Nanometer material with noble metal coated silver-based core-shell structure, preparation method and application thereof

Abstract

The application discloses a kind of noble metal coated silver-based core-shell structure nanomaterial, preparation method and application thereof.The method uses mild non-toxic aqueous system, utilizes green small molecule compound, silver source, tellurium or selenium source, gold or platinum source to realize one-pot preparation of noble metal coated silver-based core-shell structure nanocluster with enzyme-like activity and fluorescence effect.The reaction condition of the application is mild and controllable, simple to operate, and has good repeatability.The noble metal coated silver-based core-shell structure nanocluster prepared has good monodispersity, and has peroxidase-like, catalase-like, superoxide dismutase-like activity and fluorescence effect, can be adjusted to realize particle size, enzyme-like activity and fluorescence emission wavelength regulation, and is easy to surface functionalization modification, suitable for a variety of biomedical detection scenarios.

Description

Technical Field

[0001] This invention belongs to the field of biomedical nanotechnology, and relates to a noble metal-coated silver-based core-shell structured nanomaterial, its preparation method, and its application. Background Technology

[0002] Silver-based semiconductor materials possess suitable band structures, enabling near-infrared fluorescence emission with tunable wavelengths over a wide range, which has important applications in biomedical in vivo imaging and in vitro detection. The fluorescence emission wavelength, fluorescence quantum yield, and enzyme-like catalytic activity of nanomaterials are all significantly related to their size; therefore, small-sized nanoclusters have significant research and application value.

[0003] Most reported silver-based semiconductor materials are synthesized organically. For example, Reference 1 uses tri-n-butylphosphine to dissolve tellurium powder and reacts it in dodecanethiol at 120°C to prepare silver telluride nanoparticles. After the reaction, the product is dissolved in chloroform, and then the silver telluride particles are mixed with a chloroform-oleylamine mixture of chloroauric acid to obtain gold-coated silver telluride nanoparticles (Yang H, Huang H, Ma X, et al. Advanced Materials, 2021, 33(37): 2103953.). Although there are a few reports of aqueous synthesis, they are all for silver telluride, and no aqueous synthesis method for gold-coated silver telluride materials has been proposed. For example, Reference 2 uses hydrazine and ammonia as reducing agents and buffers to prepare silver telluride nanoparticles. Although aqueous phase synthesis was achieved, the reducing agent is flammable, explosive, and carcinogenic (Chang Y, Guo J, Tang YQ, et al. CrystEngComm, 2019, 21(11): 1718-1727.). In addition, silver-based semiconductor nanomaterials synthesized directly in aqueous phase often have large particle sizes, which cannot fully utilize their superior properties. On the other hand, organically synthesized nanomaterials are not conducive to subsequent biological applications and often need to be converted from organic phase nanomaterials to aqueous phase. On the one hand, most organic synthesis methods require the use of some biotoxic reagents. On the other hand, adding the step of converting to aqueous phase is not only cumbersome, but also inevitably causes a certain degree of material loss and property change during the process, often resulting in increased particle size and reduced morphological uniformity.

[0004] Furthermore, since Academician Yan Xiyun proposed the concept of "nanozymes," nanozymes have gradually become a powerful supplement to natural enzymes. The fluorescence properties of nanomaterials are similar to the correlation between enzyme-like activity and size; therefore, these two properties can be combined to establish a multimodal detection method. First, there are currently no reports on the enzyme-like properties of silver-based semiconductor materials. Second, silver-based semiconductor materials have certain biotoxicity, while gold-based nanomaterials have good biocompatibility, stable chemical properties, are easy to functionalize, and possess excellent enzyme-like and fluorescence properties. Therefore, using gold to modify the surface of silver-based semiconductor materials can significantly improve their biosafety, expand their application scenarios, and simultaneously enhance their enzyme-like and fluorescence properties.

