Raman detection chip and preparation method thereof

Abstract

The invention discloses a Raman detection chip. The Raman detection chip comprises a silicon wafer, a gold nano array and a reporter molecule layer, according to the Raman detection chip disclosed by the invention, the FDTD theory is adopted to calculate and optimize parameters which specifically comprise the height and the gap of the lug boss on the gold nano array, and the reporter molecules are modified on the upper surface of the gold nano array, so that the chip has the capability of specifically detecting specific metabolites. Therefore, the Raman detection chip provided by the embodiment of the invention can realize rapid and quantitative detection of the target metabolite.

Description

Technical Field

[0001] The present invention relates to the technical field of medical devices, and in particular to a Raman detection chip and a preparation method thereof. Background Art

[0002] The currently used Raman substrates cannot achieve high repeatability and specificity detection of target metabolites. The current Raman detection chips cannot meet the needs of rapid and quantitative detection of target biomolecules such as MMP, HClO, pH, GSH, and ROS.

[0003] It can be seen that whether it is possible to provide an improved Raman detection chip and preparation method based on the deficiencies in the prior art has become a technical problem that needs to be urgently solved by those skilled in the art. Summary of the invention

[0004] The technical problem to be solved by the present invention is to overcome the defects in the prior art and provide a Raman detection chip and a preparation method thereof.

[0005] The present invention solves the above technical problems through the following technical solutions:

[0006] A Raman detection chip, comprising:

[0007] Silicon wafer;

[0008] A gold nanoarray, comprising a photocurable prepolymer layer, a chromium film layer and a gold film layer, wherein the photocurable prepolymer layer is coated on the upper end of the silicon wafer, a plurality of convex portions arranged in an aligned array are formed on the upper surface of the photocurable prepolymer layer, the chromium film layer is coated on the surface of the convex portions and the upper surface of the photocurable prepolymer layer, and the gold film layer is coated on the upper surface of the chromium film layer;

[0009] The reporter molecule layer is arranged on the upper surface of the gold film layer, and reporter molecules are distributed in the reporter molecule layer.

[0010] Preferably, the reporter molecules include, but are not limited to, reporter molecules for MMP, HClO, pH, GSH, and ROS.

[0011] Preferably, the shape of the protrusion includes but is not limited to: cylindrical, triangular pyramidal, and square columnar.

[0012] Preferably, the cylinder has a diameter of 50-300 nm and a height of 70-200 nm.

[0013] Preferably, the triangular pyramid has a side length of 60-300 nm and a height of 100-200 nm.

[0014] Preferably, the side length of the square column is 50-300 nm, and the height is 100-200 nm.

[0015] Preferably, the thickness of the gold film layer is 10-50 nm.

[0016] Preferably, the size of the silicon wafer is 5 cm×5 cm.

[0017] A method for preparing a Raman detection chip, used for preparing the above-mentioned Raman detection chip, the method comprising the following steps:

[0018] Selecting a photocurable prepolymer with low viscosity and good leveling property, doping a photoinitiator and a reactive diluent to adjust the viscosity, spin coating the prepolymer on the silicon wafer, pressing a transparent template on the coating layer of the photocurable prepolymer, and irradiating the photocurable prepolymer with ultraviolet light to cure the photocurable prepolymer to form the photocurable prepolymer layer;

[0019] removing the transparent template, and spraying a layer of chrome film on the surface of the obtained protrusion and the upper surface of the photocurable prepolymer layer;

[0020] Spraying a layer of gold film on the upper surface of the chromium film layer;

[0021] A variety of reporter molecules are modified onto the upper surface of the gold film layer via gold-sulfur bonds.

[0022] Preferably, the photocurable prepolymer selected includes but is not limited to: polyurethane acrylate.

[0023] Preferably, the proportion of the photoinitiator is 13%-15%, and the proportion of the reactive diluent is 30%-60%.

[0024] Preferably, the method further comprises the following steps:

[0025] The transparent template is manufactured in advance by electron beam etching.

[0026] Preferably, the method further comprises the following steps:

[0027] According to the concentration range of the target metabolite in the extracellular fluid, the modification ratio of the corresponding reporter molecule on the gold nanoarray is adjusted.

[0028] On the basis of being in accordance with the common sense in the art, the above-mentioned preferred conditions can be arbitrarily combined to obtain the preferred embodiments of the present invention.

[0029] The positive and progressive effect of the present invention is that the Raman detection chip of the present invention includes a silicon wafer, a gold nanoarray and a reporter molecule layer. The Raman detection chip of the present invention uses FDTD theoretical calculation to optimize parameters, specifically including the height and gap of the protrusions on the gold nanoarray, and the reporter molecules are modified on the surface of the gold nanoarray, so that the chip has the ability to specifically detect specific metabolites. Therefore, the Raman detection chip of this embodiment can achieve rapid and quantitative detection of target metabolites. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] Figure 1 This is a cross-sectional view of a Raman detection chip according to a preferred embodiment of the present invention.

[0031] Figure 2 The figure is a flow chart of a method for preparing a Raman detection chip according to a preferred embodiment of the present invention.

