Sensor system based on sheet magnetic label and GMR magnetic biochip

Abstract

The invention provides a sensor system based on a sheet magnetic tag and a GMR magnetic biochip, and relates to the technical field of electronic information. A signal acquisition plate of the structure is connected with a chip carrier plate, a biological chip is arranged on the chip carrier plate, the chip carrier plate is arranged in a pipe channel of a solenoid, the solenoid is arranged in a loading structure, a programmable power panel can provide a power supply for the solenoid, and the programmable power panel is connected with the chip carrier plate. The biological chip can capture the pathogenic bacteria modified by the sheet-shaped magnetic label; the signal acquisition board carries a constant current circuit and a signal acquisition circuit, the constant current circuit can provide constant current for the biochip, and the signal acquisition circuit can acquire, amplify and process a signal output by the biochip. According to the system, the sensitivity of the sensor system can be effectively improved, namely, high-sensitivity detection can be carried out on a low-concentration pathogenic bacterium sample, and output signals of a biological chip are prevented from being annihilated in the background of noise and the like.

Description

Technical Field

[0001] The present invention relates to the field of electronic information technology, and in particular to a sensor system based on a sheet-like magnetic label and a GMR magnetic biochip. Background Art

[0002] In recent years, advances in magnetoresistive materials and magnetic particles have led to the development of biosensors based on the GMR effect. Highly sensitive, micrometer-scale magnetic field sensors are fabricated using multilayer metal thin-film structures, whose resistance changes with an applied magnetic field. GMR biosensors exploit this effect to detect the presence and quantity of magnetic particles used in biological separation and purification, ultimately assessing microbial concentrations based on the number of these particles.

[0003] However, ordinary magnetic tags are small in size, with particle sizes usually at the nanometer level, and the additional magnetic field strength they generate is small, making the effective output signal of the GMR chip very weak. That is, the signal amplitude is usually at the μV level. The effective signal is often buried in strong background noise such as power frequency noise and its harmonics, excitation signal and its harmonics, resulting in inaccurate results. Summary of the Invention

[0004] The purpose of this specification is to provide a sensor system based on sheet-like magnetic labels and GMR magnetic biochips, which can solve the problem of inaccurate detection results of weak signals in traditional sensor systems.

[0005] The embodiments of this specification are implemented as follows:

[0006] A sensor system based on a sheet-like magnetic tag and a GMR magnetic biochip, comprising a programmable power supply board, a signal acquisition board, a chip carrier board, a solenoid, and a loading structure;

[0007] The signal acquisition board is connected to the chip carrier board, a biochip is provided on the chip carrier board, the chip carrier board is provided in the tube channel of the solenoid, the solenoid is provided in the loading structure, the programmable power supply board can provide power to the solenoid, and the biochip can capture pathogens modified with sheet-shaped magnetic labels;

[0008] The signal acquisition board is equipped with a constant current circuit and a signal acquisition circuit. The constant current circuit can provide a constant current for the biochip, and the signal acquisition circuit can acquire and amplify the signal output by the biochip.

[0009] The embodiments of this specification have at least the following advantages or beneficial effects:

[0010] Compared with the existing technology, this sensor system based on sheet magnetic labels and GMR magnetic biochips captures pathogens through sheet magnetic labels, and then uses the above-mentioned signal acquisition board to collect the magnetically captured pathogens. After amplification and processing by the constant current circuit and signal acquisition circuit, the sensitivity of the above-mentioned sensor system can be effectively improved, that is, low-concentration pathogenic bacteria samples can be detected with high sensitivity, avoiding the output signal of the biochip being buried in background noise. BRIEF DESCRIPTION OF THE DRAWINGS

[0011] In order to more clearly illustrate the technical solutions of the embodiments of this specification, the following is a brief introduction to the drawings required for use in the embodiments. It should be understood that the following drawings only illustrate certain embodiments of this specification and therefore should not be regarded as limiting the scope. For ordinary technicians in this field, other relevant drawings can be obtained based on these drawings without paying any creative work.

