PtNP-Tn Nanozyme and Its Preparation Method and Application, Detection Kit and Application of Detection Kit

Abstract

The present invention discloses a PtNP-Tn nanozyme and its preparation method and application, a detection kit and the application of the detection kit. The PtNP-Tn nanozyme is synthesized by using H2PtCl6 as a precursor under the mediation of a polyT template. The preparation method is as follows: after mixing H2PtCl6 and polyT, oscillate and incubate; add NaBH4 to the reaction system to obtain the PtNP-Tn nanozyme. The detection kit includes the PtNP-Tn nanozyme, an acetic acid buffer solution containing H2O2 and 3,3',5,5'-tetramethylbenzidine. The present invention uses the DNA sequence Tn to mediate the formation of the nanozyme, significantly improving the catalytic activity of the nanozyme and effectively enhancing the stability of the nanozyme at high temperature, freezing, and long-term storage. Antimony(III) significantly inhibits the catalytic activity of the PtNP-Tn nanozyme and can be used to detect antimony(III) in water quality samples.

Description

Technical Field

[0001] The present invention relates to the technical field of biosensors, and in particular to a PtNP-Tn nanozyme and a preparation method and application thereof, a detection kit and an application of the detection kit. Background Art

[0002] With the development of science and technology, antimony has been widely used in the production of various flame retardants, alloys, ceramics, glass, pigments, semiconductor components, medicines and chemicals. As a result, large amounts of waste gas, wastewater and waste residues containing antimony or its compounds are discharged, which will inevitably lead to increasing environmental pollution. Workers who are exposed to antimony-containing environments for a long time will have certain threats to their health, such as damage to multiple tissues and organs such as skin mucosa, heart, liver, lungs and nervous system. In addition, studies have shown that the toxicity of antimony has a certain relationship with its form of existence, among which the toxicity of trivalent antimony is much higher than that of pentavalent antimony. Therefore, the specific monitoring of trivalent antimony (antimony (III)) in the environment is of great significance for environmental protection and life safety.

[0003] At present, the main methods for detecting antimony include inductively coupled plasma mass spectrometry, inductively coupled plasma emission spectroscopy, hydride atomic fluorescence, hydride atomic absorption spectrophotometry, etc. These methods have high sensitivity, high accuracy, and strong specificity, but usually require expensive large equipment and professional operators, and cannot meet the needs of fast and low-cost portable detection. Therefore, it is very necessary to build a simple-to-operate, portable sensing platform for the detection of antimony (III).

[0004] Based on this, the art needs to seek a method with high stability, simple and mild preparation conditions, low preparation cost, and the ability to achieve high sensitivity and high specificity detection of antimony (III). Summary of the invention

[0005] In view of the above-mentioned technical problems that need to be solved, the present invention provides a PtNP-Tn nanozyme and a preparation method and application thereof, a detection kit and an application of the detection kit. The PtNP-Tn nanozyme has strong catalytic activity, high stability, simple and mild preparation conditions, low preparation cost, and can achieve high-sensitivity and high-specificity detection of antimony (III).

[0006] In order to achieve the above-mentioned object, the present invention provides a PtNP-Tn nanozyme. The PtNP-Tn nanozyme uses H2PtCl6 as a precursor and synthesizes the PtNP-Tn nanozyme under the mediation of a polyT template.

[0007] The above-mentioned PtNP-Tn nanozyme, further, the above-mentioned polyT is one of T5, T10, T15, and T20;

[0008] The DNA sequence of the above T5 is: 5'-TTTTT-3';

[0009] The DNA sequence of the above T10 is: 5'-TTTTTTTTTT-3';

[0010] The DNA sequence of the above T15 is: 5'-TTTTTTTTTTTTTTT-3';

[0011] The DNA sequence of the above T20 is: 5'-TTTTTTTTTTTTTTTTTTTT-3'.

