Construction and application of a self-opening aptamer sensor based on interface oxidation-induced h2o2 etching

Abstract

This invention discloses the construction and application of a self-opening aptamer sensor based on interface oxidation-induced H2O2 etching, belonging to the fields of photoelectrochemistry, analytical chemistry, and materials science. In this invention, L-tryptophan and ascorbic acid react under a given voltage to generate H2O2, which can etch NaF4:Eu 3+ @Ag's outer Ag shell releases luminescent NaF4:Eu 3+ This method achieves self-on signal activation. When myopoietin antigen is present, the aptamer linked to L-tryptophan detaches from the electrode surface due to its specific binding with the myopoietin aptamer. Consequently, H₂O₂ generation is interrupted, terminating the etching of the Ag shell and causing the signal to shut off. Based on this, the constructed aptamer sensor can sensitively detect myopoietin over a wide concentration range of 1 pg / mL to 10 μg / mL, with a detection limit of 296.15 fg / mL. This strategy based on interface oxidation-induced H₂O₂ etching expands the construction methods of self-on sensors and provides a valuable reference for the early diagnosis of rhabdomyosarcoma.

Description

Technical Field

[0001] This invention discloses the construction and application of a self-opening aptamer sensor based on interface oxidation-induced H2O2 etching, belonging to the fields of photoelectrochemistry, analytical chemistry, and materials science and technology. Background Technology

[0002] Rhabdomyosarcoma (RMS) is a malignant tumor originating from primitive skeletal muscle cells. It is the most common subtype of soft tissue sarcoma in children and can metastasize early via hematogenous and lymphatic spread, exhibiting high malignant potential. Because early RMS primarily presents as a painless mass, diagnostic methods are relatively limited, and imaging examinations are prone to misdiagnosis. Therefore, achieving early and effective diagnosis of RMS is crucial. However, there are few reports in the literature regarding the diagnostic assessment of RMS. Myopoietin (MyoG) is a characteristic biomarker of RMS, and achieving sensitive detection of MyoG is of significant value for the diagnosis of RMS. Electrochemiluminescence (ECL) technology has superior detection sensitivity and ease of operation, and has become an effective method for the early diagnosis of various diseases. Based on this, we developed an ECL-based detection platform for sensitive detection of MyoG, enabling rapid and accurate clinical diagnosis of RMS.

[0003] Signal self-opening strategies are an effective means of constructing sensors, characterized by high sensitivity, strong controllability, low background signal, and fast response speed. In ECL analysis, one method to achieve signal self-opening is to control the signal of the luminescent material through a redox reaction triggered by a functional substance. For example, researchers have used the redox reaction between MnO2 and glutathione to generate Mn 2+ First, the resonant energy transfer between MnO2 and luminol is eliminated, enabling the signal to self-open. Second, researchers designed a label-free "signal self-opening" sensor using luminol as the luminescent agent and reactive oxygen species generated in situ through redox reactions of ascorbic acid and dissolved oxygen as co-reactants. Furthermore, to obtain a more pronounced ECL signal in the presence of a target, a catalyst can be introduced to improve the self-opening signal by accelerating the generation of co-reactant radicals. Studies show that noble metal catalysts exhibit significantly better catalytic activity for K2S2O8 than non-noble metal catalysts. This superior catalytic property is achieved through improved electron transfer efficiency, surface plasmon resonance effect, and chemical stability in oxidizing environments. Based on this, noble metal-based materials can serve as effective catalysts for developing ultrasensitive biosensing systems.

