Preparation of an artificial enzyme with high H2O2 affinity and its application in a visualization kit

Abstract

The application discloses a preparation of an artificial enzyme with high H2O2 affinity and application thereof in a visualized kit, and comprises the following steps: first, preparing a gold nanorod solution; then, preparing dumbbell-shaped gold nanorod@cerium dioxide; finally, adding a K2PtCl4 solution and irradiating with a near-infrared laser to obtain the artificial enzyme gold nanorod@cerium dioxide@platinum with high H2O2 affinity. Based on the laser-mediated growth method, the heat electron production of plasmonic nanomaterials can be quickly excited under the irradiation of the near-infrared laser, and the rapid reduction and deposition growth of the metal precursor can be realized. The growth morphology and electron distribution of the metal shell layer are controlled by slowing down the heat electron excitation, the substrate binding capacity is improved, and finally the catalytic performance is improved. In addition, the high-performance nanoprobes can be used for constructing a high-sensitivity detection kit, and have great development potential in the field of clinical diagnosis.

Description

Technical Field

[0001] This invention belongs to the fields of nanomaterials science and detection technology, and relates to the preparation of an artificial enzyme with high H2O2 affinity and its application in a visualization kit. In particular, it relates to a method for preparing an artificial enzyme with ultra-high H2O2 affinity, gold nanorods@cerium dioxide@platinum, and the construction of an in vitro diagnostic visualization kit. Background Technology

[0002] To construct nanoreactors with high stability and high detection performance, signal amplification units are an important research target. Finding a nanoprobe with effective cascaded signal amplification holds promise for realizing this vision. As is well known, the mysterious biological systems in nature have always been a source of inspiration for scientific research design. Natural enzymes are a class of biocatalysts with excellent catalytic capabilities, participating in various chemical reactions occurring in living systems. However, the development and application of natural enzymes are limited by their high manufacturing costs and stringent storage conditions. Finding and developing structurally stable alternative materials holds promise for overcoming this obstacle. Since Yan Xiyun's team discovered the enzyme-like effect of Fe3O4 nanoparticles in 2007, the concept of artificially simulated enzymes has emerged, gradually revealing the biocatalytic activity inherent in inorganic nanomaterials. Related research reports propose designing enzyme-simulating systems based on the structure-function relationship of natural enzymes. With the continuous deepening of research on artificially simulated enzymes, their catalytic types are constantly expanding, and their catalytic activity is continuously improving, leading to their widespread application in the biomedical field, including in vitro diagnostics, tumor treatment, antibacterial therapy, anti-inflammatory and antioxidant effects. More importantly, compared with natural enzymes, artificial enzymes have advantages such as higher stability, tunable catalytic activity, and lower storage requirements. Among these advantages, the excellent chemical and structural stability and tunable catalytic activity of artificial enzymes facilitate the design and development of highly stable and high-performance nano-reagent kits, overcoming the inherent limitations of traditional ELISA methods.

[0003] H2O2 is the activator in ELISA kits and a crucial component in constructing numerous detection reactions. However, most artificial enzyme mimics constructed to date exhibit low substrate affinity, which limits their catalytic performance and consequently reduces detection efficiency. Therefore, designing and developing an artificial enzyme mimic probe with high H2O2 affinity would be more beneficial for the effective amplification of cascade catalytic signals and significantly improve kit performance. Summary of the Invention

[0004] The first objective of this invention is to address the shortcomings of existing technologies by providing a method for preparing artificial enzyme-mimicking gold nanorods@cerium dioxide@platinum with high H2O2 affinity. This method induces the growth of a discontinuous shell of fine island-like particles by introducing semiconductors and generating rapid electron transfer between plasma nanoparticles, thereby increasing the specific surface area and the number of catalytic sites. Furthermore, the electron-rich high-defect surface and the electronic synergy between the metals combine to exhibit a high binding capacity between the surface and the substrate, thus significantly improving the affinity.

[0005] The present invention adopts the following technical solution:

[0006] Step (1): Mix chloroauric acid solution, silver nitrate solution, hydroquinone solution, hexadecyltrimethylammonium bromide solution, and sodium borohydride solution to prepare gold nanorod solution;

[0007] Step (2): Add hexadecyltrimethylammonium bromide solution, potassium chloroplatinate solution and cerium acetate solution to the gold nanorod solution to prepare dumbbell-shaped gold nanorods@cerium dioxide;

[0008] Step (3): Add K2PtCl4 solution to gold nanorods@cerium dioxide to obtain a mixed solution, and then irradiate the mixed solution with a near-infrared laser to induce Pt2Pt2PtCl4 reaction. 2+ Restore Pt 0 A Pt shell was deposited and grown on the surface of gold nanorods@cerium dioxide to obtain the artificial enzyme gold nanorods@cerium dioxide@platinum with high H2O2 affinity.

