Preparation and spotting method of digital microfluidic chip with local hydrophilic area

Abstract

The invention discloses a method for preparing a digital microfluidic chip with a local hydrophilic area, comprising: setting the position of the local hydrophilic treatment area of ​​the upper cover according to the electrode position of the bottom plate of the digital microfluidic chip, making a blue film or a steel sheet, and cutting a plurality of holes in the blue film or the steel sheet; attaching the blue film or the steel sheet to the inner surface of the ITO glass upper cover with a Teflon super-hydrophobic layer in the digital microfluidic chip, and after attachment, each hole corresponds to the reaction area of ​​the electrode array in the bottom plate of the digital microfluidic chip one by one; plasma treatment is performed on the inner surface of the upper cover to change the hydrophilicity of the hole area, and after the plasma treatment, the blue film is torn off or the steel sheet is removed, and the hole area is chemically modified to form a local hydrophilic area; surface activation treatment is performed on the chemically modified surface, and after cleaning and drying, a digital microfluidic chip with a local hydrophilic area on the Teflon super-hydrophobic surface is obtained. A digital microfluidic chip spotting method with a local hydrophilic area is also disclosed.

Description

Technical Field

[0001] The invention relates to the technical field of digital microfluidic chips, and more specifically to a preparation method and a spotting method of a digital microfluidic chip with a local hydrophilic area. Background Art

[0002] Digital microfluidics uses electrodes to manipulate discrete droplets for directional driving, which is easy to operate. The cover of the digital microfluidics chip is generally made of ITO glass with a Teflon coating on the surface. Compared with the PDMS material used in traditional microfluidics, it is super hydrophobic. At present, when using the digital microfluidics chip for immunoassay, the capture protein is usually fixed on the surface of the cover. However, the super hydrophobicity of the cover will limit the effect of the reaction substance attachment, making it difficult to form long-term stable attachment, affecting the sensitivity of subsequent target detection. Summary of the invention

[0003] The technical problem to be solved by the present invention is to provide a method for preparing and spotting a digital microfluidic chip with a local hydrophilic area, so as to achieve long-term stable attachment of proteins, nucleic acids or cells and improve detection sensitivity.

[0004] In order to solve the above technical problems, according to one aspect of the present invention, a method for preparing a digital microfluidic chip having a local hydrophilic area is provided, comprising:

[0005] The position of the local hydrophilic treatment area of ​​the upper cover is set according to the electrode position of the bottom plate of the digital microfluidic chip, a blue film or a steel sheet is made, and a plurality of holes are cut in the blue film or the steel sheet corresponding to the position of the local hydrophilic treatment area;

[0006] The blue film or steel sheet is attached to the inner surface of the ITO glass upper cover with a Teflon super-hydrophobic layer in the digital microfluidic chip, and each hole of the blue film or steel sheet corresponds to a local hydrophilic treatment area and a reaction area of ​​the electrode array in the bottom plate of the digital microfluidic chip one by one after the attachment;

[0007] Plasma treatment is performed on the inner surface of the ITO glass upper cover with a blue film or a steel sheet attached thereto, so that a pre-hydrophilic surface is formed in the hole area, and after the plasma treatment, the blue film is torn off or the steel sheet is removed, and the hole area forming the pre-hydrophilic surface is chemically modified to form a local hydrophilic area;

[0008] The chemically modified surface is subjected to surface activation treatment to enable the local hydrophilic area to have the ability to stably attach proteins and / or DNA, and after cleaning and drying, a digital microfluidic chip with a Teflon super-hydrophobic surface and a local hydrophilic area is obtained.

[0009] Its further technical solution is: the size of the local hydrophilic area is 0.5mm 2 -1cm 2The contact angle of the Teflon super hydrophobic layer is greater than 110°, and the contact angle of the local hydrophilic area is 40-65°.

[0010] The further technical scheme is: the chemical modification of the hole area forming the pre-hydrophilic surface specifically includes: adding APTES with a concentration of 2%-5% to the hole area, and spotting at regular intervals, heating to milky white after white hydrolysis appears, cooling and then rinsing with cold water, and drying for use.

[0011] The further technical solution is: the step of heating to milky white specifically includes: placing the digital microfluidic chip on a 50°C hot stage, and after the alcohol in the local hydrophilic area evaporates, moving the chip to a 100°C hot stage and heating it to milky white.

