Novel thin film material for molecular diagnosis nascent biosensor, thin film transistor and preparation method and application of novel thin film material and thin film transistor

Abstract

The invention relates to the technical field of biosensors, in particular to a novel thin film material for a molecular diagnosis nascent biosensor, a thin film transistor and a preparation method and application of the novel thin film material and the thin film transistor. The thin film transistor is prepared from a novel thin film material, the thin film material covers the surface of a substrate of the transistor, and a source electrode and a drain electrode of the transistor are arranged between the substrate and a thin film in parallel. The concentration of the cancer marker is detected by monitoring the variable quantity of threshold voltage (Vth) in a transfer curve of the organic-inorganic hybrid thin film transistor, the responsivity and sensitivity to a disease marker are improved by optimizing a semiconductor material combination, efficient detection of the low-concentration cancer marker is realized, and the method has the characteristics of no label, rapidness, simplicity and convenience, and is suitable for popularization and application. The kit is suitable for early diagnosis of diseases.

Description

Technical Field

[0001] The present invention relates to the technical field of biosensors, and particularly to a novel thin film material, a thin film transistor for a new ecological biosensor for molecular diagnosis, and their preparation methods and applications. Background Art

[0002] In recent years, the rapid development of technology has brought revolutionary changes to the field of healthcare, especially in chemometrics, which has become increasingly significant in its attention to and contribution to people's lives and health. With the emphasis on early disease diagnosis and treatment, molecular diagnostic technology plays an increasingly important role in precision medicine. Among numerous detection technologies, electronic biosensors based on thin film transistors stand out due to their unique advantages. These devices do not require the use of markers, greatly reducing costs while maintaining operational simplicity and non-invasiveness of detection. They can quickly respond to minute changes in biomolecules and are easily integrated with existing electronic systems, which enables thin film transistor biosensors to exhibit great application potential in multiple fields such as vital sign monitoring, disease biomarker detection, and environmental monitoring. However, thin film transistor biosensors still face many challenges in practical applications. Long-term operation or storage may lead to the degradation of sensor performance. Environmental factors such as water molecules, oxygen, and light can all have an adverse impact on the sensor. These effects may manifest as attenuation of the output current, shift of the threshold voltage, reduction of the mobility, and extension of the response time, etc. The decline in these performances not only affects the accuracy and reliability of the sensor but also limits its lifespan and stability in practical applications.

[0003] When existing organic semiconductor materials are applied in electronic thin film transistor devices, there are problems such as uneven molecular orientation or too short molecular packing distance, which directly leads to a low charge mobility of the thin film transistor device, thereby affecting its performance and stability. When the formed thin film transistor is used as a biosensor, it faces problems of low sensitivity and large detection limit. Especially when detecting low-concentration biomarkers, it often fails to meet the requirements of clinical early diagnosis. At the same time, its stability is poor and there are certain deficiencies in the response time, which limits its effect in rapid detection and long-term applications. Summary of the Invention

[0004] Based on the above problems, the present invention provides a novel thin film material and a thin film sensor for a new ecological biosensor for molecular diagnosis. Using a conjugated polymer as the matrix and doping it with metal oxides, the advantages of the organic and inorganic parts are integrated into the composite semiconductor through a positive synergistic effect, thereby improving the device performance and sensing performance. Using it to detect lung cancer-related biomarkers can achieve low cost, easy operation and rapid determination while improving the device performance and sensing performance.

[0005] A novel thin film material for a new ecological biosensor for molecular diagnosis is prepared from an organic-inorganic hybrid material obtained by blending a conjugated polymer and a metal oxide. Among them, the conjugated polymer includes PDBT-co-TT, and the metal oxide includes indium oxide nanoparticles, zinc oxide nanoparticles, and titanium oxide nanoparticles.

[0006] Furthermore, in the blending process of the organic-inorganic hybrid material, the volume ratio of the conjugated polymer to the metal oxide in the blend is 40 - 160:1.

[0007] Furthermore, in the blending process of the organic-inorganic hybrid material, the blending temperature is 60 - 150 °C, and the blending time is ≥ 3 h.

[0008] Based on the above novel thin film material for a new ecological biosensor for molecular diagnosis, the present invention prepares a thin film transistor, and the thin film material is located in the semiconductor layer of the thin film transistor.

[0009] Furthermore, the thin film transistor has a planar structure, the thin film material contacts the bottom gate of the thin film transistor, and is located between the source and drain of the thin film transistor.

[0010] The present invention also provides a preparation process for a thin film transistor, including substrate treatment, electrode preparation, spin coating of the semiconductor layer, and annealing treatment. The substrate treatment includes modifying the surface of the SiO dielectric layer with OTS, and the OTS modification time is 3 - 6 h. 2 The OTS modification time is 3 - 6 h.

[0011] Furthermore, the electrode preparation uses a shadow mask evaporation method. Among them, the aspect ratio of the shadow mask is 8 - 20:1, and the evaporation rate is The evaporation thickness is 20 - 100 nm.

[0012] Furthermore, the spin coating speed of the semiconductor layer is 1000 - 3500 rpm, the spin coating time is 10 - 60 s, and the amount of the blend solution used is 30 - 120 μL.

