阅读说明：本技术 不同巯基化合物修饰的水分散性碲化银量子点的制备方法 (Preparation method of water-dispersible silver telluride quantum dots modified by different mercapto compounds ) 是由 刘书琳 王志刚 石学慧 于 2021-08-13 设计创作，主要内容包括：本发明提供了不同巯基化合物修饰的水分散性碲化银量子点的制备方法,由油溶性碲化银量子点与巯基配体通过配体交换法制备得到水分散性碲化银量子点,包括如下步骤：步骤1、将油溶性碲化银量子点溶于非极性有机溶剂中配制得到A溶液；步骤2、将巯基配体溶解在有机溶剂中配制得到B溶液；步骤3、将B溶液加入到A溶液中搅拌一定时间后进行离心,旋蒸除去有机溶剂；步骤4、将步骤3中得到的沉淀重新分散在缓冲溶液中,将水分散性量子点进行纯化以除去多余的巯基配体,最后收集上清液即得水分散性的量子点,本发明的不同巯基化合物修饰的水分散性碲化银量子点不仅能保持良好的胶体稳定性和高量子产率,而且保持了量子点良好的形貌和尺寸。(The invention provides a preparation method of water-dispersible silver telluride quantum dots modified by different mercapto compounds, which is prepared from oil-soluble silver telluride quantum dots and mercapto ligands by a ligand exchange method and comprises the following steps: step 1, dissolving oil-soluble silver telluride quantum dots in a nonpolar organic solvent to prepare a solution A; step 2, dissolving a sulfhydryl ligand in an organic solvent to prepare a solution B; step 3, adding the solution B into the solution A, stirring for a certain time, centrifuging, and removing the organic solvent by rotary evaporation; and 4, re-dispersing the precipitate obtained in the step 3 in a buffer solution, purifying the water-dispersible quantum dots to remove redundant sulfhydryl ligands, and finally collecting supernatant to obtain the water-dispersible quantum dots.)

1. The water-dispersible silver telluride quantum dot modified by different mercapto compounds is characterized in that: the water-dispersible silver telluride quantum dot is prepared from the oil-soluble silver telluride quantum dot and a sulfydryl ligand by a ligand exchange method.

2. The water-dispersible silver telluride quantum dot modified by different mercapto compounds as claimed in claim 1, wherein: the sulfhydryl ligand is one or more than two of reduced glutathione, DL-cysteine, beta-mercaptoethylamine, dihydrolipoic acid, dithiothreitol, HS-PEG350-OCH3, HS-PEG2000-COOH and DHLA-PEG350-OCH 3.

3. The water-dispersible silver telluride quantum dot modified by different mercapto compounds as claimed in claim 1, wherein: the quantum yield of the water-dispersible silver telluride quantum dot is 4-20%.

4. The preparation method of the water-dispersible silver telluride quantum dot modified by different mercapto compounds as claimed in claims 1-3, characterized in that: the method comprises the following steps:

step 1, dissolving oil-soluble silver telluride quantum dots in a nonpolar organic solvent to prepare a solution A;

step 2, dissolving a sulfhydryl ligand in an organic solvent to prepare a solution B;

step 3, adding the solution B into the solution A, stirring for a certain time, centrifuging, and removing the organic solvent by rotary evaporation;

and 4, re-dispersing the precipitate obtained in the step 3 in a buffer solution, purifying the water-dispersible quantum dots to remove redundant sulfydryl ligands, and finally collecting supernatant to obtain the water-dispersible quantum dots.

5. The preparation method of the water-dispersible silver telluride quantum dot modified by different mercapto compounds according to claim 4, wherein the preparation method comprises the following steps: the organic solvent is one of buffer solution or nonpolar organic solvent, the buffer solution is phosphate buffer solution, and the pH value of the phosphate buffer solution is more than or equal to 6.5.

6. The preparation method of the water-dispersible silver telluride quantum dot modified by different mercapto compounds according to claim 4, wherein the preparation method comprises the following steps: in the step 1, the concentration of the oil-soluble silver telluride quantum dots in the nonpolar organic solvent is 0.5-10 mg/mL, and the nonpolar organic solvent is any one of chloroform, dichloromethane, n-hexane and cyclohexane.

7. The preparation method of the water-dispersible silver telluride quantum dot modified by different mercapto compounds according to claim 4, wherein the preparation method comprises the following steps: in the step 2, the concentration of the B sulfhydryl ligand in the organic solvent is 5mg/mL-50 mg/mL.

