Method for grafting modification on surface of substrate

Abstract

The invention provides a method for graft modification on the surface of a substrate, which comprises the following steps: pretreating the surface of the substrate to connect hydroxyl, amino or sulfydryl on the surface of the substrate; placing the pretreated substrate in a silane coupling agent containing two silicon atoms or a mixed solution of the silane coupling agent containing two silicon atoms and the silane coupling agent containing one silicon atom for reaction; according to the preparation method, the silane coupling agent containing two silicon atoms is adopted independently or is mixed with the silane coupling agent containing one silicon atom, and then covalent bonding is carried out on the silane coupling agent and the surface of the substrate; the silane coupling agent containing two silicon atoms or a mixed solution of the silane coupling agent has unique advantages and higher reaction activity, has two sites capable of reacting with the surface of the substrate and rapidly reacts with active groups on the surface of the substrate to ensure effective surface modification, and the durability of a modification layer is improved through additional bonding points; the obtained substrate has better hydrolysis resistance.

Description

Technical Field

[0001] The present invention belongs to the technical field of functional material preparation, and particularly relates to a method for grafting and modifying a substrate surface. Background Art

[0002] As a cheap and easily available material, glass is an important experimental material due to its physical and chemical properties such as optical transparency, dimensional stability, chemical inertness, and low autofluorescence. The glass surface is commonly used as a support for biomolecules and is widely used in high-throughput analysis, such as gene chips, cell sequencing, DNA arrays, gene expression analysis, etc. The chemical versatility of silanes enhances the ideal properties of glass and provides an effective method for derivatizing various functional groups from the glass surface, realizing the functionalization of the glass surface. Through the derivatization of these functional groups, better surface properties can be created, including providing reactive groups suitable for immobilizing biomacromolecules and reactive groups suitable for in-situ chemical peptide or nucleic acid synthesis. In addition, silane modification can also be used to regulate the hydrophilicity and hydrophobicity of the surface, or provide antifouling properties that can reduce the non-specific adsorption of biomolecules to the surface, as well as antibacterial properties, superconducting properties, and antistatic properties. Silane surface modification is an important method for improving or changing the properties of glass substrates and is widely applied in various aspects such as biotechnology, medical devices, transportation, and building materials. However, the main disadvantage of silane-functionalized glass is the hydrolysis instability of the siloxane bond with the hydroxyl groups on the glass surface. Therefore, it is very important to maintain the effectiveness and stability of the modified surface. Summary of the Invention

[0003] The purpose of the present invention is to provide a more stable method for grafting and modifying a substrate surface, and the technical solutions provided are as follows:

[0004] A method for grafting and modifying a substrate surface, comprising the following steps:

[0005] Pretreat the surface of the substrate material to connect hydroxyl groups, amino groups, or mercapto groups on the surface of the substrate material to obtain a pretreated substrate; then place the pretreated substrate in a silane coupling agent containing two silicon atoms, or place the pretreated substrate in a mixed solution of a silane coupling agent containing two silicon atoms and a silane coupling agent containing one silicon atom for reaction.

[0006] According to an embodiment of the present invention, the substrate material may be a glass slide, a silicon wafer, PDMS, an aluminum sheet, etc.

[0007] According to an embodiment of the present invention, the pretreatment includes: ozone cleaning the substrate material under ultraviolet light, soaking it in a piranha solution, or oxygen plasma treatment.

[0008] According to an embodiment of the present invention, during the pretreatment process, it can also be controlled by a mask plate to make the obtained substrate in a dot matrix structure, so that a partial surface of the substrate is activated.

[0009] According to an embodiment of the present invention, the concentration of the solution or mixed solution of the silane coupling agent is 1-15 wt%, such as 2-10, such as 3-5 wt%. The solvent used in the silane coupling agent solution is selected from pure solvents such as methanol, ethanol, cyclohexane, toluene, acetone or a mixed solution thereof with water (99:1-90:10 v:v).

[0010] According to an embodiment of the present invention, when using a silane coupling agent containing two silicon atoms and a silane coupling agent containing one silicon atom, the mass ratio of the silane coupling agent containing one silicon atom to the silane coupling agent containing two silicon atoms is 1:1-10:1, such as 1:1-5:1.

[0011] According to an embodiment of the present invention, the silane coupling agent containing one silicon atom provides appropriate functionality for the substrate, such as amino, epoxy, aldehyde, carboxyl, etc., and the silane coupling agent containing two silicon atoms provides better stability and durability for the modified layer.

[0012] According to an embodiment of the present invention, the silane coupling agent containing one silicon atom is selected from 3-aminopropyltriethoxysilane, 3-aminopropyltrimethoxysilane, γ-glycidoxypropyltrimethoxysilane, vinyltrimethoxysilane, n-octyltrimethoxysilane or n-decyltrimethoxysilane.

[0013] According to an embodiment of the present invention, the silane coupling agent containing two silicon atoms is selected from bis(3-(trimethoxysilyl)propyl)amine, bis(triethoxysilyl)methane, bis(triethoxysilyl)ethane, vinylhexaethoxysilane or 1,8-bis(trimethoxysilyl)octane.

