Microfluidic system and microfluidic sorting method

Abstract

The invention provides a microfluidic system and a microfluidic sorting method.The microfluidic system comprises a fluorescence sorting module, the fluorescence sorting module comprises a fluorescence intensity detection unit, a control unit and a microfluidic fluorescence sorting unit, the fluorescence intensity detection unit is used for detecting the fluorescence intensity of a magnetic nano microbial sensor sample flowing through a microchannel, and the control unit is used for controlling the fluorescence intensity of the magnetic nano microbial sensor sample flowing through the microchannel; the control unit is used for controlling the micro-fluidic fluorescence sorting unit to sort out the strong-fluorescence magnetic nano microbial sensor; the magnetic separation module comprises a uniform magnetic field established by a coil and a microfluidic magnetic separation unit, and the uniform magnetic field established by the coil is used for separating the strongly fluorescent magnetic nano microbial sensor with uniform magnetic distribution and then transmitting the separated strongly fluorescent magnetic nano microbial sensor to the microfluidic magnetic separation unit; the micro-fluidic magnetic separation unit is used for separating the strongly fluorescent magnetic nano microbial sensor with uniformly distributed magnetic force to an output channel with a corresponding magnetic force range, and according to the technical scheme of the embodiment of the invention, the separation precision and efficiency can be improved.

Description

Technical Field

[0001] The present invention relates to the field of microfluidic technology, and in particular to a microfluidic system and a microfluidic sorting method. Background Art

[0002] Microfluidics, with its advantages of high sensitivity, high throughput, and low sample consumption, has become an important analytical tool in fields such as biomedical testing, environmental monitoring, and materials science. However, existing microfluidic sorting systems, particularly those based on magnetic nanomicrobial sensors, still suffer from poor sorting performance, limiting their widespread adoption in practical applications. Summary of the Invention

[0003] The purpose of the present invention is to solve at least one of the technical problems existing in the prior art and to provide a microfluidic system and a microfluidic sorting method, which are conducive to improving sorting accuracy and efficiency.

[0004] In a first aspect, an embodiment of the present invention provides a microfluidic system, comprising:

[0005] The fluorescence sorting module includes a fluorescence intensity detection unit, a control unit, and a microfluidic fluorescence sorting unit. The fluorescence intensity detection unit is used to detect the fluorescence intensity of the magnetic nanomicroorganism sensor sample flowing through the microchannel. The control unit is used to control the microfluidic fluorescence sorting unit to sort out the strong fluorescent magnetic nanomicroorganism sensor.

[0006] The magnetic sorting module includes a uniform magnetic field established by a coil and a microfluidic magnetic sorting unit. The uniform magnetic field established by the coil is used to sort the strong fluorescent magnetic nanomicroorganism sensor with uniform magnetic force distribution and then transmit it to the microfluidic magnetic sorting unit. The microfluidic magnetic sorting unit is used to sort the strong fluorescent and uniform magnetic nanomicroorganism sensor to the output channel corresponding to the magnetic force size range.

[0007] The microfluidic system provided by an embodiment of the present invention has at least the following beneficial effects: by constructing a dual-sorting microfluidic system comprising a fluorescence sorting module and a magnetic sorting module, and combining fluorescence sorting and magnetic sorting technologies, a dual screening of magnetic nanomicrobial sensor samples is achieved. Fluorescence sorting is used as a preliminary screening method to quickly identify and separate strong fluorescent magnetic nanomicrobial sensors with strong fluorescence signals. The magnetic sorting module then further sorts strong fluorescent magnetic nanomicrobial sensors with uniform magnetic distribution based on magnetic distribution characteristics. The strong fluorescent and uniform magnetic distribution sensors are then sorted into output channels corresponding to magnetic ranges based on magnetic magnitude characteristics, thereby sorting strong fluorescent magnetic nanomicrobial sensors of different magnetic magnitudes into target sensor groups corresponding to magnetic ranges, ensuring that the magnetic distribution of sensors within the corresponding target sensor group is uniform and consistent. The dual sorting mechanism of this embodiment significantly improves the sorting accuracy and enhances the versatility and flexibility of the microfluidic system. It can solve the problems of poor reproducibility and low stability of sensors sorted by traditional sorting methods during application, and is conducive to improving the accuracy and efficiency of subsequent sensor detection. It has broad application prospects in various detection fields.

[0008] In the above-mentioned microfluidic system, the fluorescence sorting module also includes a fluorescence spectrum acquisition and imaging unit, which is used to collect and analyze the fluorescence signal spontaneously generated by the magnetic nanomicroorganism sensor sample and transmit it to the control unit. The fluorescence intensity detection unit also includes an avalanche photoelectric detection circuit, which is used to convert the fluorescence signal into an electrical signal after detecting it and send a pulse signal to the control unit.

