0021] 3. The present invention adopts aminosilica-loaded metal palladium nanomaterials as nanozymes. Aminosilica as a carrier can optimize the uniformity of metal palladium loading, enhance the catalytic activity and stability of the nanozymes while reducing costs.

[0022] 4. The present invention adopts aminosilica-loaded metal palladium nanomaterial as nanozyme. The nanozyme is prepared by an excess impregnation method, has a simple operation method, and is suitable for industrial production.

[0023] 5. The present invention uses aminosilica-loaded metal palladium nanomaterials as nanozymes. No auxiliary materials (such as hydrogen peroxide) need to be added. Active oxygen species can be generated for sterilization by catalyzing oxygen. The use process is green and efficient.

[0024] 6. The present invention uses aminosilica-loaded metal palladium nanomaterials as nanozymes, which have low toxicity and good biocompatibility, and have broad application prospects in many fields such as biomedicine.

[0025] In summary, the nano material of the present invention is to load metal palladium on the surface of a silica ball containing amino groups, with uniformly dispersed noble metal palladium as the active center, with the characteristics of enhancing catalytic efficiency, significantly reducing the amount of material used, and improving the antibacterial effect. The material can efficiently produce active oxygen without the need to add additional auxiliary conditions (light, heat, etc.) and substances (hydrogen peroxide, etc.) to achieve effective sterilization. The synthesis process and use method of the material are simple and easy, green and efficient, showing excellent catalytic antibacterial performance, and the material has low toxicity, and is expected to play an important role in many fields such as biomedicine, nanoenzyme catalysis and antibacterial. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] Figure 1 This is the TEM image of amino silica spheres, where A: 200nm; B: 20nm.

[0027] Figure 2 This is a TEM image of aminosilica-supported metal palladium nanomaterials, where A: 0.5% Pd / SiO 2 -NH 2 ; B: 2% Pd / SiO 2 -NH 2 ; C: 5% Pd / SiO 2 -NH 2 .

[0028] Figure 3 SiO 2 -NH 2 , 0.5% Pd / SiO 2 -NH 2 , 2% Pd / SiO 2 -NH 2 and 5% Pd / SiO 2 -NH 2 Infrared spectrum of .

[0029] Figure 4This is a characterization diagram of aminosilica-supported palladium nanomaterials using ascorbic acid (AA) to verify the generation of active oxygen, where A: AA is treated with 2% Pd / SiO 2 -NH 2 UV absorption spectra before and after treatment; B: AA after different loading amounts of Pd / SiO 2 -NH 2 Comparison of absorbance after treatment.

[0030] Figure 5 is the Pd / SiO ratio at different nanomaterial concentrations 2 -NH 2 The effect diagram of inactivating E. coli.

[0031] Figure 6 is Pd / SiO at different Pd contents 2 -NH 2 The effect diagram of inactivating E. coli.

[0032] Figure 7 The Pd / SiO with different loading amounts 2 -NH 2 The inactivation effect of Escherichia coli under the same Pd content, where A: blank; B: 0.5% Pd / SiO 2 -NH 2 Antibacterial effect diagram; C: 2% Pd / SiO 2 -NH 2 Antibacterial effect diagram; D: 5% Pd / SiO 2 -NH 2 Antibacterial effect diagram. DETAILED DESCRIPTION

[0033] In order to better understand the technical solution of the present invention, a specific embodiment is further described in detail, but the solution is not limited thereto.

[0034] Example 1 Aminosilica-supported metal palladium nanomaterial (I) The preparation method comprises the following steps:

[0035] 1) First, take 100 mg SiO 2 -NH 2 (3-aminopropyltrimethoxysilane modified silica spheres) were placed in a flask, 5 mL of anhydrous ethanol was added, and the mixture was dispersed by ultrasonication for 10 min to obtain SiO 2 -NH 2 Prepare a palladium nitrate solution with a palladium concentration of 10 mg / mL, take 0.2 mL and add it to a centrifuge tube containing 5 mL of anhydrous ethanol, and ultrasonicate to obtain a palladium dispersion. Under magnetic stirring, slowly drop the palladium dispersion onto the SiO 2 -NH 2The suspension was stirred at room temperature for 4 hours. Finally, the reaction solution was filtered, washed and dried to obtain a precursor (the palladium loading was 2 wt%).

