Extended gate mosfet biosensor, detection station and detection method

Abstract

This invention relates to the fields of medical testing, biosensing, and semiconductor technology, specifically to an extended-gate MOSFET biosensor, a detection workstation, and a detection method. The sensor includes an extended-gate electrode module, a FET transducer module, and an amplification circuit board. The extended-gate electrode module is detachably connected to the FET transducer module. The extended-gate electrode module includes an electrode plate and a reference electrode, with the reference electrode disposed on the electrode plate and a detection probe fixed on the electrode plate. The FET transducer module includes a MOSFET detection socket and a MOSFET. The electrode plate is inserted into the MOSFET detection socket, and the gate of the MOSFET is connected to the extended-gate electrode module through the MOSFET detection socket. The amplification circuit board is electrically connected to the MOSFET detection socket. The extended-gate MOSFET biosensor of this invention has the advantages of low cost, high efficiency, simple packaging, insensitivity to temperature and light, and excellent long-term stability.

Description

Technical Field

[0001] This invention relates to the fields of medical testing, biosensing, and semiconductor technology, specifically to an extended-gate MOSFET biosensor, a detection workstation, and a detection method.

[0002] Extended-gate MOSFET biosensors and detection methods Background Technology

[0003] A biosensor is a device that converts biological signals into visual signals. As a tiny detection tool, it plays an important role in fields such as biomedicine, food testing, and environmental monitoring. Based on the type of signal transduction element, biosensors can be divided into electrochemical biosensors, optical biosensors, and field-effect transistor (FET) biosensors. Among these, FET biosensors are the most widely used and fastest-growing biosensors due to their high selectivity, high sensitivity, real-time response, and label-free detection.

[0004] There are two main types of FETs: junction field-effect transistors (JFETs) and metal-oxide-semiconductor field-effect transistors (MOSFETs). Due to their low power consumption, low noise, and fast switching speed, MOSFETs have become an important device in the current scientific research field.

[0005] Since 1970, the first FET-based sensor originated from the ion-sensitive field-effect transistor (ISFET) introduced by Bergweld. ISFETs have been developed in a wide range of applications, including pH sensing, early disease detection, and drug screening. Typical FET-based devices share the same basic architecture as metal-oxide-semiconductor field-effect transistors (MOSFETs) with embedded source, drain, and gate metallized contact terminals. However, ISFET transducers and the later-introduced BioFETs removed the metal gate and replaced it with a structure that includes an ion-sensitive or biological acceptor layer, an analyte solution, and an immersed reference electrode.

[0006] However, in traditional ISFETs, the ion-sensitive membrane is in direct contact with the solution to be tested. When the sensing area is exposed to the electrolyte for a long time, corrosive ions will damage the surface of the sensing area, seriously affecting the lifespan of the device. Summary of the Invention

[0007] To overcome the shortcomings of existing technologies, this invention provides a MOSFET biosensor based on an extended gate, a detection workstation, and a detection method to address the problem that in traditional ISFETs, the ion-sensitive membrane is in direct contact with the test solution, and when the sensing area is exposed to the electrolyte for a long time, corrosive ions can damage the surface of the sensing area, severely affecting the lifespan of the device.

[0008] One aspect of the present invention provides a MOSFET biosensor and detection method based on an extended gate, comprising an extended gate electrode module, a FET transducer module, and an amplification circuit board, wherein the extended gate electrode module is detachably connected to the FET transducer module;

[0009] The extended gate electrode module includes an electrode sheet and a reference electrode. The reference electrode is disposed on the electrode sheet, and a detection probe is fixed on the electrode sheet for contacting the solution to be tested and transferring the potential change to the FET transducer module.

[0010] The FET transducer module includes a MOSFET detection plate and a MOSFET. The electrode plate is inserted into the MOSFET detection plate, and the gate of the MOSFET is connected to the extended gate electrode module through the MOSFET detection plate, for converting the potential change into a change in current signal.

[0011] The amplifier circuit board is electrically connected to the MOSFET detection plug-in, and is used to amplify the current signal of the MOSFET and output it as detection data.

[0012] In one embodiment of the present invention, the MOSFET detection plug-in board includes a PCB board, an electrode holder, and a terminal block; the electrode holder is disposed at one end of the PCB board, and the electrode plate is inserted and connected to the electrode holder; the MOSFET is electrically connected to the PCB board.