[0004] In this invention, NaF4:Eu with a core-shell structure is used. 3+Using @Ag as the luminescent material and Au@Pt nanoblocks as the catalyst, an ultrasensitive aptamer sensor for MyoG detection was constructed. The signal self-opening mode was achieved through an interfacial oxidation-induced H2O2 etching strategy, which includes three processes: L-tryptophan oxidation, ascorbic acid dehydrogenation, H2O2 generation, and induced etching. Specifically, L-tryptophan binds to the MyoG aptamer and is immobilized on the electrode surface. Subsequently, L-tryptophan is oxidized to generate an intermediate, promoting ascorbic acid dehydrogenation, thereby generating H2O2 to etch NaF4:Eu. 3+ The Ag shell of @Ag triggers the signal. In the presence of MyoG antigen, the specific binding between the MyoG antigen and the MyoG aptamer is stronger than the base pairing between the MyoG aptamer and complementary DNA, causing the L-tryptophan-bound MyoG aptamer to detach from the electrode surface. This dissociation process terminates the etching reaction, resulting in a decrease in sensor signal with increasing MyoG antigen concentration. Based on this strategy, the constructed aptamer sensor achieves ultrasensitive detection of MyoG, with a detection range from 1 pg / mL to 10 μg / mL and a detection limit as low as 296.15 fg / mL. The significant signal change substantially improves the sensor's sensitivity, enabling ultrasensitive detection of MyoG and demonstrating great clinical application potential in the early detection of RMS. Summary of the Invention

[0005] One of the technical tasks of this invention is to overcome the shortcomings of the prior art and to design a highly efficient signal self-opening sensing mode based on the etching of H2O2 induced by interface oxidation.

[0006] The second technical objective of this invention is to construct a self-opening aptamer sensor based on interface oxidation-induced H2O2 etching using a designed signal self-opening sensing mode. The raw materials used are low-cost, the process is simple, and the operation is safe. The third technical objective of this invention is to provide the application of the self-opening aptamer sensor based on interface oxidation-induced H2O2 etching constructed by the above-described method, namely, for the trace detection of MyoG in serum, which has certain industrialization prospects.

[0007] To achieve the above objectives, the technical solution adopted by the present invention is as follows:

[0008] 1. Construction of a self-opening aptamer sensor based on interface oxidation-induced H2O2 etching

[0009] The glassy carbon electrode surface was polished with Al2O3 powder; 5 μL of Au@Pt solution was added dropwise to the polished electrode surface; 6–10 μL of NaF4:Eu solution with a concentration of 10 mg / mL was added. 3+@Ag was added to the modified electrode surface; 5 μL of complementary DNA of MyoG aptamer at a concentration of 50 μM was added; 5 μL of L-tryptophan-modified MyoG aptamer was added, and the mixture was incubated at 4 °C for 2 h to construct a self-opening aptamer sensor based on interface oxidation-induced H2O2 etching.

[0010] The Au@Pt solution is prepared by adding 20 μL of 1% HAuCl4·3H2O and 1 mL of 10 mM hexadecyltrimethylammonium bromide to 50 μL of 10 mM NaBH4 solution; stirring the resulting solution thoroughly for 5 min and allowing it to stand at room temperature for 1.5 h to obtain the Au seed solution; adding 0.9 g of hexadecyltrimethylammonium bromide and 0.1 g of 5-bromosalicylic acid to 25 mL of ultrapure water at 60 °C, followed by the addition of 0.8 g of AgNO3; stirring for 15 min, and then adding 1 mL of 1% HAuCl4. ·3H2O; continue stirring for 15 min, add 0.5 g of ascorbic acid; then, add 1 mL of Au seed solution to the above solution and stir vigorously for 3 min, the solution color turns wine red, and Au nanoblock solution is obtained; dissolve 40 mg of hexadecyltrimethylammonium bromide and 4 mg of 5-bromosalicylic acid in 2 mL of ultrapure water, and add the resulting solution to 2 mL of the prepared Au nanoblock solution; add 6.2 μL of 1% H2PtCl6 to the above mixed solution, then add 8.3 μL of HCl, stir for 2 min, and Au@Pt solution is obtained;

[0011] The NaF4:Eu 3+ @Ag, 2.2g of Eu(NO3)3·6H2O, 1.2g of C6H5Na3O7·2H2O, and 3g of NaNO3 were added to 10mL of ultrapure water and stirred continuously for 20min at room temperature; 0.25g of NaF was dissolved in the above solution and stirred thoroughly; the resulting solution was transferred to a stainless steel high-pressure reactor lined with polytetrafluoroethylene and reacted at 180℃ for 12h; centrifugation and washing with C6H5Na3O7·2H2O solution yielded white NaF4:Eu 3+ Powder; NaF4:Eu 3+ The powder was dispersed in 15 mL of C6H5Na3O7·2H2O solution, and then 4 mL of 50 mM AgNO3 solution was added to the mixture. The mixture was then reacted at 100 °C for 2 h, followed by centrifugation and washing to obtain NaF4:Eu. 3+ @Ag;