[0036] 2) The precursor prepared in step 1) is placed in a quartz tube, placed in a tube furnace, and heated at 200°C and H 2 The reduction was carried out under the same conditions for 1 hour to obtain aminosilica-supported metal palladium nanomaterials, which were recorded as 2% Pd / SiO 2 -NH 2 , the mass percentage of palladium is 2%.

[0037] At the same time, according to the above preparation method, the amount of palladium nitrate added in step 1) was replaced by 0.05 mL and 0.5 mL, respectively, to obtain aminosilica-supported metal palladium nanomaterials with palladium contents of 0.5% and 5%, respectively, recorded as 0.5% Pd / SiO 2 -NH 2 and 5% Pd / SiO 2 -NH 2 .

[0038] (II) Characterization

[0039] Figure 1 SiO 2 -NH 2 TEM image of the carrier. It can be observed that the amino silica carrier presents a uniform spherical shape with uniform size.

[0040] Figure 2 Pd / SiO 2 -NH 2 TEM images of different Pd / SiO loadings. 2 -NH 2 The palladium in the solution is evenly dispersed on the aminosilica carrier without any large particles or agglomeration.

[0041] Figure 3 SiO 2 -NH 2 and different loading amounts of Pd / SiO 2 -NH 2 Infrared spectrum. After aminosilica beads were loaded with palladium, the absorption peak position and shape of the infrared spectrum did not change significantly, indicating that loading metal palladium had no effect on the carrier structure.

[0042] Example 2 Aminosilica-supported metal palladium nanomaterial Pd / SiO 2 -NH 2 Study on the ability to produce active oxygen

[0043] The Pd / SiO prepared in Example 1 with different loading amounts 2-NH 2 The samples were mixed evenly with the active oxygen probe ascorbic acid (AA), incubated in NaAc-HAc buffer at 37°C for 2 h, and centrifuged to remove the effect of the nanomaterials on the absorbance of the active oxygen probe. The changes in the absorbance of AA were detected using a UV-visible absorption spectrometer.

[0044] Figure 4 This is a characterization diagram of the production of active oxygen using ascorbic acid. The experimental results show that Pd / SiO 2 -NH 2 It has a strong ability to generate active oxygen, and 2% Pd / SiO 2 -NH 2 It has the strongest ability to produce active oxygen.

[0045] Example 3 Aminosilica-loaded metal palladium nanomaterial Pd / SiO 2 -NH 2 Application in antibacterial

[0046] Antibacterial test, including the following steps:

[0047] 1) Preparation of LB medium: weigh 1 g of sodium chloride, 1 g of peptone, and 0.5 g of yeast extract powder into a conical flask, add 100 mL of water, and adjust the pH to 7.2-7.4 with NaOH solution to obtain LB liquid medium; weigh 8.25 g of nutrient agar into a conical flask, add 250 mL of water, adjust the pH to 7.2-7.4 with NaOH solution, place in a 121°C pressure steam sterilizer for sterilization for 20 min, and pour into a culture dish to obtain a solid medium.

[0048] 2) Use an inoculation loop to pick up Escherichia coli (E. coli ATCC 15597), streak it on a solid culture medium, and culture it in a 37°C incubator for 12 hours. Pick a single colony and place it in a liquid culture medium, and culture it in a 37°C constant temperature oscillator for 10 hours to obtain a bacterial suspension.

[0049] 3) Take 5 mL of bacterial suspension in a centrifuge tube, centrifuge it at 8000r for 5 min, wash it twice with sodium acetate-acetic acid buffer solution (NaAc-HAc) with pH=4.5, add NaAc-HAc buffer solution to obtain NaAc-HAc bacterial suspension; dilute the bacterial suspension step by step with NaAc-HAc buffer solution to make the final dilution concentration of 5×10 5 cfu·mL -1 .