[0013] In one embodiment of the present invention, the reference electrode is electrically connected to the power supply terminal of the amplifier circuit board via the terminal block and the first cable, for supplying power to the extended gate electrode module;

[0014] The voltage of the power supply terminal is from a battery or an external power source, and the power supply terminal has a transformer for stable DC power supply.

[0015] In one embodiment of the present invention, the MOSFET includes a main component and a source, a drain, and a gate disposed on the main component; the gate and the source are disposed on one side of the main component, and the drain is disposed on the other side of the main component;

[0016] The main component is configured to switch from a cutoff state to a conduction state when the gate voltage reaches a threshold voltage.

[0017] In one embodiment of the present invention, in the off state, when there is no voltage between the gate and the source, the MOSFET is in the off state and does not conduct electricity; in this state, the oxide between the gate and the source acts as an insulating layer, preventing the flow of current; when the gate voltage is 0, there is no conductive channel between the source and the drain, so no current flows.

[0018] In the on state, when a positive voltage is applied to the gate, an electric field is formed, and the direction of the electric field affects the movement of charge carriers. In an N-channel enhancement-mode MOSFET, the positive voltage causes electrons in the gate region to flow to the channel region, forming a conductive channel. When the voltage between the source and the gate is high enough, the MOSFET will turn on, allowing current to flow from the source to the drain.

[0019] In one embodiment of the present invention, the main component is an insulating gate oxide, which is SiO2, Si3N4, Al2O3, HFO2 or Ta2O5.

[0020] In one embodiment of the present invention, the source and the drain are electrically connected to the amplifier circuit board via the terminal block and the second cable, respectively.

[0021] In one embodiment of the present invention, the electrode sheet includes a working electrode, an auxiliary electrode, and a reference electrode, wherein the working electrode, the auxiliary electrode, and the reference electrode are respectively connected to the terminal block, and the MOSFET is electrically connected to the working electrode through the terminal block;

[0022] The working electrode and the auxiliary electrode are made of gold, platinum or silver, and the reference electrode is silver chloride.

[0023] In one embodiment of the present invention, the MOSFET is disposed on the amplification circuit board, and the MOSFET and the amplification circuit board are integrally formed to form an integrated detector;

[0024] Alternatively, the MOSFET is soldered onto the MOSFET detection plate.

[0025] One embodiment of the present invention also discloses a detection workstation, including a housing and an extended gate-based MOSFET biosensor as described in any of the above embodiments. The extended gate-based MOSFET biosensor is packaged inside the housing. The housing is provided with a plug-in opening corresponding to the extended gate electrode module and at least one data interface. The plug-in opening is used to enable the plugging and unplugging of the extended gate electrode module and the FET transducer module. The data interface is used to enable the amplification circuit board to establish a data connection with the data processing terminal.

[0026] The container is also equipped with a display component, which is electrically connected to the amplification circuit board for visually displaying the detection data.

[0027] One embodiment of the present invention also discloses a detection method for a MOSFET biosensor based on an extended gate, comprising:

[0028] S10. Select a suitable method for fixing the electrode sheet and probe according to the properties of the analyte;

[0029] S20. 50-100 μL of the test solution is dropped onto the electrode plate on which the probe is fixed, and the potential change of the electrode plate is transferred to the FET transducer module.

[0030] S30. The potential change is converted into a current change detection signal by the FET transducer module, and the detection signal is amplified by the amplifier circuit board.

[0031] S40. Record the amplified detection signal and display the current change through a visualization device. Analyze the detection signal to output the detection result.

[0032] The extended-gate MOSFET biosensor, detection workstation, and detection method provided by this invention can achieve the following technical effects:

[0033] 1. Separating the FET transducer module and the extended gate electrode module can effectively extend the lifespan of the MOSFET biosensor. Specifically, the extended gate electrode module contacts the solution to be tested and transfers the potential change to the MOSFET gate, while the FET transducer module converts the potential change into a current signal. In this invention, the gate sensing region is formed by the spatially separated FET transducer module and extended gate electrode module. Sensors using this structure have advantages such as low cost, high efficiency, simple packaging, insensitivity to temperature and light, and excellent long-term stability.

