A microfluidic chip, detection system and detection method

Abstract

The application provides a micro-fluidic chip, a detection system and a detection method, and belongs to the technical field of microorganism detection. The micro-fluidic chip comprises a substrate, and a sample inlet channel, a pretreatment module, a focusing module, a separation module and an enrichment cavity are sequentially arranged in the substrate. The pretreatment module is composed of multiple continuous U-shaped channels. The focusing module comprises a main air duct connected with the U-shaped channels and branch air ducts symmetrically connected to the two sides of the main air duct. The separation module comprises a cavity, the inlet direction and the outlet direction of the cavity are arranged at an angle, one side wall of the cavity is a superior arc, and the other side wall is an inferior arc. The enrichment cavity is connected with the outlet of the cavity. An air outlet channel is arranged at the outlet of the cavity and communicates with the outside of the substrate. Through the innovative modular design, the problems of low microorganism detection efficiency and complex operation in the prior art are solved.

Description

Technical Field

[0001] This invention relates to the field of microbial detection technology, and in particular to a microfluidic chip, detection system, and detection method. Background Technology

[0002] With the acceleration of industrialization and urbanization, the problem of airborne microbial pollution has become increasingly prominent. Especially in environments with high humidity and poor ventilation, microorganisms such as fungal spores can proliferate in large numbers, posing potential risks to machinery, public health, and crops. Traditional methods of microbial detection mainly rely on laboratory culture and microscopic observation. While these methods can provide diagnostic data, they suffer from drawbacks such as low efficiency, complex operation, and high subjectivity of results, and often require several days to obtain preliminary results.

[0003] Among related technologies, microfluidics, as an emerging biodetection technology, has shown great potential in the field of microbial detection. Microfluidic chip technology can achieve efficient sample separation, enrichment, and detection at a tiny scale.

[0004] However, the application of existing microfluidic technology in microbial detection still has some shortcomings. For example, in airborne microbial detection, problems such as how to efficiently remove impurities from samples, accurately focus on target microorganisms, and rapidly separate spores of different sizes have not been fully solved. Existing microfluidic chips often require the specific design of structures such as channels, chambers, and microvalves, which makes control during detection experiments cumbersome and significantly increases detection costs, contradicting the original intention of convenient and efficient detection. Summary of the Invention

[0005] This invention provides a microfluidic chip, a detection system, and a detection method. Through innovative modular design, it solves the problems of low efficiency and complex operation in existing microbial detection technologies. The technical solution is as follows:

[0006] In a first aspect, embodiments of the present invention provide a microfluidic chip, comprising: a substrate,

[0007] The substrate is provided with a sample inlet channel, a pretreatment module, a focusing module, a separation module, and an enrichment chamber connected in sequence. The pretreatment module consists of multiple continuously rotating U-shaped channels. The focusing module includes a main gas channel connected to the U-shaped channels and branch gas channels symmetrically connected to both sides of the main gas channel. The separation module includes a cavity with its inlet and outlet directions arranged at an angle. One side wall of the cavity is a superior arc shape, and the other side wall is a inferior arc shape. The enrichment chamber is connected to the outlet of the cavity. An outlet channel connecting to the outside of the substrate is also provided at the outlet of the cavity.

[0008] Optionally, the branch airway is arranged at an acute angle to the main airway and its inlet faces the sample inlet channel.

[0009] Optionally, the width of the inlet end of the cavity is narrower than the width of the main airway.

[0010] Optionally, a separation channel is provided between the outlet of the cavity and the enrichment cavity, and the gas outlet channel is connected to the separation channel.

[0011] Optionally, the substrate is a polydimethylsiloxane structural component.

[0012] Secondly, embodiments of the present invention provide a detection system, including the microfluidic chip described in the first aspect, and further including a microscopic module, an air inlet pump and two micro air pumps. The image acquisition end of the microscopic module is connected to the enrichment cavity, the air inlet pump is connected to the inlet of the sample injection channel, and the two micro air pumps are respectively connected to the inlets of the two branch channels.

[0013] Optionally, the miniature air pump is connected to the inlet of the bronchus via a capillary tube or a flexible tube.