8. The preparation method of the water-dispersible silver telluride quantum dot modified by different mercapto compounds according to claim 4, wherein the preparation method comprises the following steps: in the step 3, the stirring time of the solution A and the solution B is 2-60 minutes, and the volume ratio of the solution A to the solution B is 1: 10-20.

9. The preparation method of the water-dispersible silver telluride quantum dot modified by different mercapto compounds according to claim 1, characterized in that: in the step 4, the centrifugal rotation speed during purification is 6000-7500 r/min, the centrifugal time is 10-20 min, and the centrifugation is repeated for 3 times.

10. The application of the water-dispersible silver telluride quantum dot modified by different sulfhydryl compounds in any one of claims 1-4 in realizing noninvasive real-time fluorescence imaging of a living body.

Technical Field

The invention belongs to the fields of analytical chemistry, nano materials and surface colloid chemistry, and particularly relates to a preparation method of water-dispersible silver telluride quantum dots modified by different mercapto compounds.

Background

In-vivo imaging can simultaneously reflect physiological information at a temporal and spatial level; on the other hand, the same individual can be imaged for a long time, so as to track the physiological change process of the study object. At present, in vivo fluorescence imaging becomes an indispensable means for clinical applications such as disease diagnosis, surgical navigation, postoperative evaluation intervention and the like.

Compared with the traditional fluorescence imaging of the visible light and near infrared spectrum window 400-. In vivo NIR-II fluorescence imaging allows deeper tissue penetration and high definition fluorescence imaging when imaging in vivo due to attenuation of tissue autofluorescence and reduction of photon scattering. Among a plurality of NIR II fluorescent materials, the quantum dots have the advantages of adjustable emission wavelength, light drift resistance, wide absorption spectrum, narrow emission spectrum, easy surface functionalization and the like, and are ideal fluorescent imaging materials. To date, how to obtain NIR II quantum dots with high fluorescence intensity and good biocompatibility remains a challenge, mainly due to the inadequacies of surface functionalization strategies. This limits the ability of in vivo NIR-II imaging to enable non-invasive real-time imaging.

A number of ligands have been developed to prepare stable, highly water-soluble NIR-II quantum dots. Pegylation is a common strategy for quantum dot functionalization, since polyethylene glycol-modified nanoparticles have high biocompatibility, reducing non-specific interactions with serum proteins. However, the preparation of the pegylated quantum dot has the disadvantages of complicated operation and long time consumption, and the surface of the quantum dot is damaged, so that the fluorescence intensity is greatly reduced. Aiming at the problems, the water dispersibility of the NIR-II silver telluride quantum dots can be realized by a simple mechanical stirring method. In addition, due to the strong binding capacity of sulfydryl and silver, a series of polyethylene glycol sulfydryl ligands used in the process not only realize the water dispersibility and biocompatibility of the NIR-II silver telluride quantum dots, but also provide binding sites for the subsequent functionalization of the NIR-II silver telluride quantum dots due to the adjustable terminal group at the other end of the polyethylene glycol. Therefore, the water-dispersible NIR-II silver telluride quantum dot prepared by the method greatly shortens the preparation time, keeps the good fluorescence intensity and colloid stability of the NIR-II silver telluride quantum dot, can realize the noninvasive real-time fluorescence imaging of a living body, and clearly sees the leg artery blood vessels, the brain blood vessels and the tiny blood vessels on the abdomen of the mouse.

Disclosure of Invention

In view of the above, the invention aims to provide a preparation method of water-dispersible silver telluride quantum dots modified by different mercapto compounds, aiming at the problems of complex preparation of water-dispersible quantum dots in the phase transfer process, much reduced fluorescence intensity and the like, and the modification effect is not ideal.

In order to achieve the purpose, the technical scheme of the invention is realized as follows:

the water-dispersible silver telluride quantum dots modified by different mercapto compounds are prepared from oil-soluble silver telluride quantum dots and mercapto ligands by a ligand exchange method.

Preferably, the wavelength of the oil-soluble silver telluride quantum dot is in a near-infrared region II, and the wavelength is 1000-1700 nm.

Preferably, the sulfhydryl ligand is one or more than two of reduced Glutathione (GSH), DL-Cysteine (DL-Cysteine), beta-mercaptoethylamine (Cysteine), dihydrolipoic acid (DHLA), Dithiothreitol (DTT), HS-PEG350-OCH3, HS-PEG2000-COOH and DHLA-PEG350-OCH 3.

Preferably, the quantum yield of the water-dispersible silver telluride quantum dot is 4% -20%.