[0005] Therefore, developing a simple, environmentally friendly, one-pot preparation method that can directly obtain water dispersibility, enabling the controllable synthesis of small-sized core-shell structured nanoclusters of precious metal-shell silver-based semiconductor materials, and developing their enzyme-like properties for biomedical applications, has significant research and application value. Summary of the Invention

[0006] The present invention aims to provide a noble metal-coated silver-based core-shell nanomaterial, its preparation method, and its application. This method optimizes the surface properties of the silver-based semiconductor material by coating it with a noble metal shell, thereby obtaining a noble metal-coated silver-based core-shell nanomaterial with synergistically enhanced fluorescence and enzyme-like activity.

[0007] The technical solution for achieving the objective of this invention is as follows:

[0008] A method for preparing noble metal-coated silver-based core-shell structured nanomaterials includes the following steps:

[0009] The pH of the deoxygenated water-soluble silver source solution was adjusted to 8–11.5, and an aqueous solution of the deoxygenated capping agent and a deoxygenated water-soluble tellurium source or water-soluble selenium source solution were added. The reaction was carried out at 60±5℃ for 80±10 min. Then, a deoxygenated water-soluble gold source or platinum source solution was added to the system after the reaction. After the reaction was completed, the system was adjusted to room temperature to obtain noble metal-coated silver-based core-shell structured nanomaterials. The capping agent is glutathione (GSH), cysteine ​​(L-Cys), bovine serum albumin (BSA), guanidine hydrochloride denatured BSA, tris(2-carbonylethyl) phosphate hydrochloride denatured BSA, or guanidine hydrochloride and tris(2-carbonylethyl) phosphate hydrochloride double denatured BSA.

[0010] Furthermore, the water-soluble silver source is a commonly used water-soluble silver source in the preparation of silver-based nanomaterials, such as silver acetate, silver nitrate, or silver lactate. In a specific embodiment of the present invention, silver acetate is used as a representative example.

[0011] Furthermore, the pH of the reaction system is adjusted to 8–11.5 using an alkaline solution, selected from sodium hydroxide solution, sodium carbonate solution, potassium hydroxide solution, potassium carbonate solution, or ammonia solution. In a specific embodiment of the present invention, sodium hydroxide solution is used as a representative example.

[0012] Furthermore, the preparation methods of the guanidine hydrochloride-denatured BSA, tris(2-carbonylethyl) phosphate hydrochloride-denatured BSA, and guanidine hydrochloride and tris(2-carbonylethyl) phosphate hydrochloride-double-denatured BSA are as follows: under an ice-water bath, guanidine hydrochloride, tris(2-carbonylethyl) phosphate hydrochloride, or guanidine hydrochloride and tris(2-carbonylethyl) phosphate hydrochloride are mixed with BSA and stirred to react, thereby obtaining denatured BSA.

[0013] Furthermore, when the capping agent is BSA, guanidine hydrochloride-modified BSA, tris(2-carbonylethyl)phosphohydrochloride-modified BSA, or guanidine hydrochloride and tris(2-carbonylethyl)phosphohydrochloride-double-modified BSA, the reaction temperature after adding the deoxygenated water-soluble gold or platinum source solution is 0-50℃, and the molar ratio of water-soluble silver source, water-soluble gold source, or platinum source is 2-16:1.

[0014] Furthermore, when the capping agent is L-Cys, the reaction temperature after adding the deoxygenated water-soluble gold or platinum source solution is 0-95℃, and the molar ratio of water-soluble silver, water-soluble gold, or platinum source is 1.33-16:1.

[0015] Furthermore, when the capping agent is GSH, the reaction temperature after adding the deoxygenated water-soluble gold or platinum source solution is 0-95℃, and the molar ratio of water-soluble silver source, water-soluble gold source, or platinum source is 16:1.

[0016] Furthermore, the water-soluble tellurium source is sodium telluride or sodium telluride hydride, the water-soluble selenium source is sodium selenide or sodium selenide hydride, the water-soluble gold source is chloroauric acid (HAuCl4), and the water-soluble platinum source is chloroplatinic acid.

[0017] Furthermore, the stirring speed is 700–1100 rpm.

[0018] This invention provides a noble metal-coated silver-based core-shell structured nanomaterial prepared by the above-described method.

