Portable high-flux microparticle rapid detection device and method

Abstract

The invention provides a portable high-flux microparticle rapid detection device and method. The device comprises a *-shaped structure chip and a signal processing system, eight symmetrically-distributed detection areas are arranged in the chip of the star-shaped structure, when microparticles in a sample solution move and pass through the detection areas, the microparticles can replace solutions with the same volume, the total resistance value of the solutions in the detection areas is changed, a pulse signal is formed, the volumes of the solutions replaced by the microparticles with different types and sizes are different, and the pulse signal is obtained. The generated pulse signals are different, so that the chip can be used for detecting and counting the types, the sizes and the quantity of microparticles in a channel of the micro-fluidic chip; and the signal processing system can realize real-time acquisition, processing and transmission of signals. According to the device, the original solution resistance value is effectively eliminated, and noise signals of other frequencies are inhibited; and meanwhile, the equipment is simple to operate, small and portable, and can be used for carrying out label-free and lossless rapid high-quantity detection on target particles of different types and sizes anytime and anywhere.

Description

Technical Field

[0001] The present invention relates to the technical fields of impedance pulse technology, Internet transmission technology, and microparticle analysis technology. Specifically, it particularly relates to a portable high-throughput rapid microparticle detection device and method. Background Art

[0002] Marine microparticles refer to tiny particles or microparticles existing in the marine environment, mainly including marine microplastics, microalgae, suspended organic matter, etc. These microparticles play important roles in the marine ecosystem. They may affect the growth of marine organisms, the food chain, biogeochemical processes, and the spread of pollutants. When microalgae are transported by ocean currents to suitable environmental conditions, they will rapidly reproduce and release toxins, leading to shellfish poisoning, fish death, and even threatening human health. Microplastics, due to their non-degradable characteristics, exist in the ocean for a long time and ultimately affect human health through the food chain. Therefore, the research and detection of marine microparticles are of great significance for protecting the marine ecological environment and human health.

[0003] Currently, the detection and analysis methods of marine microparticles mainly include visual analysis method, Raman spectroscopy method, and flow cytometry method. Although these methods can detect samples and analyze the characteristic information contained therein, they have certain limitations in practical applications. The visual analysis method relies on manual observation, with low detection accuracy and low efficiency; the Raman spectroscopy method requires complex equipment and professional operators, and has high requirements for the pretreatment of samples; the flow cytometry method requires fluorescence labeling, with complex operation steps and expensive equipment. These methods usually require a large amount of samples and reagents, with low detection efficiency and are difficult to meet the needs of rapid and high-throughput detection.

[0004] Existing microparticle detection methods have many defects. First of all, most of these methods require complex pretreatment of samples, increasing the detection time and cost. Secondly, the equipment is expensive and bulky, not convenient for carrying and on-site detection, restricting its flexibility in practical applications. In addition, these methods usually require professional operators and precise optical systems, with high requirements for the experimental environment and conditions, and are difficult to use in the wild or environments with limited resources. Finally, the detection efficiency is low, unable to meet the needs of rapid and high-throughput detection, and difficult to monitor the dynamic changes of microparticles in real time. Therefore, it is of great practical significance to develop a microparticle detection method with less consumption of samples and reagents, low cost, small structure, simple operation, and no need for labeling.

[0005] Impedance pulse technology is beneficial to the electrical properties of cells. It can evaluate the cell state in a label-free manner. The operating device can be highly integrated and miniaturized, and the operation process is simple and does not require a precise optical system. Due to its unique advantages, it has received increasing attention. The micro-particle detection method based on this is an emerging single-cell analysis and particle counting technology. It utilizes the electrical properties of particles and provides rich information for detection and analysis through the perturbation of the electric field caused by the flow of particles in the microfluidic channel, and has wide application value. Summary of the Invention

[0006] According to the above-mentioned technical problems, a portable high-throughput micro-particle rapid detection device and method are provided. The device of the present invention is simple to operate, light and portable, and does not require labeling of micro-particles, and can achieve rapid, accurate, and high-throughput rapid detection.