[0009] This invention utilizes a near-infrared laser-mediated growth method to prepare an artificial enzyme with ultra-high H₂O₂ affinity without the addition of surfactants during Pt layer growth. This characteristic significantly enhances its catalytic performance, making it suitable for constructing high-performance in vitro diagnostic kits. Specifically, near-infrared laser-induced hot electron excitation of plasma nanomaterials reduces precursor metal ions and deposits a shell containing catalytically active sites. However, the addition of semiconductor materials causes hot electron transfer, slowing down the reduction deposition growth and resulting in the formation of a textured, island-like structure. The large specific surface area of ​​the shell provides more catalytic sites, and its electronic structure changes, enhancing substrate binding capacity and ultimately leading to a significant improvement in catalytic performance.

[0010] In step (1), the gold nanorods can be prepared by seed-mediated growth method.

[0011] In step (1), firstly, fresh sodium borohydride was prepared by adding ice water to a solution of hexadecyltrimethylammonium bromide and chloroauric acid to obtain a seed solution. Secondly, hydroquinone solution was added to a solution of hexadecyltrimethylammonium bromide, chloroauric acid, and silver nitrate, causing the color to change from yellow to colorless, thus obtaining a growth solution. Finally, a certain amount of seed solution was added to the growth solution for several hours to grow gold nanorods.

[0012] Preferably, in step (1), the concentration of hexadecyltrimethylammonium bromide solution is 0.05-0.15M, the concentration of chloroauric acid solution is 5-15mM, the concentration of sodium borohydride solution is 5-15mM, the concentration of hexadecyltrimethylammonium bromide solution is 0.05-0.15M, the concentration of silver nitrate solution is 5-15mM, and the concentration of hydroquinone solution is 0.05-0.15M.

[0013] Preferably, the volume ratio of each solution in the growth medium is 80:4:1:4. The final volume ratio of seed solution to growth medium is 2:425.

[0014] In step (2), the cerium dioxide growth step is as follows: after centrifuging the gold nanorods twice and concentrating them by 4 times, hexadecyltrimethylammonium bromide surfactant is added, then potassium chloroplatinate solution is added for the growth and positioning of cerium dioxide, and finally cerium acetate solution is added as the precursor material of cerium dioxide. The mixture is kept in an oven at 90-120℃ for 0.7-1.5h to finally obtain gold nanorods@cerium dioxide (dumbbell shape).

[0015] Preferably, in step (2), the concentration of the hexadecyltrimethylammonium bromide solution is 0.05-0.15 M; the concentration of the potassium chloroplatinate solution is 0.05-0.15 mM; and the concentration of the cerium acetate solution is 5-15 mM. The volume ratio of the hexadecyltrimethylammonium bromide solution, the potassium chloroplatinate solution, and the cerium acetate solution is 3:1:(1.5-2), more preferably 3:1:1.5.

[0016] In step (3), the Pt shell is composed of fine, uneven, island-like particles, which are deposited and grown on both sides of the gold nanorods. Under near-infrared laser irradiation, Pt... 2+ It will be reduced to Pt by the excited hot electrons. 0 They gradually deposit and grow. Unlike gold nanorods, the addition of cerium dioxide causes hot electron transfer, which slows down the reduction process, makes the growth discontinuous, and leads to significant changes in morphology and structure.

[0017] Preferably, in step (3), the wavelength of the near-infrared laser is 808 nm, and the irradiation time is 50-100 min. The laser emitter should be positioned perpendicular to the tabletop, preferably at a distance of 7.5 cm, and the solution should be directly below the light source.

[0018] Preferably, in step (3), the concentration of the K2PtCl4 solution is 50-150 mM; Pt 2+ The solution needs to be stirred evenly after being added.

[0019] The second objective of this invention is to provide an artificial enzyme-mimicking gold nanorod@cerium dioxide@platinum with high H2O2 affinity, prepared using the above method. This artificial enzyme-mimicking probe significantly improves catalytic performance in terms of material composition, structure, and electron transfer characteristics. Reagent kits constructed based on this artificial enzyme-mimicking probe have advantages such as high detection sensitivity, stable detection, and good reproducibility, and can be applied in the field of clinical diagnosis.