[0019] Furthermore, this invention provides the application of the above-mentioned noble metal-coated silver-based core-shell structured nanomaterials as peroxidase-like substances in blood glucose detection.

[0020] Furthermore, this invention provides the application of metal-coated silver-based core-shell nanomaterials in the immunohistochemical detection of breast cancer tissue sections by catalyzing the oxidation of 3',3-diaminobenzidine by H2O2.

[0021] This invention selects a specific capping agent and uses it as a reducing agent and stabilizer. The tellurium source and the silver source react to generate silver telluride nanoparticles modified with the capping agent. The remaining capping agent continues to reduce the high-valence gold to elemental form and grows on the silver telluride core to form a gold-coated silver telluride structure.

[0022] Compared with the prior art, the present invention has the following advantages:

[0023] (1) The process of this invention is simple and the raw materials are green and environmentally friendly. It can directly obtain water-dispersible gold (platinum)-coated silver telluride (selenide) core-shell structured nanoclusters through a one-pot method. It is also easy to perform surface functionalization modification. On the one hand, the noble metal shell can optimize the surface properties of silver-based semiconductor materials and expand the application scenarios. On the other hand, the properties of noble metal and silver-based semiconductor nanomaterials are mutually enhanced, and thus their fluorescence effect and enzyme-like activity can be utilized to realize a variety of biomedical detection.

[0024] (2) The gold (platinum)-coated silver telluride (selenide) core-shell structured nanoclusters synthesized in this invention simultaneously possess peroxidase-like, catalase-like, and superoxide dismutase-like activities. The particle size and enzyme-like activities can be regulated by adjusting the thickness of the gold shell, making it a powerful supplement to natural enzymes for in vitro detection and in vivo treatment based on enzyme-catalyzed reactions.

[0025] (3) The gold (platinum)-coated silver telluride (selenide) core-shell structured nanoclusters synthesized in this invention can have their fluorescence emission wavelength adjusted between 600-1100 nm by adjusting the thickness of the gold shell. They can be used for in vivo fluorescence imaging and in vitro fluorescence detection, and can be used in combination with enzyme-like activities to achieve in vivo diagnosis and treatment integration and in vitro dual-modal detection. Attached Figure Description

[0026] Figure 1 Images show gold-coated silver telluride prepared under different capping agents, reaction temperatures, and amounts of HAuCl4. (a) BSA, 0℃, 0.625 μmol HAuCl4; (b) BSA, 25℃, 0.625 μmol HAuCl4; (c) BSA, 37℃, 2.5 μmol HAuCl4; (d) BSA, 50℃, 0.625 μmol HAuCl4; (e) BSA, 50℃, 2.5 μmol HAuCl4; (f) L-Cys, 0℃, 0.625 μmol HAuCl4; (g) L-Cys, 0℃, 1.25 μmol HAuCl4; (h) L-Cys, 0℃, 2.5 μmol HAuCl4; (i) L-Cys, 0℃, 5 μmol HAuCl4. HAuCl4, (j)L-Cys, 0℃, 7.5μmol HAuCl 4。

[0027] Figure 2The image shows a transmission electron microscope image of gold-coated silver telluride prepared under different reaction temperatures and amounts of HAuCl4 using BSA as the capping agent in Example 1.

[0028] Figure 3 Transmission electron microscope images of gold-coated silver telluride synthesized by using guanidine hydrochloride-modified BSA, tris(2-carbonylethyl)phosphohydrochloride-modified BSA, and guanidine hydrochloride and tris(2-carbonylethyl)phosphohydrochloride-double-modified BSA as end-capping agents at a reaction temperature of 0 °C and a core-shell molar ratio of 1:1.

[0029] Figure 4 Transmission electron microscope images of gold-coated silver telluride synthesized with L-Cys as the capping agent at different reaction temperatures and amounts of HAuCl4.

[0030] Figure 5 Fluorescence emission patterns of silver telluride, silver selenide, and gold-coated silver telluride with a core-shell molar ratio of 1:1 synthesized at 95 °C using L-Cys as the end-capping agent.