[0014] According to an embodiment of the present invention, the pH of the solution of the silane coupling agent containing two silicon atoms, or its mixed solution with the silane coupling agent containing one silicon atom is 3-5, such as 4.

[0015] According to an embodiment of the present invention, the temperature at which the pretreated substrate material reacts with the solution or mixed solution of the silane coupling agent is 0-40 °C, such as 5-30 °C.

[0016] According to an embodiment of the present invention, the method is a liquid phase grafting method.

[0017] According to an embodiment of the present invention, after the substrate reacts in the silane coupling agent containing two silicon atoms, or a mixed solution of the silane coupling agent containing two silicon atoms and the silane coupling agent containing one silicon atom, it further includes the steps of ultrasonic cleaning with absolute ethanol and deionized water, and then drying.

[0018] The present invention also provides a substrate prepared by the method as described above.

[0019] The present invention also provides the use of the substrate as described above in analysis and detection.

[0020] Beneficial effects

[0021] In the present invention, a silane coupling agent containing two silicon atoms alone or a mixture thereof with a silane coupling agent containing one silicon atom is used for covalent bonding with the substrate surface. Compared with only using a silane coupling agent containing one silicon atom, the silane coupling agent containing two silicon atoms or its mixed solution has unique advantages and higher reactivity. It has two sites that can react with the substrate surface, and the rapid reaction with the active groups on the substrate surface ensures effective surface modification. The additional bonding points improve the durability of the modified layer, and the obtained substrate has better hydrolysis resistance. In addition, the concentration of the silane coupling agent containing two silicon atoms or its mixed solution with a silane coupling agent containing one silicon atom has a great influence on the performance of the obtained substrate. By using the special ratio of the present application, a substrate with significantly improved surface stability can be prepared. Description of the drawings

[0022] Figure 1 It is a comparative schematic diagram of the bonding of a silane containing one silicon atom and a silane containing two silicon atoms with the glass slide surface respectively.

[0023] Figure 2 It is a comparative schematic diagram of the bonding of a silane containing two silicon atoms, and a mixed silane of a silane containing one silicon atom and a silane containing two silicon atoms with the glass slide surface.

[0024] Figure 3 It is a comparative diagram of the water contact angle measurement data in Example 4.

[0025] Figure 4 It is a comparative diagram of the water contact angle measurement data in Comparative Example 1. Specific embodiments

[0026] The technical solutions of the present invention will be further described in detail below with reference to specific embodiments. It should be understood that the following embodiments are only illustrative of and explanatory of the present invention, and should not be construed as limiting the protection scope of the present invention. All technologies implemented based on the above content of the present invention are covered within the scope of protection intended by the present invention.

[0027] Unless otherwise specified, the raw materials and reagents used in the following embodiments are all commercially available products, or can be prepared by known methods.

[0028] Example 1

[0029] Etch the glass slide in piranha solution for 30 min. After taking it out, ultrasonically clean it with deionized water and absolute ethanol for 1 min * 3 times, and dry it with nitrogen. Prepare an ethanol solution (ethanol: water = 95:5, v:v) containing 3 wt% bis(3-(trimethoxysilyl)propyl)amine, and adjust the pH of the solution to 4 with glacial acetic acid. Immerse the activated glass slide in the bis(3-(trimethoxysilyl)propyl)amine solution at room temperature overnight, ultrasonically clean it with absolute ethanol and deionized water for 1 min * 3 times, and place it in an oven at 100 °C to dry for 120 min.

[0030] Example 2

[0031] Wipe the glass slide clean with a lint-free cloth dipped in absolute ethanol, and activate it by oxygen plasma (200 w, 180 s). Prepare an ethanol mixed solution (ethanol: water = 95:5, v:v) containing 4 wt% aminopropyltriethoxysilane and 1 wt% bis(triethoxysilyl)methane, and adjust the pH of the solution to 4 with glacial acetic acid. Immerse the activated glass slide in the silane mixed solution at room temperature overnight, ultrasonically clean it with absolute ethanol and deionized water for 1 min * 3 times, and place it in an oven at 110 °C to dry for 60 min.

[0032] Example 3

[0033] Wipe the glass slide clean with a lint-free cloth dipped in absolute ethanol, and activate it by oxygen plasma (200 w, 180 s). Prepare an aqueous toluene solution (toluene: water = 98:2, v:v) containing 5 wt% vinylhexamethoxysilane , and adjust the pH to 4 with glacial acetic acid. Immerse the activated glass slide in the silane solution at room temperature overnight, ultrasonically clean it with toluene and deionized water for 1 min * 3 times, and place it in an oven at 110 °C to dry for 90 min.