[0020] In the artificial enzyme gold nanorod@cerium dioxide@platinum with high H2O2 affinity, the gold nanorod serves as an electronic excitation element, capable of receiving laser-driven plasma thermal and hot electron excitation in the near-infrared region; cerium dioxide serves as an electron transfer receiving element, its semiconductor structure capable of receiving electron transfer; platinum serves as a catalytic performance regulating element, providing catalytic sites; the structure of the artificial enzyme gold nanorod@cerium dioxide@platinum with high H2O2 affinity is dumbbell-shaped, wherein the two ends of the dumbbell shape are multi-layered stacked flower-like cerium dioxide, the middle connecting part is the gold nanorod, and the outer side of the gold nanorod is covered with a convex and undulating small island-like Pt shell.

[0021] A third objective of this invention is to provide the application of the aforementioned artificial enzyme-mimicking gold nanorods@cerium dioxide@platinum with high H2O2 affinity in the preparation of in vitro diagnostic visualization kits.

[0022] The aforementioned artificial enzyme mimicking gold nanorods@cerium dioxide@platinum with ultra-high H2O2 affinity was used as a bio-enzyme marker in traditional in vitro enzyme-linked immunosorbent assay (ELISA) kits, for example, to replace horseradish peroxidase. The role of the bio-enzyme marker is signal amplification, and the artificial enzyme mimicking enzyme also plays this role. However, the artificial enzyme mimicking gold nanorods@cerium dioxide@platinum has a higher affinity for H2O2 than horseradish peroxidase, which significantly improves its catalytic performance, thereby achieving a greater cascade signal amplification effect. Using sarcosine as a detection conceptual model, a kit for detecting sarcosine was constructed with a detection limit of 0.17 μM and applied to the in vitro diagnosis of prostate cancer.

[0023] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0024] (1) This invention utilizes laser-induced growth to synthesize nanomaterials and construct high-performance artificial enzymes. Compared with traditional wet chemical synthesis methods, it does not require the addition of surfactants, making the synthesis more green and convenient. The element doping, shell structure and charge distribution are controlled by plasma-driven hot electron excitation and electron transfer characteristics, which is conducive to the construction of highly sensitive responsive reagent kits.

[0025] (2) This invention utilizes cerium dioxide semiconductor material to induce the transfer of hot electrons, thereby regulating the structure of artificially simulated enzymes, thereby changing their morphology, number of catalytic sites and electronic structure, etc. The comprehensive design strategy improves their affinity for H2O2, thereby significantly enhancing their catalytic performance.

[0026] (3) The high-performance nanoprobe designed in this invention can be used as a general signal amplification element to construct in vitro diagnostic kits, enabling the detection of H2O2 and a series of biomarkers that can generate H2O2, and has great potential for clinical diagnostic applications. Attached Figure Description

[0027] Figure 1 The image shows a TEM image of the Au NR solution prepared in Example 1, with a scale bar of 100 nm.

[0028] Figure 2 The image shows a TEM image of the Au@CeO2 solution prepared in Example 1, with a scale bar of 100 nm.

[0029] Figure 3 The image shows a TEM image of the Au@CeO2@Pt solution prepared in Example 1, with a scale bar of 50 nm.

[0030] Figure 4 The image shows a TEM image of the Au@Pt solution prepared in Comparative Example 1, with a scale bar of 100 nm.

[0031] Figure 5 The image shows a TEM image of the CeO2NP solution prepared in Comparative Example 2, with a scale bar of 100 nm.

[0032] Figure 6 This section presents comparative data on the substrate affinity of AuNR, Au@CeO2, Au@CeO2@Pt prepared in Example 1, Au@Pt prepared in Comparative Example 1, CeO2 NP prepared in Comparative Example 2, and horseradish peroxidase HRP, where K... m is the Michaelis constant; the smaller the value, the higher the affinity of the material for the substrate.

[0033] Figure 7The Au@CeO2@Pt prepared in Example 1 was used to construct a kit and to detect the changes in UV-Vis absorption spectra of different concentrations of sarcosine. In the figure, a is the UV absorption spectrum change of different concentrations of sarcosine; b is the standard curve of sarcosine concentration detection; and c is the color change of different concentrations of sarcosine. Detailed Implementation

[0034] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the invention.