[0009] In this embodiment, the fluorescence spectrum acquisition and imaging unit can simultaneously acquire both the spectral and spatial distribution information of the fluorescence signal, which is then transmitted to the control unit for further analysis. Furthermore, the fluorescence signal spontaneously generated by the magnetic nanomicrobial sensor sample is detected by an avalanche photodetection circuit. Upon detecting a strong fluorescence signal, the avalanche photodetection circuit converts it into an electrical signal and sends a pulse signal to the control unit. The control unit, combined with the fluorescence data analyzed by the fluorescence spectrum acquisition and imaging unit, can issue a sorting control signal to control the microfluidic fluorescence sorting unit to select highly fluorescent magnetic nanomicrobial sensors. Combining the fluorescence spectrum acquisition and imaging unit with a fluorescence intensity detection unit can improve detection accuracy and resolution.

[0010] In the above microfluidic system, the fluorescence sorting module further includes a first sample channel and a first waste liquid channel, and the control unit is further configured to:

[0011] When the intensity of the fluorescent signal is greater than or equal to a preset intensity threshold, the first sample channel is controlled to open so that the strong fluorescent magnetic nano-microorganism sensor enters the first sample channel; or

[0012] When the intensity of the fluorescent signal is less than a preset intensity threshold, the first waste liquid channel is controlled to be open, so that the weak fluorescent magnetic nano-microorganism sensor enters the first waste liquid channel.

[0013] In the above microfluidic system, the fluorescence sorting module further comprises a sample sorting unit, and the sample sorting unit is used to control the flow of the magnetic nano-microorganism sensor sample to be deflected to a corresponding channel.

[0014] In the above microfluidic system, the uniform magnetic field established by the coil is used to utilize the coupling effect of magnetic field force, flow force and gravity to sort the strong fluorescent magnetic nanomicroorganism sensors based on whether the magnetic force is uniformly distributed.

[0015] In the above microfluidic system, the magnetic sorting module further comprises a transmitter, which is used to transmit the sorted magnetic nano-microorganism sensor with strong fluorescence and uniform magnetic distribution to the microfluidic magnetic sorting unit.

[0016] In the above-mentioned microfluidic system, the microfluidic magnetic sorting unit includes a bifurcated pipe structure and a magnet. The microfluidic magnetic sorting unit is used to adjust the flow rate and magnetic field force in the bifurcated pipe structure, control the deflection of strong fluorescence and magnetic nano-microorganism sensors with uniform magnetic force distribution of different magnetic force magnitudes, and sort them to output channels corresponding to the magnetic force magnitude range.

[0017] In the above microfluidic system, the minimum distance between the magnet and the bifurcated pipe structure is within a preset distance range.

[0018] The above microfluidic system further includes a magnetic characterization module, which is used to characterize the magnetic nano-microorganism sensor with strong fluorescence and uniform magnetic distribution after sorting by the microfluidic magnetic sorting unit.

[0019] In a second aspect, an embodiment of the present invention provides a microfluidic sorting method based on the microfluidic system of the first aspect, comprising:

[0020] The prepared magnetic nanomicrobial sensor sample is injected into the microchannel of the microfluidic chip;

[0021] The strong fluorescent magnetic nanomicroorganism sensors are magnetically sorted by the magnetic sorting module, and the strong fluorescent magnetic nanomicroorganism sensors with uniform magnetic distribution are sorted out by the uniform magnetic field generated by the coil. Then, the strong fluorescent magnetic nanomicroorganism sensors with uniform magnetic distribution and different magnetic strengths are sorted into the target sensor group corresponding to the magnetic strength range.

[0022] According to the microfluidic sorting method provided in an embodiment of the present invention, a dual screening of magnetic nanomicrobial sensor samples is achieved by combining fluorescence sorting and magnetic sorting technology. Fluorescence sorting is used as a means of preliminary screening to quickly identify and separate strong fluorescent magnetic nanomicrobial sensors with strong fluorescence signals. Then, after sorting out strong fluorescent magnetic nanomicrobial sensors with uniform magnetic distribution according to the magnetic distribution characteristics, the strong fluorescent and uniform magnetic distribution sensors are sorted into output channels corresponding to the magnetic magnitude range according to the magnetic magnitude characteristics, thereby achieving the goal of sorting strong fluorescent magnetic nanomicrobial sensors of different magnetic magnitudes into target sensor groups corresponding to the magnetic magnitude range, ensuring that the magnetic distribution of sensors in the corresponding target sensor group is uniform and consistent in magnitude. The dual sorting mechanism of this embodiment significantly improves the accuracy of sorting, can solve the problems of poor reproducibility and low stability of sensors sorted by traditional sorting methods during application, is conducive to improving the accuracy and efficiency of subsequent sensor detection, and has broad application prospects in various detection fields.