[0012] The modified L-tryptophan MyoG aptamer was prepared by dissolving 0.1 g of L-tryptophan in 1 mL of phosphate buffer solution; then adding 100 μL of a mixed solution containing 0.4 M of 1-ethyl-3-(3-dimethylaminopropyl)carbodiimide and 0.1 M of N-hydroxysuccinimide, and shaking at 4 °C for 12 h to activate its carboxyl group; finally, adding 1 mL of 50 μM MyoG aptamer to the resulting mixed solution and shaking at 4 °C for 4 h to obtain the modified L-tryptophan MyoG aptamer.

[0013] 2. The application of the self-opening aptamer sensor constructed by the described method based on interface oxidation-induced H2O2 etching for the trace detection of MyoG in serum.

[0014] Different concentrations of MyoG antigen were modified onto the constructed aptamer sensor and incubated for 1 h. A three-electrode system was formed using the MyoG antigen-modified self-opening aptamer sensor as the working electrode, an Ag / AgCl electrode as the reference electrode, and a platinum electrode as the auxiliary electrode for ECL assay. A phosphate buffer solution containing 50–100 mM K2S2O8 at pH 7.4 was used as the detection solution. The applied scanning voltage range was 1.8–0 V, and the high voltage was 800 V. Based on the measured signals, a working curve was plotted, showing that the detection range of the ECL biosensor was 1 pg / mL–10 μg / mL, with a detection limit as low as 296.15 fg / mL. It also exhibited high stability, selectivity, and reproducibility, making it suitable for trace detection of MyoG in serum.

[0015] The beneficial technical effects of the present invention are as follows:

[0016] 1. This invention designs a highly efficient signal self-opening sensing mode based on interface oxidation-induced H2O2 etching, which expands the construction method of self-opening sensors;

[0017] 2. This invention constructs a self-opening aptamer sensor based on interface oxidation-induced H2O2 etching. Specifically, it utilizes a core-shell structure of NaF4:Eu... 3+ Using @Ag as the luminescent material and Au@Pt nanoblocks as the catalyst, the signal self-opening strategy includes three processes: oxidation of L-tryptophan, dehydrogenation of ascorbic acid, generation of H2O2, and induced etching, which effectively improves the detection sensitivity of the sensing system.

[0018] 3. The self-opening aptamer sensor based on interface oxidation-induced H2O2 etching constructed in this invention exhibits a wide linear range and low detection limit for the target MyoG, as well as high stability, specificity and reproducibility. It is suitable for trace monitoring of MyoG in serum and has certain industrialization prospects. Detailed Implementation

[0019] The present invention will be further described below with reference to the accompanying drawings and specific embodiments. However, the scope of protection of the present invention is not limited thereto. Any changes made to the technical solutions of the present invention by those skilled in the art should fall within the scope of protection of the present invention.

[0020] Example 1: Construction of a self-opening aptamer sensor based on interface oxidation-induced H2O2 etching. The glassy carbon electrode surface was polished with Al2O3 powder; 5 μL of Au@Pt solution was added dropwise to the polished electrode surface; 6 μL of NaF4:Eu solution with a concentration of 10 mg / mL was added... 3+ @Ag was added to the modified electrode surface; 5 μL of complementary DNA of MyoG aptamer at a concentration of 50 μM was added; 5 μL of L-tryptophan-modified MyoG aptamer was added, and the mixture was incubated at 4 °C for 2 h to construct a self-opening aptamer sensor based on interface oxidation-induced H2O2 etching.

