Glycerin modified cerium oxide nanoparticles, preparation method and anti-oxidation application of glycerol modified cerium oxide nanoparticles

Abstract

The invention provides a preparation method of glycerol-modified cerium oxide nanoparticles and an anti-oxidation application of the glycerol-modified cerium oxide nanoparticles. The preparation method of the glycerol-modified cerium oxide nanoparticles comprises the following steps: mixing soluble cerium salt, glycerol and water, adding a precipitator, and carrying out precipitation reaction and dehydration reaction to prepare the glycerol-modified cerium oxide nanoparticles. The glycerol modified cerium oxide is prepared from the raw materials containing cerium salt and glycerol, the reaction system is simple, the reaction condition is mild, the reaction can be carried out under the conditions of room temperature and normal pressure, and the reaction time is short.

Description

Technical Field

[0001] The invention relates to the technical field of nano material preparation, and in particular to glycerol-modified cerium oxide nanoparticles, a preparation method and an antioxidant application thereof. Background Art

[0002] Cerium oxide (CeO2) nanomaterials have important application value in the field of biological antioxidants because of their ability to eliminate a variety of reactive oxygen species and good biosafety. For example, CeO2 nanomaterials can eliminate excessive superoxide anion radicals, hydroxyl radicals, hydrogen peroxide, etc. in the body, and have the effect of treating chronic inflammation, ischemic stroke, retinal degeneration caused by ultraviolet radiation, neurological diseases and other diseases related to reactive oxygen species. In addition, CeO2 nanomaterials can also be used in other biomedical fields such as immune detection and drug delivery.

[0003] The activity and performance of CeO2 nanoparticles depend on the content of oxygen vacancies. In order to change the degree of oxygen vacancies on the CeO2 surface, traditional technologies use methods such as reducing the size of nanoparticles and modifying their morphology. The properties of nanoparticles also depend on different parameters, such as the synthesis procedure, solvent, or reaction temperature or time. The synthesis strategy of CeO2 nanoparticles is mainly based on physical and chemical methods.

[0004] Traditional chemical and physical methods for synthesizing CeO2 nanoparticles require high energy consumption to maintain temperature and pressure during the synthesis process, use of hazardous reagents and solvents that produce toxic byproducts to human health and the environment, long reaction times, or many steps during the synthesis process. In addition, some physical methods require high vacuum and expensive equipment. However, these synthetic routes are not suitable when the nanoparticles are used in biomedical applications, so a simpler and milder method is needed to synthesize CeO2 nanoparticles. Summary of the invention

[0005] In view of the problems existing in the prior art, a method for preparing glycerol-modified cerium oxide nanoparticles is provided.

[0006] In some embodiments, a method for preparing glycerol-modified cerium oxide nanoparticles is provided, comprising the steps of mixing a soluble cerium salt, glycerol and water, adding a precipitant, performing a precipitation reaction, and performing a dehydration reaction to prepare glycerol-modified cerium oxide nanoparticles.

[0007] In some embodiments, the preparation method meets one or more of the following characteristics:

[0008] The soluble cerium salt is cerium nitrate or cerium nitrate hexahydrate;

[0009] In the step of mixing the soluble cerium salt, glycerol and water, the mass of glycerol relative to the sum of the mass of the soluble cerium salt and glycerol is 33.3% to 75% based on the amount of feed;

[0010] The step of mixing the soluble cerium salt, glycerol and water comprises: mixing a first aqueous solution containing the soluble cerium salt and a second aqueous solution containing glycerol.

[0011] In some embodiments, in the step of mixing the soluble cerium salt, glycerol and water, the mass of glycerol relative to the sum of the masses of the soluble cerium salt and glycerol is 50% to 75% based on the feed amount.

[0012] In some embodiments, the preparation method meets one or more of the following characteristics:

[0013] In the step of mixing the soluble cerium salt, glycerol and water and adding the precipitant, the volume mass ratio of the precipitant to the soluble cerium salt is (1-1.5) mL / g based on the amount of feed;

[0014] The precipitant is in liquid form, and is added dropwise;

[0015] The precipitant is added at a rate of 0.3 mL / min to 0.5 mL / min;

[0016] The precipitant is aqueous ammonia;

[0017] The mass concentration of the precipitant is 25% to 28%.

[0018] In some embodiments, the preparation method meets one or more of the following characteristics:

[0019] In the step of performing the precipitation reaction, the reaction temperature is 5°C to 30°C;

[0020] In the step of performing the precipitation reaction, the reaction time is 2h~6h.

[0021] In some embodiments, after the precipitation reaction is completed, the following steps are further included: solid-liquid separation, solid phase collection, water washing, and dehydration reaction.

[0022] In some embodiments, the dehydration reaction comprises drying at -20°C to 50°C.

[0023] In some embodiments, a glycerol-modified cerium oxide nanoparticle is provided, comprising cerium oxide and glycerol modified on the cerium oxide.

[0024] In some embodiments, the glycerol-modified cerium oxide nanoparticles satisfy at least one of the following conditions:

[0025] The potential is 35.35 mV~35.57 mV;

[0026] The DPPH clearance rate was 95.8%~96.8%;

[0027] The hydrated particle size is 8.19 nm~32.44 nm;

[0028] D hkl is 2.66nm~4.57nm; among them, D hkl is the crystallite size;

[0029] The glycerol-modified cerium oxide nanoparticles are prepared according to the preparation method of the glycerol-modified cerium oxide nanoparticles.

[0030] In some embodiments, the use of the glycerol-modified cerium oxide nanoparticles in eliminating free radicals is provided;

[0031] Wherein, the free radicals include one or more of superoxide anion free radicals, hydroxyl free radicals, hydrogen peroxide and nitrogen free radicals;

[0032] Optionally, the application is not a method for diagnosing or treating a disease.

[0033] In some embodiments, a cosmetic, a medicine or a detection reagent is provided, comprising the glycerol-modified cerium oxide nanoparticles.

[0034] Most of the existing methods for preparing synthetic cerium oxide have complex reaction systems and require harsh conditions such as high temperature and high pressure.

[0035] The preparation method provided above in the present application, by using raw materials containing cerium salt and glycerol to prepare glycerol-modified cerium oxide, has a simple reaction system, mild reaction conditions, can be reacted at room temperature and normal pressure, and has a short reaction time. The modified glycerol used is cheap and easy to obtain. The prepared glycerol-modified cerium oxide has a small particle size and has a high free radical scavenging performance. BRIEF DESCRIPTION OF THE DRAWINGS

[0036] In order to more clearly illustrate the technical solutions in the implementation methods and examples of the present application and to more completely understand the present application and its beneficial effects, the following is a brief introduction to the drawings required for use in the description of the implementation methods or examples. Obviously, the drawings described below are only some embodiments of the present application, and those skilled in the art can obtain other drawings based on these drawings without creative work.

