Organic electrochemical transistor of molecularly imprinted semiconductor channel, preparation method and sensor
By electropolymerizing molecular imprinting polymers on the surface of semiconductor channels of organic electrochemical transistors to form molecular imprinting films, the problems of low-cost and large-scale production in the prior art are solved, and specific recognition and high-sensitivity sensing of target molecules are achieved.
Patent Information
- Application Number
- CN202411935813.X
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2024-12-26
- Publication Date
- 2025-04-04
AI Technical Summary
The prior art is difficult to achieve low-cost, large-scale production of organic electrochemical transistors, especially when traditional silicon-based OECT costs high and dimensional accuracy cannot meet the needs of traditional gate modification OECT.
Using a screen-printed electrode as a substrate, a molecular imprinting film is formed by electrically polymerizing the molecular imprinting polymer in the transistor semiconductor channel to achieve specific recognition of the target molecule. The method includes obtaining screen-printed electrodes, spin-coating PEDOT, electropolymerizing molecular imprinting films, and removing template molecules by ultrasound for specific identification.
It realizes low-cost and high-sensitivity organic electrochemical transistors, suitable for biosensing, environmental monitoring and other fields, and is easy to produce on a large scale.
Smart Images
Figure CN119757497A_ABST
Abstract
Description
Technical Field
[0001] The invention belongs to the field of biochemical sensors, and relates to an organic electrochemical transistor with a molecular imprinted semiconductor channel and a preparation method thereof, as well as a sensor based on the organic electrochemical transistor. Background Art
[0002] Organic electrochemical transistor (OECT) is based on the principle of field effect signal amplification, and has the characteristics of low power consumption, high sensitivity, and integration. It is widely used in biosensing and environmental detection of glucose, protein, DNA and RNA. The realization of OECT selectivity is usually based on the specific modification of the gate, and common ones include molecular imprinted polymers, nucleic acid aptamers, antigen antibodies, etc. Among them, molecular imprinted polymers (MIPs) have simple preparation methods, low cost, high mechanical strength, good stability, and excellent molecular recognition ability. The construction of molecular imprinted OECT is expected to achieve highly specific biosensing and environmental sensing.
[0003] Traditional silicon-based OECTs are expensive, making it difficult to achieve low-cost, large-scale production. Flexible screen-printed electrodes are low-cost and usually consist of gold electrodes, carbon electrodes, and Ag / AgCl reference electrodes. They are easy to scale up, but their dimensional accuracy cannot meet the requirements of traditional gate-modified OECTs. Summary of the invention
[0004] In view of this, the purpose of the present invention is to provide a molecular imprinted semiconductor channel organic electrochemical transistor, a preparation method and a sensor, so as to achieve the scale-up of OECT at low cost and use it in the fields of biosensing, environmental monitoring and so on.
[0005] To achieve the above object, one aspect of the present invention provides a molecular imprinted semiconductor channel organic electrochemical transistor, which includes a screen-printed electrode, a semiconductor channel formed between a working electrode and a counter electrode of the screen-printed electrode, and a molecular imprinted film formed on the surface of the semiconductor channel. The working electrode, the counter electrode, and the reference electrode of the screen-printed electrode serve as the source, the drain, and the gate of the organic electrochemical transistor, respectively.
[0006] The molecular imprinted film is formed by electropolymerizing molecular imprinted polymers on the surface of semiconductor channels.
[0007] Another aspect of the present invention provides a method for preparing a molecularly imprinted semiconductor channel organic electrochemical transistor, the method comprising:
[0008] Obtain a screen-printed electrode, and use a plasma cleaning machine to perform hydrophilic treatment on the screen-printed electrode; wherein the working electrode and the counter electrode of the screen-printed electrode are both made of carbon, and the reference electrode is made of Ag / AgCl;
[0009] PEDOT was spin-coated on the working electrode and counter electrode of the screen-printed electrode using a spin coater and then annealed at 180 °C in a nitrogen atmosphere for one hour;
[0010] The electropolymerization solution of molecular imprinting polymer is prepared, the screen-printed electrode with spin-coated PEDOT is immersed in the electropolymerization solution, and a layer of molecular imprinting film is electropolymerized by cyclic voltammetry;
[0011] The template molecules in the molecular imprinting membrane are removed by ultrasound. After the template molecules are removed, imprinting cavities are generated in the molecular imprinting membrane that match the size and shape of the template molecules and have complementary functional groups, thereby achieving specific recognition of the template molecules.
[0012] Another aspect of the present invention provides a sensor, which includes a signal collector, a USB converter and an organic electrochemical transistor, wherein the organic electrochemical transistor is connected to the signal collector via the USB converter, wherein the signal collector is a current signal collector.
