阅读说明：本技术 一种特异性抗葡萄球菌的氮掺杂碳量子点及其制备方法 (Specific anti-staphylococcus nitrogen-doped carbon quantum dot and preparation method thereof ) 是由 赵成飞 阮志鹏 潘凌鸿 于 2021-01-30 设计创作，主要内容包括：本发明提供的是一种特异性抗葡萄球菌的氮掺杂碳量子点及其制备方法,以葡萄糖和二乙烯三胺为反应底物通过“一步法”合成具有特异性抗葡萄球菌的氮掺杂碳量子点。本发明制备工艺简单,反应底物廉价,合成反应容易,且所得氮掺杂碳量子点具有特异性抗葡萄球菌活性,可以用于葡萄球菌(包括金黄色葡萄球菌、表皮葡萄球菌和耐甲氧西林金黄色葡萄球菌(MRSA))感染创面的治疗。(The invention provides a specific staphylococcus-resistant nitrogen-doped carbon quantum dot and a preparation method thereof, wherein the specific staphylococcus-resistant nitrogen-doped carbon quantum dot is synthesized by a one-step method by taking glucose and diethylenetriamine as reaction substrates. The preparation method is simple in preparation process, cheap in reaction substrate and easy in synthesis reaction, and the obtained nitrogen-doped carbon quantum dots have specific anti-staphylococcus activity and can be used for treating the infection wound surfaces of staphylococcus (including staphylococcus aureus, staphylococcus epidermidis and methicillin-resistant staphylococcus aureus (MRSA)).)

1. The utility model provides a nitrogen-doped carbon quantum dot of anti staphylococcus of specificity which characterized in that: the glucose-diethylenetriamine composite material comprises glucose and diethylenetriamine, wherein the proportion of the glucose to the diethylenetriamine is as follows: 1 g: 1 mL.

2. A preparation method of a specific anti-staphylococcus nitrogen-doped carbon quantum dot is characterized by comprising the following steps: glucose and diethylenetriamine are used as reaction substrates to synthesize the nitrogen-doped carbon quantum dot with specificity to resist staphylococcus by a one-step method.

3. The method for preparing the specific anti-staphylococcus nitrogen-doped carbon quantum dot according to claim 2, wherein the method comprises the following steps: the method specifically comprises the following steps:

(1) accurately weighing 2 g of glucose powder, placing the glucose powder in a 50 mL round-bottom flask, and heating for 20 min at the temperature of 150-;

(2) after the glucose powder is melted, adding 2 mL of diethylenetriamine, and continuing to magnetically stir and react for 20 min at the temperature of 150-;

(3) cooling the black solid product to room temperature, and adding 2 mL of deionized water to dissolve the black solid product to obtain a product solution;

(4) then, adjusting the pH value of the product solution to 7 by using 10 mmol/L hydrochloric acid, diluting the product solution to 4 mL by using deionized water, and filtering the product solution by using a 0.22 mu m filter membrane to obtain primary filtrate;

(5) centrifuging the primary filtrate in 3000 MWCO ultrafiltration centrifuge tube at 7500 rpm for 10-30 min, discarding filtrate, adding 2 mL deionized water, mixing, centrifuging at 7500 rpm for 10-30 min, discarding filtrate, repeating centrifuging operation for 3 times, and collecting upper layer liquid;

(6) and after centrifugal treatment, taking the upper layer liquid for freeze drying for 24 hours to obtain the nitrogen-doped carbon quantum dot powder.

Technical Field

The invention belongs to the technical field of carbon nano material antibiosis, and particularly relates to a preparation method of a specific staphylococcus-resistant nitrogen-doped carbon quantum dot.

