A microelectrochemical sensor for detecting amyloid polypeptide Aβ 1-42 and a method for preparing and using the same
By preparing surface molecularly imprinted polymers and heme-binding signal probes on acupuncture needle electrodes, the problem of insufficient sensitivity and selectivity of electrochemical sensors in detecting amyloid peptide Aβ1-42 was solved, achieving efficient and low-cost detection results.
Patent Information
- Application Number
- CN202510099792.0
- Authority / Receiving Office
- CN · China
- Patent Type
- Patents(China)
- Current Assignee / Owner
- Filing Date
- 2025-01-22
- Publication Date
- 2025-11-25
- Estimated Expiration
- 2045-01-22
AI Technical Summary
Existing electrochemical sensors lack sufficient sensitivity and selectivity when detecting amyloid peptide Aβ1-42, and are also costly, making it difficult to meet the requirements for efficient detection.
Surface molecularly imprinted polymers (SMIPs) were prepared on acupuncture needle electrodes using in-situ electropolymerization and self-assembly techniques. Heme was combined as an embedded signal probe, and gold nanoparticles and single-walled carbon nanotubes were modified to enhance electron transfer efficiency and selective recognition capabilities.
The sensitivity and selectivity of the electrochemical sensor were improved, the cost was reduced, and efficient detection of amyloid peptide Aβ1-42 was achieved. It also has good anti-interference ability and stability.
Smart Images
Figure CN119915875B_ABST
Abstract
Description
Technical Field
[0001] This invention belongs to the field of electrochemical technology, specifically relating to a method for detecting amyloid peptide Aβ. 1-42 Microscopic electrochemical sensors, their fabrication methods, and applications. Background Technology
[0002] β-amyloid peptides can influence presynaptic release in hippocampal neurons and have been found to be a major component of senile plaques. Aβ consists of amino acid residues produced by the proteolytic cleavage of amyloid precursor proteins by β- and γ-secretases. Excessive Aβ oligomers can self-aggregate due to hydrophobic interactions and the Leu17-Ala21 self-recognition site. Regular β-sheet structures are key pathogenic factors, potentially leading to neuronal death, synaptic abnormalities, oxidative damage, inflammation, and accelerating disease progression. Aβ 1-42 It is the most important biomarker in the dynamic changes of Alzheimer's disease course.
[0003] Currently, many technologies are available for detecting Aβ. 1-42 This includes enzyme-linked immunosorbent assays (ELISA), capillary isoelectric focusing, scanning tunneling microscopy, magnetic resonance imaging (MRI), surface plasmon resonance (SPR), positron emission tomography (PET), fluorescence microscopy, and electrochemical analysis. Among these, electrochemical sensors have attracted significant attention due to their high sensitivity, insensitivity to sample turbidity, and inherent electronic properties. Electrodes are a fundamental component of electrochemical performance. Acupuncture needles, a traditional medical device, are a relatively new type of medical device developed in recent years. Microelectrodes come in various shapes, are smaller than ordinary planar electrodes, and longer than other microelectrodes. Importantly, acupuncture needle microelectrodes can serve as suitable detectors for implantable non-destructive sensors and have the potential to be integrated with mature acupuncture techniques.
