Milk protein full-scene visual instant detection device and detection method

Abstract

The invention discloses a milk protein full-scene visual instant detection device, a detection method and a control terminal.The detection device comprises a shell, a gland is arranged on the top of the shell, an observation window is formed in the gland, a micro-fluidic chip is arranged in the shell, and a detection part is formed in the micro-fluidic chip; the detection part comprises an anode buffer solution pool, a channel and a cathode buffer solution pool which are sequentially communicated, a mixed solution containing a to-be-detected sample is added into the channel through the anode buffer solution pool, and the constant temperature of the micro-fluidic chip is ensured through a constant-temperature assembly; after the mixed solution is converted into a solid state, performing electrophoresis operation through an electrophoresis assembly, photographing to obtain an observation window image, calculating to obtain an MRB migration distance, and substituting the MRB migration distance into the standard curve to finally obtain the protein content of the to-be-detected sample. The device is small in size and convenient to carry, eliminates the influence of temperature and time on a detection result, is simple to operate, can simultaneously detect various dairy products with unknown protein contents, improves the detection efficiency, and saves the cost.

Description

Technical Field

[0001] The present disclosure relates to the technical field of protein detection, and in particular to a full-scene visual instant detection device and method for milk protein. Background Art

[0002] Milk and various dairy products such as cream, cheese, yogurt, and milk powder are important food sources for people in all countries, providing the human body with essential trace elements and nutrients such as protein, vitamins, calcium, and potassium. Dairy products have both nutritional value and physiological functions, and occupy an important position in dietary nutrition. Protein is an important component of dairy products. Its content is not only related to the nutritional value of dairy products, but also one of the important indicators for measuring the quality of dairy products. At present, some methods for detecting protein content have been developed, such as Kjeldahl nitrogen determination method, Dumas method, Coomassie brilliant blue method, Folin phenol method, BCA method, biuret method, and near-infrared spectroscopy. However, there are some problems with the relevant detection technologies at present, such as Kjeldahl nitrogen determination method and Dumas method are cumbersome to operate, long detection time, and are interfered by non-protein nitrogen. Although the other methods are not interfered by non-protein nitrogen, they are not suitable for high-throughput instant detection due to cumbersome operation, high cost, long detection time, and large sample consumption.

[0003] The prior art provides a protein electrophoresis titration method for detecting dairy products. Electrophoresis is a phenomenon in which charged ions migrate under the action of an electric field and react with the carboxyl groups of proteins fixed in a gel. The change in temperature has a great influence on the migration rate of ions in an electric field. Therefore, the difference caused by different temperatures cannot make the detection of the protein content in milk calculated by a unified reaction boundary migration rate.

[0004] At the same time, as the temperature increases, the diffusion effect increases, and the randomness of the diffusion effect leads to the deterioration of the stability of the reaction boundary interface migration, resulting in inaccurate measurement of the reaction boundary movement distance, which in turn affects the protein content result calculated based on the reaction boundary movement distance. When the temperature is relatively low, the migration rate of ions is relatively slow. Therefore, when other conditions are the same, the lower the temperature, the slower the migration rate of the moving reaction boundary. Therefore, in the process of protein electrophoresis titration, the impact of some relative errors on the test results will be amplified, which will also lead to inaccurate measurement results.

[0005] To this end, we proposed a full-scene visual instant detection device and method for milk protein. Summary of the invention

[0006] In view of the above-mentioned defects or deficiencies in the prior art, it is desired to provide a full-scene visual instant detection device and method for milk protein.

[0007] In the first aspect, the present application provides a full-scene visual instant detection device for milk protein, comprising: A shell, wherein the top of the shell is open, and a pressure cover is movably provided at the opening, and an observation window is provided on the pressure cover, and the observation window and the pressure cover are different in color; A microfluidic chip, wherein the microfluidic chip is arranged inside the housing, and at least three detection parts are opened on the top of the microfluidic chip, and the detection parts are used to hold a mixed solution, wherein the mixed solution includes a sample to be detected, an indicator, a background buffer solution and a gel solution; The detection part includes an anode buffer pool, a cathode buffer pool and a channel, wherein the channel is located between the anode buffer pool and the cathode buffer pool, and both ends of the channel are connected to the anode buffer pool and the cathode buffer pool respectively, the anode buffer pool is a circular structure, and the cathode buffer pool is a square structure; A constant temperature component, the constant temperature component is arranged inside the housing and located at the bottom of the microfluidic chip, and a receiving groove is arranged on the constant temperature component for receiving the microfluidic chip; An electrophoresis component is arranged above the microfluidic chip and is used for performing electrophoresis on the sample to be detected in the detection part.

