Chiral polypyrrole transistor, method for preparing the same and use thereof

Abstract

The application provides a chiral polypyrrole transistor and a preparation method and application thereof. The application generates polypyrrole nanowires with a chiral structure on the surface of a fiber monofilament in situ by the following steps: the fiber monofilament is made into a coil; a chiral small-molecule compound is blended with pyrrole monomers and water; the mixture is fully stirred; then the coil and an aqueous solution of an oxidizing agent are sequentially added; after in-situ polymerization, the chiral small-molecule compound is removed; and finally, a chiral polypyrrole transistor is obtained after assembly. Through the above method, the application can prepare polypyrrole nanowires with a chiral structure, effectively controls the structure of polypyrrole itself, and greatly improves the transconductance signal of the finally prepared chiral polypyrrole transistor. The preparation method provided by the application is simple and easy to control, the chiral polypyrrole transistor prepared by the method has excellent performance and good biocompatibility, and has a wide application prospect in the field of antibody detection.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of organic electrochemical transistors, in particular to a chiral polypyrrole transistor and a preparation method and application thereof. BACKGROUND

[0002] Organic electrochemical transistors (OECTs) are a kind of organic thin film transistors developed in the past three decades, which not only have the advantages of traditional organic thin film transistors, but also have the advantages of simple structure, low working voltage, and can work in a solution environment. In addition, the organic semiconductors used in organic electrochemical transistors usually have good biocompatibility, so they have been widely used in the detection of biochemical substances such as lactic acid, glucose, dopamine, DNA, bacteria and antigens.

[0003] Among various conductive polymers used for preparing organic electrochemical transistors, polypyrrole is a kind of polymer with high conductivity obtained by polymerization of pyrrole compounds. Its good environmental stability and excellent conductivity and biocompatibility make it show great application prospect in the field of biosensing, and thus has attracted extensive attention from researchers. At present, when preparing polypyrrole transistors, a fiber substrate is usually placed in a solution containing pyrrole monomers and oxidants, so as to synthesize polypyrrole in situ on the fiber substrate, and then the polypyrrole is assembled into a transistor. However, the transistors prepared by this method usually have low transconductance signals, which limits their practical application.

[0004] In order to improve the performance of polypyrrole transistors, existing researches mainly focus on the combination of graphene or carbon nanotubes on the surface of fiber substrates. For example, the patent with publication number CN108978189A provides a carbon nanotube / polypyrrole composite fiber, a preparation method thereof and application thereof in a transistor sensor. In this patent, carbon nanotubes are dispersed on a flexible fiber, and then pyrrole monomers are chemically polymerized in situ on the flexible fiber containing the coated carbon nanotubes. In this way, the good thermodynamic properties and conductivity of carbon nanotubes are utilized to form a bridge-like effect between the surface of the flexible fiber and the polypyrrole, so as to promote the growth of linear polypyrrole, and thus improve the performance of the transistor sensor. However, this method requires the additional use of carbon nanotubes or graphene, which increases the preparation cost, and can only promote the growth of polypyrrole in a linear manner to a certain extent, and it is difficult to effectively regulate the structure of the in-situ generated polypyrrole. The electrochemical performance of the prepared transistor still needs to be improved.

[0005] Therefore, it is necessary to design an improved preparation method of polypyrrole transistor to effectively regulate the structure of polypyrrole to solve the above problems. SUMMARY

[0006] In view of the defects of the prior art, the present application aims to provide a chiral polypyrrole transistor and a preparation method and application thereof. A chiral small molecule compound is introduced in the process of synthesizing polypyrrole, and is blended with pyrrole monomers, so that polypyrrole nanofibers with chiral structure are generated in situ on the surface of fiber filaments, and the transconductance signal of the finally prepared chiral polypyrrole transistor is greatly improved.

[0007] To achieve the above-mentioned purpose, the present application provides a preparation method of a chiral polypyrrole transistor, comprising the following steps:

[0008] S1, washing and drying fiber filaments, and uniformly winding them into a coil for standby;

[0009] S2, dissolving a chiral small molecule compound, adding pyrrole monomers and water under ice water bath conditions, adding the coil obtained in step S1 after sufficient stirring, adding an aqueous solution of an oxidizing agent after uniform stirring, and taking out the coil after a predetermined reaction time;

[0010] S3, washing the coil taken out in step S2, boiling and refluxing it in a mixed solution of ethanol and hydrochloric acid, taking out the coil and drying it, and obtaining a fiber with chiral polypyrrole nanowires loaded on the surface;

[0011] S4, assembling the fiber with chiral polypyrrole nanowires loaded on the surface obtained in step S3 with a gel electrolyte, and obtaining a chiral polypyrrole transistor.

