A method for preparing an underwater bubble microreactor with site-specific reaction capability

Abstract

The application discloses a preparation method of an underwater bubble micro-reactor with a fixed-point reaction capability, and belongs to the field of underwater gas micro-reaction controller preparation methods. First, a laser marking machine is used to etch a hollow pattern on a pure zinc sheet as a mask, and the mask obtained through laser etching is attached to a substrate by double-sided adhesive tape. Then, polydimethylsiloxane, a curing agent and hydrophobic silicon dioxide are added to n-hexane and uniformly mixed to obtain a spraying liquid. The spraying liquid is sprayed onto the substrate covered with the mask. The sprayed substrate is placed in an oven for curing. After curing, the mask is removed, and an underwater bubble micro-reactor containing a gas-permeable pattern is obtained. The underwater bubble micro-reactor can achieve good control over underwater micro-reactions. The bubbles act as a protective "shell" to prevent the internal detection liquid drops from being polluted and evaporated. The laser etching and simple spraying technology can be combined to realize large-scale preparation and popularization.

Description

Technical Field

[0001] This invention relates to the field of underwater gas microreactor preparation methods, specifically to a method for preparing an underwater bubble microreactor with point-of-reaction capability. Background Technology

[0002] Droplets can be manipulated on surfaces to act as microreactors, simulating complex and large-scale facility environments to perform specific reactions and detections. This surface microfluidics technology offers numerous advantages, including rapid reaction speeds, small reagent volume, low cost, versatility, and high integration. In epidemiological investigations, analytical identification, and environmental simulation, the parallelization and miniaturization of platforms based on functional surface-based droplet precision detection technology are of great significance. A key technical challenge is obtaining an array of independent droplets that do not cross-contaminate while preventing rapid reagent loss due to droplet evaporation. Therefore, generating an array of independent and non-volatile capsule droplets becomes an effective strategy.

[0003] In existing technologies, a relatively effective solution reported so far involves utilizing the properties of superhydrophobic and superamphetophilic surfaces to fabricate patterned surfaces, where the droplet to be detected acts as the "core," while the outer oil droplets serve as a protective shell for the "core." This solution involves multiple fabrication steps, posing a significant cost challenge for large-scale production. Furthermore, because superhydrophobic surfaces require the construction of solid surfaces with extremely low surface energy to minimize the solid-liquid contact area, the micro- and nanostructures of superhydrophobic surfaces are very fragile and easily damaged, rendering them ineffective. Summary of the Invention

[0004] The purpose of this invention is to overcome the shortcomings of existing technologies and provide a method for preparing an underwater bubble microreactor with point-of-care reaction capability. This method not only enables the directional transport of underwater bubbles but also utilizes the superhydrophobic surface's superaerophilic properties underwater to inject an inert, clean gas as a protective "shell" for the droplets to be detected. The underwater bubble microreactor allows for excellent control of small underwater reactions (gas-gas merging, gas-liquid reactions), and the bubbles, acting as a protective "shell," prevent contamination and evaporation of the internal detection droplets. Combined with laser etching and simple spraying techniques, it can be mass-produced and widely adopted.

[0005] To achieve the above objectives, the present invention provides a method for preparing an underwater bubble microreactor with point-of-reaction capability, the method comprising the following steps:

[0006] S1. A laser marking machine is used to etch a hollow pattern on a pure zinc sheet as a mask, and the mask obtained by laser etching is attached to the substrate with double-sided adhesive.

[0007] S2. Add polydimethylsiloxane, curing agent and hydrophobic silica to n-hexane and mix evenly to obtain a spraying liquid;

[0008] S3. Spray the coating liquid onto the substrate covering the mask;

[0009] S4. Place the sprayed substrate in an oven for curing. After curing, remove the mask to obtain an underwater bubble microreactor containing an aerophilic pattern.

[0010] Preferably, in step S4, the aerobic pattern is a pattern formed by multiple circular regions, and one of the smallest circular regions is the delivery starting point, which is connected to other circular regions through a microfluidic channel.

