Preparation method of polymerization method semiconductor yarn electrode and transistor sensor

Abstract

The invention provides a preparation method of a polymerization method semiconductor yarn electrode, which comprises the following steps of: coating hydroxyl oxidized multi-walled carbon nanotubes on yarns, forming a linear network between the hydroxyl oxidized multi-walled carbon nanotubes and pyrrole by utilizing the thermal conductivity of the hydroxyl oxidized multi-walled carbon nanotubes so as to better polymerize a conductive polymer pyrrole monomer, and then polymerizing a semiconductor conductive material pyrrole, 3, 3 '-pyrrole, 3, 3'-pyrrole, 3, 3 '-pyrrole, 3, 3'-pyrrole, 3, 3 '-pyrrole and 3, and carrying out in-situ polymerization on poly 3, 4-ethylenedioxythiophene to obtain the multi-walled carbon nanotube / poly 3, 4-ethylenedioxythiophene / polypyrrole conductive composite yarn electrode. The semiconductor yarn electrode which is simple in process, mild in reaction condition, low in production cost and good in conductivity is prepared. The invention also provides a transistor sensor, which takes a semiconductor yarn as a source drain electrode and then takes a yarn treated by a perfluorosulfonic acid solution and a specific enzyme as a grid electrode, has the advantages of strong anti-interference performance, high accuracy, good sensitivity, detection limit of 1nM / L and wide detection range, can detect glucose with the concentration of 5nM / L to 1mM / L, and can be applied to the field of wearable electronic sensing.

Description

Technical Field

[0001] The present invention belongs to the field of organic electrochemical transistors, and particularly relates to a preparation method of a polymerized semiconductor yarn electrode and a transistor sensor. Background Art

[0002] In recent years, with the booming development of emerging industries such as the Internet, big data, and artificial intelligence, biosensing technology has been deeply studied, wearable technology has been widely applied and commercialized, and miniaturized wearable electronic devices have received more attention from researchers. To better integrate them into daily life, flexible electrodes and flexible sensors can work properly under high and multiple deformations due to the excellent flexibility and bendability of their substrates. Therefore, the research and development of flexible electrodes and sensors are very important for the development of wearable devices.

[0003] As a branch of electronic devices, organic transistors have been applied in fields such as sensing and gating switches due to their miniaturization. However, the biocompatibility and flexibility of the devices need to be further improved. Transistor sensors with basic semiconductor yarn electrodes are widely used in biosensing and health detection fields by virtue of the flexibility and biocompatibility of the electrode materials.

[0004] To promote the further application of transistor sensors based on semiconductor yarn electrodes in the field of wearable electronics, the selection of electrodes and semiconductor materials has received attention. Preparing semiconductor yarn electrodes by a polymerization method has good electrical conductivity. In addition, the high adsorption of semiconductor materials by the gate of the transistor sensor prepared by this method after Nafion treatment can ensure a high electron transfer rate, further improving the sensitivity of the transistor sensor.

[0005] Currently, patent CN202010369888.1 uses a solution method to prepare a transistor sensor. This method prepares a transistor sensor by adsorbing different electropositive / negative solutions. However, this method has problems such as poor conductivity and complex preparation processes.

[0006] Therefore, it is necessary to design a transistor sensor with good conductivity, low cost, mild reaction conditions, strong anti-interference ability, and high sensitivity to achieve stable detection of biomolecules. Summary of the Invention

[0007] To overcome these challenges, the present invention provides a preparation method of a polymerized semiconductor yarn electrode with relatively mild reaction conditions, low production cost, and good electrical conductivity. The present invention also provides a transistor sensor with good sensitivity and strong anti-interference ability to achieve real-time and stable detection of glucose in the body and can be applied to the field of wearable electronic sensing.