[0013] Furthermore, the annealing treatment temperature is 100 - 170 °C, and the annealing time is 10 - 60 min.

[0014] The final object of the present invention is to provide the application of the above thin film transistor in a biosensor for detecting low-concentration biomarkers related to lung cancer.

[0015] Furthermore, the detection of lung cancer markers by the thin-film transistor-based biosensor includes the preparation of the antibody solution → sterilization treatment → antibody immobilization → washing and drying process. The concentration of the antibody solution is 10-100 μg / mL; the time of the sterilization treatment is 3-12 h; the incubation temperature during the antibody immobilization process is 20-30 °C, and the incubation time is 3-6 h; the solution for washing during the washing and drying process is PBS solution; wherein, the lung cancer marker is TFF3 protein.

[0016] The advantages of this invention are as follows:

[0017] 1. By introducing functionalized indium oxide nanoparticles into the organic semiconductor thin-film material to form an organic-inorganic hybrid structure, through the interaction between the two, the molecular orientation of the thin film is significantly optimized, the π-π stacking distance between molecules is reduced, the charge mobility of the thin-film material is improved, and the stability of the material is increased through the synergistic effect formed by the organic-inorganic hybridization, solving the problems of low charge mobility and unstable material performance existing in traditional organic semiconductor materials in the prior art, and providing a new way for the application of high-performance electronic thin-film transistor devices;

[0018] 2. The thin-film transistor obtained by using the organic-inorganic hybrid thin-film material as the semiconductor layer in this invention can improve the flatness, uniformity and light transmittance of the thin film in the transistor. The improvement of the light transmittance of the thin film can reduce the reflection and scattering of light in the transistor, thereby reducing the noise of the optical signal, and further improving the signal quality of the thin-film transistor. The performance can remain consistent in repeated tests. Compared with the prior art, the thin-film transistor obtained by the organic-inorganic hybrid thin-film material in this invention improves the electrical performance while enhancing the stability, has a lower cost, is easy to operate and process, and can be rapidly determined;

[0019] 3. Based on the optimized hybrid thin-film transistor, this invention is used in the biosensor for lung cancer detection, significantly improving the detection sensitivity of TFF3 protein. This is because the functionalized indium oxide nanoparticles can have a strong interaction with TFF3 protein, thereby enhancing the signal transmission efficiency. Compared with the traditional sensors in the prior art, the functionalized surface treatment in this invention can achieve accurate detection at a lower concentration, and the detection limit of TFF3 protein reaches 0.45 ng / mL, significantly lower than the detection threshold currently used clinically, enabling the sensor to have excellent performances such as rapid response, low detection limit and long-term stability. Description of the Drawings

[0020] Figure 1 It is the synthesis route diagram of PDBT-co-TT in Example 1 of this invention;

[0021] Figure 2Flow chart for the preparation of the novel organic-inorganic hybrid thin film transistor in Example 1 of the present invention;

[0022] Figure 3 Gel permeation chromatography image of PDBT-co-TT in Example 1 of Test Example 1 of the present invention;

[0023] Figure 4 In in Example 1 of Test Example 1 of the present invention 2 O 3 Environmental field emission scanning electron microscope image;

[0024] Figure 5 Electron microscope image of PDBT-co-TT and In doped with O in Example 1 of Test Example 1 of the present invention 2 O 3 ;

[0025] Figure 6 Optical microscope image of the thin film doped with PDBT-co-TT and InO in Example 1 of Test Example 1 of the present invention 2 O 3 ;

[0026] Figure 7 Thin film transmittance curve of the novel organic-inorganic hybrid thin film transistor in Example 1 of Test Example 1 of the present invention;

[0027] Figure 8 Transfer curve of the organic-inorganic hybrid thin film transistor in Test Example 2 of the present invention;

[0028] Figure 9 Output curve of the organic-inorganic hybrid thin film transistor in Test Example 2 of the present invention (applying gate voltage 0 to -60 V);

[0029] Figure 10 Carrier mobility distribution of the organic-inorganic hybrid thin film transistor in Test Example 2 of the present invention;

[0030] Figure 11 On-off ratio distribution of the organic-inorganic hybrid thin film transistor in Test Example 2 of the present invention;

[0031] Figure 12 Relative change in carrier mobility during 30 consecutive tests of the biosensor in Test Example 3 of the present invention;

[0032] Figure 13 Relative change in current on-off ratio during 30 consecutive tests of the biosensor in Test Example 3 of the present invention;

[0033] Figure 14Signal responses detected in different concentrations of TFF3 solutions (concentration range from 1 ng / mL to 1000 ng / mL) and PBS solution in Test Example 4 of the present invention;

[0034] Figure 15 For the TFF3 detection selectivity test carried out with V th as the response signal in Test Example 4 of the present invention. Detailed implementation mode

[0035] Next, the technical solutions in the embodiments of the present invention will be clearly and completely described in conjunction with the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. Based on the embodiments in the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present invention.

[0036] The instruments used in the present invention are as follows:

[0037] Atomic force microscope model: Dimension iconXR from Germany. The tapping mode is used during the atomic microscope test, and the probe selected is the Bruker VSEP-2A type tip.

[0038] Environmental field emission scanning electron microscope model: QuantaFEG 250 from the United States.