[0011] Preferably, the diameter of the circular region is 1 to 10 mm.

[0012] Preferably, when the air-affinity pattern consists of two circular regions, the diameter of one circular region is 3mm and the diameter of the other circular region is 6mm; or, when the air-affinity pattern consists of three circular regions, the diameter of one circular region is 3mm and the diameter of the other two circular regions is 6mm; or, when the air-affinity pattern consists of four circular regions, the diameter of one circular region is 3mm and the diameter of the other three circular regions is 6mm.

[0013] Preferably, in step S4, when there are two circular regions in the aerobic pattern, the reactor with the mask removed is placed in water, and bubbles are injected into the circular region at the starting point of the transport. If the bubbles can be successfully transported to the circular region at the end point of the transport, it indicates that the underwater bubble microreactor has been successfully prepared. Alternatively, when there are more than two circular regions in the aerobic pattern, the reactor with the mask removed is placed in water, and bubbles are injected into one of the circular regions at the end point of the transport beforehand. Then, bubbles are injected into the circular region at the starting point of the transport. If the bubbles at the starting point of the transport will only be transported to the pre-injected bubble end point of the transport, it indicates that the underwater bubble microreactor has been successfully prepared.

[0014] Preferably, the thickness of the pure zinc sheet is 0.1 mm to 0.3 mm.

[0015] Preferably, the substrate is a glass slide or a metal sheet. The surface of the glass slide or metal sheet is flat, which facilitates the observation and manipulation of bubbles. The surface of the metal sheet needs to be highly hydrophilic and air-repellent in water.

[0016] Preferably, in step S4, the concentration of polydimethylsiloxane in the spraying liquid is 0.01–0.065 g / mL, the concentration of polydimethylsiloxane curing agent is 0.001–0.0065 g / mL, the concentration of hydrophobic silica is 0.01–0.05 g / mL, and the mass ratio of polydimethylsiloxane to polydimethylsiloxane curing agent is 10:1.

[0017] Preferably, in step S3, the spraying distance is 10-20cm and the number of spraying times is 3-5.

[0018] Preferably, in step S4, the curing temperature of the oven is 60-80 degrees Celsius and the curing time is 2-3 hours.

[0019] Preferably, the underwater bubble microreactor prepared by the method is used in droplet detection.

[0020] The beneficial effects of this invention are:

[0021] 1. This invention achieves directional transport of bubbles by controlling the different aerobic areas of two circular regions, resulting in a difference in surface energy between the two regions for a bubble of a certain volume.

[0022] 2. After verifying the behavior of bubbles only diffusing and not transporting in the multi-path gas-loving region along the direction of decreasing surface energy, this invention pre-defines a bubble as a protective gas chamber in the circular region at the desired reaction endpoint (with a larger gas-loving area and corresponding lower bubble surface energy), and adds reaction droplets inside. When a bubble is injected into the gas-loving region at the transport starting point (with a smaller gas-loving area than the endpoint gas-loving region and corresponding higher bubble surface energy), the bubble at the transport starting point will merge gas-gas with the pre-defined bubble region, thereby realizing the directional transport of bubbles and gas-liquid micro-reactions in complex systems. Attached Figure Description

[0023] Figure 1 A diagram recording the transport behavior of bubbles with two circular air-loving patterns.

[0024] Where a is the structural diagram of the air-loving pattern; b is the behavior record of bubbles in region 2; and c is the behavior record of bubbles in region 1.

[0025] Figure 2 A diagram recording the transport behavior of bubbles with three circular air-loving patterns.

[0026] Wherein, a is the structural diagram of the air-loving pattern; b is the record of bubble behavior in region 2 after bubbles are injected into region 1; c is the record of bubble behavior in region 1 after bubbles are injected into region 1; d is the record of bubble behavior in region 3 after bubbles are injected into region 1.

[0027] Figure 3 Scanning electron microscopy nanomaps of gas-loving patterns that enable the directional transport of bubbles in the direction of decreasing surface energy.