[0012] Based on a general technical concept, the present invention also provides a method for preparing the above PtNP-Tn nanozyme, and the above preparation method includes the following steps:

[0013] S1. After mixing H2PtCl6 and polyT, incubate with shaking;

[0014] S2. Add NaBH4 to the reaction system, and the color of the solution turns brown to complete the preparation of the PtNP-Tn nanozyme.

[0015] For the above preparation method, further, the molar concentration ratio of the above H2PtCl6 to polyT is 500:1.

[0016] For the above preparation method, further, the conditions for the above incubation with shaking are: incubate with shaking at 25°C to 45°C for 10 min to 30 min.

[0017] Based on a general technical concept, the present invention also provides an application of the above PtNP-Tn nanozyme in detecting trivalent antimony.

[0018] Based on a general technical concept, the present invention also provides a detection kit, including the above PtNP-Tn nanozyme, catalytic substrate solution 1 and catalytic substrate solution 2;

[0019] The components of the above catalytic substrate solution 1 include: an acetic acid buffer solution with pH = 4 containing H2O2;

[0020] The components of the above catalytic substrate solution 2 include: 3,3',5,5'-tetramethylbenzidine.

[0021] For the above detection kit, further, in the catalytic substrate solution 1, the concentration of H2O2 is 1.0 mM, and the concentration of HAc-NaAc is 40 mM.

[0022] For the above detection kit, further, the concentration of 3,3',5,5'-tetramethylbenzidine in the catalytic substrate solution 2 is 1.0 mM.

[0023] Based on a general inventive concept, the present invention also provides an application of the above detection kit in the detection of trivalent antimony.

[0024] For the above application, further, the method of the application is as follows:

[0025] (1) Mix the PtNP-Tn nanozyme with the sample to be tested and incubate to obtain a first mixture;

[0026] (2) Mix the catalytic substrate solution 1 and the catalytic substrate solution 2 evenly according to a molar concentration ratio of 1:1 to obtain a second mixture;

[0027] (3) Mix the first mixture and the second mixture, and measure the absorbance A value at a wavelength of 652 nm by an enzyme-labeling instrument. The concentration of trivalent antimony in the sample to be tested is positively correlated with the value of A0 - A; A0 is the absorbance value at a wavelength of 652 nm when the concentration of trivalent antimony is 0.

[0028] For the above application, further, (1) specifically: the PtNP-Tn nanozyme and the sample to be tested are mixed according to a volume ratio of 4:1 and incubated at room temperature for 20 min.

[0029] For the above application, further, (3) specifically: mix the first mixture and the second mixture according to a volume ratio of 40:1, measure the absorbance A value at a wavelength of 652 nm by an enzyme-labeling instrument. The concentration of trivalent antimony in the sample to be tested is positively correlated with the value of A0 - A; A0 is the absorbance value at a wavelength of 652 nm when the concentration of trivalent antimony is 0.

[0030] Compared with the prior art, the advantages of the present invention are as follows:

[0031] (1) The present invention provides a PtNP-Tn nanozyme. The formation of the nanozyme is mediated by the DNA sequence Tn. The first function of Tn is to act as a protective agent to enhance the stability of the nanozyme; the second is to improve the catalytic activity of the nanozyme. Therefore, the PtNP-Tn nanozyme of the present invention significantly improves the catalytic activity of the nanozyme. More importantly, it effectively improves the stability of the nanozyme at high temperature, freezing, and long-term storage.

[0032] (2) The present invention provides a preparation method of the PtNP-Tn nanozyme. The preparation conditions are simple and mild, and the preparation cost is low, which can be used for industrial production.

[0033] (3) The present invention provides an application of the PtNP-Tn nanozyme in the detection of trivalent antimony. Trivalent antimony significantly inhibits the catalytic activity of the PtNP-Tn nanozyme, and there is a good linear relationship between the inhibition effect and the concentration of trivalent antimony. Based on the inhibitory effect of antimony(III) on the catalytic activity of the PtNP-Tn nanozyme, a simple, rapid, and sensitive colorimetric sensing platform is developed, which can be used to detect antimony(III) in water quality samples. Brief Description of the Drawings

[0034] To make the objectives, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present invention.