[0014] Thirdly, embodiments of the present invention provide a detection method, implemented based on the detection system described in the second aspect above, comprising:

[0015] Step 1: Power is provided by the air intake pump, and air containing microbial spores is introduced into the detection system through the sample introduction channel;

[0016] Step 2: In the pretreatment module, large particulate impurities are separated and the microbial spores are settled through multiple continuously rotating U-shaped channels;

[0017] Step 3: Inert gas is introduced into the two bronchial channels at the same intake rate using two micro air pumps to focus and align the microbial spores in the mixed gas passing through the main air channel;

[0018] Step 4: In the separation module, the microbial spores of different sizes are separated by the optimal arc circle design of the cavity, so that the desired microbial spores enter the enrichment cavity and the gas is discharged through the gas outlet channel;

[0019] Step 5: Use a microscope module to acquire images of the microbial spores collected in the enrichment chamber and transmit the data to a computer terminal for display, identification and storage.

[0020] The beneficial effects of the technical solutions provided in the embodiments of the present invention include at least the following:

[0021] The microfluidic chip provided in this invention employs an innovative modular design to perform multi-stage processing on the introduced mixed gas containing microbial spores. First, a continuously rotating U-shaped channel in the pretreatment module separates large particulate impurities and allows microbial spores to settle. Then, in the focusing module, gas is introduced through a bypass bronchus to focus and align the microbial spores in the mixed gas. In the separation module, a cavity with a superior arc design further filters the microbial spores to be detected. Finally, the enrichment cavity collects the microbial spores to be detected for identification and detection. Its simple interval design eliminates the need for complex auxiliary controls, effectively solving the problems of low efficiency and complex operation in existing microbial detection technologies. It is suitable for fields such as environmental monitoring, public health, and food safety. Attached Figure Description

[0022] To more clearly illustrate the technical solutions in the embodiments of the present invention, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0023] Figure 1 This is a schematic diagram of the internal structure of the microfluidic chip provided in an embodiment of the present invention;

[0024] Figure 2 This is a schematic diagram of the detection system provided in an embodiment of the present invention;

[0025] Figure 3 This is a flowchart of the detection method provided in the embodiments of the present invention.

[0026] In the figure: 1-substrate; 2-microscopic module; 3-inlet pump; 4-micro pump; 11-sample inlet channel; 12-pretreatment module; 13-focusing module; 14-separation module; 15-enrichment chamber; 16-outlet channel; 17-separation channel; 131-main air channel; 132-branch air channel. Detailed Implementation

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

[0028] Figure 1 This is a schematic diagram of the internal structure of the microfluidic chip provided in an embodiment of the present invention; Figure 2 This is a schematic diagram of the detection system provided in an embodiment of the present invention. Figures 1 to 2 As shown, an embodiment of the present invention provides a microfluidic chip, including a substrate 1.

[0029] The substrate 1 contains a sample inlet channel 11, a pretreatment module 12, a focusing module 13, a separation module 14, and an enrichment chamber 15, which are connected in sequence. The pretreatment module 12 consists of multiple continuously rotating U-shaped channels. The focusing module 13 includes a main air channel 131 connected to the U-shaped channels and branch air channels 132 symmetrically connected to both sides of the main air channel 131. The separation module 14 includes a cavity with its inlet and outlet directions arranged at an angle. One side wall of the cavity is of a superior arc shape, and the other side wall is of a inferior arc shape. The enrichment chamber 15 is connected to the outlet of the cavity, and an outlet channel 16 connecting to the outside of the substrate 1 is also provided at the outlet of the cavity.