[0032] Description of reference numerals:

[0033] Silicon wafer 1

[0034] Photocurable prepolymer layer 2

[0035] Raised portion 21

[0036] Gold film layer 3

[0037] Reporter 4

[0038] Chromium film layer 5 DETAILED DESCRIPTION

[0039] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, rather than all the embodiments. The following description of at least one exemplary embodiment is actually only illustrative and is by no means intended to limit the present invention and its application or use. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0040] For ease of description, spatially relative terms such as "above", "above", "on the upper surface of", "above", etc. may be used here to describe the spatial positional relationship between a device or feature and other devices or features as shown in the figure. It should be understood that spatially relative terms are intended to include different orientations of the device in use or operation in addition to the orientation described in the figure. For example, if the device in the accompanying drawings is inverted, the device described as "above other devices or structures" or "above other devices or structures" will be positioned as "below other devices or structures" or "below other devices or structures". Thus, the exemplary term "above" can include both "above" and "below". The device can also be positioned in other different ways (rotated 90 degrees or in other orientations), and the spatially relative descriptions used here are interpreted accordingly.

[0041] like Figure 1 As shown, this embodiment discloses a Raman detection chip, which includes a Raman substrate and a reporter molecule layer.

[0042] The Raman substrate includes a silicon wafer 1 and a gold nanoarray. The Raman substrate with an array structure is the key to improving detection sensitivity, stability and repeatability. The gold nanoarray includes a photocurable prepolymer layer 2, a chromium film layer 5 and a gold film layer 3. The photocurable prepolymer layer 2 is covered on the upper end of the silicon wafer 1. The upper surface of the photocurable prepolymer layer 2 is formed with a plurality of aligned and arrayed protrusions 21. The protrusions 21 and the photocurable prepolymer layer 2 are integrally formed.

[0043] The thickness of the chromium film layer 5 is 5 nm, and it covers the surface of the protrusion and the upper surface of the photocurable prepolymer layer. The chromium film layer 5 covers the entire surface of the protrusion 21 and the portion of the upper surface of the photocurable prepolymer layer 2 without the protrusion 21. That is, the chromium film layer 5 is a whole, completely covering the protrusion 21 and the upper surface of the photocurable prepolymer layer 2.

[0044] The thickness of the gold film layer 3 is 10-50 nm, and it covers the upper surface of the chromium film layer 5 .

[0045] The Raman detection chip disclosed in this embodiment includes, in addition to the above-mentioned Raman substrate, a reporter molecule layer disposed on the upper surface of the gold film layer of the gold nanoarray, and reporter molecules 4 are distributed in the reporter molecule layer.

[0046] In this embodiment, the reporter molecules 4 include, but are not limited to: reporter molecules 4 for MMP, HClO, pH, GSH, and ROS.

[0047] Raman detection chip is the core of target metabolite detection, and reporter molecule 4 is the key to rapid and quantitative detection of target metabolites in samples. The design of reporter molecule 4 needs to meet the following conditions: (1) It can be covalently labeled to the surface of gold nanoarray to improve detection stability and repeatability; (2) The characteristic peaks of different reporter molecules 4 are intertwined and can be accurately identified in the spectrum of complex biological systems; (3) Reporter molecule 4 binds / reacts quickly with the target metabolite, and the characteristic peak of reporter molecule 4 has a ratiometric response characteristic during the binding process; (4) Reporter molecule 4 is highly specific to the target metabolite and will not be interfered by other compounds in the sample and microenvironmental factors.

[0048] Further, in this embodiment, the size of the silicon wafer 1 is 5 cm×5 cm. The shape of the protrusion 21 includes but is not limited to: cylindrical, triangular pyramid, and square column. When the protrusion 21 is cylindrical, the diameter of the cylinder is 50-300 nm and the height is 70-200 nm. When the protrusion 21 is a triangular pyramid, the side length of the triangular pyramid is 60-300 nm and the height is 100-200 nm. When the protrusion 21 is a square column, the side length of the square column is 50-300 nm and the height is 100-200 nm.

[0049] like Figure 2 As shown, this embodiment also discloses a method for preparing a Raman detection chip, which is used to prepare the above-mentioned Raman detection chip, and the method comprises the following steps:

[0050] A photocurable prepolymer with low viscosity and good leveling property, such as polyurethane acrylate (PUA), but not limited thereto, is selected, 13%-15% photoinitiator and 30%-60% active diluent are doped to adjust the viscosity, and the prepolymer is spin-coated on a cleaned silicon wafer 1, and a transparent template pre-made by electron beam etching is pressed on the coating layer of the photocurable prepolymer. The photocurable prepolymer is irradiated with ultraviolet light to cure the photocurable prepolymer to form a Raman-based photocurable prepolymer layer 2.

[0051] The transparent template is removed, and a 5 nm chromium layer is sprayed on the surface of the obtained protrusion 21 and the upper surface of the photocurable prepolymer layer 2 (to increase adhesion), and then a 10-50 nm thick gold film is evaporated.

[0052] A variety of reporter molecules 4 are modified onto the upper surface of the gold film layer via highly stable gold-sulfur bonds.