[0034] Example 4

[0035] Wipe two glass slides clean with a lint-free cloth dipped in absolute ethanol, and activate them by oxygen plasma (200 w, 180 s). Respectively prepare an aqueous cyclohexane solution containing 5 wt% n-octyltrimethoxysilane and 2 wt% 1,8-bis(trimethoxysilyl)octane , an aqueous cyclohexane solution of 5 wt% n-octyltrimethoxysilane (cyclohexane: water = 97:3, v:v), and adjust the pH of the solution to 4 with glacial acetic acid. Immerse the two glass slides in the two silane solutions at room temperature for 10 h respectively, ultrasonically clean them with cyclohexane and deionized water for 1 min * 3 times, and place them in an oven at 110 °C to dry for 60 min. Use a contact angle measuring instrument to measure the water contact angles of the two glass slides respectively, and compare their hydrophobicity and stability. The water contact angle measurement data are statistically analyzed in Figure 3 . From Figure 3It can be seen that the stability of the modified layer on the surface modified with a mixed silane of n-octyltrimethoxysilane and 1,2-bis(trimethoxysilyl)octane is significantly enhanced compared to the surface modified with n-octyltrimethoxysilane alone (below). The glass slide can be placed for a longer time (when placed for 180 days, the water contact angle of the glass slide remains basically unchanged).

[0036] Comparative Example 1

[0037] The silane solution was replaced with a cyclohexane aqueous solution containing 5 wt% n-octyltrimethoxysilane and 0.2 wt% 1,8-bis(trimethoxysilyl)octane, and a cyclohexane aqueous solution containing 0.5 wt% n-octyltrimethoxysilane and 0.2 wt% 1,8-bis(trimethoxysilyl)octane (cyclohexane: water = 97:3, v:v). The pH of the solution was adjusted to 4 with glacial acetic acid. The glass slide treatment process was the same as in Example 4.

[0038] Measure its water contact angle, and the results are statistically shown in Figure 4 In Figure 4 In it, the test results of the glass slide treated with the cyclohexane aqueous solution containing 5 wt% n-octyltrimethoxysilane and 0.2 wt% 1,8-bis(trimethoxysilyl)octane are the upper line, and the test results of the glass slide treated with the cyclohexane aqueous solution containing 0.5 wt% n-octyltrimethoxysilane and 0.2 wt% 1,8-bis(trimethoxysilyl)octane are the lower line. Compared with Example 4, the effect of treating the glass slide with the above two cyclohexane aqueous solutions is not as good as that of Example 4 using a cyclohexane aqueous solution containing 5 wt% n-octyltrimethoxysilane and 2 wt% 1,8-bis(trimethoxysilyl)octane, and the surface stability of the treated glass slide decreases significantly with the extension of time.

[0039] Above, the embodiments of the present invention have been described. However, the present invention is not limited to the above embodiments. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principle of the present invention shall be included within the protection scope of the present invention.

Claims

1. A method for grafting and modifying on the surface of a substrate, characterized in that, It includes the following steps: Pre-treat the surface of the substrate material to connect hydroxyl, amino or mercapto groups to the surface of the substrate material, obtaining a pre-treated substrate; Then place the pre-treated substrate in a solution of a silane coupling agent containing two silicon atoms for reaction, or place the pre-treated substrate in a mixed solution of a silane coupling agent containing two silicon atoms and a silane coupling agent containing one silicon atom for reaction.

2. The method according to claim 1, characterized in that, The substrate material is a glass slide, a silicon wafer, PDMS or an aluminum sheet.

3. The method according to claim 1 or 2, characterized in that, The pre-treatment includes: ozone cleaning the substrate material under ultraviolet light, soaking treatment with a piranha solution or oxygen plasma treatment.

4. The method according to any one of claims 1-3, characterized in that, The concentration of the solution or mixed solution of the silane coupling agent is 1-15 wt%.

5. The method according to any one of claims 1-4, characterized in that, When using a silane coupling agent containing two silicon atoms and a silane coupling agent containing one silicon atom, the mass ratio of the silane coupling agent containing one silicon atom to the silane coupling agent containing two silicon atoms is 1:1 - 10:

1.

6. The method according to any one of claims 1-5, characterized in that, The silane coupling agent containing one silicon atom is selected from 3-aminopropyltriethoxysilane, 3-aminopropyltrimethoxysilane, γ-glycidoxypropyltrimethoxysilane, vinyltrimethoxysilane, n-octyltrimethoxysilane or n-decyltrimethoxysilane; Preferably, the silane coupling agent containing two silicon atoms is selected from bis(3-(trimethoxysilyl)propyl)amine, bis(triethoxysilyl)methane, bis(triethoxysilyl)ethane, vinylhexaethoxysilane or 1,8-bis(trimethoxysilyl)octane.

7. The method according to any one of claims 1-6, characterized in that, The pH of the solution of the silane coupling agent containing two silicon atoms, or its mixed solution with the silane coupling agent containing one silicon atom, is 3-5.

8. The method according to any one of claims 1-7, characterized in that, The reaction temperature of the pre-treated substrate material with the solution or mixed solution of the silane coupling agent is 0-40 °C.

9. A substrate prepared by the method according to any one of claims 1-8.

10. Use of the substrate according to claim 9 in analysis and detection.

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