CN113848199B - Method for preparing gold-silver alloy annular nanostructure substrate - Google Patents

Abstract

The application relates to a method for preparing a gold-silver alloy annular nanostructure substrate, in particular to the field of nanostructure substrate preparation. The method provided by the application comprises: mixing the prefabricated gold-silver alloy nanoparticle colloidal suspension and cyclohexane in a container; injecting the ethanol solution into the container, so that the gold-silver alloy nanoparticle and the aqueous solution and the cyclohexane The contact angle of the interface is close to 90 degrees, so that the gold-silver alloy nanoparticles form a thin film of gold-silver alloy nanoparticles on the interface between the aqueous solution and cyclohexane, and the cyclohexane is taken out of the container; Pick up the gold-silver alloy nanoparticle film at the bottom, and dry it for the first preset time to obtain a gold-silver alloy annular nanostructure substrate, wherein, the preset substrate surface is provided with a plurality of nanoholes; the preset detection molecule It is arranged on the surface of the gold-silver alloy annular nanostructure substrate.

Description

Method for preparing gold-silver alloy annular nanostructure substrate

technical field

The present application relates to the field of nanostructure substrate preparation, in particular to a method for preparing a gold-silver alloy annular nanostructure substrate.

Background technique

Surface-enhanced Raman scattering (SERS) technology is one of the typical applications of enhanced Raman spectroscopy. The localized surface plasmon resonance (LSPR) formed by the subwavelength nanostructured SERS substrate under the excitation of an external field causes the localized electromagnetic field of the substrate to be enhanced. , resulting in a significant enhancement of the Raman signal of the detection molecules adsorbed on the SERS substrate. In recent years, surface-enhanced Raman scattering technology has been widely used in food safety, drug detection, biosensing, water quality monitoring, medical research and other fields due to its high sensitivity, short time-consuming, label-free and chemical specificity.

The surface-enhanced Raman scattering technology depends on the morphology of the substrate. The metal ring nanostructure substrate has strong local field coupling between the metal nanostructure gaps, forming a strong electromagnetic field enhancement, and realizing high detection of molecular Raman signals. Sensitive detection. However, the detection molecules are randomly adsorbed on the substrate surface, and only the molecules trapped in the hot spots can be effectively detected.

In the prior art, in the preparation process of the metal annular nanostructure substrate, a large-area, regular annular nanostructure substrate is fabricated to accurately calibrate and measure target molecules. Common top-down preparation technologies include photolithography, ion beam, and electron beam. Due to the disadvantages of high preparation cost, harsh conditions, and low yield, the large-scale application of the above technologies is limited to a certain extent.

Contents of the invention

The purpose of the present invention is to, aiming at the deficiencies in the above-mentioned prior art, provide a kind of method for preparing gold-silver alloy annular nanostructure substrate, to solve the problem in the preparation process of metal annular nanostructure substrate in the prior art , to fabricate large-area, regular annular nanostructured substrates to accurately calibrate and measure target molecules. Common top-down preparation technologies include photolithography, ion beam, and electron beam. Due to the disadvantages of high preparation cost, harsh conditions, and low yield, the large-scale application of the above technologies is limited to a certain extent.

In order to achieve the above object, the technical solution adopted in the embodiment of the present invention is as follows:

In a first aspect, the present application provides a method for preparing a gold-silver alloy annular nanostructure substrate, the method comprising:

Mixing the prefabricated gold-silver alloy nanoparticle colloidal suspension with cyclohexane and setting it in the container;

The ethanol solution is injected into the container, so that the gold-silver alloy nanoparticles are captured by the interface between the aqueous solution and the cyclohexane to form a gold-silver alloy nanoparticle film, and the cyclohexane is taken out of the container;

Picking up the gold-silver alloy nanoparticle film using a preset substrate, and drying for a first preset time to obtain a gold-silver alloy annular nanostructure substrate, wherein the surface of the preset substrate is provided with a plurality of nanoholes;

The preset detection molecules are arranged on the surface of the gold-silver alloy ring nanostructure substrate.

Optionally, the gold-silver alloy nanoparticle film is picked up using the preset substrate, and dried for the first preset time, and the step of obtaining the gold-silver alloy annular nanostructure substrate also includes:

Cut the preset substrate according to the size of the electrolytic cell;

Use acetone solution, ethanol solution, deionized water to clean the preset substrate;

The predetermined substrate is placed on the anode of the electrolytic cell, a polishing solution is injected into the electrolytic cell, and the predetermined substrate is polished under the condition of an ice bath.

