A method for preparing a hydrophilic array based on a hydrophobic substrate

Abstract

This invention discloses a method for preparing a hydrophilic array based on a hydrophobic substrate, comprising the following steps: (1) covering a hydrophobic substrate with a mask having a plurality of holes evenly arranged; (2) depositing a solution or suspension of hydrophilic material into the holes on the mask; wherein the deposition method is ultrasonic atomization, spraying, or chemical vapor deposition; (3) during the deposition process, placing a movable mask on a porous mask, and changing the shielding area of ​​the movable mask by motor drive or manual movement to control the amount of hydrophilic material at different positions in the array; (4) removing the mask from the hydrophobic substrate, so that the hydrophilic material is deposited on the hydrophobic substrate to form a hydrophilic region array; this invention does not require complex process steps or equipment, and realizes efficient, controllable, and stable preparation of hydrophilic arrays.

Description

Technical Field

[0001] This invention relates to the field of substrate surface treatment technology, and more specifically to a method for preparing a hydrophilic array based on a hydrophobic substrate. Background Technology

[0002] A hydrophilic array on a hydrophobic substrate is a structure with unique surface properties, consisting of a series of hydrophilic regions distributed on the hydrophobic substrate. This structure can be used for droplet generation, whereby liquid is injected into the hydrophilic regions on the hydrophobic substrate, utilizing the surface tension of the liquid and the Rayleigh-Plateau instability to form stable droplets. Droplet generation is an important microfluidic technology with applications in various fields such as bioanalysis, chemical reactions, and materials synthesis.

[0003] There are two main methods for fabricating hydrophilic arrays on hydrophobic substrates: one is to modify the surface properties of the substrate through physical or chemical methods to give it different hydrophilicity or hydrophobicity; the other is to deposit hydrophilic substances on the hydrophobic substrate to form hydrophilic regions. The former usually requires complex process steps, such as etching, photolithography, and surface treatment; the latter is relatively simple, but has some problems, such as the selection of deposited materials, control of the deposition process, and post-deposition stability. In addition, how to reliably control the substances contained within the droplets and control the occurrence of reactions within the droplets are also important problems that droplet arrays need to solve. Summary of the Invention

[0004] Purpose of the invention: The purpose of this invention is to provide a method for preparing hydrophilic arrays based on hydrophobic substrates to solve the problems existing in the background technology and achieve efficient, controllable and stable preparation of hydrophilic arrays.

[0005] Technical solution: The present invention provides a method for preparing a hydrophilic array based on a hydrophobic substrate, comprising the following steps:

[0006] (1) Cover a hydrophobic substrate with a mask having a number of holes evenly arranged;

[0007] (2) Depositing a solution or suspension of a hydrophilic substance into the pores on the mask; wherein the deposition method is ultrasonic atomization, spraying, or chemical vapor deposition;

[0008] (3) During the deposition process, a movable mask is placed on a porous mask. The shielding area of ​​the movable mask is changed by motor drive and manual movement, so as to control the amount of hydrophilic material at different positions in the array.

[0009] (4) Remove the mask from the hydrophobic substrate, so that the hydrophilic material is deposited on the hydrophobic substrate to form an array of hydrophilic regions;

[0010] (5) Repeat steps (2) to (4) to deposit hydrophilic substances of different thicknesses at different locations or in different directions, or deposit different types of hydrophilic substances of different thicknesses at the same location, thereby obtaining hydrophilic arrays with different properties or functions.

[0011] Furthermore, in step (1), the holes in the mask are circular, square, triangular or other arbitrary shapes; the size of the holes is 0.1-5mm and the spacing is 0.2-10mm.

[0012] Furthermore, in step (1), the hydrophobic substrate is polydimethylsiloxane (PDMS), polypropylene (PP), polymethyl methacrylate (PMMA), or surface-modified glass, metal, or superhydrophobic material.

[0013] Furthermore, in step (1), the mask is a polymer, metal, or glass sheet that has been perforated, laser-engraved, or chemically etched.

[0014] Furthermore, in step (2), the hydrophilic substance is polyethylene glycol, polyvinylpyrrolidone, gelatin, agar, or a substance containing reagents.

[0015] The present invention discloses a method for droplet generation and reagent release based on a hydrophilic array on a hydrophobic substrate, comprising the following steps:

[0016] The hydrophilic array was placed in an aqueous liquid and then removed.

[0017] Passing aqueous liquids through the hydrophilic region;

[0018] After the droplets are generated, different phase liquids are poured onto the droplet array to prevent the droplets from evaporating in the air.