[0023] Other features and advantages of the present invention will be described in the following description, and in part will become apparent from the description, or will be understood by practicing the present invention. The purpose and other advantages of the present invention can be realized and obtained through the structures particularly pointed out in the description and the drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] The present invention will be further described below with reference to the accompanying drawings and embodiments;

[0025] Figure 1 Schematic diagram of the structure of a microfluidic system provided by an embodiment of the present invention;

[0026] Figure 2 1 is a schematic structural diagram of a fluorescence sorting module provided by an embodiment of the present invention;

[0027] Figure 3 It is a structural schematic diagram of a magnetic separation module provided by an embodiment of the present invention. DETAILED DESCRIPTION

[0028] This section will describe in detail the specific embodiments of the present invention. The preferred embodiments of the present invention are shown in the accompanying drawings. The purpose of the accompanying drawings is to supplement the description of the text part of the specification with graphics, so that people can intuitively and vividly understand each technical feature and the overall technical solution of the present invention, but it should not be understood as a limitation on the scope of protection of the present invention.

[0029] It should be understood that in the description of the embodiments of the present invention, if there is a description of "first", "second", etc., it is only for the purpose of distinguishing technical features, and cannot be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features or implicitly indicating the order of the indicated technical features. "At least one" means one or more, "more" means more than two, greater than, less than, exceed, etc. are understood to exclude the number itself, above, below, within, etc. are understood to include the number itself, and "several" means one or more, unless otherwise clearly and specifically defined. "And / or" describes the association relationship of associated objects, indicating that three relationships can exist. It can be understood that A and / or B can mean the existence of A alone, the existence of A and B at the same time, or the existence of B alone. A and B can be singular or plural.

[0030] In addition, unless otherwise clearly specified and limited, the term "connection / connected" should be understood in a broad sense. For example, it can be a fixed connection or a movable connection, a detachable connection or a non-detachable connection, or an integral connection; it can be a mechanical connection, an electrical connection, or can communicate with each other; it can be directly connected or indirectly connected through an intermediate medium. It should be noted that although the logical order is shown in the flowchart, in some cases, the steps shown or described can be performed in an order different from that in the flowchart. It should be noted that the technical features involved in the various embodiments of the present invention described below can be combined with each other as long as they do not conflict with each other.

[0031] The embodiments of the present invention are further described below with reference to the accompanying drawings.

[0032] Microfluidics, with its advantages of high sensitivity, high throughput, and low sample consumption, has become an important analytical tool in fields such as biomedical testing, environmental monitoring, and materials science. However, existing microfluidic sorting systems, particularly those based on magnetic nanomicrobial sensors, still suffer from poor sorting performance, limiting their widespread adoption in practical applications.

[0033] Specifically, poor sorting performance of magnetic nanomicrobial sensors can lead to poor stability and reproducibility in specific applications, making it difficult to meet the high-precision, high-throughput, and high-stability requirements of modern detection. Therefore, developing a novel microfluidic system that can effectively address these issues is of great practical significance and has broad application prospects.

[0034] Based on the above problems, Figures 1 to 3 As shown, Figure 1 A schematic structural diagram of a microfluidic system provided in an embodiment of the present invention is shown in FIG. Figure 2 A schematic structural diagram of a fluorescence sorting module provided in an embodiment of the present invention is shown. Figure 3 This is a schematic diagram of the structure of a magnetic sorting module provided in an embodiment of the present invention. The microfluidic system includes a fluorescence sorting module and a magnetic sorting module. The fluorescence sorting module includes a fluorescence intensity detection unit, a control unit, and a microfluidic fluorescence sorting unit. The fluorescence intensity detection unit is used to detect the fluorescence intensity of the magnetic nanomicrobial sensor sample flowing through the microchannel, and the control unit is used to control the microfluidic fluorescence sorting unit to sort out the highly fluorescent magnetic nanomicrobial sensors. The magnetic sorting module includes a uniform magnetic field established by a coil and a microfluidic magnetic sorting unit. The uniform magnetic field established by the coil is used to sort the highly fluorescent magnetic nanomicrobial sensors with uniform magnetic force distribution and then transmit them to the microfluidic magnetic sorting unit. The microfluidic magnetic sorting unit is used to sort the magnetic nanomicrobial sensors with strong fluorescence and uniform magnetic force distribution to output channels corresponding to the magnetic force magnitude range. Specifically, fluorescence sorting is used as a means of preliminary screening to quickly identify and separate strong fluorescent magnetic nanomicrobial sensors with strong fluorescent signals. Then, strong fluorescent magnetic nanomicrobial sensors with uniform magnetic distribution are sorted out according to the magnetic distribution characteristics. Finally, strong fluorescent and uniform magnetic distribution sensors are sorted into output channels corresponding to the magnetic size range according to the magnetic size characteristics.