[0013] The beneficial effect of the present invention is that the organic electrochemical transistor proposed by the present invention uses a screen-printed electrode as a matrix, and can achieve specific recognition of target molecules by electropolymerizing molecular imprinted polymers in the semiconductor channel of the transistor. The organic electrochemical transistor has a simple structure, low production cost, and is easy to mass produce, and can be widely used in the fields of biosensing, environmental monitoring, food testing, etc.
[0014] Other advantages, objectives and features of the present invention will be described in the following description to some extent, and to some extent, will be obvious to those skilled in the art based on the following examination and study, or can be taught from the practice of the present invention. The objectives and other advantages of the present invention can be realized and obtained through the following description. BRIEF DESCRIPTION OF THE DRAWINGS
[0015] In order to make the purpose, technical solutions and advantages of the present invention more clear, the present invention will be described in detail below in conjunction with the accompanying drawings, wherein:
[0016] Figure 1 A schematic diagram of the working principle of an organic electrochemical transistor provided by one embodiment of the present invention;
[0017] Figure 2 Schematic diagram of the preparation process of organic electrochemical transistors;
[0018] Figure 3The transfer curve of the organic electrochemical transistor for detecting different concentrations of PFOA;
[0019] Figure 4 Schematic diagram of specificity comparison of organic electrochemical transistors;
[0020] Figure 5 PFOA spike test results for different water bodies. DETAILED DESCRIPTION
[0021] The following describes the embodiments of the present invention by specific examples, and those skilled in the art can easily understand other advantages and effects of the present invention from the contents disclosed in this specification. The present invention can also be implemented or applied through other different specific embodiments, and the details in this specification can also be modified or changed in various ways based on different viewpoints and applications without departing from the spirit of the present invention. It should be noted that the illustrations provided in the following embodiments only illustrate the basic concept of the present invention in a schematic manner, and the following embodiments and features in the embodiments can be combined with each other without conflict.
[0022] One embodiment of the present invention proposes an organic electrochemical transistor with a molecular imprinted semiconductor channel, which can realize target molecule recognition and transconductance regulation of the organic electrochemical transistor, and can realize the scale of OECT at low cost. The organic electrochemical transistor uses a screen-printed electrode as a substrate, and the working electrode (WE) and the counter electrode (CE) of the screen-printed electrode are used as the source (S) and drain (D) of the OECT, respectively, and the reference electrode (RE) is used as the gate (G) of the OECT. After a layer of PEDOT semiconductor is modified on the surface of the S and D electrodes, it serves as a semiconductor channel between the S and D electrodes, and then a layer of molecular imprinted polymer is electropolymerized on the surface of the semiconductor channel, wherein the cavity of the molecular imprinted film is a specific recognition site for the target analyte.
[0023] like Figure 1 As shown, the basic working principle of the organic electrochemical transistor is:
[0024] The organic electrochemical transistor with molecular imprinted semiconductor channel forms an adsorption layer with specific recognition of target molecules by electropolymerizing molecular imprinted polymer on the channel surface. When different concentrations of target molecules are adsorbed, the imprinted holes inside the molecular imprinted polymer are filled to a corresponding degree, thereby affecting the migration ability of ions from the electrolyte to the semiconductor layer when the organic electrochemical transistor is working. This characteristic is manifested in the macroscopic aspect that the organic electrochemical transistor in the traditional OECT working mode changes with the increase of V GS The voltage increase, I DS The current gradually decreases, but due to the influence of the molecular imprinting layer, I DSThe decrease of I will be suppressed, and with the increase of the concentration of target molecules, the number of cavities of molecular imprinting polymers decreases, DS The reduction rate is further suppressed. Therefore, when the concentration of the molecular imprinting adsorbed target molecules is different, the switching ability of the organic electrochemical transistor of the molecular imprinting semiconductor channel is different, resulting in changes in its final output signal. DS The rate of change should be linearly related to the change in the concentration of the target analyte.
[0025] This transistor can effectively act on all target molecules that can form molecular imprinting polymers, and is mainly used in biosensing, environmental monitoring, food testing and other fields.
[0026] Another embodiment of the present invention provides a method for preparing a molecularly imprinted semiconductor channel organic electrochemical transistor, such as Figure 2 As shown, the method includes:
[0027] 1. Obtain a screen-printed three-electrode, where the working electrode and the counter electrode are made of carbon, and the reference electrode is made of Ag / AgCl.
[0028] 2. Use a plasma cleaning machine to perform hydrophilic treatment on the screen-printed electrode, control the pressure to 30 Pa, the power to 10%, and the treatment for 30 seconds.
[0029] 3. Spin coat PEDOT on the working electrode and counter electrode of the screen-printed electrode using a spin coater for 30 seconds at a speed of 7000 rp / m; then anneal at 180°C in a nitrogen atmosphere for 1 hour. This step prepares a traditional OECT with Ag or AgCl as the gate.