[0012] The further technical scheme is: the surface activation treatment of the chemically modified surface specifically includes: using 10% glutaraldehyde to incubate the local hydrophilic area at 37° for 30 minutes to perform surface modification.

[0013] Its further technical solution is: setting the position of the local hydrophilic treatment area of ​​the upper cover according to the electrode position of the bottom plate of the digital microfluidic chip, making a blue film or a steel sheet, and before that also includes: taking an ITO glass slide for cleaning, then blowing off the moisture, high-temperature drying, spin coating Teflon after cooling, and baking to obtain an ITO glass upper cover with a Teflon super-hydrophobic layer as the upper cover of the digital microfluidic chip.

[0014] A further technical solution is: the spin coating of Teflon and baking specifically includes: spin coating of Teflon and then baking at temperatures of 40° C. and 180° C. in sequence.

[0015] A further technical solution is as follows: the shape of the local hydrophilic area is circular, rectangular, polygonal or irregular.

[0016] In order to solve the above technical problems, according to another aspect of the present invention, a method for spotting a digital microfluidic chip having a local hydrophilic area is provided, wherein the method for spotting a digital microfluidic chip having a local hydrophilic area is applied to a digital microfluidic chip prepared by the above method for preparing a digital microfluidic chip having a local hydrophilic area, comprising:

[0017] The optical positioning function of the spotter is used to scan and locate a corner of the ITO glass cover in the digital microfluidic chip. After scanning and positioning, the coordinates of the corner are used as the positioning origin. Each local hydrophilic area is moved and scanned according to the pre-stored coordinates of the local hydrophilic area in the ITO glass cover, and photos are taken for confirmation. After confirmation, the coordinates of the center position of each hydrophilic area are recorded to locate the local hydrophilic area.

[0018] The sample is spotted onto the local hydrophilic area after scanning and positioning by a spotter to form a plurality of sample arrays in the local hydrophilic area.

[0019] The further technical solution is: the digital microfluidic chip spotting method with a local hydrophilic area also includes:

[0020] The ITO glass cover of the spotted digital microfluidic chip was incubated in a high humidity environment of more than 70%, and after incubation, the local hydrophilic area was sealed with BSA, and then rinsed with PBST.

[0021] The beneficial technical effect of the present invention is that: compared with the prior art, the method for preparing a digital microfluidic chip with a local hydrophilic area of ​​the present invention sets the position of the local hydrophilic treatment area of ​​the upper cover according to the electrode position of the digital microfluidic chip bottom plate, manufactures a blue film or a steel sheet, and cuts a plurality of holes in the blue film or the steel sheet corresponding to the position of the local hydrophilic treatment area, and when the blue film or the steel sheet is attached to the inner surface of the super-hydrophobic ITO glass upper cover of the digital microfluidic chip, each hole is accurately positioned one by one with a local hydrophilic treatment area and the reaction area of ​​the electrode array in the bottom plate of the digital microfluidic chip, so as to ensure that the adsorbed droplets can be controlled in the subsequent detection experiment in the local hydrophilic area. , making the detection process controllable, and plasma treatment is performed on the inner surface of the ITO glass cover with a blue film or a steel sheet attached, so that a pre-hydrophilic surface is formed in the hole area, and the blue film is torn off or the steel sheet is removed after the plasma treatment, and the hole area forming the pre-hydrophilic surface is chemically modified to form a local hydrophilic area with hydrophilic properties, and then the chemically modified surface is subjected to surface activation treatment so that the local hydrophilic area has the ability to stably attach proteins and / or DNA, which is convenient for the subsequent use of the digital microfluidic chip for the detection of biological molecules such as immunoassays, and the efficient fixation of proteins can achieve long-term stable protein attachment and improve the detection sensitivity. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 It is a schematic flow chart of a specific embodiment of a method for preparing a digital microfluidic chip with a local hydrophilic area of ​​the present invention.

[0023] Figure 2 It is a schematic diagram of the exploded structure of the digital microfluidic chip of the present invention.

[0024] Figure 3 It is a schematic diagram of the positions of the electrode arrays on the bottom plate after the blue film is attached to the ITO glass upper cover in the method for preparing the digital microfluidic chip with a local hydrophilic area of ​​the present invention.

[0025] Figure 4 yes Figure 3 Magnified view of section A of the structure shown.

[0026] Figure 5It is a schematic flow chart of a method for spotting samples on a digital microfluidic chip with a local hydrophilic area provided in an embodiment of the present invention.