[0008] According to the technical solution provided in the embodiment of the present application, the constant temperature component includes a heat conductive block, the top of the heat conductive block is provided with the receiving groove adapted to the microfluidic chip, the bottom of the heat conductive block is provided with a temperature control unit for heating or cooling the heat conductive block, the bottom of the temperature control unit is provided with a heat dissipation block, and the bottom of the heat dissipation block has a plurality of heat dissipation fins.

[0009] According to the technical solution provided in the embodiment of the present application, a mounting plate is fixedly connected to the inner wall of the outer shell, which is located at the bottom of the heat sink, and a through hole is opened on the mounting plate corresponding to the heat sink, and the constant temperature component also includes a heat sink, which is arranged at the bottom of the mounting plate and corresponding to the through hole.

[0010] According to the technical solution provided in the embodiment of the present application, the electrophoresis assembly includes an electrode PCB board, which is arranged at the bottom of the observation window. Electrodes are arranged at the bottom of the electrode PCB board, and the electrodes include an anode corresponding to the anode buffer pool and a cathode corresponding to the cathode buffer pool. The electrode PCB board is also penetrated by a through opening corresponding to the microfluidic chip.

[0011] According to the technical solution provided in the embodiment of the present application, a power supply is provided on the inner wall of the shell, a control module is provided on the inner wall of the bottom of the shell, the control module is electrically connected to the power supply, and the control module is electrically connected to the temperature control unit and the heat sink, and the control module has a relay, which is electrically connected to the electrode PCB board for controlling the time of electrophoresis.

[0012] According to the technical solution provided in the embodiment of the present application, an anode buffer is added to the anode buffer pool, and the anode buffer is and The cathode buffer pool is added with a cathode buffer, and the cathode buffer is an alkaline solution having ions, the indicator contacts the The ions change color.

[0013] According to the technical solution provided in the embodiment of the present application, the detection device further includes: a control terminal, the control terminal is electrically connected to the control module, the control terminal has a control panel, and the control panel is provided with a start button, an electrophoresis button, a photo button and a calculation button; The start button is used to start the detection device, power on the detection device, and control the temperature control unit to work through the control module, so that the microfluidic chip reaches the target temperature and maintains the temperature for a first set time; The electrophoresis button is used to operate the control module to energize the electrode PCB board, so that the electrode is energized to perform electrophoresis on the mixed solution, and the electrode PCB board is powered off after a second set time. The camera button is used to operate the camera module to take a photo of the observation window and obtain an image; The calculation button is used to operate the processing module to obtain the length value of the color change area in the channel.

[0014] In a second aspect, the present application provides a detection method, which uses the milk protein full-scene visual instant detection device, and the detection method comprises: S01, open the gland, mix the sample to be detected, the indicator, the background buffer solution and the gel solution to form a mixed solution, and inject the mixed solution into the channel through the anode buffer pool; S02, powering on the detection device, controlling the temperature control unit through the control module to heat the microfluidic chip to a target temperature, and maintaining the temperature for a first set time; S03, injecting anode buffer and cathode buffer into the anode buffer pool and cathode buffer pool respectively, and covering them with glands; S04, energizing the electrode PCB board through the control module, so that the electrode is energized to perform electrophoresis on the mixed solution, and maintaining the second set time; S05, taking a photo of the observation window to obtain an image, and obtaining a length value of the color-changing area in the channel according to the image; S06. Obtain the protein content in the sample to be detected according to the length value and the standard relationship curve between the protein content and the MRB migration distance.

[0015] According to the technical solution provided in the embodiment of the present application, the length value of the color change area in the image acquisition channel includes: Determine the target area through Canny edge detection and contour detection; the target area is the area inside the observation window included in the image; Affine transformation is performed on the target area, and MRB is extracted through masking. The migration distance of MRB is detected through contour detection, and the MRB migration distance is used as the length value of the color change area in the channel.

[0016] According to the technical solution provided in the embodiment of the present application, the method further includes: Using a plurality of bovine dairy products with known protein contents as samples to be tested, and using the detection device to detect the MRB migration distances corresponding to the plurality of bovine dairy products with known protein contents; A standard relationship curve between the protein content and the MRB migration distance was established by taking the MRB migration distance as the abscissa and the protein content of the dairy product with known protein content as the ordinate.