[0035] The microfluidic system provided by an embodiment of the present invention achieves dual screening of magnetic nanomicrobial sensor samples by constructing a dual-sorting microfluidic system consisting of a fluorescence sorting module and a magnetic sorting module, combining fluorescence sorting and magnetic sorting technologies. Fluorescence sorting is used as a preliminary screening method to quickly identify and isolate strong fluorescent magnetic nanomicrobial sensors with strong fluorescence signals. Then, based on the magnetic distribution characteristics, strong fluorescent magnetic nanomicrobial sensors with uniform magnetic distribution are sorted. Furthermore, based on the magnetic magnitude characteristics, strong fluorescent and uniform magnetic distribution sensors are sorted into output channels corresponding to magnetic magnitude ranges. This allows strong fluorescent and uniform magnetic distribution sensors of different magnetic magnitudes to be sorted into target sensor groups corresponding to magnetic magnitude ranges, ensuring uniform and consistent magnetic distribution within the target sensor groups. The dual sorting mechanism of this embodiment significantly improves sorting accuracy and enhances the versatility and flexibility of the microfluidic system. It can address the poor reproducibility and low stability of sensors sorted by traditional sorting methods during application, thereby improving the accuracy and efficiency of subsequent sensor detection and has broad application prospects in various detection fields.

[0036] In one embodiment, the magnetic nanomicrobial sensor is a magnetic nanomicrobial sensor used to detect soil biological toxicity. By establishing a magnetic nanomicrobial sensor fluorescence and magnetic dual sorting microfluidic system, the problems of poor reproducibility and low stability of the magnetic nanomicrobial sensor in actual application detection can be solved, and the accuracy and efficiency of soil biological toxicity detection can be improved.

[0037] In one embodiment, magnetic nanoparticles adopt a biomimetic mineralization method instead of a traditional chemical co-precipitation method, and use Mms6 protein to prepare magnetic nanomaterials through in vitro biomimetic synthesis and mineralization, which can improve the biofriendliness and distribution uniformity of magnetic nanoparticles, reduce biological toxicity, and improve the biological activity and stability of the sensor.

[0038] In one embodiment, the entire sorting process of the microfluidic system is integrated into a single microfluidic chip, enabling automated operation, reducing human error, and improving experimental repeatability and reliability. Specifically, the microfluidic chip is equipped with multiple microchannels and microstructures, with specific microfluidic pathways, facilitating precise manipulation and sorting of magnetic nanomicroorganism sensors.

[0039] Specifically, before fluorescence sorting, the magnetic nanomicrobial sensor to be tested needs to be mixed with a sheath fluid to form a magnetic nanomicrobial sensor sample. The sheath fluid forms a sheath layer around the sample, ensuring stability and uniformity during the subsequent sorting process.

[0040] In one embodiment, the fluorescence sorting module integrates fluorescence-activated cell sorting (FACS) technology, enabling precise cell separation by identifying changes in fluorescence signals. Because the sensor microorganisms are inherently fluorescent, no additional staining or labeling is required, minimizing damage to living cells and improving the biocompatibility of the assay. Furthermore, this embodiment combines FACS with microfluidics to enhance sorting speed and accuracy.

[0041] In one embodiment, the magnetic sorting module selects strong fluorescent magnetic nanomicrobial sensors with uniform magnetic distribution through a uniform magnetic field. By controlling the magnetic field size in the microfluidic system, the magnetic nanomicrobial sensors are sorted according to their magnetic strength characteristics. The magnetic nanoparticles in the magnetic nanomicrobial sensors are evenly distributed and have consistent magnetic strength, which can effectively capture and release the magnetic particles.

[0042] like Figure 2 As shown, in the above-mentioned microfluidic system, the fluorescence sorting module also includes a fluorescence spectrum acquisition and imaging unit, which is used to collect and analyze the fluorescence signal generated by the magnetic nanomicroorganism sensor sample through self-luminescence and transmit it to the control unit. The fluorescence intensity detection unit also includes an avalanche photoelectric detection circuit, which is used to convert the fluorescence signal into an electrical signal after detecting it and send a pulse signal to the control unit.

[0043] In this embodiment, the fluorescence spectrum acquisition and imaging unit includes a spectrometer and a CCD imaging device. The spectrometer excites the magnetic nanomicroorganism sensor sample to generate fluorescence and measures the intensity and wavelength distribution of the fluorescence, thereby providing various fluorescence characteristics of the sample. The CCD imaging device can record the spatial distribution of the fluorescence signal to form a high-resolution fluorescence image. The combination of the spectrometer and CCD imaging can simultaneously obtain spectral information and spatial distribution information of the fluorescence signal, which is then transmitted to the control unit for further analysis. In addition, the fluorescence signal spontaneously generated by the magnetic nanomicroorganism sensor sample is also detected by an avalanche photodetection circuit. After detecting a strong fluorescence signal, the avalanche photodetection circuit converts it into an electrical signal and sends a pulse signal to the control unit. The control unit, combined with the fluorescence signal and electrical signal data analyzed by the fluorescence spectrum acquisition and imaging unit, can issue a sorting control signal to control the microfluidic fluorescence sorting unit to sort out the strong fluorescent magnetic nanomicroorganism sensors. Using the fluorescence spectrum acquisition and imaging unit in combination with the fluorescence intensity detection unit can improve detection accuracy and resolution.

