A microfluidic detection chip

Abstract

The utility model relates to detection technical field and disclose a kind of microfluidic detection chip, comprising: substrate, substrate is composed of top layer function layer and bottom layer support layer, the outer surface of top layer function layer is formed continuous hydrophilic coating by plasma, its inner cavity center is provided with the microchannel of helical layout, upper surface center is provided with sample inlet, the liquid outlet end of sample inlet is connected with the liquid inlet end of microchannel, and detection area is arranged in the inner cavity lower part of top layer function layer, and is communicated with the liquid outlet end of microchannel, the inner cavity of detection area integrates three-dimensional electrode array, three-dimensional electrode array includes side wall electrode and bottom electrode, side wall electrode and bottom electrode are arranged in the inner wall both sides and bottom of detection area, drain hole is arranged in the upper surface of bottom layer support layer, and its liquid inlet end is connected with the liquid outlet end of detection area, three-dimensional electrode array forms three-dimensional space electric field, can collect electrochemical signal from multiple directions, improve detection sensitivity and accuracy.

Description

Technical Field

[0001] This utility model relates to the field of detection technology, specifically a microfluidic detection chip. Background Technology

[0002] Microfluidic detection chips are used in microfluidic technology and detection analysis. They are mainly used for the rapid detection of specific components in liquids. By integrating microchannels, detection areas and other structures on the chip, the transmission, processing and signal acquisition of the liquid to be detected can be realized. They have important application value in fields such as biomedicine and environmental monitoring.

[0003] In existing technologies, the electrodes used in the detection area of ​​microfluidic detection chips are mostly planar, which can only collect electrochemical signals from a single direction, making it difficult to comprehensively capture the signals of the components to be detected, thus limiting the sensitivity and accuracy of detection. At the same time, the microchannels are mostly designed as straight lines or simple bends, resulting in short flow paths and insufficient residence time for the liquid within the channels, preventing the components to be detected from being fully prepared and thus affecting subsequent detection results. Therefore, a microfluidic detection chip is proposed. Utility Model Content

[0004] To address the shortcomings of existing technologies, this invention provides a microfluidic detection chip that solves the technical problem that the electrodes used in the detection area are mostly planar, which can only collect electrochemical signals from the liquid to be detected from a single direction, making it difficult to comprehensively capture the signals of the components to be detected, thus limiting the detection sensitivity and accuracy.

[0005] To achieve the above objectives, this utility model provides the following technical solution: a microfluidic detection chip, comprising:

[0006] The substrate, and the top functional layer and the bottom support layer that make up the substrate, wherein the outer surface of the top functional layer is coated with a continuous hydrophilic coating by plasma, and a microchannel is provided in the center of the inner cavity of the top functional layer, and the microchannel is arranged in a spiral shape. An inlet is provided in the center of the upper surface of the top functional layer, and the liquid outlet of the inlet is connected to the liquid inlet of the microchannel.

[0007] The detection area is located in the lower part of the inner cavity of the top functional layer and is connected to the liquid outlet end of the microchannel. A three-dimensional electrode array is integrated in the inner cavity of the detection area, and the three-dimensional electrode array includes side wall electrodes and bottom surface electrodes. The side wall electrodes and bottom surface electrodes are disposed on both sides and the bottom of the inner wall of the detection area.

[0008] The drain hole is located on the upper surface of the bottom support layer, and the inlet end of the drain hole is connected to the outlet end of the detection area.

[0009] The top functional layer and the bottom support layer are fabricated separately. A spiral-shaped microchannel is fabricated in the center of the inner cavity of the top functional layer, and an inlet is fabricated in the center of the upper surface of the top functional layer, ensuring that the liquid outlet of the inlet is connected to the liquid inlet of the microchannel. A detection area is fabricated in the lower part of the inner cavity of the top functional layer, connecting the detection area to the liquid outlet of the microchannel. Sidewall electrodes and bottom electrodes are placed on both sides and the bottom of the inner wall of the detection area, forming a three-dimensional electrode array. Drainage holes are fabricated on the upper surface of the bottom support layer, ensuring that the liquid inlet of the drainage holes is connected to the liquid outlet of the detection area.