[0017] In summary, the present technical solution specifically discloses a full-scene visualized instant detection device and a detection method for milk protein. The detection device includes a housing, a pressure cover is arranged on the top, an observation window is arranged on the pressure cover, a microfluidic chip is arranged inside the housing, and at least three detection parts are provided on the microfluidic chip. The detection part includes an anode buffer pool, a channel and a cathode buffer pool connected in sequence. The anode buffer pool is a circular structure, and the cathode buffer pool is a square structure. The constant temperature component is arranged inside the housing to ensure that the temperature of the microfluidic chip is constant, and the electrophoresis component is arranged inside the housing for performing electrophoresis operation; The detection device can detect the protein content of a dairy product with an unknown protein content, obtain a sample to be detected from the dairy product with an unknown protein content, mix it with an indicator, a background buffer solution and a gel solution to form a mixed solution, inject the mixed solution into a channel through an anode buffer pool, control a constant temperature component through a control terminal to keep the temperature of a microfluidic chip constant, add an anode buffer solution and a cathode buffer solution to the anode buffer pool and a cathode buffer pool respectively, control the electrophoresis component to perform electrophoresis on the mixed solution through a control terminal, take a photo after electrophoresis to obtain an observation window image, obtain a length value of a color change area in the channel after calculation, and finally obtain the protein content of the sample to be detected according to the length value and a standard relationship curve between the protein content and the MRB migration distance, thereby obtaining the protein content of the dairy product with an unknown protein content; The device is small in size and easy to carry, and can ensure constant detection temperature and detection time. It can draw a standard relationship curve based on the protein content of dairy products with known protein content and the corresponding MRB migration distance, and reversely infer the protein content in the dairy products with unknown protein content based on the MRB migration distance of dairy products with unknown protein content. The device is simple to operate and can simultaneously detect multiple dairy products with unknown protein contents, thereby improving detection efficiency and saving costs. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Other features, objects and advantages of the present application will become more apparent by reading the detailed description of non-limiting embodiments made with reference to the following drawings: Figure 1 This is a diagram of the internal structure of the full-scenario visual instant detection device for milk protein.

[0019] Figure 2 This is an exploded view of the full-scene visualization of the instant detection device for milk protein.

[0020] Figure 3 Schematic diagram of the microfluidic chip.

[0021] Figure 4 Schematic diagram of the heat conduction block.

[0022] Figure 5 The detection method steps.

[0023] Numbers in the figure: 1. Shell; 2. Pressure cover; 3. Observation window; 4. Microfluidic chip; 5. Anode buffer tank; 6. Cathode buffer tank; 7. Channel; 8. Heat conduction block; 9. Temperature control unit; 10. Heat sink; 11. Mounting plate; 12. Heat sink; 13. Electrode PCB board; 14. Electrode; 15. Power supply; 16. Control module; 17. Receiving slot. DETAILED DESCRIPTION

[0024] The present application is further described in detail below in conjunction with the accompanying drawings and embodiments. It is to be understood that the specific embodiments described herein are only used to explain the relevant invention, rather than to limit the invention. It is also necessary to explain that, for ease of description, only the parts related to the invention are shown in the accompanying drawings.

[0025] It should be noted that, in the absence of conflict, the embodiments and features in the embodiments of the present application can be combined with each other. The present application will be described in detail below with reference to the accompanying drawings and in combination with the embodiments.

[0026] Embodiment 1 Please refer to Figures 1 to 4 As shown, the milk protein full-scene visual instant detection device includes: The housing 1 has an opening at the top, and a gland 2 is movably arranged at the opening. The housing 1 has two opposite side walls, and both of the two opposite side walls at the top are provided with a taking groove, so that the gland 2 can be taken off through the taking groove; Furthermore, an observation window 3 is provided on the gland 2; A microfluidic chip 4 is arranged inside the housing 1, and three detection parts are arranged on the top of the microfluidic chip 4, and the detection parts are used to hold a mixed solution, and the mixed solution includes a sample to be detected, an indicator, a background buffer solution and a gel solution, wherein the sample to be detected is a dairy product to be detected, the indicator is a phenolphthalein indicator, the background buffer solution is a potassium chloride solution, and the gel solution is a PAGE gel; Optionally, the size of the microfluidic chip 4 is 31mm*31mm*4mm; the microfluidic chip 4 can be made of PC material; Further, an anode buffer pool 5, a cathode buffer pool 6 and a channel 7, wherein the channel 7 is located between the anode buffer pool 5 and the cathode buffer pool 6, and both ends of the channel 7 are connected to the anode buffer pool 5 and the cathode buffer pool 6 respectively; Optionally, the channel 7 has a size of 15 mm*0.5 mm*0.5 mm, the anode buffer pool 5 has a circular structure, and the cathode buffer pool 6 has a square structure; Thus, the mixed solution is injected into the channel 7 through the anode buffer pool 5, and the contact angle between the mixed solution and the boundary of the channel 7 is less than 90°. Under the action of capillary force, the mixed solution can complete self-injection, eliminating the need to use a pump to drive the mixed solution injection, further reducing the volume of the detection device and making the detection process more convenient. The mixed solution moves in channel 7 to the junction of channel 7 and cathode buffer tank 6. Since cathode buffer tank 6 is a square structure, the cross-section forms a mutation with a mutation angle of 90°. Therefore, the capillary valve formed at the mutation point has a strong intercepting effect on the mixed solution in channel 7, thereby preventing the mixed solution from entering cathode buffer tank 6.

