Plasmon enhanced nanocone structure and preparation method and application thereof

Abstract

The invention provides a plasmon enhanced nanocone structure for detecting micro-nano plastics and other pollutants as well as a preparation method and application of the plasmon enhanced nanocone structure. The plasmon enhanced nanocone structure is structurally represented as a gold-silver nanoparticle bimetal hollow nanostructure (BHNC-Au / Ag). The structure can achieve physical enhancement up to 1.1 * 108, as well as self-build enrichment of target hierarchical analytes for size-matched hot spot regions. Layered hotspots (DSHSs, DVHSs, and LHSs) within the structure are determined to promote enrichment of the target contaminants in the optimal hotspot region to perform high sensitivity detection of micro-nano plastics (as low as 10 <-8 > g / L), small molecules (as low as 10 <-13 > M), and SARS-CoV-2S proteins (as low as 10 <-9 > M) over typical geometric dimensions. According to the technical scheme provided by the invention, a practical solution is provided for trace detection of layered micro-nano plastic and other mixed water pollutants.

Description

Technical Field

[0001] The invention relates to the technical field of surface enhanced Raman scattering detection, and in particular to a plasmon enhanced nanocone structure, which is structurally a three-dimensional gold-silver nano hollow cone structure. Background Art

[0002] In recent years, plastic exposure has become one of the most pressing safety risks facing modern human society, with impacts covering environmental health, ecosystem stability, and human daily life. Among them, micro-nano plastics have become the focus of research and regulation due to their special properties and wide distribution. Micro-nano plastics have layered geometric sizes from nanometers to micrometers, as well as extremely large specific volumes and specific surface areas, making them ideal carriers of harmful substances such as viruses and bacteria, posing a potential threat to human health and ecological environment stability. More importantly, in diverse water environments, these plastic residues often exhibit complex particle size distribution characteristics. At the same time, due to the stability of their chemical properties and the inertness of their physical properties, it is greatly difficult to detect them quickly and effectively.

[0003] In this context, the introduction of plasmonic nanostructures provides a new path for surface enhanced Raman scattering (SERS) technology. SERS technology relies on the localized surface plasmon resonance effect generated by plasmonic nanostructures to greatly enhance the Raman scattering signal of the analyte. At the same time, with the development of three-dimensional (3D) plasmonic nanostructures in recent years, its detection capability has been further improved due to its high-density three-dimensional hotspot distribution and flexibility in spectral manipulation. This 3D structure has demonstrated powerful detection capabilities in the fields of solar steam generation, water purification, and plasmonic optical monitoring. However, when it comes to large-scale layered targets, such as micro-nano plastic pollutants in water, there are still many challenges in using plasmonic SERS (surface enhanced Raman scattering) technology for detection. Due to their wide range of particle sizes, micro-nano plastics often have spatial inconsistencies when matching with hotspot areas, which greatly limits the sensitivity and accuracy of detection. The patent with publication number CN2020104136608 provides a gold-silver nanocone array with volume-enhanced Raman scattering effect. The gold-silver nanocone array is made by multiple anodization and wet etching, and then coated with gold thin film and silver thin film. However, the gold-silver nanocone array structure has a narrow detection range for target identification objects and cannot achieve high detection accuracy, which limits the efficient identification and precise analysis of multi-size and multi-level complex targets. Summary of the invention

[0004] In order to make up for the deficiencies of the prior art, the present invention provides a plasmon-enhanced nanocone structure, which is a three-dimensional gold-silver nano-hollow cone structure. The plasmon-enhanced nanocone structure is prepared by depositing a gold film on a template having a V-shaped nanopore structure, removing the template by etching to obtain a V-shaped nanocone structure deposited with a gold film, and then depositing a silver film on the V-shaped nanocone structure deposited with a gold film to obtain a plasmon-enhanced nanocone structure; The thickness of the gold film in the plasmon-enhanced nanocone structure is 200-300 nm, and the thickness of the silver film is 20-40 nm; the pore size of the plasmon-enhanced nanocone structure is 10-30 nm; Preferably, the thickness of the gold film in the plasmon-enhanced nanocone structure is 250 nm, and the thickness of the silver film is 30 nm; the pore size of the plasmon-enhanced nanocone structure is 20 nm.