[0039] Model of the instrument used for the probe station: Keithley 4200-SCS from the United States.

[0040] Organic semiconductor thin film transistor device preparation system: FS380-S8 from Shenzhen Vector Scientific Instruments Co., Ltd. The INFICON SQC-310C film thickness gauge is used, and the film thickness precision error is within plus or minus It can display the readings of 4 film thickness probes.

[0041] Ultraviolet-visible spectrophotometer: UV-1900i from Shimadzu, Japan.

[0042] All the drugs used in the present invention are commercially available chemically pure reagents, and the specific purchase sources are shown in Table 1:

[0043] Table 1 Reagents and manufacturers used in the examples

[0044]

[0045] Example 1

[0046] Preparation of 1-1 PDBT-co-TT polymer

[0047] In this example, the PDBT-co-TT polymer was synthesized through the Stille coupling reaction, and the chemical reaction formula is as follows Figure 1 as shown below, and the specific steps are as follows:

[0048] 1-1-1. Under a nitrogen atmosphere, 50 mg of 2,5-bis(trimethylstannyl)thieno[3,2-b]thiophene, 1 mg of tris(o-tolyl)phosphine, 50 mg of 3,6-bis(5-bromothiophen-2-yl)-2,5-bis(2-octyldodecyl)pyrrolo[3,4-c]pyrrole-1,4-dione, 1 mg of tris(dibenzylideneacetone)dipalladium, and 5 mL of ultradry chlorobenzene were successively added to a Schlenk flask. Under the condition of a temperature of 60 °C, stirring was carried out for 36 hours to carry out the polymerization reaction. One hour before the end of the reaction, 0.02 - 0.5 mL of bromobenzene was added to terminate the polymerization reaction;

[0049] 1-1-2. The polymerization reaction completed in step 1-1-1 was cooled to room temperature, and the reaction mixture was poured into a conical flask containing 50 mL of methanol and 2 mL of concentrated hydrochloric acid to precipitate the polymer product;

[0050] 1-1-3. Using the Soxhlet extraction method, the polymer product precipitated in step 1-1-2 was purified successively with methanol, ethyl acetate, and chloroform to remove impurities and low-molecular-weight oligomers;

[0051] 1-1-4. After the extraction was completed, the chloroform extract obtained in step 1-1-3 was dried by rotary evaporation to remove the solvent to obtain a dry product;

[0052] 1-1-5. In order to further purify and collect the polymer, the dry product obtained in step 1-1-4 was added to methanol to precipitate the polymer again, filtered through an organic microporous membrane, and the filtered polymer was placed in a vacuum oven at 50 °C for drying to finally obtain the PDBT-co-TT polymer.

[0053] 1-2In 2 O 3 Synthesis

[0054] In this example, In 2 O 3 powder was prepared by the solution method, and the specific steps are as follows:

[0055] 1-2-1. 1 mmol of indium nitrate and 1 mmol of hexamethylenetetramine were respectively dissolved in 5 mL of deionized water to ensure uniform dissolution. The obtained solution was injected into a three-necked flask and stirred in an oil bath reactor at 60 °C for 5 hours to ensure complete reaction;

[0056] 1-2-2. After the reaction is completed, collect the generated solid precipitate by centrifugation, and wash the precipitate with ethanol and deionized water multiple times to thoroughly remove impurities that may be generated during the reaction;

[0057] 1-2-3. Dry the washed solid at 60 °C for 6 hours to obtain pure In 2 O 3 powder.

[0058] 1-3 Preparation of the PDBT-co-TT and In 2 O 3 blending solution

[0059] 1-3-1. Weigh 10 mg of the copolymer PDBT-co-TT obtained in step 1-1, transfer the weighed PDBT-co-TT to a new small glass bottle, add a 3 mm × 5 mm magnetic stir bar to the small glass bottle, and add 1 mL of chlorobenzene solution; seal the glass bottle with a sealing film, place it on a heating platform, adjust the stirring knob to the middle gear, and continuously heat at 60 °C for at least 6 h to ensure that PDBT-co-TT is completely dissolved in the chlorobenzene solvent to obtain a chlorobenzene solution of PDBT-co-TT;

[0060] 1-3-2. Weigh 10 mg of the In 2 O 3 sample, transfer the weighed In 2 O 3 to another new small glass bottle, add a 3 mm × 5 mm magnetic stir bar to the glass bottle, and add 5 mL of ethanol. Seal the glass bottle with a sealing film, place it on a heating platform, adjust the stirring knob to the middle gear, and heat at 20 °C for at least 1 hour to dissolve In 2 O 3 completely in the ethanol solvent to obtain an In 2 O 3 solution.

[0061] 1-3-3. Blend the PDBT-co-TT chlorobenzene solution prepared in step 1-1 with the In 2 O 3 ethanol solution in a ratio of 40:1. Place the blended solution on a heating platform and heat at 60 °C for at least 3 hours to ensure that PDBT-co-TT and In 2 O 3 are fully doped, and finally obtain a blending solution of PDBT-co-TT and In 2 O 3 .