[0004] Molecularly imprinted polymers (MIPs), often referred to as "artificial antibodies," are promising recognition elements because they provide highly specific complementary binding sites and shapes for specific templates within cross-linked polymer networks. MIPs possess unique advantages such as ease of synthesis, simplicity, rapid recognition, high stability, low cost, and good selectivity. In recent years, surface imprinting technology for preparing MIP thin layers on substrates has been developed. Since most template molecules are located on or near the material surface, surface-imprinted polymers are expected to endow electrochemical sensors with significant advantages, including low signal background, rapid binding kinetics, and good anti-interference capabilities. Meanwhile, in-situ electropolymerization is an effective method for preparing surface-imprinted polymer microelectrodes and easily provides suitable nanocavities for smooth electron transfer. The application of surface-imprinting technology to the amyloid peptide Aβ... 1-42 The detection of this substance has significant scientific and commercial value. Summary of the Invention
[0005] To address the above problems, the present invention aims to provide a method for detecting amyloid peptide Aβ. 1-42 Microscopic electrochemical sensors, their fabrication methods, and applications were investigated. A microscopic electrochemical sensor for amyloid peptide Aβ was fabricated on acupuncture needle electrodes using in-situ electropolymerization and self-assembly techniques. 1-42 The SMIP layer contains heme embedded beneath the SMIP layer, allowing current to flow smoothly through the imprinted nanoholes. Furthermore, recombinant amyloid peptide Aβ... 1-42 This blocked the signal. The developed microsensor showed sensitive and selective detection of amyloid peptide Aβ. 1-42 The ability of biomarkers.
[0006] The specific technical solution is as follows:
[0007] A detection method for amyloid peptide Aβ 1-42 The method for fabricating a micro electrochemical sensor includes the following steps:
[0008] 1) Pre-treatment of acupuncture needles: Grind and polish acupuncture needles, ultrasonically clean them, and dry them for later use.
[0009] 2) Modification of gold nanoparticles: The acupuncture needles pretreated in step 1) were used as working electrodes. The needle tips were immersed in a HAuCl4 solution containing KCl and cyclic voltammetry was performed. The resulting electrodes were denoted as ANME / AuNPs.
[0010] 3) Modification with single-walled carbon nanotubes: The ANME / AuNPs electrode obtained in step 2) was used as the working electrode for electropolymerization in an aqueous solution containing 3,4-ethylenedioxythiophene and single-walled carbon nanotubes. After polymerization, the modified electrode was thoroughly washed with water and dried. The prepared electrode was labeled as follows:
[0011] ANME / AuNPs / SWNT;
[0012] 4) Heme modification: The ANME / AuNPs / SWNT electrode prepared in step 3) was immersed in a heme solution and incubated at 4℃~25℃. The resulting electrode was labeled as follows.
[0013] ANME / AuNPs / SWNT~hemin;
[0014] 5) Binding of template molecules: The electrode prepared in step 4) is immersed in Aβ. 1-42 In solution, at 25℃
[0015] Incubate at ~37℃;
[0016] 6) Modification of the imprinted polymer film: Using the electrode treated in step 5) as the working electrode, dopamine and ionic liquid were electropolymerized by cyclic voltammetry scanning;
[0017] 7) Elution of template molecules: The encapsulated amyloid peptide Aβ after step 6) is eluted. 1-42 The template was eluted to obtain a surface molecularly imprinted microsensor.
[0018] ANME / AuNPs / SWNT~hemin~Aβ@SMIP.
[0019] Further, the specific operation process of step 1) is as follows: polish the acupuncture needles, ultrasonically clean them in ethanol and deionized water respectively, and then dry the acupuncture needles with nitrogen for later use.
[0020] Furthermore, in step 2), the scanning rate of the cyclic voltammetry scan is 25–100 mV / s, the potential range alternates between -1.5 V and 0.5 V, the scan is performed for 5–10 cycles, the concentration of the HAuCl4 solution is 2.5 mmol / L, and the 5–10 mm needle tip is immersed in the HAuCl4 solution containing KCl.
[0021] Further, in step 3), the polymerization potential is set to 1–1.2 V, the polymerization time is 100–200 seconds, the concentration of the 3,4-ethylenedioxythiophene solution is 0.01–0.02 mol / L, and the concentration of the single-walled carbon nanotube solution is 0.3–0.5 mol / L.
[0022] Furthermore, in step 4), the solvent for the heme solution is sodium hydroxide with a concentration of 3–5 mM, and the incubation time is 6–12 hours.