[0035] Figure 1 This is the electron microscopy characterization diagram of PtNP-T10 nanozyme and PtNP nanozyme in Example 1 of the present invention.

[0036] Figure 2 This is the kinetic investigation result diagram of the catalytic activities of PtNP-T10 nanozyme and PtNP nanozyme in Example 1 of the present invention.

[0037] Figure 3 This is the catalytic activity investigation result diagram of PtNP-T10 nanozyme and PtNP nanozyme after thermal cycling in Example 1 of the present invention.

[0038] Figure 4 This is the catalytic activity investigation result diagram of PtNP-T10 nanozyme and PtNP nanozyme after freeze-thaw cycling in Example 1 of the present invention.

[0039] Figure 5 This is the stability investigation result diagram of PtNP-T10 nanozyme and PtNP nanozyme during long-term storage in Example 2 of the present invention.

[0040] Figure 6 This is the standard curve regression equation diagram of PtNP-T10 nanozyme for the detection of antimony(III) in Example 2 of the present invention.

[0041] Figure 7 This is the optimized incubation temperature result diagram of PtNP-T10 nanozyme for the detection of antimony(III) in Example 2 of the present invention.

[0042] Figure 8 This is the optimized incubation time result diagram of PtNP-T10 nanozyme for the detection of antimony(III) in Example 2 of the present invention.

[0043] Figure 9 This is the selectivity analysis result diagram of PtNP-T10 nanozyme for the detection of antimony(III) in Example 2 of the present invention.

[0044] Figure 10 This is the influence result diagram of PtNP-Tn nanozyme mediated by different lengths of T-rich DNA sequences on the detection of antimony(III) in Examples 2 to 5 of the present invention. Detailed Embodiments

[0045] The present invention will be further described below in conjunction with specific preferred embodiments, but the protection scope of the present invention is not limited thereby.

[0046] Unless otherwise defined, all professional terms used hereinafter have the same meaning as commonly understood by those skilled in the art. The professional terms used herein are only for the purpose of describing specific embodiments and are not intended to limit the protection scope of the present invention.

[0047] Unless otherwise specifically stated, various raw materials, reagents, instruments, and equipment used in the present invention can be obtained through market purchases or can be prepared by existing methods. The methods in the following examples are conventional methods in the art unless otherwise specified.

[0048] Example

[0049] The materials and instruments used in the following examples are all commercially available.

[0050] Example 1

[0051] A PtNP-T10 nanozyme of the present invention was prepared by the following method:

[0052] (1) 5 μL of H2PtCl6 with a concentration of 10 mM and 10 μL of T10 with a concentration of 10 μM (the nucleotide sequence of T10 is: 5'-TTTTTTTTTT-3'.) were thoroughly mixed in an aqueous solution and incubated with shaking at room temperature for 20 min.

[0053] (2) 8 μL of NaBH4 with a concentration of 20 mM was added to the reaction system, and the mixture was shaken thoroughly. The solution turned brown, indicating that the PtNP-T10 nanozyme was successfully prepared.

[0054] Comparative Example 1

[0055] A PtNP nanozyme of the present invention was prepared by the following method:

[0056] (1) 5 μL of 10 mM H2PtCl6 was thoroughly mixed in an aqueous solution and incubated with shaking at room temperature for 20 min.

[0057] (2) 8 μL of NaBH4 with a concentration of 20 mM was added to the reaction system, and the mixture was shaken thoroughly. The solution turned brown, indicating that the PtNP nanozyme was successfully prepared.

[0058] Experiment 1: The morphology and size of the PtNP-T10 nanozyme and the PtNP nanozyme were characterized by transmission electron microscopy (TEM).

[0059] Figure 1In Example 1 of the present invention, the electron microscopy characterization diagrams of PtNP-T10 nanozyme and PtNP nanozyme are shown. It can be seen from the figures that the particle size of the synthesized PTNP-T10 nanozyme is 50.1±14.2 nm, presenting a cluster shape. The particle size of the synthesized PTNP nanozyme is 5.2±0.7 nm.