[0037] Figure 1 This is a flow chart of the preparation process of glycerol-modified cerium oxide nanoparticles in one embodiment of the present application;

[0038] Figure 2 The XRD patterns of the glycerol-modified cerium oxide obtained in Examples 1-5, wherein (a) is the XRD pattern of unmodified CeO2, (b) is the XRD pattern of the glycerol-modified cerium oxide obtained in Example 1, (c) is the XRD pattern of the glycerol-modified cerium oxide obtained in Example 2, (d) is the XRD pattern of the glycerol-modified cerium oxide obtained in Example 3, (e) is the XRD pattern of the glycerol-modified cerium oxide obtained in Example 4, and (f) is the XRD pattern of the glycerol-modified cerium oxide obtained in Example 5;

[0039] Figure 3 Figures are diagrams of powdered products of glycerol-modified cerium oxide obtained in Examples 1-5, wherein a is a diagram of a powdered product of unmodified cerium oxide, b is a diagram of a powdered product of glycerol-modified cerium oxide obtained in Example 1, c is a diagram of a powdered product of glycerol-modified cerium oxide obtained in Example 2, d is a diagram of a powdered product of glycerol-modified cerium oxide obtained in Example 3, e is a diagram of a powdered product of glycerol-modified cerium oxide obtained in Example 4, and f is a diagram of a powdered product of glycerol-modified cerium oxide obtained in Example 5;

[0040] Figure 4 is the infrared spectrum of glycerol-modified cerium oxide obtained in Example 4, wherein Wavemumber is the wave number and Transmittance is the transmittance;

[0041] Figure 5 The graphs are the results of the hydrated particle size of glycerol-modified cerium oxide obtained in Examples 1-5, wherein a is the result of the hydrated particle size of unmodified cerium oxide, b is the result of the hydrated particle size of glycerol-modified cerium oxide obtained in Example 1, c is the result of the hydrated particle size of glycerol-modified cerium oxide obtained in Example 2, d is the result of the hydrated particle size of glycerol-modified cerium oxide obtained in Example 3, e is the result of the hydrated particle size of glycerol-modified cerium oxide obtained in Example 4, and f is the result of the hydrated particle size of glycerol-modified cerium oxide obtained in Example 5, Diamter is diameter, and Percentage is percentage;

[0042] Figure 6TEM images and particle size distribution diagrams of unmodified cerium oxide and glycerol-modified cerium oxide of Example 4, wherein a is a transmission electron microscope image of unmodified cerium oxide, with a scale of 50 nm; b is a transmission electron microscope image of unmodified cerium oxide, with a scale of 20 nm; c is a particle size distribution diagram obtained by statistically analyzing the particle sizes of 50 particles in transmission electron microscope image b using Image J analysis software; d is a transmission electron microscope image of glycerol-modified cerium oxide of Example 4, with a scale of 50 nm; e is a transmission electron microscope image of glycerol-modified cerium oxide of Example 4, with a scale of 20 nm; f is a particle size distribution diagram obtained by statistically analyzing the particle sizes of 50 particles in transmission electron microscope image e using Image J analysis software; Diamter is diameter, and Fequency is frequency;

[0043] Figure 7 0.5 wt% glycerol-modified cerium oxide dispersion state diagram of Examples 1-5, wherein a is the dispersion state of 0.5 wt% unmodified cerium oxide, b is the dispersion state of 0.5 wt% glycerol-modified cerium oxide obtained in Example 1, c is the dispersion state of 0.5 wt% glycerol-modified cerium oxide obtained in Example 2, d is the dispersion state of 0.5 wt% glycerol-modified cerium oxide obtained in Example 3, e is the dispersion state of 0.5 wt% glycerol-modified cerium oxide obtained in Example 4, and f is the dispersion state of 0.5 wt% glycerol-modified cerium oxide obtained in Example 5;

[0044] Figure 8 The results of the scavenging effect of glycerol-modified cerium oxide on DPPH free radicals in Examples 1-5;

[0045] Fig. 9 The results of scavenging effects of glycerol-modified cerium oxide obtained in Example 1 and the products of Comparative Examples 1-4 on DPPH free radicals;

[0046] Fig.10 This is a diagram of the synthesis using sodium hydroxide as a precipitant in Comparative Example 5, wherein A is a picture of all raw materials mixed before the reaction, and B is a picture of the product after the reaction. DETAILED DESCRIPTION

[0047] In order to facilitate the understanding of the present invention, the present invention will be described more fully below with reference to the relevant drawings. The preferred embodiments of the present invention are given in the drawings. However, the present invention can be implemented in many different forms and is not limited to the embodiments described herein. On the contrary, the purpose of providing these embodiments is to make the understanding of the disclosure of the present invention more thorough and comprehensive.

[0048] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as those commonly understood by those skilled in the art to which the present invention belongs. The terms used herein in the specification of the present invention are only for the purpose of describing specific embodiments and are not intended to limit the present invention. The term "and / or" used herein includes any and all combinations of one or more of the related listed items.

[0049] the term

[0050] Unless otherwise specified or incompatible herewith, the terms and phrases used herein shall have the following meanings:

[0051] The terms "and / or", "or / and", and "and / or" used in this application include any one of two or more related listed items, and also include any and all combinations of the related listed items, wherein the any and all combinations include any combination of two related listed items, any more related listed items, or all related listed items.

[0052] In the present application, "plurality", "multiple", "multiple times", "multiples", etc., unless otherwise specified, refer to a number greater than 2 or equal to 2. For example, "one or more" means one or greater than or equal to two.

[0053] The terms "combination thereof", "any combination thereof", "any combination thereof" and the like used in this application include all suitable combinations of any two or more of the listed items.

[0054] In this application, the "suitable" mentioned in "suitable combination", "suitable method", "any suitable method", etc. is based on the ability to implement the technical solution of this application, solve the technical problems of this application, and achieve the expected technical effects of this application.

[0055] In the present application, "preferred", "better", "more preferred" and "suitable" are only used to describe implementation methods or examples with better effects. It should be understood that they do not constitute limitations on the scope of protection of the present application.

[0056] In the present application, "further", "further", "particularly" and the like are used for descriptive purposes to indicate differences in content, but should not be construed as limiting the scope of protection of the present application.

[0057] In this application, "optionally", "optional", and "optional" mean optional or dispensable, that is, any one of the two parallel schemes of "yes" or "no". If multiple "options" appear in a technical solution, unless otherwise specified and there is no contradiction or mutual restriction, each "optional" is independent.