[0031] Figure 6 The image shows the results of gold-coated silver telluride core-shell nanoclusters synthesized at 0℃ with BSA as the capping agent and a core-shell molar ratio of 2:1, as a peroxidase-like enzyme for detecting 0-30% H2O2 (ABTS colorimetric method). (a) Within the 0-30% range, the detection results show a significant gradient difference with increasing H2O2 concentration; (b) Within the 0-7.5% range, the detection results show good linearity, with a correlation coefficient (R0). 2 0.9971, linear formula y = 15.217x + 0.4113.

[0032] Figure 7 The image shows the results of gold-coated silver telluride core-shell nanoclusters synthesized with GSH as the end-capping agent at 0 and 95 °C and a core-shell molar ratio of 2:1, respectively, as peroxidase-like detection of 0-30% H2O2 (ABTS colorimetric method).

[0033] Figure 8 The image shows the results of gold-coated silver telluride core-shell nanoclusters synthesized at 0 and 95 °C with L-Cys as the end-capping agent, and at a core-shell molar ratio of 2:1, as peroxidase-like detection of 0-30% H2O2 (ABTS colorimetric method).

[0034] Figure 9 Using BSA as a capping agent, gold-coated silver telluride core-shell nanoclusters were synthesized at 0℃ with a core-shell molar ratio of 2:1. These nanoclusters served as an immunoprobe constructed from peroxidase-like molecules, catalyzing the oxidation of 3',3-diaminobenzidine by H2O2 to achieve immunohistochemical detection of breast cancer tissue sections. (a) is a schematic diagram of the principle, and (b) is a microscopic image of the detection results.

[0035] Figure 10 The activity characterization results of gold-coated silver telluride core-shell structured nanoclusters of glucose oxidase prepared with different end-capping agents are shown in the figure. The substrate was 0.28M glucose, and the reaction time was 300s.

[0036] Figure 11 Using BSA as the capping agent, gold-coated silver telluride core-shell nanoclusters synthesized at 0℃ and a core-shell molar ratio of 16:1 serve as glucose oxidase-like enzymes for blood glucose detection. The results are shown in the figure for detection within the common blood glucose range of 2.4–35.5 mM.

[0037] Figure 12 The image shows a transmission electron microscope (TEM) image of gold-coated silver telluride synthesized at 95 °C with 3-mercaptopropionic acid and thioglycolic acid as capping agents, respectively, in a core-shell molar ratio of 1:1. Detailed Implementation

[0038] The present invention will now be described in further detail with reference to specific embodiments and accompanying drawings.

[0039] Example 1

[0040] Preparation of gold-coated silver telluride core-shell nanoclusters with BSA as the capping agent:

[0041] Under nitrogen protection, 10 μmol of tellurium powder was added to 4 mL of boiling water, followed by 2.5 mmol of sodium borohydride aqueous solution to obtain sodium telluride aqueous solution. Under nitrogen protection, 20 μmol of silver acetate was dissolved in 85 mL of pure water, and the pH of the reaction system was adjusted to 10 with 1 M sodium hydroxide aqueous solution. While stirring, 1 mmol of bovine serum albumin aqueous solution was added to the above sodium telluride aqueous solution, and the reaction was carried out at 60 °C for 80 min. Then, 0.625 μmol (core-shell molar ratio 16:1), 2.5 μmol (core-shell molar ratio 4:1), and 5 μmol (core-shell molar ratio 2:1) of HAuCl4 aqueous solution were added to the resulting solution, and the reactions were carried out at 0 °C, 25 °C, 37 °C, and 50 °C for 30 min, respectively. After the reaction, the solution was cooled or heated to room temperature to obtain gold-coated silver telluride core-shell structured nanoclusters, which were stored at 4 °C in the dark.

[0042] like Figure 1 and Figure 2 As shown, the gold-coated silver telluride core-shell nanoclusters prepared in Example 1 were all aqueously dispersed, and their monodispersity was observed to be good under a transmission electron microscope.