[0060] Experiment 2: Investigate the affinity between PtNP-T10 nanozyme, PtNP nanozyme and the substrate.

[0061] 5 μL of PtNP-T10 nanozyme and PtNP nanozyme were respectively added to the acetate buffer solution (pH = 4) containing different concentrations of 3,3',5,5'-tetramethylbenzidine (TMB) and 0.5 mM H2O2. The change curve of the absorbance at 652 nm with time was measured by a UV-visible spectrophotometer using the kinetic scanning mode to track the catalytic oxidation of TMB. According to the Lambert-Beer law, the concentration of the product oxidized TMB (oxTMB) can be calculated. The reaction rate conforms to the Michaelis Menten equation: v = Vmax×([S]) / ([S]+K M ), K M value is the Michaelis constant, which reflects the binding affinity between the enzyme and the substrate. Vmax represents the reaction rate when the substrate concentration is saturated, and [S] refers to the substrate concentration.

[0062] Figure 2 In Example 1 of the present invention, the kinetic investigation of the catalytic activities of PtNP-T10 nanozyme and PtNP nanozyme was carried out. The change curve of the UV absorbance at 652 nm with time at different substrate concentrations was investigated by a UV-visible spectrophotometer, and the Michaelis binding constant of enzyme catalysis was obtained by fitting calculation. The Michaelis constant K M value of PtNP-T10 nanozyme was 0.0247 mM, and the Michaelis constant K M value of PtNP nanozyme was 0.0889 mM, indicating that PtNP-T10 nanozyme has a higher affinity with the catalytic substrate TMB.

[0063] Experiment 3: Investigate the stability of the catalytic activities of PtNP-T10 and PtNP nanozymes.

[0064] Thermal cycling: The PtNP-T10 nanozyme and the PtNP nanozyme were subjected to multiple thermal cycles at 80 °C respectively. Then, the PtNP-T10 nanozyme and the PtNP nanozyme treated by thermal cycling were placed at room temperature, and then added to a catalytic substrate solution containing 0.5 mM TMB, 0.5 mM H2O2 and 20 mM HAc-NaAc buffer (pH 4.0), and the catalytic reaction was carried out at 25 °C for 10 minutes. The absorbance at 652 nm was measured by a microplate reader to represent the catalytic performance of the nanozyme.

[0065] Cold cycling: The PtNP-T10 nanozyme and the PtNP nanozyme were subjected to cold cycling at -20 °C respectively. Then, the PtNP-T10 nanozyme and the PtNP nanozyme treated by freeze-thaw were placed at room temperature, and then added to a catalytic substrate solution containing 0.5 mM TMB, 0.5 mM H2O2 and 20 mM HAc-NaAc buffer (pH 4.0), and the catalytic reaction was carried out at 25 °C for 10 minutes. The absorbance at 652 nm was measured by a microplate reader to represent the catalytic performance of the nanozyme.

[0066] Figure 3 This is for the investigation and comparison of the catalytic activities of the PtNP-T10 nanozyme and the PtNP nanozyme after thermal cycling in Example 1 of the present invention; Figure 4 This is for the investigation and comparison of the catalytic activities of the PtNP-T10 nanozyme and the PtNP nanozyme after freeze-thaw cycling in Example 1 of the present invention.

[0067] As can be seen from the results in the figure, the PtNP-T10 nanozyme can maintain more than 80% of its original catalytic activity after five freeze-thaw cycles or five thermal cycles, while the PtNP nanozyme basically loses its catalytic activity after only one freeze-thaw cycle or thermal cycle. Therefore, it shows that the PtNP-T10 nanozyme has significantly better heat and cold resistance than the PtNP nanozyme.

[0068] Figure 5 This is the result of the investigation on the stability of the PtNP-T10 nanozyme during long-term storage in Example 1 of the present invention. As can be seen from the figure: The PtNP-T10 nanozyme still maintains its original catalytic activity unchanged after being stored for up to 30 days, while during the storage process of the PtNP nanozyme, its catalytic activity gradually decreases and basically loses its horseradish peroxidase-like catalytic activity after being stored for 5 days. This proves that the PtNP-T10 nanozyme also has significantly better stability than the PtNP nanozyme during long-term storage.

