CN115096965B - Thin film transistor type biochemical sensing microarray chip and preparation method thereof - Google Patents

Abstract

The thin film transistor type biochemical sensing micro array chip provided by the invention comprises: a substrate; the pixel array comprises a plurality of reference electrodes and a plurality of pixel units, wherein each pixel unit comprises a thin film transistor and a sensitive electrode positioned above the thin film transistor, the bottom gate electrode of the thin film transistor is electrically connected with the sensitive electrode, the surface of the sensitive electrode is provided with a decoration layer, and the reference electrodes are in one-to-one correspondence with the pixel units in a plurality of rows; a plurality of row selection signal lines respectively electrically connected with the reference electrodes; a plurality of column read signal lines; a plurality of common electrode lines; and a plurality of isolation walls positioned above the packaging layer, wherein each isolation wall surrounds an isolation area, and the isolation areas continuously expose all the sensitive electrodes and one reference electrode in one row of pixel units. The invention is beneficial to improving the chip integration level and reducing crosstalk and power consumption.

Description

Thin film transistor type biochemical sensing microarray chip and preparation method thereof

Technical field

The present invention relates to the field of sensing technology, and in particular to a thin film transistor biochemical sensing microarray chip and a preparation method thereof.

Background technique

Among various potential measurement technologies, sensors based on field-effect transistors (FETs) have received widespread attention due to their advantages such as small size, parallel sensing, short response time, and compatibility with electronic manufacturing processes. Some other types of ion-sensitive sensing devices have been derived based on field effect transistors, which provide a device platform for a variety of biochemical sensors and have achieved significant development. They are widely used in food safety, environmental monitoring, medical diagnosis, chemistry, etc. analysis, soil testing, etc.

In electrochemical sensing chip technology, many domestic and foreign research institutions and enterprises have implemented integrated detection of various microarray chips through CMOS (Complementary Metal-Oxide-Semiconductor, complementary metal oxide semiconductor) integrated circuit process design. However, the use of silicon-based CMOS technology to prepare sensor chips not only has process deficiencies such as high cost and poor customizability, but is also difficult to be compatible with the integration of multiple sensing front-ends, and the packaging process is also relatively complex. Thin film transistors have received a lot of application research due to their low manufacturing cost, short design cycle, preparation by solution method, and direct integration with a variety of sensing materials. With the development of the Internet of Things, the number of sensors has greatly increased, and low-power multi-sensor chips will become the future development trend of electrochemical sensing. Most current work involves integrating limited sensors. Integrated arrays provide a feasible technical solution for realizing multi-sensing applications. Therefore, the system requires multiple gating modules to obtain signals from each unit pixel. Current solutions include at least two transistors, one of which is used for switching gating, and the other is used to integrate with the sensor to process the sensing signal. However, the two-transistor solution will not only increase the size of the chip, but is also prone to problems such as leakage, crosstalk, and high power consumption, thus affecting the performance of the chip.

Therefore, how to reduce the size of the sensor chip, improve the performance of the sensor chip, and expand the application field of the sensor chip is an urgent technical problem that needs to be solved.

Contents of the invention

The invention provides a thin film transistor type biochemical sensing microarray chip and a preparation method thereof, which are used to solve the problem of large size of existing sensing chips, improve the performance of the sensing chip, and expand the application field of the sensing chip.

In order to solve the above problems, the present invention provides a thin film transistor biochemical sensing microarray chip, including:

substrate;

A pixel array, located on the substrate, includes a plurality of reference electrodes and a plurality of pixel units arranged in an array. The pixel unit includes a thin film transistor and a sensitive electrode located above the thin film transistor. The thin film The transistor includes a bottom gate electrode, a bottom gate insulating layer covering the bottom gate electrode, a source electrode and a drain electrode located on the surface of the bottom gate insulating layer, a semiconductor layer covering the source electrode and the drain electrode, and a semiconductor layer covering the source electrode and the drain electrode. The encapsulation layer of the semiconductor layer, the bottom gate electrode is electrically connected to the sensitive electrode, the surface of the sensitive electrode has a modification layer, and a plurality of the reference electrodes correspond to multiple rows of the pixel units in one-to-one correspondence;

A plurality of row selection signal lines are located on the substrate, and the plurality of row selection signal lines are electrically connected to a plurality of reference electrodes respectively;

A plurality of column read signal lines are located on the substrate, and the drain electrodes in the pixel units in each column are connected to the same column read signal line;

A plurality of common electrode lines located on the substrate, each common electrode line connecting all the source electrodes in the pixel units in each column;

A plurality of isolation walls, each of which is continuously distributed over all the encapsulation layers of a row of pixel units, and each of the isolation walls surrounds an isolation area, and the isolation area is continuously exposed to a row of the pixel units. All the sensitive electrodes and one reference electrode corresponding to one row of pixel units.