[0028] In this image, a is a scanning electron microscope image with a resolution of 20 μm, and the upper right corner of a shows the water contact angle of the anaerobic coating, which is ~152°. b is a scanning electron microscope image with a resolution of 4 μm, and the upper right corner of b is a magnified image with a resolution of 400 nm.

[0029] Figure 4 A diagram recording the transport behavior of bubbles with three circular air-loving patterns.

[0030] Wherein, a is the structural diagram of the air-loving pattern; b is the record of bubble behavior in the three regions after bubbles were injected into region 3 in advance; c is the record of bubble behavior in the three regions after bubbles were added to region 1 15 minutes after bubbles were added to region 3 in advance.

[0031] Figure 5 Low-magnification scanning electron microscope images of aerophilic surfaces corresponding to different bubble behaviors.

[0032] Figure 6 A diagram recording the transport behavior of bubbles with four circular air-loving patterns.

[0033] Wherein, a is the structural diagram of the air-loving pattern; b is the behavior record of the bubbles in region 1; c is the behavior record of the bubbles in region 2; c is the behavior record of the bubbles in region 3; d is the behavior record of the bubbles in region 4.

[0034] Figure 7 This is a diagram illustrating the bubble transport behavior with four circular aerophilic patterns and an implementation of gas-liquid microreactions on an aerophilic patterned surface.

[0035] Wherein, a is the structural diagram of the air-loving pattern; b is the behavior record of the bubbles in region 4; c is the behavior record of region 2; and d is the behavior record of the bubbles in region 3. Detailed Implementation

[0036] To make the technical problems, technical solutions, and beneficial effects to be solved by this application clearer, the following detailed description is provided in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative and are not intended to limit the scope of this application.

[0037] It should be noted that when a component is referred to as being "fixed to" or "set on" another component, it can be directly on or indirectly on that other component. When a component is referred to as being "connected to" another component, it can be directly connected to or indirectly connected to that other component.

[0038] It should be understood that the terms "length", "width", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this application.

[0039] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of this application, "multiple" means two or more, unless otherwise explicitly specified.

[0040] References to "one embodiment" or "some embodiments" as described in this specification mean that one or more embodiments of this application include a specific feature, structure, or characteristic described in connection with that embodiment. Therefore, the phrases "in one embodiment," "in some embodiments," "in other embodiments," "in still other embodiments," etc., appearing in different parts of this specification do not necessarily refer to the same embodiment, but rather mean "one or more, but not all, embodiments," unless otherwise specifically emphasized. The terms "comprising," "including," "having," and variations thereof mean "including but not limited to," unless otherwise specifically emphasized.

[0041] The present invention will be further described below with reference to the accompanying drawings and specific embodiments.

[0042] Example 1

[0043] This embodiment provides a method for preparing an underwater bubble microreactor with point-of-reaction capability. The preparation steps are as follows:

[0044] S1. A laser marking machine is used to etch a hollow pattern on a 0.2mm thick pure zinc sheet as a mask. The laser marking machine has a power of 20W, a frequency of 50Hz, and an etching time of 2 hours. The mask obtained by laser etching is then attached to a smooth glass substrate with double-sided adhesive.

[0045] S2. Add 1.4g of polydimethylsiloxane, 0.14g of curing agent and 0.8g of hydrophobic silica to 20ml of n-hexane and mix evenly to obtain the spraying liquid;

[0046] S3. Apply the coating liquid to the substrate covering the mask using a spray gun. The spray gun should be 15cm away and the number of sprays should be 4.

[0047] S4. Place the sprayed substrate in an oven for curing. Adjust the oven temperature to 80 degrees Celsius and wait three hours for curing to complete. After curing, remove the mask to obtain an underwater bubble microreactor containing an aerophilic pattern. The aerophilic pattern consists of two circular regions, one with a diameter of 3 mm and the other with a diameter of 6 mm. The 3 mm diameter circular region is used as the starting point for the transport and is connected to the 6 mm diameter circular region. The 3 mm diameter circular region is named Region 1, and the 6 mm diameter circular region is named Region 2.