[0050] 4) Weigh 0.5% Pd / SiO 2 -NH 2 , 2% Pd / SiO 2 -NH 2and 5% Pd / SiO 2 -NH 2 In the centrifuge tube, 2 mL of NaAc-HAc buffer solution was added for ultrasonic dispersion to obtain a suspension with a material concentration of 0.5 mg / mL. Then a certain amount of the material suspension was added to a concentration of 5×10 5 cfu·mL -1 The bacterial suspension was thoroughly shaken and reacted in a constant temperature oscillator at 37°C for 2 hours. The reaction solution was diluted 100 times and 100 μL was taken to coat the culture dish. The culture dish was placed in a constant temperature incubator at 37°C for 12 hours, the growth of the colonies was observed, and the colonies were counted and the antibacterial rate was calculated.

[0051] Figure 5 0.5% Pd / SiO at different material concentrations 2 -NH 2 , 2% Pd / SiO 2 -NH 2 and 5% Pd / SiO 2 -NH 2 The effect diagram of inactivating E. coli. The experimental results show that Pd / SiO with higher Pd loading 2 -NH 2 The inactivation efficiency of E. coli was higher, but 5% Pd / SiO 2 -NH 2 The inactivation effect is comparable to that of 2% Pd / SiO 2 -NH 2 There is no obvious improvement.

[0052] Figure 6 0.5% Pd / SiO at different Pd contents 2 -NH 2 , 2% Pd / SiO 2 -NH 2 and 5% Pd / SiO 2 -NH 2 Inactivation effect of Escherichia coli. When the Pd content is controlled to be consistent, 2% Pd / SiO 2 -NH 2 The inactivation effect of E. coli is significantly better than that of 5% Pd / SiO 2 -NH 2 and 0.5% Pd / SiO 2 -NH 2 .

[0053] Figure 7 0.5% Pd / SiO 2 -NH 2 , 2% Pd / SiO 2 -NH 2and 5% Pd / SiO 2 -NH 2 Comparison of antibacterial effects under the same Pd content. A is blank; B is 0.5% Pd / SiO 2 -NH 2 Antibacterial effect diagram; C is 2% Pd / SiO 2 -NH 2 Antibacterial effect diagram; D is 5% Pd / SiO 2 -NH 2 Antibacterial effect diagram. Antibacterial experiments have found that 2% Pd / SiO 2 -NH 2 It has better antibacterial performance, and can achieve an antibacterial rate of more than 99% at low dosage and low cost. This fully demonstrates that the 2% Pd / SiO synthesized by the present invention 2 -NH 2 It has excellent antibacterial properties and has broad prospects in the field of catalytic antibacterial.

Claims

1. An aminosilica-supported metal palladium nanomaterial, characterized in that: Amino-silica-loaded metal palladium nanomaterial Pd / SiO2-NH2 is constructed with amino-carrying silica spheres SiO2-NH2 as carriers and palladium as active centers.

2. The aminosilica-supported metal palladium nanomaterial according to claim 1, characterized in that: In terms of mass percentage, the loading amount of palladium is 0.5% to 5%.

3. The aminosilica-supported metal palladium nanomaterial according to claim 2, characterized in that: The palladium loading is 2% by mass.

4. A method for preparing an aminosilica-supported metal palladium nanomaterial according to any one of claims 1 to 3, characterized in that: The steps include: 1) dispersing aminosilica spheres in anhydrous ethanol, stirring with ultrasound to obtain a suspension, dripping the dispersion of palladium salt into the suspension at a uniform speed under stirring, stirring at room temperature for 4 hours, filtering, washing, and drying; 2) reducing the product obtained in step 1) under H2 conditions for 1 hour to obtain aminosilica-supported metal palladium nanomaterials.

5. The preparation method according to claim 4, characterized in that: In step 1), the aminosilica spheres are silica spheres modified with 3-aminopropyltrimethoxysilane, and the palladium salt is palladium nitrate.

6. The preparation method according to claim 4, characterized in that: In step 2), the reduction temperature is 200°C.

7. Use of the aminosilica-loaded metal palladium nanomaterial described in any one of claims 1 to 3 as an antibacterial agent in antibacterial applications.

8. The use according to claim 7, characterized in that: The bacteria are bacteria.

9. The use according to claim 8, characterized in that: The bacteria is Escherichia coli.

10. The use according to claim 7, characterized in that: The method is as follows: add aminosilica-loaded metal palladium nanomaterials into the bacterial suspension and shake well.

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