[0044] like Figure 2 As shown, in the above microfluidic system, the fluorescence sorting module further includes a first sample channel and a first waste liquid channel, and the control unit is further configured to:

[0045] When the intensity of the fluorescent signal is greater than or equal to a preset intensity threshold, the first sample channel is controlled to open so that the strong fluorescent magnetic nanomicroorganism sensor enters the first sample channel; or

[0046] When the intensity of the fluorescent signal is less than a preset intensity threshold, the first waste liquid channel is controlled to be opened, so that the weak fluorescent magnetic nano-microorganism sensor enters the first waste liquid channel.

[0047] In this embodiment, the control unit can send a sorting control signal in combination with the fluorescence data analyzed by the fluorescence spectrum acquisition and imaging unit. The sorting control signal can be a pulse signal to control the opening and closing of the corresponding channel. When the intensity of the fluorescence signal is greater than or equal to the preset intensity threshold, the first sample channel can be controlled to open, so that the strong fluorescence magnetic nanomicroorganism sensor enters the first sample channel for subsequent processing; when the intensity of the fluorescence signal is less than the preset intensity threshold, it means that no fluorescence is detected or the fluorescence is weak. At this time, the first waste liquid channel can be controlled to open, so that the weak fluorescence magnetic nanomicroorganism sensor enters the first waste liquid channel for recovery, which can effectively improve the sorting efficiency.

[0048] In the above microfluidic system, the fluorescence sorting module further includes a sample sorting unit, which is used to control the flow of the magnetic nanomicroorganism sensor sample to deflect it to the corresponding channel.

[0049] In this embodiment, a sample sorting unit uses a non-invasive method to control the flow and sorting of magnetic nanomicrobial sensor samples, deflecting sensors that meet a specific fluorescence intensity threshold into the corresponding channel. Specifically, the sample sorting unit can include, but is not limited to, microvalves, optical tweezers, and acoustic wave devices. Using a non-invasive sorting method can maintain cell viability and integrity, which is crucial for subsequent biological research and applications.

[0050] Specifically, the strong fluorescent magnetic nanomicrobial sensor sorted by the fluorescence sorting module will be sent to the uniform magnetic field established by the coil in the magnetic sorting module for the next sorting.

[0051] like Figure 3 As shown, in the above microfluidic system, the uniform magnetic field established by the coil is used to utilize the coupling effect of magnetic field force, flow force and gravity to sort the strong fluorescent magnetic nanomicrobial sensors.

[0052] In this embodiment, the uniform magnetic field established by the coils utilizes the coupled effects of magnetic field force, flow force, and gravity to precisely sort magnetic nanoparticles based on whether the magnetic force distribution is uniform. The magnetic field strength can be adjusted by varying the magnets within the uniform magnetic field established by the coils. Flow force, generated by fluid flow and dependent on the velocity and viscosity of the fluid, provides a stable driving force for the magnetic nanoparticles while preventing excessive shear forces that could cause particle deformation or rupture. Gravity, a perpendicular force acting on the magnetic nanoparticles, depends on the density of the particles and the density of the fluid. Magnetic field force is a key factor in achieving effective displacement of the magnetic nanoparticles. By adjusting the appropriate magnetic field strength, flow velocity, and particle density, the displacement speed and direction of the magnetic nanoparticles can be optimized, thereby precisely sorting strong fluorescent magnetic nanoparticles based on whether the magnetic force distribution is uniform.

[0053] In one embodiment, the magnetic field strength is 0.1 T, which can provide sufficient magnetic field force, the flow rate is 0.5 m / s, which can provide stable flow force, and the particle density is 5000 kg / m3, ensuring that gravity has a significant effect on the displacement of particles.

[0054] like Figure 3 As shown, in the above microfluidic system, the magnetic sorting module further includes a transmitter, which is used to transmit the sorted magnetic nano-microorganism sensor with strong fluorescence and uniform magnetic distribution to the microfluidic magnetic sorting unit.

[0055] In this embodiment, the magnetic nanomicroorganism sensor with strong fluorescence and uniform magnetic force distribution, which is sorted by the uniform magnetic field established by the coil, is transmitted to the microfluidic magnetic separation unit through the transmitter, which can improve the separation efficiency.