[0048] The underwater bubble microreactor with point-of-reaction capability completed in this embodiment was subjected to bubble transport test.

[0049] Behavioral recording diagram of bubble transport test as follows Figure 1 As shown, when bubbles are injected into region 1, they can only diffuse into region 2 after fifteen minutes, but no further accumulation occurs. Then, when bubbles are added to region 2, the bubbles in region 1 begin to merge with those in region 2. We call this phenomenon, where bubbles that could only adhere to small aerophilic regions and could not undergo self-driven transport to larger aerophilic regions begin to merge with the added bubble after it is added to a larger aerophilic region, the "induction effect." Figure 1 In the diagram, 'a' represents a schematic diagram of the aerophilic pattern, 'b' represents a record of bubble behavior in region 2, and 'c' represents a record of bubble behavior in region 1. To characterize the relationship between microstructure and inductive effect, the microstructure of the aerophilic coating in region 2 was characterized at low magnification using scanning electron microscopy. Figure 5As shown in Figure b, scanning electron microscopy reveals micron-sized defects with an average diameter of 14 μm on the layer. The process of self-driven directional transport of bubbles can be described as follows: upon contact with the galvanic region, the bubble diffuses throughout the region, subsequently tending to form a continuous and complete gas film in the larger galvanic region. Further transport and accumulation on this gas film reduces surface energy. This reduction in surface energy is crucial for self-driven transport. However, the formation of a complete gas film from the diffused gas in the larger galvanic region requires overcoming a certain energy barrier, especially when micron-sized defects exist in the galvanic region. Compared to diffusion, transport, and accumulation, bubbles tend to merge with other bubbles. The energy barrier required for gas-gas merging is significantly lower than that required to form a complete gas film. Therefore, the energy difference allows bubbles that initially could not transport to begin transporting after the addition of bubbles in the endpoint region. The presence of defects increases the energy barrier required for the formation of a continuous gas film within the galvanic region. The inability of bubbles in region 1 to self-drive transport and accumulation into region 2 indicates that the gas diffusing into region 2 cannot overcome the high energy barrier caused by the defects.

[0050] Example 2

[0051] This embodiment provides a method for preparing an underwater bubble microreactor with point-of-reaction capability. The preparation steps are as follows:

[0052] S1. A laser marking machine is used to etch a hollow pattern on a 0.2mm thick pure zinc sheet as a mask. The laser marking machine has a power of 20W, a frequency of 50Hz, and an etching time of 2 hours. The mask obtained by laser etching is then attached to a smooth glass substrate with double-sided adhesive.

[0053] S2. Add 1.4g of polydimethylsiloxane, 0.14g of curing agent and 0.8g of hydrophobic silica to 20ml of n-hexane and mix evenly to obtain the spraying liquid;

[0054] S3. Apply the coating liquid to the substrate covering the mask using a spray gun. The spray gun should be 15cm away and the number of sprays should be 4.

[0055] S4. Place the sprayed substrate in an oven for curing. Adjust the oven temperature to 80 degrees Celsius and wait three hours for curing to complete. After curing, remove the mask to obtain an underwater bubble microreactor containing an aerophilic pattern. The aerophilic pattern consists of three circular regions. One circular region has a diameter of 3 mm, and the other two circular regions have a diameter of 6 mm. The 3 mm diameter circular region is used as the starting point for the transport and is connected to the other two 6 mm diameter circular regions. The 3 mm diameter circular region is named Region 1, and the other two 6 mm diameter circular regions are named Region 2 and Region 3, respectively.

[0056] The underwater bubble microreactor with point-of-reaction capability completed in this embodiment was subjected to bubble transport test.

