Preparation method and application of MoS2-Ti / Au modified PET thin film electrode molecularly imprinted electrochemical sensor
By combining MoS2-Ti/Au modified PET thin film electrodes with molecular imprinting technology, the problems of low sensitivity and high cost of existing electrochemical sensors were solved, and high-sensitivity and high-stability serotonin detection was achieved, which is suitable for commercial applications.
Patent Information
- Application Number
- CN202411862727.0
- Authority / Receiving Office
- CN · China
- Patent Type
- Patents(China)
- Current Assignee / Owner
- Filing Date
- 2024-12-17
- Publication Date
- 2025-09-23
- Estimated Expiration
- 2044-12-17
AI Technical Summary
Existing molecular imprinting electrochemical sensors have problems such as low sensitivity, few effective sites, nonspecific adsorption and slow elution rate, and traditional electrode materials are expensive and complex to manufacture.
A MoS2-Ti/Au modified PET thin film electrode was used. Ti and Au were sputtered on the PET film and MoS2 thin film was coated. Combined with molecular imprinting technology, Prussian blue solution and pyrrole solution were used for electropolymerization to form a molecular imprinting film, which was then deposited on the electrode surface by cyclic voltammetry. After elution, a MoS2-Ti/Au modified PET thin film electrode molecular imprinting electrochemical sensor was prepared.
The sensitivity and stability of the sensor are improved, the sensing performance is enhanced, and high reproducibility, stability and selective detection of serotonin are achieved. The preparation process is simple and low-cost, making it suitable for fast and accurate commercial applications.
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Figure CN119688799B_ABST
Abstract
Description
Technical Field
[0001] The present invention relates to the field of molecular imprinting electrochemical sensors, and in particular to a preparation method and application of a MoS2-Ti / Au modified PET thin film electrode molecular imprinting electrochemical sensor. Background Art
[0002] As a typical transition metal disulfide material, MoS2 is one of the most widely studied and applied graphene-like nanomaterials. MoS2 possesses exceptional mechanical properties, excellent biocompatibility, outstanding electrochemical catalytic performance, and a high specific surface area, enabling the rapid development of MoS2-based sensors. In electrochemical sensing, MoS2 can act as an electron transfer medium or electrocatalyst, playing a role in signal amplification. Electrochemical sensing is an analytical method that analyzes the composition of a substance by monitoring changes in the electrochemical signal of a sensor element. Traditional electrochemical sensors typically use glassy carbon electrodes or indium tin oxide (ITO) glass electrodes. While these electrodes offer excellent performance, their fabrication and pretreatment are complex and costly. In contrast, ultrathin plastic substrates such as polyethylene terephthalate (PET) are ideal flexible platforms for electrode fabrication due to their low cost, excellent thermal strength, good ink compatibility, and mechanical resilience after repeated bending and torsion.
[0003] Molecular imprinting technology (MIT), also known as template imprinting technology, involves the artificial synthesis of polymers that are highly selective for a specific target molecule (template molecule). Molecularly imprinted polymers (MIPs) produced using this technique possess a functional group arrangement complementary to the template molecule and a specific pore size and shape, resulting in high recognition of the template molecule. The high stability and specificity of MIPs allow them to be tailor-made for any molecule, resulting in low production costs and ease of large-scale production. Electrochemical biosensors based on molecularly imprinted polymers (MITs) combine many of the advantages of both MIPs and electrochemical biosensors, such as high selectivity, high sensitivity, chemical and mechanical stability, reusability, low detection limits, simple preparation, and low cost, and therefore have attracted considerable attention in electrochemical sensor fabrication. However, as polymer membrane materials, MIPs have poor conductivity, which limits their application in electrochemical sensing. Currently reported molecularly imprinted electrochemical sensors suffer from low sensitivity, limited effective sites, nonspecific adsorption, and slow elution rates. To overcome these shortcomings and improve sensor conductivity, the selection of conductive substrates with high surface area structures as components of sensor devices has attracted widespread attention. Fabricating MIPs on high-surface-area materials can create numerous recognition sites, thereby increasing the accumulation of analytes on the electrode surface. Therefore, the development of rapid, accurate, and sensitive detection devices and methods is of great significance. Summary of the Invention
[0004] The purpose of the present invention is to provide a preparation method and application of a MoS2-Ti / Au modified PET thin film electrode molecular imprinting electrochemical sensor.