[0058] In the present application, the technical features described in an open manner include closed technical solutions composed of the listed features, and also include open technical solutions containing the listed features.

[0059] In the present application, when it comes to numerical intervals (i.e., numerical ranges), unless otherwise specified, the optional numerical distribution is considered continuous within the above numerical interval, and includes the two numerical endpoints (i.e., the minimum and maximum values) of the numerical range, and each numerical value between the two numerical endpoints. Unless otherwise specified, when the numerical interval only refers to the integers within the numerical interval, it includes the two endpoint integers of the numerical range, and each integer between the two endpoints. In this article, it is equivalent to directly listing each integer, such as t is an integer selected from 1 to 10, indicating that t is any integer selected from the group of integers consisting of 1, 2, 3, 4, 5, 6, 7, 8, 9 and 10. In addition, when multiple ranges are provided to describe features or characteristics, these ranges can be combined. In other words, unless otherwise specified, the ranges disclosed herein should be understood to include any and all subranges included therein.

[0060] The temperature parameters in this application, unless otherwise specified, are allowed to be either constant temperature treatment or to vary within a certain temperature range. It should be understood that the constant temperature treatment allows the temperature to fluctuate within the accuracy range controlled by the instrument. Fluctuations within the range of ±5°C, ±4°C, ±3°C, ±2°C, and ±1°C are allowed.

[0061] The "room temperature" in this application generally refers to 5°C to 30°C, preferably 25±5°C.

[0062] All documents mentioned in this application are cited as references in this application, just as each document is cited as reference separately. Unless they conflict with the invention purpose and / or technical solution of this application, the cited documents involved in this application are cited with all contents and all purposes. When the cited documents are involved in this application, the definitions of relevant technical features, terms, nouns, phrases, etc. in the cited documents are also cited. When the cited documents are involved in this application, the examples and preferred methods of the cited relevant technical features can also be incorporated into this application as references, but are limited to the implementation of this application. It should be understood that when the cited content conflicts with the description in this application, the present application shall prevail or be modified adaptively according to the description of this application.

[0063] In this application, if there are multiple steps involved in the method flow, unless there is a clear different description in this document, there is no strict order restriction for the execution of these steps, and they can be executed in other orders than described. Moreover, any step can include multiple sub-steps or multiple stages, and these sub-steps or stages are not necessarily executed at the same time, but can be executed at different times, and their execution order is not necessarily sequential, but can be executed in turn, alternating or simultaneously with other steps or parts of sub-steps or stages of other steps.

[0064] In the present application, unless otherwise specified, “bare cerium oxide” refers to unmodified cerium oxide.

[0065] Cerium (Ce) is the most abundant rare earth element on the Earth's surface, and its outermost electron structure is [Xe]4f 1 5d 1 6s 2 CeO2 has a cubic structure of fluorite and exists in two oxidation states: +3 and +4. Its catalytic application is based on Ce 3+ With Ce 4+ It can be reversibly converted, and the conversion process is accompanied by the generation and elimination of oxygen vacancies. The activity and performance of CeO2 nanoparticles depend on the content of oxygen vacancies. In order to change the degree of oxygen vacancy on the surface of CeO2, people have developed many methods, such as reducing the size of nanoparticles, morphology modification or metal doping. The properties of nanoparticles also depend on different parameters, such as synthesis procedures, solvents or reaction temperature or time. The synthesis strategy of CeO2 nanoparticles is mainly based on physical and chemical methods. Nano-CeO2 can be prepared by physical methods such as pulsed laser ablation in liquid, hydrothermal preparation, spray pyrolysis, chemical vaporization, ball milling, microwave radiation, combustion, etc., and can also be prepared by chemical routes such as co-precipitation, sol-gel method, microemulsion, electrochemistry and photochemistry.

[0066] Traditional methods for synthesizing CeO2 nanoparticles often use hazardous reagents and solvents that produce toxic byproducts to human health and the environment, have long reaction times, multiple steps, and require high vacuum and expensive equipment during the synthesis process. However, these synthetic routes are not suitable when nanoparticles are used in biomedical applications, so a simpler and milder method is needed to synthesize CeO2 nanoparticles, and it is hoped that a cheap and readily available surface modifier can be found to improve the antioxidant activity of CeO2 nanoparticles and expand the research on biological applications, which is very important for the development and application of CeO2 nanoparticles in the field of cosmetics.

[0067] Based on this, the present application at least provides a method for preparing glycerol-modified cerium oxide nanoparticles and its antioxidant application.

[0068] In some embodiments, a method for preparing glycerol-modified cerium oxide nanoparticles is provided, which comprises the following steps: mixing a soluble cerium salt, glycerol and water, adding a precipitant, performing a precipitation reaction, and performing a dehydration reaction to prepare glycerol-modified cerium oxide nanoparticles. By using raw materials including cerium salt and glycerol to prepare glycerol-modified cerium oxide, the reaction system is simple, the reaction conditions are mild, the reaction can be carried out at room temperature and normal pressure, and the reaction time is short.

[0069] In one aspect of the present application, a method for preparing glycerol-modified cerium oxide nanoparticles is provided. The provided preparation method has mild reaction conditions, the surface modification material is cheap and readily available, and the obtained glycerol-modified cerium oxide has high antioxidant activity.

[0070] In a specific embodiment, a method for preparing glycerol-modified cerium oxide nanoparticles is provided, which comprises the following steps: mixing a soluble cerium salt, glycerol and water, adding a precipitant, performing a precipitation reaction, and performing a dehydration reaction to prepare glycerol-modified cerium oxide nanoparticles. The reaction flow diagram can be found in Figure 1 The method provides glycerol-modified cerium oxide nanoparticles, wherein the hydroxyl groups in the glycerol are deprotonated and form a CH2O-Ce complex with cerium oxide in water.

[0071] It is understood that the "cerium salt" referred to in the present application, unless otherwise specified, refers to a soluble cerium salt based on an aqueous solvent.

[0072] In one embodiment, the soluble cerium salt is cerium nitrate or cerium nitrate hydrate. Further, the cerium nitrate hydrate can be but is not limited to cerium nitrate hexahydrate.

[0073] In one embodiment, in the step of mixing the soluble cerium salt, glycerol and water, the mass of glycerol relative to the sum of the mass of the soluble cerium salt and glycerol is 33.3% to 75% based on the feed amount, and can also be 50% to 75%. In the step of mixing the soluble cerium salt, glycerol and water, the mass of glycerol relative to the sum of the mass of the soluble cerium salt and glycerol can also be any of the following percentages or a range selected from any two of the following percentages: 33.3%, 35%, 40%, 45%, 50%, 55%, 60%, 65%, 70%, 75%, etc., without limitation.