[0005] The thickness of the gold film is 200-300 nm, the thickness of the silver film is 20-40 nm, and the pore size of the nanocone structure is 10-30 nm. The pore refers to the hole structure on the surface of the nanocone.

[0006] Preferably, the template having a V-shaped nanopore structure is selected from an anodized aluminum template, a porous silicon template or a titanium oxide nanotube array template having a V-shaped nanopore structure; the maximum pore diameter of the V-shaped nanopore is 400-500 nm and the pore depth is 800-1000 nm.

[0007] Preferably, the gold thin film is produced by electron beam vapor deposition technology; and the silver thin film is produced by magnetron sputtering technology.

[0008] Preferably, the thickness of the gold film is 250 nm, the thickness of the silver film is 30 nm, and the pore size of the nanocone structure is 20 nm.

[0009] The present invention also provides a method for preparing a plasmon-enhanced nanocone structure, the preparation steps being: Step 1, taking a template with a V-shaped nanopore structure and performing cleaning pretreatment; after drying, depositing a gold film on the template with the V-shaped nanopore structure using electron beam vapor deposition technology; Step 2, etching and demolding the product obtained in step 1 to obtain a conical gold nanostructure; Step 3, depositing a silver film on the surface of the conical gold nanostructure obtained in step 2 by using magnetron sputtering technology.

[0010] Preferably, the template with the V-shaped nanopore structure in step 1 adopts one of an anodized aluminum template, a porous silicon template or a titanium oxide nanotube array template with a V-shaped nanopore structure; the anodized aluminum template with the V-shaped nanopore structure contains periodically arranged V-shaped nanopores, and the maximum pore diameter of the V-shaped nanopores is 400~500 nm and the pore depth is 800~1000 nm.

[0011] Preferably, the conditions of the electron beam vapor deposition technology in step 1 are: placing the template with a V-shaped nanopore structure and the gold target in a vacuum deposition chamber of an electron beam vapor deposition apparatus, and adjusting the gas pressure in the vacuum deposition chamber to 5×10 -4 ~ 9×10 - 4 Pa, and a 200~300 nm gold film was deposited on the V-shaped AAO template at a rate of 20~40 nm / min.

[0012] Preferably, the conditions of the magnetron sputtering technology in step 3 are as follows: the conical gold nanostructure and the silver target obtained in step 2 are placed in a vacuum deposition chamber of a magnetron sputtering apparatus, an inert gas is introduced and the gas pressure of the vacuum deposition chamber is adjusted to 5×10 -4 ~ 9×10 -4 Pa, set the sputtering power to 40-60 W, the coating time to 10-30 min, and the thickness of the deposited silver film to 20-40 nm.

[0013] An application of a plasmon-enhanced nanocone structure obtained according to the technical solution provided by the present invention, wherein the plasmon-enhanced nanocone structure is applied to SERS detection of layered micro-nanoscale pollutants.

[0014] Preferably, the plasmon-enhanced nanocone structure is applied to SERS detection of drug molecules, dye molecules, virus particles and micro-nano plastic pollutants.

[0015] Beneficial Effects The present invention proposes a plasmon-enhanced nanocone structure for detecting micro-nano plastics and other pollutants, and its preparation method and application. The plasmon-enhanced nanocone structure is structurally a gold-silver nanoparticle bimetallic hollow nanostructure (BHNC-Au / Ag). The plasmon-enhanced nanocone structure rationally integrates high-density surface and volume hotspots into one structure. The bimetallic nanoparticles are closely arranged in a V-shaped manner and have a large number of nano-voids in the lateral and longitudinal regions. The hierarchical hotspots (DSHSs, DVHSs and LHSs) within the structure are determined to promote the enrichment of target pollutants in the optimal hotspot area, thereby detecting micro-nano plastics smaller than 5 microns (as low as 10 -8 g / L), small molecules (as low as 10 -13M) and SARS-CoV-2 S protein (as low as 10 -9 M) for high-sensitivity detection.

[0016] The plasmon-enhanced nanocone structure provided by the present invention can achieve a high efficiency of 1.1×10 8 Physical enhancement; self-constructed enrichment of target stratified analytes in size-matched hotspots, not only can detect concentrations as low as 10 -8 g / L of micro-nano plastics, and can also simultaneously detect a wide range of pollutants other than micro-nano plastics, such as drug molecules, dye molecules, virus particles, etc.