[0034] 2. The FET transducer module used is recyclable, while the extended gate electrode module, due to its detachable connection, can be used as a disposable component. This significantly reduces the operating and maintenance costs of the MOSFET biosensor, making measurements more economical. Positioning the extended gate electrode module away from the gate surface of the FET transducer module can eliminate interference signals caused by chemical reactions between the test solution and the semiconductor channel material, or by the effects of light intensity, temperature, and humidity.

[0035] 3. The separate extended gate electrode module also provides more possibilities for the functional structure of the sensing element in terms of conductive film selection, functionalization process, electrode geometry, and final easy integration into the sensing array, which can meet the detection needs of a variety of situations and make the detection more flexible.

[0036] 4. The testing workstation is highly portable. By setting up a display component on the housing or amplification circuit board, the test data can be displayed for users to make qualitative judgments. Further connection to a data processing terminal such as a computer or mobile phone can obtain more detailed data. The testing workstation can display directly on the amplification circuit board or be connected to a computer or mobile phone, thus realizing the miniaturization of the testing workstation. Attached Figure Description

[0037] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on the structures shown in these drawings without creative effort.

[0038] Figure 1 A schematic diagram showing the structure of the MOSFET biosensor of the present invention;

[0039] Figure 2 A schematic diagram showing the structure of the present invention, in which the extended gate electrode module and the FET transducer module are separated;

[0040] Figure 3 A three-dimensional structural schematic diagram of the MOSFET of the present invention;

[0041] Figure 4 A schematic diagram showing the circuit structure of the MOSFET of the present invention;

[0042] Figure 5 A schematic diagram showing the structure of the MOSFET of the present invention;

[0043] Figure 6 A schematic diagram illustrating the working principle of a device using antigen-antibody binding as an example;

[0044] Figure 7 A table showing the correspondence between some English abbreviations, their full English names, and their full Chinese names in the instruction manual;

[0045] Figure 8 This is a schematic diagram showing the structure of the testing workstation of the present invention;

[0046] Figure 9 This is a schematic flowchart illustrating the detection method of the present invention.

[0047] The annotations in the attached figures are explained as follows:

[0048] 1-Extended gate electrode module; 11-Electrode sheet; RE-Reference electrode; WE-Working electrode; CE-Auxiliary electrode; 2-FET transducer module; 3-Amplifier circuit board; 4-MOSFET detection plug board; 41-PCB board; 42-Electrode socket; 43-Terminal; 44-First cable; 45-Second cable; 5-MOSFET; G-Gate; S-Source; D-Drain. Detailed Implementation

[0049] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of the present invention.

[0050] Please refer to Figures 1-5 One embodiment of the present invention provides a MOSFET biosensor based on an extended gate, including an extended gate electrode module 1, a FET transducer module 2 and an amplification circuit board 3, wherein the extended gate electrode module 1 and the FET transducer module 2 are detachably connected.

[0051] The extended gate electrode module 1 includes an electrode sheet 11 and a reference electrode RE. The reference electrode RE is disposed on the electrode sheet 11, and a detection probe is fixed on the electrode sheet 11 for contacting the solution to be tested and transferring the potential change to the FET transducer module 2.

[0052] The FET transducer module 2 includes a MOSFET detection plug-in plate 4 and a MOSFET 5. The electrode plate 11 is plugged into the MOSFET detection plug-in plate 4. The gate G of the MOSFET 5 is connected to the extended gate electrode module 1 through the MOSFET detection plug-in plate 4, which is used to convert the potential change into a change in current signal.

[0053] The amplifier circuit board 3 is electrically connected to the MOSFET detection plug 4 and is used to amplify the current signal of the MOSFET 5 and output it as detection data.

[0054] Understandably, the principle of this invention is as follows: The sensing gate G and the FET transducer module 2 are spatially separated by a detachably connected extended gate electrode module 1. The gate G is extended externally, while the FET transducer module 2 and the amplifier circuit are relatively fixed by welding. The detection electrode (i.e., the working electrode, a bio-modified gold electrode) and the FET transducer module 2 are plugged into the gate electrode for easy replacement. The reference electrode RE (power supply electrode) in the extended gate electrode module 1 is directly connected to the power supply of the amplifier circuit board 3. The sensing gate G electrode and the gate G terminal of the FET transducer module 2 are connected via a detection plug-in plate. The FET transducer module 2 is fixed on the MOSFET detection plug-in plate 4. By modifying and fixing the bio-receptor onto the plugged extended gate electrode module 1, when the liquid to be tested contains the target analyte, the probe modified on the surface of the working electrode will bind to the target analyte, thereby causing a change in the carrier density inside the channel, resulting in a change in the drain (D) / source (S) current. Finally, the signal is collected by the detection system.