[0074] In one embodiment, the step of mixing the soluble cerium salt, glycerol and water comprises: mixing a first aqueous solution containing the soluble cerium salt with a second aqueous solution containing glycerol.

[0075] In one embodiment, the step of mixing the soluble cerium salt, glycerol and water includes: mixing a first aqueous solution in which the soluble cerium salt is completely dissolved with a second aqueous solution in which the glycerol is completely dissolved.

[0076] In one embodiment, in the step of mixing the soluble cerium salt, glycerol and water and adding the precipitant, the volume mass ratio of the precipitant to the soluble cerium salt is (1-1.5) mL / g based on the feed amount.

[0077] In one embodiment, the precipitant is in liquid form, and further, the precipitant may be added dropwise. In a non-limiting manner, the addition rate of the precipitant is 0.3 mL / min to 0.5 mL / min.

[0078] In one embodiment, the precipitant is aqueous ammonia.

[0079] In one embodiment, the mass concentration of the precipitant is 25% to 28%, for example, 25%, 26%, 27% or 28%, and can also be selected from the range consisting of any two of the aforementioned percentages.

[0080] In a specific embodiment, the reaction temperature is 5°C ~ 30°C, for example, 5°C, 6°C, 7°C, 8°C, 9°C, 10°C, 11°C, 12°C, 13°C, 14°C, 15°C, 16°C, 17°C, 18°C, 19°C, 20°C, 21°C, 22°C, 23°C, 24°C, 25°C, 26°C, 27°C, 28°C, 29°C, 30°C or a range composed thereof, and the reaction time is 2h-6h, for example, 2h, 3h, 4h, 5h, 6h or a range selected from any two of the foregoing temperatures.

[0081] In one embodiment, after the precipitation reaction is completed, solid-liquid separation is performed, and the solid obtained by the solid-liquid separation is washed with water and subjected to a dehydration reaction.

[0082] Without limitation, during the dehydration reaction, the cerium hydroxide generated by the precipitation reaction removes water molecules to generate cerium oxide.

[0083] In one embodiment, the dehydration reaction comprises drying at -20°C to 50°C.

[0084] In one embodiment, the dehydration reaction comprises drying at -20°C to 50°C for 20 h to 40 h.

[0085] In one embodiment, the solid obtained by solid-liquid separation is washed with water and then freeze-dried. Non-limitingly, the freeze-drying temperature can be -20°C to -10°C, and can further be any of the following temperatures or a range consisting of any two of the following temperatures: -20°C, -15°C, -20°C. Non-limitingly, the freeze-drying time can be 20h to 40h, and can further be any of the following times or a range consisting of any two of the following times: 20h, 25h, 30h, 35h, 40h.

[0086] In one embodiment, a glycerol-modified cerium oxide nanoparticle is provided, comprising cerium oxide and glycerol modified on the cerium oxide.

[0087] In one embodiment, the potential of the glycerol-modified cerium oxide nanoparticles prepared by the provided preparation method is 35.35 mV to 35.57 mV.

[0088] In one embodiment, the DPPH clearance rate of the glycerol-modified cerium oxide prepared by the preparation method provided is 95.8% to 96.8%, for example, 95.8%, 95.9%, 96.0%, 96.1%, 96.2%, 96.3%, 96.4%, 96.5%, 96.6%, 96.7%, 96.8% or a range selected from any two of the foregoing values.

[0089] In the present application, unless otherwise specified, the DPPH scavenging rate refers to the ratio of DPPH free radicals scavenged by the substance to be tested, calculated by measuring the change in absorbance of the DPPH solution at a specific wavelength before and after the addition of the substance to be tested.

[0090] In one embodiment, the hydrated particle size of the glycerol-modified cerium oxide nanoparticles prepared by the preparation method provided is 8.19 nm ~ 32.44 nm, for example, 8.19 nm, 8.49 nm, 9 nm, 10 nm, 11 nm, 12 nm, 13 nm, 14 nm, 15 nm, 16 nm, 16.32 nm, 17 nm, 18 nm, 19 nm, 20 nm, 21 nm, 22 nm, 23 nm, 24 nm, 25 nm, 26 nm, 27 nm, 28 nm, 28.80 nm, 29 nm, 30 nm, 31 nm, 32 nm, 32.44 nm or a range selected from any two of the foregoing values.

[0091] In one embodiment, the glycerol-modified cerium oxide D prepared by the preparation method provided is hkl The range is 2.66 nm to 4.57 nm, for example, 2.66 nm, 2.72 nm, 3.48 nm, 4.14 nm, 4.57 nm or a range selected from any two of the foregoing values.

[0092] The provided method for preparing glycerol-modified cerium oxide nanoparticles utilizes glycerol to modify cerium oxide. The DPPH clearance rate of the prepared glycerol-modified cerium oxide is greatly improved compared with that of unmodified cerium oxide. The DPPH clearance rate reaches more than 90%, which is better than other polyol-modified cerium oxides. That is, the glycerol-modified cerium oxide has strong antioxidant properties.

[0093] Compared with unmodified CeO2, glycerol-modified CeO2 has smaller particle size, better dispersibility and antioxidant properties.

[0094] In one embodiment, a use of glycerol-modified cerium oxide nanoparticles in eliminating free radicals is provided.

[0095] Without limitation, the free radical scavenging agent may include, but is not limited to, one or more of superoxide anion free radicals, hydroxyl free radicals, hydrogen peroxide, and nitrogen free radicals.

[0096] In one embodiment, a use of glycerol-modified cerium oxide nanoparticles in eliminating one or more free radicals selected from superoxide anion free radicals, hydroxyl free radicals, hydrogen peroxide and nitrogen free radicals is provided.

[0097] In one embodiment, the provided application at least includes application in the preparation of an antioxidant product or an anti-aging product.

[0098] In one embodiment, the provided applications are non-disease diagnostic and therapeutic methods.

[0099] In one embodiment, the provided application is a method for diagnosing and / or treating a disease.

[0100] In one embodiment, a cosmetic, a medicine or a detection reagent is provided, comprising the provided glycerol-modified cerium oxide nanoparticles.

[0101] In one embodiment, a cosmetic is provided that has anti-oxidation and / or anti-aging effects.

[0102] In one embodiment, the active ingredient of the provided medicine comprises glycerol-modified cerium oxide nanoparticles. Optionally, the provided medicine further comprises a pharmaceutically acceptable carrier.