[0043] The gold-coated silver telluride core-shell nanoclusters prepared in Example 1 exhibit pH-regulated peroxidase-like and catalase-like activities. They show catalase-like activity at pH > 5 and peroxidase-like activity at pH < 5. Taking the gold-coated silver telluride core-shell nanoclusters synthesized at a reaction temperature of 0℃ and a chloroauric acid feed amount of 5 μmol (core-shell molar ratio 2:1) as an example, they were used as a peroxidase for detecting 0-30% H2O2 (ABTS colorimetric method). The results are as follows... Figure 6 As shown, within the range of 0-30%, the detection results exhibit a significant gradient difference with increasing H2O2 concentration; within the range of 0-7.5%, the detection results show good linearity, with a correlation coefficient (R0). 2 The value is 0.9971, and the linear formula is y = 15.217x + 0.4113. For example... Figure 10 As shown, the gold-coated silver telluride core-shell nanoclusters prepared in Example 1 all exhibited glucose oxidase-like activity. The fluorescence emission wavelength of the gold-coated silver telluride core-shell nanoclusters prepared in Example 1 was tunable from 600 to 1100 nm under 305 nm excitation.

[0044] Example 2

[0045] Preparation of gold-coated silver telluride core-shell nanoclusters using guanidine hydrochloride-modified BSA, tris(2-carbonylethyl) phosphate hydrochloride-modified BSA, and guanidine hydrochloride and tris(2-carbonylethyl) phosphate hydrochloride-modified BSA as end-capping agents:

[0046] In an ice-water bath, 3 mmol of guanidine hydrochloride was mixed with 2 mmol of BSA and stirred at 300 rpm for 60 min to obtain guanidine hydrochloride-denatured BSA. In an ice-water bath, 2.5 μmol of tris(2-carbonylethyl) phosphate hydrochloride was mixed with 2 mmol of BSA and stirred at 300 rpm for 60 min to obtain tris(2-carbonylethyl) phosphate hydrochloride-denatured BSA. In an ice-water bath, 3 mmol of guanidine hydrochloride was first mixed with 2 mmol of BSA, and after 15 min, 2.5 μmol of tris(2-carbonylethyl) phosphate hydrochloride was added, and the mixture was stirred at 300 rpm for 60 min to obtain guanidine hydrochloride and tris(2-carbonylethyl) phosphate hydrochloride-double-denatured BSA.

[0047] Under nitrogen protection, 10 μmol of tellurium powder was added to 4 mL of boiling water, followed by 2.5 mmol of sodium borohydride aqueous solution to obtain sodium telluride aqueous solution. Under nitrogen protection, 20 μmol of silver acetate was dissolved in 85 mL of pure water, and the pH of the reaction system was adjusted to 10 with 1 M sodium hydroxide aqueous solution. While stirring, 1 mmol of denatured BSA aqueous solution was added to the above sodium telluride aqueous solution, and the reaction was carried out at 60 °C for 80 min. Then, 0.625, 1.25, 2.5, 5, and 7.5 μmol of chloroauric acid aqueous solution were added to the resulting solution, and the reactions were carried out for 30 min. After the reaction was completed, the solution was cooled to room temperature to obtain gold-coated silver telluride core-shell structured nanoclusters, which were stored at 4 °C in the dark.

[0048] like Figure 3 As shown, the gold-coated silver telluride core-shell nanoclusters prepared in Example 2 were all aqueously dispersed, and their monodispersity was observed to be good under a transmission electron microscope. The gold-coated silver telluride core-shell nanoclusters prepared in Example 2 exhibit glucose oxidase and pH-regulated peroxidase / catalase-like activities; they exhibit catalase-like activity at pH > 5 and peroxidase-like activity at pH < 5. The fluorescence emission wavelength of the gold-coated silver telluride core-shell nanoclusters prepared in Example 2 was tunable from 600 to 1100 nm under 305 nm excitation.