[0010] The outer surface of the top functional layer is subjected to plasma treatment to form a continuous hydrophilic coating;

[0011] The processed top functional layer and bottom support layer are assembled to form a complete substrate. At this point, all parts of the microfluidic detection chip are in the correct connection state and can realize its detection function.

[0012] Preferably, a flow guide groove is formed in the upper part of the inner cavity of the top functional layer, and the inlet and outlet ends of the flow guide groove are respectively connected to the outlet end of the sample inlet and the inlet end of the microchannel. After the liquid flows out from the outlet end of the sample inlet, it enters the inlet end of the flow guide groove. Then, guided by the flow guide groove, the liquid flows from its outlet end into the inlet end of the microchannel, completing the liquid transfer from the sample inlet to the microchannel.

[0013] Preferably, a diversion ridge is horizontally installed at the center of the inner cavity of the guide channel, and the guide channel is divided into two symmetrically distributed branches by the diversion ridge. When the liquid enters the guide channel, it will encounter the horizontally installed diversion ridge. Under the action of the diversion ridge, the liquid is divided into two symmetrically distributed branches and continues to flow in the guide channel.

[0014] Preferably, the distance between the spiral coils in the microchannel gradually decreases from top to bottom, and a connecting hole is provided between adjacent spiral coils in the microchannel. After the liquid enters the microchannel, it flows from top to bottom along the spiral-shaped channel. As the distance between the spiral coils gradually decreases, the constraint on the liquid during the flow gradually increases. At the same time, some liquid can flow and exchange between the channels of different spiral coils through the connecting hole between adjacent spiral coils.

[0015] Preferably, a guide hole is provided in the lower part of the inner cavity of the top functional layer, and the inlet and outlet ends of the guide hole are respectively connected to the outlet end of the detection area and the inlet end of the drain hole. The liquid after passing through the detection area flows out from the outlet end of the detection area, enters the inlet end of the guide hole, and then, guided by the guide hole, flows from its outlet end into the inlet end of the drain hole, and finally is discharged through the drain hole.

[0016] Preferably, the inner cavity of the guide hole is provided with a guide concave plate, and the upper surface of the guide concave plate is an arc-shaped design with a lower center and higher edges. When the liquid enters the guide hole, it will come into contact with the guide concave plate. Due to the arc-shaped design of the upper surface of the guide concave plate, the liquid will gather at the center of the guide concave plate under its own gravity and the guiding effect of the arc-shaped surface, and then continue to flow downward along the guide hole.

[0017] Compared with the prior art, this utility model provides a microfluidic detection chip with the following advantages:

[0018] This microfluidic detection chip integrates a three-dimensional electrode array in the detection area, including sidewall electrodes and bottom electrodes. The sidewall electrodes and bottom electrodes are respectively set on both sides of the inner wall and the bottom of the detection area, forming a three-dimensional spatial electric field. This allows for the acquisition of electrochemical signals from the liquid to be detected from multiple directions, improving the sensitivity and accuracy of detection and ensuring that the signals of the components to be detected can be captured more comprehensively.

[0019] The spiral-shaped microchannel layout increases the flow path and time of the liquid within the channel, allowing the components to be detected in the liquid to be fully prepared for subsequent detection. Attached Figure Description

[0020] Figure 1 This is a schematic diagram of the overall structure of this utility model;

[0021] Figure 2 This is a schematic diagram of the substrate separation structure of this utility model;

[0022] Figure 3 This is a schematic diagram of the flow guide channel and its connection structure of the present invention;

[0023] Figure 4 This is a schematic diagram of the microchannel and its connection structure of the present invention;

[0024] Figure 5 This is a schematic diagram of the flow guide concave plate and its connection structure of the present invention;

[0025] Figure 6 Appendix to this utility model Figure 5 Enlarged structural diagram at point A in the middle.

[0026] In the figure: 1. Substrate; 2. Top functional layer; 3. Bottom support layer; 4. Sample inlet; 5. Flow channel; 6. Flow splitter ridge; 7. Microchannel; 8. Connecting hole; 9. Detection area; 10. Three-dimensional electrode array; 11. Side wall electrode; 12. Bottom electrode; 13. Flow channel; 14. Flow channel concave plate; 15. Drain hole. Detailed Implementation

[0027] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the protection scope of the present utility model.