[0005] The present invention is achieved through the following technical solutions:
[0006] The present invention relates to a method for preparing a MoS2-Ti / Au modified PET thin film electrode molecular imprinting electrochemical sensor, which is characterized by comprising the following steps:
[0007] Step 1, preparation of MoS2-Ti / Au electrode material: slice the PET film, clean and dry it, sputter Ti and Au metals, and coat the MoS2 film on the electrode surface;
[0008] Step 2, prepare Prussian blue solution: mix FeCl3, K3[Fe(CN)6], KCl, and PBS solution and stir;
[0009] Step 3, prepare pyrrole solution: dissolve 100 μM monopyrrole solution (concentration ≥ 98%) in 5 mL of ethanol and stir until fully dissolved;
[0010] Step 4, preparing a molecular polymerization solution: dissolve the template molecule in 5 mL of water, add PBS solution, then add Prussian blue solution and pyrrole solution, stir, let stand, and collect the supernatant to prepare a molecular polymerization solution MIP solution;
[0011] Step 5, electropolymerization reaction: immersing the MoS2-Ti / Au electrode material in a molecular polymerization solution, depositing it on the surface of the electrode substrate using cyclic voltammetry to form a molecular imprinted film, and polymerizing to obtain a polymerized MIP electrode;
[0012] S6, eluting the polymerized MIP electrode to wash away the template molecules on the molecularly imprinted membrane to obtain a MoS2-Ti / Au modified PET thin film electrode molecularly imprinted electrochemical sensor.
[0013] Preferably, in step 1, the specific steps of preparing the MoS2-Ti / Au electrode material are:
[0014] (1) The PET film was sliced, ultrasonically cleaned in an ethanol solution, soaked in deionized water, and dried with N2;
[0015] (2) Using magnetron sputtering technology, Ti and Au metals are sputtered sequentially in the sputtering chamber;
[0016] (3) Use a micropipette to drop the MoS2 suspension onto the surface of the PET electrode containing Ti / Au, and let it stand at room temperature to fully dry to form a uniform film on the surface of the PET electrode.
[0017] Preferably, the thicknesses of the Ti and Au metals are 5 nm and 40 nm, respectively.
[0018] Preferably, in step 2, the Prussian blue solution is prepared as follows: first, 10 mM FeCl3, 10 mM K3[Fe(CN)6], 10 mM KCl, and 5 mM PBS solution are mixed and stirred at 400 rpm until uniformly prepared.
[0019] Preferably, in step 3, the stirring is carried out using a magnetic stirrer.
[0020] Preferably, in step 4, the concentration ratio of the Prussian blue solution, the pyrrole solution, and the template molecule is 1:10:1; and the stirring is performed using a magnetic stirrer for 40 minutes.
[0021] Preferably, in step 5, the electropolymerization reaction is carried out in a three-electrode system, the working electrode is a MoS2-Ti / Au electrode, the counter electrode is a graphite electrode, and the reference electrode is a silver / silver chloride electrode; the deposited deposition liquid is a molecular imprinting polymerization solution; after the polymerization is completed, the electrodes are rinsed with water and left to be eluted.
[0022] Preferably, in step 6, the specific method of elution is: immersing the polymerized MIP electrode in an elution solvent PBS buffer solution, eluting with SWV at different frequencies in the potential range of -0.3 to 1.1 V, and the number of elutions is 8 to 15 times.
[0023] The present invention also relates to the application of the aforementioned MoS2-Ti / Au modified PET thin film electrode molecular imprinting electrochemical sensor, and the aforementioned prepared MoS2-Ti / Au modified PET thin film electrode molecular imprinting electrochemical sensor is used for selective detection of serotonin.