[0019] Furthermore, the hydrophilic region contains reagents, which can be released into the droplet during droplet formation, enabling reagent transfer or reaction.

[0020] Furthermore, a slowly dissolving substance is deposited on the reagent to achieve timed release of the reagent within the droplet.

[0021] Beneficial effects: Compared with the prior art, the present invention has the following significant advantages: It provides a simple, controllable and stable method for preparing hydrophilic arrays on hydrophobic substrates without the need for complex process steps or equipment; The present invention can be used in research in multiple fields such as bioanalysis, chemical reactions, and material synthesis. Attached Figure Description

[0022] Figure 1 This is a schematic diagram of the present invention;

[0023] Figure 2 This is a schematic diagram illustrating how the movable mask of the present invention enables quality control of hydrophilic materials at different locations;

[0024] Figure 3 This is a schematic diagram illustrating the functionalization of the hydrophilic region achieved through multiple depositions and the use of a movable mask, as described in this invention. Implementation

[0025] The technical solution of the present invention will be further described below with reference to the accompanying drawings. Example 1

[0026] like Figure 1 As shown, this embodiment of the invention provides a method for fabricating a hydrophilic array based on a hydrophobic substrate, comprising the following steps:

[0027] (S1) A PDMS substrate 2 with a thickness of 1 mm and a hydrophobic surface was prepared by casting method using polydimethylsiloxane (PDMS) as the substrate material;

[0028] (S2) A polyester film (mask) 1 with a number of holes evenly arranged is covered on a PDMS substrate; wherein the diameter of the holes is 200 μm and the spacing is 500 μm;

[0029] (S3) into the hole on the mask ( Figure 1 4) Along the direction of arrow, an aqueous solution containing 0.5% polyethylene glycol (PEG) and 0.01% fluorescein FITC is sprayed by ultrasonic atomization, causing PEG and FITC to deposit on the PDMS substrate, forming a hydrophilic region 3;

[0030] (S4) Remove the mask from the PDMS substrate to obtain a hydrophilic array 5 with fluorescence properties;

[0031] like Figure 2 As shown, Example 2

[0032] This invention provides a method for fabricating a hydrophilic array based on a hydrophobic substrate, comprising the following steps:

[0033] (S6) Using polydimethylsiloxane PDMS as the substrate material, a PDMS substrate with a thickness of 1 mm and a hydrophobic surface was prepared by molding method;

[0034] (S7) A polyester film (mask) with a number of holes evenly arranged is covered on a PDMS substrate; wherein the diameter of the holes is 200 μm and the spacing is 500 μm;

[0035] (S8) into the hole on the mask ( Figure 2 (In the direction of the arrow) An aqueous solution containing 0.5% polyethylene glycol (PEG) and 0.01% fluorescein FITC is sprayed by ultrasonic atomization, causing PEG and FITC to deposit on the PDMS substrate, forming a hydrophilic region;

[0036] (S9) Remove the mask from the PDMS substrate to obtain a hydrophilic array with fluorescence properties;

[0037] (S10) Repeat steps (S6) to (S9) to deposit hydrophilic materials of varying thicknesses at different locations, as detailed below:

[0038] After the first deposition, without removing the porous mask, a motor-driven movable mask 7 is added on top of the porous mask. The movable mask is controlled to slowly move away from the porous mask in the horizontal direction 7 at a fixed rate. At the same time, an ultrasonic atomization deposition is used to deposit a solution containing 0.5% polyvinylpyrrolidone (PVP) and 0.01% rhodamine B (RhB), so that PVP and RhB are deposited on the PDMS substrate, forming a PVP and RhB gradient in one direction, and obtaining a hydrophilic array 8 with a reagent content gradient.

[0039] like Figure 3 As shown, Example 3

[0040] This invention provides a method for fabricating a hydrophilic array based on a hydrophobic substrate, comprising the following steps:

[0041] (S11) Using polydimethylsiloxane PDMS as the substrate material, a PDMS substrate with a thickness of 1 mm and a hydrophobic surface was prepared by molding method;

[0042] (S12) A polyester film (mask) with a number of holes evenly arranged is covered on a PDMS substrate; wherein the diameter of the holes is 200 μm and the spacing is 500 μm;

[0043] (S13) into the hole on the mask ( Figure 3 (In the direction of the arrow) An aqueous solution containing 0.5% polyethylene glycol (PEG) and 0.01% fluorescein FITC is sprayed by ultrasonic atomization, causing PEG and FITC to deposit on the PDMS substrate, forming a hydrophilic region;