[0055] This embodiment can achieve the following technical effects:

[0056] 1. Separating the FET transducer module 2 and the extended gate electrode module 1 can effectively extend the lifespan of the MOSFET biosensor. Specifically, the extended gate electrode module 1 is used to contact the solution to be tested and transfer the potential change to the gate G of the MOSFET 5, while the FET transducer module 2 converts the potential change into a change in current signal. In this invention, the gate sensing region is formed by the spatially separated FET transducer module and extended gate electrode module. Sensors using this structure have advantages such as low cost, high efficiency, simple packaging, insensitivity to temperature and light, and excellent long-term stability.

[0057] 2. The FET transducer module 2 used is recyclable, while the extended gate electrode module 1, due to its detachable connection, can be used as a disposable component, thus significantly reducing the operation and maintenance costs of the MOSFET biosensor and making measurements more economical. Positioning the extended gate electrode module 1 away from the gate G surface of the FET transducer module 2 can eliminate interference signals caused by chemical reactions between the test solution and the semiconductor channel material or by the effects of light intensity, temperature, and humidity.

[0058] 3. The separate extended gate electrode module 1 also provides more possibilities for the functional structure of the sensing element in terms of conductive film selection, functionalization process, electrode geometry, and final easy integration into the sensing array, which can meet the detection needs of various situations and make the detection more flexible.

[0059] Please refer to Figure 2In one embodiment of the present invention, the MOSFET detection plug-in board 4 includes a PCB board 41, an electrode holder 42 and a terminal block 43; the electrode holder 42 is disposed at one end of the PCB board 41, and the electrode plate 11 is inserted and connected to the electrode holder 42; the MOSFET 5 is electrically connected to the PCB board 41.

[0060] Understandably, in this embodiment, the combination of PCB board 41 and electrode holder 42 provides a compact and reliable connection method. This design makes the circuit connection between the electrode plate 11 and the MOSFET detection plug 4 more stable and reduces the risk of poor connection.

[0061] Meanwhile, since the electrode plate 11 can be inserted and connected to the electrode holder 42, this design facilitates integration and maintenance. When it is necessary to replace a new or different electrode plate 11, the electrode plate 11 can be easily disassembled and reinstalled through the electrode holder 42, which improves the convenience of maintenance.

[0062] Furthermore, the electrical connection between MOSFET5 and PCB board 41 ensures the stability and reliability of signal transmission. The direct electrical connection reduces the risk of poor contact and signal loss, making the MOSFET5 more accurate in detecting voltage and current changes on electrode plate 11. It also helps to achieve high integration and low power consumption design.

[0063] Please refer to Figure 2 In one embodiment of the present invention, the reference electrode RE is electrically connected to the power supply terminal of the amplifier circuit board 3 through the terminal 43 and the first cable 44, for supplying power to the extended gate electrode module 1;

[0064] The power supply terminal is a battery or an external power source, and the power supply terminal has a transformer for stable DC power supply. In one application scenario, the voltage of the power supply terminal can be selected as 2-5V.

[0065] Understandably, connecting the reference electrode RE to the power supply terminal of the amplifier circuit board 3 via the terminal block 43 and the first cable 44 ensures that the extended gate electrode module 1 receives a stable power supply, which helps maintain signal integrity, reduces noise and interference caused by power fluctuations, and thus improves the detection accuracy of the sensor. This is crucial for maintaining the stable operation of the sensor and improving measurement accuracy.

[0066] Understandably, the PCB board 41 has a pre-embedded circuit for connecting the terminal block 43 and the electrode holder 42. The design of connecting the terminal block 43 on the PCB board 41 and the first cable 44 makes the power connection of the extended gate electrode module 1 simple and direct, which facilitates the integration of the sensor into a more complex system, while simplifying circuit design and wiring.

[0067] Furthermore, the power supply voltage range is set to 2-5V. This design allows the sensor to adapt to various power supply environments, increasing its application flexibility. This design allows the sensor to operate within a wider voltage range, improving its versatility. It can prevent excessively high voltages from damaging the sensor or the circuits connected to it, ensuring system safety. In addition, the lower supply voltage helps reduce the power consumption of the entire system.