[0007] The technical means adopted by the present invention are as follows:

[0008] A portable high-throughput micro-particle rapid detection device, comprising: a rice-shaped structure chip and a signal processing system, wherein:

[0009] The rice-shaped structure chip includes a glass substrate layer, a metal electrode layer, and a PDMS cover layer, wherein:

[0010] The glass substrate layer serves as a support and insulating substrate;

[0011] The metal electrode layer is deposited on the glass substrate layer, and paired metal electrodes are provided on the metal electrode layer;

[0012] The PDMS cover layer is bonded to the glass substrate layer, and a microchannel layer is recessed on the PDMS cover layer; wherein:

[0013] The microchannel layer includes a sample inlet, a microfluidic channel, a detection area, and an outlet area, wherein:

[0014] The microfluidic channel includes a reference channel and a plurality of detection channels. The reference channel is used to provide a reference signal, and the detection channels are used to detect micro-particles in the sample;

[0015] The detection area includes a reference detection area and a plurality of sample detection areas. The reference detection area is connected to the reference channel, and each sample detection area is respectively connected to the corresponding detection channel;

[0016] The outlet area includes a reference sample outlet and a plurality of sample outlets, all of which are used to discharge the detected solution. Among them, the reference sample outlet is connected to the outflow port of the reference channel, and each sample outlet is connected to the outflow port of the corresponding detection channel;

[0017] The metal electrode is arranged at the center of the detection area, used to detect the resistance value of the solution and the impedance change caused by particles, generate pulse signals, and achieve rapid detection of microparticles;

[0018] The signal processing system, connected to the metal electrode, is used to collect, process, and transmit detection signals, including an STM32 minimum circuit, an AD5933 impedance detection circuit, an ESP32 transmission circuit, an analog / digital conversion circuit, and a filtering circuit.

[0019] Further, in the microchannel layer, the number of detection channels is the same as the number of sample detection areas and sample outlets, specifically:

[0020] The detection channels include a first detection channel, a second detection channel, a third detection channel, a fourth detection channel, a fifth detection channel, a sixth detection channel, and a seventh detection channel;

[0021] The sample detection areas include a first sample detection area, a second sample detection area, a third sample detection area, a fourth sample detection area, a fifth sample detection area, a sixth sample detection area, and a seventh sample detection area;

[0022] The sample outlets include a first sample outlet, a second sample outlet, a third sample outlet, a fourth sample outlet, a fifth sample outlet, a sixth sample outlet, and a seventh sample outlet;

[0023] The specific connection relationship is as follows:

[0024] The first detection channel is connected to the first sample detection area, and the first sample outlet communicates with the outflow port of the first detection channel; the second detection channel is connected to the second sample detection area, and the second sample outlet communicates with the outflow port of the second detection channel; the third detection channel is connected to the third sample detection area, and the third sample outlet communicates with the outflow port of the third detection channel; the fourth detection channel is connected to the fourth sample detection area, and the fourth sample outlet communicates with the outflow port of the fourth detection channel; the fifth detection channel is connected to the fifth sample detection area, and the fifth sample outlet communicates with the outflow port of the fifth detection channel; the sixth detection channel is connected to the sixth sample detection area, and the sixth sample outlet communicates with the outflow port of the sixth detection channel; the seventh detection channel is connected to the seventh sample detection area, and the seventh sample outlet communicates with the outflow port of the seventh detection channel.

[0025] Further, the widths of the reference channel, the first detection channel, the second detection channel (8), the third detection channel, the fourth detection channel, the fifth detection channel, the sixth detection channel, the seventh detection channel, the reference sample outlet, the first sample outlet, the second sample outlet, the third sample outlet, the fourth sample outlet, the fifth sample outlet, the sixth sample outlet, and the seventh sample outlet are all the same, all being 80 μm, and they are located on the same plane.

[0026] Further, the specifications of the reference detection area, the first sample detection area, the second sample detection area, the third sample detection area, the fourth sample detection area, the fifth sample detection area, the sixth sample detection area, and the seventh sample detection area are the same, with a length of 30 μm and a width of 15 μm for all, and the connection between the reference detection area and the reference sample outlet is in a closed state.

[0027] Further, there are angles between the reference channel, the first detection channel, the second detection channel, the third detection channel, the fourth detection channel, the fifth detection channel, the sixth detection channel, and the seventh detection channel, and the angles are all 45°.

[0028] Further, the widths of the metal electrodes are all 10 μm, and the heights are all 200 nm.

[0029] Further, the metal electrodes are made of gold material and are fabricated by physical vapor deposition process.

[0030] Further, the PDMS cover layer is made of PDMS material and is fabricated by photolithography casting process.