[0012] Figure 1 This is a schematic diagram of the connection of the sensor system based on the sheet-like magnetic label and the GMR magnetic biochip provided in this specification;

[0013] Figure 2 This is a schematic diagram of the structure of the signal acquisition board provided in this manual;

[0014] Figure 3 A circuit diagram of a constant current circuit provided in this specification;

[0015] Figure 4 A circuit diagram of the signal acquisition circuit provided in this manual;

[0016] Figure 5 A schematic diagram of the structure of the chip carrier provided in this specification;

[0017] Figure 6 This is a schematic diagram of the structure of the sensor system based on the sheet-like magnetic label and the GMR magnetic biochip provided in this specification;

[0018] Figure 7 Schematic diagram of the installation of the sensor system and chip carrier based on the sheet-like magnetic label and GMR magnetic biochip provided in this specification;

[0019] Figure 8 A schematic diagram of the structure of the chip carrier provided in this specification;

[0020] Figure 9 A front view of the limit plate provided for this instruction manual;

[0021] Figure 10 The installation diagram of the biochip provided in this manual;

[0022] Icons: 1. Signal acquisition board; 2. Chip carrier; 21. Electrode sheet; 3. Solenoid; 4. Loading structure; 5. Biochip; 6. Support plate; 7. Limit plate; 8. Handle; 9. Limit part; 10. Through slot; 11. Limit slot; 12. Buckle; 13. Switch button; 15. Pressing part. DETAILED DESCRIPTION

[0023] To make the objectives, technical solutions, and advantages of the embodiments of this specification more clear, the technical solutions in the embodiments of this specification will be clearly and completely described below in conjunction with the accompanying drawings of the embodiments of this specification. Obviously, the described embodiments are part of the embodiments of this specification, not all of the embodiments. Generally, the components of the embodiments of this specification described and shown in the drawings herein can be arranged and designed in a variety of different configurations.

[0024] Therefore, the following detailed description of the embodiments of the present specification provided in the accompanying drawings is not intended to limit the scope of the present specification as claimed, but merely represents selected embodiments of the present specification. Based on the embodiments in this specification, all other embodiments obtained by persons of ordinary skill in the art without making any creative effort are within the scope of protection of this specification.

[0025] It should be noted that similar reference numerals and letters denote similar items in the following drawings, and therefore, once an item is defined in one drawing, it does not need to be further defined and explained in subsequent drawings.

[0026] In the description of the embodiments of this specification, it should be noted that if the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer", etc. appear, the orientation or position relationship indicated is based on the orientation or position relationship shown in the accompanying drawings, or the orientation or position relationship in which the product of this specification is usually placed when in use. It is only for the convenience of describing this specification and simplifying the description, and does not indicate or imply that the device or component referred to must have a specific orientation, be constructed and operate in a specific orientation. Therefore, it should not be understood as a limitation on this specification. In addition, if the terms "first", "second", "third", etc. appear, they are only used to distinguish the description and should not be understood as indicating or implying relative importance.

[0027] Furthermore, the use of terms such as "horizontal," "vertical," and "overhanging" does not necessarily mean that the component must be absolutely horizontal or overhanging, but rather that it can be slightly tilted. For example, "horizontal" simply means that its direction is more horizontal than "vertical," not that the structure must be completely horizontal, but rather that it can be slightly tilted.

[0028] In the description of the embodiments of this specification, it should be noted that, unless otherwise expressly specified or limited, the terms "disposed," "installed," "connected," and "connected" should be understood in a broad sense. For example, they can refer to fixed connections, detachable connections, or integral connections; mechanical connections or electrical connections; direct connections or indirect connections through an intermediate medium; and internal connections between two components. Those skilled in the art will understand the specific meanings of the above terms in this specification based on specific circumstances.

[0029] Please refer to Figures 1 to 10 , a sensor system based on a sheet-shaped magnetic tag and a GMR magnetic biochip provided in one embodiment of the present specification mainly includes a programmable power supply board, a signal acquisition board 1, a chip carrier board 2, a solenoid 3 and a loading structure 4;

[0030] The signal acquisition board 1 is connected to the chip carrier 2. A biochip 5 is provided on the chip carrier 2. The chip carrier 2 is provided in the tube channel of the solenoid 3. The solenoid 3 is provided in the loading structure 4. The programmable power supply board can provide power to the solenoid 3. The biochip 5 can capture pathogens modified with sheet-shaped magnetic labels. The sheet-shaped magnetic labels can magnetically mark pathogens.

[0031] The signal acquisition board 1 is equipped with a constant current circuit and a signal acquisition circuit. The constant current circuit can provide a constant current to the biochip 5 , and the signal acquisition circuit can acquire and amplify the signal output by the biochip 5 .

[0032] In this embodiment, the biochip 5 is a GMR magnetic biochip.