Background

The carbon quantum dot is a novel carbon nano material with the particle size less than 10 nanometers, and is mainly synthesized by taking an organic matter as a precursor substrate through a 'bottom-up' strategy. Among many carbon nanomaterials, the carbon quantum dots belonging to the zero-dimensional carbon nanomaterial have unique morphology, size, surface functional groups and physicochemical characteristics, other elements (such as nitrogen, oxygen and sulfur) are easily doped in the preparation process, and the carbon quantum dots with different properties can be conveniently designed and prepared according to requirements. Compared with other carbon nanomaterials (such as graphene) and semiconductor quantum dots (such as CdSe quantum dots), the carbon quantum dots have obvious advantages in the aspects of heteroelement doping, surface modification and water solubility, generally have better biocompatibility, can interact with biological systems, and exhibit specific biological functions, so that the application of the carbon quantum dots in the field of biomedicine gradually receives wide attention.

In the face of the dilemma of research and development of novel antibacterial drugs, domestic and foreign scholars find that carbon quantum dots prepared under specific conditions by taking specific organic matters as reaction substrates have certain antibacterial activity, and the carbon quantum dots can have the specific antibacterial activity by changing doped elements and the content thereof, open a new research direction for research and development of novel antibacterial drugs, and provide more choices for solving the problem that the drug resistance of bacteria is more and more serious.

Disclosure of Invention

The invention aims to provide a preparation method of a specific anti-staphylococcus nitrogen-doped carbon quantum dot, which has the advantages of simple preparation process, cheap reaction substrate and easy synthesis reaction, and the obtained nitrogen-doped carbon quantum dot has specific anti-staphylococcus activity and can be used for treating the infection wound surface of staphylococcus (including staphylococcus aureus, staphylococcus epidermidis and methicillin-resistant staphylococcus aureus (MRSA)).

In order to achieve the purpose, the invention adopts the following technical scheme:

a preparation method of a specific anti-staphylococcus nitrogen-doped carbon quantum dot comprises the following steps: glucose and diethylenetriamine are used as reaction substrates to synthesize the nitrogen-doped carbon quantum dot with specificity to resist staphylococcus by a one-step method.

The method specifically comprises the following steps:

(1) accurately weighing 2 g of glucose powder, placing the glucose powder in a 50 mL round-bottom flask, and heating for 20 min at the temperature of 150-;

(2) after the glucose powder is melted, adding 2 mL of diethylenetriamine, and continuing to magnetically stir and react for 20 min at the temperature of 150-;

(3) cooling the black solid product to room temperature, and adding 2 mL of deionized water to dissolve the black solid product to obtain a product solution;

(4) then, adjusting the pH value of the product solution to 7 by using 10 mmol/L hydrochloric acid, diluting the product solution to 4 mL by using deionized water, and filtering the product solution by using a 0.22 mu m filter membrane to obtain primary filtrate;

(5) centrifuging the primary filtrate in an ultrafiltration centrifuge tube (3000 MWCO) at 7500 rpm for 10-30 min, discarding the filtrate, adding 2 mL deionized water, mixing, centrifuging at 7500 rpm for 10-30 min, discarding the filtrate, repeating the centrifuging operation for 3 times, and collecting the upper layer liquid;

(6) and after centrifugal treatment, taking the upper layer liquid for freeze drying for 24 hours to obtain the nitrogen-doped carbon quantum dot powder.

Compared with the prior art, the invention has the following advantages and effects:

(1) according to the invention, the nitrogen-doped carbon quantum dots with the particle size of 2-5 nm are successfully prepared by a one-step method by using glucose and diethylenetriamine as reaction substrates, the synthesis process is simple, and the preparation cost is low;

(2) the nitrogen-doped carbon quantum dots have selective antibacterial activity on staphylococcus (including staphylococcus aureus (ATCC 6538), staphylococcus aureus (ATCC 43300), staphylococcus epidermidis and MRSA), and can generate specific antibacterial action on the staphylococcus.

Drawings

FIG. 1 is a Transmission Electron Microscope (TEM) image of nitrogen-doped carbon quantum dots obtained in example 1 of the present invention.

FIG. 2 is an Atomic Force Microscope (AFM) image of nitrogen-doped carbon quantum dots obtained in example 1 of the present invention.

Fig. 3 is a height diagram of the nitrogen-doped carbon quantum dots obtained in example 1 of the present invention in an AFM image.

FIG. 4 is a Fourier Transform Infrared (FTIR) spectrum of nitrogen-doped carbon quantum dots obtained in example 1 of the present invention.