[0008] The present invention provides a preparation method of a polymerized semiconductor yarn electrode, which comprises the following steps:

[0009] S1. Immerse the pre-treated yarn in a multi-walled carbon nanotube suspension with a concentration of 9 wt%, perform ultrasonic oscillation for 30 min to load the multi-walled carbon nanotubes on the yarn, then rinse the yarn with distilled water and dry it at 90 °C for 2 h. Repeat this process three times to obtain a multi-walled carbon nanotube conductive yarn group;

[0010] S2. Prepare an emulsion solution with a concentration of 15 wt% using a surfactant and an organic solvent, and prepare a first oxidant solution with a concentration of 5 mol / L - 8 mol / L using an oxidant and deionized water;

[0011] S3. Under ice bath conditions, stir the emulsion solution for 30 min, then dropwise add the first oxidant solution. The volume ratio of the emulsion solution to the first oxidant solution is 1 - 5:100, and stir again for 4 h; Immerse the multi-walled carbon nanotube conductive yarn group and stir for 20 min; Then dropwise add 3,4-ethylenedioxythiophene accounting for 0.4% - 0.6% of the total solution volume and stir for 4 h; Conduct a chemical in-situ polymerization once to form a poly(3,4-ethylenedioxythiophene) conductive layer, take it out and wash it successively with acetonitrile, ethanol and distilled water, and dry it to obtain a multi-walled carbon nanotube / poly(3,4-ethylenedioxythiophene) conductive yarn group;

[0012] S4. Mix pyrrole monomer with water and pre-cool it at -5 °C - 5 °C for 20 min to prepare a pyrrole solution with a concentration of 0.1 mol / L - 0.3 mol / L. At the same time, mix an oxidant, a dopant and deionized water to prepare a second oxidant solution with a concentration of 0.05 mol / L - 0.25 mol / L;

[0013] S5. Under ice bath conditions, immerse the multi-walled carbon nanotube / poly(3,4-ethylenedioxythiophene) conductive yarn group in the pyrrole solution and stir for 30 min, then dropwise add the second oxidant solution and stir for 2 h to conduct a second chemical in-situ polymerization of a linear polypyrrole semiconductor layer; Take it out and soak and wash it successively with absolute ethanol, hydrochloric acid and deionized water for 20 min, and dry it at 90 °C for 2 h to obtain a multi-walled carbon nanotube / poly(3,4-ethylenedioxythiophene) / polypyrrole semiconductor yarn electrode.

[0014] Preferably, in the preparation method of the poly-method semiconductor yarn electrode,

[0015] the yarn is one of cotton, polyester or acrylic, and the diameter is 280 - 310 um;

[0016] the multi-walled carbon nanotubes are hydroxylated multi-walled carbon nanotubes.

[0017] Preferably, in the preparation method of the polymerized semiconductor yarn electrode, the pretreatment includes: cleaning and drying impurities on the yarn; soaking the yarn in acetone, absolute ethanol, and distilled water in sequence under a tension of 10 cN for ultrasonic cleaning for 30 min, and then drying in an oven at 90 °C for 2 h.

[0018] Preferably, in the preparation method of the polymerized semiconductor yarn electrode, the preparation method of the multi-walled carbon nanotube suspension includes the following steps: Dissolve hydroxy-oxidized multi-walled carbon nanotube powder in absolute ethanol, add a dispersant, stir for 10 min, start ultrasonic treatment after the hydroxy-oxidized multi-walled carbon nanotube powder is completely wetted, the ultrasonic time is 30 min, and after the ultrasonic treatment is completed, take out the suspension and let it stand to defoam. Among them, the mass ratio of the hydroxy-oxidized multi-walled carbon nanotube powder, the absolute ethanol, and the dispersant is 2:97.6:0.4.

[0019] Preferably, in the preparation method of the polymerized semiconductor yarn electrode,

[0020] The organic solvent is one of n-hexane and xylene;

[0021] The surfactant is sodium dioctyl sulfosuccinate;

[0022] The volume ratio of the surfactant to the organic solvent is 1:5.

[0023] Preferably, in the preparation method of the polymerized semiconductor yarn electrode, the concentration of the first oxidant solution is 7 mol / L, and the first oxidant is one of anhydrous ferric chloride and ferric chloride hexahydrate.

[0024] Preferably, in the preparation method of the polymerized semiconductor yarn electrode, the ice bath condition is -5 °C - 5 °C.

[0025] Preferably, in the preparation method of the polymerized semiconductor yarn electrode, in the second oxidant solution, the dopant is p-toluenesulfonic acid, the second oxidant is one of anhydrous ferric chloride and ferric chloride hexahydrate, and the mass ratio of the dopant to the second oxidant is 1:4.1.