[0021] The Au@Pt solution is prepared by adding 20 μL of 1% HAuCl4·3H2O and 1 mL of 10 mM hexadecyltrimethylammonium bromide to 50 μL of 10 mM NaBH4 solution; stirring the resulting solution thoroughly for 5 min and allowing it to stand at room temperature for 1.5 h to obtain the Au seed solution; adding 0.9 g of hexadecyltrimethylammonium bromide and 0.1 g of 5-bromosalicylic acid to 25 mL of ultrapure water at 60 °C, followed by the addition of 0.8 g of AgNO3; stirring for 15 min, and then adding 1 mL of 1% HAuCl4. ·3H2O; continue stirring for 15 min, add 0.5 g of ascorbic acid; then, add 1 mL of Au seed solution to the above solution and stir vigorously for 3 min, the solution color turns wine red, and Au nanoblock solution is obtained; dissolve 40 mg of hexadecyltrimethylammonium bromide and 4 mg of 5-bromosalicylic acid in 2 mL of ultrapure water, and add the resulting solution to 2 mL of the prepared Au nanoblock solution; add 6.2 μL of 1% H2PtCl6 to the above mixed solution, then add 8.3 μL of HCl, stir for 2 min, and Au@Pt solution is obtained;

[0022] The NaF4:Eu 3+ @Ag, 2.2g of Eu(NO3)3·6H2O, 1.2g of C6H5Na3O7·2H2O, and 3g of NaNO3 were added to 10mL of ultrapure water and stirred continuously for 20min at room temperature; 0.25g of NaF was dissolved in the above solution and stirred thoroughly; the resulting solution was transferred to a stainless steel high-pressure reactor lined with polytetrafluoroethylene and reacted at 180℃ for 12h; centrifugation and washing with C6H5Na3O7·2H2O solution yielded white NaF4:Eu 3+ Powder; NaF4:Eu3+ The powder was dispersed in 15 mL of C6H5Na3O7·2H2O solution, and then 4 mL of 50 mM AgNO3 solution was added to the mixture. The mixture was then reacted at 100 °C for 2 h, followed by centrifugation and washing to obtain NaF4:Eu. 3+ @Ag;

[0023] The modified L-tryptophan MyoG aptamer was prepared by dissolving 0.1 g of L-tryptophan in 1 mL of phosphate buffer solution; then adding 100 μL of a mixed solution containing 0.4 M of 1-ethyl-3-(3-dimethylaminopropyl)carbodiimide and 0.1 M of N-hydroxysuccinimide, and shaking at 4 °C for 12 h to activate its carboxyl group; finally, adding 1 mL of 50 μM MyoG aptamer to the resulting mixed solution and shaking at 4 °C for 4 h to obtain the modified L-tryptophan MyoG aptamer.

[0024] Example 2: Construction of a self-opening aptamer sensor based on interface oxidation-induced H2O2 etching. The glassy carbon electrode surface was polished with Al2O3 powder; 5 μL of Au@Pt solution was added dropwise to the polished electrode surface; 8 μL of NaF4:Eu solution with a concentration of 10 mg / mL was added... 3+ @Ag was added to the modified electrode surface; 5 μL of complementary DNA of MyoG aptamer at a concentration of 50 μM was added; 5 μL of L-tryptophan-modified MyoG aptamer was added, and the mixture was incubated at 4 °C for 2 h to construct a self-opening aptamer sensor based on interface oxidation-induced H2O2 etching.

[0025] The Au@Pt solution is prepared by adding 20 μL of 1% HAuCl4·3H2O and 1 mL of 10 mM hexadecyltrimethylammonium bromide to 50 μL of 10 mM NaBH4 solution; stirring the resulting solution thoroughly for 5 min and allowing it to stand at room temperature for 1.5 h to obtain the Au seed solution; adding 0.9 g of hexadecyltrimethylammonium bromide and 0.1 g of 5-bromosalicylic acid to 25 mL of ultrapure water at 60 °C, followed by the addition of 0.8 g of AgNO3; stirring for 15 min, and then adding 1 mL of 1% HAuCl4. ·3H2O; continue stirring for 15 min, add 0.5 g of ascorbic acid; then, add 1 mL of Au seed solution to the above solution and stir vigorously for 3 min, the solution color turns wine red, and Au nanoblock solution is obtained; dissolve 40 mg of hexadecyltrimethylammonium bromide and 4 mg of 5-bromosalicylic acid in 2 mL of ultrapure water, and add the resulting solution to 2 mL of the prepared Au nanoblock solution; add 6.2 μL of 1% H2PtCl6 to the above mixed solution, then add 8.3 μL of HCl, stir for 2 min, and Au@Pt solution is obtained;