Optionally, the step of placing the predetermined substrate on the anode of the electrolytic cell, injecting the polishing solution into the electrolytic cell, and polishing the predetermined substrate under ice bath conditions also includes:

Adding the oxalic acid solution to the electrolytic cell, under ice bath conditions, and applying a first preset voltage to the electrodes of the electrolytic cell, so that the preset substrate is oxidized in the electrolytic cell for a second preset time;

Setting the preset substrate in the film removal solution for a third preset time to remove the oxide film on the surface of the preset substrate;

Setting the preset substrate in the electrolytic tank, under ice bath conditions, and applying a second preset voltage to the electrodes of the electrolytic tank, so that the preset substrate is oxidized in the electrolytic tank for a fourth preset time;

The preset substrate is set in the pore-enlarging solution, and reacted at a preset temperature for a fifth preset time.

Optionally, the step of using the preset substrate to pick up the gold-silver alloy nanoparticle film and drying for the first preset time to obtain the gold-silver alloy annular nanostructure substrate specifically includes:

Cut the preset substrate for the second time;

obliquely inserting the predetermined substrate under the gold-silver alloy nanoparticle film in the container;

Lifting the preset substrate so that the gold-silver alloy nanoparticle film is attached to the surface of the preset substrate;

The preset substrate is left to stand for a first preset time so as to dry on the surface of the preset substrate.

Optionally, the alloy ratio of gold and silver in the gold-silver alloy nanoparticle colloidal suspension is 5:1-3:1.

Optionally, the first preset time is 30 minutes-60 minutes, the second preset time is 2 hours-3 hours, the third preset time is 1 hour-2 hours, and the fourth preset time is 3 minutes- 5 minutes, the fifth preset time is 30 minutes-40 minutes, the first preset voltage and the second preset voltage are both 40V-60V.

Optionally, the preset detection molecule is any one of rhodamine, crystal violet, and thiram.

The beneficial effects of the present invention are:

The method for preparing a gold-silver alloy annular nanostructure substrate provided by the application includes: mixing the prefabricated gold-silver alloy nanoparticle colloidal suspension with cyclohexane and setting it in a container, because the gold-silver alloy nanoparticle colloidal suspension If it is not compatible with cyclohexane, then the cyclohexane and the gold-silver alloy nanoparticle colloidal suspension are stratified, and the cyclohexane is on top, that is, there are two layers between the cyclohexane and the gold-silver alloy nanoparticle colloid. Phase self-assembly; the ethanol solution is injected into the container, so that the gold-silver alloy nanoparticles are captured by the interface between the aqueous solution and cyclohexane to form a thin film of gold-silver alloy nanoparticles, and the cyclohexane is taken out of the container, due to the ethanol solution Soluble in water, the ethanol solution is added to the gold-silver alloy nanoparticle colloid, so that the contact angle of the interface between the gold-silver alloy nanoparticle and the aqueous solution and cyclohexane is close to 90 degrees, and then the gold-silver alloy nanoparticle is in the aqueous solution. and cyclohexane; use the preset substrate to pick up the gold-silver alloy nanoparticle film, and dry for the first preset time to obtain the gold-silver alloy ring-shaped nanostructure substrate, wherein the preset substrate The bottom surface is provided with a plurality of nanoholes; the preset detection molecules are arranged on the surface of the gold-silver alloy ring-shaped nanostructure substrate; when the substrate of the present application is under the action of excitation light, the gold-silver alloy ring-shaped nanostructure substrate The substrate has different scattering characteristics for different detection molecules. The gold-silver alloy ring nanostructure substrate can enhance the Raman spectrum by increasing the light radiation efficiency of the detection molecules, that is, by increasing the intensity of the scattering peak, and because The gold-silver alloy ring-shaped nanostructure substrate prepared by the present application has less consumption and high yield, so that the cost of the gold-silver alloy ring-shaped nanostructure substrate prepared by the present application is correspondingly lower.

Description of drawings

In order to illustrate the technical solutions of the embodiments of the present invention more clearly, the accompanying drawings used in the embodiments will be briefly introduced below. It should be understood that the following drawings only show some embodiments of the present invention, and thus It should be regarded as a limitation on the scope, and those skilled in the art can also obtain other related drawings based on these drawings without creative work.