[0024] Preferably, the process of detecting serotonin is as follows: immersing the polymerized MIP electrode in a PBS buffer solution, sequentially adding serotonin of different concentrations, and detecting the electrochemical response thereof using the SWV method.
[0025] The present invention has the following advantages:
[0026] (1) The MoS2-Ti / Au modified PET thin film electrode prepared by the method of the present invention not only increases the active catalytic sites by co-modifying the electrode with MoS2 and Ti / Au, but also improves the conductivity through the synergistic effect of the two, thereby enhancing the sensitivity and stability of the sensor and improving the sensing performance.
[0027] (2) The present invention is based on a MoS2-Ti / Au modified PET thin film electrode, which is used to prepare a molecular imprinting electrochemical sensor that can detect different substances, such as serotonin, based on different template molecules; the sensor has high reproducibility, stability and selectivity; the sensor is fast, efficient and accurate, and is easy to commercialize, with a simple preparation process and convenient detection operation.
[0028] (3) The present invention uses pyrrole (Py) as a functional monomer and uses cyclic voltammetry to directly polymerize Py and template molecules in a polymerization mixture on the surface of a MoS2-Ti / Au modified PET thin film electrode to entrap the template molecules in the polymer backbone. Subsequently, after removing the template molecules from the polypyrrole (PPy) matrix, the resulting MIP membrane can selectively recognize the target molecules upon rebinding. Since PPy has good electrical conductivity, the preparation process is simple and environmentally friendly, and polypyrrole has biocompatibility and high selective permeability, it is It has become an ideal material for preparing sensitive membranes of sensors; the preparation process of this method is simple and can be achieved only by performing cyclic voltammetry scanning in a solution of functional monomers and template molecules; the preparation device is simple and easy to control the conditions, and the thickness of the polymer film can be precisely controlled to ensure uniform film thickness and high reproducibility; the polymer film has good rigidity, and after the template molecules are removed, the imprinted holes are not easily deformed, ensuring repeatability; in addition, the sensor structure is stable, the imprinted layer is not easy to fall off during the elution process, and it is easy to recombine with the template molecules, which can accurately and quickly determine the content of low concentrations of the analyte.
[0029] (4) The MoS2-Ti / Au modified PET thin film electrode molecular imprinting electrochemical sensor provided by the present invention is not only convenient, fast, efficient, but also low-cost. It overcomes the problems of existing detection technologies such as insufficient specificity, low sensitivity, long detection cycle, and complex operation. In addition, the sensor can be applied to the determination of serotonin content in the human body. BRIEF DESCRIPTION OF THE DRAWINGS
[0030] Figure 1 The SEM comparison images of the MoS2-Ti / Au modified PET thin film electrode molecular imprinting electrochemical sensor before and after elution according to the present invention are shown; a and b are low-magnification and high-magnification SEM images of the sensor before elution, respectively; c and d are low-magnification and high-magnification SEM images of the sensor after elution, respectively;
[0031] Figure 2 Detection curves of the MoS2-Ti / Au modified PET thin film electrode molecular imprinted electrochemical sensor before and after elution and during the elution process involved in the present invention; wherein a is a serotonin elution process curve, and b is a test curve before and after serotonin elution;
[0032] Figure 3 The figure shows the linear curve of the MoS2-Ti / Au modified PET thin film electrode molecular imprinted electrochemical sensor for serotonin detection. In particular, a is the SWV response curve of the sensor to serotonin at different serotonin concentrations; b is the relationship curve between serotonin concentration and peak current.