[0026] The NaF4:Eu 3+ @Ag, 2.2g of Eu(NO3)3·6H2O, 1.2g of C6H5Na3O7·2H2O, and 3g of NaNO3 were added to 10mL of ultrapure water and stirred continuously for 20min at room temperature; 0.25g of NaF was dissolved in the above solution and stirred thoroughly; the resulting solution was transferred to a stainless steel high-pressure reactor lined with polytetrafluoroethylene and reacted at 180℃ for 12h; centrifugation and washing with C6H5Na3O7·2H2O solution yielded white NaF4:Eu 3+ Powder; NaF4:Eu 3+ The powder was dispersed in 15 mL of C6H5Na3O7·2H2O solution, and then 4 mL of 50 mM AgNO3 solution was added to the mixture. The mixture was then reacted at 100 °C for 2 h, followed by centrifugation and washing to obtain NaF4:Eu. 3+ @Ag;

[0027] The modified L-tryptophan MyoG aptamer was prepared by dissolving 0.1 g of L-tryptophan in 1 mL of phosphate buffer solution; then adding 100 μL of a mixed solution containing 0.4 M of 1-ethyl-3-(3-dimethylaminopropyl)carbodiimide and 0.1 M of N-hydroxysuccinimide, and shaking at 4 °C for 12 h to activate its carboxyl group; finally, adding 1 mL of 50 μM MyoG aptamer to the resulting mixed solution and shaking at 4 °C for 4 h to obtain the modified L-tryptophan MyoG aptamer.

[0028] Example 3: Construction of a self-opening aptamer sensor based on interface oxidation-induced H2O2 etching. The glassy carbon electrode surface was polished with Al2O3 powder; 5 μL of Au@Pt solution was added dropwise to the polished electrode surface; 10 μL of NaF4:Eu solution with a concentration of 10 mg / mL was added... 3+ @Ag was added to the modified electrode surface; 5 μL of complementary DNA of MyoG aptamer at a concentration of 50 μM was added; 5 μL of L-tryptophan-modified MyoG aptamer was added, and the mixture was incubated at 4 °C for 2 h to construct a self-opening aptamer sensor based on interface oxidation-induced H2O2 etching.

[0029] The Au@Pt solution is prepared by adding 20 μL of 1% HAuCl4·3H2O and 1 mL of 10 mM hexadecyltrimethylammonium bromide to 50 μL of 10 mM NaBH4 solution; stirring the resulting solution thoroughly for 5 min and allowing it to stand at room temperature for 1.5 h to obtain the Au seed solution; adding 0.9 g of hexadecyltrimethylammonium bromide and 0.1 g of 5-bromosalicylic acid to 25 mL of ultrapure water at 60 °C, followed by the addition of 0.8 g of AgNO3; stirring for 15 min, and then adding 1 mL of 1% HAuCl4. ·3H2O; continue stirring for 15 min, add 0.5 g of ascorbic acid; then, add 1 mL of Au seed solution to the above solution and stir vigorously for 3 min, the solution color turns wine red, and Au nanoblock solution is obtained; dissolve 40 mg of hexadecyltrimethylammonium bromide and 4 mg of 5-bromosalicylic acid in 2 mL of ultrapure water, and add the resulting solution to 2 mL of the prepared Au nanoblock solution; add 6.2 μL of 1% H2PtCl6 to the above mixed solution, then add 8.3 μL of HCl, stir for 2 min, and Au@Pt solution is obtained;

[0030] The NaF4:Eu 3+ @Ag, 2.2g of Eu(NO3)3·6H2O, 1.2g of C6H5Na3O7·2H2O, and 3g of NaNO3 were added to 10mL of ultrapure water and stirred continuously for 20min at room temperature; 0.25g of NaF was dissolved in the above solution and stirred thoroughly; the resulting solution was transferred to a stainless steel high-pressure reactor lined with polytetrafluoroethylene and reacted at 180℃ for 12h; centrifugation and washing with C6H5Na3O7·2H2O solution yielded white NaF4:Eu 3+ Powder; NaF4:Eu 3+ The powder was dispersed in 15 mL of C6H5Na3O7·2H2O solution, and then 4 mL of 50 mM AgNO3 solution was added to the mixture. The mixture was then reacted at 100 °C for 2 h, followed by centrifugation and washing to obtain NaF4:Eu. 3+ @Ag;