The second purpose of the invention is to provide a preparation method of the water-dispersible silver telluride quantum dot modified by different sulfhydryl compounds, which comprises the following steps:

step 1, dissolving oil-soluble silver telluride quantum dots in a nonpolar organic solvent to prepare a solution A;

step 2, dissolving a sulfhydryl ligand in an organic solvent to prepare a solution B;

step 3, adding the solution B into the solution A, stirring for a certain time, centrifuging, and removing the organic solvent by rotary evaporation;

and 4, re-dispersing the precipitate obtained in the step 3 in a buffer solution, purifying the water-dispersible quantum dots to remove redundant sulfydryl ligands, and finally collecting supernatant to obtain the water-dispersible quantum dots.

Preferably, in step 2, the organic solvent is one of a buffer solution and a non-polar organic solvent, the buffer solution is a phosphate buffer solution, and the pH value of the phosphate buffer solution is greater than or equal to 6.5.

Preferably, in the step 1, the concentration of the oil-soluble silver telluride quantum dot in the nonpolar organic solvent is 0.5mg/mL-10mg/mL, and the nonpolar organic solvent is any one of chloroform, dichloromethane, n-hexane and cyclohexane.

Preferably, in the step 2, the concentration of the B sulfhydryl ligand in the organic solvent is 5mg/mL-50 mg/mL.

Preferably, in the step 3, the stirring time of the solution a and the solution B is 2 to 60 minutes, and the volume ratio of the solution a to the solution B is 1: 10-20.

Preferably, in the step 4, the specification of the ultrafiltration tube used for purification is 30kDa, 50kDa and 100kDa, the centrifugation speed for purification is 6000-.

The third purpose of the invention is to provide the application of the water-dispersible silver telluride quantum dots modified by different sulfhydryl compounds in the noninvasive real-time fluorescence imaging of the living body.

The living body noninvasive real-time fluorescence imaging refers to fluorescence imaging of a living body (such as an experimental animal mouse) without living body dissection, and pharmacokinetic research, and the method is simple, convenient and feasible.

In the preparation process of the silver telluride quantum dot, an organic phase synthesis method is adopted, the surface of the quantum dot is hydrophobic and can only be dispersed in an organic solvent, and the quantum dot needs to be converted into water-dispersible in order to be biologically applicable. In the preparation process, only tri-n-butylphosphine (TBP) containing a P ligand is added, and experimental results show that in the process from an oil phase to a water phase, a surface ligand containing P, namely TBP, can fall off from the surface of an oily NIR-II silver telluride quantum dot under the stirring condition, a sulfhydryl ligand containing a hydrophilic group and the surface of the silver telluride quantum dot have strong coordination capacity, the TBP falls off, and the sulfhydryl surface ligand is immediately combined with the surface of the silver telluride quantum dot instead of the sulfhydryl ligand, so that the water dispersibility of the NIR-II silver telluride quantum dot is realized.

Compared with the prior art, the invention has the beneficial effects that:

(1) the prepared water-dispersible silver telluride quantum dot in the near-infrared II region is realized by a mechanical stirring method based on different sulfydryl ligands, and has high chemical stability and good water phase stability;

(2) according to the invention, the oily quantum dots are transferred to the buffer solution, and the near-infrared II-region silver telluride quantum dots dispersed in the buffer solution not only can keep good colloidal stability and high quantum yield, but also keep good appearance and size of the quantum dots, can be placed for 8 weeks at room temperature, and still can keep the original clear and transparent state;

(3) the method can greatly shorten the time for preparing the water-dispersible near-infrared region II silver telluride quantum dots, can well realize the functional modification of the water-dispersible near-infrared region II silver telluride quantum dots, is a very convenient and feasible method for realizing the phase transfer and the functional modification of the near-infrared region II silver telluride quantum dots, and provides a simpler, more convenient and more feasible operation for realizing the subsequent functionalization of the quantum dots.