[0026] The present invention also provides a transistor sensor fabricated using the polymerized semiconductor yarn electrode, which includes source and drain electrodes, a gate electrode, and a gel electrolyte disposed between the source and drain electrodes, wherein;

[0027] The source and drain electrodes and the gate electrode are made of multi-walled carbon nanotube / poly(3,4-ethylenedioxythiophene) / polypyrrole semiconductor yarn electrodes;

[0028] The gate is prepared by the following method: taking a multi-walled carbon nanotube / poly(3,4-ethylenedioxythiophene) / polypyrrole semiconductor yarn electrode and immersing it in a glucose oxidase solution with a concentration of 1-10 mg / mL, taking it out after treating for 12-24 h under ice bath conditions, and then placing it in a perfluorosulfonic acid solution with a mass percentage concentration of 0.5-3% under ice bath conditions for 12-24 h, and taking it out to air dry under ice bath conditions.

[0029] Preferably, in the transistor sensor,

[0030] The length of the source-drain electrode is 1.5-2 cm;

[0031] The length of the gate is 2-3 cm;

[0032] The source-drain electrode and the gate are fixed on a plastic substrate, and the distance between the source-drain electrode and the gate is 0.4 cm;

[0033] The gel electrolyte is composed of 43 wt% of water, 14 wt% of sodium polystyrene sulfonate, 30 wt% of phosphoric acid, and 13 wt% of polyvinyl alcohol;

[0034] The concentration of the glucose oxidase solution is 5 mg / mL;

[0035] The mass percentage concentration of the perfluorosulfonic acid solution is 0.5%;

[0036] The ice bath condition is below -5°C.

[0037] Compared with the prior art, the present invention has the following advantages:

[0038] Utilizing the synergistic effect of carbon nanotubes and poly(3,4-ethylenedioxythiophene) to improve the capacitance of the electrode, using plasma modification to improve the bonding strength between materials, improving the cycle stability of the electrode, through the deposition of multi-walled carbon nanotubes on the surface of the yarn group and the advantages of the emulsion solution, realizing the regulation of the PPy polymerization reaction process and morphology, forming a regular transistor structure conducive to electron transmission and migration, achieving good sensitivity and excellent anti-interference ability, and the transistor sensor can be applied to fields such as wearable electronic devices, energy storage, and sensors.

[0039] This transistor sensor can detect glucose with high sensitivity, and can work at a low gate voltage with small energy loss, which has great market promotion value for wearable devices.

[0040] Other advantages, objectives, and features of the present invention will be partially reflected by the following description, and partially will also be understood by those skilled in the art through the research and practice of the present invention. Brief Description of the Drawings

[0041] To more clearly illustrate the specific embodiments of the present invention or the technical solutions in the prior art, the following will briefly introduce the accompanying drawings required for the description of the specific embodiments or the prior art. Obviously, the accompanying drawings in the following description are some embodiments of the present invention. For those of ordinary skill in the art, without creative efforts, other drawings can also be obtained based on these drawings.

[0042] Figure 1 Flow chart of an embodiment of the preparation method of the polymerized semiconductor yarn electrode provided by the present invention;

[0043] Figure 2 Electron microscope images of coating PEDOT and PPy in an embodiment of the preparation method of the polymerized semiconductor yarn electrode provided by the present invention; the left figure is a SEM image, and the right figure is an enlarged image of PPy;

[0044] Figure 3 Comparison chart of output curves of CNT / PEDOT and CNT / PEDOT / PPy in an embodiment of the preparation method of the polymerized semiconductor yarn electrode provided by the present invention; the left figure is the output curve of the transistor sensor cotton / carbon nanotube / poly(3,4-ethylenedioxythiophene), and the right figure is the output curve of the transistor sensor cotton / carbon nanotube / poly(3,4-ethylenedioxythiophene) / polypyrrole;

[0045] Figure 4 Transfer curves and transconductance curves of CNT / PEDOT and CNT / PEDOT / PPy in an embodiment of the preparation method of the polymerized semiconductor yarn electrode provided by the present invention; the left figure is the transfer curve of the transistor sensor cotton / carbon nanotube / poly(3,4-ethylenedioxythiophene), and the right figure is the transfer curve of the transistor sensor cotton / carbon nanotube / poly(3,4-ethylenedioxythiophene) / polypyrrole;

[0046] Figure 5 Schematic structural diagram of the transistor sensor provided by the present invention;

[0047] Figure 6 Manufacturing flow chart of the transistor sensor provided by the present invention;

[0048] Figure 7 Transfer curves and transconductance curves of the transistor sensor provided by the present invention under different bending radii; the left figure is the transfer curve, and the right figure is the transconductance curve;

[0049] Figure 8 Detection diagram of glucose by the transistor sensor provided by the present invention; the left figure is the sensitivity, and the right figure is the specificity. Specific embodiments

[0050] The following further elaborates on the present invention in conjunction with the accompanying drawings so that those skilled in the art can implement it with reference to the text of the specification.