[0030] In this embodiment of the invention, the substrate 1 is placed in an environment containing microbial spores during the testing process. A power component, such as an air pump, is installed outside the sample inlet channel 11 to introduce gas containing microbial spores from the environment into the microfluidic chip. The mixed gas first undergoes preliminary treatment in the pretreatment module 12. During the flow within multiple U-shaped channels, some larger impurities in the mixed gas will remain and fall off after impacting the sidewalls of the U-shaped channels, resulting in the initial separation of large particles. Simultaneously, the continuously rotating channel structure causes the microbial spores in the mixed gas to settle under their own gravity, allowing the air containing microbial spores to be transported to the main air duct 131 of the focusing module 13. During the flow through the main air duct 131, external airflow is introduced through the branch air ducts 132 on both sides, causing the microbial spores in the mixed gas in the main air duct 131 to focus from a chaotic distribution and arrange into a line along the extension direction of the main air duct 131, facilitating subsequent separation and enrichment. After the rearranged mixed gas enters the cavity of the separation module 14, as it flows towards the cavity outlet, it preferentially passes through the opposing side walls, which are shaped like a superior arc and a inferior arc, due to the angular offset arrangement of the inlet and outlet. The cavity, designed with superior arc circles on its opposing side walls, utilizes the flow characteristics of fluid in a curved channel. By adjusting the curvature, width, and flow velocity, microbial spores of different sizes or masses are separated during fluid flow. Larger spores experience greater inertial forces during flow, thus deflecting towards the superior arc side wall and separating from the smaller spores to be detected along their flow trajectory. This allows the microbial spores to be detected to exit the cavity outlet from the side that is relatively aligned with the inferior arc side wall. Ultimately, the gas with excessively high flow rate is discharged through the gas outlet channel 16 due to pressure, while the microbial spores to be detected enter the enrichment chamber 15. The collected target microbial spores can be imaged and analyzed using relevant microscopic observation equipment, and the processed data is transmitted to the computer terminal to complete the entire display, identification and storage process.

[0031] The microfluidic chip provided in this invention employs an innovative modular design to perform multi-stage processing on the introduced mixed gas containing microbial spores. First, large particulate impurities and microbial spores are separated and settled through a continuously rotating U-shaped channel in the pretreatment module 12. Then, in the focusing module 13, gas is introduced through a bypass channel 132 to focus and align the microbial spores in the mixed gas. In the separation module 14, a cavity with a superior arc-shaped design further filters the microbial spores to be detected. Finally, the enrichment cavity 15 collects the microbial spores to be detected for identification and detection. Its simple interval design eliminates the need for complex auxiliary controls, effectively solving the problems of low efficiency and complex operation in existing microbial detection technologies. It is suitable for fields such as environmental monitoring, public health, and food safety.

[0032] Optionally, the branch channels 132 are arranged at an acute angle to the main channel 131, with their inlets facing the sample inlet channel 11. Exemplarily, in this embodiment of the invention, the inlet ends of the two branch channels 132 face one side of the sample inlet channel 11 and are arranged at an acute angle to the main channel 131, ranging from 10° to 50°. The gas introduced by the two branch channels 132 enters the main channel 131 with the same intake volume. Utilizing its airflow symmetry and vortex effect, the microbial spores in the mixed gas are subjected to a more uniform airflow force, thereby guiding the microbial spores to the core position of the airflow. This further helps to focus scattered microbial spores into a line, reducing chaotic movement in the airflow.

[0033] Optionally, the width of the inlet end of the cavity is narrower than the width of the main airway 131. For example, in this embodiment of the invention, by setting the width of the inlet end of the cavity, i.e., the width of the end of the main airway 131, relatively narrower, the airflow velocity at the inlet end of the cavity can be increased by utilizing the contraction effect, thereby generating greater kinetic energy. This helps to push the microbial spores in a more concentrated direction, further promoting the alignment of the flow direction of the microbial spores in the airflow entering the cavity, which is beneficial for subsequent inertial separation.

[0034] Optionally, a separation channel 17 is provided between the outlet of the cavity and the enrichment cavity 15, and an exhaust channel 16 is connected to the separation channel 17. Exemplarily, in this embodiment of the invention, the mixed gas containing microbial spores discharged from the outlet of the cavity typically has a high inertial force. Most of the microbial spore particles contained in the airflow will have their trajectory altered by the airflow. By providing an exhaust channel 16 on the separation channel 17 connected to the enrichment cavity 15, the faster-flowing gas in the mixed gas after separation and screening by the cavity will be discharged through the exhaust channel 16 due to the local pressure reduction, while the microbial spores, due to their lower inertia, can continue to flow into the enrichment cavity 15 through the separation channel 17 for collection. This arrangement removes excess fast-flowing gas from the mixed gas, improving the enrichment efficiency of microbial spores, while also avoiding interference from the airflow on the enriched microbial spores, which is beneficial for subsequent analysis and detection.

