A multi-gas detection chip and preparation method thereof

Abstract

The present invention relates to the field of gas detection elements, and discloses a multi-gas detection chip and a preparation method thereof, wherein the multi-gas detection chip comprises a base layer, an array layer and a covering layer; the array layer is arranged on the base layer, and the array layer is composed of a plurality of metal nanoparticles arranged according to a preset arrangement rule; the covering layer is arranged on the array layer; the covering layer comprises a plurality of first covering layers, and the plurality of first covering layers respectively cover different areas of the array layer, and the plurality of first covering layers completely cover the array layer. In this way, the obtained multi-gas detection chip has the advantages of high selectivity, high detection sensitivity, small size, easy integration, and the ability to quickly detect multiple gases simultaneously.

Description

Technical Field

[0001] The invention relates to the field of gas detection elements, and in particular to a multi-gas detection chip and a preparation method thereof. Background Art

[0002] The use of sensor devices to detect the type and concentration of gases in the environment has a wide range of applications in production and life fields such as environmental monitoring, public health, life health, and biosafety. Optical detection is one of the important means of gas sensing detection. Compared with traditional sensing detection methods, optical detection technology does not require sample preparation and has the advantages of being fast, non-invasive, efficient, and dynamic. It is suitable for rapid on-site detection and continuous real-time online analysis. Plasmon-based nanophotonic sensing is sensitive to changes in the refractive index of the surrounding environment and is an excellent candidate technology for optical detection.

[0003] According to the boundary conditions of the nanostructure geometry, plasmons can be divided into two different forms: surface plasmon polaritons (SPP) generated at the interface of metal nanofilm and dielectric and localized surface plasmons (LSPR) supported by metal nanoparticles. The surface plasmon polaritons (SPP) structure requires precise control of the non-vertical light incident angle, which makes it difficult to miniaturize and integrate the overall device, and is easily affected by the body effect, resulting in low detection selectivity. The localized surface plasmon polaritons (LSPR) structure has a low exciton quality factor. Since the detection sensitivity of plasmon sensing is proportional to the exciton quality factor, the detection sensitivity of the localized surface plasmon polaritons (LSPR) structure is low. In addition, under normal circumstances, the refractive index of the substrate of the surface plasmon polaritons (SPP) structure and the localized surface plasmon polaritons (LSPR) structure is much larger than the refractive index of the gas. The non-uniform refractive index around the nanoparticles will hinder the realization of high-quality plasmon resonance peaks, thereby limiting the high-sensitivity detection of gas by the plasmon structure. Moreover, both the surface plasmon polariton (SPP) structure and the localized surface plasmon polariton (LSPR) structure usually have only a single plasmon structure, resulting in a lack of selectivity for detecting different gases, and cannot achieve simultaneous detection of multiple different gases, and cannot meet the needs of rapid detection of multiple gases in a mixed gas environment. Summary of the invention

[0004] The present invention aims to solve the technical problems that the gas detection device is large in size, difficult to integrate, has low selectivity and low detection sensitivity, and cannot realize rapid detection of multiple gases simultaneously.

[0005] To solve the above technical problems, the present application discloses, in one aspect, a multi-gas detection chip, including a substrate layer, an array layer, and a cover layer;

[0006] The array layer is arranged on the base layer, and the array layer is composed of a plurality of metal nanoparticles arranged according to a preset arrangement rule;

[0007] The covering layer is arranged on the array layer; the covering layer comprises multiple layers of first covering layers, the multiple layers of first covering layers respectively cover different regions of the array layer, and the multiple layers of first covering layers completely cover the array layer.

[0008] Furthermore, the plurality of metal nanoparticles in the array layer have the same size and shape.

[0009] Furthermore, the structures of the multiple layers of first covering layers are all different and are used to adsorb different gases to be detected.

[0010] In another aspect, the present application discloses a method for preparing a plurality of gas detection chips, the method comprising:

[0011] Determining a preset arrangement rule, size and shape of a plurality of metal nanoparticles in an array layer;

[0012] forming an array layer on the substrate layer based on a preset arrangement rule, size and shape of the plurality of metal nanoparticles;

[0013] Dividing the array layer into a plurality of regions of the same size, and determining the arrangement, size and shape of the holes in the hole mask based on the plurality of regions;

[0014] Based on the hole mask, using different preparation materials, a covering layer that completely covers the multiple regions is formed on the multiple regions to obtain an initial detection array; the covering layer includes multiple first covering layers; the multiple first covering layers respectively cover different regions in the multiple regions;

[0015] The initial detection array is diced to obtain at least one multi-gas detection chip; each multi-gas detection chip includes the multi-layer first covering layer.