[0027] A constant temperature component, which is arranged inside the housing 1 and is used to ensure that the temperature of the mixed solution in the microfluidic chip 4 is constant; Specifically, the constant temperature component includes a heat conducting block 8, and a receiving groove 17 adapted to the microfluidic chip 4 is opened on the top of the heat conducting block 8, so that the receiving groove 17 can fit the microfluidic chip 4 and evenly conduct heat to the bottom and surrounding of the microfluidic chip 4, ensuring that the microfluidic chip 4 can be in a constant temperature detection environment, thereby improving the detection accuracy; Optionally, the heat conducting block 8 is made of metal; Furthermore, through grooves are provided on two opposite side walls of the heat conducting block 8, and the through grooves are connected to the receiving groove 17. Since the microfluidic chip 4 needs to be replaced every time the dairy product is tested, the through grooves are provided to facilitate the removal and replacement of the microfluidic chip 4. Furthermore, the thermostatic assembly further includes a temperature control unit 9, which is arranged at the bottom of the heat conductive block 8. Optionally, the temperature control unit 9 is a TEC cooling sheet, and is attached to the bottom of the heat conductive block 8 through thermal grease. The side of the temperature control unit 9 close to the heat conductive block 8 is a working surface, and the temperature control unit 9 controls the working surface to be a cooling mode or a heating mode according to the direction of the current. Furthermore, the thermostatic assembly further includes a heat sink 10, which is disposed at the bottom of the temperature control unit 9. Optionally, the heat sink 10 is adhered to the bottom of the temperature control unit 9 by thermal grease, and the bottom of the heat sink 10 has a plurality of heat sink fins. Further, a mounting plate 11 is fixedly connected to the inner wall of the housing 1, and the mounting plate 11 is located at the bottom of the heat sink 10. The mounting plate 11 can provide support for the heat sink 10. The thermostatic assembly also includes a heat sink 12, which is arranged at the bottom of the mounting plate 11 and is optionally installed by screws. A through hole is opened through the mounting plate 11, and the through hole is arranged corresponding to the heat sink 10 and the heat sink 12. The heat sink 12 has an input end and an output end, and the input end is close to the heat sink 10. The heat sink 12 can be optionally a fan. When the working surface is in cooling mode, the other side is in heating mode. If the temperature of the working surface is too high, the temperature control unit 9 will burn out and cannot work normally. Therefore, when the temperature control unit 9 is in cooling mode, it is necessary to cool the other side to prevent the temperature from being too high. The heat sink 10 and thermal grease can quickly transfer heat. By starting the heat sink 12, the heat can be absorbed and transferred to the output end through the through hole, thereby achieving rapid cooling of the temperature control unit 9.

[0028] An electrophoresis component, used for performing electrophoresis on the mixed solution in the detection part; Specifically, the electrophoresis assembly includes an electrode PCB board 13, which is arranged at the bottom of the observation window 3, and an electrode 14 is arranged at the bottom of the electrode PCB board 13. The electrode 14 includes an anode corresponding to the anode buffer pool 5 and a cathode corresponding to the cathode buffer pool 6. The anode extends into the anode buffer pool 5, and the cathode extends to the cathode buffer pool 6; Furthermore, a through hole is formed through the electrode PCB board 13 , which corresponds to the microfluidic chip 4 and has a size that matches the microfluidic chip 4 , so that the result of electrophoresis in the microfluidic chip 4 can be observed through the observation window 3 .