Drawings

The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate an embodiment of the invention and, together with the description, serve to explain the invention and not to limit the invention. In the drawings:

FIG. 1 is a schematic diagram of an experimental embodiment and characterization of near-infrared region II silver telluride quantum dots;

FIG. 2 is a study of the mechanism of occurrence of the experiment;

FIG. 3 is the phase transfer results of different sulfhydryl ligands and the molecular structural formulas of different sulfhydryl ligands;

FIG. 4 shows the stability and light bleaching resistance of the HS-PEG350-OCH3, HS-PEG2000-COOH and DHLA-PEG350-OCH3 modified near-infrared II region silver telluride quantum dots;

FIG. 5 is mouse in vivo imaging of HS-PEG2000-COOH modified near-infrared region II silver telluride quantum dots;

FIG. 6 shows the mouse living body imaging of near-infrared II region silver telluride quantum dots modified by DHLA-PEG350-OCH3 and HS-PEG350-OCH3, and the pharmacokinetics and weight change of mice of near-infrared II region silver telluride quantum dots modified by HS-PEG350-OCH3, HS-PEG2000-COOH and DHLA-PEG350-OCH 3.

Detailed Description

Unless defined otherwise, technical terms used in the following examples have the same meanings as commonly understood by one of ordinary skill in the art to which the present invention belongs. The experimental reagents used in the following examples, unless otherwise specified, are all conventional biochemical reagents; the experimental methods are conventional methods unless otherwise specified.

The present invention will be described in detail with reference to the embodiments, but not limited thereto, with reference to the attached drawings.

The reagents used in the examples of the invention were as follows:

silver acetate: AR grade, shanghai mairei chemical technologies ltd;

tellurium powder: 99.999%, Shanghai Aladdin Biotechnology, Inc.;

trichloromethane: AR grade, jer certified industrial trade ltd, tianjin;

dihydrolipoic acid: DHLA, shanghai alatin biochemistry science and technology, ltd;

tributylphosphine: AR grade, camaute (tianjin) chemical technology ltd;

octadecylamine: AR grade, tianjin schinsensi opunktech limited;

1-octanethiol: 98%, Shanghai Aladdin Biotechnology, Inc.;

beta-mercaptoethylamine AR grade, Tianjin Medema Biotech ltd;

reduced glutathione: AR grade, tianjinmeidma biotechnology limited;

dithiothreitol: AR grade, tianjinmeidma biotechnology limited;

HS-PEG350-OCH3, Shanghai Aladdin Biotechnology, Inc.;

HS-PEG2000-OCH3 Shanghai Aladdin Biotechnology, Inc.

The experimental equipment used in the examples of the present invention is as follows:

SZCL-A type digital display intelligent temperature control magnetic stirrer (Zhengzhou great wall department, industrial and trade);

x-ray photoelectron spectroscopy (XPS, Kratos Analytical Ltd.)

High-sensitivity nanometer particle size analyzer (malvern);

high resolution transmission electron microscopy (FEI czech);

steady state/transient fluorescence spectrometer (Edinburgh Corp.);

small animal in vivo imager (Wuhan Grand-imaging Technology Co.).

Example 1: preparation method of water-dispersible NIR-II region silver telluride quantum dot

(1) Dissolving 77.6mg of tellurium powder in 9mL of TBP to prepare a tellurium precursor (with the concentration of 1 mol/L);

under the condition of introducing inert gas argon, taking 10mL of 1-octadecene, adding 520uL of octanethiol, stirring and heating to 70 ℃, after 30 minutes, adding 0.1g of silver acetate, heating to 150 ℃, then quickly injecting 250uL of tellurium precursor, immediately cooling to 120 ℃, preserving heat and growing for 30 minutes, cooling to room temperature, and obtaining Ag2Te quantum dots;

(2) dissolving oil-soluble silver telluride quantum dots in a nonpolar organic solvent to prepare a solution A, dissolving different sulfydryl ligands in a buffer solution or a nonpolar organic solvent to prepare a solution B, and then preparing a solution A by mixing the following components in a ratio of 1: 1, adding the solution B into the solution A, stirring and reacting for a certain time, removing the organic solvent by rotary evaporation after the reaction is finished, purifying by using an ultrafiltration tube to remove redundant ligand, and collecting supernatant to obtain the water-dispersible silver telluride quantum dot;

secondly, the structure and performance of the water dispersible quantum dot of the invention are explained in detail in the following with the attached drawings