[0056] like Figure 3 As shown, in the above-mentioned microfluidic system, the microfluidic magnetic sorting unit includes a bifurcated pipe structure and a magnet. The microfluidic magnetic sorting unit is used to adjust the flow rate and magnetic field force in the bifurcated pipe structure, control the deflection of strong fluorescence and uniform magnetic distribution nano-microorganism sensors with different magnetic force sizes, and sort them to output channels corresponding to the magnetic force size range.

[0057] In this embodiment, the bifurcated pipe structure includes two Y-shaped bifurcated pipes, one end of which is two inlets and the other end is two outlets. The upper inlet is used for the inflow of the medium solution, and the bottom inlet is used for the inflow of the magnetic nanomicroorganism sensor suspension. By changing the flow rate of the medium solution and the position of the magnet, the magnitude and direction of the magnetic field force can be controlled, thereby achieving the separation of sensors with different magnetic strengths. The sensor with larger magnetic force flows out from the upper outlet through the second sample channel and is stored through the storage device, and the sensor with smaller magnetic force is discharged from the bottom outlet through the second waste liquid channel. It can be understood that samples with no fluorescence or weak fluorescence will be guided to the waste liquid channel for disposal. The sensors with larger magnetic force are further sorted out by the microfluidic magnetic sorting unit, which can ensure the good performance of the sorted sensors.

[0058] In the above microfluidic system, the minimum distance between the magnet and the bifurcated pipe structure is within a preset distance range.

[0059] In this embodiment, a magnet is placed on the upper part of the bifurcated pipe structure to generate a local magnetic field. The magnet can be a neodymium magnet. The magnitude of the magnetic field force is controlled by controlling the distance between the magnet and the bifurcated pipe structure. The magnitude of the magnetic field force can directly affect the behavior of the magnetic fluid, including its flow, aggregation and directional arrangement in the microchannel. By ensuring that the minimum distance between the magnet and the bifurcated pipe structure is within a preset distance range, a better level of magnetic field force can be maintained, ensuring the stable flow and efficient sorting of the magnetic fluid in the microfluidic magnetic field system, improving the sorting efficiency and accuracy, and thus meeting the needs of practical applications.

[0060] The above-mentioned microfluidic system also includes a magnetic characterization module, which is used to characterize the magnetic nano-microorganism sensor with strong fluorescence and uniform magnetic distribution after sorting by the microfluidic magnetic sorting unit.

[0061] In this embodiment, after the magnetic sorting module has selected the optimal target sensors, the magnetic characterization module can be used to characterize the selected magnetic nanomicrobial sensors with strong fluorescence and uniform magnetic distribution. By characterizing the sensor's surface morphology, luminescence intensity, negative magnetic effect, and binding state before and after sorting, the target sample recovery rate, magnetic magnitude, and distribution are analyzed, and the most optimal parameter settings are selected. This, in turn, identifies the magnetic nanomicrobial sensor with the best performance, facilitating stability and reliability in subsequent applications. Specifically, the magnetic characterization module can include, but is not limited to, a vibrating sample magnetometer, a transmission electron microscope, a scanning electron microscope, and an atomic force microscope.

[0062] In some embodiments, by comparing different sorting schemes, it can be determined that the sorting effect of the embodiment of the present invention is better.

[0063] Sorting scheme 1: Comprehensive sorting scheme combining fluorescence sorting and magnetic sorting

[0064] The specific experimental steps are as follows: the prepared magnetic nanomicrobial sensor samples are injected into the microchannels of the microfluidic chip, fluorescence sorting is performed first to screen out sensors with high luminescence intensity, and then magnetic sorting is performed to inject the sensors with high luminescence intensity into a uniform magnetic field. After screening out sensors with high luminescence intensity with uniform magnetic distribution, the sensors with high luminescence intensity with uniform magnetic distribution are injected into the microchannels of the microfluidic chip to ensure that the magnetic distribution of the sensors is uniform and the size is consistent, and then the sorted sensors are characterized and analyzed.

[0065] The sorting effect is: all sorted sensors show high luminous intensity, and the luminous intensity distribution is uniform; all sorted sensors have uniform magnetic distribution and consistent size, and have good magnetic performance.

[0066] Sorting solution 2: Comprehensive sorting solution combining fluorescence sorting and magnetic size sorting

[0067] The specific experimental steps are as follows: inject the prepared magnetic nanomicrobial sensor samples into the microchannel of the microfluidic chip, perform fluorescence sorting first to screen out sensors with high luminescence intensity, then perform magnetic sorting, inject the high luminescence intensity sensors into the microchannel of the microfluidic chip to ensure that the magnetic force of the sensors is consistent, and then characterize and analyze the sorted sensors.

[0068] The sorting effect is: although sensors with high luminous intensity and consistent magnetic force are screened out, the uniformity of magnetic force distribution is not screened, and some sensors are eliminated due to uneven magnetic force.