[0068] Please refer to Figure 3 In one embodiment of the present invention, the MOSFET 5 includes a main component and a source S, a drain D and a gate G disposed on the main component; the gate G and the source S are disposed on one side of the main component, and the drain D is disposed on the other side of the main component;

[0069] The main component is configured to switch from a cutoff state to a conduction state when the gate G voltage reaches a threshold voltage.

[0070] Understandably, from an electrochemical perspective, a MOSFET-based biosensor is a three-electrode system, consisting of a source (S), a drain (D), and a gate (G). The source (S) and drain (D) connect the semiconductor channel, while the gate (G) modulates the channel's conductivity. The nanomaterial connecting the source (S) and drain (D) in the semiconductor channel serves as the sensing element. Typically, biological receptors are modified and immobilized on the surface of the semiconductor channel to identify target analytes through their high specificity and strong binding in a buffered environment. The target-receptor interaction alters the surface potential of the semiconductor channel and modulates its conductivity, ultimately collecting the signal through a detection system.

[0071] The MOSFET5 used in this invention is an N-channel enhancement-mode MOSFET, with the structure as follows: Figure 1 As shown, the N-channel enhancement-mode MOSFET operates based on the principle of controlling current through an electric field in the semiconductor. It has three main electrodes: source (S), drain (D), and gate (G). The main component in the MOSFET isolates the gate (G) from the semiconductor material. When the gate voltage (V)... GS When the current reaches a certain value, a conductive channel will be formed between the source (S) and drain (D), thus allowing current to flow.

[0072] Understandably, the threshold voltage refers to the gate-source voltage (G-S) required for a MOSFET to transition from the off state to the on state. For an N-channel enhancement-mode MOSFET, when the gate voltage (G) reaches the threshold voltage (V... T When the MOSFET is turned on, a conductive channel is formed between the source (S) and drain (D). The magnitude of the turn-on voltage depends on the specific design and material properties of the MOSFET.

[0073] For example, affecting the threshold voltage (V) T The main factors include:

[0074] In N-type MOSFETs, the channel region is P-type doped. If the doping concentration increases, it means that more gate voltage (G) is needed to attract electrons to form a conductive channel, and therefore the threshold voltage will increase accordingly.

[0075] Gate oxide thickness is another factor affecting the threshold voltage of a MOSFET. The thicker the gate oxide, the weaker the ability of the channel current to be controlled by the gate voltage, and therefore the higher the threshold voltage. By using high-quality gate oxide materials and processes, the thickness can be reduced and leakage current can be decreased while maintaining a stable threshold voltage.

[0076] The insulating layer material and its properties: Different semiconductor materials (such as silicon, gallium arsenide, etc.) have different band structures and electron mobilities. These properties directly affect the magnitude of the threshold voltage. The charge Qss in silicon dioxide (gate oxide layer) as the dielectric and the nature of the charge will affect the threshold voltage. This charge is usually generated by a variety of reasons, some of which are positively charged and some are negatively charged. The net charge will affect the threshold voltage.

[0077] Environmental factors, such as the decrease in bandgap of semiconductor materials, increase in carrier concentration, and change in mobility as temperature rises, all contribute to the threshold voltage. At the same time, they also increase the number of ionized impurities and the concentration of impurities, thus leading to a decrease in threshold voltage.

[0078] Structural design, including channel length and trench width, reduces the channel surface area when the channel length is reduced, thus affecting current flow and control. Therefore, the shorter the channel, the lower the threshold voltage.

[0079] Please refer to Figure 6 , Figure 6 This is a schematic diagram of the working principle of a device based on antigen-antibody binding. In one embodiment of the present invention, in the off state, when there is no voltage between the gate G and the source S, the MOSFET is in the off state and does not conduct electricity. In this state, the oxide between the gate G and the source S acts as an insulating layer, preventing the flow of current. When the voltage of the gate G is 0, there is no conductive channel between the source S and the drain D, so no current flows.

[0080] In the on state, when a positive voltage is applied to the gate G, an electric field is formed, and the direction of the electric field affects the movement of charge carriers. In an N-channel enhancement-mode MOSFET, the positive voltage causes electrons in the gate G region to flow to the channel region, forming a conductive channel. When the voltage between the source S and the gate G is high enough, the MOSFET will turn on, allowing current to flow from the source S to the drain D.