[0103] In this application, unless otherwise specified, "pharmaceutically acceptable" means suitable for administration to subjects within the scope of reasonable medical judgment and commensurate with a reasonable benefit / risk ratio, and can be used to describe ligands, materials, compositions, dosage forms, etc.

[0104] In this application, unless otherwise specified, "pharmaceutically acceptable carrier" refers to a pharmaceutically acceptable material, composition or vehicle, such as a liquid or solid filler, diluent, excipient, solvent or encapsulating material.

[0105] The embodiments of the present application will be described in detail below in conjunction with some examples. It should be understood that these examples are only used to illustrate the present application and are not intended to limit the scope of the present application. The experimental methods for which the conditions are not specified in the following examples are preferably referred to the guidance given in the present application, and can also be based on the experimental manual or normal conditions in the art, or can also be based on the conditions recommended by the manufacturer, or with reference to experimental methods known in the art.

[0106] 1. Preparation Example of Glycerol-Modified Cerium Oxide

[0107] Example 1

[0108] A method for preparing glycerol-modified cerium oxide, wherein, based on the feed amount, the mass of glycerol is 33.3% of the sum of the mass of cerium nitrate and glycerol, and the detailed steps are as follows:

[0109] (1) Dissolve 2.0 g of cerium nitrate in 25 mL of deionized water;

[0110] (2) Dissolve 1.0 g of glycerol in 50 mL of deionized water;

[0111] (3) Add the solution obtained in step (1) to the solution obtained in step (2), and add 2 mL of aqueous ammonia dropwise within 1 minute, and stir at room temperature for 5 h;

[0112] (4) The precipitate was centrifuged at 10,000 rpm for 10 min, washed twice with water, freeze-dried at -15°C for 24 h, and ground to obtain glycerol-modified cerium oxide.

[0113] A method for preparing unmodified cerium oxide, comprising the following steps:

[0114] Take 2.0 g of cerium nitrate and dissolve it in 25 mL of deionized water, add 2 mL of ammonia water dropwise within 1 minute, and stir at room temperature for 5 hours. Centrifuge the precipitate at 10000 rpm for 10 minutes, wash it with water twice, freeze-dry it at -15℃ for 24 hours, and grind it to obtain unmodified cerium oxide.

[0115] XRD tests were performed on unmodified CeO2 and the glycerol-modified cerium oxide obtained in this example. The results can be found in Figure 2 (a) and (b) in the figure. Figure 2 (a) is the detection result of unmodified CeO2. Figure 2 (b) is the test result of glycerol-modified cerium oxide obtained in this example. Figure 2 (a) and Figure 2 As can be seen in (b), both the unmodified CeO2 and the glycerol-modified cerium oxide obtained in this example match the CeO2 standard card and do not form a second phase, indicating that the prepared samples are pure cerium dioxide.

[0116] The final powdered product of unmodified cerium oxide is light yellow in color. Figure 3 a. The final powder product of glycerol-modified cerium oxide is brown-yellow in color, which can be found in Figure 3 b in.

[0117] Example 2

[0118] A method for preparing glycerol-modified cerium oxide, wherein the glycerol-modified cerium oxide is prepared by a method substantially the same as that in Example 1, except that, in step (2), 1.5 g of glycerol is dissolved in 50 mL of deionized water. Based on the amount of feed, the mass of glycerol is 42.9% of the sum of the mass of cerium nitrate and glycerol.

[0119] The glycerol-modified cerium oxide obtained in this example was subjected to XRD detection, and the results can be found in Figure 2 (c) in . Figure 2 As can be seen from (c), the glycerol-modified cerium oxide obtained in this example matches the CeO2 standard card and does not form a second phase, indicating that the prepared sample is pure cerium dioxide.

[0120] The final powder product is brown in color. Figure 3 Middle c.

[0121] Example 3

[0122] A method for preparing glycerol-modified cerium oxide is similar to Example 1, except that, in step (2), 2 g of glycerol is dissolved in 50 mL of deionized water. Based on the amount of feed, the mass of glycerol is 50.0 L% relative to the sum of the mass of cerium nitrate and glycerol.

[0123] The glycerol-modified cerium oxide obtained in this example was subjected to XRD detection, and the results can be found in Figure 2 (d) in. Figure 2 As can be seen from (d), the glycerol-modified cerium oxide obtained in this example matches the CeO2 standard card and does not form a second phase, indicating that the prepared sample is pure cerium dioxide.

[0124] The final powder product is brown in color. Figure 3 Middle d.

[0125] Example 4

[0126] A method for preparing glycerol-modified cerium oxide is similar to Example 1, except that in step (2), 4.0 g of glycerol is dissolved in 50 ml of deionized water. Based on the amount of feed, the mass of glycerol is 66.6% of the sum of the mass of cerium nitrate and glycerol.

[0127] The glycerol-modified cerium oxide obtained in this example was subjected to XRD detection, and the results can be found in Figure 2 (e) in . Figure 2 As can be seen from (e), the glycerol-modified cerium oxide obtained in this example matches the CeO2 standard card and does not form a second phase, indicating that the prepared sample is pure cerium dioxide.

[0128] Thermo Nicolet iS10 Fourier transform infrared (FT-IR) spectrometer was used to detect glycerol, unmodified CeO2 and glycerol-modified cerium oxide obtained in this example by infrared spectroscopy. The test parameters were as follows: background interference was subtracted and the scanning range was 4000 cm -1 ~500cm -1 The results can be found in Figure 4 . Figure 4 In the figure, (a) is the infrared absorption spectrum of glycerol-modified CeO2, (b) is the bare CeO2, and (c) is the infrared absorption spectrum of glycerol. Figure 4 The infrared spectrum shown in the figure shows that 2935 cm -1 and 2852 cm -1 The absorption peaks at 1092 cm-1 correspond to the asymmetric stretching vibration absorption peak and the symmetric stretching vibration absorption peak of CH, respectively, while the absorption peak at 1092 cm-1 -1 and 1025 cm -1 The absorption peaks at 986 cm-1 correspond to the CO stretching vibration absorption peaks of secondary alcohol and primary alcohol, respectively. −1 The absorption peaks of CH on primary C in the glycerol structure are not found in the infrared absorption of bare CeO2. However, the absorption peaks of synthesized glycerol-modified CeO2 are the same as those of glycerol, which proves that glycerol has successfully modified cerium oxide.

[0129] The final powder product is brown in color. Figure 3 Middle e.

[0130] Example 5

[0131] A method for preparing glycerol-modified cerium oxide is similar to Example 1, except that 6 g of glycerol is dissolved in 50 ml of deionized water. Based on the amount of feed, the mass of glycerol is 75.0% of the sum of the mass of cerium nitrate and glycerol.