[0062] Preparation of 1-4 Novel Organic-Inorganic Hybrid Thin-Film Transistors

[0063] Using the blend solution obtained in Steps 1-3 as the semiconductor layer, a novel organic-inorganic hybrid thin-film transistor is prepared. The film formed by the blend solution covers the surface of the substrate of the thin-film transistor. The source electrode and the drain electrode of the thin-film transistor are arranged in parallel between the substrate and the film formed by the organic-inorganic hybrid material, as Figure 2 shown ( Figure 2 a uses SiO 2 dielectric layer as the substrate, Figure 2 b has a modified OTS self-assembled monolayer above SiO 2 , Figure 2 c has two Au electrodes which are respectively the deposited source electrode and drain electrode, Figure 2 d has PDBT-co-TT / In 2 O 3 as the thin-film material), and the specific preparation steps are as follows:

[0064] 1-4-1. Substrate treatment:

[0065] To ensure better contact at the interface between the SiO 2 dielectric layer and the semiconductor layer and improve the electrical performance of the organic thin-film transistor device, an OTS self-assembled monolayer needs to be modified on the surface of the SiO 2 dielectric layer.

[0066] (1) Put the silicon into a polytetrafluoroethylene basket, pour ultrapure water, ethanol and isopropanol in sequence, ultrasonically clean for 2 h at a power setting of 20%, and then dry with a nitrogen gun for standby;

[0067] (2) Treat the silicon obtained in step (1) with plasma in an oxygen environment to obtain a clean silicon wafer. Keep the oxygen flow rate between 0.1 and 1.5 mbar, set the power to 20 W, and keep cleaning for 5 min. During this period, the sample chamber is filled with white light;

[0068] (3) Prepare the OTS modification solution: Use a measuring cylinder to measure 10 mL of n-heptane, pour it into a 150 mL beaker, use a pipette gun to suck 20 μL of OTS solution, and add it to the n-heptane solution. To make the solution mix evenly, place the beaker in an ultrasonic device and ultrasonically treat for 3 minutes;

[0069] (4) Immerse the silicon wafer cleaned in step (2) into the OTS modification solution prepared in step (3), and let it stand at room temperature for 3 hours for modification. This process can form a uniform OTS self-assembled monolayer on the SiO 2 surface, thereby improving the interface contact between the dielectric layer and the semiconductor layer and ensuring that the organic-inorganic hybrid thin-film transistor device has excellent electrical performance.

[0070] 1-4-2. Electrode Preparation:

[0071] On the substrate processed in Step 1-4-1, a mask plate, a source electrode, and a drain electrode are pasted. The W / L (width-to-length ratio) of the mask plate is 8:1. A gold electrode is deposited on the silicon wafer using an inorganic evaporation instrument, and the power is adjusted to keep the evaporation rate at The final evaporation thickness is 20 nm. The mask plate is removed, leaving the precisely formed source electrode and drain electrode;

[0072] 1-4-3. Spin Coating of Semiconductor Layer:

[0073] When performing spin coating operations on a silicon wafer, it is first necessary to select an appropriate sample holder size according to the size of the silicon wafer to ensure that the silicon wafer can completely cover the evacuation area, thereby ensuring the normal operation of the instrument.

[0074] Transfer 30 μL of the blend solution of PDBT-co-TT and metal oxide In 2 O 3 and evenly cover the entire surface of the silicon wafer, ensuring no bubbles. Set the spin coating speed to 1000 rpm and the spin coating time to 10 seconds. After spin coating is completed, remove the silicon wafer and store it properly.

[0075] 1-4-4. Annealing Treatment:

[0076] To remove the residual chlorobenzene solvent and make the formed polymer film smoother, the spin-coated silicon wafer needs to be annealed. Adjust the temperature of the heating stage to 100 °C, then place the spin-coated silicon wafer on the heating stage and maintain the heating time for 10 minutes. After the annealing process is completed, remove the silicon wafer and store it.

[0077] Example 2

[0078] This example provides a method for preparing a blend solution of a novel organic-inorganic hybrid thin film material. The preparation process and raw materials are the same as those in Example 1, except that the preparation parameter conditions are different, specifically as follows:

[0079] Step 1-1-1 of this embodiment is as follows: Under a nitrogen atmosphere, 500 mg of 2,5-bis(trimethylstannyl)thieno[3,2-b]thiophene, 10 mg of tris(o-tolyl)phosphine, 500 mg of 3,6-bis(5-bromothiophen-2-yl)-2,5-bis(2-octyldodecyl)pyrrolo[3,4-c]pyrrole-1,4-dione, 10 mg of tris(dibenzylideneacetone)dipalladium, and 50 mL of ultradry chlorobenzene are successively added to a Schlenk flask. Under the condition of a temperature of 180 °C, stir for 48 hours to carry out the polymerization reaction. One hour before the end of the reaction, add 0.5 mL of bromobenzene to terminate the polymerization reaction; the amount of methanol in Step 1-1-2 is 500 mL and the concentrated hydrochloric acid is 20 mL; the drying temperature of the polymer after filtration in Step 1-1-5 is 80 °C;

[0080] In Step 1-2-1 of this embodiment, 20 mmol of indium nitrate and 20 mmol of hexamethylenetetramine are respectively dissolved in 200 mL of deionized water to ensure uniform dissolution. The obtained solution is injected into a three-necked flask and stirred in an oil bath reactor at 150 °C for 5 hours to ensure complete reaction; the drying temperature in Step 1-2-3 is 150 °C;

[0081] In Step 1-3-1 of this embodiment, 100 mg of the copolymer PDBT-co-TT obtained in Example 1 is added to 20 mL of a chlorobenzene solution; the heating temperature is 150 °C for 18 h; in Step 1-3-2, 100 mg of In 2 O 3 sample is added to 20 mL of ethanol and heated at 50 °C for 3 hours; in Step 1-3-3, the blending ratio of the PDBT-co-TT chlorobenzene solution to the In 2 O 3 ethanol solution is 80:1, the heating temperature is 150 °C, and the heating time is 6 hours.