[0081] In one embodiment of the present invention, the main component is an insulating gate oxide, wherein the insulating gate oxide is SiO2, Si3N4, Al2O3, HFO2 or Ta2O5.

[0082] Understandably, among the various materials that can be selected for insulating gate oxides, SiO2 (silicon dioxide) is a traditional gate dielectric material. SiO2 has good thermal and electrical stability, excellent interface quality with silicon, superior electrical isolation performance, and low research and development and production costs due to its mature process.

[0083] Si3N4 (silicon nitride) has a high dielectric constant, low gate leakage and high breakdown field voltage, which helps to reduce the gate dielectric thickness, thereby reducing gate leakage and making the detection more accurate.

[0084] Al2O3 (alumina) has a large band gap, relatively high dielectric constant, and high breakdown electric field, making it a preferred material for the gate G dielectric.

[0085] HFO2 (hafnium oxide) is a high dielectric constant material with significant advantages in insulation properties. It can reduce the interaction between the gate dielectric and charge carriers, enhance the insulation performance of the gate G, improve the switching characteristics of the transistor, and also has a high dielectric constant and good contact with the substrate.

[0086] Ta2O5 (tantalum oxide) has a large dielectric constant, making it compatible with traditional semiconductor fabrication processes. Compared to traditional SiO2 thin films, it helps improve the electrical performance of thin-film transistors.

[0087] In one embodiment of the present invention, the source S and the drain D are electrically connected to the amplifier circuit board 3 via the terminal 43 and the second cable 45, respectively.

[0088] In this embodiment, the terminal 43 connecting the source S and the drain D is also connected to the working electrode of the electrode plate 11. Understandably, using the terminal 43 and the cable provides electrical isolation, reducing parasitic inductance and capacitance that may be introduced by direct soldering, which is crucial for maintaining signal integrity and reducing noise. Simultaneously, using the terminal 43 and the second cable 45 allows for more flexible wiring between the PCB board 41 and the amplification circuit board 3. Designers can adjust the length and position of the second cable 45 as needed to adapt to different installation environments and space constraints. Furthermore, since the source S and the drain D are respectively connected to the amplification circuit board 3, the current change signals detected by the source S and the drain D can be amplified by the amplification circuit board 3, which helps in recording the detection signals.

[0089] In one embodiment of the present invention, the electrode sheet 11 has dimensions of 6x36x0.25mm;

[0090] The electrode plate 11 includes a working electrode, an auxiliary electrode, and a reference electrode RE. The working electrode, the auxiliary electrode, and the reference electrode RE are respectively connected to the terminal 43. The MOSFET 5 is electrically connected to the working electrode through the terminal 43.

[0091] The working electrode and the auxiliary electrode are made of gold, platinum or silver, and the reference electrode RE is silver chloride.

[0092] Understandably, platinum electrodes are very commonly used in three-electrode systems due to their high stability and low polarization characteristics. Platinum electrodes are usually used as auxiliary electrodes (counter electrodes) because they have low resistivity and their area should be larger than that of the working electrode to reduce polarization effects and improve the sensitivity and accuracy of the measurement.

[0093] Gold electrodes possess excellent electrical conductivity, which is crucial for efficient electron transfer in electrochemical processes. Using gold electrodes as working electrodes leverages this property to ensure minimal resistance and accurate measurements. Furthermore, gold exhibits good chemical stability in most environments, resisting corrosion and guaranteeing long-term use. Additionally, gold's good plasticity and ductility allow it to be easily processed into various shapes and sizes, and its surface can be modified to exhibit different chemical properties and electrochemical performance under varying conditions. Therefore, using gold electrodes as working electrodes not only offers these advantages but also allows for rapid detection of the initial electrochemical reaction due to its extremely fast reaction rate.

[0094] Silver electrodes are primarily used in applications where reactivity is not a concern, such as silver / silver chloride reference electrodes (REs).

[0095] In one embodiment of the present invention, the MOSFET5 is disposed on the amplification circuit board 3, and the MOSFET5 and the amplification circuit board 3 are integrally formed to form an integrated detector;

[0096] Alternatively, the MOSFET 5 can be soldered onto the MOSFET detection plug-in 4.