[0016] Furthermore, the method for determining the preset arrangement rule, size and shape of the plurality of metal nanoparticles in the array layer is a finite difference time domain method.

[0017] Further, based on the preset arrangement rules, sizes and shapes of the plurality of metal nanoparticles, an array layer is formed on the substrate layer, comprising:

[0018] Based on the preset arrangement rules, sizes and shapes of the plurality of metal nanoparticles, a photoresist array is formed on the substrate layer;

[0019] forming a metal film on the substrate layer based on a photoresist array;

[0020] forming an array layer on the base layer based on the metal thin film;

[0021] The metal film is peeled off from the base layer.

[0022] Further, based on the preset arrangement rules, sizes and shapes of the plurality of metal nanoparticles, a photoresist array is formed on the substrate layer, including:

[0023] Designing a photoresist array mold based on a preset arrangement rule, size and shape of a plurality of metal nanoparticles;

[0024] A photoresist array is formed by imprinting a photoresist array mold on the base layer.

[0025] Further, the arrangement, size and shape of the holes in the hole mask are determined based on the multiple regions, including:

[0026] Determining that the size and shape of the aperture in the aperture mask are consistent with the size and shape of each of the plurality of regions;

[0027] The arrangement of the holes in the hole mask is determined to be consistent with the arrangement position of one of the multiple regions in the array layer.

[0028] Furthermore, the method of forming the covering layer on the multiple regions to completely cover the multiple regions is spray deposition.

[0029] Furthermore, based on the hole mask, different preparation materials are used to form a covering layer that completely covers the multiple regions on the multiple regions, thereby obtaining an initial detection array, including:

[0030] Aligning the hole on the hole mask with one of the multiple regions;

[0031] Based on the hole mask, spraying the prepared raw material on the array layer to form a first covering layer;

[0032] Moving the hole mask until the hole on the hole mask corresponds to one of the multiple regions where the first covering layer is not formed;

[0033] Replacement of preparation raw materials;

[0034] Based on the moved hole mask, spraying the replaced prepared raw material on the array layer to form a first covering layer;

[0035] Repeat the steps: move the hole mask until the hole on the hole mask corresponds to one of the multiple regions where the first covering layer is not formed; replace the preparation raw material; based on the moved hole mask, spray the replaced preparation raw material on the array layer to form a first covering layer; until a first covering layer is formed on multiple regions to obtain an initial detection array.

[0036] By adopting the above technical solution, the various gas detection chips provided in this application have the following beneficial effects:

[0037] The multiple gas detection chip disclosed in the present application includes a base layer, an array layer and a covering layer; the array layer is arranged on the base layer, and the array layer is composed of multiple metal nanoparticles arranged according to a preset arrangement rule; the covering layer is arranged on the array layer; the covering layer includes multiple first covering layers, and the multiple first covering layers respectively cover different areas of the array layer, and the multiple first covering layers completely cover the array layer. In this way, the obtained multiple gas detection chip has the advantages of high selectivity, high detection sensitivity, small size, easy integration, and the ability to quickly detect multiple gases simultaneously. BRIEF DESCRIPTION OF THE DRAWINGS

[0038] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the drawings required for use in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work.

[0039] Figure 1 A schematic diagram of the structure of a multi-gas detection chip provided in an embodiment of the present application;

[0040] Figure 2 A schematic diagram of a method for preparing a multi-gas detection chip provided in an embodiment of the present application;

[0041] Figure 3 A schematic diagram of a method for preparing a multi-gas detection chip provided in an embodiment of the present application;

[0042] Figure 4 A schematic diagram of a method for preparing a multi-gas detection chip provided in an embodiment of the present application;

[0043] Figure 5 A schematic diagram of a method for preparing a multi-gas detection chip provided in an embodiment of the present application;

[0044] Figure 6 A schematic diagram of a method for preparing a multi-gas detection chip provided in an embodiment of the present application;

[0045] Figure 7 A schematic diagram of a method for preparing a multi-gas detection chip provided in an embodiment of the present application;

[0046] Figure 8 A schematic diagram of a method for preparing a multi-gas detection chip provided in an embodiment of the present application;

[0047] Fig. 9 A schematic diagram of a method for preparing a multi-gas detection chip provided in an embodiment of the present application;

[0048] Fig.10 A schematic diagram of a method for preparing a multi-gas detection chip provided in an embodiment of the present application;

[0049] Fig.11 A schematic diagram of a method for preparing a multi-gas detection chip provided in an embodiment of the present application;

[0050] Fig.12 A schematic flow chart of a method for preparing a multi-gas detection chip provided in an embodiment of the present application.