[0017] The technical solution provided by the present invention provides a practical solution for the trace detection of layered micro-nano plastics and other mixed water pollutants. On the one hand, it can generate high-performance SERS signals, and on the other hand, this structure can also well adjust the far-field scattering curve, thereby significantly improving the collection efficiency of SERS signals and further improving the detection limit, providing a practical way for ultra-sensitive detection of complex micro-nano pollutants with heterogeneous sizes and / or compositions. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 A schematic diagram of the BHNC provided by the present invention; Figure 2 (ab) are three-dimensional top views of the structure of the product obtained in Example 1 (i.e., BHNC-Au / Ag-1); Figure 2 (cd) are three-dimensional cross-sectional SEM images of the product obtained in Example 1 (i.e., BHNC-Au / Ag-1); Figure 2 (ef) is the EDS element map of the structure of the product obtained in Example 1 (i.e., BHNC-Au / Ag-1); Figure 3 Far-field radiation diagrams of the products obtained for Example 1 and Examples 8-10, and all the diagrams are normalized for comparison; Figure 4 The maximum hot spot intensity of the products obtained in Example 1 and Examples 8-9, corresponding to the detection of small drug molecules (MNZ drug molecules), SARS-CoV-2S protein and nanoplastics in the samples, respectively; Figure 5 1000 cm of 30, 50, 100, 300, 500 and 1000 nm PS nanoplastic solutions with different concentrations −1 strength. DETAILED DESCRIPTION

[0019] In order to explain the technical content, structural features, achieved objectives and effects of the technical solution in detail, the following is a detailed description in conjunction with specific embodiments and accompanying drawings.

[0020] Example 1 Step 1, selecting an anodized aluminum template with a V-shaped nanopore structure (referred to as V-shaped AAO template), and performing a cleaning and drying pretreatment to remove contaminants on the template surface; The macroscopic size of the selected V-shaped AAO template is 2*2 cm; the selected V-shaped AAO template has a plurality of periodically arranged V-shaped nanopores, the pore diameter (the widest dimension of the nanopore) of the V-shaped nanopore is 450 nm, and the pore depth is 900 nm; Step 2, depositing a gold film on the V-shaped AAO template using electron beam vapor deposition (PVD) technology; The specific operation is as follows: take a clean and dry V-shaped AAO template and a gold target and place them in the vacuum deposition chamber of an electron beam vapor deposition apparatus, and adjust the pressure of the vacuum deposition chamber to 8.0×10 -4 Pa, a 250 nm gold film was deposited on the V-shaped AAO template at a rate of 30 nm / min; Step 3, using a sodium hydroxide solution to perform an etching and demolding treatment on the product obtained in step 2 to obtain a conical gold nanostructure after etching; The specific operation is as follows: prepare a sodium hydroxide solution with a concentration of 0.1 mol / L, immerse the V-shaped AAO template obtained in step 2 in the sodium hydroxide solution for etching and demolding; after the demolding is completed, use filter paper to take out the etched conical gold nanostructure from the solution, wash it with deionized water to remove the residual sodium hydroxide solution, and dry it for later use; Step 4, depositing a silver film on the surface of the conical gold nanostructure using magnetron sputtering technology; The specific operation is as follows: the conical gold nanostructure and silver target obtained in step 3 are cleaned and dried and placed in the vacuum deposition chamber of the magnetron sputtering apparatus, argon gas is introduced and the pressure of the vacuum deposition chamber is adjusted to 8.0×10 -4 Pa, set the sputtering power to 50 W, and the coating time to 10-15 min to obtain a three-dimensional gold-silver nano-hollow cone network, wherein the gap size of the three-dimensional gold-silver nano-hollow cone network is 20 nm. Labeled as BHNC-Au / Ag-1.

[0021] Example 2 The same preparation method as in Example 1 was used, except that the pressure of the vacuum deposition chamber was adjusted to 5.0×10 -4 Pa, and a 300 nm gold film was deposited at a rate of 40 nm / min. The obtained product was labeled as BHNC-Au / Ag-2.