[0029] It also includes a power supply 15 and a control module 16. The power supply 15 is arranged on the inner wall of the housing 1 and is used to power the entire device. A charging hole is arranged on the side wall of the housing 1 so that the power supply 15 can be charged. Optionally, the power supply 15 is a lithium battery with an operating voltage of 24V. Further, the control module 16 is arranged on the inner wall of the bottom of the housing 1, and is electrically connected to the power supply 15. The control module 16 has a relay, and the electrode PCB board 13 is electrically connected to the relay, thereby realizing connection with the control module 16. Thus, the power-on time of the electrode 14 can be accurately controlled through the control module 16; Furthermore, the control module 16 is electrically connected to the temperature control unit 9, and can realize the positive and negative rotation of the output current direction through the H-bridge circuit, thereby controlling the working surface of the temperature control unit 9 to heat or cool; It should be noted that the control module 16 sets a target temperature, which is the temperature of the sample to be detected by the detection device. By comparing the target temperature with the detected actual temperature of the receiving groove 17 of the heat conductive block 8, the current direction is controlled to realize that the working surface of the temperature control unit 9 is in the heating mode or the cooling mode; Furthermore, the control module 16 detects the actual temperature of the containing slot 17 fed back by the NTC thermistor through the CPU, controls the H-bridge circuit to realize the forward and reverse rotation of the output current direction, thereby controlling the working surface of the temperature control unit 9 to be in the heating mode or the cooling mode, and controls the output power through the PID algorithm according to the difference between the target temperature and the actual temperature, thereby achieving the purpose of maintaining a constant temperature.

[0030] It should be noted that the device has a size of 10cm*12cm*16cm, is small, easy to carry, and can be used for timely detection.

[0031] It should be noted that the observation window 3 and the pressure cover 2 have different colors and are clearly distinguished. Optionally, the observation window 3 is black and the pressure cover 2 is white.

[0032] The detection device also includes a control terminal for controlling the detection device, taking pictures of the observation window 3, and finally obtaining the length value of the color change area in the channel; Further, the control terminal is connected to the control module 16, optionally via Bluetooth, and the control terminal has a control panel, on which a start button, an electrophoresis button, a photo button and a calculation button are arranged; The start button is used to start the detection device, power on the detection device, and control the temperature control unit 9 through the control module 16 to heat or cool the microfluidic chip 4, so that the temperature of the microfluidic chip 4 reaches the target temperature and maintains the first set time to convert the mixed solution into a solid state; The electrophoresis button is used to operate the control module 16 to energize the electrode PCB board 13, so that the electrode is energized to facilitate the start of the electrophoresis operation, and then the electrode PCB board 13 is powered off after the second set time. The camera button is used to operate the camera module to take a photo of the mixed solution after electrophoresis to obtain an image; The calculation button is used to operate the processing module to obtain the length value of the color change area in the channel; Optionally, the control terminal may be a mobile phone APP, so the camera module and the processing module are both arranged on the mobile phone.

[0033] Embodiment 2 A detection method, using the milk protein full-scene visual instant detection device mentioned in Example 1, can detect dairy products with unknown protein content to obtain the protein content of the dairy products; This detection method is a protein electrophoresis titration method developed based on the concept of mobile reaction boundaries. The protein content is detected on a protein electrophoresis titration chip, and the protein molecules are fixed using PAGE gel to ensure that the protein does not migrate under the action of the electric field. At the same time, the ions in channel 7 ( ) and protein carboxyl groups ( ) reaction, using the color change of phenolphthalein to indicate the area where the reaction has occurred. Therefore, this method reduces the amount of sample consumed and also shortens the detection time.

[0034] Moving Reaction Boundary (hereinafter referred to as MRB), by mixing the sample to be detected, the indicator, the background buffer and the gel solution to obtain a mixed solution, the mixed solution is injected into the channel 7 through the anode buffer pool 5, and under the action of the capillary valve, the mixed solution will not enter the cathode buffer pool 6, a first set time is set, after the first set time, the gel solution completes polymerization, and the mixed solution changes from liquid to solid, thereby being able to fix the protein in the sample to be detected, avoiding protein migration in the subsequent electrophoresis process, by respectively injecting the anode buffer and the cathode buffer into the gel solution and the cathode buffer pool 6, and then energizing the electrophoresis component through the control module 16 to achieve electrophoresis operation; Optionally, the anode buffer is and The cathode buffer is an alkaline solution with ions, thus, during electrophoresis, Ions migrate through the electric field, enter channel 7 from cathode buffer pool 6, and react with proteins. Since the indicator is phenolphthalein, Ions and protein carboxyl groups ( ) The area where the reaction is completed can change color, intuitively reflecting the color change area.