[0051] The following is a supplementary description of the attached drawings:

[0052] 1-base layer; 110-photoresist array; 120-metal film; 2-array layer; 21-metal nanoparticles; 200-photoresist array mold; 3-covering layer; 300-hole mask; 31-first covering layer; 311-first layer first covering layer; 312-second layer first covering layer; 313-third layer first covering layer; 314-fourth layer first covering layer; 4-initial detection array; 5-multiple gas detection chips. DETAILED DESCRIPTION

[0053] The technical solutions in the embodiments of the present application will be described clearly and completely below in conjunction with the drawings in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of this application.

[0054] The term "one embodiment" or "embodiment" as used herein refers to a specific feature, structure or characteristic that may be included in at least one implementation of the present application. In the description of the present application, it should be understood that the orientation or positional relationship indicated by the terms "upper", "lower", "top", "bottom", etc. is based on the orientation or positional relationship shown in the accompanying drawings, which is only for the convenience of describing the present application and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation of the present application. In addition, the terms "first" and "second" are used only for descriptive purposes, and cannot be understood as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Thus, the features defined as "first" and "second" may include one or more of the features explicitly or implicitly. Moreover, the terms "first", "second", etc. are used to distinguish similar objects, and are not necessarily used to describe a specific order or sequence. It should be understood that the data used in this way can be interchangeable where appropriate, so that the embodiments of the present application described here can be implemented in an order other than those illustrated or described here.

[0055] Figure 1 A schematic diagram of the structure of a gas detection chip provided in an embodiment of the present application is shown. Figure 1 As shown, the multi-gas detection chip includes a base layer 1, an array layer 2 and a multi-layer covering layer 3. The array layer 2 is arranged on the base layer 1, and the covering layer 3 is arranged on the array layer 2.

[0056] As an optional implementation, the array layer 2 is composed of a plurality of metal nanoparticles 21. The plurality of metal nanoparticles 21 are arranged according to a preset arrangement rule, and each of the metal nanoparticles 21 has the same size and shape.

[0057] A plurality of metal nanoparticles 21 arranged according to a preset arrangement rule form a regular array, so that the localized surface plasmons excited by the plurality of metal nanoparticles 21 are coupled with the Rayleigh anomalous diffraction light of the array layer 2 as a whole to form a surface lattice resonance. Surface lattice resonance can greatly reduce the resonance peak width and improve the quality factor of plasmon resonance, thereby improving detection sensitivity. In addition, the plurality of metal nanoparticles 21 forming a regular array can further enhance the near-field coupling enhancement effect of plasmons, and retain the ultra-small mode volume and vertical incident excitation characteristics of the unit hotspot formed by a single metal nanoparticle 21. The ultra-small mode volume means that the body effect of the array layer 2 is weak, thereby improving selectivity; vertical incident excitation means that no additional angle correction components are required, making the entire device smaller and easier to integrate.

[0058] As an optional implementation, by simulating the array structure of the metal nanoparticles 21, screening and optimizing various structural parameters from multiple simulation results, an array structure that can optimize the detection accuracy of multiple gas detection chips is determined, and the preset arrangement rules of the array layer 2 and the material, shape and size of the metal nanoparticles 21 therein are determined based on the array structure.

[0059] As an optional implementation, the covering layer 3 includes multiple layers of first covering layers 31 , each of which covers different areas of the array layer 2 without overlapping each other, and the multiple layers of first covering layers 31 completely cover the array layer 2 .

[0060] As an optional embodiment, the covering layer 3 completely wraps all the metal nanoparticles 21 in the array layer 2 and fully fills the gaps between the metal nanoparticles 21, that is, the thickness of the covering layer 3 is greater than the height of the metal nanoparticles 21, so that the surrounding areas of the metal nanoparticles 21 can be affected by the enrichment of gas molecules and the change of refractive index by the covering layer 3.

[0061] As an optional implementation, the covering layer 3 is a metal organic framework (MOFs).