[0012] As a further improvement of the present application, in step S2, the molar ratio of the chiral small molecule compound to the pyrrole monomers and the oxidizing agent is 1:(100-110):(100-110).

[0013] As a further improvement of the present application, in step S2, the predetermined time is 3-5 h.

[0014] As a further improvement of the present application, in step S3, the boiling and refluxing time is 5-15 min.

[0015] As a further improvement of the present application, in step S2, the concentration of the aqueous solution of the oxidizing agent is 1-5 mol / L, and the oxidizing agent is one of ferric nitrate nonahydrate, ferric chloride hexahydrate, ammonium persulfate or potassium persulfate.

[0016] As a further improvement of the present application, in step S1, the fiber filaments are one of polyester fiber, nylon fiber, aramid fiber, polyurethane fiber or cotton fiber.

[0017] As a further improvement of the present application, in step S2, the chiral small molecule compound is obtained by an amide reaction of a long-chain acyl chloride and an amino acid; the long-chain acyl chloride is one of dodecanoyl chloride, tetradecanoyl chloride, hexadecanoyl chloride and octadecanoyl chloride, and the amino acid is one of phenylalanine, alanine, phenylglycine, valine, leucine, glutamic acid and isoleucine.

[0018] As a further improvement of the present application, in step S4, the assembling process comprises the following steps:

[0019] Two fibers of a predetermined length are taken from the fibers with chiral polypyrrole nanowires loaded on the surface obtained in step S3, and are placed in parallel at a predetermined interval; then conductive silver paste is coated on both ends of the two fibers, and a gel electrolyte is added dropwise at a position of the two fibers where no conductive silver paste is coated, so that the gel electrolyte covers the two fibers, thereby obtaining a chiral polypyrrole transistor.

[0020] To achieve the above-mentioned object, the present application further provides a chiral polypyrrole transistor, which is prepared according to any one of the above technical solutions, comprising a fiber monofilament and chiral polypyrrole nanowires loaded on the surface of the fiber monofilament.

[0021] The present application further provides an application of the above-mentioned chiral polypyrrole transistor in the field of antibody detection.

[0022] The present application has the following advantages:

[0023] (1) The preparation method of the chiral polypyrrole transistor provided by the present application introduces a chiral small molecule compound into the process of synthesizing polypyrrole, and blends the chiral small molecule compound with pyrrole monomers, so that polypyrrole nanowires with chiral structures are generated in situ on the surface of the fiber monofilament, effective regulation of the structure of polypyrrole itself is realized, and the transconductance signal of the finally prepared chiral polypyrrole transistor is greatly improved, which has high practical application value.

[0024] (2) The present application introduces a chiral small molecule compound as a template, blends the chiral small molecule compound with pyrrole monomers, forms a spiral fiber aggregate by non-covalent bond interaction between the chiral small molecule compounds, and adsorbs the pyrrole monomers on the surface of the spiral fiber aggregate, so that after in-situ polymerization, the chiral small molecule compound is removed by boiling reflux in an ethanol and hydrochloric acid mixed solution, thereby obtaining polypyrrole nanowires with chiral structures. Compared with traditional spherical polypyrrole, the transistor prepared based on the chiral polypyrrole nanowires not only has higher stability and sensitivity, but also has extremely high transconductance signal, effectively solving the problem of low transconductance signal of traditional polypyrrole transistors.

[0025] (3) The preparation method of the chiral polypyrrole transistor provided by the application has simple process and is easy to control, and the chiral polypyrrole transistor prepared has excellent performance and good biocompatibility, and has wide application prospects in the field of antibody detection. BRIEF DESCRIPTION OF DRAWINGS

[0026] Figure 1 A flowchart for preparing the chiral polypyrrole transistor in Example 1.

[0027] Figure 2 A scanning electron microscope image of the fiber loaded with chiral polypyrrole nanowires prepared in Example 1, with a scale of 100 μm.

[0028] Figure 3 A scanning electron microscope image of the fiber loaded with chiral polypyrrole nanowires prepared in Example 1, with a scale of 100 nm.

[0029] Figure 4 A diffuse reflectance circular dichroism spectrum of the fiber loaded with chiral polypyrrole nanowires prepared in Example 1.

[0030] Figure 5 A scanning electron microscope image of the fiber loaded with polypyrrole prepared in Comparative Example 1, with a scale of 1 μm. DETAILED DESCRIPTION

[0031] In order to make the objects, technical solutions and advantages of the present application clearer, the present application will be described in detail below with reference to the drawings and specific embodiments.