[0031] The present invention also provides a rapid micro-particle detection method implemented based on the portable high-throughput micro-particle rapid detection device, including:

[0032] S1. After cleaning the rice-shaped structure chip in the portable high-throughput micro-particle rapid detection device, connect the signal processing system in the portable high-throughput micro-particle rapid detection device by using through-hole pins.

[0033] S2. First, drop a certain amount of PBS buffer solution into the sample inlet, and then inject the sample to be detected into the sample inlet with a syringe.

[0034] S3. Connect the sample inlet, the reference sample outlet, each sample outlet, and the signal processing system with wires, turn on the power switch, and detect the sample to be detected.

[0035] S4. The number of detected voltage pulse signals is equal to the number of particles, which are collected and converted by the signal processing system and transmitted to the cloud for recording. The detection data and the number of particles are displayed in real time through the small program on the mobile phone.

[0036] Compared with the prior art, the present invention has the following advantages:

[0037] 1. The portable high-throughput microparticle rapid detection device provided by the present invention adopts a rice-shaped structure chip. There are eight symmetrically distributed detection areas in the chip. When the microparticles in the sample solution pass through the detection area, they will replace the solution of equal volume, so that the total resistance of the solution in the detection area changes, forming a pulse signal. The pulse signals generated by microparticles of different types and sizes are different, and multiple microparticles can be detected at the same time, which significantly improves the detection efficiency and realizes high-throughput detection. At the same time, the structural design enables the device to distinguish microparticles of different sizes, shapes and electrical properties, providing a high-resolution particle analysis method.

[0038] 2. The present invention provides a portable high-throughput microparticle rapid detection device, whose metal electrode layer is made of gold material through physical vapor deposition process and is located in the center of the detection area. The gold material electrode has good conductivity and stability. The physical vapor deposition process can accurately control the size and shape of the electrode to ensure the uniformity and consistency of the electrode. The design of this metal electrode layer can improve the sensitivity and accuracy of detection, so that the device can detect tiny impedance changes, thereby achieving high-precision detection of microparticles.

[0039] 3. The present invention provides a portable high-throughput microparticle rapid detection device, wherein the PDMS cover layer is made by a photolithography casting process. The PDMS material has good biocompatibility and optical transparency. The photolithography casting process can accurately manufacture the microchannel structure to ensure that the size and shape of the microchannel meet the design requirements.

[0040] 4. The present invention provides a portable high-throughput microparticle rapid detection device, in which a microchannel layer includes a liquid inlet, a microfluidic channel, a detection area and a liquid outlet area. The microfluidic channel includes a reference channel and multiple detection channels. The design of this microchannel layer can ensure the stable flow of the sample solution, reduce sample loss and cross contamination, and improve the reliability and repeatability of the detection.

[0041] 5. The present invention provides a portable high-throughput microparticle rapid detection device, whose signal processing system can effectively eliminate the original solution resistance, suppress noise signals of other frequencies, and improve the signal-to-noise ratio. At the same time, the system can collect and process the detection signal in real time, and send the data to the cloud through wireless transmission. Users can view the detection data and particle count in real time through the applet, realizing the automation and intelligence of the detection process.

[0042] 6. A portable high-throughput rapid microparticle detection device provided by the present invention is designed to be small and portable as a whole. It can be used by being paired with a mobile power supply, and has no excessive requirements for the experimental location and environmental conditions. Users can perform detections at any location where needed, without being restricted by laboratory conditions. This portability enables the device to be applicable to various detection scenarios such as the field and on-site, can quickly respond to and handle sudden environmental problems, and improves the flexibility and practicality of detection.

[0043] 7. A portable high-throughput rapid microparticle detection device provided by the present invention adopts impedance pulse technology, without the need for fluorescence labeling or other pretreatment of samples, avoiding the cost increase and operation complexity brought by fluorescence labeling, and reducing the detection cost. At the same time, label-free detection reduces the sample processing steps, shortens the detection time, improves the detection efficiency, and enables the device to quickly and efficiently complete the detection work of microparticles.

[0044] 8. A portable high-throughput rapid microparticle detection device provided by the present invention integrates multiple detection channels and reference channels on the same chip. Combined with a signal processing system, it realizes the integration of multiple functions. It can not only detect the types, sizes, and quantities of microparticles, but also monitor the dynamic processes of microparticles in real time. This multi-functional integrated design enables the device to meet various detection requirements and improves the versatility and applicability of the device.