Fig. 1 is a schematic flow diagram of a method for preparing a gold-silver alloy annular nanostructure substrate provided in an embodiment of the present application;

2 is a schematic flow diagram of another method for preparing a gold-silver alloy annular nanostructure substrate provided in the embodiment of the present application;

3 is a schematic flow diagram of another method for preparing a gold-silver alloy annular nanostructure substrate provided in the embodiment of the present application;

4 is a schematic flow diagram of another method for preparing a gold-silver alloy annular nanostructure substrate provided in the embodiment of the present application;

5 is a structural diagram of the prepared structure of another method for preparing a gold-silver alloy annular nanostructure substrate provided by an embodiment of the present invention;

6 is a Raman spectrum of different concentrations of thiram adsorbed on the structure prepared by another method for preparing a gold-silver alloy ring-shaped nanostructure substrate provided by an embodiment of the present invention.

Detailed ways

The technical solutions in this application will be clearly and completely described below in conjunction with the drawings in this application. Obviously, the described embodiments are only some of the embodiments of this application, not all of them. The components of the application generally described and illustrated in the figures herein may be arranged and designed in a variety of different configurations. Accordingly, the following detailed description of the embodiments of the application provided in the accompanying drawings is not intended to limit the scope of the claimed application, but merely represents selected embodiments of the application. Based on the embodiments of the present application, all other embodiments obtained by those skilled in the art without making creative efforts belong to the scope of protection of the present application.

It should be noted that like numerals and letters denote similar items in the following figures, therefore, once an item is defined in one figure, it does not require further definition and explanation in subsequent figures.

In order to make the implementation process of the present invention clearer, the following will be described in detail in conjunction with the accompanying drawings.

Figure 1 is a schematic flow diagram of a method for preparing a gold-silver alloy annular nanostructure substrate provided in the embodiment of the application; as shown in Figure 1, the application provides a method for preparing a gold-silver alloy annular nanostructure substrate , methods include:

S101. Mix the prefabricated colloidal suspension of gold-silver alloy nanoparticles with cyclohexane and set them in a container.

The size and specifications of the container are set according to actual needs. For the convenience of explanation, the container is used as a beaker for example. The colloidal suspension of gold-silver alloy nanoparticles is water, and the solute is gold-silver alloy nanoparticles. Optional Specifically, the alloy ratio of gold and silver in the gold-silver alloy nanoparticle colloidal suspension is 5:1-3:1, that is, the ratio of gold nanoparticles and silver nanoparticles in the gold-silver alloy nanoparticle can be 3:1 , can also be 5:1, and can also be any ratio between 3:1-5:1, which is not specifically limited here. Since the colloidal suspension of gold-silver alloy nanoparticles is not fused with the cyclohexane, then The gold-silver alloy nanoparticle colloidal suspension and the cyclohexane are arranged in a container, the gold-silver alloy nanoparticle colloidal suspension and the cyclohexane will produce stratification, and the cyclohexane is in the upper layer, and the gold The colloidal suspension of silver alloy nanoparticles is in the lower layer, and the cyclohexane in the upper layer is an oil interface, and the colloidal suspension of gold-silver alloy nanoparticles in the lower layer is a water interface, and the gold-silver alloy nanoparticles are suspended inside the water interface; It is noted that at this time, the gold-silver alloy nanoparticles will not form a single-layer nanoparticle film in the water interface, and direct observation cannot be performed.

S102. Inject the ethanol solution into the container, so that the gold-silver alloy nanoparticles are captured by the interface between the aqueous solution and the cyclohexane to form a gold-silver alloy nanoparticle film, and take the cyclohexane out of the container.

The ethanol solution is slowly poured into the beaker along the wall of the beaker, because ethanol has the characteristics of being soluble in aqueous solution and cyclohexane solution, the addition of ethanol will make the gold-silver alloy nanoparticles at the water-oil interface The contact angle is close to 90 degrees. According to the principle of minimum energy, the gold-silver alloy nanoparticles will gather at the minimum energy interface, that is, the contact angle of the gold-silver alloy nanoparticles at the interface between the aqueous solution and cyclohexane is close to 90 degrees. That is, the gold-silver alloy nanoparticles are separated out at the interface position between the aqueous solution and cyclohexane to form a gold-silver alloy nanoparticle film, and the cyclohexane on the gold-silver alloy nanoparticle film upper layer is extracted using an appliance, so that The gold-silver alloy nanoparticle film is exposed on the upper layer of the water interface. After the upper layer solution is completely absorbed, a single-layer gold-silver alloy nanoparticle film is obtained and presents a metallic color; it should be noted that the number of gold-silver alloy nanoparticles at the interface Determined by the concentration of the suspension and the alloy ratio, the gold-silver alloy ratio in this application must be limited to 5:1-3:1, and the concentration is not limited here.