[0035] The second set time is set, which is the electrophoresis time. Under the second set time, the MRB moving distance of different types of proteins can be calculated by formula (1): (1) in, for Ion concentration; for Ion mobility; is the cross-sectional area of ​​channel 7; Set duration for the second one; is the protein content; is the relative molecular weight of the protein; is the amount of carboxyl groups contained in each protein molecule; Obviously, different proteins The values ​​are different, resulting in The values ​​are different, so formula (1) can be expressed as: (2) Under the same microfluidic chip 4 and the same electrophoresis time (second set time length), and is a constant; Under the given experimental conditions, the cathode buffer was identical, i.e. is a constant; Since the composition and proportion of milk protein are relatively fixed, and is considered as a constant, so two constants can be defined to simplify the calculation:

[0036]

[0037] Therefore, formula (2) can be expressed as: (3) Temperature changes can affect the mass transfer during electrophoresis and have an impact on MRB migration. Under given conditions, the migration speed of ions is affected by temperature. The electrical migration of ions in a solution depends on the viscosity of the solution, the ionic strength of the solution, and the degree of ion dissociation. For ions in an infinitely dilute solution, the electric field force and the blocking friction force act on them. The ion migration rate can be expressed as: (4) in, represents the electrical mobility of ions in an infinitely dilute solution, is the charge of the ion, represents the electron charge, is the dynamic viscosity of the solution, is the hydraulic radius of the ion in solution.

[0038] Formula (4) describes the inertial force on a sphere in a simple continuous fluid. From the above formula, it can be seen that the change in solution viscosity will cause an approximately inverse proportional change in ion mobility. The relationship between viscosity and temperature is expressed by formula (5): (5) in, and Ambient temperature and reference temperature The viscosity of water under At 20°C, At 5°C, we can get The viscosity is 1.514, indicating that the viscosity increases by 51.4% at 5°C relative to 20°C. It is calculated that the ambient temperature varies between 10°C and 40°C, which will lead to a 45%-60% deviation in ion mobility, and the low / high temperature will reduce / increase the ion mobility, thereby shortening / lengthening the migration distance of MRB.

[0039] In summary, it can be concluded that when the temperature is constant and other conditions are the same, the protein content of unknown dairy products can be calculated by the MRB migration distance. Therefore, at a certain constant temperature, using a variety of milk samples with known protein content, and controlling the electrophoresis voltage and time and other conditions to be the same, a standard curve of protein content and MRB migration distance can be drawn. After that, protein electrophoresis titration can be performed under the same experimental conditions as the standard curve, and the milk sample with unknown protein content can be tested by measuring the MRB migration distance.

[0040] like Figure 5 As shown, the detection method specifically includes the following steps: S01, open the gland 2, mix the sample to be detected, the indicator, the background buffer solution and the gel solution to form a mixed solution, and inject the mixed solution into the channel 7 through the anode buffer pool 5; Specifically, a sample to be tested is obtained from a dairy product with unknown protein content, the sample to be tested, an indicator, a background buffer solution and a gel solution are mixed to form a mixed solution, the gland 2 is opened, and the mixed solution is injected into the channel 7 through the anode buffer tank 5, and under the action of the capillary valve, the mixed solution will not enter the cathode buffer tank 6; S02, powering on the detection device, controlling the temperature control unit 9 through the control module 16 to heat the microfluidic chip 4 to a target temperature, and maintaining the temperature for a first set time; Specifically, the detection device is powered on by the power supply 15 to obtain the actual temperature of the microfluidic chip 4 and compare it with the target temperature. According to the comparison result, the temperature control unit 9 is controlled by the control module 16 to heat or cool the working surface of the temperature control unit 9, so that the temperature of the microfluidic chip finally reaches the target temperature and is maintained for a first set time, so that the mixed solution changes from liquid to solid, thereby fixing the protein and preventing the migration of the protein.

[0041] S03, injecting anode buffer and cathode buffer into anode buffer pool 5 and cathode buffer pool 6 respectively, and covering with gland 2; Specifically, after the mixed solution is converted into a solid state, an anode buffer and a cathode buffer are respectively injected into the anode buffer tank 5 and the cathode buffer tank 6, and then the pressure cover 2 is covered, so that the anode can extend into the anode buffer tank 5 and contact the anode buffer, and the cathode can extend into the cathode buffer tank 6 and contact the cathode buffer, thereby realizing a closed loop; S04, energizing the electrode PCB board 13 through the control module 16, so that the electrode is energized to perform electrophoresis on the mixed solution, and maintaining the second set time; Specifically, the control module 16 energizes the electrode PCB board 13, so that the electrode is energized, and the anode and cathode are energized. Under the action of the electric field, the cathode buffer pool The ions begin to migrate and move into channel 7, react with the protein, and come into contact with the indicator, causing the indicator to change color. After the second set time, the power is turned off, and the electrophoresis is completed.