[0033] Figure 4 This is a diagram showing the specific evaluation of the MoS2-Ti / Au modified PET thin film electrode molecular imprinting electrochemical sensor for serotonin involved in the present invention. DETAILED DESCRIPTION
[0034] The present invention will be described in detail below with reference to specific embodiments. It should be noted that the following embodiments are only for further explanation of the present invention, but the protection scope of the present invention is not limited to the following embodiments. Example
[0035] This embodiment relates to a method for preparing a MoS2-Ti / Au modified PET thin film electrode molecular imprinting electrochemical sensor, comprising the following steps:
[0036] Step 1, preparation of MoS2-Ti / Au electrode material: PET film was sliced, cleaned, and dried with N2. Ti and Au were then deposited on the PET film using magnetron sputtering technology. The thickness of Ti and Au was 10 nm and 40 nm, respectively. Finally, a MoS2 film was formed on the electrode surface to obtain a MoS2-Ti / Au electrode.
[0037] Step 2, prepare Prussian blue solution: weigh 100 mg FeCl3, 100 mg K3[Fe(CN)6], and 100 mg KCl in a beaker, add 50 mL PBS solution, and stir for 40 minutes to mix thoroughly;
[0038] Step 3, prepare pyrrole solution: dissolve 100 µL of ≥98% monopyrrole solution in 5 mL of ethanol;
[0039] Step 4, prepare the molecular polymerization solution: weigh 43 mg of serotonin and dissolve it in 5 mL of water. Pour the solution into a beaker containing 35 mL of PBS solution. Prussian blue solution and pyrrole solution are then poured into the beakers to prepare the molecular polymerization solution.
[0040] Step 5, electropolymerization reaction: immersing the MoS2-Ti / Au electrode material treated in step 1 into the molecular polymerization solution obtained in step 4, and performing electropolymerization treatment by cyclic voltammetry to form a molecular imprinted film on the surface of the PET film electrode to obtain a polymerized MIP electrode;
[0041] The specific steps are as follows: In a three-electrode system, a MoS2-Ti / Au electrode is used as the working electrode, a graphite electrode is used as the counter electrode, and a silver / silver chloride electrode is used as the reference electrode; a molecular imprinted film, i.e., a polymerized MIP electrode, is formed on the surface of the MoS2-Ti / Au electrode. In this embodiment, the number of scan cycles is 20 and the scan rate is 25 mV / s;
[0042] Step 6: Elution of the polymerized MIP electrode to remove the template molecules on the molecularly imprinted membrane, yielding a 5-HT molecularly imprinted membrane-modified PET thin film electrode, i.e., the eluted MIP electrode. The specific steps are as follows: immersing the polymerized MIP electrode in a PBS solution as the elution solvent, using a three-electrode system with the polymerized MIP electrode as the working electrode, a graphite electrode as the counter electrode, and a silver / silver chloride electrode as the reference electrode. Elution is performed using the SWV method, with parameters set at a potential range of -0.3 to 1.1 V and a frequency of 15 Hz. After elution, the electrode surface is rinsed with pure water, yielding a MoS2-Ti / Au-modified PET thin film electrode molecularly imprinted electrochemical sensor.
[0043] like Figure 1 As shown, Figures a and b show the SEM images of the molecularly imprinted electrochemical sensor before elution; Figures c and d show the SEM images after elution. Figure 1 As can be seen in the figure, the sample morphology is spherical and relatively regular. A comparison reveals that before elution, the sample surface contained many tiny particles. After elution, these particles were removed, the surface roughness decreased, and more vacancies were exposed. This is because the template molecules left cavities and imprinted sites on the electrode after elution, providing conditions for subsequent selective adsorption.
[0044] A MoS2-Ti / Au-modified PET thin film electrode was used as the working electrode of a molecularly imprinted electrochemical sensor, along with a graphite electrode as the counter electrode and silver / silver chloride as the reference electrode. Detection was performed using the SWV method within a voltage range of 0–0.6 V at a frequency of 60 Hz. The SWV method was also used for elution. After elution, the electrode surface was rinsed with pure water, completing the sensor preparation.