[0027] Figure 6 The present invention is a schematic diagram of the ITO glass cover in the digital microfluidic chip undergoing plasma treatment, chemical modification, surface activation and spotting. DETAILED DESCRIPTION

[0028] In order to enable those skilled in the art to more clearly understand the objectives, technical solutions and advantages of the present invention, the present invention is further described below in conjunction with the accompanying drawings and embodiments.

[0029] Reference Figure 1 , Figure 1 The figure is a flow chart of a specific embodiment of the method for preparing a digital microfluidic chip with a local hydrophilic area of ​​the present invention. In the embodiment shown in the figure, the method for preparing a digital microfluidic chip with a local hydrophilic area includes:

[0030] S101, take an ITO glass slide, clean it, blow off the water, spin-coat Teflon, and bake it to obtain an ITO glass cover with a Teflon super-hydrophobic layer as a cover of a digital microfluidic chip.

[0031] Specifically, in this step, a nitrogen gun can be used to blow away dust on the surface of the ITO glass slide, and then the ITO glass slide is ultrasonically cleaned 1-2 times with isopropyl alcohol, and then cleaned with pure water, and the surface moisture is blown away by the nitrogen gun, and baked at 180°C for 10 minutes. After cooling, a certain amount of Teflon is spin-coated to form a Teflon super-hydrophobic layer, and then baked at 40°C for 10 minutes and at 180°C for 20 minutes in turn to obtain an ITO glass cover with a Teflon super-hydrophobic layer as a cover of a digital microfluidic chip.

[0032] S102, setting the position of the local hydrophilic treatment area of ​​the upper cover according to the electrode position of the bottom plate of the digital microfluidic chip, making a blue film, and cutting a plurality of holes in the blue film corresponding to the position of the local hydrophilic treatment area.

[0033] In this embodiment, a blue film with good adhesion and cutting performance is used, and the size of the blue film is the same as that of the ITO glass cover. In some other embodiments, a steel sheet can be used instead of the blue film.

[0034] In the present invention, the position of the local hydrophilic treatment area can be designed according to the electrode position of the digital microfluidic chip, and a plurality of holes can be designed on the CAD according to the position of the local hydrophilic treatment area, and then introduced into a cutting machine to cut the blue film, wherein the shape and size of each hole can be different, and are usually slightly smaller than the size of an electrode.

[0035] S103, attaching the blue film to the inner surface of the ITO glass cover with a Teflon super-hydrophobic layer in the digital microfluidic chip, and after attachment, each hole of the blue film corresponds one-to-one to a local hydrophilic treatment area and a reaction area of ​​the electrode array in the bottom plate of the digital microfluidic chip.

[0036] In this step, the blue film is attached to the inner surface of the ITO glass cover with a Teflon super-hydrophobic layer in the digital microfluidic chip. When attaching, a cotton swab can be used to scrape and fit it flat. As is known to all, Figure 2 As shown, the digital microfluidic chip includes an upper cover 10 provided with a sampling hole 11 and a bottom plate 30 provided with an electrode array 31. The upper cover 10 and the bottom plate 30 are assembled together by a tape ring 20, and the tape ring allows the upper cover 10 to be assembled on the bottom plate 30 at a preset distance (e.g., 100 μm). When the blue film of the present invention is attached, the local hydrophilic area and the reaction area of ​​the electrode array 31 in the bottom plate 30 of the digital microfluidic chip are accurately positioned one by one, as shown in FIG. Figure 3 and Figure 4 As shown, in this embodiment, a local hydrophilic area 40 corresponds to an electrode position 32 to ensure that the adsorbed droplets can be controlled when a detection experiment is performed in the local hydrophilic area later, so that the detection process is controllable. Understandably, in order to more clearly show the relationship between the electrode positions 32 and the local hydrophilic areas 40 in the electrode array 31, the local hydrophilic areas 40 corresponding to some electrode positions 32 in the figure are not shown in the figure.

[0037] S104, plasma treatment is performed on the inner surface of the ITO glass cover with the blue film attached thereto, so that a pre-hydrophilic surface is formed in the hole area, and the blue film is torn off after the plasma treatment, and the hole area forming the pre-hydrophilic surface is chemically modified to form a local hydrophilic area.