[0057] Behavioral recording diagram of bubble transport test as follows Figure 2 As shown, a is a schematic diagram of the gas affinity pattern. Bubbles are injected into gas affinity region 1. b shows the bubble behavior in gas affinity region 2, c shows the bubble behavior in gas affinity region 1, and d shows the bubble behavior in gas affinity region 3. After the bubbles are injected into gas affinity region 1, they diffuse, transport, and accumulate in regions 2 and 3. After ten minutes, regions 2 (iv in b) and 3 (iv in d) both contain gas transported from region 1, while only a small amount of gas remains in region 1 (iv in c).

[0058] The microstructure of region 2 in the aerophilic pattern of the example was observed using a scanning electron microscope, and it was found that its microstructure is a typical micro / nano structure. For example... Figure 3 As shown, Figure a has a resolution of 20 μm, and the water contact angle of the anaerobic coating in the upper right corner is ~152°, achieving superhydrophobic properties. Figure b has a resolution of 4 μm, and the magnified image in the upper right corner has a resolution of 400 nm.

[0059] Example 3

[0060] This embodiment is identical to the method for preparing the underwater bubble microreactor with site-directed reaction capability in Embodiment 2. The difference lies in the bubble transport test steps for the underwater bubble microreactor with site-directed reaction capability. The behavior recording diagram of the bubble transport test is shown below. Figure 4 As shown, a is a schematic diagram of the aerophilic pattern. b is a record of bubble behavior in the three regions after adding bubbles to region 1 fifteen minutes after adding bubbles to region 3. Bubbles were initially injected into region 3, with an initial maximum height of h (v in b). After fifteen minutes, the bubbles diffused only into regions 1 and 2, but no further volumetric transport occurred (ii and iv in b). When bubbles were injected into region 1, they transported only into region 3 and merged with the pre-added bubbles (iii in c), while no bubbles accumulated in region 2 (i in c). This demonstrates that the energy barrier required to form a continuous gas film after the bubbles diffuse from region 1 to region 2 is greater than the energy barrier required to merge with the pre-added bubbles in region 3, thus controlling the direction of bubble transport. In other words, the "inductive effect" can be used to successfully achieve directional bubble transport. To characterize the relationship between the microstructure and the success of the inductive effect, the aerophilic coating on region 2 was characterized at low magnification using electron microscopy, as shown in the figure. Figure 5As shown in region a, electron microscopy reveals defects with an average diameter of 10 μm on the layer. The presence of these defects indicates that a considerable energy barrier needs to be overcome for bubbles diffusing from region 1 to region 2 to form a continuous gas film. These defects are less than 14 μm in diameter, and when bubbles are only introduced into region 1, they can form a continuous gas film and undergo self-driven transport. However, when a bubble is pre-given in region 3, the energy required to merge with it is lower, therefore the bubbles tend to merge with the pre-given bubble in region 3 first.

[0061] Example 4

[0062] This embodiment provides a method for preparing an underwater bubble microreactor with point-of-reaction capability. The preparation steps are as follows:

[0063] S1. A laser marking machine is used to etch a hollow pattern on a 0.2mm thick pure zinc sheet as a mask. The laser marking machine has a power of 20W, a frequency of 50Hz, and an etching time of 2 hours. The mask obtained by laser etching is then attached to a smooth glass substrate with double-sided adhesive.

[0064] S2. Add 1.4g of polydimethylsiloxane, 0.14g of curing agent and 0.8g of hydrophobic silica to 20ml of n-hexane and mix evenly to obtain the spraying liquid;

[0065] S3. Apply the coating liquid to the substrate covering the mask using a spray gun. The spray gun should be 15cm away and the number of sprays should be 4.

[0066] S4. Place the sprayed substrate in an oven for curing. Adjust the oven temperature to 80 degrees Celsius and wait three hours for curing to complete. After curing, remove the mask to obtain an underwater bubble microreactor containing an aerophilic pattern. The aerophilic pattern consists of four circular regions, one with a diameter of 3 mm and the other three with a diameter of 6 mm. The 3 mm diameter region is used as the starting point for the transport, connecting with the other three 6 mm diameter regions. The 3 mm diameter region is named Region 1, and the other three 6 mm diameter regions are named Region 2, Region 3, and Region 4, respectively. For experimental comparison, Regions 2, 3, and 4 are also interconnected.