FIG. 5 shows the bacteriostatic effect of the nitrogen-doped carbon quantum dots on Staphylococcus aureus (ATCC 6538) according to the present invention.

FIG. 6 shows the bacteriostatic effect of the nitrogen-doped carbon quantum dots on Staphylococcus aureus (ATCC 3300) according to the present invention.

FIG. 7 shows the bacteriostatic effect of the nitrogen-doped carbon quantum dots on Staphylococcus epidermidis.

FIG. 8 shows the bacteriostatic effect of the nitrogen-doped carbon quantum dots on methicillin-resistant Staphylococcus aureus (MRSA) according to the invention.

FIG. 9 TEM image of Staphylococcus aureus in normal medium.

FIG. 10 is a TEM image of Staphylococcus aureus in the culture medium containing nitrogen-doped carbon quantum dots obtained in example 1 of the present invention.

FIG. 11 TEM image of MRSA in normal medium.

FIG. 12 TEM image of MRSA in a medium containing nitrogen-doped carbon quantum dots obtained in example 1 of the present invention.

Detailed Description

In order to make the content of the present invention more comprehensible, the technical solutions of the present invention are further described below with reference to specific embodiments, but the present invention is not limited thereto.

Example 1

(1) Accurately weighing 2 g of glucose powder, placing the glucose powder in a 50 mL round-bottom flask, and heating for 20 min at 150 ℃ for melting to obtain glucose in a molten state;

(2) after the glucose powder is melted, adding 2 mL of diethylenetriamine, and continuing to magnetically stir and react for 20 min at the temperature of 150 ℃ to obtain a black solid product;

(3) cooling the black solid product to room temperature, and adding 2 mL of deionized water to dissolve the black solid product to obtain a product solution;

(4) then, adjusting the pH value of the product solution to 7 by using 10 mmol/L hydrochloric acid, diluting the product solution to 4 mL by using deionized water, and filtering the product solution by using a 0.22 mu m filter membrane to obtain primary filtrate;

(5) centrifuging the primary filtrate in an ultrafiltration centrifuge tube (3000 MWCO) at 7500 rpm for 30 min, discarding the filtrate, adding 2 mL deionized water, mixing, centrifuging at 7500 rpm for 30 min, discarding the filtrate, repeating the centrifuging operation for 3 times, and collecting the upper layer liquid;

(6) after the centrifugal treatment, the upper layer liquid was taken out and freeze-dried for 24 h to obtain nitrogen-doped carbon quantum dot powder, which was recorded as M1.

Fig. 1, fig. 2 and fig. 3 are a TEM image, an AFM image and a height sectional view of the nitrogen-doped carbon quantum dot in the AFM image, respectively, and it can be seen from the images that the nitrogen-doped carbon quantum dot obtained by the present invention has better dispersibility and uniformity and a particle size of about 5 nm. FIG. 4 is an FTIR chart of nitrogen-doped carbon quantum dots, from which it can be seen that the surface of the nitrogen-doped carbon quantum dots obtained by the present invention contains amino groups (-NH-or-NH-)₂) Carboxyl (-COOH) and hydroxyl (-OH).

Example 2

(1) Accurately weighing 2 g of glucose powder, placing the glucose powder in a 50 mL round-bottom flask, and heating for 20 min at 155 ℃ for melting to obtain glucose in a molten state;

(2) after the glucose powder is melted, adding 2 mL of diethylenetriamine, and continuing to magnetically stir and react for 20 min at the temperature of 155 ℃ to obtain a black solid product;

(3) cooling the black solid product to room temperature, and adding 2 mL of deionized water to dissolve the black solid product to obtain a product solution;

(4) then, adjusting the pH value of the product solution to 7 by using 10 mmol/L hydrochloric acid, diluting the product solution to 4 mL by using deionized water, and filtering the product solution by using a 0.22 mu m filter membrane to obtain primary filtrate;

(5) centrifuging the primary filtrate in an ultrafiltration centrifuge tube (3000 MWCO) at 7500 rpm for 30 min, discarding the filtrate, adding 2 mL deionized water, mixing, centrifuging at 7500 rpm for 30 min, discarding the filtrate, repeating the centrifuging operation for 3 times, and collecting the upper layer liquid;

(6) after the centrifugal treatment, the upper layer liquid was taken out and freeze-dried for 24 h to obtain nitrogen-doped carbon quantum dot powder, which was recorded as M2.