[0035] Example 1

[0036] (1) Synthesis of single surfactant gold nanorods (AuNR)

[0037] Seed culture: Add 0.3645 g of hexadecyltrimethylammonium bromide (CTAB) and 10 mL of water to a 20 mL glass bottle, and stir to dissolve in a 50 °C water bath to obtain a 0.1 M CTAB solution. Then, stir slowly at room temperature and add 0.25 mL of 10 mM HAuCl4. After stirring until well mixed, add 0.6 mL of fresh NaBH4 solution prepared with ice water while stirring rapidly, stop stirring after 2 min, and let stand in a 30 °C water bath for 2 h.

[0038] Growth solution: Add 13.85 g CTAB and 380 mL of water to a 500 mL three-necked flask, and stir in a 50 °C water bath until completely transparent to obtain a 0.1 M CTAB solution. Then continue stirring in a 30 °C water bath until the temperature stabilizes, and add 5 mL of 10 mM MgNO3, 20 mL of 10 mM HAuCl4, and 20 mL of freshly prepared 0.1 M hydroquinone.

[0039] Growth procedure: Finally, add 2 mL of the completed seed culture, stir for 30 seconds, and then let it stand in a 30℃ water bath for at least 6 hours. After growth, first centrifuge at 8000 rpm for 10 minutes and wash with water, then centrifuge at 7000 rpm for 10 minutes and wash with water again. During the entire centrifugation process to remove the supernatant, free CTAB should be removed as much as possible. Finally, all precipitates are collected and dispersed with water to 100 mL.

[0040] Figure 1 This is a TEM image of the Au NR obtained in this embodiment. The Au NR is in the shape of a long rod.

[0041] (2) Au@CeO2 (dumbbell type)

[0042] Take 20 mL of the concentrated Au NRs synthesized according to scheme (1) above and place it in a 100 mL beaker. Then add 6 mL of 1 mM CTAB and 24 mL of water, mix gently, and let stand in a 30 °C water bath for 5 min. Then add 1 mL of 0.2 mM K2PtCl4 and shake gently, and let stand in a 30 °C water bath for 5 min. Then add 4 mL of 10 mM Ce(Ac)3 and 44 mL of water, shake gently, and let stand in a 100 °C oven for 2 h. After growth is complete, centrifuge at 7000 rpm for 10 min, and disperse the precipitate with water for later use.

[0043] Figure 2 This is a TEM image of Au@CeO2 obtained in this embodiment. Au@CeO2 exhibits a dumbbell shape and has smooth sides.

[0044] (3) Au@CeO2@Pt (laser-induced growth method)

[0045] Take 10 mL of the Au@CeO2 solution from (2) into a 20 mL glass bottle, then add 200 μL of 0.15 Mk2PtCl4 solution and shake gently. Irradiate the solution under an 808 nm laser for 50 min (laser power 90%, light source height 7.5 cm). After growth, disperse the solution by ultrasonication, and the solution color changes from purplish-red to black. Then, bring the solution to a final volume of 5 mL, centrifuge at 5000 rpm for 5 min, and wash once with water.

[0046] Figure 3 The image shows a TEM image of Au@CeO2@Pt obtained in this embodiment. Au@CeO2@Pt exhibits a dumbbell shape and has a rough side with small, uneven, island-like particles.

[0047] Figure 6 The K of the Au@CeO2@Pt solution prepared in this embodiment m The value was 0.26 mM, higher than HRP (3.7 mM) and Au@Pt (0.67 mM), demonstrating that laser-induced growth based on electron transfer can maximize substrate affinity.

[0048] Example 2

[0049] (1) Synthesis of single surfactant gold nanorods (AuNRs)

[0050] Seed culture: Add 0.4738 g of hexadecyltrimethylammonium bromide (CTAB) and 10 mL of water to a 20 mL glass bottle, and stir to dissolve in a 50 °C water bath to obtain a 0.13 M CTAB solution. Then, stir slowly at room temperature and add 0.25 mL of 13 mM HAuCl4. After stirring until well mixed, add 0.8 mL of fresh NaBH4 solution prepared with ice water while stirring rapidly, stop stirring after 2 min, and let stand in a 30 °C water bath for 2 h.

[0051] Growth medium: Add 18g CTAB and 380mL water to a 500mL three-necked flask, and stir in a 50℃ water bath until completely transparent to obtain a 0.13M CTAB solution. Then continue stirring in a 30℃ water bath until the temperature stabilizes, and add 5mL of 13mM MgNO3, 20mL of 13mM HAuCl4, and 20mL of freshly prepared 0.13M hydroquinone.

