High-throughput droplet plasmonic metasurface biochip based on wettability technique

Abstract

Disclosed is a high-throughput droplet plasmonic metasurface biochip based on wettability technology, comprising a black silicon super-hydrophobic region and a plasmonic metasurface region, the black silicon super-hydrophobic region comprising a substrate layer and a nano-spur layer connected to the surface of the substrate layer, and the structure of the plasmonic metasurface region from bottom to top comprising a substrate layer, a nano-pore structure layer and a metal film layer; the droplet plasmonic metasurface biochip provided by the application further accelerates the biological functionalization process in the biological detection step due to its wettability technology, and reduces the amount of reagent, effectively overcoming the problems of high cost and low efficiency of traditional biological detection, and providing a stable manufacturing method for the droplet plasmonic metasurface biochip, which combines wettability technology with plasmonic metasurfaces, and makes a significant contribution to subsequent mass production of more practical droplet plasmonic metasurface biochips.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of wettability technology and biochip, and particularly to a high-throughput droplet plasmonic metasurface biochip based on wettability technology. BACKGROUND

[0002] In recent years, spectral sensing technology plays an important role in the fields of biological medicine, environmental detection, chemical analysis, medical diagnosis, etc. Among them, the plasmonic metasurface biosensor has attracted a lot of attention due to its high efficiency, label-free and accuracy. The plasmonic metasurface biosensor commonly studied at present is mainly composed of various specific three-dimensional nanostructures of certain materials. The concentration of the detected substance is fitted by the resonance valley wavelength shift of the reflected light spectrum, so as to realize the function of biosensing.

[0003] The detection application of plasmonic metasurface needs to go through a biological functionalization process, which is generally carried out by using a microtiter plate, such as a 96-well plate. However, it has the disadvantages of large sample consumption, long incubation time, and low integration, which leads to poor timeliness and low fault tolerance in biological detection. Therefore, there is an urgent need for a more efficient plasmonic metasurface biosensor.

[0004] Nowadays, biomimetic wettability micro-patterns are gradually appearing in the field of biosensing workers. The biomimetic wettability micro-pattern usually refers to the combination of hydrophobicity and hydrophilicity in a precisely arranged two-dimensional micro-pattern, thereby forming a special two-dimensional array. This micro-pattern has excellent control and patterning microdroplet ability, and it is becoming a practical tool in various biomedical applications. However, there is still a lack of a product that combines wettability technology with plasmonic metasurfaces and a stable preparation method thereof. SUMMARY

[0005] In view of the technical problems of large sample consumption, long incubation time, and low integration in the prior art, the present application provides a high-throughput droplet plasmonic metasurface biochip based on wettability technology.

[0006] According to one aspect of the present application, a high-throughput droplet plasmonic metasurface biochip based on wettability technology is provided, which includes a black silicon super-hydrophobic region and a plasmonic metasurface region. The black silicon super-hydrophobic region includes a substrate layer and a nano-spine layer, and the nano-spine layer is connected to the surface of the substrate layer. The structure of the plasmonic metasurface region is sequentially arranged from bottom to top as a substrate layer, a nano-pore structure layer, and a metal thin film layer.

[0007] Further, the liquid droplet plasmonic super surface biochip has a size of 10*10mm-50*50mm, and includes 9-225 plasmonic super surface regions arranged in a periodic manner, wherein the plasmonic super surface regions have any one of a circular shape, a triangular shape, a square shape, a pentagonal shape, and a hexagonal shape, a diameter of 1mm-5mm, and a periodic shape of any one of a triangular shape, a square shape, a pentagonal shape, and a hexagonal shape, and a periodic distance of 1mm-5mm.

[0008] Further, the nano spike layer has any one of a conical shape, a circular truncated cone shape, a cylindrical shape, and a square column shape, and a height of 300nm-1200nm.