[0067] The underwater bubble microreactor with point-of-reaction capability completed in this embodiment was subjected to bubble transport testing. For example... Figure 6As shown, a is a schematic diagram of the gas affinity pattern; b is a record of bubble behavior in region 1 after bubble injection in region 2 for ten minutes; c is a record of bubble behavior in region 2 after bubble injection in region 2 for ten minutes; d is a record of bubble behavior in region 3 after bubble injection in region 1 for ten minutes; e is a record of bubble behavior in region 4 after bubble injection in region 2 for ten minutes. When bubble is injected into region 2, the initial maximum bubble height (0 min) is h (Figure i in c). After ten minutes, the bubble diffuses only into regions 1, 3, and 4, but no further volumetric transport occurs (Figures ii in b, ii in d, and ii in e). When bubble is injected into region 1, the bubble is transported only into region 2 and merges with the pre-injected bubble (Figure iii in c), while no bubbles accumulate in regions 3 and 4 (Figures iii in d and iii in e). This demonstrates that the directional transport of bubbles using the "induction effect" is successfully achieved.

[0068] Example 5

[0069] This embodiment is exactly the same as the method for preparing the underwater bubble microreactor with point-of-reaction capability in Embodiment 4. The difference lies in the steps for testing bubble transport in the underwater bubble microreactor with point-of-reaction capability. Figure 7 As shown

[0070] A colored droplet of sodium hydroxide containing phenolphthalein was added to the bubbles in the pre-existing aerobic region. Then, carbon dioxide bubbles were injected into region 1. After the bubbles merged with the pre-existing bubbles, the alkaline droplets in the bubbles underwent a chemical reaction, causing the pH to rise and the color to change from red to colorless.

[0071] like Figure 7In diagram a), three large aerophilic circles with a diameter of 6 mm are named Region 2, Region 3, and Region 4, respectively, and the smaller aerophilic circle is named Region 1. Diagram b shows the behavior of bubbles in Region 4 and the subsequent injection of bubbles into Region 1, as well as the color change of the colored droplets. Diagram c shows the behavior of bubbles in Region 2 and the subsequent injection of bubbles into Region 1, as well as the color change of the colored droplets. Diagram d shows the behavior of bubbles in Region 3 and the subsequent injection of bubbles into Region 1, as well as the color change of the colored droplets. A certain volume of air is first injected into the large aerophilic region to form a large air drum (as shown in diagram i in b) as the reaction chamber. Then, a certain volume of sodium hydroxide droplets containing phenolphthalein is injected into the drum (as shown in diagram ii in b). At this time, the droplets turn purple due to the alkalinity of the droplets. When carbon dioxide bubbles are injected into Region 1 (as shown in diagram iii in b), the bubbles are directed towards the bubbles in Region 4 and merge (as shown in diagrams iv and v in b), that is, they enter the reaction chamber. By repeatedly injecting carbon dioxide bubbles, the acidic bubbles continuously merge with the bubbles in region 4, causing the droplets in the gas chamber to gradually change from purple to transparent (as in vi in ​​b). The decolorization of phenolphthalein is caused by a decrease in pH, indicating that the acidic gas reacts with the alkaline solution (2NaOH + CO2 → Na2CO3 + H2O). Similarly, in region 2 ( Figure 7 c) and 3 ( Figure 7 In region d), bubbles were also injected as gas chambers and manipulated in the same way as in region 4. It was found that the same gas-gas merging and droplet color development reactions occurred after carbon dioxide bubbles were injected in region 1. This indicates that an underwater bubble microreactor with site-directed reaction capability was successfully prepared by utilizing the "induction effect".