[0062] Metal organic frameworks (MOFs) are a type of porous crystalline material formed by self-assembly of metal centers and organic ligands. They have the characteristics of ultra-high surface area, porosity, adjustable pore size, and easy functionalization. The surface area of ​​MOFs ranges from 100 to 7000 m2 / g, and the pore size can be controlled to be 3 to 100Å. They also have high thermal stability and chemical stability. Using the metal organic framework as the covering layer 3, on the one hand, enables the covering layer 3 to have the ability to enrich gas molecules and enhance the adsorption of gas molecules, thereby increasing the refractive index change caused by gas adsorption and improving the detection sensitivity; on the other hand, it can increase the refractive index around the metal nanoparticles 21, thereby establishing a uniform refractive index environment around the metal nanoparticles 21, thereby achieving high-quality plasmon resonance peaks and further improving the detection sensitivity. In addition, the regular and adjustable distribution of the metal organic framework (MOFs) pores and the multifunctionalization of the pore surface can achieve gas selective enrichment and improve the selectivity of gas detection.

[0063] As an optional embodiment, each first covering layer 31 in the covering layer 3 has a different structure and is composed of different materials, which can enrich different gas molecules, thereby realizing the detection of different gas molecules and meeting the needs of rapid and simultaneous detection of multiple gases in a mixed gas environment.

[0064] As an implementation mode, each first covering layer 31 in the covering layer 3 has a different structure, specifically, it has different metal centers, different morphologies, sizes, pore surfaces and specific pore size distributions.

[0065] As an optional implementation, the material of the base layer 1 includes silicon dioxide.

[0066] As an optional implementation, the material of the base layer 1 may also be other high temperature resistant transparent materials, such as sapphire and other materials.

[0067] As an optional implementation, there are multiple options for the material of the array layer 2, and the material that meets the detection requirements can be determined based on simulation.

[0068] on the other hand, Figure 2-Figure 12 A schematic diagram of a method for preparing a plurality of gas detection chips provided in an embodiment of the present application is shown. Figure 2-Figure 12 As shown, the method includes:

[0069] S201 : Determine a preset arrangement rule, size and shape of a plurality of metal nanoparticles 21 in the array layer 2 .

[0070] In the embodiment of the present application, the array structure of the metal nanoparticles 21 is simulated, and the various structural parameters are screened from multiple simulation results to optimize the array structure that can optimize the detection accuracy of multiple gas detection chips, and the array layer 2 is designed according to the array structure. The preset arrangement rules of the array layer 2 and the material, shape, size, surface and structure and internal structure of the metal nanoparticles 21 therein.

[0071] As an optional implementation, simulation is performed using a finite-difference time-domain method.

[0072] As an optional implementation, the optimal array structure is determined by calculating the far-field optical response and near-field optical response of the plasmon structure under illumination under the simulated array structure. According to the resonance spectrum of the array structure in the far-field optical response, the position, half-peak width and intensity of the resonance peak are obtained, and according to the range and intensity of the plasmon hotspot in the near-field optical response, the size and arrangement rules of the metal nanoparticles 21 are determined.

[0073] As an optional implementation, the array structure of the array layer 2 may include parameters such as the material, shape, size, surface structure, internal structure and arrangement rule of the metal nanoparticles 21 .

[0074] S203 : forming an array layer 2 on the base layer 1 based on the preset arrangement rule, size and shape of the plurality of metal nanoparticles 21 .

[0075] In the embodiment of the present application, in the formed array layer 2, the size and shape of the metal nanoparticles 21 are consistent with the preset parameters, and are arranged into an array according to the preset arrangement rules.

[0076] As an alternative, Figure 2-Figure 6 As shown, step S203: forming an array layer 2 on the base layer 1 based on the preset arrangement rule, size and shape of the plurality of metal nanoparticles 21, may include the following steps:

[0077] S301 : forming a photoresist array 110 on the base layer 1 based on the preset arrangement rule, size and shape of the plurality of metal nanoparticles 21 .

[0078] In the embodiment of the present application, a photoresist array mold 200 is designed based on a preset arrangement rule, size and shape of the plurality of metal nanoparticles 21 , and then the photoresist array 110 is formed by embossing the photoresist array mold 200 on the base layer 1 .

[0079] As an optional embodiment, the recessed area of ​​the photoresist array mold 200 corresponds to the position of the metal nanoparticles 21 in the array layer 2. Correspondingly, the photoresist array 110 formed by embossing has a plurality of protrusions, which are consistent with the arrangement of the metal nanoparticles 21 in the pre-designed array layer 2.

[0080] As an optional implementation, the photoresist array 110 may be formed by using a polydimethylsiloxane (PDMS) nanostamp imprinting method.

[0081] As an optional implementation, a transparent substrate such as glass or polydimethylsiloxane may be used as the material of the base layer 1 , which is used as the base for forming the photoresist array 110 .

[0082] S303 : forming a metal thin film 120 on the base layer 1 based on the photoresist array 110 .