[0009] Further, the substrate layer and the nano spike layer are made of any one of Al2O3, Si, SiC, GaN, Ga2O3, PET, MgAl2O4, LiAlO2, and LiGaO2.

[0010] Further, the nano hole structure has a shape of a prism or a circular truncated cone, a periodic shape of any one of a triangular shape, a square shape, a pentagonal shape, and a hexagonal shape, a periodic distance of 450nm-500nm, a hole diameter of 350nm-400nm, and a hole depth of 100nm-200nm.

[0011] Further, the substrate layer and the nano hole structure layer are made of any one of Al2O3, Si, SiC, GaN, Ga2O3, PET, MgAl2O4, LiAlO2, and LiGaO2.

[0012] Further, the metal thin film layer is made of any one of Au, Ag, Pt, and Al.

[0013] According to a second aspect of the present application, a preparation method of a high-throughput liquid droplet plasmonic super surface biochip based on a wettability technology is provided, and the method includes the following steps:

[0014] S1, transferring nano structures on a nickel template to a polymer substrate by using a thermal nano imprinting process;

[0015] S2, processing photoresist to have a regular nano hole structure by using a UV nano imprinting photoetching process;

[0016] S3, processing the chip by using a plasma etching process to remove the photoresist on the top of the substrate layer and form a substrate layer with a regular nano hole structure;

[0017] S4, spin coating the photoresist on the substrate layer with the nano hole structure by using a spin coater;

[0018] S5, lay the mask with circular holes on the chip, expose the substrate layer, and develop in the developing solution;

[0019] S6, deposit a metal thin film layer on the circular substrate layer and the photoresist using a magnetron sputtering process;

[0020] S7, soak the chip in an acetone solution to strip the metal deposited on the photoresist together with the photoresist;

[0021] S8, etch the exposed substrate layer around the metal thin film layer downward to form a nano spike layer using a black silicon etching process.

[0022] Further, the implementation conditions of the thermal nanoimprint process in step S1 are 150 DEG C and 40 bar, the implementation conditions of the UV nanoimprint lithography process in step S2 are 65 DEG C and 3.0 x 10 6 Pa, and the implementation conditions of the black silicon etching process in step S8 are 0 DEG C.

[0023] Further, the black silicon etching process includes alternately pulsing the etching gas SF6 and the passivation gas C4F8, with a pulse time of 2 s and a flow rate of 100 sccm.

[0024] Compared with the prior art, the beneficial results of the present application are that:

[0025] (1) less sample consumption: only 2 muL of sample is required for single detection, effectively overcoming the high cost problem of traditional biological detection;

[0026] (2) faster incubation rate: the incubation time can be controlled within 15-20 minutes, with high detection efficiency;

[0027] (3) higher detection target integration: 9-225 sites can be detected quickly on a 3x3 cm biochip;

[0028] (4) the corresponding droplet plasmonic super surface biochip preparation process can realize batch preparation of biochips. BRIEF DESCRIPTION OF DRAWINGS

[0029] The accompanying drawings are included to provide a further understanding of the embodiments and are incorporated in and constitute a part of this specification. The drawings illustrate the embodiments and, together with the description, serve to explain the principles of the present application. Other embodiments and many of the intended advantages of the present application will be readily appreciated as the same becomes better understood by reference to the following detailed description when considered in connection with the accompanying drawings. The elements of the drawings are not necessarily to scale relative to each other. Like reference numerals designate corresponding similar parts.

[0030] Figure 1A single period microsectional view of the droplet plasmonic metasurface biochip of the present application is shown;

[0031] Figure 2 A scanning electron microscope image of the droplet plasmonic metasurface biochip of the present application is shown, wherein 2a is a 45° angle scanning electron microscope image of the black silicon superhydrophobic region in the droplet plasmonic metasurface biochip of the present application, and 2b is a 45° angle scanning electron microscope image of the plasmonic metasurface region in the droplet plasmonic metasurface biochip of the present application;

[0032] Figure 3 A contact angle measurement image of the droplet plasmonic metasurface biochip of the present application is shown, wherein, Figure 3 a is a contact angle measurement image of the black silicon superhydrophobic region in the droplet plasmonic metasurface biochip of the present application, Figure 3 b is a contact angle measurement image of the plasmonic metasurface region in the droplet plasmonic metasurface biochip of the present application.