[0042] S05, taking a picture of the observation window 3 to obtain an image, and obtaining a length value of the color-changing area in the channel 7 according to the image; Specifically, the observation window 3 is photographed. Since the observation window 3 and the pressure cover 2 have different colors, the boundary between the target area and the non-target area in the image is obvious. The image after photographing is subjected to Canny edge detection and contour detection to determine the target area. The target area is the area inside the observation window 3 included in the image. Furthermore, the target area is subjected to affine transformation and masking to extract the MRB, and the migration distance of the MRB is obtained by contour detection. The MRB migration distance is the length value of the color-changing area in channel 7; Furthermore, since the size of the observation window 3, the size of the microfluidic chip 4, the size of the opening on the electrode PCB board 13, and the size of the channel 7 are all determined, the pixel points on the image can be read by taking a photo, and then the length value of the color change area in the channel 7 can be obtained by calculation; S06. Obtaining the protein content in the sample to be tested according to the length value and the standard relationship curve between the protein content and the MRB migration distance; Furthermore, the detection method also includes: A plurality of dairy products with known protein contents are used as samples to be tested, and the MRB migration distances corresponding to the dairy products with known protein contents are tested by a detection device; Using the MRB migration distance as the abscissa and the protein content of the dairy product with known protein content as the ordinate, a standard relationship curve between the protein content and the MRB migration distance is established; Furthermore, the protein content of the sample to be tested can be known according to the standard relationship curve and the length value obtained in step S05.

[0043] Working principle: When in use, first open the pressure cover 2, mix the sample to be detected, gel solution, background buffer and indicator to form a mixed solution, inject the mixed solution into the channel 7 through the anode buffer pool 5, then connect the control module 16 through the control terminal, press the start button, power on the detection device, and control the temperature control unit 9 through the control module 16 to make the microfluidic chip 4 reach the target temperature, and maintain the first set time to make the mixed solution turn into a solid state, thereby fixing the protein, and then inject the anode buffer and cathode buffer into the anode buffer pool 5 and the cathode buffer pool 6 respectively, cover the pressure cover 2, press the electrophoresis button, power on the electrode PCB board 13, thereby powering on the electrode 14, and under the action of the electric field, the cathode buffer in The ions begin to migrate and move into the channel 7, react with the protein, and come into contact with the indicator, the indicator changes color, and the power is automatically turned off after maintaining the second set time. At this time, the electrophoresis is completed, and then the camera button is pressed. The observation window 3 is photographed by the camera module to obtain an image, and then the calculation button is pressed. The length value of the color-changing area is obtained according to the image through the processing module, and the protein content of the sample to be tested is obtained according to the standard relationship curve and the length value, thereby obtaining the protein content of the dairy product with unknown protein content.

[0044] The above description is only a preferred embodiment of the present application and an explanation of the technical principles used. Those skilled in the art should understand that the scope of the invention involved in the present application is not limited to the technical solution formed by a specific combination of the above technical features, but should also cover other technical solutions formed by any combination of the above technical features or their equivalent features without departing from the inventive concept. For example, the above features are replaced with (but not limited to) technical features with similar functions disclosed in the present application.

Claims

1. A full-scene visual instant detection device for milk protein, characterized in that: include: A housing (1), wherein the top of the housing (1) is open, and a pressure cover (2) is movably provided at the opening, an observation window (3) is provided on the pressure cover (2), and the observation window (3) and the pressure cover (2) are of different colors; A microfluidic chip (4), the microfluidic chip (4) being arranged inside the housing (1), the top of the microfluidic chip (4) being provided with at least three detection parts, the detection parts being used to contain a mixed solution, the mixed solution comprising a sample to be detected, an indicator, a background buffer solution and a gel solution; The detection part comprises an anode buffer pool (5), a cathode buffer pool (6) and a channel (7), wherein the channel (7) is located between the anode buffer pool (5) and the cathode buffer pool (6), and two ends of the channel (7) are respectively connected to the anode buffer pool (5) and the cathode buffer pool (6), wherein the anode buffer pool (5) is a circular structure, and the cathode buffer pool (6) is a square structure; A constant temperature component, the constant temperature component is arranged inside the housing (1) and located at the bottom of the microfluidic chip (4), and a receiving groove (17) is provided on the constant temperature component for receiving the microfluidic chip (4); An electrophoresis component is arranged above the microfluidic chip (4) and is used to perform electrophoresis on the mixed solution in the detection section.

2. The full-scene visual instant detection device for milk protein according to claim 1, characterized in that: The constant temperature component comprises a heat conducting block (8), the top of the heat conducting block (8) is provided with the receiving groove (17) adapted to the microfluidic chip (4), the bottom of the heat conducting block (8) is provided with a temperature control unit (9) for heating or cooling the heat conducting block (8), the bottom of the temperature control unit (9) is provided with a heat dissipation block (10), and the bottom of the heat dissipation block (10) has a plurality of heat dissipation fins.