[0035] Optionally, substrate 1 is a polydimethylsiloxane (PDS) structural component. Exemplarily, in this embodiment of the invention, substrate 1 is made of PDS, a highly biocompatible material that is non-toxic to biological cells and microorganisms. Therefore, it is suitable for use in microbial detection, cell culture, and biological sample analysis, ensuring that it does not interfere with the characteristics of the sample itself or affect the detection results. It has relatively low processing difficulty and can be manufactured with high precision using common soft lithography techniques (such as microlithography, mold replication, etc.). It can easily form tiny channel structures, making it suitable for manufacturing microchannels in microfluidic chips and improving detection accuracy.

[0036] refer to Figure 2 This invention also provides a detection system, including a microfluidic chip as shown in the figure. The system further includes a microscope module 2, an air inlet pump 3, and two miniature air pumps 4. The image acquisition end of the microscope module 2 is connected to the enrichment cavity 15, the air inlet pump 3 is connected to the inlet of the sample injection channel 11, and the two miniature air pumps 4 are respectively connected to the inlets of two branch air channels 132. Exemplarily, in this embodiment of the invention, the airflow power supply to the microfluidic chip is achieved through the external air inlet pump 3 and the two miniature air pumps 4. The microscope module 2, which consists of a dedicated optical fiber microscope system, a light source and illumination system, and image processing and analysis software, is used to detect, analyze, and provide signal feedback for the microbial spores collected in the enrichment cavity 15.

[0037] Optionally, the miniature air pump 4 is connected to the inlet of the bronchus 132 via a capillary tube or a flexible tube. When supplying air to the bronchus 132, a capillary tube is used. Due to its small inner diameter, the capillary effect provides a relatively stable and controllable fluid flow rate. The small size and high precision of the capillary tube make it suitable for use with microfluidic chips, enabling precise control of gas input and flow rate. The air pump draws in spore-containing gas through the capillary tube, which helps to smooth the gas flow in the microfluidic chip and reduce flow fluctuations. For sections requiring larger gas flow rates, flexible tubes offer more options, especially when connecting a larger air pump to a sample introduction module. The flexible tube's channel can accommodate more airflow, helping to improve flow transmission efficiency and reduce flow limitation issues. This embodiment of the invention does not limit the specific connection method between the miniature air pump 4 and the bronchus 132.

[0038] Figure 3 This is a flowchart of the detection method provided in an embodiment of the present invention. Figure 3 As shown, embodiments of the present invention also provide a detection method based on Figure 2 The detection system shown is characterized by comprising:

[0039] S1. Power is provided by the air intake pump 3, and air containing microbial spores is introduced into the detection system through the sample introduction channel 11.

[0040] S2. In the pretreatment module 12, large particulate impurities are separated and microbial spores are settled through multiple continuously rotating U-shaped channels.

[0041] S3. Inert gas is introduced into the two branch channels 132 with the same intake volume through two micro air pumps 4, so as to focus and arrange the microbial spores in the mixed gas passing through the main air channel 131.

[0042] S4. In the separation module 14, the cavity's superior arc circle design is used to separate microbial spores of different sizes, so that the required microbial spores enter the enrichment cavity 15, and the gas is discharged through the gas outlet channel 16.

[0043] S5. Use the microscopic module 2 to acquire images of the microbial spores collected in the enrichment chamber 15 and transmit the data to the computer terminal for display, recognition and storage.