[0033] In this embodiment, the preparation method of the sheet-like magnetic label is as follows:

[0034] preparing a graphene substrate, wherein the uniformity of the graphene on the graphene substrate meets preset requirements;

[0035] Magnetic iron oxide nanoparticles were prepared by synthesizing iron oleate precursor;

[0036] After modifying magnetic iron oxide nanoparticles with sodium citrate, the modified magnetic iron oxide nanoparticles are mixed with a graphene substrate in an aqueous phase to prepare a two-dimensional flexible magnetic aggregate. The magnetic strength of the two-dimensional flexible magnetic aggregate is determined by the loading amount of the modified magnetic iron oxide nanoparticles and the relative spacing of the modified magnetic iron oxide nanoparticles.

[0037] The detailed preparation methods of the above steps are as follows:

[0038] Preparation of graphene substrate: Graphene generated by chemical vapor deposition is deposited on the surface of copper foil to obtain a Gr / Gu sample; polymethyl methacrylate is coated on the side of the graphene of the Gr / Gu sample away from the copper foil, and after drying, a PMMA / Gr / Gu sample is obtained; the PMMA / Gr / Gu sample is immersed in an ammonium persulfate solution, and after removing the copper foil, the floating sample on the surface of the ammonium persulfate solution is fished out with a silicon wafer and dried to obtain a PMMA / Gr / SiO2 / Si sample; the PMMA / Gr / SiO2 / Si sample is immersed in an acetone solvent, and after removing the polymethyl methacrylate, a Gr / SiO2 / Si sample is obtained.

[0039] Preparation of magnetic iron oxide particles: ethanol, deionized water, and n-hexane are mixed to obtain a first mixed solution; ferric chloride hexahydrate and sodium oleate are added to the first mixed solution, refluxed, and then separated to obtain a n-hexane solution containing ferric oleate; the n-hexane in the n-hexane solution containing ferric oleate is evaporated to obtain an oily iron oleate mixture; the oily iron oleate mixture, octadecene, oleic acid, or sodium oleate are heated under a nitrogen atmosphere to react, cooled to room temperature, vented with air, and then isopropanol is added to obtain magnetic iron oxide nanoparticles. Specifically, the volume ratio of ethanol, deionized water, and n-hexane is 4:3:7. The volume of the first mixed solution is 100 mL. The added mass of ferric chloride hexahydrate is 2.7 g (molar mass 10 mmol), and the added mass of sodium oleate is 9.125 g (molar mass 30 mmol). The reaction was refluxed at 70°C for 4 hours to separate a reddish-brown n-hexane solution (containing iron oleate). The reddish-brown n-hexane solution was washed with 10 mL of deionized water, and the n-hexane was evaporated to obtain the iron oleate oily mixture. 9 g of the iron oleate oily mixture, 25 g of octadecene, and a certain amount of oleic acid or sodium oleate were added to a three-necked flask. Under a nitrogen atmosphere, the temperature was increased to 320°C at a rate of 3°C / min to 5°C / min, and the mixture was kept warm for 30 minutes with stirring during the holding period. The mixture was then cooled to room temperature, air was introduced into the three-necked flask, and 50 mL of isopropanol was added to precipitate magnetic iron oxide nanoparticles. The obtained magnetic iron oxide nanoparticles were centrifuged and washed (with a mixture of n-hexane and ethanol in a volume ratio of 1:5) three times, and then dispersed in n-hexane or toluene for later use.

[0040] Preparation of citric acid-modified magnetic iron oxide nanoparticles: The prepared magnetic iron oxide nanoparticles were precipitated with ethanol and then dispersed in tetrahydrofuran to obtain a dispersion solution. A sodium citrate solution was added to the dispersion solution, reacted under a nitrogen atmosphere, and centrifuged to obtain the modified magnetic iron oxide nanoparticles. Specifically, the magnetic iron oxide nanoparticles (including spherical, flaky, or rod-shaped magnetic iron oxide single particles) were surface-modified with sodium citrate via a ligand exchange method. Specifically, 10 mg of magnetic iron oxide single particles (spherical, flaky, or rod-shaped) were precipitated with ethanol and dispersed in 10 mL of tetrahydrofuran. Then, 5 mL of an aqueous sodium citrate solution (20 mg of sodium citrate solute) was added to the solution. The reaction was allowed to proceed at room temperature under nitrogen for 4 hours. After the reaction, the modified magnetic iron oxide single particles adhered to the bottom of the reaction flask or on a stirrer. The particles were then centrifuged and dispersed in deionized water. The modified magnetic iron oxide single particles in the aqueous phase were filtered through a 0.22 μm membrane for purification.