[0044] (S14) Remove the mask from the PDMS substrate to obtain a hydrophilic array with fluorescence properties;

[0045] (S15) Repeat steps (S11) to (S14) to deposit hydrophilic materials of varying thicknesses at different locations or in different directions, as detailed below:

[0046] After the first deposition, without removing the porous mask, a motor-driven movable mask 7 is added on top of the porous mask. The movable mask is slowly moved away from the porous mask at a fixed rate in the horizontal direction 9. Simultaneously, an ultrasonic atomization deposition of a solution containing 0.5% polyvinylpyrrolidone (PVP) and 0.01% rhodamine B (RhB) is performed, causing PVP and RhB to deposit on the PDMS substrate, forming a PVP-RhB gradient in one direction, which is the second deposition. After the second deposition, without removing the porous mask, the movable mask is again placed on top of the porous mask. In the direction perpendicular to the direction of movement of the movable mask during the second deposition 10, the movable mask is slowly moved away from the porous mask at a fixed rate. Simultaneously, an ultrasonic atomization deposition of a solution containing 0.5% gelatin and 0.01% enzyme-labeled antibody (ELISA) is performed, causing gelatin and ELISA to deposit on the PDMS substrate, forming a gelatin-ELISA gradient in another direction, which is the third deposition. In this way, hydrophilic arrays 11 with different properties or functions can be obtained. Example 4

[0047] Based on Example 3, after each reagent deposition, a layer of slow-dissolving gelatin or agar solution is further deposited on the reagent, or the gelatin or agar solution is added to the reagent deposited each time, in order to control the reagent release rate and release delay after droplet formation. Example 5

[0048] Droplet generation and reagent release were achieved using the hydrophilic arrays prepared in Examples 1-4. The hydrophilic arrays were placed in deionized water, cell culture medium, microbial culture medium, or PCR reagents and then removed, or these liquids were passed through the hydrophilic arrays to form droplet arrays. (e.g.) Figure 1 6). After droplet formation, reagents such as fluorescein, rhodamine B, and enzyme-labeled antibodies can be released into the droplets, thereby achieving reagent transfer or reaction. Differences in fluorescence signals or reaction results in droplets at different positions or directions can be observed using a fluorescence microscope. After droplet formation, the droplet array can be further placed in a flat-bottomed container, and paraffin oil or other immiscible phases can be poured onto the droplet array to prevent evaporation of the droplets in the air.

Claims

1. A method for fabricating a hydrophilic array based on a hydrophobic substrate, characterized in that, Includes the following steps: (1) A mask with a number of holes evenly arranged on a hydrophobic substrate; the holes of the mask are circular, square, triangular or other arbitrary shapes, the size of the holes is 0.1-5mm and the spacing is 0.2-10mm; the hydrophobic substrate is polydimethylsiloxane PDMS, polypropylene PP or surface-modified glass, metal or superhydrophobic material; the mask is a polymer, metal or glass sheet material processed by punching, laser engraving or chemical etching. (2) Deposit a solution or suspension of a hydrophilic substance into the pores on the mask; wherein the deposition method is ultrasonic atomization, spraying, or chemical vapor deposition; the hydrophilic substance is polyethylene glycol, polyvinylpyrrolidone, gelatin, agar, or a substance containing reagents; (3) During the deposition process, a movable mask is placed on a porous mask. The shielding area of ​​the movable mask is changed by motor drive and manual movement to control the amount of hydrophilic material at different positions in the array. (4) Remove the movable mask from the hydrophobic substrate so that the hydrophilic material is deposited on the hydrophobic substrate to form an array of hydrophilic regions; (5) Repeat steps (2) to (4) to deposit hydrophilic substances of different thicknesses at different locations or in different directions, or deposit different types of hydrophilic substances of different thicknesses at the same location, thereby obtaining hydrophilic arrays with different properties or functions.

2. The application of a hydrophilic array prepared by the method according to claim 1 in droplet generation and reagent release, characterized in that, Includes the following steps: The hydrophilic array is placed in an aqueous liquid and then removed, or the aqueous liquid is passed through the hydrophilic array. After the droplets are generated, they form a droplet array; Different phase liquids are poured onto a droplet array to prevent the droplets from evaporating in the air. The hydrophilic array contains reagents, which can be released into the droplets during droplet formation to achieve reagent transfer or reaction. Slow-dissolving substances are deposited on the reagents to achieve timed release of the reagents within the droplets.

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