[0044] The detection system, composed of the microfluidic chip provided in this embodiment of the invention, utilizes the aforementioned detection method for gaseous microbial detection. Through an innovative modular design, it performs multi-stage processing on the introduced mixed gas containing microbial spores. First, large particulate impurities and microbial spores are separated and settled via a continuously rotating U-shaped channel in the pretreatment module 12. Then, in the focusing module 13, gas is introduced through a bypass channel 132 to focus and arrange the microbial spores in the mixed gas. In the separation module 14, a cavity with a superior arc-shaped design further filters the microbial spores to be detected. Finally, the enrichment cavity 15 collects the microbial spores to be detected for identification and detection. Its simple structural design eliminates the need for complex auxiliary controls, effectively solving the problems of low efficiency and complex operation in existing microbial detection technologies. It is suitable for fields such as environmental monitoring, public health, and food safety.

[0045] The technical features of the above embodiments can be combined arbitrarily. For the sake of brevity, not all possible combinations of the technical features in the above embodiments are described; only preferred embodiments of the present invention are illustrated. The descriptions are relatively specific and detailed, but they should not be construed as limiting the scope of the present invention. As long as the combination of these technical features does not contradict each other, it should be considered within the scope of this specification.

[0046] It should be noted that those skilled in the art can make various modifications and improvements without departing from the inventive concept, and these all fall within the scope of protection of this invention. Therefore, the scope of protection of this invention should be determined by the appended claims.

Claims

1. A microfluidic chip, characterized in that, include: base plate (1), The substrate (1) is provided with a sample inlet channel (11), a pretreatment module (12), a focusing module (13), a separation module (14), and an enrichment chamber (15) connected in sequence. The pretreatment module (12) is composed of multiple continuously rotating U-shaped channels. The focusing module (13) includes a main air channel (131) connected to the U-shaped channel and branch air channels (132) symmetrically connected to both sides of the main air channel (131). The separation module (14) includes a cavity with the inlet and outlet directions of the cavity arranged at an angle. One side wall of the cavity is a superior arc shape, and the other side wall is a inferior arc shape. The enrichment chamber (15) is connected to the outlet of the cavity. An outlet channel (16) connecting the outside of the substrate (1) is also provided at the outlet of the cavity.

2. A microfluidic chip according to claim 1, characterized in that, The bronchial airway (132) is arranged at an acute angle to the main airway (131) and its inlet faces the sample inlet channel (11).

3. A microfluidic chip according to claim 1, characterized in that, The width of the inlet end of the cavity is narrower than the width of the main airway (131).

4. A microfluidic chip according to claim 1, characterized in that, A separation channel (17) is provided between the outlet of the cavity and the enrichment cavity (15), and the air outlet channel (16) is connected to the separation channel (17).

5. A microfluidic chip according to claim 1, characterized in that, The substrate (1) is a polydimethylsiloxane structural component.

6. A detection system comprising a microfluidic chip as described in any one of claims 1 to 5, characterized in that, It also includes a microscopic module (2), an air inlet pump (3) and two micro air pumps (4). The image acquisition end of the microscopic module (2) is connected to the enrichment cavity (15), the air inlet pump (3) is connected to the inlet of the sample inlet channel (11), and the two micro air pumps (4) are respectively connected to the inlets of the two branch channels (132).

7. The detection system according to claim 6, characterized in that, The micro air pump (4) is connected to the inlet of the bronchus (132) via a capillary tube or a flexible tube.

8. A detection method, implemented based on the detection system as described in claim 6, characterized in that, include: Step 1: Power is provided by the air pump (3), and air containing microbial spores is introduced into the detection system through the sample introduction channel (11); Step 2: In the pretreatment module (12), large particulate impurities are separated and the microbial spores are settled by multiple continuously rotating U-shaped channels; Step 3: Inert gas is introduced into the two branch channels (132) at the same intake volume through two micro air pumps (4) to focus and align the microbial spores in the mixed gas passing through the main air channel (131); Step 4: In the separation module (14), the microbial spores of different sizes are separated by the optimal arc circle design of the cavity, so that the desired microbial spores enter the enrichment cavity (15) and the gas is discharged through the gas outlet channel (16); Step 5: Use the microscopic module (2) to acquire images of the microbial spores collected in the enrichment chamber (15) and transmit the data to a computer terminal for display, recognition and storage.

Images