S103, using the preset substrate to scoop up the gold-silver alloy nanoparticle film, and dry it for a first preset time to obtain a gold-silver alloy annular nanostructure substrate.

A plurality of nanoholes are set on the preset substrate, the preset substrate is inserted into the bottom of the gold-silver alloy nanoparticle film in the beaker, and then the preset substrate and the gold-silver alloy nanoparticle film are picked up , so that the gold-silver alloy nanoparticle film is attached to the surface of the preset substrate, and the preset substrate is dried for a first preset time, so that the gold-silver alloy nanoparticle film on the preset substrate is closely adhered to The surface of the preset substrate, since the surface of the preset substrate is provided with a plurality of nanoholes, the gold-silver alloy nanoparticle film forms a ring structure complementary to the hole at the hole position of the preset substrate, and the The preset substrate is transformed from colorless to colored structure, that is, a gold-silver alloy annular nanostructure substrate is formed. In practical applications, the first preset time is any time between 30 minutes and 60 minutes, which is not specifically limited here; the material of the preset substrate is generally metal, which is not specifically limited here, for the sake of clarity Note, here, the material of the predetermined substrate is aluminum for description, and the shape of the predetermined substrate made of metal aluminum is generally aluminum foil, which is not specifically limited here.

S104. Setting preset detection molecules on the surface of the gold-silver alloy annular nanostructure substrate.

Under the incident excitation light, the gold-silver alloy ring-shaped nanostructure substrate has different scattering spectra for different detection molecules, and the preset probe molecules are naturally adsorbed on the surface of the gold-silver alloy ring-shaped nanostructure substrate , that is, the surface layer of the gold-silver alloy annular nanostructure substrate on the surface of the predetermined substrate is provided with a structural layer formed by probe molecules. Optionally, the preset detection molecule is any one of rhodamine, crystal violet, and thiram. In practical applications, the enhancement of the Raman signal of the substrate is generally judged by the strength of the Raman spectrum of the substrate. As a result, the preset detection molecules are used to detect proteins, industrial dyes, and pesticide residues.

Figure 2 is a schematic flow diagram of another method for preparing a gold-silver alloy annular nanostructure substrate provided by the embodiment of the present application; as shown in Figure 2, optionally, the gold-silver alloy nanoparticle The film is picked up and dried for the first preset time, before the step of obtaining the gold-silver alloy annular nanostructure substrate also includes:

S201. Cutting the preset substrate according to the size of the electrolytic cell.

Since the subsequent operation needs to set the preset substrate in the electrolytic cell, the preset substrate is cut according to the size of the electrolytic cell, so that the preset substrate can be set in the electrolytic cell. In practical applications, The length and width of the predetermined substrate may be slightly smaller than the length and width of the electrolytic cell, that is, the cut size of the predetermined substrate is determined according to actual needs, and is not specifically limited here.

S202, cleaning the preset substrate with acetone solution, ethanol solution, and deionized water.

Put the cut preset substrate into a beaker filled with acetone solution and soak it for a period of time to remove oil and organic matter on the surface of the preset substrate. In practical applications, the amount of acetone can make the preset substrate It is enough to cover the bottom, and there is no specific limitation here. The soaking time of the acetone solution is determined according to the actual needs. Clean the oil and organic matter on the surface. After cleaning, use deionized water to clean the surface of the preset substrate, and place the cleaned preset substrate in an oven for drying. The amount of acetone solution, ethanol solution, and deionized water The selection is made according to actual needs, and no specific limitation is made here.

S203, placing the predetermined substrate on the anode of the electrolytic cell, injecting a polishing solution into the electrolytic cell, and polishing the predetermined substrate in an ice bath.