Optionally, the reference electrode includes an Ag/AgCl electrode and a porous polymer membrane containing saturated chlorine salt.

Optionally, the chloride salt is sodium chloride or potassium chloride, and the porous polymer membrane is made of polyvinyl chloride or polyvinyl butyral or polyvinyl butyral and polyethylene oxide-polymer. Blend material of propylene oxide-polyoxyethylene triblock copolymer.

Optionally, the bottom gate electrode, the source electrode, the drain electrode, the row selection signal line, the column read signal line, and the common electrode line are all made of conductive polymer, carbon-based Conductors, metals, metal oxides, metal nanowires, metal or metal oxide nanoparticles.

Optionally, the material of the semiconductor layer is an inorganic material, an organic small molecule semiconductor material, a polymer semiconductor material, or a small molecule semiconductor material-polymer insulating material hybrid system.

Optionally, the semiconductor layer covers part of the source electrode, part of the drain electrode, and the bottom gate insulating layer between the source electrode and the drain electrode, and the encapsulation layer covers the A semiconductor layer, a portion of the source electrode, a portion of the drain electrode and the bottom gate insulating layer; the thin film transistor further includes:

A conductive interconnection layer penetrates the encapsulation layer and part of the bottom gate insulating layer. One end of the conductive interconnection layer is electrically connected to the bottom gate electrode, and the other end is electrically connected to the sensitive electrode.

Optionally, a plurality of the pixel units are arranged in an array along the first direction and the second direction, and the plurality of pixel units arranged at intervals along the first direction serve as a row of pixel units, and the first direction and The second directions are all directions parallel to the top surface of the substrate, and the first direction intersects the second direction;

Each of the reference electrodes is located outside a row of pixel units along the first direction, and a plurality of the reference electrodes are arranged at intervals along the second direction.

Optionally, the material of the modification layer is cyclohexanone, polyvinyl chloride, potassium tetrakis(3,5-bis(trifluoromethyl)phenyl)borate, tetrakis[3,5-bis(trifluoromethyl) ) phenyl] sodium borate, bis(2-ethylhexyl) sebacate, ionophore, biochemically sensitive materials, or biologically sensitive materials.

Optionally, the material of the isolation wall is a hydrophobic material.

In order to solve the above problems, the present invention also provides a method for preparing a thin film transistor type biochemical sensing microarray chip, which includes the following steps:

Provide a substrate;

A pixel array, a plurality of row selection signal lines, a plurality of column read signal lines and a plurality of common electrode lines are formed on the top surface of the substrate. The pixel array includes a plurality of reference electrodes and are arranged in a column array. A plurality of pixel units are arranged, and the pixel unit includes a thin film transistor and a sensitive electrode located above the thin film transistor. The thin film transistor includes a bottom gate electrode, a bottom gate insulating layer covering the bottom gate electrode, and a sensitive electrode located above the bottom gate electrode. The source electrode and the drain electrode on the surface of the gate insulating layer, the semiconductor layer covering the source electrode and the drain electrode, the encapsulation layer covering the semiconductor layer, the bottom gate electrode is electrically connected to the sensitive electrode, and the sensitive electrode The surface has a modification layer, a plurality of the reference electrodes correspond to a plurality of rows of the pixel units, a plurality of the row selection signal lines are electrically connected to a plurality of the reference electrodes respectively, and the pixel units in each column are The drain electrodes are all connected to the same column read signal line, and each common electrode line is connected to all the source electrodes in the pixel units in each column;

A plurality of isolation walls are formed above the pixel array, each of the isolation walls is continuously distributed over all the packaging layers of the pixel unit in a row, each of the isolation walls surrounds an isolation area, and the isolation area is continuously All the sensitive electrodes in one row of the pixel units and one of the reference electrodes corresponding to one row of the pixel units are exposed.