[0045] Based on the above reasons, the present invention can be widely promoted in the fields of impedance pulse technology, Internet transmission technology, and microparticle analysis. BRIEF DESCRIPTION OF THE DRAWINGS

[0046] In order to more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the following will briefly introduce the drawings required for the description of the embodiments or the prior art. Obviously, the drawings in the following description are some embodiments of the present invention. For those of ordinary skill in the art, other drawings can be obtained based on these drawings without creative efforts.

[0047] Figure 1 It is a schematic diagram of the overall structure of the device of the present invention.

[0048] Figure 2 It is a schematic diagram of the structure of the rice-shaped chip of the device of the present invention.

[0049] In the figure: 1. Glass base layer; 2. Metal electrode layer; 3. PDMS cover layer; 4. Microchannel layer; 5. Sample inlet; 6. Reference channel; 7. First detection channel; 8. Second detection channel; 9. Third detection channel; 10. Fourth detection channel; 11. Fifth detection channel; 12. Sixth detection channel; 13. Seventh detection channel; 14. Reference detection area; 15. First sample detection area; 16. Second sample detection area; 17. Third sample detection area; 18. Fourth sample detection area; 19. Fifth sample detection area; 20. Sixth sample detection area; 21. Seventh sample detection area; 22. Reference detection sample outlet; 23. First sample outlet; 24. Second sample outlet; 25. Third sample outlet; 26. Fourth sample outlet; 27. Fifth sample outlet; 28. Sixth sample outlet; 29. Eighth sample outlet; 30. Included angle; 31. Signal processing system; 32. Straight pin. Detailed implementation manners

[0050] It should be noted that, without conflict, the embodiments in the present invention and the features in the embodiments may be combined with each other. The present invention will be described in detail below with reference to the accompanying drawings and in combination with the embodiments.

[0051] To make the objectives, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part rather than all of the embodiments of the present invention. The following description of at least one exemplary embodiment is actually illustrative only and in no way restrictive of the present invention and its application or use. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts shall fall within the protection scope of the present invention.

[0052] It should be noted that the terms used herein are only for describing specific implementation manners and are not intended to limit the exemplary embodiments according to the present invention. As used herein, unless otherwise clearly specified by the context, the singular form is also intended to include the plural form. In addition, it should be understood that when the terms "include" and / or "comprise" are used in this specification, they indicate the presence of the described features, steps, operations, devices, components and / or their combinations.

[0053] Unless otherwise specifically stated, the relative arrangement of components and steps, numerical expressions, and numerical values set forth in these embodiments do not limit the scope of the present invention. At the same time, it should be clear that, for the sake of convenience in description, the dimensions of the various parts shown in the drawings are not drawn in actual proportional relationships. Technologies, methods, and devices known to those of ordinary skill in the relevant art may not be discussed in detail, but where appropriate, such technologies, methods, and devices should be regarded as part of the authorization specification. In all the examples shown and discussed here, any specific values should be construed as merely exemplary and not as a limitation. Therefore, other examples of the exemplary embodiments may have different values. It should be noted that like reference numerals and letters denote like items in the following drawings, and thus, once an item is defined in one drawing, it does not need to be further discussed in subsequent drawings.

[0054] In the description of the present invention, it should be understood that the orientation or positional relationships indicated by orientation words such as "front, rear, upper, lower, left, right", "lateral, vertical, perpendicular, horizontal", and "top, bottom", etc., are generally based on the orientation or positional relationships shown in the drawings. These are only for the convenience of describing the present invention and simplifying the description. Without contrary statements, these orientation words do not indicate or imply that the devices or elements referred to must have a specific orientation or be constructed and operated in a specific orientation. Therefore, they should not be construed as limiting the scope of protection of the present invention. The orientation words "inner, outer" refer to the inside and outside relative to the contour of each component itself.

[0055] For the convenience of description, spatial relative terms such as "above...", "over...", "on the upper surface of...", "above", etc., can be used here to describe the spatial positional relationships between a device or feature shown in the drawings and other devices or features. It should be understood that the spatial relative terms are intended to encompass different orientations in use or operation in addition to the orientation described in the drawings for the device. For example, if the device in the drawing is inverted, the device described as "above other devices or structures" or "over other devices or structures" will then be positioned as "below other devices or structures" or "beneath other devices or structures". Thus, the exemplary term "above..." can include both the orientations of "above..." and "below...". The device can also be positioned in other different ways (rotated 90 degrees or in other orientations), and corresponding interpretations should be made for the spatial relative descriptions used here.