The predetermined substrate after cleaning is placed on the anode of the electrolytic cell, and the cathode of the electrolytic cell is provided with a metal whose metallicity is lower than that of the predetermined substrate in this application. Generally, metal platinum is used to place the metal on the electrolytic cell. Cathode, the interior of the electrolytic cell is injected with a polishing solution. In practical applications, the polishing solution is generally prepared by using one part of water, one part of perchloric acid and one part of alcohol. The amount of one part of water is 2.78ml. One serving of perchloric acid is 10ml, and one serving of alcohol is 64ml. The amount of the polishing solution depends on actual needs, and is not specifically limited here. When the material of the preset substrate is aluminum, the voltage of the electrolytic cell is 8V under ice bath conditions, and the polishing time is 8 minutes to 15 minutes. , the voltage of the electrolytic cell and the polishing time are determined according to the material of the preset substrate, which is not specifically limited here, as long as the surface of the preset substrate is cleaned and polished.

Figure 3 is a schematic flow chart of another method for preparing a gold-silver alloy annular nanostructure substrate provided by the embodiment of the present application; as shown in Figure 3, optionally, the preset substrate is placed on the anode of the electrolytic cell , inject the polishing solution into the electrolytic cell, and after the step of polishing the preset substrate under ice bath conditions, it also includes:

S301. Add the oxalic acid solution into the electrolytic cell, and apply the first preset voltage to the electrodes of the electrolytic cell under ice bath conditions, so that the preset substrate is oxidized in the electrolytic cell for a second preset time.

The polished predetermined substrate is placed on the anode of the electrolytic cell, and the cathode of the electrolytic cell is provided with a metal whose metallicity is much smaller than that of the predetermined substrate in this application. Generally, metal platinum is used to place the metal on the electrolytic cell. Cathode, the electrolytic cell is injected with oxalic acid solution, which is generally prepared by using one part of 100ml of water and one part of 3.782g of oxalic acid. Specifically, under ice conditions, the preset substrate is oxidized for a second preset time at a preset oxidation voltage. It should be noted that both the oxidation time and the oxidation voltage will affect the morphology of the preset substrate after the first oxidation. , in practical applications, the preset oxidation voltage and the second preset time are determined according to actual needs, and are not specifically limited here. The second preset time is any time between 2 hours and 3 hours, and are not here Be specific.

S302, setting the preset substrate in the film removal solution for a third preset time, and removing the oxide film on the surface of the preset substrate.

Place the preset substrate oxidized in step S301 in a beaker filled with a film removal solution, and place the beaker at a first preset temperature for a third preset time to remove the surface of the preset substrate after primary oxidation. The oxide is thus oxidized for the second time. The second oxidation will make the surface of the pre-oxidized substrate form a more regular porous structure. The preparation of the film removal solution generally uses a part of 98ml of water and a part of 1ml of concentrated Sulfuric acid and a portion of 2.64g of potassium dichromate are formulated. It should be noted that in practical applications, the first preset temperature is determined according to actual needs, and is not specifically limited here. The third preset time It is any time from 1 hour to 2 hours, and is not specifically limited here.

S303. Set the preset substrate in the electrolytic tank, and apply the second preset voltage to the electrodes of the electrolytic tank under ice bath conditions, so that the preset substrate is oxidized in the electrolytic tank for a fourth preset time.

Place the preset substrate after film removal on the anode of the electrolytic cell, and the cathode of the electrolytic cell is provided with a metal whose metallicity is lower than that of the preset substrate in this application. Cathode, the electrolytic cell is injected with oxalic acid solution. The preparation of the oxalic acid solution is generally prepared by using one part of 100ml of water and one part of 3.782g of oxalic acid. The amount of the preset oxalic acid solution is determined according to actual needs. Here Not specifically limited, under ice conditions, the predetermined substrate is subjected to secondary oxidation for a fourth predetermined time at a predetermined oxidation voltage. It should be noted that both oxidation time and oxidation voltage will affect the predetermined substrate after secondary oxidation. In practical applications, the preset oxidation voltage and the fourth preset time are determined according to actual needs, which are not specifically limited here, that is, the preset oxidation voltage can be controlled by controlling the oxidation time and oxidation voltage. For the purpose of setting the size and number of nanoholes on the substrate, the fourth preset time is 3 minutes to 5 minutes.

S304. Place the preset substrate in the pore-enlarging solution, and react at a preset temperature for a fifth preset time.