[0041] Preparation of sheet-like magnetic labels: Using the functionalized molecules on the surface of the graphene substrate prepared above as the coordination center, the magnetic iron oxide nanoparticles modified with citric acid are mixed with the graphene substrate in the aqueous phase to prepare two-dimensional flexible iron oxide, which is a sheet-like magnetic label.

[0042] In this embodiment, magnetically marking pathogens with the above-mentioned sheet-like magnetic labels can effectively enhance the detection sensitivity of the above-mentioned sensor system to pathogens, and then amplifying the collected pathogenic bacteria signals through the above-mentioned signal acquisition board 1 can further enhance the detection sensitivity of the above-mentioned sensor system, thereby preventing the signal from being annihilated by background noise.

[0043] In this embodiment, the programmable power supply board can provide power to the solenoid 3 , and the current of the solenoid 3 can be made variable by adjusting the power of the programmable power supply board, thereby generating an excitation magnetic field for the biochip 5 .

[0044] In this embodiment, the constant current circuit includes a first diode, a second diode, and a control resistor R G and the load resistor R L The first diode and the second diode are connected in series in the feedback loop D A To limit the range of the input signal, the control resistor R G , the load resistance R L and the biochip 5 are connected in series to control the output current of the current source to the biochip 5, the second diode and the load resistor R L Connected in parallel with the biochip 5 to stabilize the current of the biochip 5.

[0045] In this embodiment, the feedback loop D AAble to control the load resistance R L size.

[0046] In this embodiment, the constant current circuit can provide the biochip 5 with a constant current of 1 μA to 20 μA.

[0047] In this embodiment, the first diode and the second diode are arranged in series and in parallel with the biochip 5 to form the above-mentioned constant current circuit. When power is applied to the circuit, the diode will provide a relatively constant voltage when forward conducting. Due to the voltage characteristics of the diode, the voltage across the biochip 5 remains constant, thereby enabling the current of the biochip 5 to remain relatively constant.

[0048] In this embodiment, the signal acquisition circuit includes a first-stage operational amplifier, a second-stage operational amplifier and an AD converter. The input end of the first-stage operational amplifier is arranged in parallel with the biochip 5, and the output end of the second-stage operational amplifier is connected to the AD converter. The first-stage operational amplifier can differentially amplify the voltage signals at both ends of the biochip 5. The second-stage operational amplifier can buffer and stabilize the voltage signal output by the first-stage operational amplifier and serve as the input signal of the AD converter. The AD converter can convert the received analog voltage signal into a digital signal and output it to the host computer.

[0049] In this embodiment, the first-stage operational amplifier may preferably be INA333, and the second-stage operational amplifier may preferably be OPA333. Figure 4 shown.

[0050] In this embodiment, the above-mentioned signal acquisition circuit can amplify the input signal and process the voltage output by the biochip 5. The first-stage operational amplifier can perform high-precision differential amplification on the input signal, and the second-stage operational amplifier can buffer and stabilize the input signal, thereby acquiring and processing low-level signals.

[0051] In this embodiment, a plurality of electrode pads 21 are provided on one side of the chip carrier 2. These electrode pads 21 can provide power to the biochip 5. Specifically, the number of electrode pads 21 is preferably seven, providing a stable power supply to the biochip 5. The chip carrier 2 supports the biochip 5.

[0052] In this embodiment, a mounting hole and an insertion hole are provided on one side of the loading structure 4, and the solenoid 3 is provided in the mounting hole. The hole channel direction of the mounting hole is the same as the hole channel direction of the insertion hole, and the hole side wall of the insertion hole abuts against the inner wall of the spiral tube, and the insertion hole can be inserted into the chip carrier 2.

[0053] In this embodiment, the loading structure 4 may be a rectangular structure having dimensions of 450 mm × 212 mm × 250 mm (length × width × height). A display screen is mounted on the front of the loading structure 4, and the insertion hole is provided on the same side (i.e., a hole is provided at the shell position of the loading structure 4). The mounting hole is provided inside the loading structure 4, and the solenoid 3 is provided in the mounting hole.

[0054] In this embodiment, the display screen can be used to display and detect human-computer interaction software.

[0055] In this embodiment, the arrangement of the insertion holes and mounting holes enables the biochip 5 mounted on the chip carrier 2 to be positioned at the center of the solenoid 3, thereby making the magnetic field strength at the location of the biochip 5 controllable. Furthermore, this arrangement facilitates installation and removal of the chip carrier 2, enhancing portability while ensuring electrical connection with the main control system.