[0082] Example 3

[0083] This example is the same as Example 1, except that the preparation parameter conditions are different. In Step 1-3-3 of this example, the blending ratio of the PDBT-co-TT chlorobenzene solution to the In 2 O 3 ethanol solution is 120:1.

[0084] In step 1-4-1 of this embodiment, during the substrate treatment, silicon is cleaned for 5 h at 100% ultrasonic power, and the oxygen flow rate is maintained between 0.1 and 1.5 mbar, and the cleaning is maintained for 30 min at a power of 80 W; 60 mL of n-heptane is taken and poured into a 150 mL beaker. 100 μL of OTS solution is aspirated with a pipette and added to the n-heptane solution. To make the solution mix evenly, the beaker is placed in an ultrasonic device and ultrasonically treated for 3 minutes;

[0085] In step 1-4-2 of this embodiment, during the electrode preparation, the W / L (width-to-length ratio) of the mask plate is 20:1, and the evaporation rate is maintained at The final evaporation thickness is 100 nm;

[0086] In step 1-4-3 of this embodiment, during the spin coating of the semiconductor layer, 120 μL of the blend solution of PDBT-co-TT and metal oxide In 2 O 3 is taken and the spin coating speed is 3500 rpm;

[0087] In step 1-4-4 of this embodiment, during the annealing treatment, the annealing temperature is 170 °C and the annealing time is 60 min.

[0088] Example 4

[0089] This embodiment is the same as Example 1, except that the preparation parameter conditions are different. In step 1-3-3 of this embodiment, the blending ratio of the PDBT-co-TT chlorobenzene solution to the In 2 O 3 ethanol solution is 160:1.

[0090] Comparative Example 1

[0091] The preparation method of the thin film material and the thin film transistor in this Comparative Example 1 is the same as that in Example 1, except that in this Comparative Example, In 2 O 3 doping is not used, and the semiconductor layer of the thin film transistor uses undoped In 2 O 3 PDBT-co-TT material.

[0092] Test Example 1 Performance Test of Thin Film Material

[0093] In this test example, the products obtained in Examples 1-4 were characterized respectively. First, through PL-GPC220 gel permeation chromatography (GPC), the number average molar mass (M n = 53.2 kDa) and dispersity of the PDBT-co-TT polymer obtained in Examples 1-4 were measured respectively at 150 °C using trichlorobenzene as the solvent, The results of GPC tests showed that the purity and molecular weight distribution of the polymers obtained in Examples 1-4 met the expected requirements. Among them, the GPC test image of Example 1 is as Figure 3 shown. The results indicated that the PDBT-co-TT polymer that met the experimental requirements was successfully prepared and purified by the method of Example 1.

[0094] The morphologies of the In 2 O 3 products obtained in Examples 1-4 were characterized respectively. Among them, the electron microscope image of the In 2 O 3 powder obtained in Example 1 is as Figure 4 shown.

[0095] The PDBT-co-TT doped with different ratios in Examples 1-4 and the In 2 O 3 blend solution and Comparative Example 1 without doped In 2 O 3 were subjected to electron microscope scanning tests respectively. The obtained electron microscope images are as Figure 5 shown, showing the structural and morphological characteristics of the blend solution obtained after doping In 2 O 3 , which are significantly different from the morphology of undoped Comparative Example 1 (1:0).

[0096] The silicon wafers treated in Examples 1-4 were subjected to electrical characterization and thin film characterization respectively. The obtained results showed that the thin film materials of Examples 1-4 all exhibited good flatness and light transmittance. Among them, Figure 6 showed the optical microscope image of the organic-inorganic hybrid thin film obtained in Example 1 spin-coated on the evaporated gold electrode, indicating that the thin film had good flatness and uniformity. Figure 7 showed the light transmittance test of the thin films obtained in Example 1 and Comparative Example 1. Compared with the result of Comparative Example 1 without doped In 2 O 3 , the thin film material doped with In 2 O 3 in Example 1 significantly improved the light transmittance of the thin film. The improvement of the light transmittance of the thin film can reduce the reflection and scattering of light in the transistor, thereby reducing the noise of the optical signal. Reducing the noise can improve the signal quality and reliability of the transistor, making it more advantageous in high-frequency and low-power applications. Therefore, compared with Comparative Example 1, the material of Example 1 of the present invention helps to improve the performance of thin film transistor devices.