[0069] Example 2:

[0070] A kit for detecting antimony (III) based on the regulation of the catalytic activity of PtNP by T base sequence, comprising a PtNP-Tn nanozyme, a catalytic substrate solution 1 and a catalytic substrate solution 2;

[0071] The composition of catalytic substrate solution 1 is an acetic acid buffer solution with pH = 4 containing H2O2, and the composition of catalytic substrate solution 2 is TMB.

[0072] An application of the kit of this embodiment in detecting antimony(III), and the application method includes the following steps:

[0073] (1) Add a sample containing gradient concentrations of antimony(III) to the nanozyme PtNP-T10 and incubate at room temperature.

[0074] (2) Subsequently, add the incubated solution to the mixed solution of catalytic substrate solution 1 and catalytic substrate solution 2 (in the mixed solution, the concentration of H2O2 is 0.5 mM, the concentration of HAc-NaAc is 20 mM, and the concentration of TMB is 0.5 mM). After reacting for a period of time, measure the absorbance value A at a wavelength of 652 nm of the obtained solution with an enzyme-labeled instrument.

[0075] (3) By measuring the absorbance value A at a wavelength of 652 nm corresponding to a series of antimony(III) concentrations, and taking the absorbance value A0 at a wavelength of 652 nm corresponding to the sample with antimony(III) concentration of 0, as the antimony(III) concentration increases, the absorbance difference A0 - A at a wavelength of 652 nm gradually increases, and its correlation can be obtained by fitting. The specific steps are as follows:

[0076] Add samples containing different concentrations of antimony(III) to the PtNP-T10 nanozyme and incubate at 25 °C for 30 min; subsequently, add the incubated solution to the catalytic substrate solution containing 0.5 mM TMB, 0.5 mM H2O2 and 20 mM HAc-NaAc buffer solution (pH 4.0), and catalyze the reaction at 25 °C for 10 minutes. Measure the absorbance value A at a wavelength of 652 nm of the reaction system with an enzyme-labeled instrument; the absorbance value A0 at a wavelength of 652 nm corresponding to the sample with antimony(III) concentration of 0, as the antimony(III) concentration increases, the value of A0 - A gradually increases. Figure 6 It is the regression equation graph of the standard curve.

[0077] In the figure, a standard curve is plotted with the concentration of antimony(III) as the abscissa and (A0 - A) as the ordinate. The regression equation of the standard curve: y = 0.0070X + 0.054, the correlation coefficient R 2 = 0.9979, and the detection limit is 2.28 μg / L. Among them, y is A0 - A, x is the concentration of antimony(III), and the unit is μg / L.

[0078] (4) For the antimony(III) solution to be measured, measure the absorbance value A at a wavelength of 652 nm with an enzyme-labeled instrument, substitute the A value into the regression equation of the standard curve, and obtain the concentration of the antimony(III) solution to be measured.

[0079] Experiment 4: To investigate the effect of the incubation of antimony(III) with PtNP-T10 nanozyme at different temperatures on its detection.

[0080] Three temperature conditions of 25 °C, 35 °C, and 45 °C were selected for investigation. The experimental results showed that when the incubation temperature was 25 °C, the signal was the strongest. Therefore, the incubation temperature of PtNP-T10 nanozyme with antimony(III) was selected as 25 °C; the effect of incubation time on the detection effect was investigated, and three temperature conditions of 25 °C, 35 °C, and 45 °C were selected for investigation.

[0081] Figure 7 The detection results of PtNP-T10 nanozyme for antimony(III) under different temperature conditions. The experimental results showed that different incubation temperatures had little effect on the detection results. Considering the simplicity and uniformity of experimental operation, the incubation temperature of PtNP-T10 nanozyme with antimony(III) was selected as 25 °C at room temperature.

[0082] Experiment 5: To investigate the effect of the incubation of antimony(III) with PtNP-T10 nanozyme for different times on its detection.