[0056] In addition, it should be noted that the use of words such as "first", "second", etc. to define components is only for the convenience of differentiating the corresponding components. Without additional statements, the above words have no special meanings. Therefore, they should not be construed as limiting the scope of protection of the present invention.

[0057] Such as Figure 1 、2 As shown in the figure, the present invention provides a portable high-throughput micro-particle rapid detection device, including: a rice-shaped structure chip and a signal processing system 31, where:

[0058] The rice-shaped structure chip includes a glass substrate layer 1, a metal electrode layer 2, and a PDMS cover layer 3, where:

[0059] The glass substrate layer 1 serves as a support and insulation substrate;

[0060] The metal electrode layer 2 is deposited on the glass substrate layer 1, and paired metal electrodes are provided on the metal electrode layer 2;

[0061] The PDMS cover layer 3 is bonded to the glass substrate layer 1, and a microchannel layer 4 is recessed on the PDMS cover layer 3; where:

[0062] The microchannel layer 4 includes a sample inlet 5, a microfluidic channel, a detection area, and an outlet area, where:

[0063] The microfluidic channel includes a reference channel 6 and a plurality of detection channels. The reference channel 6 is used to provide a reference signal, and the detection channels are used to detect micro-particles in the sample;

[0064] The detection area includes a reference detection area 14 and a plurality of sample detection areas. The reference detection area 14 is connected to the reference channel 6, and each sample detection area is respectively connected to the corresponding detection channel;

[0065] The outlet area includes a reference sample detection outlet 22 and a plurality of sample outlets, all of which are used to discharge the detected solution. Among them, the reference sample detection outlet 22 is connected to the outflow port of the reference channel 6, and each sample outlet is connected to the outflow port of the corresponding detection channel;

[0066] The metal electrode is arranged at the center of the detection area, used to detect the resistance value of the solution and the impedance change caused by particles, generate a pulse signal, and realize the rapid detection of micro-particles;

[0067] The signal processing system is connected to the metal electrode, used to collect, process, and transmit detection signals, including an STM32 minimum circuit, an AD5933 impedance detection circuit, an ESP32 transmission circuit, an analog / digital conversion circuit, and a filtering circuit.

[0068] In specific implementation, as a preferred implementation manner of the present invention, continue to refer to Figure 2 , in the microchannel layer 4, the number of detection channels is the same as the number of sample detection areas and sample outlets, specifically:

[0069] The detection channels include a first detection channel 7, a second detection channel 8, a third detection channel 9, a fourth detection channel 10, a fifth detection channel 11, a sixth detection channel 12, and a seventh detection channel 13;

[0070] The sample detection areas include a first sample detection area 15, a second sample detection area 16, a third sample detection area 17, a fourth sample detection area 18, a fifth sample detection area 19, a sixth sample detection area 20, and a seventh sample detection area 21;

[0071] The sample outlets include a first sample outlet 23, a second sample outlet 24, a third sample outlet 25, a fourth sample outlet 26, a fifth sample outlet 27, a sixth sample outlet 28, and a seventh sample outlet 29;

[0072] The specific connection relationships are as follows:

[0073] The first detection channel 7 is connected to the first sample detection area 15, and the first sample outlet 23 communicates with the outflow port of the first detection channel 7; the second detection channel 8 is connected to the second sample detection area 16, and the second sample outlet 24 communicates with the outflow port of the second detection channel 8; the third detection channel 9 is connected to the third sample detection area 17, and the third sample outlet 25 communicates with the outflow port of the third detection channel 9; the fourth detection channel 10 is connected to the fourth sample detection area 18, and the fourth sample outlet 26 communicates with the outflow port of the fourth detection channel 10; the fifth detection channel 11 is connected to the fifth sample detection area 19, and the fifth sample outlet 27 communicates with the outflow port of the fifth detection channel 11; the sixth detection channel 12 is connected to the sixth sample detection area 20, and the sixth sample outlet 28 communicates with the outflow port of the sixth detection channel 12; the seventh detection channel 13 is connected to the seventh sample detection area 21, and the seventh sample outlet 29 communicates with the outflow port of the seventh detection channel 13.