Example 3

(1) Accurately weighing 2 g of glucose powder, placing the glucose powder in a 50 mL round-bottom flask, and heating for 20 min at 160 ℃ for melting to obtain glucose in a molten state;

(2) after the glucose powder is melted, adding 2 mL of diethylenetriamine, and continuing to magnetically stir and react for 20 min at the temperature of 160 ℃ to obtain a black solid product;

(3) cooling the black solid product to room temperature, and adding 2 mL of deionized water to dissolve the black solid product to obtain a product solution;

(4) then, adjusting the pH value of the product solution to 7 by using 10 mmol/L hydrochloric acid, diluting the product solution to 4 mL by using deionized water, and filtering the product solution by using a 0.22 mu m filter membrane to obtain primary filtrate;

(5) centrifuging the primary filtrate in an ultrafiltration centrifuge tube (3000 MWCO) at 7500 rpm for 30 min, discarding the filtrate, adding 2 mL deionized water, mixing, centrifuging at 7500 rpm for 30 min, discarding the filtrate, repeating the centrifuging operation for 3 times, and collecting the upper layer liquid;

(6) after the centrifugal treatment, the upper layer liquid was taken out and freeze-dried for 24 h to obtain nitrogen-doped carbon quantum dot powder, which was recorded as M3.

Application examples

Bacterial culture and bacterial liquid preparation method

All test bacteria are firstly inoculated on a blood agar plate by a plate marking method and cultured in a biochemical incubator (35 ℃) to obtain a single colony, the single colony is picked by an inoculating loop and inoculated in sterilized normal saline (0.9 percent sodium chloride solution) to obtain a bacterial suspension, and the OD600 value of the bacterial suspension is measured and adjusted to be 0.1 by an ultraviolet visible spectrophotometer to obtain 1.5 multiplied by 10⁸CFU/mL of bacterial suspension.

Paper sheet diffusion experiment method

Using sterile medical cotton swab to make concentration be 1.5X 10⁸CFU/mL bacterial suspension is evenly smeared on MH agar culture medium (phi =90 mm), and then drug sensitive paper sheets (phi =6 mm) containing test nitrogen-doped carbon quantum dots are placed, wherein the distance between the centers of each drug sensitive paper sheet is at least 24 mm. After incubation for 18 hours in a biochemical incubator (35 ℃), photographs were taken and the diameter of the zone of inhibition around each drug sensitive paper piece was measured with a vernier caliper.

Fig. 5, 6, 7 and 8 are paper diffusion experiments of the nitrogen-doped carbon quantum dots obtained in examples 1-3 on staphylococcus aureus (ATCC 6538), staphylococcus aureus (ATCC 3300), staphylococcus epidermidis and MRSA, respectively, and it can be seen from the drawings that the nitrogen-doped carbon quantum dots obtained in the present invention have good bacteriostatic effects on the above four bacteria, form significant bacteriostatic rings on MH agar plates, and have diameters larger than 15 mm. FIGS. 9 and 11 show Staphylococcus aureus and MRSA cultured under normal conditions, and it can be seen that both bacteria have intact cell structures. FIGS. 10 and 12 show Staphylococcus aureus and MRSA incubated in the culture medium containing the nitrogen-doped carbon quantum dots, from which it can be clearly seen that the cell walls and cell membranes of the two bacteria are obviously broken after being acted by the nitrogen-doped carbon quantum dots, the thallus is disintegrated, the intracellular substances are leaked, and the thallus cells lose integrity. The result proves that the obtained nitrogen-doped carbon quantum dots have good antibacterial effect on staphylococcus.

The above description is only a preferred embodiment of the present invention, and all equivalent changes and modifications made in accordance with the claims of the present invention should be covered by the present invention.