The invention provides a thin film transistor biochemical sensing microarray chip and a preparation method thereof. Only one thin film transistor is provided in each pixel unit of the pixel array, and the switching function and sensing function of the pixel unit are integrated into the same thin film transistor. , thereby reducing the size of the entire thin film transistor-type biochemical sensing microarray chip by reducing the size of each pixel unit. Moreover, since only one thin film transistor is provided, it can reduce leakage, crosstalk and other problems of the thin film transistor type biochemical sensing microarray chip, and help reduce the power consumption of the thin film transistor type biochemical sensing microarray chip, thereby improving sensing. The performance of the chip expands the application fields of sensing chips.

The thin film transistor type biochemical sensing microarray chip provided by the invention can be combined with an RFID (radio frequency identification) system, can be coupled through a mobile phone antenna, and can be rectified and stabilized to achieve passive power supply. At the same time, it can be powered by a DAC (digital-to-analog conversion). The module provides a bias voltage, and the ADC (analog-to-digital conversion) reads the current and voltage after conversion. The pixel unit structure including only one thin film transistor is conducive to multi-sensing and multi-site detection, and the overall system can achieve low voltage and low power consumption. Work. In addition, the pixel array formed by thin film transistors is compatible with substrates (such as flexible substrates) and can achieve conformal and close fit with flexible surfaces such as skin, thereby ensuring stable and reliable signal detection, significantly reducing noise, and is expected to be used in in wearable sweat detection and other fields. The diverse material selection (such as semiconductor materials, packaging layer materials, bottom gate insulating layer materials, etc.) and flexible process optimization enable it to cope with diverse sensing needs and have a shorter design-to-product production cycle.

Description of the drawings

Figure 1 is a schematic structural diagram of a thin film transistor type biochemical sensing microarray chip in a specific embodiment of the present invention;

Figure 2 is a schematic structural diagram of a thin film transistor in a specific embodiment of the present invention;

Figure 3 is a schematic structural diagram of a thin film transistor biochemical sensing microarray chip combined with RFID in a specific embodiment of the present invention;

Figure 4 is a flow chart of a method for preparing a thin film transistor-type biochemical sensing microarray chip in a specific embodiment of the present invention.

Detailed ways

The specific embodiments of the thin film transistor type biochemical sensing microarray chip and its preparation method provided by the present invention will be described in detail below with reference to the accompanying drawings.

This specific embodiment provides a thin film transistor type biochemical sensing microarray chip. Figure 1 is a schematic structural diagram of the thin film transistor type biochemical sensing microarray chip in the specific implementation of the present invention. Figure 2 is a specific implementation of the present invention. Schematic diagram of the structure of a medium thin film transistor. As shown in Figures 1 and 2, the thin film transistor biochemical sensing microarray chip includes:

substrate 20;

The pixel array is located on the substrate 20 and includes a plurality of reference electrodes 10 and a plurality of pixel units 19 arranged in a column array. The pixel units 19 include thin film transistors and sensitive electrodes located above the thin film transistors. 28. The thin film transistor includes a bottom gate electrode 21, a bottom gate insulating layer 22 covering the bottom gate electrode 21, a source electrode 23 and a drain electrode 24 located on the surface of the bottom gate insulating layer 22, covering the source electrode 23 and the semiconductor layer 25 of the drain electrode 24 and the encapsulation layer 26 covering the semiconductor layer 25. The bottom gate electrode 21 is electrically connected to the sensitive electrode 28. The surface of the sensitive electrode 28 has a modification layer 29, and a plurality of The reference electrode 10 corresponds to multiple rows of the pixel units 19 in a one-to-one correspondence;

A plurality of row selection signal lines 14 are located on the substrate 20, and the plurality of row selection signal lines 14 are electrically connected to a plurality of reference electrodes 10 respectively;

A plurality of column read signal lines 11 are located on the substrate 20, and the drain electrodes 24 in each column of the pixel units 19 are connected to the same column read signal line 11;

A plurality of common electrode lines 12 are located on the substrate 20, and each common electrode line 12 connects all the source electrodes 23 in each column of the pixel units 19;

A plurality of isolation walls 13, each of which is continuously distributed over all the encapsulation layers of a row of pixel units, each of the isolation walls 13 surrounds an isolation area 131, and the isolation area 131 continuously exposes all the packaging layers of a row of pixel units. All the sensitive electrodes 28 in the pixel units 19 and one reference electrode 10 corresponding to one row of the pixel units 19.