[0132] The glycerol-modified cerium oxide obtained in this example was subjected to XRD detection, and the results can be found in Figure 2 In (f). Figure 2 As can be seen from (f), the glycerol-modified cerium oxide obtained in this example matches the CeO2 standard card and does not form a second phase, indicating that the prepared sample is pure cerium dioxide.

[0133] The final powder product is brown in color. Figure 3 Middle f.

[0134] Comparative Example 1

[0135] Preparation of ethylene glycol modified cerium oxide:

[0136] The ethylene glycol-modified cerium oxide was prepared by a method similar to that of Example 1, except that in step (2), 1.0 g of ethylene glycol was dissolved in 50 ml of deionized water. Based on the amount of feed, the mass of ethylene glycol was 33.3% of the sum of the mass of cerium nitrate and ethylene glycol.

[0137] Comparative Example 2

[0138] Preparation of a butanediol-modified cerium oxide:

[0139] The butanediol-modified cerium oxide was prepared by a method similar to that of Example 1, except that in step (2), 1.0 g of butanediol was dissolved in 50 ml of deionized water. Based on the amount of feed, the mass of butanediol was 33.3% of the sum of the mass of cerium nitrate and butanediol.

[0140] Comparative Example 3

[0141] Preparation of 1,3-propylene glycol modified cerium oxide:

[0142] 1,3-propylene glycol modified cerium oxide was prepared by a method similar to that of Example 1, except that in step (2), 1.0 g of 1,3-propylene glycol was dissolved in 50 ml of deionized water, and the mass of 1,3-propylene glycol relative to the sum of the masses of cerium nitrate and 1,3-propylene glycol was 33.3% based on the amount of feed.

[0143] Comparative Example 4

[0144] Preparation of 1,2-pentanediol modified cerium oxide:

[0145] 1,2-pentanediol modified cerium oxide was prepared by a method similar to that of Example 1, except that in step (2), 1.0 g of 1,2-pentanediol was dissolved in 50 ml of deionized water. Based on the amount of feed, the mass of 1,2-pentanediol was 33.3% of the sum of the masses of cerium nitrate and 1,2-pentanediol.

[0146] Comparative Example 5

[0147] A preparation method of cerium oxide:

[0148] Take 2.0 g of cerium nitrate and dissolve it in 25 mL of deionized water. Add 2 mL of sodium hydroxide dropwise within 1 minute and stir at room temperature for 5 h.

[0149] The synthesis results can be found in Fig.10 , Fig.10 A in the figure is a picture of all the raw materials mixed before the reaction: Fig.10 B in the figure is the product after the reaction. Fig.10As can be seen from B, only the color changes after the reaction, but no precipitate is produced, that is, no cerium oxide is generated.

[0150] 2. Test and analysis methods

[0151] 1. Hydration particle size and potential test of nanoparticles

[0152] The hydrated particle size and potential were detected using a dynamic light scattering instrument produced by Malvern Panalytical for measuring nanoparticle size and Zeta potential, model Zetasizer Nano ZS (providing basic dynamic light scattering DLS and electrophoretic light scattering ELS functions, suitable for measuring samples with a particle size range of 0.3 nm to 10 μm). The test parameters were a thermal equilibrium time of 60 seconds and three parallel measurements were automatically averaged.

[0153] Among them, Dynamic Light Scattering (DLS) is an effective means to detect the overall particle size distribution of colloidal nanomaterials. DLS technology uses laser to illuminate particles, analyze the light intensity fluctuations of scattered light, and then calculate the particle size of nanoparticles. DLS does not measure the true size of nanoparticles, but the hydraulic diameter of nanoparticles in solution, which is larger than the data measured by electron microscopy.

[0154] 2. Morphology observation and particle size analysis

[0155] Transmission electron microscopy of nanoparticles (JEOL, JSM 2200 FS).

[0156] 3. Grain analysis

[0157] The XRD test was performed using an X-ray diffractometer model D8 Discover produced by Bruker, Germany. The test parameters were conventional wide-angle scanning (scanning range: 10°~90°) and a test time of 20 minutes~30 minutes.

[0158] D hkl Basic principle of detection: When X-rays are incident on small crystals, their diffraction lines will become diffuse and broadened. The smaller the crystal grains, the greater the broadening of the X-ray diffraction bands. Therefore, there is a certain relationship between the grain size and the half-peak width of the XRD spectrum, namely the Scherrer formula. Using the Scherrer formula: Calculate D hkl After appropriate background correction for the X-ray line broadening of the diffraction peak, the average crystal size of the sample can be calculated. hkl represents the crystallite size, λ represents the X-ray diffraction wavelength used, β hkl represents the half-peak width, and θ represents the diffraction angle.

[0159] 4. Dispersion performance test

[0160] 50 mg of the sample to be tested (including the products of Examples 1-5, the products of Comparative Examples 1-4 and unmodified cerium oxide powder) was dispersed in 10 mL of deionized water, ultrasonically dispersed for 20 minutes, and shaken to obtain a 0.5 wt% dispersion. The dispersion was allowed to stand and the amount of precipitation was observed to determine the dispersibility of each sample.

[0161] Test results analysis

[0162] Determination of particle size and potential of cerium oxide The hydrated particle size and potential of unmodified cerium oxide and cerium oxide modified with different concentrations of glycerol in Examples 1-5 were measured using a dynamic light scattering instrument. The results can be found in Figure 5 and Table 1.

[0163] Unmodified cerium oxide and glycerol-modified cerium oxide of Example 4 were photographed using a transmission electron microscope (JEOL, JSM 2200 FS) and particle size analysis was performed. The results can be found in Figure 6 .

[0164] Table 1. Physicochemical data of cerium oxide nanoparticles modified with different concentrations of glycerol

[0165]

[0166] As shown in Table 1, the particle size of glycerol-modified cerium oxide is smaller than that of unmodified cerium oxide, and the potential is lower than that of unmodified cerium oxide.

[0167] The XRD test results can be found in Figure 2 . Figure 2 In the figure, (a) is the XRD pattern of unmodified cerium oxide, (b) is the XRD pattern of glycerol-modified cerium oxide obtained in Example 1, (c) is the XRD pattern of glycerol-modified cerium oxide obtained in Example 2, (d) is the XRD pattern of glycerol-modified cerium oxide obtained in Example 3, (e) is the XRD pattern of glycerol-modified cerium oxide obtained in Example 4, and (f) is the XRD pattern of glycerol-modified cerium oxide obtained in Example 5. Figure 2 The XRD diagram shown was used to calculate the average size of unmodified cerium oxide and glycerol-modified cerium oxide of Examples 1-5 using the Scherrer formula. The results showed that the average particle size of unmodified CeO2 was 8.42 nm, and the average particle size of glycerol-modified CeO2 was 2.66 nm -4.57 nm, both of which were smaller than the average particle size of unmodified CeO2. As the glycerol concentration gradually increased, the particle size gradually decreased.