[0074] In this embodiment, the sample solution is injected from the sample inlet 5 and flows towards the reference channel 6, the first detection channel 7, the second detection channel 8, the third detection channel 9, the fourth detection channel 10, the fifth detection channel 11, the sixth detection channel 12, and the seventh detection channel 13 under the action of the flow field and the electric field force; the solution flows through the reference channel 6 to reach the reference detection area 14, and the metal electrode in the reference detection area 14 will detect the resistance value of the solution; the particles flow through the first sample detection area 15, the second sample detection area 16, the third sample detection area 17, the fourth sample detection area 18, the fifth sample detection area 19, the sixth sample detection area 20 to the seventh sample detection area 21, and will correspondingly replace the equal-volume solution in the detection area, causing impedance changes and generating corresponding pulse signals. The metal electrodes on the metal electrode layer 2 will transmit the collected solution resistance value and pulse signals to the signal processing module to complete the detection of the particle signals. The particles passing through the detection area flow out from the reference sample detection outlet 22, the first sample outlet 23, the second sample outlet 24, the third sample outlet 25, the fourth sample outlet 26, the fifth sample outlet 27, the sixth sample outlet 28 to the seventh sample outlet 29.

[0075] During specific implementation, as a preferred implementation manner of the present invention, continue to refer to Figure 2 , the widths of the reference channel 6, the first detection channel 7, the second detection channel 8, the third detection channel 9, the fourth detection channel 10, the fifth detection channel 11, the sixth detection channel 12, the seventh detection channel 13, the reference sample detection outlet 22, the first sample outlet 23, the second sample outlet 24, the third sample outlet 25, the fourth sample outlet 26, the fifth sample outlet 27, the sixth sample outlet 28, and the seventh sample outlet 29 are all the same, all being 80 μm, and they are located on the same plane.

[0076] During specific implementation, as a preferred implementation manner of the present invention, the specifications of the reference detection area 14, the first sample detection area 15, the second sample detection area 16, the third sample detection area 17, the fourth sample detection area 18, the fifth sample detection area 19, the sixth sample detection area 20, and the seventh sample detection area 21 are the same. The lengths are all 30 μm, the widths are all 15 μm, and the connection between the reference detection area 14 and the reference sample detection outlet 22 is in a closed state.

[0077] During specific implementation, as a preferred implementation manner of the present invention, continue to refer to Figure 2, an included angle 30 is provided between the reference channel 6, the first detection channel 7, the second detection channel 8, the third detection channel 9, the fourth detection channel 10, the fifth detection channel 11, the sixth detection channel 12, and the seventh detection channel 13, and the included angle 30 is 45° for all.

[0078] In specific implementation, as a preferred implementation manner of the present invention, the widths of the metal electrodes are all 10 μm, and the heights are all 200 nm.

[0079] In specific implementation, as a preferred implementation manner of the present invention, the metal electrode is made of gold material and is fabricated by physical vapor deposition process. The fabrication process includes the following steps:

[0080] Cleaning: Rinse the glass substrate with running water and dry it with high-pressure nitrogen.

[0081] Spin coating: Spin coat the photoresist above the clean glass substrate.

[0082] Exposure: Place the chromium plate with the chip structure pattern on the silicon wafer for exposure, and the exposure time is 20 s.

[0083] Development: Put the exposed glass substrate into the developer for development, and clean it to obtain the main mold of the glass substrate.

[0084] Deposition: Place the main mold of the glass substrate in the vacuum chamber, and deposit 200-nm-thick gold on the glass substrate by physical vapor deposition method.

[0085] Lift-off: Heat the 30% NaOH solution at 130 °C for 5 min, then put the main mold of the glass substrate with photoresist attached into the NaOH solution, immerse it for 3 min and then take it out, strip the photoresist on the substrate, clean and dry it to obtain the glass substrate with the metal electrode structure.

[0086] In specific implementation, as a preferred implementation manner of the present invention, the PDMS cover layer (3) is made of PDMS material and is fabricated by photolithography casting process. The fabrication process includes the following steps:

[0087] Cleaning: Rinse the silicon wafer with running water and dry it with high-pressure nitrogen.

[0088] Spin coating: Spin coat the photoresist above the clean silicon wafer.

[0089] Exposure: Place the mask with the chip structure pattern on the silicon wafer for exposure, and the exposure time is 10 s.

[0090] Development: Put the exposed silicon wafer into the developer for development, and clean it to obtain the main mold.