Specifically, a plurality of the pixel units 19 are arranged in a two-dimensional array along the first direction D1 and the second direction D2 on the top surface of the substrate 20 to form the pixel array. The first direction D1 may be a row direction of the pixel array, and the second direction D2 may be a column direction of the pixel array. Each pixel unit 19 includes only one thin film transistor. As shown in FIG. 2 , the thin film transistor includes the bottom gate electrode 21 on the top surface of the substrate 20 , the bottom gate insulating layer 22 covering the bottom gate electrode 21 , and the bottom gate electrode 21 on the top surface of the substrate 20 . The source electrode 23 and the drain electrode 24 on the surface of the insulator 22, the semiconductor layer 25 covering part of the source electrode 23, and the gap area between the source electrode 23 and the drain electrode 24, covering all The semiconductor layer 25 , a portion of the source electrode 23 , a portion of the drain electrode 24 , and a portion of the encapsulation layer 26 of the bottom gate insulating layer 22 . The bottom gate electrode 21 located in the same pixel unit 19 is electrically connected to the sensitive electrode 28 . Multiple reference electrodes 10 correspond to multiple rows of pixel units 19 in a one-to-one correspondence, that is, each row of pixel units 19 shares the same reference electrode 10 . The first direction D1 and the second direction D2 are both directions parallel to the top surface of the substrate 20 , and the first direction D1 and the second direction D2 intersect. The intersection described in this specific embodiment may be a vertical intersection or an oblique intersection.

The thin film transistor type biochemical sensing microarray chip also includes a channel selection circuit 17 and a plurality of row selection signal lines 14. One end of each row selection signal line 14 is electrically connected to the channel selection circuit 17 and the other end. One end is connected to one of the reference electrodes 10 . Each isolation wall 13 is continuously distributed over all the encapsulation layers 26 of the pixel units 19 in a row, and each isolation wall 13 surrounds and continuously exposes all the sensitive electrodes 28 in the pixel units 19 in a row. , and one isolation area 131 of one reference electrode 10 corresponding to one row of pixel units 19, that is, the isolation wall 13 is in a frame shape to surround one row of pixels in the isolation area 131. All of the sensitive electrodes 28 of the unit 19 and one of the reference electrodes 10 . When testing the solution to be tested, the pixel units 19 in two adjacent rows are isolated from each other by the isolation wall 13 , and the solution to be tested is placed in the isolation area 131 in one of the isolation walls 13 , the reference electrode 10 and the sensitive electrode 28 exposed through the isolation area 131 form a conductive path through the solution to be tested, so as to realize the detection of the solution to be tested.

The thin film transistor type biochemical sensing microarray chip also includes a reading circuit 15 and a plurality of column reading signal lines 11 electrically connected to the reading circuit 15. The pixel units 19 in each column The drain electrodes 24 are all connected to the same column read signal line 11 . The thin film transistor type biochemical sensing microarray chip also includes a power supply circuit 16 and a plurality of common electrode lines 12 connected to the power supply circuit 16. Each of the common electrode lines 12 is connected to the pixels in each column. All said source electrodes 23 in unit 19.

The thin film transistor type biochemical sensing microarray chip may also include a control circuit 18. The control circuit 18 may be electrically connected to the reading circuit 15 and the channel selection circuit 17, so that the control circuit 18 can The reading circuit 15 and the channel selection circuit 17 transmit control signals to control the working state of each pixel unit 19 in the pixel array. The working state includes an open state and a closed state.

Optionally, the reference electrode 10 includes an Ag/AgCl electrode and a porous polymer membrane containing saturated chlorine salt.

Optionally, the chloride salt is sodium chloride or potassium chloride, and the porous polymer membrane is made of polyvinyl chloride (poly(vinyl chloride), PVC) or polyvinyl butyral (polyvinyl butyral, PVB). ) or a blend material of polyvinyl butyral and polyoxyethylene-polyoxypropylene-polyoxyethylene triblock copolymer (polyvinyl butyral, PVB).