Experimental example 1

FIG. 1 is a schematic diagram of an experimental embodiment and characterization of near-infrared region II silver telluride quantum dots; in FIG. 1, a is a schematic diagram of the implementation of this experimental embodiment; b is an absorption spectrum and an emission spectrum of the oily NIR-II silver telluride quantum dot, wherein the absorption peak is positioned at 923nm, and the emission peak is 1315 nm; c is a Transmission Electron Microscope (TEM) result of the oily NIR-II silver telluride quantum dot in the embodiment of the invention; d is a Transmission Electron Microscope (TEM) result of the water-dispersible NIR-II silver telluride quantum dot, and from the TEM and dynamic light scattering results, a phase transfer method for realizing the near-infrared II-region silver telluride quantum dot by using a mechanical stirring method based on different mercapto ligands is found, so that the size and the morphology of the quantum dot are hardly influenced; e is a polycrystal X-ray diffraction (XRD) result of the oily NIR-II silver telluride quantum dot disclosed by the embodiment of the invention, the XRD result shows that the prepared NIR-II silver telluride quantum dot has no obvious diffraction peak, the whole diffraction peak presents broadening, and the broadened diffraction peak is matched with the XRD diffraction peak (JCPDS 81-1820) of a monoclinic beta-Ag 2Te crystal; f is a plasma emission spectroscopy (ICP-OES) result of the oil-soluble NIR-II silver telluride quantum dot, and the result shows that the silver-tellurium ratio of the prepared NIR-II silver telluride quantum dot is 2: 1.

experimental example 2

Fig. 2 is a schematic diagram of a research on an experimental occurrence mechanism according to an embodiment of the present invention, where a in fig. 2 is an X-ray photoelectron spectroscopy characterization diagram of the oily NIR-II silver telluride quantum dot according to an embodiment of the present invention, and a result indicates that a surface ligand of a TBP containing P exists on the surface of the oily NIR-II silver telluride quantum dot; b is an X-ray photoelectron spectrum characterization diagram of the water-dispersible NIR-II silver telluride quantum dot provided by the embodiment of the invention, and the result shows that no surface ligand containing P exists on the surface of the water-dispersible NIR-II silver telluride quantum dot; the result surfaces of a and b are that in the process from an oil phase to a water phase, a surface ligand containing P, namely TBP, falls off from the surface of the oily NIR-II silver telluride quantum dot under the stirring condition and replaces the oily NIR-II silver telluride quantum dot with a sulfhydrylated surface ligand, so that the water dispersibility of the NIR-II silver telluride quantum dot is realized; c is a quantitative result of ICP-OES containing P in two different forms of the oil-phase NIR-II silver telluride quantum dot containing P content and the substituted clarified liquid containing P content, and the result is that the substitution amount of the ligand containing P on the surface of the oily NIR-II silver telluride quantum dot is 98.92%, which shows that the ligand containing P on the surface of the oily NIR-II silver telluride quantum dot is largely substituted, so that the ligand containing sulfydryl is added, and the water dispersibility of the NIR-II silver telluride quantum dot is realized; e is the structural formula of the lipoic acid used in the embodiment of the invention, and in order to verify whether the phase transfer of the NIR-II silver telluride quantum dots based on the method can be realized only by ligand molecules containing free sulfydryl, lipoic acid molecules without free sulfydryl are selected; and f is a phase transfer result of the oily NIR-II silver telluride quantum dot by using the lipoic acid, and the result shows that the lipoic acid cannot smoothly realize the phase transfer of the oily NIR-II silver telluride quantum dot, so that the fact that the phase transfer of the NIR-II silver telluride quantum dot based on the method can be realized only by ligand molecules containing free sulfydryl is verified.

Experimental example 3

FIG. 3 is the phase transfer results of different sulfhydryl ligands and the molecular structural formulas of different sulfhydryl ligands; fig. 3 a is an experimental schematic diagram of the present invention, and the experimental result of fig. 2 shows that the surface of the oily NIR-II silver telluride quantum dot has a P-containing ligand, i.e., TBP added in the experimental process, when the oily NIR-II silver telluride quantum dot is dispersed in chloroform, a free thiol-containing ligand dissolved in a buffer solution is added, and under the condition of mechanical stirring, the P-containing ligand can fall off from the surface of the quantum dot, and the free thiol-containing ligand is combined with the quantum dot, thereby realizing the phase transfer of the oily NIR-II silver telluride quantum dot; and b is the phase transfer result of NIR-II silver telluride quantum dots and the structural formulas of different sulfydryl ligand molecules realized by different sulfydryl ligand molecules based on a mechanical stirring method.