[0097] Test Example 2 Electrical Performance Test of Thin Film Transistors

[0098] Use a Keithley 4200-SCS semiconductor parameter analyzer to test the transfer and output characteristic curves of the thin-film transistor devices prepared in Example 1, and calculate performance parameters such as the mobility (μ) and on / off ratio (I on / I off ) of the thin-film transistor devices to characterize their electrical properties. The test process is as follows:

[0099] (1) Place the thin-film transistor device on the sample stage of the probe station. Turn on the pump switch and gas path switch of the sample stage in sequence to firmly adsorb the glass slide on the sample stage, ensuring that it will not be affected by mechanical vibration or position offset during the test;

[0100] (2) Select an objective lens with an appropriate magnification. By adjusting the focal length, make the source and drain electrodes in the thin-film transistor device clearly imaged on the display. Install probes for connecting the source, drain electrodes, and gate on the probe holder of the probe station. With the assistance of the display, precisely adjust the position of the probes to ensure good contact with the source, drain electrodes, and gate, thereby ensuring the accuracy of the measurement.

[0101] (3) After completing the connection of the equipment, open the KTTE software in the computer and start setting the measurement parameters: For the measurement of I G -V G , set V SD to -60 to -20 V, and V G is swept from 10 V to -40 V. For the measurement of I G -V SD , set V G from 0 V to -60 V, and record an output characteristic curve at every -10 V.

[0102] (4) After all the measurements are completed, carefully remove the probes to ensure no damage to the thin-film transistor devices. Through these steps, detailed electrical characteristic data of the thin-film transistor devices can be obtained, providing a reliable experimental basis for subsequent analysis and applications.

[0103] The obtained results are as Figures 8 - 11 shown, where Figure 8 is the transfer curve of the organic-inorganic hybrid thin-film transistor, showing that the charge transport characteristics of hole carriers can be modulated by V G ; Figure 9 is the output curve of the organic-inorganic hybrid thin-film transistor, indicating that the prepared thin-film transistor devices can exhibit a good transition from linear to saturation and can effectively regulate the current during operation, thus ensuring its stable working state; Figure 10 is the carrier mobility distribution of 25 organic-inorganic hybrid thin-film transistors, and the average mobility is obtained as 0.82 cm 2 V -1s -1 ; Figure 11 is the switching ratio distribution of 25 organic-inorganic hybrid thin film transistors, and the average switching ratio is 2.2×10 5 .

[0104] Test Example 3: Stability Test of Thin Film Transistors

[0105] The electrical performance stability of the novel organic-inorganic hybrid thin film transistor device is crucial for the development and application of biosensors. In this test example, the electrical characteristic curves of the same device were measured continuously 30 times to evaluate its stability.

[0106] The results are shown in Figure 12 and Figure 13 . Among them, Figure 12 shows the relative change in carrier mobility during 30 consecutive tests of the device; Figure 13 shows the relative change in current switching ratio during the same process.

[0107] The test results show that the change in the electrical performance of the device during multiple repeated tests is extremely small, indicating that the fabricated novel organic-inorganic hybrid thin film transistor device has excellent stability. The calculated relative changes in mobility and current switching ratio during 30 tests are very limited, further verifying the consistency of the electrical performance of the device during repeated tests. This result not only demonstrates the excellent performance of the device in short-term tests but also implies its reliability and stability during long-term use, which has important implications for the practical application of thin film transistor-based biosensors, indicating that the device has the potential to maintain its performance for a long time in the actual operating environment and provides strong support for the development and application of sensors.

[0108] Test Example 4: Detection of Lung Cancer Marker TFF3 Protein by Novel Organic-Inorganic Hybrid Thin Film Transistor Biosensor

[0109] The specific operation of the novel organic-inorganic hybrid thin film transistor applied in a biosensor for detecting the lung cancer marker TFF3 protein is as follows:

[0110] (1) Preparation of 30 - 100 μg / mL TFF3 antibody solution: First, take out the AFP antibody solution with a concentration of 0.5 - 2 mg / mL stored in a 1 mL centrifuge tube from the -80°C refrigerator and thaw it step by step. The specific thawing steps are as follows: First, transfer the centrifuge tube to the 4°C refrigerator. After it is completely thawed, place it at room temperature for dilution. The dilution process is as follows: Add 50 - 200 μL of 1×PBS solution to the thawed antibody solution and mix it evenly using a shaker. Then, take out 10 - 60 μL of TFF3 antibody solution from this centrifuge tube and transfer it to another new centrifuge tube. In the new centrifuge tube, add another 100 - 200 μL of 1×PBS solution and mix it evenly using a shaker until the TFF3 antibody solution is completely prepared. Finally, label the prepared TFF3 antibody solution and store it in the 4°C refrigerator for subsequent experiments.