Optionally, the bottom gate electrode 21, the source electrode 23, the drain electrode 24, the row selection signal line 14, the column read signal line 11, and the common electrode line 12 are all made of Conductive polymers, carbon-based conductors, metals, metal oxides, metal nanowires, metal or metal oxide nanoparticles.

Optionally, the material of the bottom gate insulating layer 22 includes but is not limited to insulating materials (such as oxide materials or nitride materials), polymer dielectric materials, and the like.

Optionally, the material of the semiconductor layer 25 is an inorganic material, an organic small molecule semiconductor material, a polymer semiconductor material, or a small molecule semiconductor material-polymer insulated hybrid system material.

Specifically, the material of the semiconductor layer 25 may include inorganic materials but is not limited to group III-V semiconductor materials, or one or both of organic small molecules and polymers, or the semiconductor layer of the thin film transistor. The materials include blends of small organic molecules or polymers and insulating polymers, or blends of small organic molecules and high molecular polymers. Wherein, the organic small molecule may be, but is not limited to, 6,13-bis(triisopropylsilylethynyl)pentacene (TIPS-pentacene), triethyl Bis(triethyl-silyle-thynyl)anthradithiophene (TES-ADT) or 2,7-diphenyl[1]benzothiophene[3,2-b][1]benzo Thiophene (2,7-dioctyl[1]benzothieno[3,2-b][1]benzothiophene, C8BTBT); the polymer can be, but is not limited to, polystyrene (polystyrene, PS), poly(triarylamine) ) (poly(triarylamine), PTAA) or poly(methylmethacrylate), PMMA).

Optionally, the semiconductor layer 25 covers part of the source electrode 23, part of the drain electrode 24, and the bottom gate insulating layer 22 between the source electrode 23 and the drain electrode 24, so The encapsulation layer 26 covers the semiconductor layer 25, part of the source electrode 23, part of the drain electrode 24 and the bottom gate insulating layer 22; the thin film transistor also includes:

Conductive interconnection layer 27 penetrates the encapsulation layer 26 and part of the bottom gate insulating layer 22. One end of the conductive interconnection layer 27 is electrically connected to the bottom gate electrode 21, and the other end is electrically connected to the sensitive electrode 28. . Wherein, the material of the conductive interconnection layer 27 is conductive polymer, carbon-based conductive material, metal, metal oxide, metal nanowire, metal or metal oxide nanoparticles.

Wherein, the conductive interconnection layer 27 may be formed by using laser vias, mechanical perforations, inkjet printing, etc. to form through-holes penetrating the encapsulation layer 26 and part of the bottom gate insulating layer 22, and then to the through-holes. The holes are filled with conductive material.

Optionally, a plurality of the pixel units 19 are arranged in an array along the first direction D1 and the second direction D2, and the plurality of pixel units 19 arranged at intervals along the first direction D1 serve as a row of pixel units. , the first direction D1 and the second direction D2 are both directions parallel to the top surface of the substrate 20, and the first direction D1 intersects the second direction D2;

Each reference electrode 10 is located outside a row of pixel units 19 along the first direction D1, and a plurality of the reference electrodes 10 are arranged at intervals along the second direction D2.

Specifically, each reference electrode 10 is arranged outside its corresponding row of pixel units 19 along the first direction D1, and a plurality of the reference electrodes 10 is arranged along the second direction D2. They are arranged in parallel and spaced apart to improve the space utilization on the top surface of the substrate 20 and to help simplify the circuit structure inside the thin film transistor type biochemical sensing microarray chip.

Optionally, the material of the modification layer 29 is cyclohexanone, polyvinyl chloride, potassium tetrakis(3,5-bis(trifluoromethyl)phenyl)borate, tetrakis[3,5-bis(trifluoromethyl) [ethyl]phenyl] sodium borate, bis(2-ethylhexyl) sebacate, ionophore, biochemically sensitive materials, or biologically sensitive materials.