[0031] The modified L-tryptophan MyoG aptamer was prepared by dissolving 0.1 g of L-tryptophan in 1 mL of phosphate buffer solution; then adding 100 μL of a mixed solution containing 0.4 M of 1-ethyl-3-(3-dimethylaminopropyl)carbodiimide and 0.1 M of N-hydroxysuccinimide, and shaking at 4 °C for 12 h to activate its carboxyl group; finally, adding 1 mL of 50 μM MyoG aptamer to the resulting mixed solution and shaking at 4 °C for 4 h to obtain the modified L-tryptophan MyoG aptamer.

[0032] Example 4 describes the application of a self-opening aptamer sensor based on interface oxidation-induced H2O2 etching constructed using the methods described in Examples 1, 2, and 3, for the trace detection of MyoG in serum. 8 μL of MyoG antigen at different concentrations was modified onto the constructed aptamer sensor and incubated for 1 h. A three-electrode system was formed using the MyoG antigen-modified self-opening aptamer sensor as the working electrode, an Ag / AgCl electrode as the reference electrode, and a platinum electrode as the auxiliary electrode for ECL testing. A phosphate buffer solution containing 50 mM K2S2O8 at pH 7.4 was used as the detection solution. The applied scanning voltage range was 1.8–0 V, with a high voltage of 800 V. Based on the measured signals, a working curve was plotted, revealing that the ECL biosensor has a detection range of 1 pg / mL to 10 μg / mL, a detection limit as low as 296.15 fg / mL, and exhibits high stability, selectivity, and reproducibility, making it suitable for the trace detection of MyoG in serum.

[0033] Example 5 describes the application of a self-opening aptamer sensor based on interface oxidation-induced H2O2 etching constructed using the methods described in Examples 1, 2, and 3, for the trace detection of MyoG in serum. 8 μL of MyoG antigen at different concentrations was modified onto the constructed aptamer sensor and incubated for 1 h. A three-electrode system was formed using the MyoG antigen-modified self-opening aptamer sensor as the working electrode, an Ag / AgCl electrode as the reference electrode, and a platinum electrode as the auxiliary electrode for ECL testing. A phosphate buffer solution containing 80 mM K2S2O8 at pH 7.4 was used as the detection solution. The applied scanning voltage range was 1.8–0 V, with a high voltage of 800 V. Based on the measured signals, a working curve was plotted, revealing that the ECL biosensor has a detection range of 1 pg / mL to 10 μg / mL, a detection limit as low as 296.15 fg / mL, and exhibits high stability, selectivity, and reproducibility, making it suitable for the trace detection of MyoG in serum.

[0034] Example 6 describes the application of a self-opening aptamer sensor based on interface oxidation-induced H2O2 etching constructed using the methods described in Examples 1, 2, and 3, for the trace detection of MyoG in serum. 8 μL of MyoG antigen at different concentrations was modified onto the constructed aptamer sensor and incubated for 1 h. A three-electrode system was formed using the MyoG antigen-modified self-opening aptamer sensor as the working electrode, an Ag / AgCl electrode as the reference electrode, and a platinum electrode as the auxiliary electrode for ECL testing. A phosphate buffer solution containing 100 mM K2S2O8 at pH 7.4 was used as the detection solution. The applied scanning voltage range was 1.8–0 V, with a high voltage of 800 V. Based on the measured signals, a working curve was plotted, revealing that the ECL biosensor has a detection range of 1 pg / mL to 10 μg / mL, a detection limit as low as 296.15 fg / mL, and exhibits high stability, selectivity, and reproducibility, making it suitable for the trace detection of MyoG in serum. Attached Figure Description

[0035] Figure 1 The flowchart shows the construction process of a self-opening aptamer sensor based on interface oxidation-induced H2O2 etching (Au@Pt nanoblocks: Au@PtNBs; L-tryptophan: L-Trp; L-tryptophan-modified MyoG aptamer: L-Apta-Trp; ascorbic acid: AA; dehydroascorbic acid: DHA).