[0072] The bubble microreactor prepared in this invention shares the same advantages as microfluidics technology, integrating pretreatment, reaction, and detection functions into a single small chip. By designing microchannels and microstructures on the chip, precise control of trace fluids can be achieved, realizing the integration of the detection process. The size of the microchannels ranges from micrometers to millimeters, and the size of the microstructures is designed at the micro / nano level. This reduces the amount of experimental reagents used and offers advantages such as low cost, high automation, and ease of operation, showing broad application prospects in biomedicine and detection fields.

[0073] The above-described embodiments are only used to illustrate the technical solutions of this application, and are not intended to limit them. Although this application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of this application, and should all be included within the protection scope of this application.

Claims

1. A method for preparing an underwater bubble microreactor with point-of-reaction capability, characterized in that: The method includes the following steps: S1. A laser marking machine is used to etch a hollow pattern on a pure zinc sheet as a mask, and the mask obtained by laser etching is attached to the substrate with double-sided adhesive. S2. Add polydimethylsiloxane, curing agent and hydrophobic silica to n-hexane and mix evenly to obtain a spraying liquid; S3. Spray the coating liquid onto the substrate covering the mask; S4. Place the sprayed substrate in an oven for curing. After curing, remove the mask to obtain an underwater bubble microreactor with an aerophilic pattern. The aerophilic pattern is a pattern formed by multiple circular areas, and one of the smallest circular areas is the delivery starting point, which is connected to other circular areas through a microfluidic channel.

2. The method for preparing an underwater bubble microreactor with point-of-reaction capability according to claim 1, characterized in that: The diameter of the circular region is 1 to 10 mm.

3. The method for preparing an underwater bubble microreactor with point-of-reaction capability according to claim 2, characterized in that: When the aerobic pattern consists of two circular regions, the diameter of one circular region is 3 mm and the diameter of the other circular region is 6 mm. Alternatively, when the aerobic pattern consists of three circular regions, one circular region has a diameter of 3 mm, and the other two circular regions have a diameter of 6 mm. Alternatively, when the aerobic pattern consists of four circular regions, one circular region has a diameter of 3 mm, and the other three circular regions have a diameter of 6 mm.

4. The method for preparing an underwater bubble microreactor with point-of-reaction capability according to claim 1, characterized in that: In step S4, when there are two circular regions in the gas-loving pattern, the reactor with the mask removed is placed in water, and bubbles are injected into the circular region at the starting point of the transport. If the bubbles can be successfully transported to the circular region at the end point of the transport, it indicates that the underwater bubble microreactor has been successfully prepared. Alternatively, when there are more than two circular regions in the gas-absorbing pattern, the reactor with the mask removed is placed in water, and bubbles are pre-injected into the circular region at one of the delivery endpoints. Then, bubbles are injected into the circular region at the delivery starting point. The bubbles at the delivery starting point will only be transported to the delivery endpoint where bubbles were pre-injected, indicating that the underwater bubble microreactor has been successfully prepared.

5. The method for preparing an underwater bubble microreactor with point-of-reaction capability according to claim 1, characterized in that: The thickness of the pure zinc sheet is 0.1 mm to 0.3 mm; the substrate is a glass sheet or a metal sheet.

6. The method for preparing an underwater bubble microreactor with point-of-reaction capability according to claim 1, characterized in that: In step S4, the concentration of polydimethylsiloxane in the spraying liquid is 0.01~0.065 g / mL, the concentration of polydimethylsiloxane curing agent is 0.001~0.0065 g / mL, the concentration of hydrophobic silica is 0.01~0.05 g / mL, and the mass ratio of polydimethylsiloxane to polydimethylsiloxane curing agent is 10:

1.

7. The method for preparing an underwater bubble microreactor with point-of-reaction capability according to claim 1, characterized in that: In step S3, the spraying distance is 10-20 cm and the number of spraying times is 3-5.

8. The method for preparing an underwater bubble microreactor with point-of-reaction capability according to claim 1, characterized in that: In step S4, the curing temperature of the oven is 60-80 degrees Celsius and the curing time is 2-3 hours.

9. The application of an underwater bubble microreactor prepared by the method of claim 1 in droplet detection.

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