[0030] 4. Prepare an electropolymerization solution of perfluorooctanoic acid (PFOA) and o-phenylenediamine (o-PD), wherein the concentration of PFOA is 0.001M, the concentration of o-PD is 0.01M, and the solvent is a mixture of sodium acetate buffer and methanol in a ratio of 2:1; immerse the PEDOT-loaded screen-printed electrode in the electropolymerization solution, and use cyclic voltammetry to electropolymerize a layer of PFOA imprinted film.
[0031] 5. Use a 1:1 mixture of sodium acetate buffer and methanol to ultrasonically remove the template molecules in the PFOA imprinted membrane. After removing the template molecules, an imprinted cavity that completely matches the size and shape of the template molecules and has complementary functional groups will be generated in the PFOA imprinted membrane, thereby generating specific recognition of the template molecules.
[0032] Another embodiment of the present invention provides a sensor, which includes a USB converter, a collection instrument, and an organic electrochemical transistor provided by the above embodiment. Wherein, the gate, source, and drain electrodes of the organic electrochemical transistor are all connected to the USB converter, and the USB converter is further connected to the collection instrument. Its working process is: the surface of the gate, source, and drain is completely covered with the sample for adsorption, and after the adsorption is completed, the surface is loaded with PBS buffer, and the printed electrode of the transistor is connected to the instrument through the USB converter to collect signals. The gate acts to apply voltage to control the injection of ions into the semiconductor channel, and the collection instrument collects the current signal between the source and the drain in the process, wherein the current between the source and the drain is continuously reduced during the increase of the gate voltage, and when the concentration of the target molecule PFOA is high, the switching ability decreases, so the final output current intensity is high.
[0033] The PFOA sample was loaded onto the sensor organic electrochemical transistor for specific adsorption, and then the sample was eluted. A certain amount of 0.1M PBS buffer was loaded on the surface, and the OECT signal was detected.
[0034] like Figure 3 The figure shows the transfer curve of the organic electrochemical transistor for different concentrations of PFOA detection. It can be seen that as the PFOA concentration increases, the cavity of the molecular imprinted semiconductor material is filled with PFOA, and the migration of ions through the molecular imprinted membrane under the action of the electric field is suppressed, resulting in an increase in the drain-source current. The linear correlation of PFOA detection was calculated by calculating the rate of change of the difference between the drain-source current at 1V and the drain-source current at 0 concentration, where R 2 It reached 0.9929, indicating that the drain-source current had an excellent linear correlation with the PFOA concentration.
[0035] Figure 4 The results show that different pollutants -12 From the current response at different concentrations of M, it can be seen that the organic electrochemical transistor has strong specificity. Figure 5 The figure shows the PFOA spike test carried out in different water bodies. It can be seen that its recovery rate meets the actual application requirements.
[0036] Finally, it should be noted that the above embodiments are only used to illustrate the technical solution of the present invention rather than to limit it. Although the present invention has been described in detail with reference to the preferred embodiments, those skilled in the art should understand that the technical solution of the present invention can be modified or replaced by equivalents without departing from the purpose and scope of the technical solution, which should be included in the scope of the claims of the present invention.
Claims
1. A molecularly imprinted semiconductor channel organic electrochemical transistor, characterized in that: It includes a screen-printed electrode, a semiconductor channel formed between a working electrode and a counter electrode of the screen-printed electrode, and a molecular imprinting film formed on the surface of the semiconductor channel; wherein the working electrode, counter electrode and reference electrode of the screen-printed electrode serve as the source, drain and gate of the organic electrochemical transistor respectively.
2. The organic electrochemical transistor according to claim 1, characterized in that The molecular imprinted film is formed by electropolymerizing a molecular imprinted polymer on the surface of the semiconductor channel.
3. A method for preparing a molecularly imprinted semiconductor channel organic electrochemical transistor, characterized in that: The method includes: Obtain a screen-printed electrode, and use a plasma cleaning machine to perform hydrophilic treatment on the screen-printed electrode; wherein the working electrode and the counter electrode of the screen-printed electrode are both made of carbon, and the reference electrode is made of Ag / AgCl; PEDOT was spin-coated on the working electrode and counter electrode of the screen-printed electrode using a spin coater and then annealed at 180 °C in a nitrogen atmosphere for one hour; The electropolymerization solution of molecular imprinting polymer is prepared, the screen-printed electrode with spin-coated PEDOT is immersed in the electropolymerization solution, and a layer of molecular imprinting film is electropolymerized by cyclic voltammetry; The template molecules in the molecular imprinting membrane are removed by ultrasound. After the template molecules are removed, imprinting cavities are generated in the molecular imprinting membrane that match the size and shape of the template molecules and have complementary functional groups, thereby achieving specific recognition of the template molecules.
4. A sensor, comprising a signal collector and a USB converter, characterized in that: It also includes the organic electrochemical transistor according to claim 1 or 2, wherein the organic electrochemical transistor is connected to the signal collector via the USB converter.
5. The sensor according to claim 4, characterized in that The signal collector is a current signal collector.