[0038] In this step, the inner surface of the ITO glass cover with the blue film is treated with air (oxygen) plasma to change the surface properties. The position corresponding to the hole is temporarily hydrophilic, while the area covered by the blue film is still the Teflon super-hydrophobic surface. In order to prevent the reagents during chemical modification from penetrating into the blue film through the hole area that forms the pre-hydrophilic surface, thereby affecting the super-hydrophobicity of the Teflon-covered area, the blue film is quickly torn off after the plasma treatment and then the hole area is chemically modified.

[0039] In the present invention, the chemical modification of the hole area forming the pre-hydrophilic surface specifically includes: adding APTES (3-aminopropyltriethoxysilane) to the hole area, and spotting at regular intervals, after white hydrolysis appears, placing the ITO glass cover of the digital microfluidic chip on a 50°C hot stage, and after the alcohol in the local hydrophilic area evaporates, moving it to a 100°C hot stage and heating it to a milky white color, and cooling and drying; preferably, after heating to a milky white color and cooling, it can be rinsed with pure water, and then ultrasonically cleaned and dried.

[0040] In this embodiment, the concentration of APTES can be 2%-5%, and when adding the sample, the ITO glass cover can be covered with a culture dish to prevent it from drying too quickly and being exposed to air to cause hydrolysis, and the sample can be added vertically in batches and at regular intervals.

[0041] Understandably, the original Teflon surface will not be affected by chemical reagents, and only the holes treated with plasma will adhere to APTES and become hydrophilic. In some other embodiments, the reverse steam method can also be used for chemical modification, specifically including: injecting 2%-5% APTES into the culture dish, the solution culture dish is built into a bracket, the plasma-treated ITO glass inner cover is inverted on the bracket, the dish cover is covered, and the culture dish is placed on a 40-80°C hot plate for one hour. The APTES solution evaporates, and the APTES vapor is adsorbed to the upper cover containing iso-oxygen ions to react with it until the vapor forms water droplets on the surface of the glass slide, and the cooling and drying process can also be performed. Chemical modification can also be carried out in the local hydrophilic area to introduce appropriate functional groups to provide controllable active sites.

[0042] S105, performing surface activation treatment on the chemically modified surface so that the local hydrophilic area has the ability to stably attach proteins and / or DNA, and after cleaning and drying, obtaining a digital microfluidic chip with a Teflon super-hydrophobic surface and a local hydrophilic area.

[0043] In this step, the surface activation treatment of the chemically modified surface specifically includes: using 10% glutaraldehyde to incubate the local hydrophilic area at 37°C for 30 minutes to perform surface modification, and then rinsing with pure water and drying after surface modification, so that the local hydrophilic area has the ability to stably attach proteins and / or DNA. Glutaraldehyde can form some groups suitable for attaching proteins and DNA on the surface of the local hydrophilic area, so that the local hydrophilic area has the ability to stably attach proteins and / or DNA, and in the present invention, the contact angle of the local hydrophilic area after the hydrophilic treatment is 40-65°.

[0044] In this embodiment, the size of the local hydrophilic area can be 0.5 mm 2 -1cm 2 The shape can be circular, rectangular, polygonal or irregular, preferably circular.

[0045] As can be seen from the above, the present invention performs local hydrophilic treatment on the ITO glass cover with a Teflon super-hydrophobic layer, and the size of the hole can be designed to be smaller to form a local hydrophilic zone in a small area. During the hydrophilic treatment process, each hole of the blue film or the steel sheet is accurately positioned with a local hydrophilic treatment area and a reaction area of ​​the electrode array in the bottom plate of the digital microfluidic chip, which can ensure the controllability of the local hydrophilic area of ​​the small area in the subsequent detection experiment of the adsorption droplet operation, and the hole area with the blue film attached is plasma treated to form a pre-hydrophilic surface, and after the plasma treatment, the blue film is torn off or the steel sheet is removed, and the hole area forming the pre-hydrophilic surface is chemically modified to form a local hydrophilic area with hydrophilic properties, and then the surface after chemical modification is surface activated so that the local hydrophilic area has the ability to stably attach proteins and / or DNA, which is convenient for the subsequent use of the digital microfluidic chip for the detection of biological molecules such as immunoassays. Efficient fixation of proteins can achieve long-term stable attachment of proteins, nucleic acids or cells, and improves detection sensitivity.