[0056] In this embodiment, a support plate 6 is provided on one side of the chip carrier 2, and the chip carrier 2 can be placed on one end of the support plate 6. A limiting plate 7 is provided on the end of the support plate 6 away from the chip carrier 2, and the setting direction of the limiting plate 7 is perpendicular to the setting direction of the support plate 6. A handle 8 is provided on the side of the limiting plate 7 away from the support plate 6.

[0057] In this embodiment, part of the above-mentioned support plate 6 can be stacked with the above-mentioned chip carrier 2, and the setting position of this part corresponds to the center position of the solenoid 3. The other part of the above-mentioned support plate 6 is a horizontal plate, and its length corresponds to the length from the center position of the solenoid 3 to the insertion hole position.

[0058] In this embodiment, the limiting plate 7 and the supporting plate 6 are provided so that the biochip 5 mounted on the chip carrier 2 can be in an upward state.

[0059] In this embodiment, a limit member 9 is provided on the support plate 6, and the setting direction of the limit member 9 is perpendicular to the setting direction of the support plate 6 and the setting direction of the limit plate 7, and the limit member 9 is provided with a through groove 10 on the side away from the support plate 6, and the limit plate 7 is provided with a limiting groove 11, and the limiting groove 11 is connected with the through groove 10, and the hole wall of the insertion hole is provided with a protrusion adapted to the through groove 10 and the limiting groove 11, and the support plate 6 can make the chip carrier 2 located at the center position of the solenoid 3 under the clamping action of the through groove 10 and the protrusion.

[0060] In this embodiment, the arrangement of the through groove 10 , the limiting groove 11 and the protrusion can prevent the biochip 5 from being deflected during the process of being installed and placed on the solenoid 3 .

[0061] In this embodiment, a plurality of latches 12 are provided on one end of the support plate 6 away from the limiting plate 7. The plurality of latches 12 are provided on opposite sides of the chip carrier 2 and can secure the chip carrier 2. The latches 12 on the opposite sides can further secure the chip carrier 2.

[0062] In this embodiment, the limit plate 7 is provided with a switch button 13, and the switch button 13 can control the fastening state of the buckle 12. In detail, the provision of multiple buckles 12 facilitates the installation or removal of the chip carrier 2 on the support plate 6.

[0063] In this embodiment, a pressing member 15 corresponding to the switch button 13 is provided on the side of the tray 6 away from the chip carrier 2, that is, by controlling the switch button 13, the pressing member 15 can be put into a pressed state. At this time, the buckle 12 is in an open state, which facilitates placing the chip carrier 2 on the tray 6 or removing the chip carrier 2 from the tray 6.

[0064] In this embodiment, the detection steps are described through the following examples:

[0065] (1) Place the GMR biochip 5 into the sensor system and record the data detected by the sensor system.

[0066] (2) A sheet-like magnetic label (concentration of 1 mg / mL, volume of 50 μL) was injected into 50 μL of pathogenic bacteria sample solution and incubated in a water bath incubator at 37°C for 10 min. During the incubation period, the reaction container was shaken every ten minutes to allow the solution to be fully mixed and reacted to obtain magnetically captured pathogens.

[0067] (3) The magnetically captured pathogenic bacteria were concentrated and enriched, that is, magnetic separation was performed for 1 minute using a magnetic separation instrument, and then the supernatant was removed and 70 μL PBS buffer was injected. This was repeated twice, and 20 μL of the bioconcentrated sample was retained to obtain the pathogenic bacteria modified with the sheet-like magnetic label.

[0068] (4) Use GMR biochip 5 to capture pathogens modified with magnetic labels, that is: the magnetically labeled pathogenic bacteria liquid (20 μL of biological concentrated sample) after magnetic separation is injected into the GMR chip microfluidics through a small syringe, and the immune reaction is carried out at room temperature of 37°C for 10 minutes, and then it is washed with PBS buffer for 5 times, and then naturally dried and left for detection.

[0069] (5) The GMR biochip 5 is placed back into the sensor system, and the data detected by the sensor system is recorded. By comparing the data detected in (1), it can be determined whether pathogens are present in the sample.

[0070] The chip that captured the pathogens was placed in the sensor system, and the data read was shown in the table below. The sensor system was designed to read the chip's voltage output at the 0.1μV level.

[0071] Table 1 Data read by the sensor system

[0072]

[0073] It can be seen from the above table that the above sensor system has high sensitivity and can effectively solve the problem of pathogenic bacteria signals being buried in background noise.