[0049] Example 3

[0050] Preparation of gold-coated silver telluride core-shell nanoclusters with L-Cys as end-capping agent:

[0051] Under nitrogen protection, 10 μmol of tellurium powder was added to 4 mL of boiling water, followed by 2.5 mmol of sodium borohydride aqueous solution to obtain sodium telluride aqueous solution. Under nitrogen protection, 20 μmol of silver acetate was dissolved in 85 mL of pure water, and the pH of the reaction system was adjusted to 10 with 1 M sodium hydroxide aqueous solution. While stirring, 1 mmol of L-Cys aqueous solution was added to the sodium telluride aqueous solution, and the reaction was carried out at 60 °C for 80 min. Then, 0.625, 1.25, 2.5, 5, and 7.5 μmol of chloroauric acid aqueous solution were added to the resulting solution, and the reactions were carried out at 0 °C and 95 °C for 30 min, respectively. After the reaction was completed, the solution was cooled to room temperature to obtain gold-coated silver telluride core-shell structured nanoclusters, which were stored at 4 °C in the dark.

[0052] like Figure 1 and Figure 4 As shown, the gold-coated silver telluride core-shell nanoclusters prepared in Example 3 were all aqueously dispersed, and their monodispersity was observed to be good under a transmission electron microscope. The gold-coated silver telluride core-shell nanoclusters prepared in Example 3 exhibited pH-regulated peroxidase-like and catalase-like activities; they exhibited catalase-like activity at pH > 6 and peroxidase-like activity at pH < 6. Figure 8As shown, it was used as a peroxidase-like assay for detecting 0-30% H2O2 (ABTS colorimetric method). The results showed that within the range of 0-30%, the detection results exhibited a significant gradient difference as the H2O2 concentration increased.

[0053] like Figure 10 As shown, the gold-coated silver telluride core-shell nanoclusters prepared in Example 3 only exhibited glucose oxidase-like activity when the gold content was 0.625 μmol. Figure 5 As shown, the gold-coated silver telluride core-shell structured nanoclusters prepared in Example 3 exhibit tunable fluorescence emission wavelengths of 600-1100 nm under 305 nm excitation. The gold-coated silver telluride synthesized at a reaction temperature of 95 °C and a core-shell molar ratio of 1:1 has an emission peak of 680 nm, which is higher than that of silver telluride and silver selenide synthesized at the same reaction temperature and with the same capping agent.

[0054] Example 4

[0055] Preparation of gold-coated silver telluride core-shell nanoclusters with GSH as the capping agent:

[0056] Under nitrogen protection, 10 μmol of tellurium powder was added to 4 mL of boiling water, followed by 2.5 mmol of sodium borohydride aqueous solution to obtain sodium telluride aqueous solution. Under nitrogen protection, 20 μmol of silver acetate was dissolved in 85 mL of pure water, and the pH of the reaction system was adjusted to 10 with 1 M sodium hydroxide aqueous solution. While stirring, 1 mmol of GSH aqueous solution was added to the sodium telluride aqueous solution, and the reaction was carried out at 60 °C for 80 min. 0.625 μmol of chloroauric acid aqueous solution was added to the resulting solution, and the reactions were carried out at 0 °C and 95 °C for 30 min, respectively. After the reaction, the solution was cooled or heated to room temperature to obtain gold-coated silver telluride core-shell structured nanoclusters, which were stored at 4 °C in the dark.

[0057] The gold-coated silver telluride core-shell nanoclusters prepared in Example 4 were all aqueously dispersed, and their monodispersity was observed to be good under a transmission electron microscope. The gold-coated silver telluride core-shell nanoclusters prepared in Example 4 exhibited pH-regulated peroxidase / catalase-like activities; they exhibited catalase-like activity at pH > 5 and peroxidase-like activity at pH < 5. Figure 7 As shown, it was used as a peroxidase-like assay for detecting 0-30% H2O2 (ABTS colorimetric method). The results showed that within the 0-30% range, the detection results exhibited a significant gradient difference with increasing H2O2 concentration. The gold-coated silver telluride core-shell nanoclusters prepared in Example 4 exhibited tunable fluorescence emission wavelengths from 600-1100 nm under 305 nm excitation.