[0023] Further, Aβ in step 5) 1-42 The solution is Aβ 1-42 The solution obtained by dissolving in 0.1M PBS, Aβ 1-42 The solution concentration is 10–40 μM, and the incubation time is 30–60 min.
[0024] Further, in step 6), the electropolymerization potential range is -0.5 to 0.5 V, the scan rate is 50 to 100 mV / s, the cyclic scan is 10 to 20 times, the electrolyte is 0.01 M PBS, pH = 7.4, containing 5 to 8 mM dopamine and 20 to 25 mM ionic liquid.
[0025] Furthermore, the elution process in step 7) involves eluting the encapsulated amyloid peptide Aβ. 1-42 The template was eluted with PBS solution containing methanol for 60–120 minutes, with a methanol to PBS volume ratio of 1:20.
[0026] A detection peptide Aβ prepared by the above preparation method 1-42 Miniature electrochemical sensors.
[0027] A detection method for amyloid peptide Aβ 1-42 Applications of miniature electrochemical sensors.
[0028] The beneficial effects of this invention are as follows:
[0029] 1) The cyclic voltammetry scanning used in this invention during the deposition process is more conducive to the deposition of gold on the surface of the acupuncture needle electrode, resulting in a more uniform and dense distribution and a spherical structure. This provides a larger contact area for subsequent modification of the acupuncture needle electrode. This metal structure increases the contact area between the metal layer and the amyloid peptide Aβ after the imprinted electrode forms a cavity during elution. 1-42 The increased contact surface area enhances the efficiency of electron transfer of heme on the electrode, effectively improving the electrocatalytic performance of the electrode.
[0030] 2) In this invention, single-walled carbon nanotubes (SWNTs) are electropolymerized before heme is incorporated. SWNTs possess excellent conductivity, which significantly improves the electron transfer efficiency of heme. The binding of heme molecules to the polymerized SWNTs promotes rapid electron transfer, thereby enhancing electrocatalytic performance. The large surface area of SWNTs provides more binding sites, facilitating the adsorption and stabilization of heme molecules on the surface. The binding of heme to SWNTs not only improves their stability but also extends the lifespan of the prepared sensor.
[0031] 3) This invention selects heme as the built-in signal probe, whose advantages are mainly reflected in high sensitivity, stability, anti-interference ability, simple preparation, and low cost. This makes it an ideal choice for molecularly imprinted electrochemical sensors, especially suitable for detecting non-electroactive target molecules (such as amyloid peptide Aβ). 1-42 This significantly improves the performance of the sensor.
[0032] 4) This invention uses stainless steel acupuncture needles as the sensor substrate, which is small in size, low in cost, and simple in preparation process. Attached Figure Description
[0033] Figure 1 Scanning electron microscope images of bare acupuncture needle electrodes and ANME / AuNPs;
[0034] Figure 2 Cyclic voltammetry diagrams during the step-by-step modification process;
[0035] Figure 3 Cyclic voltammograms of the progressively modified electrode in PBS solution at pH 7;
[0036] Figure 4Differential pulse voltammograms of the stepwise modified electrode in PBS solution at pH 7;
[0037] Figure 5 The fabricated micro-electrochemical sensor targets amyloid peptide Aβ at different concentrations. 1-42 Differential pulse voltammogram of solution for detection;
[0038] Figure 6 The fabricated micro-electrochemical sensor is used for the detection of amyloid peptide Aβ. 1-42 During detection, ΔI(I1-I2) and amyloid peptide Aβ 1-42 Linear relationship graph of concentration logarithm (1gC);
[0039] Figure 7 The micro-electrochemical sensor prepared by binding amyloid peptide Aβ 1-42 And the response results after non-specific molecules;
[0040] Figure 8 The non-molecularly imprinted electrochemical biosensor prepared in Comparative Example 1 was examined before elution, after elution, and after rebinding of the amyloid peptide Aβ. 1-42 The differential pulse voltammogram afterward.