[0032] Here, it should also be noted that, in order to avoid obscuring the present application due to unnecessary details, only structures and / or processing steps closely related to the solutions of the present application are shown in the drawings, and other details not closely related to the present application are omitted.

[0033] In addition, it should also be noted that the term "comprise", "include" or any other variant thereof is intended to cover non-exclusive inclusion, so that the process, method, article or equipment including a series of elements not only includes those elements, but also includes other elements not explicitly listed or inherent to such process, method, article or equipment.

[0034] To achieve the above object, the present application provides a preparation method of a chiral polypyrrole transistor, comprising the following steps:

[0035] S1, washing and drying the fiber monofilament, and uniformly winding it into a coil for standby;

[0036] S2, after the chiral small molecule compound is dissolved, pyrrole monomer and water are added under the condition of ice water bath, the coil obtained in step S1 is added after being fully stirred, the aqueous solution of oxidant is added after being uniformly stirred, the coil is taken out after a predetermined time of reaction;

[0037] S3, after the coil taken out in step S2 is washed, the coil is placed in a mixed solution of ethanol and hydrochloric acid for boiling reflux, the coil is taken out and dried, and a fiber with chiral polypyrrole nanowires loaded on the surface is obtained;

[0038] S4, the fiber with chiral polypyrrole nanowires loaded on the surface obtained in step S3 is assembled with a gel electrolyte, and a chiral polypyrrole transistor is obtained.

[0039] In step S1, the fiber monofilament is one of polyester fiber, nylon fiber, aramid fiber, polyamide fiber or cotton fiber.

[0040] In step S2, the chiral small molecule compound is obtained by amide reaction of long-chain acyl chloride and amino acid; the long-chain acyl chloride is one of dodecanoyl chloride, tetradecanoyl chloride, hexadecanoyl chloride and octadecanoyl chloride, and the amino acid is one of phenylalanine, alanine, phenylglycine, valine, leucine, glutamic acid and isoleucine; the molar ratio of the chiral small molecule compound to the pyrrole monomer and the oxidant is 1:(100-110):(100-110); the concentration of the aqueous solution of the oxidant is 1-5 mol / L, and the oxidant is one of ferric nitrate nonahydrate, ferric chloride hexahydrate, ammonium persulfate and potassium persulfate; the predetermined time is 3-5 h.

[0041] In step S3, the boiling reflux time is 5-15 min.

[0042] In step S4, the assembly process includes the following steps:

[0043] Two fibers of a predetermined length are taken out from the fiber with chiral polypyrrole nanowires loaded on the surface obtained in step S3, and are placed in parallel at a predetermined interval; then conductive silver paste is coated on both ends of the two fibers, and gel electrolyte is added dropwise at the part of the two fibers where no conductive silver paste is coated, so that the gel electrolyte covers the two fibers, and a chiral polypyrrole transistor is obtained.

[0044] The application also provides a chiral polypyrrole transistor prepared according to the above technical solution, which comprises a fiber monofilament and chiral polypyrrole nanowires loaded on the surface of the fiber monofilament. The chiral polypyrrole transistor can be used in the field of antibody detection.

[0045] The chiral polypyrole transistor provided by the present application, the preparation method thereof and the application thereof will be described below in combination with examples and comparative examples.

[0046] Example 1

[0047] The present example provides a preparation method of a chiral polypyrole transistor, and a preparation process diagram thereof is shown as Figure 1 The preparation method comprises the following steps:

[0048] S1, the PET fiber monofilament is first cleaned with dilute hydrochloric acid for 2 hours, then sequentially cleaned with water, acetone and ethanol for 20 minutes each time, and then dried at room temperature. Then, the fiber is uniformly wound on a plastic circle to form a fiber coil for storage.

[0049] S2, 0.32 mmol of chiral small molecule compound L-14PheCOOH is dissolved in 40 mL of anhydrous ethanol, 34 mmol of pyrrole monomer is added under ice water bath condition, and then 160 mL of water is added after stirring. After stirring for 2 minutes, the coil obtained in step S1 is added, and then stirred for 40 minutes. Then, 34 mmol of ferric chloride hexahydrate dissolved in 10 mL of deionized water is added dropwise as an oxidant. After 4 hours of reaction, the coil is taken out.

[0050] In the present example, the chiral small molecule compound L-14PheCOOH used is obtained by amide reaction of tetradecanoyl chloride and phenylalanine, and its molecular formula is as follows:

[0051]

[0052] S3, the coil taken out in step S2 is washed with ethanol and water for three times each, and then boiled and refluxed in a mixed solution of ethanol and hydrochloric acid with a volume ratio of 1:1 for 10 minutes. Then, the coil is taken out and vacuum dried at room temperature to obtain a fiber with chiral polypyrole nanowires loaded on the surface.