[0028] This utility model provides a technical solution, a microfluidic detection chip, including: (see details) Figure 1 , Figure 2 , Figure 3 , Figure 4 , Figure 5 and Figure 6 The substrate 1, the top functional layer 2 and the bottom support layer 3 that make up the substrate 1, and the outer surface of the top functional layer 2 is coated with a continuous hydrophilic coating by plasma, and a microchannel 7 is opened in the center of the inner cavity of the top functional layer 2. The microchannel 7 is arranged in a spiral shape, and an inlet 4 is opened in the center of the upper surface of the top functional layer 2. The liquid outlet of the inlet 4 is connected to the liquid inlet of the microchannel 7.

[0029] The detection area 9 is located in the lower part of the inner cavity of the top functional layer 2, and the detection area 9 is connected to the liquid outlet end of the microchannel 7. A three-dimensional electrode array 10 is integrated in the inner cavity of the detection area 9, and the three-dimensional electrode array 10 includes a side wall electrode 11 and a bottom electrode 12. The side wall electrode 11 and the bottom electrode 12 are disposed on both sides and the bottom of the inner wall of the detection area 9.

[0030] The drain hole 15 is located on the upper surface of the bottom support layer 3, and the inlet end of the drain hole 15 is connected to the outlet end of the detection area 9.

[0031] The top functional layer 2 and the bottom support layer 3 are processed separately. A spiral-shaped microchannel 7 is processed in the center of the inner cavity of the top functional layer 2, and an inlet 4 is processed in the center of the upper surface of the top functional layer 2 to ensure that the liquid outlet of the inlet 4 is connected to the liquid inlet of the microchannel 7. A detection area 9 is processed in the lower part of the inner cavity of the top functional layer 2 to connect the detection area 9 to the liquid outlet of the microchannel 7. At the same time, side wall electrodes 11 and bottom surface electrodes 12 are set on both sides and the bottom of the inner wall of the detection area 9 to form a three-dimensional electrode array 10. A drain hole 15 is processed on the upper surface of the bottom support layer 3 to ensure that the liquid inlet of the drain hole 15 can be connected to the liquid outlet of the detection area 9.

[0032] The outer surface of the top functional layer 2 is subjected to plasma treatment to form a continuous hydrophilic coating;

[0033] The processed top functional layer 2 and bottom support layer 3 are assembled to form a complete substrate 1. At this time, all parts of the microfluidic detection chip are in the correct connection state and can realize its detection function.

[0034] The substrate 1 consists of a top functional layer 2 and a bottom support layer 3. This layered structure design facilitates the processing of different functional areas separately, reduces the overall processing difficulty, and also facilitates later maintenance and replacement.

[0035] The outer surface of the top functional layer 2 is coated with a continuous hydrophilic coating through plasma. The hydrophilic coating can improve the fluidity of liquid on the surface of the top functional layer 2, which helps the sample liquid to enter the inlet 4 and the subsequent microchannel 7 more smoothly and reduce liquid residue.

[0036] The microchannel 7 has an overall spiral layout. Compared with other layouts such as straight lines, the spiral layout can increase the flow path length of the sample liquid in the microchannel 7 and prolong the residence time of the sample liquid in the microchannel 7, so that the sample liquid can be more fully pretreated or reacted, thereby improving the accuracy of detection.

[0037] The inner cavity of the detection area 9 integrates a three-dimensional electrode array 10, and the three-dimensional electrode array 10 includes side wall electrodes 11 and bottom surface electrodes 12 disposed on both sides and bottom of the inner wall of the detection area 9. This design of the three-dimensional electrode array 10 can detect the sample in the detection area 9 from multiple directions, increasing the contact area between the electrode and the sample and improving the sensitivity and stability of the detection.

[0038] The drainage hole 15 is designed to drain the liquid in the detection area 9 after the test is completed in a timely manner, so as to avoid the waste liquid remaining in the detection area 9 and affecting subsequent tests, thus ensuring the reliability of the test results.