[0058] Example 5

[0059] Gold-coated silver telluride core-shell nanoclusters as glucose oxidase-like enzymes for blood glucose detection:

[0060] The gold-coated silver telluride core-shell nanoclusters synthesized under the conditions of BSA as the capping agent, reaction temperature of 0℃, and HAuCl4 usage of 0.625 μmol (core-shell molar ratio of 16:1) in Example 1 were mixed with 3,3',5,5'-tetramethylbenzidine (1 μL, 10 mg / ml) and BR buffer (50 μL, 0.02 M, pH 3.0), and 50 μL of serum sample was added. After standing at room temperature for 5 min, the absorbance at 405 nm was read.

[0061] like Figure 11 As shown, gold-coated silver telluride core-shell nanoclusters, used as peroxidase-like enzymes for blood glucose detection, exhibited good linearity in the common blood glucose range of 2.4–35.5 mM, with a correlation coefficient (R0). 2 The linear formula y = 0.0445x + 0.1737, with a value of 0.9991, can achieve a detection effect similar to that of natural enzymes.

[0062] Example 6

[0063] Gold-coated silver telluride core-shell nanoclusters, used as peroxidase-like enzymes, for immunohistochemical detection in tissue sections:

[0064] 1. Probe preparation

[0065] The pH of 50 μg polystyrene microspheres (30 nm) was adjusted to 9.5 using 0.1 mol / L potassium carbonate solution. 20 μg of universal mouse and rabbit enzyme-labeled secondary antibody was added, and the reaction volume was set at 1 mL. After shaking, the mixture was allowed to stand for 30 min. Then, 5 mL of gold-coated silver telluride core-shell nanoclusters synthesized in Example 1 under the conditions of using BSA as the capping agent, reaction temperature at 0 °C, and 0.625 μmol of HAuCl4 (core-shell molar ratio 16:1) were added as the blocking agent and the mixture was blocked for 15 min. After centrifugation at 10,000 rpm for 20 min, the precipitate was dissolved in 1% BSA in PBS solution (pH = 8.0) as a peroxidase-like probe.

[0066] 2. Pathological section examination

[0067] HER2-overexpressing breast cancer tissue sections were baked in a 90°C oven for 40 min; soaked in xylene three times for 10 min each time; soaked in anhydrous ethanol twice for 10 min each time; then soaked in a series of ethanol solutions (95%, 90%, 80%, 70%) for 10 min each time; rinsed with distilled water; the sections were placed in a stainless steel pressure cooker after slightly heating the citrate antigen retrieval solution (pH 6.0) to boiling, pressurized for 5 min, then the heat was turned off, and the pressure cooker was cooled with cold water before the sections were removed; PBS- Wash with 0.05% Tween-20; add polyclonal rabbit anti-human HER2 oncoprotein and incubate overnight at 4°C; add the above-mentioned peroxidase-like probe and incubate at 37°C for 30 min; develop color with 3',3-diaminobenzidine until brown, then stop development with tap water; dehydrate by sequentially soaking in gradient alcohols (70%, 80%, 90%, 95%, 100%) for 5 min each; soak in xylene 3 times, 10 min each time; add neutral resin to the tissue area of ​​the section and mount with a coverslip; observe and photograph the section under a microscope.

[0068] The results are as follows Figure 9 As shown, this method constructs an immune probe that can catalyze the oxidation of 3',3-diaminobenzidine by H2O2 to achieve immunohistochemical detection of breast cancer tissue sections. The staining degree of samples with different HER2 overexpression levels shows obvious gradient differences.

[0069] Comparative Example 1

[0070] Preparation of gold-coated silver telluride core-shell nanoclusters using 3-mercaptopropionic acid as a capping agent:

[0071] Under nitrogen protection, 10 μmol of tellurium powder was added to 4 mL of boiling water, followed by 2.5 mmol of sodium borohydride aqueous solution to obtain sodium telluride aqueous solution. Under nitrogen protection, 20 μmol of silver acetate was dissolved in 85 mL of pure water; the reaction system was adjusted to pH 10 with 1 M sodium hydroxide aqueous solution; under high-speed stirring, 1 mmol of 3-mercaptopropionic acid aqueous solution and the above sodium telluride aqueous solution were added, and the reaction was carried out at 60 °C for 80 min; 0.625 μmol of chloroauric acid aqueous solution was added separately, and the reaction was carried out for 30 min; the mixture was cooled to room temperature and stored at 4 °C protected from light.