[0074] The above are merely preferred embodiments of this specification and are not intended to limit this specification. Those skilled in the art will readily appreciate that this specification is susceptible to various modifications and variations. Any modifications, equivalent substitutions, or improvements made within the spirit and principles of this specification shall be within the scope of protection of this specification.

Claims

1. A sensor system based on a sheet-like magnetic label and a GMR magnetic biochip, characterized in that: It includes a programmable power supply board, a signal acquisition board, a chip carrier board, a solenoid and a loading structure; The signal acquisition board is connected to the chip carrier board, a biochip is provided on the chip carrier board, the chip carrier board is provided in the tube channel of the solenoid, the solenoid is provided in the loading structure, the programmable power supply board can provide power to the solenoid, the biochip can capture pathogens modified with sheet-shaped magnetic labels, and the sheet-shaped magnetic labels can magnetically mark pathogens; The signal acquisition board is equipped with a constant current circuit and a signal acquisition circuit. The constant current circuit can provide a constant current for the biochip, and the signal acquisition circuit can acquire and amplify the signal output by the biochip.

2. The sensor system based on sheet-like magnetic labels and GMR magnetic biochips according to claim 1, characterized in that: The constant current circuit includes a first diode, a second diode, and a control resistor R G and the load resistor R L The first diode and the second diode are connected in series in the feedback loop D A To limit the range of the input signal, the control resistor R G , the load resistance R L and the biochip in series to control the output current of the current source to the biochip, the second diode and the load resistor R L The biochip is connected in parallel to stabilize the current of the biochip.

3. The sensor system based on sheet-like magnetic labels and GMR magnetic biochips according to claim 1, characterized in that: The constant current circuit can provide a constant current of 1 μA to 20 μA for the biochip.

4. The sensor system based on sheet-like magnetic labels and GMR magnetic biochips according to claim 1, characterized in that: The signal acquisition circuit includes a first-stage operational amplifier, a second-stage operational amplifier and an AD converter. The input end of the first-stage operational amplifier is arranged in parallel with the biochip, and the output end of the second-stage operational amplifier is connected to the AD converter. The first-stage operational amplifier can differentially amplify the voltage signals at both ends of the biochip. The second-stage operational amplifier can buffer and stabilize the voltage signal output by the first-stage operational amplifier and serve as the input signal of the AD converter. The AD converter can convert the received analog voltage signal into a digital signal and output it to the host computer.

5. The sensor system based on sheet-like magnetic labels and GMR magnetic biochips according to claim 1, characterized in that: A plurality of electrode sheets are provided on one side of the chip carrier, and the plurality of electrode sheets can provide power for the biochip.

6. The sensor system based on sheet-like magnetic labels and GMR magnetic biochips according to claim 1, characterized in that: A mounting hole and an insertion hole are provided on one side of the loading structure. The solenoid is provided in the mounting hole. The hole channel direction of the mounting hole is the same as the hole channel direction of the insertion hole, and the hole side wall of the insertion hole abuts against the inner wall of the solenoid. The insertion hole can be inserted into the chip carrier.

7. The sensor system based on sheet-like magnetic labels and GMR magnetic biochips according to claim 6, characterized in that: A pallet is provided on one side of the chip carrier, one end of the pallet can be used to place the chip carrier, a limit plate is provided on the end of the pallet away from the chip carrier, the setting direction of the limit plate is perpendicular to the setting direction of the pallet, and a handle is provided on the side of the limit plate away from the pallet.

8. The sensor system based on sheet-like magnetic labels and GMR magnetic biochips according to claim 7, characterized in that: A limit piece is provided on the support plate, and the setting direction of the limit piece is perpendicular to the setting direction of the support plate and the setting direction of the limit plate, and a through groove is provided on the side of the limit piece away from the support plate, and the limit plate is provided with a limiting groove, and the limiting groove is connected with the through groove, and the hole wall of the insertion hole is provided with a protrusion adapted to the through groove and the limiting groove, and the support plate can make the chip carrier be located at the center position of the solenoid under the clamping action of the through groove and the protrusion.

9. The sensor system based on sheet-like magnetic labels and GMR magnetic biochips according to claim 8, characterized in that: A plurality of buckles are provided at one end of the support plate away from the limiting plate. The plurality of buckles are provided on two opposite sides of the chip carrier, and the plurality of buckles can fix the chip carrier.

10. The sensor system based on sheet-like magnetic labels and GMR magnetic biochips according to claim 9, characterized in that: The limiting plate is provided with a switch button, and the switch button can control the fastening state of the buckle.

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