Sterilization method based on Cu-CNv heterogeneous Fenton-like catalyst

Abstract

The invention relates to a sterilization method based on a Cu-CNv heterogeneous Fenton-like catalyst, the Cu-CNv is used as the catalyst, the heterogeneous Fenton-like advanced oxidation technology is used for inactivating antibiotic-resistant bacteria, the inactivation efficiency of a Cu-CNv heterojunction on escherichia coli containing the antibiotic-resistant bacteria within 40 min reaches 100%, the operation is simple, the catalyst stability is good, and the method is suitable for industrial production. The sterilization performance is excellent. The invention is mainly embodied in high efficiency, no toxicity and wide application. Experiments prove that the material has good sterilization performance.

Description

Technical Field

[0001] The invention relates to the field of sterilization methods, and in particular to a sterilization method based on a Cu-CNv heterogeneous Fenton-like catalyst. Background Art

[0002] With the widespread use of antibiotics, especially their abuse in medical treatment, agriculture and aquaculture, my country is a major producer and user of antibiotics, but the serious abuse has led to the rapid growth of drug resistance. Antibiotic pollution has become one of the global environmental problems. What is more serious is that the residues of antibiotics not only lead to the accumulation of antibiotics in water and soil, but also trigger the emergence of antibiotic-resistant strains, leading to the spread of microbial resistance and threatening public health and ecological security. Therefore, it is particularly important to study effective methods for sterilizing drug-resistant bacteria. Summary of the invention

[0003] The technical problem to be solved by the present invention is to provide a sterilization method based on Cu-CNv heterogeneous Fenton-like catalyst in view of the above shortcomings.

[0004] In order to solve the above technical problems, the present invention adopts the following technical solutions:

[0005] The sterilization method based on Cu-CNv heterogeneous Fenton-like catalyst comprises the following steps:

[0006] Step 1: preparing a Cu-CNv heterogeneous Fenton-like catalyst, specifically comprising the following steps:

[0007] Step 1.1: calcine urea at high temperature in a crucible to obtain gC 3 N 4 The sample was named CN;

[0008] Step 1.2: Add the fired CN to a mixture containing NaBH 4 After ultrasonic dispersion and stirring in deionized water, a CNv suspension was obtained;

[0009] Step 1.3: Cu(NO 3 ) 3 ·3H 2 After the O solution was added to the CNv suspension, it was ultrasonically dispersed for more than 5 min and then stirred on a magnetic stirrer for 3 h;

[0010] Step 1.4, after the reaction in the previous step is completed, the obtained product is centrifuged and washed multiple times with deionized water and ethanol, and dried to obtain a Cu-CNv heterogeneous Fenton-like catalyst;

[0011] Step 2: Add the Cu-CNv heterogeneous Fenton-like catalyst from the previous step into the sterilized solution containing Escherichia coli for sterilization.

[0012] Furthermore, the magnetic stirrer is a multi-station magnetic stirrer.

[0013] Furthermore, in step 1.2, NaBH 4 The volume of deionized water is 40 mL, NaBH 4 The concentration is 1 mol / L.

[0014] Furthermore, the mass fraction of CN in the CNv suspension is 0.8%.

[0015] Furthermore, in step 1.3, Cu(NO 3 ) 3 ·3H 2 The concentration of O solution is 0.05 mol / L and the volume is 800 μL.

[0016] The beneficial effects of the present invention are:

[0017] The Cu-CNv heterogeneous Fenton-like catalyst obtained by the present invention can achieve efficient removal of target bacteria, has high catalytic efficiency, and the inactivation rate of the Cu-CNv heterojunction on Escherichia coli containing resistance genes within 40 minutes is 100%. The operation is simple, the catalyst has good stability, and the sterilization performance is excellent. The present invention is mainly embodied in high efficiency, non-toxicity, and wide application. It has been confirmed by experiments that the material has good sterilization performance. And it has been proved by experiments that compared with monomer CN, Cu-CNv has a stronger inactivation efficiency, and the inactivation efficiency is 100% when the reaction is 40 minutes.

[0018] The present invention is described in detail below with reference to the accompanying drawings and embodiments. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 (A) shows the survival rate of drug-resistant Escherichia coli determined by plate counting method, and (B) shows the Cu-CNv / H 2 O 2 and CN / H 2 O 2 The sterilization effect of the system on Escherichia coli, (C) is Cu-CNv / H 2 O 2 and CN / H 2 O 2 The bar graph of the sterilization efficiency of the system against Escherichia coli shows that compared with the monomer CN material, the sterilization efficiency of the Cu-CNv composite material is significantly higher than that of the monomer CN material, and the sterilization efficiency is 100% after 40 minutes of reaction. DETAILED DESCRIPTION

[0020] The following examples are provided for a better understanding of the present invention, but are not intended to limit the present invention. The experimental methods in the following examples are conventional methods unless otherwise specified. The experimental materials used in the following examples are purchased from conventional biochemical reagent stores unless otherwise specified.

[0021] The preparation method of Cu-CNv Fenton catalyst includes the following steps:

[0022] Step 1: Place 10 g of urea in a crucible, set the initial temperature to 20 °C, heat for 106 min, heat up to 550 °C, hold for 2 h, hold at 550 °C, and heat at 5 °C / min. Collect gC 3 N 4 Sample (named CN);

[0023] Step 2: Take 0.4 g CN, 1 M NaBH 4 Add to 40 ml of deionized water and disperse ultrasonically for 5 min to obtain a CNv suspension;

[0024] Step 3: Add 800 μL 0.05 M Cu(NO 3 ) 3 ·3H 2 O was added to the CNv suspension obtained in step 2, and then stirred on a magnetic stirrer for 3 hours; after the reaction was completed, the obtained product was washed three times by centrifugation with deionized water and ethanol, and finally dried overnight in vacuum at 60°C (named Cu-CNv).