[0069] Sorting method 3: Fluorescence sorting only

[0070] The specific experimental steps are as follows: inject the prepared magnetic nanomicrobial sensor samples into the microchannel of the microfluidic chip, perform only fluorescence sorting, screen out sensors with high luminescence intensity, and characterize and analyze the sorted sensors.

[0071] The sorting effect is: although sensors with high luminous intensity were screened out, the magnetic force was not screened, and some sensors were eliminated due to uneven magnetic force or inconsistent size.

[0072] Sorting scheme 4: magnetic separation only

[0073] The specific experimental steps are as follows: inject the prepared magnetic nanomicrobial sensor samples into the microchannel of the microfluidic chip, perform only magnetic sorting, and characterize and analyze the sorted sensors.

[0074] The sorting effect is: although the magnetic force of the sensors is evenly distributed and of the same size, the luminous intensity is unevenly distributed, and the luminous intensity of some sensors is low, which does not meet the requirements.

[0075] It should be noted that Sorting Scheme 1, which takes into account both luminous intensity and magnetic distribution and size performance, has a higher recovery rate, and all recovered sensors meet the requirements. Sorting Scheme 2, which does not consider magnetic distribution performance, has a lower recovery rate, and some recovered sensors do not meet the requirements. Sorting Schemes 3 and 4, which only consider a single performance (luminous intensity or magnetic force), have the lowest recovery rates, and most recovered sensors do not meet the requirements. Sorting Scheme 1 provided by the present invention has obvious advantages in achieving the goal of "sorting target sensors with uniform magnetic distribution, consistent size, and excellent luminous intensity." The scheme not only improves the luminous intensity and magnetic performance of the sensors, but also improves the recovery rate, providing strong support for the preparation and application of magnetic nanomicrobial sensors.

[0076] The microfluidic system of the embodiment of the present invention can achieve accurate sorting of magnetic nanomicrobial sensors, improve the purity and activity of the sorting, and is of great significance for improving the accuracy and efficiency of soil biological toxicity detection.

[0077] In a second aspect, an embodiment of the present invention provides a microfluidic sorting method, which is applied to the microfluidic system of the first aspect, and specifically includes:

[0078] The prepared magnetic nanomicrobial sensor sample is injected into the microchannel of the microfluidic chip;

[0079] Performing fluorescence sorting on the magnetic nanomicroorganism sensor samples by the fluorescence sorting module to screen out strong fluorescent magnetic nanomicroorganism sensors;

[0080] The strong fluorescent magnetic nanomicrobial sensors are magnetically sorted by the magnetic sorting module to first screen out strong fluorescent magnetic nanomicrobial sensors with uniform magnetic distribution, and then the strong fluorescent sensors with different magnetic strengths and uniform magnetic distribution are sorted into target sensor groups corresponding to the magnetic strength range.

[0081] According to the microfluidic sorting method provided by the embodiment of the present invention, by combining fluorescence sorting and magnetic sorting technology, a dual screening of magnetic nanomicrobial sensor samples is achieved. Fluorescence sorting is used as a means of preliminary screening to quickly identify and separate strong fluorescent magnetic nanomicrobial sensors with strong fluorescence signals. Then, after sorting out strong fluorescent magnetic nanomicrobial sensors with uniform magnetic distribution according to the magnetic force distribution characteristics, the strong fluorescent and uniform magnetic distribution sensors are sorted into output channels corresponding to the magnetic force range according to the magnetic force size characteristics, thereby achieving the goal of sorting strong fluorescent and uniform magnetic distribution magnetic nanomicrobial sensors of different magnetic force sizes into target sensor groups corresponding to the magnetic force size range, ensuring that the magnetic force distribution of sensors in the corresponding target sensor group is uniform and consistent in size. The dual sorting mechanism of this embodiment significantly improves the sorting accuracy, can solve the problems of poor reproducibility and low stability of sensors sorted by traditional sorting methods during application, and is conducive to improving the accuracy and efficiency of subsequent sensor detection. It has broad application prospects in various detection fields.

[0082] The system embodiments described above are merely illustrative. The modules or units described as separate components may or may not be physically separate, and the components shown as units may or may not be physical units, i.e., they may be located in one location or distributed across multiple network elements. Some or all of the modules may be selected based on actual needs to achieve the objectives of this embodiment. Persons of ordinary skill in the art will be able to understand and implement the present invention without inventive effort.

[0083] Through the description of the above embodiments, those skilled in the art can clearly understand that each embodiment can be implemented by means of software plus a necessary general hardware platform, or of course, by hardware. Based on this understanding, the essence of the above technical solution or the part that contributes to the existing technology can be embodied in the form of a software product. The computer software product can be stored in a computer-readable storage medium, such as ROM / RAM, a magnetic disk, an optical disk, etc., and includes a number of instructions for enabling a computer device (which can be a personal computer, a server, or a network device, etc.) to execute the methods described in each embodiment or certain parts of the embodiments.