[0051] It should be understood that terms such as "having", "comprising", and "including" used herein do not preclude the presence or addition of one or more other elements or combinations thereof.

[0052] Example 1

[0053] As Figure 1 shown, the present invention provides a method for preparing a polymerized semiconductor yarn electrode, comprising the following steps:

[0054] 1) Pretreatment of cotton yarn: Clean and dry the impurities on the cotton yarn. First, soak the cotton yarn in 10 ml of acetone, absolute ethanol, and distilled water in sequence with a certain tension (10 cN), ultrasonically clean for 30 min, and then dry in an oven at 90 °C for 2 h.

[0055] 2) Preparation of multi-walled carbon nanotube suspension: Dissolve 2.00 g of hydroxy-oxidized multi-walled carbon nanotube powder in 97.60 g of absolute ethanol, add 0.4 g of dispersant, stir for 10 min until the hydroxy-oxidized multi-walled carbon nanotube powder is completely wetted, then start ultrasonic treatment for 30 min. After ultrasonic treatment is completed, take out the suspension and let it stand to defoam.

[0056] 3) Preparation of cotton / multi-walled carbon nanotube electrode: Measure 20 ml of the suspension in step 2) with a measuring cylinder, pour it into a beaker, completely immerse the cotton yarn in step 1) in the suspension, perform ultrasonic oscillation for 30 min to load the multi-walled carbon nanotubes on the cotton yarn. After ultrasonic treatment, repeatedly rinse the cotton yarn with distilled water to remove the overly loaded multi-walled carbon nanotubes on the surface. Dry in an oven at 90 °C for 2 h. Repeat the dipping-drying process three times.

[0057] 4) Preparation of cotton / MWCNT / PEDOT electrode:

[0058] First, prepare an emulsion solution, namely a 15 wt% solution of sodium bis(2-ethylhexyl) sulfosuccinate. Weigh 15 g of sodium bis(2-ethylhexyl) sulfosuccinate AOT with an analytical balance and measure 100 ml of n-hexane with a measuring cylinder.

[0059] Then, prepare a second oxidant solution, namely a 7 mol / L iron chloride solution.

[0060] Stir the solution of sodium bis(2-ethylhexyl) sulfosuccinate in an environment at 4 °C for 30 min, then dropwise add the oxidant solution and mechanically stir for 4 h. After that, completely immerse the yarn in the solution and stir for 20 min. Use a micro-syringe to measure 235 μL of 3,4-ethylenedioxythiophene (EDOT) and dropwise add it to the solution, and stir in an ice bath for 4 h. After completion, take out the cotton fiber bundle, and successively wash the unreacted solution on the cotton fiber with 10 ml of acetonitrile, ethanol, and distilled water, and obtain the cotton / MWCNT / PEDOT yarn electrode after drying.

[0061] 5) Prepare the mixed solution A: Use a pipette to measure 0.608 ml of pyrrole monomer (Py) and add it to 30 ml of deionized water, and pre-cool for 20 min.

[0062] 6) Prepare the mixed solution B: Weigh 1.826 g of ferric chloride hexahydrate and 1.292 g of p-toluenesulfonic acid, and measure 30 ml of deionized water with a measuring cylinder.

[0063] 7) Preparation of multi-walled carbon nanotube / poly(3,4-ethylenedioxythiophene) / polypyrrole semiconductor yarn electrode: Take the yarn electrode from step 4), completely immerse it in solution A, stir at 4 °C for 30 min, then dropwise add the mixed solution B, polymerize for 2 h, take it out after the reaction, and successively soak it in anhydrous ethanol, hydrochloric acid (concentration 37%) and deionized water for 20 min each to remove the overloaded PPy. Dry in an oven at 90 °C for 2 h to obtain the carbon nanotube / poly(3,4-ethylenedioxythiophene) / polypyrrole semiconductor yarn electrode.