[0046] Reference Figure 5 , Figure 5 The figure is a flow chart of a specific embodiment of the method for spotting a digital microfluidic chip with a local hydrophilic area of ​​the present invention. The method for spotting a digital microfluidic chip with a local hydrophilic area of ​​the present invention is applied to a digital microfluidic chip prepared by the method for preparing a digital microfluidic chip with a local hydrophilic area of ​​the above embodiment. In the embodiment shown in the figure, the method for spotting a digital microfluidic chip with a local hydrophilic area comprises:

[0047] S106. Use the optical positioning function of the spotter to scan and locate a corner of the ITO glass cover in the digital microfluidic chip. After scanning and positioning, use the coordinates of the corner as the positioning origin, move and scan each local hydrophilic area according to the pre-stored coordinates of the local hydrophilic area in the ITO glass cover, and take a photo for confirmation. After confirmation, record the coordinates of the center position of each hydrophilic area to locate the local hydrophilic area.

[0048] In this step, the spotter can be positioned by optical positioning using the corners of the ITO glass cover (upper right corner / lower right corner / upper left corner / lower left corner) and the injection hole, etc., to scan and search for the local hydrophilic area to locate the local hydrophilic area. The located local hydrophilic area can be used as the test area.

[0049] S107, spotting the sample onto the local hydrophilic area after scanning and positioning by a spotting instrument to form a plurality of sample arrays in the local hydrophilic area.

[0050] In this step, samples (such as protein or DNA solution) can be loaded into the test area in a customized form to form multiple sample arrays, that is, the spacing and arrangement of samples can be different when spotting. For example, a 6*6 sample array and a 3*3 sample array can be formed by spotting in a local hydrophilic area to set up a control group, etc. When spotting, the sample can be specifically or non-specifically covalently linked to the functional group formed after chemical modification to achieve fixation, thereby achieving efficient multi-point small area modification of samples.

[0051] It can be seen that the spotting method of the present invention can use a spotter to spot the same antibody on the surface of the same local hydrophilic area to conduct parallel repeated experiments, or spot different antibodies to broaden the diversity of test targets. It can also use the micro-droplet manipulation ability of the digital microfluidic chip to perform multiple immunoassays on extremely small amounts of scarce samples, such as infant fingertip blood.

[0052] Understandably, after the spotting is completed, the ITO glass cover can be incubated in a high humidity environment of more than 70%, and after incubation, the local hydrophilic area can be blocked with BSA, and then rinsed with PBST for subsequent immunoassay procedures.

[0053] In summary, the present invention performs local hydrophilic treatment on the ITO glass cover with Teflon super-hydrophobic layer, and the local hydrophilic area is small, so as to obtain a digital microfluidic core with a local hydrophilic area on the super-hydrophobic surface, and prepare a sample array by spotting on the local hydrophilic area, thus creating a multiple array immunotechnology platform, such as Figure 6 As shown, a blue film or a steel sheet is attached to the inner surface of the super-hydrophobic ITO glass upper cover of the digital microfluidic chip. After attachment, each hole and a local hydrophilic treatment area and the reaction area of ​​the electrode array in the bottom plate of the digital microfluidic chip are accurately positioned one by one, and the inner surface of the ITO glass upper cover attached with the blue film or the steel sheet is plasma treated to form a pre-hydrophilic surface in the hole area, and the blue film is torn off or the steel sheet is removed after the plasma treatment, and the hole area forming the pre-hydrophilic surface is chemically modified to form a local hydrophilic area with hydrophilic properties, and then the chemically modified surface is surface activated to enable the local hydrophilic area to have the ability to stably attach proteins and / or DNA, and then the sample is spotted on the local hydrophilic area to form as shown in the figure. Figure 6 The sample microarray shown can achieve efficient protein fixation and long-term stable attachment, thereby improving detection sensitivity.

[0054] The above description is only a preferred embodiment of the present invention, and does not limit the present invention in any form. Those skilled in the art can make various equivalent changes and improvements based on the above embodiments, and all equivalent changes or modifications made within the scope of the claims should fall within the protection scope of the present invention.