[0041] Figure 9 CV diagrams of electrodes with and without single-walled carbon nanotube modification;
[0042] Figure 10 The DPV diagrams are for electrodes with and without single-walled carbon nanotube modification. Detailed Implementation
[0043] The present invention will be further described below with reference to the accompanying drawings and embodiments, but the scope of protection of the present invention is not limited thereto.
[0044] Example 1
[0045] A detection method for amyloid peptide Aβ 1-42 The method for fabricating a micro electrochemical sensor includes the following steps:
[0046] 1) Pretreatment of acupuncture needles: The acupuncture needles are ground and polished, then ultrasonically cleaned in ethanol and deionized water for 5 minutes each, and finally dried with nitrogen for later use. The bare acupuncture needle electrodes are then scanned using an electron microscope. Figure 1 As shown in A, only longitudinal scratches appear after polishing;
[0047] 2) Modification with gold nanoparticles: Using a pretreated acupuncture needle electrode as the working electrode, a saturated calomel electrode as the reference electrode, and a platinum wire electrode as the counter electrode, a 5mm tip of the acupuncture needle electrode was immersed in a solution containing 2.5mM HAuCl4 and 0.1M KCl. Five cycles of scanning were performed at a scan rate of 25mV·s⁻¹, with the potential alternating between -1.5V and 0.5V. The resulting electrode was labeled ANME / AuNPs. Electron microscopy was then performed on the electrode. Figure 1 As shown in B, after modification with gold nanoparticles, AuNPs aggregate together to form a rough surface; it can be observed that the AuNPs have a uniform particle size distribution, with a particle size range of 80 to 160 nm.
[0048] 3) Modification of single-walled carbon nanotubes: Electropolymerization was carried out in 5.00 mL of an aqueous solution containing 3,4-ethylenedioxythiophene (0.02 M concentration in aqueous solution) and 20 mg of single-walled carbon nanotubes (SWNTs). The polymerization potential was set to 1.2 V, and the polymerization time was 100 seconds. After polymerization, the modified electrode was thoroughly washed with water and dried. The prepared electrode was labeled ANME / AuNPs / SWNT.
[0049] 4) Modification of heme: ANME / AuNPs / SWNT was immersed in 3mM heme (dissolved in 200mM NaOH) and incubated at 4°C for 12 hours to obtain ANME / AuNPs / SWNT~hemin (abbreviated as ANME / / hemin).
[0050] 5) Binding of template molecules: The prepared electrode was immersed in 40 μM Aβ 1-42 Incubate in a solution (dissolved in 0.1M pH=7.5 PBS) at 37°C for 30 minutes, and label as ANME / AuNPs / SWNT~hemin~Aβ. 1-42 ;
[0051] 6) Modification of the imprinted polymerized membrane: Electropolymerization of dopamine and ionic liquid was performed by cyclic voltammetry scanning, with a potential range of -0.5 to 0.5 V, a scan rate of 100 mV / s, and 10 cycles (electrolyte: 0.01 M PBS, pH = 7.4, containing 5 mM dopamine and 20 mM ionic liquid). This was denoted as...
[0052] ANME / AuNPs / SWNT~hemin~Aβ 1-42 / pDA+Ⅱ
[0053] 7) Elution of template molecules: The encapsulated amyloid peptide Aβ is eluted. 1-42The template was eluted with 0.1M (pH=5.0) PBS containing 5% methanol for 120 minutes to obtain the surface molecularly imprinted microsensor.