[0064] Comparative Example 1

[0065] Comparative Example 1 provides a preparation method of a polymerized semiconductor yarn electrode. Compared with Example 1, the difference is that in step 5), the measured pyrrole monomer is 0.05 mol / L, in step 6), the ferric chloride hexahydrate is 1.826 g, and the volume fraction of the dopant is 0.00143%. The rest is roughly the same as in Example 1 and will not be elaborated here.

[0066] Comparative Example 2

[0067] Comparative Example 2 provides a preparation method of a polymerized semiconductor yarn electrode. Compared with Example 1, the difference is that in step 5), the measured pyrrole monomer is 0.1 mol / L, in step 6), the ferric chloride hexahydrate is 1.217 g, and the volume fraction of the dopant is 0.0287%. The rest is roughly the same as in Example 1 and will not be elaborated here.

[0068] Comparative Example 3

[0069] Comparative Example 3 provides a method for preparing a polymerized semiconductor yarn electrode. Compared with Example 1, the difference lies in that in step 5), the pyrrole monomer taken is 0.1 mol / L, and in step 6), ferric chloride hexahydrate is 2.435 g, and the volume fraction of the dopant is 0.0585%. The rest is substantially the same as in Example 1 and will not be elaborated here.

[0070] Comparative Example 4

[0071] Comparative Example 4 provides a method for preparing a polymerized semiconductor yarn electrode. Compared with Example 1, the difference lies in that in step 5), the pyrrole monomer taken is 0.1 mol / L, and in step 6), ferric chloride hexahydrate is 3.043 g, and the volume fraction of the dopant is 0.0717%. The rest is substantially the same as in Example 1 and will not be elaborated here.

[0072] Table 1 Process parameter settings of Example 1 and Comparative Examples 1 - 4

[0073]

[0074]

[0075] As Figure 2 shown, the magnification factors are 700 times (left) and 10,000 times (right) respectively. The highly ordered π - π stacking of multi - walled carbon nanotubes is conducive to the transport of carriers. Poly(3,4 - ethylenedioxythiophene) wraps the fibers together in a dense nano - particle structure in the form of a film, improving the connection between the fibers, further increasing the adhesion of polypyrrole, and increasing the conductive path.

[0076] As Figure 3 shown, when a positive voltage is applied to the transistor gate, under the action of V gs , the polystyrene sulfonate in the channel will undergo doping - dedoping reactions; in the right figure, the structure constructed by polypyrrole and multi - walled carbon nanotubes can provide more channels for ion transfer, making Ids change faster. In addition, at a lower voltage, the change in Ids increases linearly, conforming to Ohm's law. The ionic gel medium modulates the carriers, and I ds shows saturation.

[0077] As Figure 4 shown, when V gs gradually increases, the carriers between the source and drain are neutralized by the cations in the electrolyte, resulting in less carrier flow and a decrease in current. Therefore, V gs has a regulatory effect on the fiber - based OECT, with a transconductance value of 6 mS and a switching ratio of 3. While in the right figure, the structure constructed by linear polypyrrole and networked poly(3,4 - ethylenedioxythiophene) can provide more channels for ion transfer, making I dsIt changes faster, with a maximum transconductance value of 24.12 mS and a switching ratio of 68.82, and the results are consistent with those of Example 1.

[0078] As Figure 5 shown, the present invention also provides a transistor sensor fabricated using the polymerized semiconductor yarn electrode, which includes a source electrode, a drain electrode, a gate electrode, and a gel electrolyte disposed between the source-drain electrode and the gate electrode, wherein;

[0079] The source electrode, the drain electrode, and the gate electrode are made of the polymerized semiconductor yarn electrode, with a length of 2 - 3 cm;

[0080] The gel electrolyte is composed of 43 wt% water, 14 wt% sodium polystyrene sulfonate, 30 wt% phosphoric acid, and 13 wt% polyvinyl alcohol.

[0081] Its preparation process is as Figure 6 shown as follows:

[0082] Take two multi-walled carbon nanotube / poly(3,4-ethylenedioxythiophene) / polypyrrole semiconductor yarn electrodes with a length of 1.5 - 2 cm, fix them on a plastic substrate, apply 0.4 cm of conductive silver paste at both ends, and coat an organic solvent at the end of the silver paste to isolate it, so as to prepare the source-drain electrodes and define the channel; then take a multi-walled carbon nanotube / poly(3,4-ethylenedioxythiophene) / polypyrrole semiconductor yarn electrode with a length of 2 - 3 cm and prepare the gate electrode through surface activation treatment. Then, arrange the source-drain electrodes and the gate electrode in parallel with a spacing of 0.4 cm, and apply the gel electrolyte at the channel restriction point, that is, assemble a multi-walled carbon nanotube / poly(3,4-ethylenedioxythiophene) / polypyrrole yarn-based transistor sensor. The gel electrolyte is a mixture of polyvinyl alcohol, phosphoric acid, sodium polystyrene sulfonate, and deionized water.