3. The full-scene visual instant detection device for milk protein according to claim 2, characterized in that: The inner wall of the housing (1) is fixedly connected to a mounting plate (11), which is located at the bottom of the heat sink (10), and a through hole is provided on the mounting plate (11) corresponding to the heat sink (10). The thermostatic assembly further comprises a heat sink (12), which is arranged at the bottom of the mounting plate (11) and is arranged corresponding to the through hole.

4. The full-scene visual instant detection device for milk protein according to claim 3 is characterized in that: The electrophoresis assembly comprises an electrode PCB (13), wherein the electrode PCB (13) is arranged at the bottom of the observation window (3), and an electrode (14) is arranged at the bottom of the electrode PCB (13), wherein the electrode comprises an anode corresponding to the anode buffer pool (5) and a cathode corresponding to the cathode buffer pool (6), and the electrode PCB (13) is also provided with a through opening corresponding to the microfluidic chip (4).

5. The full-scene visual instant detection device for milk protein according to claim 4, characterized in that: The inner wall of the housing (1) is provided with a power supply component (15), and the inner wall of the bottom of the housing (1) is provided with a control module (16); the control module (16) is electrically connected to the power supply component (15), and the control module (16) is electrically connected to the temperature control component (9) and the heat sink (12); the control module (16) has a relay, which is electrically connected to the electrode PCB board (13) and is used to control the time of electrophoresis.

6. The full-scene visual instant detection device for milk protein according to claim 4, characterized in that: Anode buffer is added to the anode buffer tank (5), and the anode buffer is and The cathode buffer tank (6) is added with a cathode buffer, and the cathode buffer is an alkaline solution having ions, the indicator contacts the The ions change color.

7. The full-scene visual instant detection device for milk protein according to claim 5, characterized in that: The detection device further comprises: a control terminal, the control terminal being electrically connected to the control module (16), the control terminal having a control panel, the control panel being provided with a start button, an electrophoresis button, a photo taking button and a calculation button; The start button is used to start the detection device, thereby energizing the detection device, and controlling the temperature control unit (9) to work through the control module (16), so that the microfluidic chip (4) reaches a target temperature and maintains the temperature for a first set time; The electrophoresis button is used to operate the control module (16) to energize the electrode PCB board (13), so that the electrode (14) is energized to perform electrophoresis on the mixed solution, and the electrode PCB board (13) is deenergized after a second set time period; The photographing button is used to operate the photographing module to take a photograph of the observation window (3) and obtain an image; The calculation button is used to operate the processing module to obtain the length value of the color change area in the channel (7).

8. A detection method, using the milk protein full-scene visual instant detection device according to any one of claims 1 to 7, characterized in that: The detection method comprises: S01, opening the pressure cover (2), mixing the sample to be detected, the indicator, the background buffer solution and the gel solution to form a mixed solution, and injecting the mixed solution into the channel (7) through the anode buffer pool (5); S02, powering on the detection device, and controlling the temperature control unit (9) through the control module (16) to heat the microfluidic chip (4) to a target temperature, and maintaining the temperature for a first set time; S03, injecting anode buffer and cathode buffer into the anode buffer tank (5) and cathode buffer tank (6) respectively, and covering them with a gland (2); S04, energizing the electrode PCB board (13) through the control module (16), so that the electrodes are energized to perform electrophoresis on the mixed solution, and the second set time is maintained; S05, photographing the observation window (3) to obtain an image, and obtaining a length value of the color-changing area in the channel (7) based on the image; S06. Obtaining the protein content in the sample to be detected according to the length value and the standard relationship curve between the protein content and the MRB migration distance.

9. A detection method according to claim 7, characterized in that: According to the length value of the color change area in the image acquisition channel (7), it includes: Determine the target area through Canny edge detection and contour detection; the target area is the area within the observation window (3) included in the image; Affine transformation is performed on the target area and MRB is extracted through masking. The migration distance of MRB is detected through contour detection, and the MRB migration distance is used as the length value of the color change area in the channel (7).

10. A detection method according to claim 8, characterized in that: The detection method further comprises: Using a plurality of bovine dairy products with known protein contents as samples to be tested, and using the detection device to detect the MRB migration distances corresponding to the plurality of bovine dairy products with known protein contents; A standard relationship curve between the protein content and the MRB migration distance was established by taking the MRB migration distance as the abscissa and the protein content of the dairy product with known protein content as the ordinate.

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