[0054] ANME / AuNPs / SWNT~hemin~Aβ@SMIP(ANME / / hemin / / SMIP)
[0055] Figure 2 To progressively modify the electrode in the presence of 5.0 mM [Fe(CN)6] 3- / 4- The cyclic voltammograms in 0.1M potassium chloride solution show that the acupuncture needle microelectrode (ANME), with a weaker current intensity, exhibits an oxidation peak (0.4 V) and almost no reduction peak, indicating an irreversible electron transfer process within the ANME, resulting in low conductivity and weak electrochemical activity. However, a pair of significant redox peaks appear after electrodeposition. This is attributed to the excellent electrocatalytic activity of the atomic sites on the gold nanoparticles (AuNPs), and the interaction between ANME, AuNPs, and [Fe(CN)6]. 3- / 4- The heterogeneous electron transfer between them is enhanced. After modification with single-walled carbon nanotubes, the peak current increases, attributed to the large specific surface area and rapid mass transfer channels provided by carbon. The combination of both can significantly improve the electron transfer efficiency and current response of the electrode surface. Self-assembled heme pairs with [Fe(CN)6] 3- / 4- The external probe exhibits good electrochemical activity, increases peak current, and promotes electron transfer in the matrix heterostructure. Therefore, heme is a potentially suitable probe for providing electrochemical signals. (The text then abruptly shifts to a seemingly unrelated topic: "In incubation of amyloid peptide Aβ...") 1-42 Subsequently, the peak current decreased, attributed to the interaction between the central iron atom of heme and Aβ. 1-42 Histidine residues in the protein coordinate with their imidazole groups, thereby binding the non-electrolyte amyloid peptide Aβ. 1-42 Template molecules are immobilized on the electrode surface, further hindering electron transfer. Subsequently, the peak current after electropolymerization of dopamine and ionic liquid decreased significantly, indicating low electrochemical activity. Almost no anodic and cathodic peaks were observed, suggesting that the electropolymerization of dopamine and ionic liquid produced a continuous and dense coating, almost completely blocking [Fe(CN)6]. 3- / 4- The electron transfer should be optimized, and the imprinted layer should act as an anti-interference layer, while also sealing and protecting the electrochemical signal of the built-in heme. Finally, the template amyloid peptide Aβ is placed in an acidic environment. 1-42 An amplified peak current appeared after elution, [Fe(CN)6] 3- / 4- The signal further increased, attributed to the formation of molecularly imprinted cavities that could be used for electron transfer.
[0056] like Figure 3 , Figure 4As shown, the cyclic voltammogram and differential pulse voltammogram of the progressively modified electrode in PBS solution at pH 7 are presented. Due to the electron transfer of the built-in heme, a pair of distinct redox peaks can be observed in the CV curve of ANME / / hemin. It is known that during the electropolymerization process of dopamine and ionic liquids, the small size of the molecules and the self-repulsion effect allow them to tightly cover the needle surface, encapsulating the amyloid peptide Aβ. 1-42 The template is blocked, hindering the electrical signal transmission of the embedded heme. Therefore, the peak current of the embedded heme is significantly reduced during the elution of amyloid peptide Aβ. 1-42 After template application, the peak current of the built-in heme increased again. This is likely due to the presence of the imprinted nanocavities forming an effective current transport channel. However, when the sensor was incubated with the amyloid peptide Aβ... 1-42 After solution preparation, the peak current of the built-in heme decreased again because the amyloid peptide Aβ was successfully captured in the structurally complementary nanocavities. 1-42 Template molecules, thereby blocking the current transport channel. This further demonstrates the effectiveness of using a built-in signal probe for detecting amyloid peptide Aβ. 1-42 The successful fabrication of a miniature electrochemical sensor.
[0057] Application Example 1
[0058] The prepared micro-electrochemical sensor was used in the presence of different concentrations of amyloid peptide Aβ. 1-42 Incubate for 30 minutes in a solution of (30 fM to 50000 nM). Figure 5 As shown, with the amyloid peptide Aβ 1-42 With increasing concentration, the peak current of the built-in heme gradually decreases. This decrease in current is due to the complementary structure of the imprinted nanocavities to the amyloid peptide Aβ. 1-42 Molecular occupancy hinders electron transfer in the built-in heme.