[0097] In one application scenario of this embodiment, the MOSFET5 and the amplifier circuit board 3 are integrally formed, which can improve the integration and reduce external connections, thereby reducing space occupation and complexity. Furthermore, since the external connection points are reduced, the integrally formed detector can improve the reliability and durability of the entire sensing device. The integral design simplifies the production and assembly process because there is no need to install the MOSFET5 and connect the amplifier circuit board 3 separately, thereby reducing manufacturing costs.

[0098] In this application scenario, the MOSFET5 is soldered onto the MOSFET detection socket 4, providing greater flexibility and allowing the same MOSFET5 to be used in different applications, requiring only the detection socket to be replaced. If the MOSFET5 or the detection socket malfunctions, the connection method in this application scenario allows for quick replacement or upgrade of the MOSFET5. Furthermore, different MOSFET detection sockets 4 can be customized for different detection needs, while the MOSFET5 can remain unchanged, thus reducing the types of inventory and spare parts required.

[0099] Please refer to Figure 8 , Figure 8 This is a schematic diagram of the architecture of a detection workstation, including a housing and a MOSFET biosensor based on an extended gate as described in any of the above embodiments. The MOSFET biosensor based on an extended gate is packaged inside the housing. The housing is provided with a plug-in opening corresponding to the extended gate electrode module and at least one data interface. The plug-in opening is used to enable the plugging and unplugging of the extended gate electrode module and the FET transducer module. The data interface is used to enable the amplification circuit board to establish a data connection with the data processing terminal.

[0100] The container is also equipped with a display component, which is electrically connected to the amplification circuit board for visually displaying the detection data.

[0101] Understandably, the testing workstation is highly portable. By setting up a display component on the container or amplification circuit board, the testing data can be displayed for users to make qualitative judgments. Furthermore, by connecting to a data processing terminal such as a computer or mobile phone, more detailed data can be obtained. The testing workstation can display directly on the amplification circuit board or be connected to a computer or mobile phone, thus realizing the miniaturization of the testing workstation.

[0102] Please refer to Figure 9 One embodiment of the present invention also discloses a detection method for a MOSFET biosensor based on an extended gate, comprising:

[0103] S10. Select a suitable method for fixing the electrode sheet and probe according to the properties of the analyte;

[0104] S20. 50-100 μL of the test solution is dropped onto the electrode plate on which the probe is fixed, and the potential change of the electrode plate is transferred to the FET transducer module.

[0105] S30. The potential change is converted into a current change detection signal by the FET transducer module, and the detection signal is amplified by the amplifier circuit board.

[0106] S40. Record the amplified detection signal and display the current change through a visualization device. Analyze the detection signal to output the detection result.

[0107] Understandably, the principle of the method in this embodiment is as follows:

[0108] In step S10, commonly used electrode sheet 11 materials include gold, silver, platinum, and carbon-based materials such as graphite and conductive polymers, which not only have good electrochemical performance, but also provide stability and corrosion resistance.

[0109] The choice of probe immobilization method directly affects the sensitivity and stability of the sensor. Commonly used probe immobilization methods include adsorption, self-assembly, biotin-avidin immobilization, covalent bonding, and cross-linking.

[0110] In the fields of biosensing or medical detection, depending on the properties of the analyte, the following probes can be considered: nucleic acid probes, protein probes, or enzyme probes. For nucleic acid probes, the stability and hybridization efficiency of the probe need to be considered. Covalent immobilization methods and self-assembly methods can provide strong immobilization strength and maintain the bioactivity of the probe. For protein or enzyme probes, it is necessary to consider maintaining their activity and selectivity. The biotin-avidin system and covalent bonding methods are commonly used immobilization methods that can provide stable binding and good maintenance of bioactivity.

[0111] In step S20, the analyte is diluted to an appropriate concentration according to experimental requirements, ensuring the homogeneity of the solution. Simultaneously, a precise micropipette is used to drop the solution onto electrode plate 11, avoiding spillage or uneven distribution.

[0112] After the test solution interacts with the probe, a potential change is generated on the electrode plate 11. The potential change is transferred to the FET transducer module through the MOSFET detection plug plate 4.

[0113] In step S30, the FET transducer module detects the potential change on the electrode plate 11 through its gate G; the signal conversion principle is as follows: the voltage change of the MOSFET gate G causes the current change between the source S and the drain D, thereby realizing the conversion of potential to current; the weak current change signal detected by the FET transducer module is amplified by the amplifier circuit board 3 to improve the signal strength and readability.