Specifically, the surface of the sensitive electrode 28 can be modified by modifying a biological probe or an ion-selective membrane to form the modification layer 29, thereby generating specificity for the target detection substance. The materials of the modification layer 29 on the surface of the sensitive electrode 28 include but are not limited to cyclohexanone (C6H10O), polyvinyl chloride (PVC), and potassium tetrakis(3,5-di(trifluoromethyl)phenyl)borate. (KTFPB), sodium tetrakis[3,5-bis(trifluoromethyl)phenyl]borate (Na-TFPB), bis(2-ethylhexyl)sebacate (DOS), potassium ionophore (valine (mycin, etc.), sodium ionophores, ammonium ionophores and other ionophores, polyaniline (PANI), polypyrrole (PPy), graphene, carbon nanotubes and other biochemical sensitive materials, nucleic acid aptamers, antibodies, antigens and other biologically sensitive materials Material.

Optionally, the material of the isolation wall 13 is a hydrophobic material. The hydrophobic material may be, but is not limited to, silicone glue, PDMS (polydimethylsiloxane), etc.

The material of the encapsulation layer 26 may be, but is not limited to, metal oxide, high-performance polymer, etc. In one example, the material of the encapsulation layer 26 is CYTOP (amorphous fluorine-containing resin).

Figure 3 is a schematic structural diagram of a thin film transistor type biochemical sensing microarray chip combined with RFID in a specific embodiment of the present invention. The thin film transistor type biochemical sensing microarray chip provided in this specific embodiment can be combined with an RFID system. As shown in FIG. 3 , after the thin film transistor type biochemical sensing microarray chip is combined with the radio frequency identification structure 32 , all the pixel units 19 in each row of the thin film transistor type biochemical sensing microarray chip are The sensitive electrode 28 is electrically connected to one of the reference electrodes 10 through contact with the solution to be measured located in the isolation area 131 . When the thin film transistor biochemical sensing microarray chip works in conjunction with the radio frequency identification structure 32, the mobile terminal 30 is coupled with the antenna 31 in the radio frequency identification structure 32, and performs rectification and voltage stabilization to achieve passive power supply. The power circuit 16 provides a power supply voltage to the source electrode 23 in the thin film transistor through the common electrode line 12, and the reference electrode 10 provides a gate voltage for the row of pixel units through the channel selection circuit 17, At this time, the strobe signal is loaded on the thin film transistor through the solution to be measured, and the reading circuit 15 can read the sensing signal at this time. The channel selection circuit 17 , the reading circuit 15 and the power supply circuit 16 can be controlled by the radio frequency identification structure 32 . At the same time, since the solution to be tested for turning on the pixel units in each row is isolated from each other by the isolation wall 13, the pixel units in other non-working rows can be controlled to be in a closed state. The structure of the pixel unit including only a single thin film transistor is beneficial to multi-sensing multi-site detection and multi-modal integration. The mobile terminal 30 may be but is not limited to a mobile phone.

The microarray chip for biochemical sensing provided in this embodiment can reduce the operating voltage of the thin film transistor type sensing microarray chip by using the semiconductor layer with low bandgap state density; in addition, the microarray chip with only a low bandgap state density is used. The pixel unit with a single thin film transistor structure integrates the switching function and the sensing function in the same thin film transistor, reducing the leakage path and intra-pixel crosstalk, thereby achieving the purpose of manufacturing low-voltage and low-power sensing chips.

Not only that, this specific embodiment also provides a method for preparing a thin film transistor type biochemical sensing microarray chip. Figure 4 is a flow chart of a method for preparing a thin film transistor biochemical sensing microarray chip in a specific embodiment of the present invention. The structure of the thin film transistor type biochemical sensing microarray chip prepared in this specific embodiment can be seen in Figures 1-3. As shown in Figures 1 to 4, the preparation method of the thin film transistor type biochemical sensing microarray chip includes the following steps:

Step S41, provide substrate 20;