Claims

1. A method for preparing a digital microfluidic chip having a local hydrophilic area, characterized in that: The method for preparing a digital microfluidic chip having a local hydrophilic area comprises: The position of the local hydrophilic treatment area of ​​the upper cover is set according to the electrode position of the bottom plate of the digital microfluidic chip, a blue film or a steel sheet is made, and a plurality of holes are cut in the blue film or the steel sheet corresponding to the position of the local hydrophilic treatment area; The blue film or steel sheet is attached to the inner surface of the ITO glass upper cover with a Teflon super-hydrophobic layer in the digital microfluidic chip, and each hole of the blue film or steel sheet corresponds to a local hydrophilic treatment area and a reaction area of ​​the electrode array in the bottom plate of the digital microfluidic chip one by one after the attachment; Plasma treatment is performed on the inner surface of the ITO glass upper cover with a blue film or a steel sheet attached thereto, so that a pre-hydrophilic surface is formed in the hole area, and after the plasma treatment, the blue film is torn off or the steel sheet is removed, and the hole area forming the pre-hydrophilic surface is chemically modified to form a local hydrophilic area; The chemically modified surface is subjected to surface activation treatment to enable the local hydrophilic area to have the ability to stably attach proteins and / or DNA, and after cleaning and drying, a digital microfluidic chip with a Teflon super-hydrophobic surface and a local hydrophilic area is obtained.

2. The method for preparing a digital microfluidic chip having a local hydrophilic area according to claim 1, characterized in that: The size of the local hydrophilic area is 0.5 mm 2 -1cm 2 The contact angle of the Teflon super hydrophobic layer is greater than 110°, and the contact angle of the local hydrophilic area is 40-65°.

3. The method for preparing a digital microfluidic chip having a local hydrophilic area according to claim 1, characterized in that: The chemical modification of the hole area forming the pre-hydrophilic surface specifically includes: adding APTES with a concentration of 2%-5% to the hole area, and spotting at regular intervals, heating to milky white after white hydrolysis occurs, cooling, washing with pure water, and drying for use.

4. The method for preparing a digital microfluidic chip having a local hydrophilic area according to claim 3, characterized in that: The step of heating to a milky white color specifically comprises: placing the digital microfluidic chip on a 50° C. hot stage, and after the alcohol in the local hydrophilic area is partially evaporated, moving the chip to a 100° C. hot stage and heating it to a milky white color.

5. The method for preparing a digital microfluidic chip having a local hydrophilic area according to claim 1, characterized in that: The surface activation treatment of the chemically modified surface specifically includes: using 10% glutaraldehyde to incubate the local hydrophilic area at 37° for 30 minutes to perform surface modification.

6. The method for preparing a digital microfluidic chip having a local hydrophilic area according to claim 1, characterized in that: The position of the local hydrophilic treatment area of ​​the upper cover is set according to the electrode position of the bottom plate of the digital microfluidic chip, and a blue film or a steel sheet is made. Before that, the method also includes: taking an ITO glass slide for cleaning, then blowing off the moisture, high-temperature drying, spin-coating Teflon after cooling, and baking to obtain an ITO glass upper cover with a Teflon super-hydrophobic layer as the upper cover of the digital microfluidic chip.

7. The method for preparing a digital microfluidic chip having a local hydrophilic area according to claim 6, characterized in that: The spin coating of Teflon and baking specifically include: spin coating of Teflon and then baking at temperatures of 40° C. and 180° C. in sequence.

8. The method for preparing a digital microfluidic chip having a local hydrophilic area according to claim 1, characterized in that: The shape of the local hydrophilic area is circular, rectangular, polygonal or irregular.

9. A method for spotting samples on a digital microfluidic chip having a local hydrophilic region, characterized in that: Applied to a digital microfluidic chip prepared by the method for preparing a digital microfluidic chip having a local hydrophilic area according to any one of claims 1 to 8, the digital microfluidic chip spotting method having a local hydrophilic area comprises: The optical positioning function of the spotter is used to scan and locate a corner of the ITO glass cover in the digital microfluidic chip. After scanning and positioning, the coordinates of the corner are used as the positioning origin. Each local hydrophilic area is moved and scanned according to the pre-stored coordinates of the local hydrophilic area in the ITO glass cover, and photos are taken for confirmation. After confirmation, the coordinates of the center position of each hydrophilic area are recorded to locate the local hydrophilic area. The sample is spotted onto the local hydrophilic area after scanning and positioning by a spotter to form a plurality of sample arrays in the local hydrophilic area.

10. The method for spotting samples on a digital microfluidic chip having a local hydrophilic area according to claim 9, characterized in that: The digital microfluidic chip spotting method with a local hydrophilic area also includes: The ITO glass cover of the spotted digital microfluidic chip was incubated in a high humidity environment of more than 70%, and after incubation, the local hydrophilic area was sealed with BSA, and then rinsed with PBST.

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