[0083] Table 2 Test results of transistor sensors fabricated with semiconductor yarn electrodes in Example 1 and Comparative Examples 1 - 4

[0084]

[0085] The gel electrolyte is a mixture of the corresponding masses of polyvinyl alcohol, phosphoric acid, sodium polystyrene sulfonate, and deionized water at 60 - 90 °C.

[0086] The surface activation treatment process of the gate electrode is as follows:

[0087] Take a multi-walled carbon nanotube / poly(3,4-ethylenedioxythiophene) / polypyrrole semiconductor yarn electrode with a length of 2-3 cm and soak it in a glucose oxidase solution with a concentration of 1-10 mg / mL. Treat it for 12-24 h under ice bath conditions, take it out, and then place it in a perfluorosulfonic acid solution with a mass percentage concentration of 0.5-3% under ice bath conditions for 12-24 h. Take it out and air-dry it under ice bath conditions to prepare the gate electrode.

[0088] The concentration of the glucose oxidase solution is 5 mg / mL.

[0089] The mass percentage concentration of the perfluorosulfonic acid solution is 0.5%.

[0090] The ice bath condition is below -5 °C.

[0091] As Figure 7 shown, at different bending radii, as V gs increases, Ids decreases. As the bending angle changes, its turn-on current also changes. When the bending radius is 0 cm, the transconductance value is 22.37 mS. When the bending radius is 0.5 cm, the transconductance value is 20.78 mS. When the bending radius is 1.0 cm, the transconductance value is 20.68 mS. When the bending radius is 1.5 cm, the transconductance value is 19.2 mS. When the bending radius is 2 cm, the transconductance value is 17.5 mS. As the bending angle increases, the performance of the fiber-based OECT decreases, but still remains at a relatively high level. The results show that bending has little effect on the performance of the fiber-based OECT, which may be due to the stable structure formed by MWCNT and PPy improving the stability of the fiber-based OECT.

[0092] As Figure 8 shown, the added glucose concentration is 5 nM - 100 μM, applying V gsIt is 0.5V. Before 200s, the Ids without adding glucose is 12.86 μA. After 200s, 5 nM concentration of glucose is added drop by drop, and the current starts to respond. The Ids decreases rapidly. After that, the Ids rebounds. Then 100 nM concentration of glucose is added drop by drop, the current decreases, and then the Ids rebounds again. When other concentrations are added drop by drop, the rule is the same as above. The overall detection range can reach 5 nM - 1 mM, and the detection limit is as low as 5 nM. The specificity is reflected in: when glucose, uric acid, and NaCl are added drop by drop on the biosensor, in the first 100s, the current of the device itself is 5.3 μA. After adding 500 nM glucose, the change value of the current is 23.9 μA. After the reaction ends, the current rebounds. When 500 nM uric acid is added, the change value of the current is 7.96 μA. When 500 nM NaCl is added, the change value of the current is 8.2 μA. When 500 nM glucose is added continuously, the change value of the current is 21.70 μA. The change values of the current for adding 500 nM glucose twice are not very different. When uric acid and NaCl are added, the change values of the current are very small, indicating that it has good specificity for glucose.

[0093] The semiconductor yarn electrode prepared by the present invention has good conductivity and stability (still maintaining 50 Ω after 30 days); the prepared transistor sensor can stably detect the real-time change of glucose concentration in human sweat (detection limit 1 nM / L, detection range 1 nM / L - 1 mM / L); it has good sensitivity (transconductance 24 mS) and good flexibility (the transconductance remains 80% when the mechanical bending radius is 0 - 2 cm).

[0094] The beneficial effects of the present invention are mainly reflected in the following aspects:

[0095] 1. The semiconductor yarn electrode designed by the present invention can work normally in a bent state (bent 120°) when applied to a transistor. The networked poly(3,4-ethylenedioxythiophene) improves the conductive performance of the electrode (50 Ω). The linear polypyrrole improves the on-off ratio of the transistor sensor (68.2). The transconductance (24.12 mS) ensures good cycle stability at a low working voltage (<1V).