[0091] Vacuum pumping: Pour liquid PDMS and a curing agent into a clean glass cup at a ratio of 10:1, stir evenly with a stirring rod, then place it in a vacuum chamber and let it stand to remove the air in the glass cup to prevent bubbles from forming after PDMS curing.

[0092] Pouring and curing: After vacuum pumping is completed, pour PDMS onto the substrate of the main mold of the device chip, then place it in an oven and let it stand until PDMS cures.

[0093] Cleaning: Trim the cured PDMS chip according to the graphic size, use a punch to punch holes in the inlet and outlet of the chip, and then place the chip and the glass substrate with deposited metal electrodes in a plasma cleaner for cleaning.

[0094] Bonding: Take out the glass substrate and the PDMS chip from the plasma cleaner and bond them quickly.

[0095] The present invention also provides a rapid micro-particle detection method implemented based on the portable high-throughput micro-particle rapid detection device, including:

[0096] S1. After cleaning the rice-shaped structure chip in the portable high-throughput micro-particle rapid detection device, connect it to the signal processing system 31 in the portable high-throughput micro-particle rapid detection device by using a straight pin 32.

[0097] S2. First, drop a certain amount of PBS buffer solution into the sample inlet 5, and then inject the sample to be detected into the sample inlet 5 with a syringe.

[0098] S3. Connect the sample inlet 5, the reference sample detection outlet 22, each sample outlet and the signal processing system 31 with wires, turn on the power switch, and detect the sample to be detected.

[0099] S4. The number of detected voltage pulse signals is equal to the number of particles. The signal processing system collects, performs analog-to-digital conversion and transmits it to the cloud for recording, and the detection data and the number of particles are displayed in real time through a small program on the mobile phone side.

[0100] The present invention realizes rapid detection of unlabeled and untreated micro-particles. More importantly, it can provide high-resolution and high-flow particle analysis, distinguish micro-particles of different sizes, shapes and electrical properties, count the number of particles, making it possible to integrate multiple functions on the same chip. At the same time, the device is small, portable and easy to operate, facilitating rapid detection.

[0101] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those of ordinary skill in the art should understand that they can still modify the technical solutions described in the foregoing embodiments, or perform equivalent replacements on some or all of the technical features; and these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A portable high-throughput rapid micro-particle detection device, characterized in that, Comprising: An M-shaped structure chip and a signal processing system (31), wherein: The M-shaped structure chip includes a glass substrate layer (1), a metal electrode layer (2), and a PDMS cover layer (3), wherein: The glass substrate layer (1) serves as a support and insulating substrate; The metal electrode layer (2) is deposited on the glass substrate layer (1), and paired metal electrodes are provided on the metal electrode layer (2); The PDMS cover layer (3) is bonded to the glass substrate layer (1), and a microchannel layer (4) is recessed on the PDMS cover layer (3); wherein: The microchannel layer (4) includes a sample inlet (5), a microfluidic channel, a detection area, and an outlet area, wherein: The microfluidic channel includes a reference channel (6) and a plurality of detection channels. The reference channel (6) is used to provide a reference signal, and the detection channels are used to detect micro-particles in the sample; The detection area includes a reference detection area (14) and a plurality of sample detection areas. The reference detection area (14) is connected to the reference channel (6), and each sample detection area is respectively connected to a corresponding detection channel; The outlet area includes a reference sample detection outlet (22) and a plurality of sample outlets, all of which are used to discharge the detected solution. Among them, the reference sample detection outlet (22) communicates with the outflow port of the reference channel (6), and each sample outlet communicates with the outflow port of the corresponding detection channel; The metal electrode is arranged at the central position of the detection area, used to detect the resistance value of the solution and the impedance change caused by particles, generate a pulse signal, and achieve rapid detection of micro-particles; The signal processing system is connected to the metal electrode, used to collect, process, and transmit detection signals, and includes an STM32 minimum circuit, an AD5933 impedance detection circuit, an ESP32 transmission circuit, an analog / digital conversion circuit, and a filtering circuit.