[0083] In the embodiment of the present application, a metal film 120 is formed by depositing metal on the base layer 1 at the area not blocked by the photoresist array 110 by a metal deposition method. The positions of the gaps in the formed metal film 120 correspond to the protrusions of the photoresist array 110 one by one.

[0084] As an optional embodiment, the thickness of the metal film 120 can be used to further adjust the size of the gaps in the metal film 120, that is, during the deposition process, the deposited metal will gradually squeeze the gaps, causing the gaps to gradually decrease. The thicker the deposited metal film 120, the smaller the gaps in the metal film. Therefore, the gaps in the metal film 120 are adjusted by changing the thickness of the deposited metal film 120, and ultimately the size of the metal nanoparticles 21 in the formed array layer 2 is adjusted.

[0085] As an optional implementation, the material of the metal film 120 may be metal materials such as gold, copper, silver, and aluminum. S305 : forming an array layer 2 on the base layer 1 based on the metal film 120 .

[0086] In the embodiment of the present application, the metal film 120 acts as a physical deposition mask on the base layer 1. When metal deposition is performed on the base layer 1, metal nanoparticles 21 of the array layer 2 are formed at the positions of the gaps in the metal film 120, and the metal film 120 is peeled off, thereby forming the array layer 2 on the base layer 1. The positions of the metal nanoparticles 21 correspond one-to-one to the positions of the protrusions of the photoresist array 110, and the positions of the protrusions of the photoresist array 110 are consistent with the pre-designed arrangement of the metal nanoparticles 21, so that the metal nanoparticles 21 finally formed are arranged according to the pre-designed arrangement.

[0087] S307 : peeling the metal film 120 from the base layer 1 .

[0088] In the embodiment of the present application, the metal film 120 is only used as a physical deposition mask to form the array layer 2 . After the array layer 2 is deposited, the metal film 2 is peeled off to further form a covering layer 3 on the array layer 2 .

[0089] As an optional embodiment, the metal film 120 may not be formed directly on the base layer 1, but may be formed on another base and then transferred to the base layer 1, so that the metal film 120 can be easily peeled off from the base layer 1 after the array layer 2 is formed.

[0090] Specifically, a separate substrate is selected, and a photoresist array 110 is formed on the substrate according to step S301, and then a sacrificial layer is formed on the substrate where it is not blocked by the photoresist array 110 by a metal deposition method, and then a metal film 120 is further deposited on the sacrificial layer. The sacrificial layer is removed in a wet etching solution, thereby separating the metal film 120 from the substrate. The metal film 120 is transferred to water, so that the metal film 120 floats on the water surface, and then the metal film 120 is picked up by the base layer 1, so that the metal film 120 is transferred to the base layer 1. The metal film 120 thus obtained is not deposited on the base layer 1, and can be directly separated from the base layer 1 after use, which is convenient for operation, and can be reused to a certain extent, thereby reducing costs.

[0091] As an optional implementation, the substrate for preparing the metal film 120 may be a quartz sheet.

[0092] As an optional implementation, the material of the sacrificial layer may be a metal material such as chromium, titanium, etc.

[0093] As an optional implementation, after the array layer 2 is formed, it is treated by an annealing process to optimize the crystal structure and surface shape inside the metal nanoparticles 21, thereby obtaining a high-quality array layer 2 and ultimately generating a high-quality surface lattice resonance.

[0094] In the prior art, single-crystal nanoparticles are usually prepared by chemical synthesis, or regular arrays are prepared by micro-nano processing methods such as photolithography to form the array layer 2. However, the array arrangement of single-crystal nanoparticles prepared by chemical synthesis is difficult to control; although micro-nano processing methods such as photolithography can prepare regular arrays, the particles formed by evaporation / electroplating are polycrystalline and irregular in shape on the nanoscale, and the surface lattice resonance of the array layer 2 obtained thereby and its detection theoretical lattice resonance half-peak width are generally greater than 10nm, which cannot meet the requirements of high detection accuracy.

[0095] The present application utilizes a nanostamp imprinting method to form a photoresist array 110 on a base layer 1, forms a metal film 120 on the base layer 1 by metal deposition, and through metal deposition and stripping of the metal film 120, forms metal nanoparticles 21 arranged according to preset arrangement rules on the base layer 1 to meet requirements such as shape and size, thereby obtaining an array layer 2 that meets the requirements of high detection accuracy.

[0096] S205: Divide the array layer 2 into a plurality of regions of the same size, and determine the arrangement, size and shape of the holes in the hole mask 300 based on the plurality of regions.