[0045] Figure 2 The changes in the elution process of the molecularly imprinted electrochemical sensor made of MoS2-Ti / Au modified PET thin film electrode and the curves before and after elution. Figure 2Panel a shows the curve during the elution process. A clear peak begins to appear as the number of elutions increases. The initial decrease in peak current is due to the elution of some substances from the polymer membrane, including the 5-HT template molecule. After a certain number of elutions, the curve begins to rise, indicating that more template molecules have been eluted. The imprinted membrane at the hole sites covers the electrode surface, promoting electron transfer, leading to a corresponding increase in peak current. Elution is complete when the peak value stabilizes. Figure 2 Figure b shows the test curves before and after elution. No obvious peak was observed before elution, but an obvious peak appeared after elution, and the peak value increased significantly after elution. The larger the current value, the more cavities there are on the imprinted membrane, which once again verifies that the template molecules were eluted.
[0046] In a three-electrode system, the eluted molecular imprinted electrode was used as the working electrode, the counter electrode was a graphite electrode, and the reference electrode was a silver / silver chloride electrode. The electrodes were electrochemically characterized by square wave voltammetry. Figure 3 Figure a is the square wave voltammogram of the imprinted electrode under different concentrations of serotonin; when constructing the calibration curve, different concentrations of serotonin are used as the horizontal axis and the corresponding peak current is used as the vertical axis.
[0047] like Figure 3 As shown in the figure, by comparison, it can be verified that after elution, the imprinted electrode surface leaves holes that specifically bind to the molecular structure of serotonin. As the concentration of serotonin increases, the imprinted holes are gradually filled, resulting in a decrease in the effective probe ion concentration reaching the electrode surface, a decrease in the electrical signal, and a decrease in the peak current. When the serotonin concentration reaches a certain value, the peak current no longer changes, which may be because the imprinted membrane holes on the electrode have been completely filled. A linear fit is performed on the serotonin concentration and the peak current value. Figure 3 b in the figure represents the linear relationship between the peak current and the concentration of serotonin in the range of 0.05 to 6 µM. The linear equation is I 五羟色胺 = -7.21C + 172 (R² = 0.9920).
[0048] To verify the selectivity and anti-interference ability of the molecularly imprinted electrochemical sensor of the present invention, dopamine, epinephrine, glucose and sodium chloride were selected as interfering substances. The electrochemical responses of the sensor to serotonin and interfering substances were investigated in a PBS buffer solution with a pH value of 6.8 (the results are shown in Figure 2). Figure 4 The results showed that in the presence of interfering substances, the sensor's peak current response changed little, indicating poor selectivity. However, when serotonin was added, the difference in the sensor's current response was significantly higher than that of other interfering substances, demonstrating the sensor's high recognition and specificity for serotonin.
[0049] In summary, the present invention successfully fabricated a MoS2-Ti / Au-modified PET thin film electrode molecularly imprinted electrochemical sensor capable of rapidly and efficiently detecting the target serotonin. The MoS2-Ti / Au modification increased the sensor's conductivity, thereby enhancing its sensitivity and stability. Through the fixed modification of the template molecule and functional monomer, ultrasensitive and highly specific detection of serotonin, a neurological disease marker, was achieved. Furthermore, the sensor's simple preparation process and convenient detection operation combined with its rapidity, efficiency, and accuracy are beneficial for commercial applications.
[0050] The above describes the specific embodiments of the present invention. It should be understood that the present invention is not limited to the above specific embodiments, and those skilled in the art may make various variations or modifications within the scope of the claims, which do not affect the essence of the present invention.