[0059] The prepared micro-electrochemical sensor targets amyloid peptide Aβ. 1-42 During detection, ΔI(I1-I2) (I1: peak current of ANME / / hemin / / SMIP; I2: peak current of ANME / / hemin / / SMIP combined with Aβ again) 1-42 The peak current at the later time. (Value and Aβ) 1-42 There is a strong linear relationship between the logarithms of concentrations, such as Figure 6 As shown, the linear equation is ΔI(μA)=2.018lgC+31.13(R) 2 =0.998). The linear range was 30 fM to 50000 nM, and the detection limit was 0.05 fM. These results demonstrate that the micro-electrochemical sensor can be successfully applied to the amyloid peptide Aβ. 1-42 Sensitive detection; by detecting 40 μMAβ 1-42and Aβ 1-40 Osteopontin (OPN), nucleocapsid protein (SARS-CoV-2N protein, NP), mesothelin (MSLN), vascular endothelial growth factor (VEGF), bovine serum albumin (BSA), Na + Mg 2+ Cl - The specificity of microelectrochemical sensors was studied using uric acid (UA) and dopamine (DA), such as... Figure 7 As shown, the signal changes of the microsensor before and after incubation are both smaller than those at Aβ. 1-42 The signal changes under certain conditions indicate that the sensor has good specificity.
[0060] Comparative Example 1
[0061] To further demonstrate the successful fabrication of the micro-electrochemical sensor, a non-micro-electrochemical sensor was also fabricated, which was not used in step 5) in Aβ. 1-42 Incubation was performed in the solution, and other operations were the same as in Example 1, such as... Figure 8 As shown, before and after elution, and during rebinding of Aβ 1-42 back,
[0062] The peak current of heme changes very little before and after template removal because the ANME / / hemin / / SNIP lacks imprinted nanocavities, thus failing to provide specific recognition and binding sites, leading to the loss of amyloid peptide Aβ peak current. 1-42 It cannot be bound to the electrode surface. The successful fabrication of the micro-electrochemical sensor is further demonstrated by comparing it with a non-micro-electrochemical sensor.
[0063] Comparative Example 2
[0064] To further demonstrate the successful fabrication of the micro electrochemical sensor, ANME / AuNPs / SWNT~hemin and ANME / AuNPs~hemin were also prepared. The operation steps were the same as those in Example 1 (1) to (4), except that ANME / AuNPs~hemin did not have the operation in step (3).
[0065] from Figure 9 (CV diagram) and Figure 10(DPV diagram) shows that the electrode modified with single-walled carbon nanotubes (SWNTs) is more responsive to the electrical signals of heme. The binding between SWNTs and heme typically occurs through interactions and coordination to form complexes. Heme molecules contain iron ions, which can interact with the surface of carbon nanotubes or certain functional groups, thus forming stable complexes. SWNTs possess a high surface area and good conductivity, effectively enhancing the electrocatalytic activity of heme. Surface modification allows SWNTs to provide coordination sites with heme and promote electron transfer, thereby improving their performance in electrochemical sensors. Direct binding of gold to heme is less likely and does not provide a larger binding area.