Step S42: Form a pixel array, a plurality of row selection signal lines 14, a plurality of column read signal lines 11 and a plurality of common electrode lines 12 on the top surface of the substrate 20. The pixel array includes a plurality of reference electrode 10, and a plurality of pixel units 19 arranged in an array. The pixel unit 19 includes a thin film transistor and a sensitive electrode 28 located above the thin film transistor. The thin film transistor includes a bottom gate electrode 21, covering the bottom gate electrode 21. The bottom gate insulating layer 22 of the gate electrode 21, the source electrode 23 and the drain electrode 24 located on the surface of the bottom gate insulating layer 22, the semiconductor layer 25 covering the source electrode 23 and the drain electrode 24, and the semiconductor layer 25 covering the source electrode 23 and the drain electrode 24. 25 of the encapsulation layer 26, the bottom gate electrode 21 is electrically connected to the sensitive electrode 28, the surface of the sensitive electrode 28 has a modification layer 29, a plurality of the reference electrodes 10 and a plurality of rows of the pixel units 19 correspond one to one , a plurality of row selection signal lines 14 are electrically connected to a plurality of reference electrodes 10 respectively, and the drain electrodes 24 in each column of the pixel units 19 are connected to the same column read signal line 11, Each common electrode line 12 connects all the source electrodes 23 in the pixel units 19 in each column;

Step S43: Form a plurality of isolation walls 13 above the pixel array. Each isolation wall 13 is continuously distributed over all the encapsulation layers 26 of the pixel units 19 in a row. Each isolation wall 13 is surrounded by An isolation area 131 continuously exposes all the sensitive electrodes 28 in a row of the pixel units 19 and one of the reference electrodes 10 corresponding to a row of the pixel units 19 .

The thin film transistor type biochemical sensing microarray chip and its preparation method provided by this specific embodiment only provide one thin film transistor in each pixel unit of the pixel array, and the switching function and sensing function of the pixel unit are integrated in the same thin film. In transistors, the size of the entire thin film transistor-type biochemical sensing microarray chip can be reduced by reducing the size of each pixel unit. Moreover, since only one thin film transistor is provided, it can reduce leakage, crosstalk and other problems of the thin film transistor type biochemical sensing microarray chip, and help reduce the power consumption of the thin film transistor type biochemical sensing microarray chip, thereby improving sensing. The performance of the chip expands the application fields of sensing chips.

The above are only preferred embodiments of the present invention. It should be noted that those of ordinary skill in the art can also make several improvements and modifications without departing from the principles of the present invention. These improvements and modifications should also be regarded as It is the protection scope of the present invention.

Claims (9)

1. A thin film transistor-type biochemical sensing microarray chip, comprising:

a substrate;

the pixel array is positioned on the substrate and comprises a plurality of reference electrodes and a plurality of pixel units which are arranged in an array, wherein each pixel unit comprises a thin film transistor and a plurality of sensitive electrodes which are positioned above the thin film transistor, each thin film transistor comprises a bottom gate electrode, a bottom gate insulating layer which covers the bottom gate electrode, a source electrode and a drain electrode which are positioned on the surface of the bottom gate insulating layer, a semiconductor layer which covers the source electrode and the drain electrode, and a packaging layer which covers the semiconductor layer, the bottom gate electrode is electrically connected with the sensitive electrodes, the surface of each sensitive electrode is provided with a modification layer, the reference electrodes are in one-to-one correspondence with a plurality of rows of pixel units, and each pixel unit only comprises one thin film transistor;

a plurality of row selection signal lines positioned on the substrate, wherein the row selection signal lines are respectively and electrically connected with the reference electrodes;

a plurality of column read signal lines on the substrate, wherein the drain electrode in each column of the pixel units is connected with the same column read signal line;

a plurality of common electrode lines on the substrate, each common electrode line connecting all the source electrodes in each column of the pixel units;

the isolation walls are in a surrounding frame shape, each isolation wall is continuously distributed above all packaging layers of one row of pixel units, each isolation wall surrounds an isolation area, each isolation area is continuously exposed to all sensitive electrodes in one row of pixel units and one reference electrode corresponding to one row of pixel units, two adjacent rows of pixel units are mutually isolated through the isolation walls, the isolation areas in the isolation walls are used for containing a solution to be detected, and the reference electrode exposed through the isolation areas and the sensitive electrode form a conductive path through the solution to be detected so as to realize detection of the solution to be detected;

the pixel units are arranged in an array along a first direction and a second direction, the pixel units are arranged at intervals along the first direction and serve as one row of pixel units, the first direction and the second direction are all directions parallel to the top surface of the substrate, and the first direction and the second direction are intersected;

each reference electrode is located outside one row of the pixel units along the first direction, and a plurality of reference electrodes are arranged at intervals along the second direction.