[0053] S4, two fibers with a length of 2 cm are taken from the fiber with chiral polypyrole nanowires loaded on the surface obtained in step S3, and the two fibers are placed in parallel with a spacing of 0.5 mm. Then, conductive silver paste is coated on both ends of the two fibers as the source and drain electrodes of the transistor gate electrode, and the middle part of the two fibers without conductive silver paste is used as the channel of the transistor. Gel electrolyte is added to the channel part to cover the two fibers, and a chiral polypyrole transistor is obtained.

[0054] In order to analyze the microstructure of the chiral polypyrole transistor prepared in the present example, the fiber with chiral polypyrole nanowires loaded on the surface obtained in step S3 is characterized, and scanning electron microscope images with scales of 100 μm and 100 nm are obtained, respectively as Figure 2 、 Figure 3As shown.

[0055] Depend on Figure 2 , Figure 3 It can be seen that a large number of polypyrrole nanowires are uniformly loaded on the surface of the fiber monofilaments, and these polypyrrole nanowires exhibit a left-handed helical structure. Based on the above preparation steps and performance characterization results, it can be seen that this embodiment successfully prepared chiral polypyrrole nanowires by introducing a chiral small molecule compound as a template, blending it with pyrrole monomers, utilizing the non-covalent bond interactions between the chiral small molecule compounds to form helical fiber aggregates, and adsorbing the pyrrole monomers onto their surface. After in-situ polymerization, the nanowires were boiled and refluxed in a mixed solution of ethanol and hydrochloric acid to remove the chiral small molecule compounds, thus achieving effective control over the structure of polypyrrole.

[0056] The diffuse reflectance circular dichroism chromatogram of the surface-loaded chiral polypyrrole nanofibers prepared in this embodiment is shown below. Figure 4 As shown. In Figure 4 The diffuse reflectance circular dichroism chromatogram shows a negative Cotton effect peak, indicating that the polypyrrole is chirally stacked, proving that the surface of the PET fiber prepared in this embodiment was successfully loaded with chiral polypyrrole.

[0057] Comparative Example 1

[0058] Comparative Example 1 provides a method for preparing a polypyrrole transistor. Compared with Example 1, the difference is that no chiral small molecule compound is added in step S2. The remaining steps are the same as in Example 1 and will not be repeated here.

[0059] The morphology of the polypyrrole-loaded fibers obtained in step S3 of this comparative example was characterized, and scanning electron microscope images with a scale bar of 1 μm were obtained, as shown below. Figure 5 As shown. By Figure 5 It can be seen that the polypyrrole loaded on the surface of the fiber monofilament is spherical, which is significantly different from the chiral polypyrrole nanowires prepared in Example 1.

[0060] To further analyze the impact of the aforementioned structural differences on transistor performance, performance tests were conducted on the chiral polypyrrole transistor prepared in Example 1 and the polypyrrole transistor prepared in Comparative Example 1. The transconductance signal of the chiral polypyrrole transistor prepared in Example 1 was measured to be 40 mS, while that of the polypyrrole transistor prepared in Comparative Example 1 was 3.1 mS, showing a significant difference of one order of magnitude. This demonstrates that the present invention, by preparing polypyrrole nanowires with a chiral structure and then assembling them into transistors, can effectively improve the transconductance signal of the transistor.

[0061] Based on the excellent performance of the chiral polypyrrole transistor provided by this invention, it can be applied to the field of antibody detection.

[0062] Among various antibodies, CRP is one of the most important biomarkers for distinguishing bacterial and viral infections, and it is of great significance to accurately detect it. Based on this, the chiral polypyrrole transistor prepared in Embodiment 1 is applied to the detection of CRP antibodies, and the sensitivity of the detection process is measured to be 18 mV / dec, and the detection limit is 5 μg mL -1 .

[0063] It should be noted that those skilled in the art should understand that the above examples are only used to illustrate that the chiral polypyrrole transistor prepared by the present application can be applied to the detection of CRP, but it is not limited thereto. The chiral polypyrrole transistor prepared by the present application can also be applied to the detection process of other antibodies based on similar detection principles.

[0064] Embodiments 2-5

[0065] Embodiments 2-5 respectively provide a preparation method of a chiral polypyrrole transistor, which differs from Embodiment 1 in that the concentration of the aqueous solution of the oxidizing agent in step S2 and the molar ratio of the chiral small molecule compound, the pyrrole monomer and the oxidizing agent are changed, and the remaining steps are consistent with Embodiment 1, which will not be repeated here. The corresponding parameters in each embodiment are shown in Table 1.