[0052] Growth procedure: Finally, add 2 mL of the completed seed culture, stir for 30 seconds, and then let it stand in a 30℃ water bath for at least 6 hours. After growth, first centrifuge at 8000 rpm for 10 minutes and wash with water, then centrifuge at 7000 rpm for 10 minutes and wash with water again. During the entire centrifugation process to remove the supernatant, free CTAB should be removed as much as possible. Finally, all precipitates are collected and dispersed with water to 100 mL.

[0053] (2) Au@CeO2 (dumbbell type)

[0054] Take 20 mL of the concentrated Au NRs synthesized according to scheme (1) above and place it in a 100 mL beaker. Then add 6 mL of 1 mM CTAB and 24 mL of water, mix gently, and let stand in a 30 °C water bath for 5 min. Then add 1 mL of 0.2 mM K2PtCl4 and shake gently, and let stand in a 30 °C water bath for 5 min. Then add 4 mL of 10 mM Ce(Ac)3 and 44 mL of water, shake gently, and let stand in a 100 °C oven for 2 h. After growth is complete, centrifuge at 7000 rpm for 10 min, and disperse the precipitate with water for later use.

[0055] (3) Au@CeO2@Pt (laser-induced growth method)

[0056] Take 10 mL of the Au@CeO2 solution from (2) into a 20 mL glass bottle, then add 200 μL of 0.15 Mk2PtCl4 solution and shake gently. Irradiate the solution under an 808 nm laser for 50 min (laser power 90%, light source height 7.5 cm). After growth, disperse the solution by ultrasonication, and the solution color changes from purplish-red to black. Then, bring the solution to a final volume of 5 mL, centrifuge at 5000 rpm for 5 min, and wash once with water.

[0057] Comparative Example 1: Without the addition of cerium dioxide, Pt was directly induced to grow using gold rods.

[0058] By replacing the growth material in step (3) of Example 1 above, that is, replacing Au@CeO2 with AuNR, laser-mediated growth of Au@Pt particles can be obtained. Other steps and parameters are the same.

[0059] Take 10 mL of Au NR solution into a 20 mL glass bottle, then add 200 μL of 0.15 M K₂PtCl₄ solution and gently shake well. Irradiate the solution under an 808 nm laser for 50 min (laser power 90%, light source height 7.5 cm). After growth, disperse the solution by ultrasonication, and the solution color changes from purplish-red to black. Then, bring the solution to a final volume of 5 mL, centrifuge at 5000 rpm for 5 min, and wash once with water.

[0060] Figure 4 This is a TEM image of the Au@Pt solution prepared in this embodiment. Au@Pt exhibits a core-shell structure. Figure 6 The K of the Au@Pt solution prepared in this embodiment m The value was 0.67 mM, which is higher than that of horseradish peroxidase (HRP) (3.7 mM), proving that laser-induced growth method is beneficial to improve substrate affinity.

[0061] Comparative Example 2: No gold nanorods added

[0062] By replacing AuNRs with water in step (2) of Example 1 above, the new material cerium dioxide nanoparticles (CeO2 NP) can be obtained. All other steps and parameters are the same.

[0063] Place 20 mL of water in a 100 mL beaker, then add 6 mL of 1 mM CTAB and 24 mL of water. Mix gently and let stand in a 30°C water bath for 5 min. Next, add 1 mL of 0.2 mM K₂PtCl₄ and gently shake, then let stand in a 30°C water bath for 5 min. Then add 4 mL of 10 mM Ce(Ac)₃ and 44 mL of water, gently shake, and let stand in a 100°C oven for 2 h. After growth, centrifuge at 7000 rpm for 10 min, and disperse the precipitate with water for later use.

[0064] Figure 5 This is a TEM image of the CeO2 NP solution prepared in this embodiment. The CeO2 NP exhibits an aggregated flower-like structure formed by the stacking of multiple particles. Figure 6 The K of the CeO2 NP solution prepared in this embodiment m The value was 24.66 mM, which is lower than HRP (3.7 mM).

[0065] Comparative Example 3: Au NR

[0066] The synthesis method is the same as step (1) of Example 1 above, and the steps and parameters are the same.

[0067] Figure 6 The K of the Au NR solution prepared in this embodiment m The value was 196.11 mM, which is lower than HRP (3.7 mM).

[0068] Comparative Example 4: Au@CeO2

[0069] The synthesis method is the same as step (2) of Example 1 above, with the same steps and parameters.