Experimental example 4:

FIG. 4 shows the stability and light bleaching resistance of the near-infrared II-region silver telluride quantum dots modified by HS-PEG350-OCH3, HS-PEG2000-COOH and DHLA-PEG350-OCH3, in fig. 4, a, b and c are DLS test results of different time after the phase transfer of the oily NIR-II silver telluride quantum dot based on DHLA-PEG350-OCH3, HS-PEG350-OCH3 and HS-PEG2000-COOH used in the embodiment of the present invention, respectively, and from the particle size, Zeta potential and the dispersion degree of the hydrated particle size, i.e. PDI value, we can see that after 8 weeks, the water-dispersible NIR-II silver telluride quantum dots prepared by realizing the phase transfer of the oily NIR-II silver telluride quantum dots on the basis of DHLA-PEG350-OCH3, HS-PEG350-OCH3 and HS-PEG2000-COOH are stable in water dispersibility and can be stored for a long time for later use; in fig. 4, d and e are light-bleaching resistance experiments of the water-dispersible NIR-II silver telluride quantum dots prepared by implementing phase transfer of oily NIR-II silver telluride quantum dots based on DHLA-PEG350-OCH3, HS-PEG350-OCH3, and HS-PEG2000-COOH, which are described in the embodiments of the present invention, and the results show that after 808 laser is continuously irradiated for 30 minutes, the fluorescence intensity of the NIR-II silver telluride quantum dots modified by DHLA-PEG350-OCH3, HS-PEG350-OCH3, and HS-PEG2000-COOH is hardly reduced, but the organic small molecule dye indocyanine green (ICG) is reduced by more than 80%.

Experimental example 5:

FIG. 5 shows the imaging results of a mouse with the NIR-II silver telluride quantum dots modified by HS-PEG2000-COOH, wherein a is the imaging results of the abdomen of the mouse, and the blood vessels of the abdomen of the mouse can be seen from the results; b is mouse leg blood vessel imaging according to the embodiment of the invention; c is the mouse brain blood vessel imaging of the embodiment of the invention; e is the mouse leg blood vessel imaging at different times in the embodiment of the invention, so that the venous blood vessels and the arterial blood vessels of the mouse can be clearly seen along with the time, and the living body imaging result of the mouse shows that the water-dispersible NIR-II silver telluride quantum dots prepared by the stirring method of HS-PEG2000-COOH still have high-brightness fluorescence property, and the circulation of the water-dispersible NIR-II silver telluride quantum dots in the mouse can be maintained due to the longer chain of the polyethylene glycol.

Experimental example 6:

FIG. 6 shows the mouse living body imaging of near-infrared II region silver telluride quantum dots modified by DHLA-PEG350-OCH3 and HS-PEG350-OCH3, and the pharmacokinetics and weight change of mice of near-infrared II region silver telluride quantum dots modified by HS-PEG350-OCH3, HS-PEG2000-COOH and DHLA-PEG350-OCH 3; in fig. 6, a, b, and c are imaging results of abdominal blood vessels, leg blood vessels, and brain blood vessels of a mouse with NIR-II silver telluride quantum dots modified by DHLA-PEG350-OCH3 according to an embodiment of the present invention, respectively, and the results show that the water-dispersible NIR-II silver telluride quantum dots prepared by the stirring method of DHLA-PEG350-OCH3 still have a fluorescent property with high brightness, and the circulation of the water-dispersible NIR-II silver telluride quantum dots in the mouse can be maintained due to the long chain of the polyethylene glycol; d is a mouse imaging result of the HS-PEG350-OCH3 modified NIR-II silver telluride quantum dot, and the result shows that almost all the NIR-II silver telluride quantum dots are gathered at the liver part of the mouse, which is caused by the short chain of the polyethylene glycol, so that the HS-PEG350-OCH3 modified NIR-II silver telluride quantum dot can not circulate in the mouse body; e is the pharmacokinetics in vivo of the mice of the NIR-II silver telluride quantum dots modified by DHLA-PEG350-OCH3, HS-PEG350-OCH3 and HS-PEG2000-COOH, and the results show that the water-dispersible NIR-II silver telluride quantum dots prepared by the phase transfer of the near infrared II region silver telluride quantum dots based on the mechanical stirring method of different sulfhydryl ligands are rapidly metabolized in the mice; f is the weight change of the mouse after NIR-II silver telluride quantum dots modified by DHLA-PEG350-OCH3, HS-PEG350-OCH3 and HS-PEG2000-COOH are injected into the mouse through tail veins; the results show that the weight of the mouse is stable and the change is small, and that the in vivo toxicity of the water-dispersible NIR-II silver telluride quantum dot prepared by the phase transfer of the near-infrared II-region silver telluride quantum dot based on the mechanical stirring method of different sulfhydryl ligands is small.

The above description is only for the purpose of illustrating the preferred embodiments of the present invention and is not to be construed as limiting the invention, and any modifications, equivalents, improvements and the like that fall within the spirit and principle of the present invention are intended to be included therein.