[0033] Figure 4 A preparation flowchart of the droplet plasmonic metasurface biochip of the present application is shown;

[0034] Figure 5 A preparation flowchart of the droplet plasmonic metasurface biochip of the present application is shown. DETAILED DESCRIPTION

[0035] The present application will be further described below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are intended to be merely illustrative of the present application and not in limitation thereof. In addition, it should be noted that only the parts related to the present application are shown in the accompanying drawings for the convenience of description.

[0036] It should be noted that the embodiments in the present application and the features in the embodiments can be combined with each other without conflict. The present application will be described in detail below with reference to the accompanying drawings and embodiments.

[0037] The present application discloses a high-throughput droplet plasmonic metasurface biochip based on wettability technology, which realizes the integration, high-throughput and high-efficiency of the droplet plasmonic metasurface biochip.

[0038] Figure 1 A single period microsectional view of the droplet plasmonic metasurface biochip of the present application is shown, Figure 1As shown, the droplet plasmonic metasurface biochip comprises a black silicon super-hydrophobic region 110 and a plasmonic metasurface region 120. The black silicon super-hydrophobic region 110 comprises a substrate layer 111 and a nano-spur layer 112, and the nano-spur layer 112 is formed on the surface of the substrate layer 111 to generate a super-hydrophobic effect; the plasmonic metasurface region 120 comprises a substrate layer 121, a nano-pore structure layer 122 and a metal film layer 123, and the nano-pore structure layer 122 is formed on the substrate layer 121, and the metal film layer 123 is formed on the nano-pore structure layer 122 to interact with incident light to generate a plasmonic resonance effect.

[0039] The nano-spur layer 112 is randomly distributed on the upper surface of the substrate layer 111, and has a conical shape.

[0040] The shape of the nano-spur layer 112 can be changed according to the manufacturing process and product requirements to achieve different use effects, and there are various preferred solutions.

[0041] For example, the shape of the nano-spur layer 112 can be a cone, the upper surface of the cone is parallel to the upper and lower surfaces of the substrate layer 111, the side surface of the cone forms an angle with the upper surface of the substrate layer 111, and the angle can be preferably 40°-90°, and the lower surface of the nano-spur layer 112 (i.e. the lower surface of the cone) is tightly attached to the upper surface of the substrate layer 111.

[0042] For another example, the shape of the nano-spur layer 112 can be a cylinder, the upper surface of the cylinder is parallel to the upper and lower surfaces of the substrate layer 111, the side surface of the cylinder is perpendicular to the upper surface of the substrate layer 111, and the lower surface of the nano-spur layer 112 (i.e. the lower surface of the cylinder) is tightly attached to the upper surface of the substrate layer 111.

[0043] The height of the nano-spur layer 112 is not specifically constrained, and can be changed according to the manufacturing process and product requirements to achieve different use effects, and the height is preferably 300nm-1200nm. Specifically, for example, the height of the nano-spur layer 112 in the embodiment of the present application is 1000nm.

[0044] In addition, the materials of the substrate layer 111 and the nano-spur layer 112 can be selected from any material used as a black silicon substrate, including but not limited to the following materials, such as Al2O3, Si, SiC, GaN, Ga2O3, PET, MgAl2O4, LiAlO2 and LiGaO2. Specifically, for example, the material used in the embodiment of the present application is Si.

[0045] The nano-pore structure 122 is periodically and uniformly distributed on the upper surface of the substrate layer 121.

[0046] The shape of the nano-pore structure 122 can be changed according to the manufacturing process and product requirements to achieve different use effects, and there are various preferred solutions.