[0022] Example 3 The same preparation method as in Example 1 was used, except that the pressure of the vacuum deposition chamber was adjusted to 9.0×10 -4 Pa, and a 200 nm gold film was deposited at a rate of 20 nm / min. The obtained product was labeled as BHNC-Au / Ag-3.

[0023] Example 4 The same preparation method as in Example 1 was used, except that the pressure of the vacuum deposition chamber was adjusted to 5.0×10 -4 Pa, the sputtering power was set to 40 W, the coating time was 10 min, and the thickness of the silver film was 20 nm. The obtained product was labeled as BHNC-Au / Ag-4.

[0024] Example 5 The same preparation method as in Example 1 was used, except that the pressure of the vacuum deposition chamber was adjusted to 9.0×10 -4 Pa, the sputtering power was set to 60 W, the coating time was 30 min, and the thickness of the silver film was 40 nm. The obtained product was labeled as BHNC-Au / Ag-5.

[0025] Example 6 The same preparation method as in Example 1 was used, except that the gap size of the hollow cone structure was 10 nm. The obtained product was labeled as BHNC-Au / Ag-6.

[0026] Example 7 The same preparation method as in Example 1 was used, except that the gap size of the hollow cone structure was 30 nm. The obtained product was labeled as BHNC-Au / Ag-7.

[0027] Example 8 The same preparation method as in Example 1 was used, except that the preparation steps did not include step 4. The obtained product was labeled as HNC-Au.

[0028] Example 9 The same preparation method as in Example 1 was used, except that step 4 used the same preparation process as step 2 to deposit two layers of Au thin films. The obtained product was labeled HNC-Au-2.

[0029] Example 10 The same preparation method as in Example 1 was used, except that the template material was a common planar plate-shaped structural material (without a V-shaped nanopore structure). The obtained product was labeled as P-Au / Ag.

[0030] Embodiment 11 The same preparation method as in Example 1 is adopted, except that the template having a V-shaped nanopore structure is selected from a porous silicon template having a V-shaped nanopore structure; the maximum pore diameter of the V-shaped nanopore is 400-500 nm, and the pore depth is 800-1000 nm.

[0031] Example 12 The same preparation method as in Example 1 is adopted, except that the template having a V-shaped nanopore structure is selected from a titanium oxide nanotube array template having a V-shaped nanopore structure; the maximum pore diameter of the V-shaped nanopore is 400-500 nm and the pore depth is 800-1000 nm.

[0032] The BHNC-Au / Ag structure provided by the present invention can realize high-precision SERS detection of micro-nano plastics. Figures 1 to 5 The structure and mechanism of action of a gold-silver nanoparticle bimetallic hollow nanostructure (BHNC-Au / Ag) provided by the present invention are described and introduced. The following combination Figure 1 The structure and function of BHNC-Au / Ag structure are described as follows: Surface enhanced Raman scattering (SERS) detection technology is a highly sensitive spectral detection technology that significantly enhances the Raman scattering signal on the surface of metal nanostructures to achieve detection of trace substances and even single-molecule levels. The enhancement mechanisms of SERS detection mainly include electromagnetic enhancement and chemical enhancement, which rely on the localized surface plasmon resonance effect of the metal surface and the chemical interaction between molecules and the metal surface, respectively. In order to achieve efficient SERS detection of water-soluble layered micro-nano pollutants with poor optical detectability and low concentration, the BHNC-Au / Ag structure provided by the present invention improves the SERS detection efficiency through three physical enhancement mechanisms.

[0033] 1. Plasmon resonance effect enhancement mechanism The BHNC-Au / Ag structure provided by the present invention is designed with a multi-level hierarchical structure on a scale from nanometer to micrometer, which can form a hierarchical high-density local hot spot area. The hot spot area generates a strong local electromagnetic field through the plasmon resonance effect, which can significantly enhance the Raman scattering signal, thereby effectively capturing micro-nano pollutant particles of different sizes and shapes in the contaminated water sample.

[0034] 2. Tip effect and interface force enhancement mechanism Concentration and size-matching optimization of layered pollutants. The hollow cone design in the BHNC-Au / Ag structure not only has a large specific surface area and unique geometric properties, but also effectively concentrates the layered pollutants into size-matched hot spots through its tip effect and interfacial forces. Layered pollutants are strongly coupled with the electromagnetic field here, greatly improving the Raman scattering signal intensity of the target molecules. In particular, for complex pollutants such as micro-nano plastics, the multi-level interactions of their heterogeneous surfaces can further enhance the signal and ensure the sensitivity and accuracy of detection.