[0111] (2) Sterilization operation: Before performing biological operations, it is necessary to thoroughly sterilize the items and the operating table used to prevent contamination and ensure the accuracy of experimental results. The operating table needs to be sterilized with an ultraviolet lamp for at least 5 to 8 hours to effectively kill surface microorganisms. The tools and utensils used in the experiment are processed through an autoclave. First, rotate the upper cover of the autoclave counterclockwise until the upper and lower handles are separated, then carefully remove the upper cover, turn on the power supply, and ensure that the water level indicator light is flashing. Take out the wire basket inside the pot and add secondary distilled water to the cylinder body. The water level should be flush with the inner tank bracket. If the water level is too high, excess water can be drained by opening the drain valve. Next, place the items to be sterilized, such as pipette tips, slide boxes, beakers, weighing bottles, etc., into the wire basket, ensuring that the items are properly placed to avoid damage or uneven sterilization. Then, close the upper cover of the autoclave and rotate the handle clockwise to ensure complete closure and ensure that the interlock indicator light is on. Set the sterilization temperature to 100°C and the time to 30 minutes, and start the heating program. When the temperature rises to 95°C, the pressure light comes on. At this time, the pressure gauge reading is negative, indicating that the autoclave is in a safe state and the upper cover cannot be opened. At this time, open the exhaust valve and perform a small amount of exhaust for about ten minutes to remove the residual air, and then close the exhaust valve. When the temperature rises to the set temperature, the sterilization countdown starts. After sterilization is completed, open the exhaust valve and wait for the pressure gauge reading to return to zero. At this time, rotate the handle counterclockwise, open the upper cover, take out the sterilized items, and then turn off the power supply and cover the upper cover to prevent secondary contamination. Through such a strict sterilization procedure, the aseptic state of the experimental environment is ensured, greatly reducing the risk of contamination during the experiment, thus guaranteeing the reliability and repeatability of biological experimental results.

[0112] (3) Immobilization of the TFF3 antibody: When performing the immobilization operation of the TFF3 antibody, first carefully place all sterilized items on the sterilized operating table to ensure that the entire experimental process is carried out in a sterile environment. Then, use scissors to cut two pieces of dust-free sponge, soak them completely with secondary distilled water, and then lay them flat in the slide box to provide support for the immobilization of the silicon wafer. Use tweezers to carefully take out the silicon wafer, and drop 1 - 5 μL of secondary distilled water on its surface to ensure that the silicon wafer can be firmly fixed on the sponge. This step prepares for the immobilization of the antibody. Next, thoroughly mix the prepared TFF3 antibody solution with a concentration of 20 - 80 μg / mL using a shaker to ensure uniform distribution of the antibody. Then, take 10 - 40 μL of the antibody solution and evenly drop it onto the copper mesh on the surface of the silicon wafer. Incubate the silicon wafer at room temperature (20 - 25 °C) for 1 hour to promote the physical adsorption of the antibody on the polymer surface. At this time, it is necessary to record the incubation time carefully to ensure the accuracy and repeatability of the experimental process. After incubation, use tweezers to slowly take out the slide from the slide box, and gently rinse the surface of the silicon wafer 2 to 6 times with 0.01×PBS solution to remove the unadsorbed antibody residues. During the rinsing process, ensure gentle movements to prevent damage to the adsorbed antibody. Then, use dust-free paper to gently absorb the excess solution along the edge of the copper mesh to avoid forming liquid droplet residues. Finally, place the silicon wafer in a room temperature (20 - 25 °C) environment to air dry for at least 2 - 30 seconds to ensure that there is no water trace on the surface and the antibody is firmly adsorbed on the polymer surface. At this time, the TFF3 antibody has been immobilized on the polymer surface through physical adsorption to form a stable sensing interface, and then electrical signal detection can be carried out. The completion of this process marks that the core functional component of the biosensor is ready, and the next detection experiment can be carried out.

[0113] After the reaction of the target analyte, precise detection of the concentration of the target analyte is achieved by monitoring the change in the threshold voltage (V th ) of the transfer curve of the organic-inorganic hybrid thin-film transistor device. This change directly reflects the interaction between the analyte and the sensor interface and has high sensitivity. The response calculation formula is: ΔV th =(V - V 0 ), where V represents the threshold voltage measured after the reaction of the target analyte, and V 0 is the reference threshold voltage before the introduction of the analyte. To ensure the accuracy of the data and the repeatability of the results, it is necessary to measure the transfer curve of the device multiple times before detecting the analyte. Usually, repeat the measurement at least five times until the obtained transfer curves completely overlap to establish a stable electrical signal baseline. Such a pretreatment step is crucial for reducing noise effects and ensuring detection sensitivity and reliability. Therefore, during the experimental process, the stability of the reference signal should be confirmed first, and then the detection operation of the target analyte can be carried out.

[0114] Result analysis:

[0115] The results are as Figure 14 and Figure 15 shown, where Figure 14 the signal responses detected in TFF3 solutions at different concentrations (ranging from 1 ng / mL to 1000 ng / mL) and PBS solution are presented. The test results indicate that the biosensor exhibits good sensing performance for TFF3 at various concentrations. In particular, its detection limit is 0.45 ng / mL, which is significantly lower than the current clinical detection threshold. This characteristic makes it have broad application prospects in early lung cancer screening and can effectively identify biomarkers at the early stage of the disease. To ensure the reliability and accuracy of the detection results, the experiments at each concentration were repeated and evaluated five times. In addition, through the systematic analysis of the signal responses at different concentrations, the optimization direction of the sensor performance can be further explored, thereby promoting its translational potential in actual clinical applications.