[0036] Figure 2 NaF4:Eu 3+ X-ray diffraction pattern of @Ag.

[0037] Figure 3 (A)NaF4:Eu 3+ The transmission electron microscope image of @Ag and the elemental mapping diagram corresponding to (B).

[0038] Figure 4 NaF4:Eu 3+ X-ray photoelectron spectra of Ag, including (A) the whole region X-ray photoelectron spectrum; (B) the high-resolution X-ray photoelectron spectrum of the Eu 3d region; and (C) the high-resolution X-ray photoelectron spectrum of the Ag 3d region.

[0039] Figure 5 The X-ray diffraction pattern of Au@PtNBs.

[0040] Figure 6 This is a scanning electron microscope image of Au@PtNBs.

[0041] Figure 7The X-ray photoelectron spectra of Au@Pt NBs are shown below, where (A) is the X-ray photoelectron spectrum of the whole region; (B) is the high-resolution X-ray photoelectron spectrum of the Au4f region; and (C) is the high-resolution X-ray photoelectron spectrum of the Pt4f region.

[0042] Figure 8 For (a)NaF4:Eu 3+ @Ag / Au@PtNBs / GCE and (b)NaF4:Eu 3+ / Au@PtNBs / GCE at S2O8 2- ECL intensity-voltage curve in solution.

[0043] Figure 9 For (a)Apta-L-Trp / DNA / NaF4:Eu 3+ @Ag / Au@PtNBs / GCE at S2O8 2- ECL intensity-voltage curve in solution, and (b) NaF4:Eu 3+ @Ag / Au@Pt NBs / GCE and (c)Apta-L-Trp / DNA / NaF4:Eu 3+ @Ag / Au@Pt NBs / GCE in S2O8 containing AA 2- ECL intensity-voltage curve in solution.

[0044] Figure 10 The image shows the test results of the constructed aptamer sensor using a rotating ring disk electrode in a phosphate buffer solution containing AA.

[0045] Figure 11 The graph shows the yield of H2O2 and the number of electrons transferred.

[0046] Figure 12 The differential pulse voltammetry curves for Au@PtNBs / GCE and GCE are shown.

[0047] Figure 13 For (a)Apta-L-Trp / DNA / NaF4:Eu 3+ @Ag / Au@Pt NBs / GCE and (b)Apta-L-Trp / DNA / NaF4:Eu 3+ ECL intensity-voltage curves of @Ag / GCE in phosphate buffered solution containing AA, and (c)Apta-L-Trp / DNA / NaF4:Eu 3+ @Ag / Au@Pt NBs / GCE and (d)Apta-L-Trp / DNA / NaF4:Eu 3+ @Ag / GCE in S2O8 containing AA 2-ECL intensity-voltage curve in solution.

[0048] Figure 14 The diagram shows the ECL mechanism of the constructed sensing system.

[0049] Figure 15 Characterization diagram of the construction process of a self-opening aptamer sensor based on interface oxidation-induced H2O2 etching, according to (A) cyclic voltammetry and (B) AC impedance testing.

[0050] Figure 16 The diagram shows the condition optimization of a self-opening aptamer sensor based on interface oxidation-induced H2O2 etching. (A) shows the optimized solution pH; (B) shows the NaF4:Eu... 3+ @Ag concentration optimization results; (C)K2S2O8 concentration optimization results.

[0051] Figure 17 The following are the ECL response curves (A) (1 pg / mL, 10 pg / mL, 50 pg / mL, 100 pg / mL, 1 ng / mL, 10 ng / mL, 100 ng / mL, 1 μg / mL and 10 μg / mL) and the corresponding calibration curves (B) of the self-opening aptamer sensor based on interface oxidation-induced H2O2 etching after incubation with different concentrations of MyoG.

[0052] Figure 18 To evaluate the (A) signal stability, (B) storage stability, (C) reproducibility, and (D) selectivity of a self-opening aptamer sensor based on interface oxidation-induced H2O2 etching.