[0047] For example, the shape of the nano-pore structure 122 can be a prism, the upper surface of the prism is parallel to the upper and lower surfaces of the substrate layer 121, the side surface of the prism forms an included angle with the upper surface of the substrate layer 121, and the included angle can be preferably 40°-90°, and the lower surface of the nano-pore structure 122 (i.e. the lower surface of the prism) is closely attached to the upper surface of the substrate layer 121.

[0048] For another example, the shape of the nano-pore structure 122 can be a cylinder, the upper surface of the cylinder is parallel to the upper and lower surfaces of the substrate layer 121, the side surface of the cylinder is perpendicular to the upper surface of the substrate layer 121, and the lower surface of the nano-pore structure 122 (i.e. the lower surface of the cylinder) is closely attached to the upper surface of the substrate layer 121.

[0049] For another example, the shape of the nano-pore structure 122 can be a circular prism, the upper surface of the circular prism is parallel to the upper and lower surfaces of the substrate layer 121, the side surface of the circular prism forms an included angle with the upper surface of the substrate layer 121, and the included angle can be preferably 40°-90°, and the lower surface of the nano-pore structure 122 (i.e. the lower surface of the circular prism) is closely attached to the upper surface of the substrate layer 121.

[0050] The period, pore diameter and pore depth of the nano-pore structure 122 can be changed according to the manufacturing process and product requirements to achieve different use effects, and the period is preferably 450nm-500nm, the pore diameter is preferably 350nm-400nm, and the pore depth is preferably 100nm-200nm.

[0051] In addition, the materials of the substrate layer 121 and the nano-structure layer 122 can be any material that can be used as a substrate of a plasmonic metasurface, including but not limited to the following materials, such as Al2O3, Si, SiC, GaN, Ga2O3, PET, MgAl2O4, LiAlO2 and LiGaO2. Specifically, for example, the material used in the embodiment of the present application is Si.

[0052] There are also various preferred materials in the material selection scheme of the metal thin film layer 123, such as Au, Ag, Pt and Al. Specifically, for example, the material used in the embodiment of the present application is Au.

[0053] Figure 2 Fig. a is a 45° angle scanning electron microscope image of the black silicon super-hydrophobic region 110 in the liquid droplet plasmonic metasurface biochip, and it can be seen from the scanning electron microscope image of the black silicon super-hydrophobic region 110 in the liquid droplet plasmonic metasurface biochip that the black silicon super-hydrophobic region 110 in the present application generally has a sharp cone shape and good morphology.

[0054] Figure 2 b is the 45° angle scanning electron microscope image of the plasmonic super surface region 120 in the droplet plasmonic super surface biochip in the application, which can be seen from the scanning electron microscope image of the plasmonic super surface region 120 in the droplet plasmonic super surface biochip in the application that the size of the plasmonic super surface region 120 in the application is uniform and the morphology is good.

[0055] Figure 3 a is the contact angle measurement image of the black silicon super-hydrophobic region 110 in the droplet plasmonic super surface biochip in the application, which can be seen from the contact angle measurement image of the black silicon super-hydrophobic region 110 in the droplet plasmonic super surface biochip in the application that the black silicon super-hydrophobic region 110 prepared in the application has excellent hydrophobicity. Figure 3 As can be seen from a, the black silicon super-hydrophobic region 110 prepared in the application has excellent hydrophobicity, and the contact angle reaches 141.51° when 2 μL of deionized water is dropped on it.

[0056] Figure 3 b is the contact angle measurement image of the plasmonic super surface region 120 in the droplet plasmonic super surface biochip in the application, which can be seen from the contact angle measurement image of the plasmonic super surface region 120 in the droplet plasmonic super surface biochip in the application that the plasmonic super surface region 120 prepared in the application has excellent hydrophilicity. Figure 3 As can be seen from b, the plasmonic super surface region 120 prepared in the application has excellent hydrophilicity, and the contact angle reaches 89.42° when 2 μL of deionized water is dropped on it.