[0168] The results of the dynamic light scattering test of the hydrated particle size and potential of the product can be found in Figure 5 . Figure 5In the figure, a is the hydrated particle size result of unmodified cerium oxide, b is the hydrated particle size result of glycerol-modified cerium oxide obtained in Example 1, c is the hydrated particle size result of glycerol-modified cerium oxide obtained in Example 2, d is the hydrated particle size result of glycerol-modified cerium oxide obtained in Example 3, e is the hydrated particle size result of glycerol-modified cerium oxide obtained in Example 4, and f is the hydrated particle size result of glycerol-modified cerium oxide obtained in Example 5. From the hydrated particle size result of 5, it can be seen that the particle size of unmodified CeO2 is 42.63±0.99 nm, and the particle size of glycerol-modified CeO2 is 8.19±0.10~32.44±0.55, which is smaller than that of unmodified cerium oxide, and as the amount of glycerol added increases, the particle size of the obtained product gradually decreases.

[0169] The test results of TEM images can be found at Figure 6 , transmission electron microscope took pictures of unmodified CeO2 and glycerol-modified cerium oxide obtained in Example 4, where a is a transmission electron microscope image of unmodified cerium oxide, with a scale bar of 50 nm; b is a transmission electron microscope image of unmodified cerium oxide, with a scale bar of 20 nm; c is a particle size distribution diagram made by statistically analyzing the particle sizes of 50 particles in transmission electron microscope image b using Image J analysis software; d is a transmission electron microscope image of glycerol-modified cerium oxide in Example 4, with a scale bar of 50 nm; e is a transmission electron microscope image of glycerol-modified cerium oxide in Example 4, with a scale bar of 20 nm; f is a particle size distribution diagram made by statistically analyzing the particle sizes of 50 particles in transmission electron microscope image e using Image J analysis software. Figure 6 It can be seen that the product particles of glycerol-modified CeO2 have less aggregation, and the nanoparticles are more dispersed and uniform. 50 particles were counted from the TEM image using Image J analysis software, and the results showed that the average particle size of unmodified CeO2 was 8.03±1.29 nm, and the average particle size of glycerol-modified CeO2 obtained in Example 4 was 2.20±0.33 nm. Taking into account the standard deviation, it can be considered that the particle size value counted in the TEM image is very close to the average particle size value calculated from the X-ray diffraction data, that is, the particle size data shown by TEM and XRD are consistent, and it is confirmed that glycerol-modified CeO2 has a smaller particle size than unmodified CeO2.

[0170] The dispersion test results can be found in Table 2 and Figure 7 . Figure 7 Appearance of dispersions of 0.5 wt % of glycerol-modified cerium oxide of Examples 1-5 and unmodified cerium oxide.

[0171] Table 2

[0172]

[0173] As can be seen from Table 2, the dispersibility of cerium oxide modified with ethylene glycol, butanediol, 1,3-propylene glycol, and 1,2-pentanediol is poor, the dispersibility of cerium oxide modified with 50wt%-75wt% glycerol is good, and the dispersibility of cerium oxide modified with 66.6wt% glycerol has been greatly improved, and finally a clear and transparent yellow solution is presented.

[0174] Figure 7 In the figure, a is a dispersion of 0.5 wt% unmodified cerium oxide, b is a dispersion of 0.5 wt% glycerol-modified cerium oxide obtained in Example 1, c is a dispersion of 0.5 wt% glycerol-modified cerium oxide obtained in Example 2, d is a dispersion of 0.5 wt% glycerol-modified cerium oxide obtained in Example 3, e is a dispersion of 0.5 wt% glycerol-modified cerium oxide obtained in Example 4, and f is a dispersion of 0.5 wt% glycerol-modified cerium oxide obtained in Example 5. Figure 7 It can be seen that as the concentration of the added glycerol increases, the dispersibility of the dispersion obtained by dissolving the synthetic powder in water gradually improves, and finally reaches a clear and transparent yellow solution state. The dispersibility of the products of each embodiment gradually deteriorates in the following order: Example 5, Example 4, Example 3, Example 2, Example 1, unmodified cerium oxide. The dispersibility of the products obtained by Comparative Example 1, Comparative Example 2, Comparative Example 3, and Comparative Example 4 is worse than that of the product of Example 1, and better than that of unmodified cerium oxide.

[0175] 3. Effect test:

[0176] DPPH free radical scavenging efficacy test

[0177] The DPPH free radical scavenging effects of the products of Examples 1-5, the products of Comparative Examples 1-4 and unmodified cerium oxide were determined.

[0178] DPPH (1,1-disphenyl-2-picryl-hydrazyl), chemically named 1,1-diphenyl-2-trinitrophenylhydrazine, has a molecular formula of (C6H5)2N-NC6H2(NO2)3. In this compound, there is an unpaired valence electron on one atom of the nitrogen bridge, and the orbital motion of this electron is almost offset by the molecular structure. The capture of DPPH free radicals is usually used as an indicator for assessing antioxidant capacity. DPPH is a stable organic free radical with a maximum absorption peak of 517 nm in the visible light region. In ethanol solution, each DPPH molecule can generate a stable nitrogen-containing free radical in the solution with a typical purple color. When it reacts with a free radical scavenger that provides 1 electron (for example, cerium oxide dispersion), a colorless product is generated, which makes the typical purple color of the solution lighter. The degree of fading is stoichiometrically related to the number of paired electrons. Therefore, spectrophotometry can be used for quantitative analysis to detect the free radical scavenging situation, thereby evaluating the free radical scavenging ability of the sample. The reaction process of cerium oxide scavenging DPPH is as follows:

[0179]

[0180] 3.1. Instruments and reagents

[0181] (1) Analytical balance (d = 0.1 mg, purchased from Sartorius, model: BSA2202S-CW, Max 220 g);

[0182] (2) Vortex mixer (model MX-F);

[0183] (3) Multifunctional microplate reader (purchased from Tecan), 96-well plate (model: jet)

[0184] (4) Pipette (5 mL, 200 μL, 1000 μL, purchased from Eppendorf);

[0185] (5) DPPH (purchased from Sigma, analytical grade, C 18 H 12 N5O6, molecular weight 394.32);

[0186] (6) Anhydrous ethanol (purchased from Sinopharm Chemical Reagent Co., Ltd., analytical grade).