Claims

1. A method for constructing a self-opening aptamer sensor based on interface oxidation-induced H2O2 etching, characterized in that, The glassy carbon electrode surface was polished with Al2O3 powder; 5 μL of Au@Pt solution was added dropwise to the polished electrode surface; 6 ~ 10 μL of NaF4:Eu solution with a concentration of 10 mg / mL was added. 3+ @Ag was added to the modified electrode surface; 5 μL of complementary DNA of the myoblast-poietin aptamer at a concentration of 50 μM was added; 5 μL of L-tryptophan-modified myoblast-poietin aptamer was added, and the mixture was incubated at 4 °C for 2 h to construct a self-opening aptamer sensor based on interface oxidation-induced H2O2 etching; the NaF4:Eu 3+ @Ag represents NaF4:Eu with a core-shell structure. 3+ @Ag, where Ag is the Ag shell.

2. The method for constructing a self-opening aptamer sensor based on interface oxidation-induced H2O2 etching as described in claim 1, characterized in that, The Au@Pt solution was prepared by adding 20 μL of 1% HAuCl4·3H2O and 1 mL of 10 mM hexadecyltrimethylammonium bromide to 50 μL of 10 mM NaBH4 solution; stirring the resulting solution thoroughly for 5 min and allowing it to stand at room temperature for 1.5 h to obtain an Au seed solution; adding 0.9 g of hexadecyltrimethylammonium bromide and 0.1 g of 5-bromosalicylic acid to 25 mL of ultrapure water at 60 ℃, followed by the addition of 0.8 g of AgNO3; stirring for 15 min, then adding 1 mL of 1% HAuCl4·3H2O; continuing to stir for 15 min, then adding 0.5 g of ascorbic acid; subsequently, adding 1 mL of the Au seed solution to the above solution and stirring vigorously for 3 min, until the solution turned wine-red, yielding an Au nanoparticle solution; 40 mg of hexadecyltrimethylammonium bromide and 4 mg of 5-bromosalicylic acid were dissolved in 2 mL of ultrapure water, and the resulting solution was added to 2 mL of the prepared Au nanoblock solution to obtain a mixed solution. 6.2 μL of 1% H2PtCl6 was added to the above mixed solution, followed by 8.3 μL of HCl. After stirring for 2 min, an Au@Pt solution was obtained.

3. The method for constructing a self-opening aptamer sensor based on interface oxidation-induced H2O2 etching as described in claim 1, characterized in that, The NaF4:Eu 3+ @Ag, 2.2 g of Eu(NO3)3·6H2O, 1.2 g of C6H5Na3O7·2H2O, and 3 g of NaNO3 were added to 10 mL of ultrapure water and stirred continuously for 20 min at room temperature; 0.25 g of NaF was dissolved in the above solution and stirred thoroughly; the resulting solution was transferred to a stainless steel high-pressure reactor lined with polytetrafluoroethylene and reacted at 180 ℃ for 12 h; centrifugation and washing with C6H5Na3O7·2H2O solution yielded white NaF4:Eu 3+ Powder; NaF4:Eu 3+ The powder was dispersed in 15 mL of C6H5Na3O7·2H2O solution, and then 4 mL of 50 mM AgNO3 solution was added to the mixture. The mixture was then reacted at 100 °C for 2 h, followed by centrifugation and washing to obtain NaF4:Eu. 3+ @Ag.

4. The method for constructing a self-opening aptamer sensor based on interface oxidation-induced H2O2 etching as described in claim 1, characterized in that, The modified L-tryptophan myocyte aptamer is prepared by dissolving 0.1 g of L-tryptophan in 1 mL of phosphate buffer solution; then adding 100 μL of a mixed solution containing 0.4 M of 1-ethyl-3-(3-dimethylaminopropyl)carbodiimide and 0.1 M of N-hydroxysuccinimide, and shaking at 4 °C for 12 h to activate its carboxyl group. Add 1 mL of 50 μM myocyte cytopoietin aptamer to the resulting mixed solution and shake at 4 °C for 4 h to obtain L-tryptophan-modified myocyte cytopoietin aptamer.

5. An application of a self-opening aptamer sensor based on interface oxidation-induced H2O2 etching constructed by the method described in claim 1, characterized in that, Used for myopoietin detection.

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