[0070] Figure 6 The K of the Au@CeO2 solution prepared in this embodiment m The value is 15.26 mM, lower than HRP (3.7 mM). Application Example 1:

[0071] The Au@CeO2 prepared in Example 1 was used to construct a kit and to detect different concentrations of creatine. The specific steps are as follows:

[0072] Detection protocol: First, add 10 μL of creatine at different concentrations (0.5, 1, 5, 10, 20, 30, 40, 50, 70, 100) and 10 μL of SOx (1 mg / mL) to a 0.5 mL centrifuge tube and incubate at 37 °C for 10 min. Then add 70 μL of HAc-NaAc buffer (pH 4.5), 10 μL of TMB (10 mM), 10 μL of Au@CeO2@Pt, and 100 μL of deionized water, mix thoroughly, and react at 37 °C for 10 min. After terminating the reaction, measure the UV spectrum of the final solution and take a color photograph of the solution using a smartphone.

[0073] Figure 7 The test results. (By...) Figure 7 It can be seen that as the concentration of the target analyte sarcosine increases, its absorbance value also increases, showing a positive correlation. The relationship between the target analyte concentration and the output signal verifies the detection performance of the kit of the present invention. That is, the present invention provides a high-performance artificial enzyme Au@CeO2@Pt that can be used to detect sarcosine, with a detection limit of 0.17 μM, and can be further applied to the in vitro diagnosis of prostate cancer.

Claims

1. A method for preparing artificial enzyme-mimicking gold nanorods@cerium dioxide@platinum with high H2O2 affinity, characterized in that, The method includes the following steps: Step (1): Mix chloroauric acid solution, silver nitrate solution, hydroquinone solution, hexadecyltrimethylammonium bromide solution, and sodium borohydride solution to prepare gold nanorod solution; Step (2): Add hexadecyltrimethylammonium bromide solution, potassium chloroplatinate solution and cerium acetate solution to the gold nanorod solution to prepare dumbbell-shaped gold nanorods@cerium dioxide. Step (3): Add K2PtCl4 solution to gold nanorods@cerium dioxide to obtain a mixed solution. No surfactant needs to be added. Then, irradiate the mixed solution with a near-infrared laser with a wavelength of 808 nm for 50-100 min to induce Pt-induced polarization. 2+ Restore Pt 0 A Pt shell was deposited and grown on the surface of gold nanorods@cerium dioxide to obtain the artificial enzyme gold nanorods@cerium dioxide@platinum with high H2O2 affinity. The structure of the artificial enzyme gold nanorods@cerium dioxide@platinum with high H2O2 affinity is dumbbell-shaped, wherein the two ends of the dumbbell shape are multi-layered stacked flower-shaped cerium dioxide, the middle connecting part is a gold nanorod, and the outside of the gold nanorod is covered with an undulating island-shaped Pt shell.

2. The preparation method according to claim 1, characterized in that, In step (1), the concentration of the cetyltrimethylammonium bromide solution is 0.05-0.15 M, the concentration of the chloroauric acid solution is 5-15 mM, the concentration of the sodium borohydride solution is 5-15 mM, the concentration of the silver nitrate solution is 5-15 mM, and the concentration of the hydroquinone solution is 0.05-0.15 M.

3. The preparation method according to claim 1, characterized in that, In step (2), the reaction temperature is 90-120 ℃ and the reaction time is 0.7-1.5 h.

4. The preparation method according to claim 1, characterized in that, In step (2), the concentration of hexadecyltrimethylammonium bromide solution is 0.05-0.15 M; the concentration of potassium chloroplatinate solution is 0.05-0.15 mM; and the concentration of cerium acetate solution is 5-15 mM.

5. The preparation method according to claim 4, characterized in that, In step (2), the volume ratio of hexadecyltrimethylammonium bromide solution, potassium chloroplatinate solution and cerium acetate solution is 3:1:(1.5-2).

6. The preparation method according to claim 1, characterized in that, In step (3), the concentration of the K2PtCl4 solution is 50-150 mM.

7. A gold nanorod@cerium dioxide@platinum with high H2O2 affinity for an artificial enzyme, characterized in that, It is prepared by the method described in any one of claims 1-6.

8. The application of the artificial enzyme-mimicking gold nanorods@cerium dioxide@platinum with high H2O2 affinity as described in claim 7 in the preparation of an in vitro diagnostic visualization kit.

Images