[0097] In the embodiment of the present application, the shape and size of the final multi-gas detection chip 5, the number of first covering layers 3 included on each multi-gas detection chip 5, and the size and thickness of each first covering layer 31 are first determined. According to the position of each first covering layer 31 on the multi-gas detection chip 5 corresponding to the array layer 2, the array layer 2 is divided into multiple regions, and each region includes multiple small blocks. Each first covering layer 31 of each gas detection chip 5 corresponds to a small block in a region, and each region includes the position corresponding to the same first covering layer 31 on all multi-gas detection chips 5. For example, if the final multi-gas detection chip 5 is square and has a size of 1x1 cm2, and needs to be able to detect 4 gases at the same time, the multi-gas detection chip includes 4 layers of the first covering layer 31. The size of each first covering layer 31 is 0.5x0.5 cm2, and the size of the array layer 2 is 10x10 cm2, then the array layer 2 is divided into 4 areas, one area contains 100 small blocks, the first area corresponds to the position of the first layer of the first covering layer 31 of all the 100 multiple gas detection chips 5 finally obtained, the second area corresponds to the position of the second layer of the first covering layer 31 of all the 100 multiple gas detection chips 5 finally obtained, the third area corresponds to the position of the third layer of the first covering layer 31 of all the 100 multiple gas detection chips 5 finally obtained, and the fourth area corresponds to the position of the fourth layer of the first covering layer 31 of all the 100 multiple gas detection chips 5 finally obtained.

[0098] In the embodiment of the present application, after the array layer 2 is divided into a plurality of regions of the same size, the arrangement, size and shape of the holes in the hole mask 300 are determined based on the arrangement of these regions on the array layer 2 .

[0099] As an optional embodiment, the size and shape of the holes in the hole mask 300 are set to be consistent with the size and shape of each area in the multiple areas. In fact, the size and shape of each area in the multiple areas, as well as the size, shape and arrangement of the small blocks in each area are the same, but the arrangement position of each area in all these areas is different. When setting the size and shape of the holes in the hole mask 300, any area can be used as a template for setting. Specifically, the size and shape of a single hole in the hole mask 300 are set to be consistent with the size and shape of the small blocks in the multiple areas, the number of holes in each group is consistent with the number of small blocks in each area, and the arrangement of each group of holes is consistent with the arrangement of the small blocks in one of the multiple areas, so that each group of holes corresponds to the position of each first covering layer 31 in all the multiple gas detection chips 5 finally obtained.

[0100] As an optional embodiment, the hole mask 300 includes only one group of holes. The arrangement position of this group of holes in the hole mask 300 can be consistent with the arrangement position of any one of the multiple areas in the array layer 2. By moving the hole mask 300, the holes thereon can correspond to other areas, thereby forming one layer of the first covering layer 31 on the array layer 2 at a time. By moving the hole mask 300, different first covering layers 31 are formed at different positions of the array layer 2.

[0101] S207 : Based on the hole mask 300 , using different preparation materials, a covering layer 3 that completely covers the multiple regions is formed on the multiple regions, thereby obtaining an initial detection array 4 .

[0102] In the embodiment of the present application, the finally formed covering layer 3 includes multiple layers of first covering layers 31 , and each layer of the first covering layer 31 covers different regions among the multiple regions.

[0103] As an optional implementation, a spray deposition method is used to form a covering layer 3 that completely covers the multiple regions.

[0104] As an optional implementation, each first covering layer 31 is prepared using different raw materials and contains different precursors to form different structures and detect different gases.

[0105] As an optional implementation, step S207: based on the hole mask 300, using different preparation materials, forming a covering layer 3 that completely covers the multiple regions on the multiple regions to obtain the initial detection array 4 may include the following steps:

[0106] S401: Align the hole on the hole mask 300 with one of the multiple regions.

[0107] S403 : Based on the hole mask 300 , spray the prepared raw material onto the array layer 2 to form a first covering layer 31 .

[0108] S405 : moving the hole mask 300 until the hole on the hole mask 300 corresponds to one of the plurality of regions where the first cover layer 31 is not formed.

[0109] S407: Replace the preparation raw materials.

[0110] S409 : Based on the moved hole mask 300 , spray the replaced prepared raw material on the array layer 2 to form a first covering layer 31 .

[0111] Steps S405 to S409 are repeated until a first covering layer 31 is formed on each of the plurality of regions, thereby obtaining an initial detection array.

[0112] Take the formation of four first covering layers 31 on the array layer 2 as an example. Figure 7-Figure 11 As shown, the method of forming the covering layer 3 in the embodiment of the present application is further explained.