[0187] 3.2. Experimental preparation

[0188] 3.2.1 Reagent preparation

[0189] (1) 0.2 mmol / L DPPH solution

[0190] Weigh 0.0200 g DPPH, add anhydrous ethanol to dissolve and dilute to a 250 mL volumetric flask, and shake well.

[0191] (2) 0.5 wt% cerium oxide dispersion

[0192] Take 50 mg of the cerium oxide sample to be tested, disperse it in 10 mL of deionized water, ultrasonically disperse it for 20 minutes, and shake it well to obtain a 0.5 wt% cerium oxide dispersion.

[0193] 3.3. Experimental operation

[0194] Set up a blank group C, a negative control group B, and a sample group A (assuming 10 samples are tested) respectively.

[0195] 3.4. Result processing

[0196] The calculation formula of DPPH free radical scavenging rate is:

[0197] Where:

[0198] A——Absorbance at 517 nm after the sample solution is mixed with the DPPH solution

[0199] B——Absorbance at 517 nm after mixing anhydrous ethanol and DPPH solution

[0200] C——Absorbance value after mixing anhydrous ethanol and sample solution.

[0201] 3.5. Experimental operation process

[0202] Set up blank group C, negative control group B, and sample group A (at least 10 samples) respectively. The specific sample addition order and dosage are shown in Table 3 and Table 4:

[0203] Table 3. Reagent additions in sample tubes

[0204]

[0205] Table 4. Reagent additions in sample tubes

[0206]

[0207] It should be noted that A1-A10, A1'-A10', A1''-A10'' represent three parallel groups, and each parallel group of cerium oxide products is set with 10 samples for 10 parallel measurements.

[0208] 3.6. Results analysis

[0209] The results can be found in Table 5 and Figure 8 , Fig. 9 . Figure 8 The results show the scavenging effect of glycerol-modified cerium oxide on DPPH free radicals in Examples 1-5. Fig. 9 Shown are the results of scavenging DPPH free radicals by glycerol-modified cerium oxide obtained in Example 1 and ethylene glycol, butanediol, 1,3-propylene glycol, and 1,2-pentanediol-modified cerium oxide in Comparative Examples 1-4.

[0210] Table 5. DPPH scavenging efficiency of different cerium oxide nanoparticles

[0211]

[0212] From Table 5 and Figure 8 , Fig. 9 It can be seen that the DPPH free radical scavenging effect of cerium oxide modified with glycerol at a concentration of 33.3wt% to 75.0wt% in Examples 1-5 reached 95.8% to 96.8%, while the DPPH free radical scavenging effect of cerium oxide modified with ethylene glycol, butanediol, 1,3-propylene glycol, and 1,2-pentanediol in Comparative Examples 1-4 was poor. The DPPH free radical scavenging effect of unmodified cerium oxide was poor.

[0213] The technical features of the above-described embodiments may be arbitrarily combined. To make the description concise, not all possible combinations of the technical features in the above-described embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0214] The above-mentioned embodiments only express several implementation methods of the present invention, and the descriptions thereof are relatively specific and detailed, but they cannot be understood as limiting the scope of the invention patent. It should be pointed out that, for ordinary technicians in this field, several variations and improvements can be made without departing from the concept of the present invention, and these all belong to the protection scope of the present invention. Therefore, the protection scope of the patent of the present invention shall be subject to the attached claims.

Claims

1. A method for preparing glycerol-modified cerium oxide nanoparticles, characterized in that: The steps include: Soluble cerium salt, glycerol and water are mixed, a precipitant is added, precipitation reaction and dehydration reaction are carried out, and glycerol-modified cerium oxide nanoparticles are prepared.

2. The preparation method according to claim 1, characterized in that: Meet one or more of the following characteristics: The soluble cerium salt is cerium nitrate or cerium nitrate hexahydrate; In the step of mixing the soluble cerium salt, glycerol and water, the mass of glycerol relative to the sum of the mass of the soluble cerium salt and glycerol is 33.3% to 75% based on the amount of feed; The step of mixing the soluble cerium salt, glycerol and water comprises: mixing a first aqueous solution containing the soluble cerium salt and a second aqueous solution containing glycerol.

3. The preparation method according to claim 2, characterized in that: In the step of mixing the soluble cerium salt, glycerol and water, the mass of glycerol accounts for 50% to 75% of the sum of the masses of the soluble cerium salt and glycerol, based on the feed amount.

4. The preparation method according to any one of claims 1 to 3, characterized in that Meet one or more of the following characteristics: In the step of mixing the soluble cerium salt, glycerol and water and adding the precipitant, the volume mass ratio of the precipitant to the soluble cerium salt is (1-1.5) mL / g based on the amount of feed; The precipitant is in liquid form, and is added dropwise; The precipitant is added at a rate of 0.3 mL / min to 0.5 mL / min; The precipitant is aqueous ammonia; The mass concentration of the precipitant is 25% to 28%.

5. The preparation method according to any one of claims 1 to 3, characterized in that: Meet one or more of the following characteristics: In the step of performing the precipitation reaction, the reaction temperature is 5°C to 30°C; In the step of performing the precipitation reaction, the reaction time is 2h~6h.

6. The preparation method according to any one of claims 1 to 3, characterized in that: After the precipitation reaction is finished, the following steps are also included: solid-liquid separation, collecting the solid phase, washing with water, and performing a dehydration reaction; Optionally, the dehydration reaction includes drying at -20°C to 50°C.

7. A glycerol-modified cerium oxide nanoparticle, characterized in that: The invention comprises cerium oxide and glycerol modified on the cerium oxide.

8. The glycerol-modified cerium oxide nanoparticles according to claim 7, characterized in that: The glycerol-modified cerium oxide nanoparticles meet at least one of the following conditions: The potential is 35.35 mV~35.57 mV; The DPPH clearance rate was 95.8%~96.8%; The hydrated particle size is 8.19 nm~32.44 nm; D hkl is 2.66nm~4.57nm; among them, D hkl is the crystallite size; The glycerol-modified cerium oxide nanoparticles are prepared according to the method for preparing glycerol-modified cerium oxide nanoparticles according to any one of claims 1 to 6.

9. Use of the glycerol-modified cerium oxide nanoparticles according to claim 7 or 8 in eliminating free radicals; in, The free radicals include one or more of superoxide anion free radicals, hydroxyl free radicals, hydrogen peroxide and nitrogen free radicals; Optionally, the application is not a method for diagnosing or treating a disease.

10. A cosmetic, medicine or detection reagent, characterized in that: Containing the glycerol-modified cerium oxide nanoparticles according to claim 7 or 8.

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