[0035] 3. Mechanism of directional backscattering enhancement in a wide spectral range In order to improve the overall detection efficiency, the BHNC-Au / Ag design pays special attention to optimizing its optical properties, including the directionality of backlight scattering and wide spectrum enhancement performance. The heterogeneous interface and multi-level hot spot distribution of the hollow conical bimetallic structure can not only capture more incident light energy, but also effectively guide the scattered light into the detection system. This directional light scattering design reduces the interference of background noise while maintaining strong signal intensity, thereby improving the signal-to-noise ratio and detection reliability.

[0036] Figure 1The schematic diagram of the BHNC-Au / Ag structure provided by the present invention forms a tightly packed network by self-assembling bimetallic proton nanoparticles (Au and Ag nanoparticles) in the vertical direction. This self-assembly characteristic can not only construct a high-density hot spot area in three-dimensional space, but also distribute hot spots in different host areas (such as particle interfaces, gaps and tip parts), thereby significantly enhancing the local electromagnetic field intensity. Due to the three-dimensional distribution characteristics of the hot spots, the BHNC-Au / Ag substrate shows excellent efficiency in capturing and enhancing the target pollutant signal, especially for the multi-scale detection capability of layered pollutants. Secondly, the nanoparticles of BHNC-Au / Ag form a highly regular hierarchical V-shaped profile structure through self-assembly. The geometric design of the V-shaped profile can effectively guide the propagation direction of light, so that more scattered light enters the detection channel, thereby improving the signal-to-noise ratio of the detection system. This geometric structure can also achieve precise control of the hot spot distribution and intensity by adjusting the V-shaped angle, the layer spacing and the particle size, further enhancing the enhancement effect. This property makes BHNC-Au / Ag very suitable for the detection of a wide range of pollutants, especially showing excellent performance in a wide spectral range. In addition to the above two key features, the BHNC-Au / Ag structure also has a unique hierarchical capture mechanism. The multi-level hotspot areas formed by nanoparticles can effectively distinguish pollutants of different sizes and gather them into hotspot areas of matching size. For example, as small as drug molecules (sub-nanometer) or virus particles (tens of nanometers), as large as micro-nano plastic pollutants (size range of 30 nm -5 μm) can be concentrated in the corresponding hotspot areas, thereby achieving accurate detection of targets of different sizes. This multi-scale hierarchical capture and enhancement characteristics further broadens the scope of application of BHNC-Au / Ag in practical applications.

[0037] The following combination Figures 2~5 The performance and mechanism of action of a gold-silver nanoparticle bimetallic hollow nanostructure (BHNC-Au / Ag) provided by the present invention are described in the test example: Test Example 1 The samples obtained in Example 1 were fully characterized by scanning electron microscopy (SEM) and energy dispersive X-ray spectroscopy (EDS). Figure 2 (af) shown. Figure 2 (ab) are three-dimensional top-down SEM images of the sample structure; Figure 2 (cd) are three-dimensional cross-sectional SEM images of the samples; Figure 2 (ef) are EDS element maps of metallic gold (Au) and silver (Ag) on ​​the samples.

[0038] SEM images (such as Figure 2ad) show that the three-dimensional self-assembled bimetallic nanoparticles are closely packed in the hollow nanocone structure, forming nanometer-sized gaps. These gaps provide ideal sites for the generation of local hot spots (LHS), and their three-dimensional geometric layered characteristics further enhance the distribution density of hot spots. The cross-sectional SEM images reveal the fine structure of high-density gold nanoparticles (Au-NPs) in BHNC-Au / Ag and the underlying connected gold film, verifying the mechanical stability of the porous nanocone structure and the high efficiency of self-assembly.

[0039] EDS element diagram ( Figure 2 e-f) show the uniform distribution of metallic gold (Au) and silver (Ag) within the nanocones, verifying the compositional uniformity of the structure and the precision of the preparation process.