[0116] Figure 15 shows the selectivity test of TFF3 detection with V th as the response signal. The solutions used in the test include 1×PBS, TFF3, and human serum albumin (HSA), all at a concentration of 1 μg / mL. First, after adding the phosphate buffer solution as a blank control, a small degree of V TH shift of the organic-inorganic hybrid thin-film transistor device was observed. This result indicates that compared with the signal response caused by specific immune reactions, the ΔV TH change caused by 1×PBS can be ignored. This phenomenon further emphasizes the rationality of the experimental design and helps to confirm the interference degree of other components on the sensor signal. In addition, after adding 1 μg / mL of HSA, the V th shift amplitude of the organic-inorganic hybrid thin-film transistor device was observed to be much smaller than the ΔV th caused by TFF3. This differential result not only strengthens the high specificity of the biosensor for TFF3 but also indicates that the sensor can effectively distinguish different biomolecules. This specific recognition ability provides important support for its clinical application, enabling it to reliably detect target biomarkers in complex biological samples, thereby contributing to improving the accuracy and reliability of early diagnosis.

[0117] In summary, the present invention selects the conjugated polymer PDBT-co-TT with high mobility and stable performance and the metal oxide In 2 O 3As a semiconductor layer, a high-performance and stable organic-inorganic hybrid thin-film transistor biosensor was constructed by optimizing the preparation conditions. Meanwhile, by means of physical adsorption, TFF3 antibody was modified on the sensing surface as a bio-sensitive probe to achieve label-free, low-cost, simple and rapid detection of the clover factor 3 protein antigen, with a detection limit of 0.45 ng / mL, significantly lower than the current clinical detection value. Compared with the traditional enzyme-linked immunosorbent assay method, the preparation and analysis process of this sensor only takes 45 minutes, reflecting its high efficiency and convenience in clinical applications. In the future, this biosensor is expected to be combined with integrated circuit technology to achieve simultaneous and efficient detection of multiple tumor markers. This progress will greatly improve the accuracy of early cancer diagnosis and provide a more reliable tool for clinical detection. In addition, the optimized biosensor design and fast response characteristics may also promote its wide application in other biomarker detections and related fields, thus providing new solutions for early disease screening and personalized medicine.

[0118] For those skilled in the art, the present invention is not limited to the details of the above exemplary embodiments, and can be implemented in other specific forms without departing from the spirit or basic characteristics of the present invention; therefore, from any point of view, the embodiments should be regarded as exemplary and non-limiting. The scope of the present invention is defined by the appended claims rather than the above description. Therefore, all changes falling within the meaning and scope of the equivalent elements of the claims are intended to be included in the present invention. Any reference signs in the claims should not be regarded as limiting the claims involved.

[0119] The above are only the preferred embodiments of the present invention, and are not intended to limit the present invention. Any minor modifications, equivalent substitutions and improvements made to the above embodiments based on the technical essence of the present invention should be included in the protection scope of the technical solution of the present invention.

Claims

1. A novel thin film material for molecular diagnostic new ecological biosensor, characterized in that: The invention is prepared from an organic-inorganic hybrid material blended with a conjugated polymer and a metal oxide, wherein the conjugated polymer includes PDBT-co-TT, and the metal oxide includes indium oxide nanoparticles.

2. The novel thin film material for molecular diagnostic new ecological biosensor according to claim 1, characterized in that: In the blending process of the organic-inorganic hybrid material, the volume ratio of the conjugated polymer to the metal oxide is 40-160:

1.

3. The novel thin film material for molecular diagnostic new ecological biosensor according to claim 2, characterized in that: The conjugated polymer and metal oxide blend is a blend of PDBT-co-TT chlorobenzene solution and In2O3 ethanol solution.

4. The novel thin film material for molecular diagnostic new ecological biosensor according to claim 2, characterized in that: During the blending process of the organic-inorganic hybrid material, the blending temperature is 60-150° C., and the blending time is ≥3 hours.

5. The novel thin film material for molecular diagnostic new ecological biosensor according to claim 1, characterized in that: The conjugated polymer is synthesized by Stiller coupling reaction, the reaction temperature is 60-180° C., and the reaction time is 36-48 hours.

6. A thin film transistor, characterized in that: The novel thin film material for the new ecological biosensor for molecular diagnosis is prepared from any one of claims 1 to 5, wherein the thin film material is located in the semiconductor layer of a thin film transistor.

7. The thin film transistor according to claim 6, characterized in that: The thin film material covers the surface of the substrate of the thin film transistor, and the source electrode and the drain electrode of the thin film transistor are arranged in parallel between the substrate and the thin film formed by the organic-inorganic hybrid material.

8. A process for preparing a thin film transistor according to claim 6, comprising substrate treatment, electrode preparation, semiconductor layer spin coating and annealing treatment, characterized in that: The substrate treatment includes modifying the surface of the SiO2 dielectric layer using OTS, and the OTS modification time is 3-6 hours; the electrode preparation adopts a mask evaporation method, and the mask width-to-length ratio is 8-20:1, and the evaporation rate is The evaporation thickness is 20-100 nm; the annealing temperature is 100-170° C., and the annealing time is 10-60 min.

9. The process for preparing a thin film transistor according to claim 8, characterized in that: The speed of spin coating of the semiconductor layer is 1000-3500 rpm, the time of spin coating is 10-60 s, and the amount of the mixed liquid is 30-120 μL.

10. An application of the thin film transistor according to claim 6, characterized in that: Used in biosensors for detecting low-concentration biomarkers related to lung cancer.

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