[0114] In step S40, the amplified detection signal is recorded using a data acquisition system. This data will be used for subsequent analysis and result output. Real-time or historical data of current changes are displayed using visualization devices, such as computer screens or charts. The recorded detection signal is analyzed to output the final detection result. Statistical and analytical software is used to process the data, identify the trend and pattern of signal changes, and interpret the properties and concentration of the analyte based on the analysis results to draw a detection conclusion.

[0115] The above description is merely a preferred embodiment of the present invention and does not limit the patent scope of the present invention. Any equivalent structural transformations made using the contents of the present invention's specification and drawings under the inventive concept of the present invention, or direct / indirect applications in other related technical fields, are included within the patent protection scope of the present invention.

Claims

1. A MOSFET biosensor based on an extended gate, characterized in that, It includes an extended gate electrode module, a FET transducer module, and an amplification circuit board, wherein the extended gate electrode module is detachably connected to the FET transducer module; The extended gate electrode module includes an electrode sheet, on which a detection probe is fixed for contacting the solution to be tested and transferring the potential change to the FET transducer module. The FET transducer module includes a MOSFET detection plug and a MOSFET. The electrode plate is plugged into the MOSFET detection plug, and the gate of the MOSFET is connected to the extended gate electrode module through the MOSFET detection plug, for converting the potential change into a change in current signal. The amplifier circuit board is electrically connected to the MOSFET detection plug-in, and is used to amplify the current signal of the MOSFET and output it as detection data; The MOSFET detection board includes a PCB board, an electrode holder, and terminals; the electrode holder is disposed at one end of the PCB board, and the electrode plate is inserted and connected to the electrode holder; the MOSFET is electrically connected to the PCB board. The electrode sheet includes a working electrode, an auxiliary electrode, and a reference electrode; The reference electrode is electrically connected to the power supply terminal of the amplifier circuit board via the terminal block and the first cable, and is used to supply power to the extended gate electrode module; the power supply terminal is a battery or an external power source, and the power supply terminal has a transformer for stable DC power supply; The working electrode, the auxiliary electrode, and the reference electrode are respectively connected to the terminal block, and the MOSFET is electrically connected to the working electrode through the terminal block; the working electrode and the auxiliary electrode are gold, platinum, or silver, and the reference electrode is silver chloride; The MOSFET is disposed on the amplification circuit board, and the MOSFET and the amplification circuit board are integrally formed to form an integrated detector; or, the MOSFET is soldered onto the MOSFET detection plug-in board.

2. The MOSFET biosensor based on an extended gate as described in claim 1, characterized in that, The MOSFET includes a main component and a source, a drain, and a gate disposed on the main component; the gate and the source are disposed on one side of the main component, and the drain is disposed on the other side of the main component; The main component is configured to switch from a cutoff state to a conduction state when the gate voltage reaches a threshold voltage.

3. The MOSFET biosensor based on an extended gate as described in claim 2, characterized in that, The main component is an insulating gate oxide, which is SiO2, Al2O3, HfO2 or Ta2O5; The source and the drain are electrically connected to the amplifier circuit board via the terminal block and the second cable, respectively.

4. A testing workstation, characterized in that, The invention includes a housing and a MOSFET biosensor based on an extended gate as described in any one of claims 1-3. The MOSFET biosensor based on an extended gate is packaged inside the housing. The housing is provided with a plug-in opening corresponding to the extended gate electrode module and at least one data interface. The plug-in opening is used to enable the plugging and unplugging of the extended gate electrode module and the FET transducer module. The data interface is used to enable the amplification circuit board to establish a data connection with the data processing terminal. The container is also equipped with a display component, which is electrically connected to the amplification circuit board for visually displaying the detection data.

5. A detection method, applicable to the MOSFET biosensor based on an extended gate as described in any one of claims 1-3, characterized in that, include: S10. Select a suitable method for fixing the electrode sheet and probe according to the properties of the analyte; S20. 50-100 μL of the test solution is dropped onto the electrode plate on which the probe is fixed, and the potential change of the electrode plate is transferred to the FET transducer module. S30. The potential change is converted into a current change detection signal by the FET transducer module, and the detection signal is amplified by the amplifier circuit board. S40. Record the amplified detection signal and display the current change through a visualization device. Analyze the detection signal to output the detection result.

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