[0084] The embodiments of the present invention are described in detail above with reference to the accompanying drawings. However, the present invention is not limited to the above embodiments. Various changes can be made within the scope of knowledge possessed by ordinary technicians in the technical field without departing from the spirit of the present invention.

Claims

1. A microfluidic system, characterized in that: include: The fluorescence sorting module includes a fluorescence intensity detection unit, a control unit, and a microfluidic fluorescence sorting unit. The fluorescence intensity detection unit is used to detect the fluorescence intensity of the magnetic nanomicroorganism sensor sample flowing through the microchannel. The control unit is used to control the microfluidic fluorescence sorting unit to sort out the strong fluorescent magnetic nanomicroorganism sensor. The magnetic sorting module includes a uniform magnetic field established by a coil and a microfluidic magnetic sorting unit. The uniform magnetic field established by the coil is used to sort strong fluorescent magnetic nanomicroorganism sensors with uniform magnetic force distribution and then transmit them to the microfluidic magnetic sorting unit. The microfluidic magnetic sorting unit is used to sort the strong fluorescent magnetic nanomicroorganism sensors with uniform magnetic force distribution to output channels corresponding to the magnetic force size range.

2. The microfluidic system according to claim 1, characterized in that The fluorescence sorting module also includes a fluorescence spectrum acquisition and imaging unit, which is used to collect and analyze the fluorescence signal spontaneously generated by the magnetic nanomicroorganism sensor sample and transmit it to the control unit. The fluorescence intensity detection unit also includes an avalanche photoelectric detection circuit, which is used to convert the fluorescence signal into an electrical signal after detecting it and send a pulse signal to the control unit.

3. The microfluidic system according to claim 2, characterized in that The fluorescence sorting module further includes a first sample channel and a first waste liquid channel, and the control unit is further configured to: When the intensity of the fluorescent signal is greater than or equal to a preset intensity threshold, the first sample channel is controlled to open so that the strong fluorescent magnetic nano-microorganism sensor enters the first sample channel; or When the intensity of the fluorescent signal is less than a preset intensity threshold, the first waste liquid channel is controlled to be open, so that the weak fluorescent magnetic nano-microorganism sensor enters the first waste liquid channel.

4. The microfluidic system according to claim 3, characterized in that The fluorescence sorting module further includes a sample sorting unit, which is used to control the flow of the magnetic nano-microorganism sensor sample to be deflected to a corresponding channel.

5. The microfluidic system according to claim 1, characterized in that The uniform magnetic field established by the coil is used to utilize the coupling effect of magnetic field force, flow force and gravity to sort the strong fluorescent magnetic nano-microorganism sensors based on whether the magnetic force is uniformly distributed.

6. The microfluidic system according to claim 5, characterized in that The magnetic sorting module further comprises a transmitter, which is used to transmit the sorted magnetic nano-microorganism sensor with strong fluorescence and uniform magnetic distribution to the microfluidic magnetic sorting unit.

7. The microfluidic system according to claim 1, characterized in that The microfluidic magnetic sorting unit includes a bifurcated pipe structure and a magnet. The microfluidic magnetic sorting unit is used to adjust the flow rate and magnetic field force in the bifurcated pipe structure, control the deflection of strong fluorescence and magnetic nano-microorganism sensors with uniform magnetic force distribution of different magnetic force magnitudes, and sort them into output channels corresponding to the magnetic force magnitude range.

8. The microfluidic system according to claim 7, characterized in that The minimum distance between the magnet and the bifurcated pipe structure is within a preset distance range.

9. The microfluidic system according to claim 1, characterized in that It also includes a magnetic characterization module, which is used to characterize the magnetic nano-microorganism sensor with strong fluorescence and uniform magnetic distribution after sorting by the microfluidic magnetic sorting unit.

10. A microfluidic sorting method based on the microfluidic system according to any one of claims 1 to 9, characterized in that: include: The prepared magnetic nanomicrobial sensor sample is injected into the microchannel of the microfluidic chip; Performing fluorescence sorting on the magnetic nanomicroorganism sensor samples by the fluorescence sorting module to screen out strong fluorescent magnetic nanomicroorganism sensors; The strong fluorescent magnetic nanomicroorganism sensors are magnetically sorted by the magnetic sorting module, and the strong fluorescent magnetic nanomicroorganism sensors with uniform magnetic distribution are sorted out by the uniform magnetic field generated by the coil. Then, the strong fluorescent magnetic nanomicroorganism sensors with uniform magnetic distribution and different magnetic strengths are sorted into the target sensor group corresponding to the magnetic strength range.

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