[0083] 10 min, 30 min, 60 min, 90 min, 120 min, and 180 min were respectively selected for investigation.

[0084] Figure 8 The detection results of PtNP-T10 nanozyme for antimony(III) under different incubation times. The figure shows that when the incubation time was 30 min, the signal had reached the plateau. Therefore, the incubation time of PtNP-T10 nanozyme with antimony(III) was selected as 30 min.

[0085] Experiment 6: Specificity analysis of PtNP-T10 nanozyme for the detection of antimony(III).

[0086] Antimony(III), antimony(V), arsenic(III), bismuth(III) with the same concentration and Cu 2+ Ag + Pb 2+ Hg + Fe 3+ Zn 2+ Mg 2+ Ba 2+ Ca 2+ Na + and K + were respectively added to PtNP-T10 nanozyme. Other operations were the same as the above steps. The absorbance value A at a wavelength of 652 nm was measured, and the (A0 - A) values corresponding to different metal ions were calculated.

[0087] Figure 9 Specific analysis results of PtNP-T10 nanozyme for antimony(III) detection. As shown in the figure, it indicates that only when antimony(III) is present, the catalytic activity of PtNP-T10 nanozyme will be significantly inhibited. Therefore, this method has good specificity.

[0088] Example 3

[0089] A PtNP-T5 nanozyme of the present invention is prepared by the following method:

[0090] (1) Mix 5 μL of H2PtCl6 with a concentration of 10 mM and 10 μL of T5 (the nucleotide sequence of T5 is: TTTTT.) in an aqueous solution thoroughly, and incubate with shaking at room temperature for 20 min.

[0091] (2) Add 8 μL of NaBH4 with a concentration of 20 mM to the reaction system, mix thoroughly with shaking. The solution turns brown, indicating that the PtNP-T5 nanozyme is successfully prepared.

[0092] Example 4

[0093] A PtNP-T15 nanozyme of the present invention is prepared by the following method:

[0094] (1) Mix 5 μL of H2PtCl6 with a concentration of 10 mM and 10 μL of T15 (the nucleotide sequence of T15 is: TTTTTTTTTTTTTTTT.) in an aqueous solution thoroughly, and incubate with shaking at room temperature for 20 min.

[0095] (2) Add 8 μL of NaBH4 with a concentration of 20 mM to the reaction system, mix thoroughly with shaking. The solution turns brown, indicating that the PtNP-T15 nanozyme is successfully prepared.

[0096] Example 5

[0097] A PtNP-T20 nanozyme of the present invention is prepared by the following method:

[0098] (1) Mix 5 μL of H2PtCl6 with a concentration of 10 mM and 10 μL of T20 (the nucleotide sequence of T20 is: TTTTTTTTTTTTTTTTTTTTT.) in an aqueous solution thoroughly, and incubate with shaking at room temperature for 20 min.

[0099] (2) Add 8 μL of NaBH4 with a concentration of 20 mM to the reaction system, mix thoroughly with shaking. The solution turns brown, indicating that the PtNP-T20 nanozyme is successfully prepared.

[0100] Experiment 7: Influence of PtNP-Tn Nanozyme Mediated by T Base Sequences with Different Lengths on the Detection of Antimony(Ⅲ)

[0101] Method: Mix 10 μL of 10 μM T5, T10, T15, and T20 with 5 μL of 10 mM H2PtCl6 thoroughly in an aqueous solution and incubate them with shaking at room temperature for 20 min. After incubation, add 8 μL of 20 mM NaBH4 to the above solution and mix well by shaking. The solution turns brown, indicating that the PtNP-Tn nanozyme has been successfully prepared. Use them for the detection of antimony(Ⅲ) respectively

[0102] Figure 10 This is the influence of PtNP-Tn nanozyme mediated by T base sequences with different lengths on the detection of antimony(Ⅲ). The experimental results show that DNA sequences with lengths of T5, T10, T15, and T20 can all be used for the detection of antimony(Ⅲ).