[0096] 2. The preparation process of the semiconductor yarn electrode designed by the present invention is simple, with low production cost and good conductivity. At the same time, this transistor sensor has the ability to detect glucose, strong anti-interference ability, high accuracy, good sensitivity, the detection limit is 1 nM / L, and the detection range is glucose with a concentration of 1 nM / L - 5 mM / L.

[0097] 3. The transistor sensor designed by the present invention uses a flexible matrix material, and the prepared transistor sensor has good flexibility. It can be made into an electronic skin sensor or woven into a fabric to make a wearable sensor, which can realize real-time monitoring of the glucose concentration in human blood.

[0098] The present invention provides a preparation method of a polymerized semiconductor yarn electrode and a transistor sensor. The semiconductor yarn electrode is prepared by coating hydroxyl oxidized multi-walled carbon nanotubes on a cotton yarn substrate after plasma cleaning. Utilizing the thermal conductivity of the multi-walled carbon nanotubes, a linear network is formed between them and pyrrole to better polymerize the conductive polymer pyrrole monomer. Then, the semiconductor conductive materials pyrrole and 3,4-ethylenedioxythiophene are in-situ polymerized onto the composite yarn treated with multi-walled carbon nanotubes to obtain a uniform and dense linear multi-walled carbon nanotube / poly(3,4-ethylenedioxythiophene) / polypyrrole conductive composite yarn electrode. Finally, a semiconductor yarn is used as the source and drain electrodes, and the yarn treated with perfluorosulfonic acid solution and specific enzyme is used as the gate electrode to form a transistor sensor. The preparation method of the present invention has a simple process, relatively mild reaction conditions, low production cost, and good conductivity of the semiconductor yarn electrode. At the same time, the prepared transistor sensor has strong anti-interference ability, high accuracy, good sensitivity, a detection limit as low as 1 nM / L, and a wide detection range. It can detect glucose with a concentration of 5 nM / L to 1 mM / L and can be applied to the field of wearable electronic sensing.

[0099] Although the embodiments of the present invention have been disclosed as above, it is not limited to the applications listed in the specification and embodiments. It can be fully applied to various fields suitable for the present invention. For those familiar with the field, additional modifications can be easily made. Therefore, without departing from the general concept defined by the claims and the equivalent scope, the present invention is not limited to the specific details and the examples shown and described herein.

Claims

1. Preparation method of a polymerized semiconductor yarn electrode, characterized in that, It includes the following steps: S1. Immerse the pre-treated yarn in a multi-walled carbon nanotube suspension with a concentration of 9 wt%, perform ultrasonic oscillation for 30 min to load the multi-walled carbon nanotubes on the yarn, then rinse the yarn with distilled water, dry it at 90 °C for 2 h, and repeat three times to prepare a multi-walled carbon nanotube conductive yarn group; S2. Prepare an emulsifying solution with a concentration of 15 wt% using a surfactant and an organic solvent, and prepare a first oxidant solution with a concentration of 5 mol / L - 8 mol / L using an oxidant and deionized water; S3. Under ice bath conditions, stir the emulsifying solution for 30 min, then dropwise add the first oxidant solution. The volume ratio of the emulsifying solution to the first oxidant solution is 1 - 5:100, and stir again for 4 h; immerse the multi-walled carbon nanotube conductive yarn group and stir for 20 min; then dropwise add 3,4-ethylenedioxythiophene accounting for 0.4% - 0.6% of the total solution volume, and stir for 4 h; perform chemical in-situ polymerization once to form a poly(3,4-ethylenedioxythiophene) conductive layer, take it out and wash it successively with acetonitrile, ethanol and distilled water, and dry it to obtain a multi-walled carbon nanotube / poly(3,4-ethylenedioxythiophene) conductive yarn group; S4. Mix pyrrole monomer with water and pre-cool it for 20 min at a temperature of -5 °C - 5 °C to prepare a pyrrole solution with a concentration of 0.1 mol / L - 0.3 mol / L. At the same time, mix an oxidant, a dopant with deionized water to prepare a second oxidant solution with a concentration of 0.05 mol / L - 0.25 mol / L; S5. Under ice bath conditions, immerse the multi-walled carbon nanotube / poly(3,4-ethylenedioxythiophene) conductive yarn group in the pyrrole solution and stir for 20 - 40 min, then dropwise add the second oxidant solution and stir for 1 - 3 h to perform secondary chemical in-situ polymerization of a linear polypyrrole semiconductor layer; take it out and soak and wash it successively with absolute ethanol, hydrochloric acid and deionized water for 10 - 30 min, and dry it at 10 - 90 °C for 1 - 3 h to obtain a multi-walled carbon nanotube / poly(3,4-ethylenedioxythiophene) / polypyrrole semiconductor yarn electrode.