[0039] Please see Figure 3 A flow guide trough 5 is provided in the upper part of the inner cavity of the top functional layer 2. The inlet and outlet ends of the flow guide trough 5 are connected to the outlet end of the sample inlet 4 and the inlet end of the microchannel 7, respectively. After the liquid flows out from the outlet end of the sample inlet 4, it enters the inlet end of the flow guide trough 5. Then, guided by the flow guide trough 5, the liquid flows from its outlet end into the inlet end of the microchannel 7, completing the transfer of liquid from the sample inlet 4 to the microchannel 7. The flow guide trough 5 can effectively guide the liquid flowing out from the sample inlet 4, so that the liquid can enter the microchannel 7 more smoothly, avoiding the liquid from stagnating or flowing poorly at the connection between the sample inlet 4 and the microchannel 7, and ensuring the continuity and stability of the liquid flow.

[0040] A diversion ridge 6 is horizontally installed at the center of the inner cavity of the flow guide trough 5, dividing the flow guide trough 5 into two symmetrically distributed branches. When liquid enters the flow guide trough 5, it encounters the horizontally installed diversion ridge 6. Under the action of the diversion ridge 6, the liquid is divided into two symmetrically distributed branches and continues to flow in the flow guide trough 5. The diversion ridge 6 divides the liquid into two symmetrical branches, which makes the distribution of liquid in the flow guide trough 5 more uniform, avoids the phenomenon of local liquid accumulation, and provides more balanced initial conditions for the subsequent flow and reaction processes after the liquid enters the microchannel 7.

[0041] Please see Figure 4 The distance between the spiral coils in the microchannel 7 gradually decreases from top to bottom, and a connecting hole 8 is provided between adjacent spiral coils in the microchannel 7. After the liquid enters the microchannel 7, it flows from top to bottom along the spiral-shaped channel. As the distance between the spiral coils gradually decreases, the constraint on the liquid during the flow gradually increases. At the same time, some liquid can flow and exchange between the channels of different spiral coils through the connecting hole 8 between adjacent spiral coils. The design of the spiral coils of the microchannel 7 gradually decreasing in distance can gradually adjust its flow state according to the needs of liquid flow, increase the contact opportunity and reaction time between the liquid and the channel wall, and the setting of the connecting hole 8 is conducive to the mixing and exchange of liquid between different spiral coil channels, improving the reaction efficiency or uniformity of the liquid in the microchannel 7.

[0042] A flow guide hole 13 is provided in the lower part of the inner cavity of the top functional layer 2. The inlet and outlet ends of the flow guide hole 13 are respectively connected to the outlet end of the detection zone 9 and the inlet end of the drain hole 15. After passing through the detection zone 9, the liquid flows out from the outlet end of the detection zone 9 and enters the inlet end of the flow guide hole 13. Then, guided by the flow guide hole 13, it flows from its outlet end into the inlet end of the drain hole 15 and is finally discharged through the drain hole 15. The flow guide hole 13 can provide a clear flow path for the liquid after detection, ensuring that the liquid can flow smoothly from the detection zone 9 into the drain hole 15, avoiding liquid residue in the area between the detection zone 9 and the drain hole 15, and ensuring the integrity and smoothness of the entire liquid processing process.

[0043] Please see Figure 6A flow guide plate 14 is provided inside the flow guide hole 13, and the upper surface of the flow guide plate 14 is an arc-shaped design with a lower center and higher edges. When liquid enters the flow guide hole 13, it will come into contact with the flow guide plate 14. Due to the arc-shaped design of the upper surface of the flow guide plate 14, the liquid will gather at the center of the flow guide plate 14 under its own gravity and the guiding effect of the arc surface, and then continue to flow downward along the flow guide hole 13. The arc-shaped flow guide plate 14 with a lower center and higher edges can play a good role in converging the liquid entering the flow guide hole 13, preventing the liquid from sticking to the inner wall of the flow guide hole 13, so that the liquid can flow downward more concentratedly, improve the flow efficiency of the liquid in the flow guide hole 13, and reduce liquid residue.

[0044] This scheme involves processing the top functional layer 2 and the bottom support layer 3 separately. The sample inlet 4 is processed at the center of the upper surface of the top functional layer 2, and the flow guide 5 is processed in the upper part of the inner cavity of the top functional layer 2. A diversion ridge 6 is installed laterally at the center of the inner cavity of the flow guide 5, so that the flow guide 5 is divided into two symmetrically distributed branches by the diversion ridge 6. At the same time, it is ensured that the liquid inlet end of the flow guide 5 is connected to the liquid outlet end of the sample inlet 4.