[0053] The method for preparing the Raman detection chip of this embodiment also includes the step of adjusting the modification ratio of the corresponding reporter molecule 4 on the gold nanoarray according to the concentration range of the target metabolite in the extracellular fluid to achieve accurate identification and reading of different types of metabolites.

[0054] The reporter molecule 4 modified on the surface of the Raman detection chip will specifically identify the target metabolite in the droplet sample, and the binding / reaction between the reporter molecule 4 and the metabolite will promote the ratio-type change in the characteristic Raman signal of the reporter molecule 4. The principle of signal change is: the metabolite response reporter molecule 4 specifically recognizes and binds to the target detection object, causing the charge redistribution within the reporter molecule 4. The chemical bond charge on the non-conjugated system changes (is affected) less, and its corresponding Raman peak intensity remains unchanged, while the chemical bond charge inside the conjugated system changes significantly (affected to varying degrees), and its Raman peak intensity is also enhanced to varying degrees, and the quantitative detection of metabolites is achieved according to the intensity ratio between the spectral peaks. Therefore, the Raman substrate of this embodiment can achieve high specificity and high repeatability detection of target metabolites.

[0055] The Raman detection chip of this embodiment uses FDTD theoretical calculation to optimize parameters, including the height and gap of the protrusions on the gold nanoarray, and the reporter molecules are modified on the surface of the gold nanoarray, so that the chip has the ability to specifically detect specific metabolites. If the reporter molecules are not modified, the detected signal is either very weak and difficult to identify, or is interfered with by the signals of non-target detection objects in complex samples and is masked. Therefore, the Raman detection chip of this embodiment can achieve rapid and quantitative detection of target metabolites.

[0056] It should be noted that in the claims and description of this patent, the terms "include", "comprises" or any other variants thereof are intended to cover non-exclusive inclusion, so that a process, method, article or device including a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, article or device. In the absence of further restrictions, the elements defined by the sentence "comprises a" do not exclude the existence of other identical elements in the process, method, article or device including the elements.

Claims

1. A Raman detection chip, It is characterized in that include: Silicon wafer; A gold nanoarray, comprising a photocurable prepolymer layer, a chromium film layer and a gold film layer, wherein the photocurable prepolymer layer is coated on the upper end of the silicon wafer, a plurality of convex portions arranged in an aligned array are formed on the upper surface of the photocurable prepolymer layer, the chromium film layer is coated on the surface of the convex portions and the upper surface of the photocurable prepolymer layer, and the gold film layer is coated on the upper surface of the chromium film layer; The reporter molecule layer is arranged on the upper surface of the gold film layer, and reporter molecules are distributed in the reporter molecule layer.

2. The Raman detection chip according to claim 1, It is characterized in that The reporter molecules include, but are not limited to, reporter molecules for MMP, HClO, pH, GSH, and ROS.

3. The Raman detection chip according to claim 1, It is characterized in that The shape of the protrusion includes but is not limited to: cylindrical, triangular pyramid, and square column.

4. The Raman detection chip according to claim 3, It is characterized in that The cylinder has a diameter of 50-300 nm and a height of 70-200 nm.

5. The Raman detection chip according to claim 3, It is characterized in that The triangular pyramid has a side length of 60-300 nm and a height of 100-200 nm.

6. The Raman detection chip according to claim 3, It is characterized in that The side length of the square column is 50-300nm, and the height is 100-200nm.

7. The Raman detection chip according to claim 1, It is characterized in that The thickness of the gold film layer is 10-50 nm.

8. The Raman detection chip according to claim 1, It is characterized in that The size of the silicon wafer is 5 cm×5 cm.

9. A method for preparing a Raman detection chip, It is characterized in that For preparing the Raman detection chip according to any one of claims 1 to 8, the method comprises the following steps: Selecting a photocurable prepolymer with low viscosity and good leveling property, doping a photoinitiator and a reactive diluent to adjust the viscosity, spin coating the prepolymer on the silicon wafer, pressing a transparent template on the coating layer of the photocurable prepolymer, and irradiating the photocurable prepolymer with ultraviolet light to cure the photocurable prepolymer to form the photocurable prepolymer layer; removing the transparent template, and spraying a layer of chrome film on the surface of the obtained protrusion and the upper surface of the photocurable prepolymer layer; Spraying a layer of gold film on the upper surface of the chromium film layer; A variety of reporter molecules are modified onto the upper surface of the gold film layer via gold-sulfur bonds.

10. The method for preparing the Raman detection chip according to claim 9, It is characterized in that The selected photocurable prepolymer includes but is not limited to polyurethane acrylate.

11. The method for preparing the Raman detection chip according to claim 9, It is characterized in that The proportion of the photoinitiator is 13%-15%, and the proportion of the reactive diluent is 30%-60%.

12. The method for preparing the Raman detection chip according to claim 9, It is characterized in that The following steps are also included: The transparent template is manufactured in advance by electron beam etching.

13. The method for preparing the Raman detection chip according to claim 9, It is characterized in that The following steps are also included: According to the concentration range of the target metabolite in the extracellular fluid, the modification ratio of the corresponding reporter molecule on the gold nanoarray is adjusted.

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