[0040] In summary Figure 2 The structural characteristics of BHNC-Au / Ag show its superior optical properties. The three-dimensional porous nanocones not only effectively enhance the interaction between light and matter, but also show excellent performance in the regulation of plasmon working bandwidth and the optimization of backscattering response. This structure can precisely control the gap size of the nanocones by adjusting the PVD conditions, providing an efficient physical channel for the enrichment of target molecules. In the experiments shown in this article, the average gap size of the prepared BHNC-Au / Ag structure is about 20 nm. This optimized gap helps to capture and enrich ultra-low concentration pollutants at the target hotspot location, thereby achieving high-sensitivity SERS detection of them.

[0041] Test Example 2 The three-dimensional finite difference-time domain (FDTD) method was used to test the SERS performance of the samples prepared in Example 1 and Examples 8-10. The three-dimensional finite difference-time domain (FDTD) method was used to calculate the far-field direction-dependent backscattering pattern. A nanoplastic particle was placed in the center area of ​​these structures in the calculation. The test results are as follows: Figure 3 shown.

[0042] like Figure 3 As shown in the figure, the Raman scattering angle of the P-Au / Ag structure is within the range of ±82°, which greatly exceeds the collection angle of commonly used Raman instruments, while the HNC structure is consistent with the collection angle. Among them, the BHNC-Au / Ag structure performs best, with a Raman backscattering angle of ±39° and a collection efficiency 1.2 times that of the P-Au / Ag structure. The above proves the ability of the BHNC structure to collimate Raman scattered light.

[0043] At the same time, finite element method (FEM) calculations also proved the advantages of BHNC structure in near-field SERS enhancement. The test objects included small and medium drug molecules (MNZ), SARS-CoV-2S protein and nanoplastics. The test results are as follows Figure 4shown.

[0044] Figure 4 The calculated electric field distribution of the samples prepared in Examples 1 and 8-9 under 532 nm excitation is shown. The electric field distribution of BHNC-Au / Ag shows effective light confinement in the hollow cavity. The maximum local field intensity enhancement E max / E 0 is 106.3. It is noteworthy that three different hot spots are found: the bimetallic hot spot region (DSHSs) located at the top, the vertical hot spot region (DVHSs) in the cavity, and the local hot spot region (LHSs) on the surface of the nanoparticles. Among them, the generation of DSHSs and DVHSs can be attributed to the light field coupling in the cavity, which is promoted by the backscattering generated by the interaction of the connected gold film with gold oxide and silver oxide. In contrast, the LHS generated by the curved surface of the nanoparticles on the inner wall and bottom of the structure mainly originates from the near-field coupling between adjacent high-density gold nanoparticles (Au-NPs) and high-density silver nanoparticles (Ag-NPs) and the connected gold film. Layered pollutants ranging from nanometers to micrometers are deposited on different hot spots, so their SERS signals can be enhanced. In contrast, the light confinement of the HNC-Au-2 structure is poor. Due to the severe light leakage phenomenon, a large number of DVHSs regions are generated, and most layered plastic particles cannot enter these regions. By increasing the thickness of gold deposition in the inner cavity region and on the surface to 250 nm, the light confinement can be significantly enhanced, but it is still weaker than that of HNC-Au / Ag.

[0045] Test Example 3 The performance of the sample structure prepared in Example 1 was systematically characterized using the standard SERS detection procedure. The test objects were 1000 cm-1 of 30, 50, 100, 300, 500 and 1000 nm PS micro-nano plastic solutions at different concentrations. −1 Strength, test results such as Figure 5 shown.

[0046] Figure 5 It shows that hierarchical micro-nanoplastics with a distribution range of 30 nm-5 μm can be detected even at extremely low concentrations (10⁻ 8g / L), which fully demonstrates the unique advantages of BHNC structure in trace pollutant detection. Detailed scanning electron microscopy (SEM) analysis further reveals the key role of the three-dimensional hotspot areas of the BHNC-Au / Ag structure in capturing hierarchical micro-nano plastic particles. The study found that micro-nano plastics with a size larger than 450 nm are mainly enriched on the surface of the BHNC structure, and their Raman signals are significantly enhanced by the bimetallic hotspot areas (DSHSs) distributed on the top. For plastic particles with a size smaller than 450 nm, they tend to be preferentially concentrated inside the cavity of the BHNC structure due to water pressure. These particles further interact with the high-density nanogaps between the bimetallic nanoparticles in the cavity, and their Raman signals are significantly enhanced through the vertical hotspot areas (DVHSs) in the cavity and the local hotspot areas (LHSs) on the surface of the nanoparticles. This hierarchical enrichment and enhancement mechanism not only ensures the comprehensive detection of pollutants of different scales, but also shows the broad application prospects of the BHNC structure in the field of environmental monitoring.