Claims
1. A detection method for amyloid peptide Aβ 1-42 The method for fabricating a miniature electrochemical sensor is characterized by, Includes the following steps: 1) Pre-treatment of acupuncture needles: Grind and polish acupuncture needles, ultrasonically clean them, and dry them for later use. 2) Modification of gold nanoparticles: The acupuncture needles pretreated in step 1) were used as working electrodes. The needle tips were immersed in a HAuCl4 solution containing KCl and cyclic voltammetry was performed. The resulting electrodes were denoted as ANME / AuNPs. 3) Modification of single-walled carbon nanotubes: The ANME / AuNPs electrode obtained in step 2) was used as the working electrode and electropolymerized in an aqueous solution containing 3,4-ethylenedioxythiophene and single-walled carbon nanotubes. After polymerization, the modified electrode was thoroughly washed with water and dried. The prepared electrode was labeled as ANME / AuNPs / SWNT. 4) Heme modification: The ANME / AuNPs / SWNT electrode prepared in step 3) is immersed in a heme solution and incubated at 4℃~25℃. The resulting electrode is labeled as ANME / AuNPs / SWNT~hemin. 5) Binding of template molecules: The electrode prepared in step 4) is immersed in Aβ. 1-42 Incubate in solution at 25℃~37℃; 6) Modification of the imprinted polymer film: Using the electrode treated in step 5) as the working electrode, dopamine and ionic liquid were electropolymerized by cyclic voltammetry scanning; 7) Elution of template molecules: The encapsulated amyloid peptide Aβ after step 6) is eluted. 1-42 The template was eluted to obtain a surface molecularly imprinted microsensor. ANME / AuNPs / SWNT~hemin~Aβ@SMIP.
2. The method for detecting amyloid peptide Aβ as described in claim 1 1-42 The method for fabricating a miniature electrochemical sensor is characterized by, The specific operation process of step 1) is as follows: polish the acupuncture needles, ultrasonically clean them in ethanol and deionized water respectively, and then dry the acupuncture needles with nitrogen for later use.
3. The method for detecting amyloid peptide Aβ as described in claim 1 1-42 The method for fabricating a miniature electrochemical sensor is characterized by, In step 2), the scanning rate of the cyclic voltammetry scan is 25–100 mV / s, the potential range alternates between -1.5 V and 0.5 V, the scan is performed for 5–10 cycles, the concentration of the HAuCl4 solution is 2.5 mmol / L, and the 5–10 mm needle tip is immersed in the HAuCl4 solution containing KCl.
4. The method for detecting amyloid peptide Aβ as described in claim 1 1-42 The method for fabricating a miniature electrochemical sensor is characterized by, In step 3), the polymerization potential is set to 1–1.2 V, the polymerization time is 100–200 seconds, the concentration of the 3,4-ethylenedioxythiophene solution is 0.01–0.02 mol / L, and the concentration of the single-walled carbon nanotube solution is 0.3–0.5 mol / L.
5. The method for detecting amyloid peptide Aβ as described in claim 1 1-42 The method for fabricating a miniature electrochemical sensor is characterized by, The solvent for the heme solution in step 4) is sodium hydroxide with a concentration of 3-5 mM, and the incubation time is 6-12 hours.
6. The method for detecting amyloid peptide Aβ as described in claim 1 1-42 The method for fabricating a miniature electrochemical sensor is characterized by, Step 5) Aβ 1-42 The solution is Aβ 1-42 The solution obtained by dissolving in 0.1M PBS, Aβ 1-42 The solution concentration is 10–40 μM, and the incubation time is 30–60 min.
7. The method for detecting amyloid peptide Aβ as described in claim 1 1-42 The method for fabricating a miniature electrochemical sensor is characterized by, In step 6), the electropolymerization potential range is -0.5 to 0.5 V, the scan rate is 50 to 100 mV / s, the cyclic scan is 10 to 20 times, the electrolyte is 0.01 M PBS, pH = 7.4, containing 5 to 8 mM dopamine and 20 to 25 mM ionic liquid.
8. The method for detecting amyloid peptide Aβ as described in claim 1 1-42 The method for fabricating a miniature electrochemical sensor is characterized by, Step 7) involves eluting the encapsulated amyloid peptide Aβ. 1-42 The template was eluted with PBS solution containing methanol for 60–120 minutes, with a methanol to PBS volume ratio of 1:
20.
9. An amyloid-detecting polypeptide Aβ prepared by the preparation method according to any one of claims 1-8 1-42 Miniature electrochemical sensors.
10. A detection method for amyloid peptide Aβ as described in claim 9 1-42 Applications of miniature electrochemical sensors.