[0045] A spiral-shaped microchannel 7 is machined in the center of the inner cavity of the top functional layer 2, so that the distance between the spiral rings of the microchannel 7 gradually decreases from top to bottom, and a connecting hole 8 is machined between adjacent spiral rings of the microchannel 7, while ensuring that the liquid outlet end of the guide groove 5 is connected to the liquid inlet end of the microchannel 7.

[0046] A detection area 9 is processed in the lower part of the inner cavity of the top functional layer 2, so that the detection area 9 is connected to the liquid outlet end of the microchannel 7. At the same time, side wall electrodes 11 and bottom surface electrodes 12 are set on both sides and bottom of the inner wall of the detection area 9 to form a three-dimensional electrode array 10.

[0047] A flow guide hole 13 is machined in the lower part of the inner cavity of the top functional layer 2, and a flow guide concave plate 14 with an arc-shaped design of low center and high periphery is added to the inner cavity of the flow guide hole 13 to ensure that the liquid inlet end of the flow guide hole 13 is connected to the liquid outlet end of the detection area 9.

[0048] Drainage holes 15 are machined on the upper surface of the bottom support layer 3 to ensure that the inlet end of the drainage hole 15 is connected to the outlet end of the guide hole 13; the outer surface of the top functional layer 2 is subjected to plasma treatment to form a continuous hydrophilic coating.

[0049] The processed top functional layer 2 and bottom support layer 3 are assembled to form a complete substrate 1. At this time, all parts of the microfluidic detection chip are in the correct connection state and can realize its detection function.

[0050] It should be noted that, in this document, relational terms such as "first" and "second" are used only to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such process, method, article, or apparatus.

[0051] Although embodiments of the present invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the present invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. A microfluidic detection chip, characterized in that, include: The substrate (1), and the top functional layer (2) and the bottom support layer (3) that make up the substrate (1), and the outer surface of the top functional layer (2) is coated with a continuous hydrophilic coating by plasma, and a microchannel (7) is provided in the center of the inner cavity of the top functional layer (2), and the microchannel (7) is arranged in a spiral shape, and an inlet (4) is provided in the center of the upper surface of the top functional layer (2), and the liquid outlet of the inlet (4) is connected to the liquid inlet of the microchannel (7); The detection area (9) is located in the lower part of the inner cavity of the top functional layer (2), and the detection area (9) is connected to the liquid outlet end of the microchannel (7). A three-dimensional electrode array (10) is integrated in the inner cavity of the detection area (9), and the three-dimensional electrode array (10) includes a side wall electrode (11) and a bottom electrode (12). The side wall electrode (11) and the bottom electrode (12) are disposed on both sides and the bottom of the inner wall of the detection area (9). A drain hole (15) is provided on the upper surface of the bottom support layer (3), and the inlet end of the drain hole (15) is connected to the outlet end of the detection area (9).

2. The microfluidic detection chip according to claim 1, characterized in that: The upper part of the inner cavity of the top functional layer (2) is provided with a flow guide groove (5), and the liquid inlet and liquid outlet of the flow guide groove (5) are respectively connected to the liquid outlet of the sample inlet (4) and the liquid inlet of the microchannel (7).

3. A microfluidic detection chip according to claim 2, characterized in that: The inner center of the guide channel (5) is horizontally installed with a diversion ridge (6), and the guide channel (5) is divided into two symmetrically distributed branches by the diversion ridge (6).

4. A microfluidic detection chip according to claim 1, characterized in that: The distance between the spiral coils in the microchannel (7) gradually decreases from top to bottom, and a connecting hole (8) is provided between adjacent spiral coils in the microchannel (7).

5. A microfluidic detection chip according to claim 1, characterized in that: The lower part of the inner cavity of the top functional layer (2) is provided with a guide hole (13), and the liquid inlet and liquid outlet of the guide hole (13) are respectively connected to the liquid outlet of the detection area (9) and the liquid inlet of the drain hole (15).

6. A microfluidic detection chip according to claim 5, characterized in that: The inner cavity of the guide hole (13) is provided with a guide concave plate (14), and the upper surface of the guide concave plate (14) is an arc-shaped design with a low center and a high periphery.

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