[0057] The application also provides a method for producing a high-throughput droplet plasmonic super surface biochip based on wettability technology, Figure 4 The production process of the droplet plasmonic super surface biochip in the application is shown, which comprises the following steps:

[0058] Step S1: Under the constant conditions of 150℃ and 40bar, the nickel nanostructure template is flatly laid above the polymer substrate, and the nanostructure is transferred to the polymer substrate by using a thermal nanoimprint process;

[0059] Preferably, the shape of the nanostructure in the nickel nanostructure template needs to be selected according to the pattern designed for the plasmonic super surface region 120 in the biochip. For example, the embodiment provided in the application uses a nano-hole array.

[0060] Preferably, the material of the polymer substrate can use one of polydimethylsiloxane (PDMS), polyvinyl alcohol resin (PVA), and hard-polydimethylsiloxane (h-PDMS).

[0061] Step S2: Under the constant conditions of 65℃ and 3.0×10 6 Pa, the transferred polymer substrate is flatly laid above the substrate of spin-coated photoresist, and the photoresist with regular nano-hole structure is processed and formed by using a UV nanoimprint lithography process;

[0062] Step S3: using a plasma etching process to treat the chip, removing the photoresist on top of the substrate layer 121 and forming a substrate layer 121 with a regular nano-hole structure;

[0063] Specifically, the plasma etching process used in the present application first uses an oxygen plasma etching process to thin the photoresist with a nano-hole structure to the substrate surface, exposing the underlying substrate in the nano-hole; secondly, using the remaining photoresist hole as a mask, the active ion etching process is used to continue etching the chip downward; finally, using an oxygen plasma etching process to etch the remaining photoresist on the substrate surface;

[0064] Step S4: using a spin coater to spin the photoresist on the substrate layer 121 with a nano-hole structure;

[0065] Step S5: lay the mask with a circular hole flat on the chip, use the photoetching process to expose the photoresist, and then perform the developing operation to modify the exposed area of the photoresist;

[0066] Step S6: using a magnetron sputtering process to deposit a metal thin film layer 123 on the exposed circular substrate layer 121 and photoresist;

[0067] Step S7: soak the chip in acetone solution for 12 hours to strip the metal deposited on the photoresist in the non-exposed area together with the photoresist;

[0068] Step S8: using a black silicon etching process to etch the exposed base layer 111 around the metal thin film layer 123 for 5 minutes at a constant temperature of 0°C to form a nano-spine layer 112;

[0069] Preferably, in the black silicon etching technology used in the present application, the etching gas SF6 and the passivation gas C4F8 are alternately pulsed, the pulse time of both gases is kept at 2s, and the flow rate is kept at 100sccm, so that the nano-spine layer 112 can be stably formed.

[0070] The above describes the specific embodiments of the present application, but the protection scope of the present application is not limited thereto, any person skilled in the art can easily think of changes or replacements within the technical scope disclosed in the present application, which should be covered within the protection scope of the present application. Therefore, the protection scope of the present application should be subject to the protection scope of the claims.

[0071] In the description of the application, it needs to be understood that the terms "upper", "lower", "inner", "outer" and the like indicate the orientation or positional relationship shown in the drawings based on the orientation or positional relationship shown in the drawings, and are only for the purpose of facilitating the description of the application and simplifying the description, and do not indicate or imply that the device or element referred to must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be understood as a limitation on the application. The word 'comprising' does not exclude the existence of elements or steps not listed in the claims. The word 'a' or 'an' in front of an element does not exclude the existence of multiple such elements. The mere fact that certain measures are recited in mutually different dependent claims does not indicate that the combination of these measures cannot be used to improve. Any reference signs in the claims should not be interpreted as limiting the scope.