[0025] Sterilization experiment process:

[0026] Step 1, medium preparation: liquid LB medium (1 liter); tryptone 10g, yeast extract 5g, NaCl 10g, deionized water to 1L;

[0027] (Note: For solid culture medium, add 5g yeast, 10g NaCl, 10g tryptone, and 15g agar per 1L.)

[0028] Step 2, sterilization: sterilize the culture medium in a high pressure sterilizer at 121°C for 20 minutes;

[0029] Step 3, expansion culture: Place the sterilized LB medium on a clean bench and cool it to room temperature but do not solidify. Take 100mL of LB medium and place it in a conical flask, add 100μg / mL ampicillin, 60μg / mL kanamycin and 20μg / mL tetracycline, and add 200uL of E. coli. Note: The whole process should be carried out in a clean bench, and the alcohol lamp should be lit throughout the process to avoid bacterial contamination. Place the prepared culture medium in a constant temperature shaker at 37℃150r / min, and avoid light for 12h (the bacterial liquid should be in the form of quicksand).

[0030] Step 4: E. coli MG1655 was cultured overnight at 37°C in LB medium supplemented with 100 μg / mL ampicillin, 60 μg / mL kanamycin, and 20 μg / mL tetracycline. The bacterial solution was centrifuged at 7000 r / min for 3 min, and the precipitate was taken. The cell precipitate was then washed repeatedly with saline for two to three times. Finally, the obtained cell precipitate was resuspended in sterile saline, and the OD600 was adjusted to 0.6 and diluted tenfold before use (10 7 cfu / mL).

[0031] Step 5: Weigh 5 mg of Cu-CNv catalytic material and disperse it into a reactor containing 45 mL of E. coli. Before the inactivation experiment, stir for 5 min in a dark environment, and then add 10 μL of H 2 O 2 Solution (the experiment was carried out in the dark). At regular intervals, the reaction solution was taken out and diluted into 0.9% physiological saline of different gradient multiples.

[0032] Step 6: Take 20 μL of the degraded or original bacterial solution in step 5 and spread it on a plate, place it in a 37°C constant temperature incubator and culture it for 24 hours, then take it out for observation and counting.

[0033] like Figure 1 As shown in the figure, we tested the sterilization performance of Cu-CNv and CN materials, using Escherichia coli containing resistance genes as model bacteria, H 2 O 2 The addition amount was 10 μL. Figure (A) shows the survival rate of drug-resistant Escherichia coli determined by plate counting method, and Figure (B) shows the survival rate of drug-resistant Escherichia coli determined by plate counting method. 2 O 2 and CN / H 2 O 2 The sterilization effect of the system on Escherichia coli. Figure (C) shows the Cu-CNv / H 2 O 2 and CN / H 2 O 2 The sterilization efficiency of the system against Escherichia coli is shown in the bar graph. Compared with the monomer CN material, the sterilization effect of the Cu-CNv composite material is significantly higher than that of the monomer CN material, and the sterilization efficiency is 100% when the reaction time is 40 minutes.

[0034] The above is an example of the best implementation of the present invention, and the parts not described in detail are common knowledge of ordinary technicians in the field. The protection scope of the present invention shall be based on the content of the claims, and any equivalent transformation based on the technical enlightenment of the present invention is also within the protection scope of the present invention.

Claims

1. A sterilization method based on Cu-CNv heterogeneous Fenton-like catalyst, characterized in that: The following steps are involved: Step 1: preparing a Cu-CNv heterogeneous Fenton-like catalyst, specifically comprising the following steps: Step 1.1, calcining urea at high temperature in a crucible to obtain a g-C3N4 sample named CN; Step 1.2, adding the fired CN into deionized water containing NaBH4, and obtaining a CNv suspension after ultrasonic dispersion and stirring; Step 1.3, after adding the Cu(NO3)3·3H2O solution into the CNv suspension, ultrasonically disperse it for more than 5 min, and then stir it on a magnetic stirrer for 3 h; Step 1.4, after the reaction in the previous step is completed, the obtained product is centrifuged and washed multiple times with deionized water and ethanol, and then dried to obtain a Cu-CNv heterogeneous Fenton-like catalyst; Step 2: Add the Cu-CNv heterogeneous Fenton-like catalyst from the previous step into the sterilized solution containing Escherichia coli for sterilization.

2. The sterilization method based on Cu-CNv heterogeneous Fenton-like catalyst according to claim 1, characterized in that: The magnetic stirrer is a multi-station magnetic stirrer.

3. The sterilization method based on Cu-CNv heterogeneous Fenton-like catalyst according to claim 1, characterized in that: In the step 1.2, the volume of deionized water containing NaBH4 is 40 mL, and the concentration of NaBH4 is 1 mol / L.

4. The sterilization method based on Cu-CNv heterogeneous Fenton-like catalyst according to claim 1, characterized in that: The mass fraction of CN in the CNv suspension is 0.8%.

5. The sterilization method based on Cu-CNv heterogeneous Fenton-like catalyst according to claim 1, characterized in that: In step 1.3, the concentration of the Cu(NO3)3·3H2O solution is 0.05 mol / L and the volume is 800 μL.

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