[0113] First, the hole in the hole mask 300 corresponds to the first area of ​​the array layer 2, and the raw material is sprayed to form the first first covering layer 311; the hole mask 300 is horizontally translated to the right by the distance of one hole, corresponding to the second area of ​​the array layer 2, and the raw material is replaced and sprayed to form a second first covering layer 312 different from the first first covering layer 311; the hole mask 300 is vertically translated downward by the distance of one hole, corresponding to the third area of ​​the array layer 2, and the raw material is replaced and sprayed to form a third first covering layer 313 different from the previous two first covering layers 31; the hole mask 300 is horizontally translated to the left by the distance of one hole, corresponding to the fourth area of ​​the array layer 2, and the raw material is replaced and sprayed to form a fourth first covering layer 314 different from the previous three first covering layers 31. In this way, a first covering layer 31 is formed in all areas on the array layer 2.

[0114] S209 : Slice the initial detection array 4 to obtain at least one multi-gas detection chip 5 .

[0115] In the embodiment of the present application, the initial detection array 4 is similar to a wafer, on which a plurality of gas detection chips 5 may be included. The above method can form a large-area initial detection array 4 in a single step, and the initial detection array 4 can be sliced ​​to obtain a plurality of gas detection chips 5, thereby preparing a plurality of gas detection chips 5 in a single preparation process, reducing the preparation steps, simplifying the preparation method, and reducing the cost.

[0116] In the embodiment of the present application, each of the multiple gas detection chips 5 finally obtained includes multiple layers of the first covering layer 31, so that the multiple gas detection chip 5 has the ability to detect multiple gases simultaneously and quickly.

[0117] As an optional implementation, after obtaining a plurality of gas detection chips 5, these plurality of gas detection chips 5 are characterized and calibrated. Specifically, a commercial transmission spectrometer is used to detect the surface lattice resonance peak, and by detecting the wavelength and intensity changes of the surface lattice resonance in the transmission spectrum, different regions of the plurality of gas detection chips 5 are detected, and the correlation between the gas concentration and the surface lattice resonance in different regions is established.

[0118] As an optional implementation, the experimental conditions may be further changed to determine the effects of different environmental disturbances (temperature, humidity, etc.) on the surface lattice resonance, thereby optimizing the gas detection results and making the correlation between the gas concentration and the surface lattice resonance more accurate.

[0119] The following takes the preparation of a multi-gas detection chip that can simultaneously detect four different gases as an example to further illustrate the preparation method of the multi-gas detection chip provided by the present application.

[0120] Firstly, the array structure of the array layer 2 is simulated and designed by the finite difference time domain method, and it is determined that the array structure of the particles in the array 2 is silver nanoparticles with a period of 450-600 nm, a diameter of 80-120 nm, and a height of 80-100 nm.

[0121] The photoresist array mold 200 is designed as a polydimethylsiloxane (PDMS) hole array mold with a period of 450-600nm and a diameter of 200-250nm according to the array structure of the array layer 2. The photoresist array mold 200 is used to emboss the photoresist array 110 corresponding to the photoresist array mold 200 on the substrate layer 1, and the photoresist array 110 has a period of 450-600nm and a diameter of 80-150nm.

[0122] A metal film 120 is deposited on the base layer 1 by metal deposition. The material of the metal film 120 is gold, and the thickness of the metal film 120 is 80-150 nm.

[0123] 80-150 nm of silver is deposited on the base layer 1, and the metal film 120 is peeled off to form an array layer 2 on the base layer 1. The array layer 2 is a silver particle lattice with a period of 450-600 nm, a diameter of 80-150 nm, and a height of 80-150 nm.

[0124] The prepared array is placed in a tube furnace at 600-900°C for annealing for 20-60 minutes to optimize the crystal structure and surface shape inside the array layer 2.

[0125] A hole mask plate 300 with a hole size of 0.5 x 0.5 cm2 is used to spray-deposit the first covering layer 31 in the first area. The hole mask plate 300 is moved horizontally to the right, the preparation material is changed, and the first covering layer 31 is spray-deposited in the second area. The hole mask plate 300 is moved vertically downward, the preparation material is changed, and the first covering layer 31 is spray-deposited in the third area. The hole mask plate 300 is moved horizontally to the left, the preparation material is changed, and the first covering layer 31 is spray-deposited in the third area. In this way, the spraying deposition of four layers of the first covering layer 31 is completed, and the initial detection array 4 is obtained.