[0066] Table 1 Process parameters in Embodiments 2-5

[0067]

[0068]

[0069] It has been tested that the chiral polypyrrole transistor prepared in Embodiments 2-5 has a similar chiral structure and a higher transconductance signal as Embodiment 1, and can achieve accurate and sensitive detection of antibodies.

[0070] It should be noted that those skilled in the art should understand that in the preparation method of the chiral polypyrrole transistor provided by the present application, the reaction time in step S2 can be adjusted between 3-5 h, the boiling reflux time in step S3 can be adjusted between 5-15 min, and the type of fiber filament can be one of nylon fiber, aramid fiber, polyamide fiber or cotton fiber, the oxidizing agent can be one of ferric nitrate nonahydrate, ammonium persulfate or potassium persulfate, and the chiral small molecule compound can be obtained by amide reaction of any one of dodecanoyl chloride, tetradecanoyl chloride, hexadecanoyl chloride and octadecanoyl chloride with any one of phenylalanine, alanine, phenylglycine, valine, leucine, glutamic acid, isoleucine and serine. The specific reaction conditions can be adjusted according to the actual situation, and similar technical effects can be achieved, which all belong to the protection scope of the present application.

[0071] In summary, the present application provides a chiral polypyrrole transistor and a preparation method and application thereof. The present application prepares a coil from a fiber monofilament, then blends a chiral small molecule compound with a pyrrole monomer and water, fully stirs, then sequentially adds the coil and an aqueous solution of an oxidizing agent, after in-situ polymerization, removes the chiral small molecule compound, thereby generating a chiral polypyrrole nanowire on the surface of the fiber monofilament in-situ, and after assembly, a chiral polypyrrole transistor is obtained. Through the above method, the present application can prepare a chiral polypyrrole nanowire with a chiral structure, effectively regulates the structure of polypyrrole itself, and greatly improves the transconductance signal of the finally prepared chiral polypyrrole transistor. The preparation method provided by the present application is simple and easy to control, the chiral polypyrrole transistor prepared has excellent performance and good biocompatibility, and has a wide application prospect in the field of antibody detection.

[0072] The above examples are only used to illustrate the technical solutions of the present application and not limit the present application. Although the present application has been described in detail with reference to the preferred embodiments, it should be understood by those skilled in the art that the technical solutions of the present application can be modified or replaced by equivalents without departing from the spirit and scope of the technical solutions of the present application.

Claims

1. A method for preparing a chiral polypyrole transistor, characterized by, Comprise the following steps: S1, after washing and drying the fiber monofilament, uniformly wound into a coil for standby; S2, after the chiral small molecule compound is dissolved, pyrrole monomer and water are added under ice water bath condition, after stirring evenly, the coil obtained in step S1 is added, and after stirring evenly, an aqueous solution of oxidizing agent is added, and the coil is taken out after 3-5 h of reaction; The molar ratio of the chiral small molecule compound to the pyrrole monomer and the oxidizing agent is 1: (100-110): (100-110); The concentration of the aqueous solution of the oxidizing agent is 1-5 mol / L, and the oxidizing agent is ferric chloride hexahydrate; The chiral small molecule compound is L-14PheCOOH, which is obtained by amide reaction of tetradecanoyl chloride and phenylalanine, and its molecular formula is as follows: ； S3, after washing the coil taken out in step S2, it is placed in a mixed solution of ethanol and hydrochloric acid and boiled backflow for 5-15 min, then the coil is taken out and dried, and the fiber loaded with chiral polypyrrole nanowire is obtained; The chiral polypyrrole nanofiber presents a left-handed helical structure; S4, the fiber loaded with chiral polypyrrole nanowire obtained in step S3 is assembled with gel electrolyte to obtain a chiral polypyrrole transistor.

2. The method for fabricating a chiral polypyrrole transistor according to claim 1, characterized in that: In step S1, the fiber monofilament is one of polyester fiber, nylon fiber, aramid fiber, polyurethane fiber or cotton fiber.

3. The method for fabricating a chiral polypyrrole transistor according to claim 1, characterized in that: In step S4, the assembly process comprises the following steps: Two fibers of a predetermined length are taken from the fiber loaded with chiral polypyrrole nanowire obtained in step S3, and are placed in parallel at a predetermined interval; Then conductive silver paste is coated on both ends of the two fibers, and gel electrolyte is added at the part of the two fibers where no conductive silver paste is coated, so that the gel electrolyte covers the two fibers, and a chiral polypyrrole transistor is obtained.

Images