[0103] As mentioned above, it is only a preferred embodiment of the present invention and does not impose any form of limitation on the present invention. Although the present invention has been disclosed above with preferred embodiments, it is not intended to limit the present invention. Any person skilled in the art can make many possible changes and modifications to the technical solution of the present invention, or modify it into an equivalent embodiment with equivalent changes, without departing from the spirit and technical solution of the present invention. Therefore, any simple modification, equivalent replacement, equivalent change, and modification made to the above embodiments based on the technical essence of the present invention without departing from the content of the technical solution of the present invention still fall within the scope of protection of the technical solution of the present invention.

Claims

1. Application of PtNP-Tn nanozyme in detecting trivalent antimony, characterized in that, The PtNP-Tn nanozyme is synthesized with H2PtCl6 as a precursor under the mediation of polyT template; the polyT is one of T5, T10, T15, and T20; The DNA sequence of T5 is: 5’-TTTTT-3’; The DNA sequence of T10 is: 5’-TTTTTTTTTT-3’; The DNA sequence of T15 is: 5’-TTTTTTTTTTTTTTT-3’; The DNA sequence of T20 is: 5’-TTTTTTTTTTTTTTTTTTTT-3’.

2. The application according to claim 1, wherein The preparation method of the PtNP-Tn nanozyme includes the following steps: S1. Mix H2PtCl6 and polyT, and incubate with shaking; S2. Add NaBH4 into the reaction system, and the solution color turns brown to complete the preparation of the PtNP-Tn nanozyme.

3. The application according to claim 2, wherein The molar concentration ratio of H2PtCl6 to polyT is 500﹕1.

4. The application according to claim 2, wherein The conditions for incubation with shaking are: incubate with shaking for 10 min to 30 min at 25 °C to 45 °C.

5. The application according to any one of claims 1 to 4, characterized in that, The application method includes: (1) Mix the PtNP-Tn nanozyme with the sample to be detected and incubate to obtain mixture one; (2) Mix catalytic substrate solution 1 and catalytic substrate solution 2 evenly according to the molar concentration ratio of 1﹕1 to obtain mixture two; (3) Mix the mixture one and the mixture two, and measure the absorbance A value at a wavelength of 652 nm by an enzyme-labeling instrument. The trivalent antimony concentration of the sample to be detected is positively correlated with the value of A0 - A; A0 is the absorbance value at a wavelength of 652 nm when the trivalent antimony concentration is 0, The components of the catalytic substrate solution 1 include: acetic acid buffer solution containing H2O2; The components of the catalytic substrate solution 2 include: 3,3',5,5'-tetramethylbenzidine.

6. A detection kit for detecting trivalent antimony, characterized in that, It includes the PtNP-Tn nanozyme described in claim 1, catalytic substrate solution 1, and catalytic substrate solution 2; The components of the catalytic substrate solution 1 include: acetic acid buffer solution containing H2O2; The components of the catalytic substrate solution 2 include: 3,3',5,5'-tetramethylbenzidine.

7. The detection kit according to claim 6, characterized in that, In the acetic acid buffer solution containing H2O2, the concentration of H2O2 is 1.0 mM, the concentration of HAc-NaAc is 40 mM, and the concentration of 3,3',5,5'-tetramethylbenzidine in the catalytic substrate solution 2 is 1.0 mM.

8. Application of the detection kit described in claim 6 or 7 in detecting trivalent antimony.

9. The application according to claim 8, characterized in that The application method is: (1) Mix the PtNP-Tn nanozyme with the sample to be detected and incubate to obtain mixture one; (2) Mix catalytic substrate solution 1 and catalytic substrate solution 2 evenly according to the molar concentration ratio of 1﹕1 to obtain mixture two; (3) Mix the mixture one and the mixture two, and measure the absorbance A value at a wavelength of 652 nm by an enzyme-labeling instrument. The trivalent antimony concentration of the sample to be detected is positively correlated with the value of A0 - A; A0 is the absorbance value at a wavelength of 652 nm when the trivalent antimony concentration is 0.

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