2. The portable high-throughput microparticle rapid detection device according to claim 1, wherein In the microchannel layer (4), the number of detection channels is the same as the number of sample detection areas and sample outlets, specifically: The detection channels include a first detection channel (7), a second detection channel (8), a third detection channel (9), a fourth detection channel (10), a fifth detection channel (11), a sixth detection channel (12), and a seventh detection channel (13); The sample detection areas include a first sample detection area (15), a second sample detection area (16), a third sample detection area (17), a fourth sample detection area (18), a fifth sample detection area (19), a sixth sample detection area (20), and a seventh sample detection area (21); The sample outlets include a first sample outlet (23), a second sample outlet (24), a third sample outlet (25), a fourth sample outlet (26), a fifth sample outlet (27), a sixth sample outlet (28), and a seventh sample outlet (29); The specific connection relationship is as follows: The first detection channel (7) is connected to the first sample detection area (15), and the first sample liquid outlet (23) communicates with the outflow port of the first detection channel (7); the second detection channel (8) is connected to the second sample detection area (16), and the second sample liquid outlet (24) communicates with the outflow port of the second detection channel (8); the third detection channel (9) is connected to the third sample detection area (17), and the third sample liquid outlet (25) communicates with the outflow port of the third detection channel (9); the fourth detection channel (10) is connected to the fourth sample detection area (18), and the fourth sample liquid outlet (26) communicates with the outflow port of the fourth detection channel (10); the fifth detection channel (11) is connected to the fifth sample detection area (19), and the fifth sample liquid outlet (27) communicates with the outflow port of the fifth detection channel (11); the sixth detection channel (12) is connected to the sixth sample detection area (20), and the sixth sample liquid outlet (28) communicates with the outflow port of the sixth detection channel (12); the seventh detection channel (13) is connected to the seventh sample detection area (21), and the seventh sample liquid outlet (29) communicates with the outflow port of the seventh detection channel (13).

3. A portable high-throughput microparticle rapid detection device according to claim 1, characterized in that, The reference channel (6), the first detection channel (7), the second detection channel (8), the third detection channel (9), the fourth detection channel (10), the fifth detection channel (11), the sixth detection channel (12), the seventh detection channel (13), the reference sample detection liquid outlet (22), the first sample liquid outlet (23), the second sample liquid outlet (24), the third sample liquid outlet (25), the fourth sample liquid outlet (26), the fifth sample liquid outlet (27), the sixth sample liquid outlet (28) and the seventh sample liquid outlet (29) have the same width, all 80 μm, and are located on the same plane.

4. A portable high-throughput rapid micro-particle detection device according to claim 1, characterized in that, The reference detection area (14), the first sample detection area (15), the second sample detection area (16), the third sample detection area (17), the fourth sample detection area (18), the fifth sample detection area (19), the sixth sample detection area (20) and the seventh sample detection area (21) have the same specifications, with a length of 30 μm and a width of 15 μm, and the connection between the reference detection area (14) and the reference sample detection liquid outlet (22) is in a closed state.

5. A portable high-throughput microparticle rapid detection device according to claim 1, characterized in that, An angle (30) is provided between the reference channel (6), the first detection channel (7), the second detection channel (8), the third detection channel (9), the fourth detection channel (10), the fifth detection channel (11), the sixth detection channel (12) and the seventh detection channel (13), and the angle (30) is 45° for all.

6. The portable high-throughput microparticle rapid detection device according to claim 1, wherein, The width of the metal electrodes is 10 μm and the height is 200 nm for all.

7. A portable high-throughput microparticle rapid detection device according to claim 6, characterized in that, The metal electrodes are made of gold material and fabricated by physical vapor deposition process.

8. A portable high-throughput microparticle rapid detection device according to claim 1, characterized in that The PDMS cover layer (3) is made of PDMS material and fabricated by photolithography casting process.

9. A rapid microparticle detection method implemented by the portable high-throughput microparticle rapid detection device according to any one of claims 1-8, characterized in that, Including: S1. After cleaning the rice-shaped structure chip in the portable high-throughput microparticle rapid detection device, connect the signal processing system (31) in the portable high-throughput microparticle rapid detection device using the straight pin (32). S2. First, drop a certain amount of PBS buffer solution into the sample inlet (5), and then inject the sample to be detected into the sample inlet (5) using a syringe. S3. Connect the sample inlet (5), the reference sample detection outlet (22), each sample outlet and the signal processing system (31) with wires, turn on the power switch, and detect the sample to be detected. S4. The number of detected voltage pulse signals is equal to the number of particles, which are collected, analog-to-digital converted by the signal processing system and transmitted to the cloud for recording, and the detection data and the number of particles are displayed in real time through the small program on the mobile phone.

Images