Claims

1. A method for fabricating a high-throughput droplet plasmonic metasurface biochip based on wettability technology, characterized in that, include: S1. The nanostructure on the nickel template is transferred to the polymer substrate using a thermal nanoimprinting process. S2. A photoresist with a regular nanopore structure is formed by UV nanoimprint lithography. S3. Use plasma etching process to process the chip, remove the photoresist on the top of the substrate layer and form a substrate layer with a regular nanopore structure; S4. Spin-coat the photoresist onto the substrate layer with a nanoporous structure using a spin coater; S5. Lay a mask with circular holes flat on the chip, expose the substrate layer, and immerse it in a developing solution for development. S6. A metal thin film layer is deposited on the circular substrate and the photoresist using a magnetron sputtering process; S7. Soak the chip in acetone solution to peel off the metal deposited on the photoresist together with the photoresist. S8. Using a black silicon etching process, the exposed substrate layer around the metal thin film layer is etched downwards to form a nano-spiked layer; The implementation conditions for the thermal nanoimprinting process in step S1 are 150°C and 40 bar; the implementation conditions for the UV nanoimprinting lithography process in step S2 are 65°C and 3.0 × 10 Pa; and the implementation conditions for the black silicon etching process in step S8 are 0°C. The black silicon etching process includes alternating pulses of etching gas SF6 and passivation gas C4F8, with a pulse duration of 2 seconds and a flow rate of 100 sccm.

2. The method for preparing a high-throughput droplet plasmonic metasurface biochip according to claim 1, characterized in that, The droplet plasmonic metasurface biochip obtained by the preparation method includes a black silicon superhydrophobic region and a plasmonic metasurface region. The black silicon superhydrophobic region includes a substrate layer and a nanospike layer. The nanospike layer is connected to the surface of the substrate layer. The structure of the plasmonic metasurface region, from bottom to top, consists of a substrate layer, a nanoporous structure layer, and a metal thin film layer.

3. The method for preparing a high-throughput droplet plasmonic metasurface biochip according to claim 1, characterized in that, The droplet plasmon metasurface biochip obtained by the preparation method has a size of 10×10mm to 50×50mm, including 9 to 225 periodically distributed plasmon metasurface regions. The shape of the plasmon metasurface regions is any one of circular, triangular, square, pentagonal, and hexagonal, with a diameter of 1mm to 5mm. The periodic shape is any one of triangular, square, pentagonal, and hexagonal, with a periodic distance of 1mm to 5mm.

4. The method for preparing a high-throughput droplet plasmonic metasurface biochip according to claim 1, characterized in that, The shape of the nanospikes in the nanospike layer can be any one of a cone, frustum, cylinder, or square prism, and the height of the nanospike layer is 300nm to 1200nm.

5. The method for preparing a high-throughput droplet plasmonic metasurface biochip according to claim 1, characterized in that, The base layer and the nano-spiked layer are made of any one of Al2O3, Si, SiC, GaN, Ga2O3, PET, MgAl2O4, LiAlO2, and LiGaO2.

6. The method for preparing a high-throughput droplet plasmonic metasurface biochip according to claim 1, characterized in that, The shape of the nanopore structure includes a frustum or a truncated cone. The periodic shape of the nanopore structure is any one of a triangle, a square, a pentagon, or a hexagon. The periodic distance of the nanopore structure is 450nm to 500nm, the pore diameter is 350nm to 400nm, and the pore depth is 100nm to 200nm.

7. The method for preparing a high-throughput droplet plasmonic metasurface biochip according to claim 1, characterized in that, The substrate layer and the nanoporous structure layer are made of any one of Al2O3, Si, SiC, GaN, Ga2O3, PET, MgAl2O4, LiAlO2, and LiGaO2.

8. The method for preparing a high-throughput droplet plasmonic metasurface biochip according to claim 1, characterized in that, The material of the metal thin film layer is any one of Au, Ag, Pt and Al.

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