[0047] It should be noted that, although the above embodiments have been described in this article, the patent protection scope of the present invention is not limited thereby. Therefore, based on the innovative concept of the present invention, changes and modifications made to the embodiments described herein, or equivalent structures or equivalent process changes made using the contents of the present invention specification and drawings, directly or indirectly applying the above technical solutions to other related technical fields, are all included in the patent protection scope of the present invention.

Claims

1. A plasmon-enhanced nanocone structure, characterized in that: The plasmon-enhanced nanocone structure is prepared by depositing a gold film on a template having a V-shaped nanopore structure, removing the template by etching to obtain a V-shaped nanocone structure deposited with the gold film, and then depositing a silver film on the V-shaped nanocone structure deposited with the gold film to obtain the plasmon-enhanced nanocone structure.

2. The plasmon-enhanced nanocone structure according to claim 1, characterized in that: The maximum pore size of the V-shaped nanopore structure is 400-500 nm, and the pore depth is 800-1000 nm; the template is selected from one of an anodic aluminum oxide template, a porous silicon template or a titanium oxide nanotube array template.

3. The plasmon-enhanced nanocone structure according to claim 1, characterized in that: The gold thin film was deposited by electron beam vapor deposition technique; the silver thin film was deposited by magnetron sputtering technique.

4. The plasmon-enhanced nanocone structure according to claim 1, characterized in that: The thickness of the gold film in the plasmon-enhanced nanocone structure is 200-300 nm, and the thickness of the silver film is 20-40 nm; the pore size of the plasmon-enhanced nanocone structure is 10-30 nm; Preferably, the thickness of the gold film in the plasmon-enhanced nanocone structure is 250 nm, and the thickness of the silver film is 30 nm; the pore size of the plasmon-enhanced nanocone structure is 20 nm.

5. A method for preparing a plasmon-enhanced nanocone structure, characterized in that: The preparation method comprises the following steps: Step 1, depositing a gold film on a template having a V-shaped nanopore structure using electron beam vapor deposition technology; Step 2, etching and demolding the product obtained in step 1 to obtain a conical gold nanostructure; Step 3, using magnetron sputtering technology to deposit a silver film on the conical gold nanostructure obtained in step 2 to obtain a plasmon-enhanced nanocone structure.

6. The preparation method according to claim 5, characterized in that: The maximum pore size of the V-shaped nanopore structure in step 1 is 400-500 nm, and the pore depth is 800-1000 nm; the template is selected from one of an anodized aluminum template, a porous silicon template, or a titanium oxide nanotube array template.

7. The preparation method according to claim 5, characterized in that: In step 1, the electron beam vapor deposition technology is to place the template with V-shaped nanopore structure and the gold target in the vacuum deposition chamber of the electron beam vapor deposition instrument to deposit the gold film; the pressure of the vacuum deposition chamber is 5×10 -4 ~ 9×10 -4 Pa, and the deposition rate is 20~40 nm / min.

8. The preparation method according to claim 5, characterized in that: In step 3, the magnetron sputtering technique is to place the conical gold nanostructure and the silver target obtained in step 2 in the vacuum deposition chamber of the magnetron sputtering instrument, and introduce inert gas to deposit the silver film; the pressure of the vacuum deposition chamber is 5×10 -4 ~ 9×10 -4 Pa, the sputtering power is 40~60 W, and the deposition time is 10~30 min.

9. The plasmon-enhanced nanocone structure according to any one of claims 1 to 4 or the plasmon-enhanced nanocone structure prepared by the preparation method according to any one of claims 5 to 8 is applied to SERS detection of layered micro-nanoscale pollutants.

10. The use according to claim 9, characterized in that: The plasmon-enhanced nanocone structure is used for SERS detection of drug molecules, dye molecules, virus particles and micro-nano plastic pollutants.

Images