Claims
1. A method for preparing a MoS2-Ti / Au modified PET thin film electrode molecularly imprinted electrochemical sensor, characterized in that: The following steps are involved: Step 1, preparation of MoS2-Ti / Au electrode material: slice the PET film, clean and dry it, sputter Ti and Au metals, and coat the MoS2 film on the electrode surface; Step 2, prepare Prussian blue solution: mix FeCl3, K3[Fe(CN)6], KCl, and PBS solution and stir; Step 3, prepare pyrrole solution: dissolve 100 µL of monopyrrole solution in 5 mL of ethanol and stir until fully dissolved; Step 4, preparing a molecular polymerization solution: dissolving the template molecule 5-hydroxytryptamine in 5 mL of water, adding PBS solution, then adding Prussian blue solution and pyrrole solution, stirring, letting it stand, and collecting the supernatant to obtain a molecular polymerization solution; Step 5, electropolymerization reaction: immersing the MoS2-Ti / Au electrode material in a molecular polymerization solution, depositing it on the surface of the electrode substrate using cyclic voltammetry to form a molecular imprinted film, and polymerizing to obtain a polymerized MIP electrode; Step 6: Elute the polymerized MIP electrode to remove the template molecules on the molecularly imprinted membrane, thereby obtaining a MoS2-Ti / Au modified PET thin film electrode molecularly imprinted electrochemical sensor.
2. The method for preparing a MoS2-Ti / Au modified PET thin film electrode molecularly imprinted electrochemical sensor according to claim 1, characterized in that: In step 1, the specific steps of preparing the MoS2-Ti / Au electrode material are: (1) Slice the PET film, clean it ultrasonically in an ethanol solution, soak it in deionized water, and blow dry it with N2; (2) Using magnetron sputtering technology, Ti and Au metals are sputtered sequentially in the sputtering chamber; (3) Use a micropipette to drop the MoS2 suspension onto the surface of the PET electrode containing Ti / Au, and let it stand at room temperature to fully dry to form a uniform film on the surface of the PET electrode.
3. The method for preparing a MoS2-Ti / Au modified PET thin film electrode molecularly imprinted electrochemical sensor according to claim 2, characterized in that: The thicknesses of the Ti and Au metals are 5 nm and 40 nm respectively.
4. The method for preparing a MoS2-Ti / Au modified PET thin film electrode molecularly imprinted electrochemical sensor according to claim 1, characterized in that: In step 2, the Prussian blue solution is prepared as follows: first, 10 mM FeCl3, 10 mM K3[Fe(CN)6], 10 mM KCl, and 5 mM PBS solution are mixed and stirred at 400 rpm.
5. The method for preparing a MoS2-Ti / Au modified PET thin film electrode molecularly imprinted electrochemical sensor according to claim 1, characterized in that: In step 3, the stirring is carried out using a magnetic stirrer.
6. The method for preparing a MoS2-Ti / Au modified PET thin film electrode molecularly imprinted electrochemical sensor according to claim 1, characterized in that: In step 4, the concentration ratio of the Prussian blue solution, the pyrrole solution, and the template molecule is 1:10:1; and the stirring is performed using a magnetic stirrer for 40 minutes.
7. The method for preparing a MoS2-Ti / Au modified PET thin film electrode molecularly imprinted electrochemical sensor according to claim 1, characterized in that: In step 5, the electropolymerization reaction is carried out in a three-electrode system, the working electrode is a MoS2-Ti / Au electrode, the counter electrode is a graphite electrode, and the reference electrode is a silver / silver chloride electrode; the deposited deposition solution is a molecular imprinting polymerization solution.
8. The method for preparing a MoS2-Ti / Au modified PET thin film electrode molecularly imprinted electrochemical sensor according to claim 1, characterized in that: In step 6, the specific elution method is: immersing the polymerized MIP electrode in a PBS buffer solution, eluting by square wave voltammetry at different frequencies in the potential range of -0.3 to 1.1 V, and eluting 8 to 15 times.
9. An application of a MoS2-Ti / Au modified PET thin film electrode molecular imprinting electrochemical sensor, characterized in that: The MoS2-Ti / Au modified PET thin film electrode molecular imprinting electrochemical sensor prepared according to claim 1 is used for selective detection of serotonin.
10. The use of the MoS2-Ti / Au modified PET thin film electrode molecularly imprinted electrochemical sensor according to claim 9, characterized in that: The process of detecting serotonin is as follows: immersing the polymerized MIP electrode of claim 1 in a PBS buffer solution, sequentially adding serotonin of different concentrations, and detecting its electrochemical response using the SWV method.