2. The thin film transistor type biochemical sensing microarray chip according to claim 1, wherein the reference electrode comprises an Ag/AgCl electrode and a porous polymer film containing saturated chloride salt.

3. The thin film transistor type biochemical sensing microarray chip according to claim 2, wherein the chloride salt is sodium chloride or potassium chloride, and the porous polymer film is polyvinyl chloride or polyvinyl butyral or a blend material of polyvinyl butyral and polyoxyethylene-polyoxypropylene-polyoxyethylene triblock copolymer.

4. The thin film transistor type biochemical sensing microarray chip according to claim 1, wherein the materials of the bottom gate electrode, the source electrode, the drain electrode, the row selection signal line, the column reading signal line, and the common electrode line are conductive polymers, carbon-based conductors, metal oxides, metal nanowires, metals, or metal oxide nanoparticles.

5. The thin film transistor type biochemical sensing microarray chip according to claim 1, wherein the material of the semiconductor layer is an inorganic material, an organic small molecule semiconductor material, a polymer semiconductor material, or a small molecule semiconductor material-polymer insulation material mixed system.

6. The thin film transistor type biochemical sensing microarray chip according to claim 1, wherein the semiconductor layer covers a part of the source electrode, a part of the drain electrode, and the bottom gate insulating layer between the source electrode and the drain electrode, and the encapsulation layer covers the semiconductor layer, a part of the source electrode, a part of the drain electrode, and the bottom gate insulating layer; the thin film transistor further includes:

and the conductive interconnection layer penetrates through the packaging layer and part of the bottom gate insulating layer, one end of the conductive interconnection layer is electrically connected with the bottom gate electrode, and the other end of the conductive interconnection layer is electrically connected with the sensitive electrode.

7. The thin film transistor type biochemical sensing microarray chip according to claim 1, wherein the material of the modification layer is cyclohexanone, polyvinylchloride, potassium tetrakis (3, 5-bis (trifluoromethyl) phenyl) borate, sodium tetrakis [3, 5-bis (trifluoromethyl) phenyl ] borate, bis (2-ethylhexyl) sebacate, ionophore, biochemical sensitive material, or biosensing material.

8. The thin film transistor type biochemical sensing microarray chip according to claim 1, wherein the material of the partition wall is a hydrophobic material.

9. The method for manufacturing a thin film transistor type biochemical sensing microarray chip according to claim 1, comprising the steps of:

providing a substrate;

forming a pixel array, a plurality of row selection signal lines, a plurality of column reading signal lines and a plurality of common electrode lines on the top surface of the substrate, wherein the pixel array comprises a plurality of reference electrodes and a plurality of pixel units distributed in a column array, each pixel unit comprises a thin film transistor and a sensitive electrode positioned above the thin film transistor, the thin film transistor comprises a bottom gate electrode, a bottom gate insulating layer covering the bottom gate electrode, a source electrode and a drain electrode positioned on the surface of the bottom gate insulating layer, a semiconductor layer covering the source electrode and the drain electrode, a packaging layer covering the semiconductor layer, the bottom gate electrode is electrically connected with the sensitive electrode, the surface of the sensitive electrode is provided with a modification layer, the reference electrodes are in one-to-one correspondence with a plurality of rows of pixel units, each pixel unit only comprises one thin film transistor, the row selection signal lines are respectively and electrically connected with the reference electrodes, the drain electrode in each column of pixel unit is connected with the same row reading signal line, and the common electrode in each column of pixel unit is connected with all the pixel units;

forming a plurality of isolation walls above the pixel array, wherein the isolation walls are in a surrounding frame shape, each isolation wall is continuously distributed above all packaging layers of one row of pixel units, each isolation wall surrounds an isolation area, each isolation area continuously exposes all sensitive electrodes in one row of pixel units and one reference electrode corresponding to one row of pixel units, two adjacent rows of pixel units are mutually isolated through the isolation walls, the isolation areas in the isolation walls are used for containing a solution to be detected, and the reference electrodes exposed through the isolation areas and the sensitive electrodes form a conductive path through the solution to be detected so as to realize detection of the solution to be detected.