2. The preparation method of the polymerized semiconductor yarn electrode according to claim 1, wherein the yarn is one of cotton, polyester or acrylic, and the diameter is 280 - 310 um; the multi-walled carbon nanotubes are hydroxylated multi-walled carbon nanotubes.

3. The preparation method of the polymerized semiconductor yarn electrode according to claim 2, characterized in that, The pretreatment includes: cleaning and drying the impurities on the yarn; soaking the yarn completely in acetone, absolute ethanol and distilled water in turn with a tension of 10 cN and performing ultrasonic cleaning for 30 min, and then drying it in an oven at 90 °C for 2 h.

4. The preparation method of the polymerized semiconductor yarn electrode according to claim 2, characterized in that, The preparation method of the multi-walled carbon nanotube suspension includes the following steps: Dissolve hydroxylated multi-walled carbon nanotube powder in absolute ethanol, add a dispersant, stir for 10 min, start ultrasonic treatment after the hydroxylated multi-walled carbon nanotube powder is completely wetted, the ultrasonic time is 30 min, and after the ultrasonic treatment is completed, take out the suspension and let it stand for defoaming. Among them, the mass ratio of the hydroxylated multi-walled carbon nanotube powder, the absolute ethanol and the dispersant is 2:97.6:0.

4.

5. The preparation method of the polymerized semiconductor yarn electrode according to claim 4, characterized in that the organic solvent is one of n-hexane and xylene; the surfactant is sodium dioctyl sulfosuccinate; the volume ratio of the surfactant to the organic solvent is 1:

5.

6. The preparation method of the polymerized semiconductor yarn electrode according to claim 5, characterized in that, The concentration of the first oxidant solution is 7 mol / L, and the first oxidant is one of anhydrous ferric chloride and ferric chloride hexahydrate.

7. The preparation method of the polymerized semiconductor yarn electrode according to claim 6, characterized in that, The ice bath condition is -5°C to 5°C.

8. The preparation method of the polymerized semiconductor yarn electrode according to claim 7, characterized in that, In the second oxidant solution, the dopant is p-toluenesulfonic acid, the second oxidant is one of anhydrous ferric chloride and ferric chloride hexahydrate, and the mass fraction ratio of the dopant to the second oxidant is 1:1.

42.

9. A transistor sensor, characterized in that, It includes a source-drain electrode, a gate electrode, and a gel electrolyte disposed between the source-drain electrode and the gate electrode, wherein; the source-drain electrode and the gate electrode adopt the multi-walled carbon nanotube / poly(3,4-ethylenedioxythiophene) / polypyrrole semiconductor yarn electrode according to any one of claims 1-8; The gate electrode is prepared by the following method: taking the multi-walled carbon nanotube / poly(3,4-ethylenedioxythiophene) / polypyrrole semiconductor yarn electrode and soaking it in a glucose oxidase solution with a concentration of 1 to 10 mg / mL, taking it out after treating it for 12 to 24 h under ice bath conditions, and then placing it in a perfluorosulfonic acid solution with a mass percentage concentration of 0.5 to 3% and treating it for 12 to 24 h under ice bath conditions again, and taking it out and air-drying it under ice bath conditions.

10. The transistor sensor according to claim 9, characterized in that the length of the source-drain electrode is 1.5 - 2 cm; the length of the gate electrode is 2 - 3 cm; the source-drain electrode and the gate electrode are fixed on a plastic substrate, and the distance between the source-drain electrode and the gate electrode is 0.4 cm; the gel electrolyte is composed of 43 wt% of water, 14 wt% of sodium poly(p-styrenesulfonate), 30 wt% of phosphoric acid, and 13 wt% of polyvinyl alcohol; the concentration of the glucose oxidase solution is 5 mg / mL; the mass percentage concentration of the perfluorosulfonic acid solution is 0.5%; the ice bath condition is below -5°C.

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