[0072] like Figure 12 As shown, the product prepared in Comparative Example 1 agglomerated and did not form a product with a good morphology.

[0073] Comparative Example 2

[0074] Preparation of gold-coated silver telluride core-shell nanoclusters with thioglycolic acid as the capping agent:

[0075] Under nitrogen protection, 10 μmol of tellurium powder was added to 4 mL of boiling water, followed by 2.5 mmol of sodium borohydride aqueous solution to obtain an aqueous sodium telluride solution. Under nitrogen protection, 20 μmol of silver acetate was dissolved in 85 mL of pure water, and the pH of the reaction system was adjusted to 10 with 1 M sodium hydroxide aqueous solution. While stirring, 1 mmol of thioglycolic acid aqueous solution was added to the sodium telluride aqueous solution, and the reaction was carried out at 60 °C for 80 min. Then, 0.625 μmol of chloroauric acid aqueous solution was added to the resulting solution, and the reaction was carried out for 30 min. After the reaction was completed, the solution was cooled to room temperature and stored at 4 °C protected from light.

[0076] like Figure 12 As shown, the product prepared in Comparative Example 2 agglomerated and did not form a product with a good morphology.

Claims

1. A method for preparing gold-coated silver telluride core-shell structured nanomaterials, characterized in that, Includes the following steps: The pH of the deoxygenated water-soluble silver source solution was adjusted to 8-11.

5. An aqueous solution of the deoxygenated capping agent and a deoxygenated water-soluble tellurium source solution were added. The reaction was carried out at 60±5℃ for 80±10 min. Then, a deoxygenated water-soluble gold source solution was added to the reaction system. After the reaction was complete, the system was adjusted to room temperature to obtain gold-coated silver telluride core-shell nanomaterial Au@Ag2Te. The capping agent was bovine serum albumin (BSA), guanidine hydrochloride-denatured BSA, tris(2-carbonylethyl) phosphate hydrochloride-denatured BSA, or a combination of guanidine hydrochloride and tris(2-carbonylethyl) phosphate hydrochloride-denatured BSA. The water-soluble silver source was silver acetate, silver nitrate, or silver lactate, and the water-soluble tellurium source was sodium telluride or tellurium. Sodium hydride, with chloroauric acid as the water-soluble gold source; the preparation methods of the guanidine hydrochloride-denatured BSA, tris(2-carbonylethyl)phosphohydrochloride-denatured BSA, and guanidine hydrochloride and tris(2-carbonylethyl)phosphohydrochloride-double-denatured BSA are as follows: under an ice-water bath, guanidine hydrochloride, tris(2-carbonylethyl)phosphohydrochloride, or guanidine hydrochloride and tris(2-carbonylethyl)phosphohydrochloride, are mixed with bovine serum albumin BSA and stirred to obtain denatured BSA; using a capping agent as a reducing agent and stabilizer, the tellurium source and silver source react to generate capping agent-modified silver telluride nanoparticles, and the remaining capping agent continues to reduce the high-valence gold to elemental form and grow on the silver telluride core to form a gold-coated silver telluride core-shell structure.

2. The preparation method according to claim 1, characterized in that, The pH of the reaction system is adjusted to 8-11.5 using an alkaline solution, which can be selected from sodium hydroxide solution, sodium carbonate solution, potassium hydroxide solution, potassium carbonate solution, or ammonia solution.

3. The preparation method according to claim 1, characterized in that, When the capping agent is bovine serum albumin, guanidine hydrochloride-denatured BSA, tris(2-carbonylethyl)phosphohydrochloride-denatured BSA, or guanidine hydrochloride and tris(2-carbonylethyl)phosphohydrochloride-double-denatured BSA, the reaction temperature after adding the deoxygenated water-soluble gold source solution is 0-50℃, and the molar ratio of water-soluble silver source to water-soluble gold source is 2-16:

1.

4. Gold-coated silver telluride core-shell structured nanomaterials prepared by any one of the preparation methods according to claims 1 to 3.

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