[0126] Finally, the initial detection array 4 is sliced ​​into individual chips of 1×1 cm 2 to obtain a plurality of multi-gas detection chips 5 capable of simultaneously detecting four different gases.

[0127] The multiple gas detection chip disclosed in the present application includes a base layer, an array layer and a multi-layer covering layer; the array layer is arranged on the base layer, and the array layer is composed of multiple metal nanoparticles arranged according to a preset arrangement rule; the covering layer is arranged on the array layer; the covering layer includes multiple first covering layers, and the multiple first covering layers respectively cover different areas of the array layer, and the multiple first covering layers completely cover the array layer. In this way, the obtained multiple gas detection chip has the advantages of high selectivity, high detection sensitivity, small size, easy integration, and the ability to quickly detect multiple gases simultaneously.

[0128] The above description is only an optional embodiment of the present application and is not intended to limit the present application. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present application should be included in the protection scope of the present application.

Claims

1. A method for preparing a multi-gas detection chip, characterized in that: The method comprises: Determining a preset arrangement rule, size and shape of a plurality of metal nanoparticles (21) in an array layer (2); Based on the preset arrangement rules, sizes and shapes of the plurality of metal nanoparticles (21), forming a photoresist array (110) on the base layer (1); forming a metal film (120) on the base layer (1) based on the photoresist array (110); forming the array layer (2) on the base layer (1) based on the metal film (120); peeling the metal film (120) from the base layer (1); Dividing the array layer (2) into a plurality of regions of the same size, and determining the arrangement, size and shape of the holes in the hole mask (300) based on the plurality of regions; Based on the hole mask (300), different preparation materials are used to form a covering layer (3) that completely covers the multiple regions on the multiple regions, thereby obtaining an initial detection array (4); the method for forming the covering layer (3) that completely covers the multiple regions on the multiple regions is spray deposition; the covering layer (3) is a metal organic framework; the covering layer (3) includes multiple first covering layers (31); the multiple first covering layers (31) respectively cover different regions among the multiple regions; Slicing the initial detection array (4) to obtain at least one multi-gas detection chip (5); each of the multi-gas detection chips (5) comprises the multi-layer first covering layer (31); Wherein, based on the hole mask (300), using different preparation materials, forming a covering layer (3) on the multiple regions that completely covers the multiple regions, and obtaining an initial detection array (4), comprises: Aligning the hole on the hole mask (300) with one of the multiple areas; Based on the hole mask (300), spraying the prepared raw material on the array layer (2) to form a first covering layer (31); Moving the hole mask (300) until the hole on the hole mask (300) corresponds to one of the multiple regions where the first covering layer (31) is not formed; Replacing the preparation raw materials; Based on the moved hole mask (300), spraying the replaced preparation raw material on the array layer (2) to form a first covering layer (31); Repeating the steps of: moving the hole mask (300) until the hole on the hole mask (300) corresponds to one of the multiple regions where the first covering layer (31) is not formed; replacing the preparation raw material; based on the moved hole mask (300), spraying the replaced preparation raw material on the array layer (2) to form a first covering layer (31); until a first covering layer (31) is formed on each of the multiple regions, thereby obtaining the initial detection array (4).

2. The method for preparing a multi-gas detection chip according to claim 1, characterized in that: The method for determining the preset arrangement rule, size and shape of the plurality of metal nanoparticles (21) in the array layer (2) is a finite difference time domain method.

3. The method for preparing a multi-gas detection chip according to claim 1, characterized in that: The method of forming a photoresist array (110) on a base layer (1) based on a preset arrangement rule, size and shape of the plurality of metal nanoparticles (21) comprises: Designing a photoresist array mold (200) based on a preset arrangement rule, size and shape of the plurality of metal nanoparticles (21); The photoresist array (110) is formed by embossing the photoresist array mold (200) on the base layer (1).

4. The method for preparing a multi-gas detection chip according to claim 1, characterized in that: The step of determining the arrangement, size and shape of the holes in the hole mask (300) based on the plurality of regions comprises: Determining that the size and shape of the holes in the hole mask (300) are consistent with the size and shape of each of the multiple regions; Determining that the arrangement of the holes in the hole mask (300) is consistent with the arrangement position of one of the multiple regions in the array layer (2); The array layer (2) is arranged on the base layer (1), and the array layer (2) is composed of a plurality of metal nanoparticles (21) arranged according to a preset arrangement rule; The covering layer (3) is arranged on the array layer (2); the covering layer (3) comprises a plurality of first covering layers (31); the plurality of first covering layers (31) respectively cover different areas of the array layer (2), and the plurality of first covering layers (31) completely cover the array layer (2).

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