Place the preset substrate after secondary oxidation in a beaker filled with a pore-enlarging solution, place the beaker at a second preset temperature and keep it for a fifth preset time, so as to prevent the formation of the preset substrate surface after secondary oxidation. The pore expansion of the porous nanostructure will increase the pore diameter and reduce the pore depth of the porous nanostructure of the preset substrate. The preparation of the pore-enlarging solution is generally prepared by using a part of 49ml of water and a part of 1ml of phosphoric acid As a result, it should be noted that in practical applications, the second preset temperature is set according to actual needs, and the fifth preset time is any time between 30 minutes and 40 minutes, which is determined according to actual needs. This is not specifically limited.

Figure 4 is a schematic flow chart of another method for preparing a gold-silver alloy annular nanostructure substrate provided by the embodiment of the present application; as shown in Figure 4, optionally, the gold-silver alloy nanoparticle The film is picked up and dried for the first preset time to obtain the gold-silver alloy annular nanostructure substrate. The steps specifically include:

S401. Perform second trimming on the preset substrate.

Carry out the second trimming of the preset substrate after the hole expansion, and the second trimming is to facilitate the transfer of gold-silver alloy nanoparticles. In practical applications, the preset substrate is trimmed for the second time according to the size of the container , it should be noted that, in practical applications, the length and width of the second trimming of the preset substrate are generally slightly smaller than the length and width of the bottom surface of the container.

S402, obliquely inserting the predetermined substrate under the gold-silver alloy nanoparticle film in the container.

Insert the preset substrate after secondary cutting obliquely into the single-layer gold-silver alloy nano-film formed by liquid-liquid two-phase self-assembly until the preset substrate is located under the film. This layer of film is enriched with enough nanoparticles, which is beneficial to The nanoparticles are transferred on the surface of the predetermined substrate.

S403. Lift the preset substrate, so that the gold-silver alloy nano particle film is attached to the surface of the preset substrate.

Lifting the preset substrate from the level of the single-layer gold-silver alloy nanoparticle film needs to be kept stable and shaking is prohibited. At this time, the surface of the preset substrate includes gold-silver alloy nanoparticles and a part of the colloidal suspension of gold-silver alloy nanoparticles.

S404. Let the preset substrate stand still for a first preset time, so as to dry on the surface of the preset substrate.

To completely transfer the gold-silver alloy nanoparticles on the surface of the preset substrate, the preset substrate needs to be left for the first preset time until the gold-silver alloy nano-particle colloidal suspension is completely evaporated, that is, the gold-silver alloy nanoparticles are transferred A gold-silver alloy annular nanostructure substrate is formed on the surface of the preset substrate.

Optionally, FIG. 5 is a structural diagram of the prepared structure of another method for preparing a gold-silver alloy annular nanostructure substrate provided by an embodiment of the present invention; as shown in FIG. 5 , the gold-silver alloy nanoparticles are surrounded by Preset the surrounding nanoholes of the substrate, and form a ring-shaped nanostructure around the nanoholes. The nanopores on the surface of the preset substrate are completely attached to the gold-silver alloy nanoparticles, forming a large-area ring-shaped nanostructure, and the nanoparticles are separated from each other. The ring-shaped nanostructures around a single nanohole are separated by being close but not connected, and the nanoparticle is not connected at the connection between the nanohole and the nanohole, and separated from each other to separate the ring-shaped nanostructure corresponding to each hole. The method for preparing a gold-silver alloy annular nanostructure substrate of the present application only uses the above-mentioned steps to simply realize the preparation of a gold-silver alloy annular nanostructure substrate, and because the formation of the annular nanostructure is based on the gold-silver alloy The nanoparticles are completely adsorbed on the surface of the predetermined substrate, and the nanoparticles are separated from each other due to electrostatic repulsion. Compared with other preparation methods, the preparation method of the present application has high stability, low cost and high yield.

Optionally, Fig. 6 is the Raman spectrum of thiram adsorbed at different concentrations by the prepared structure of another method for preparing a gold-silver alloy annular nanostructure substrate provided by an embodiment of the present invention; as shown in Fig. 6 , even if the concentration of thiram solution is as low as 10 ^-7 M, the characteristic peak of thiram at 1386cm ^-1 can still be detected, which is far lower than the maximum residue limit of 7ppm in fruits stipulated by the US Environmental Protection Agency. This application provides A liquid-liquid two-phase self-assembly method and a nanoparticle transfer method to generate a gold-silver alloy annular nanostructure substrate preparation method has a good application prospect.

The above are only preferred embodiments of the present invention, and are not intended to limit the present invention. For those skilled in the art, the present invention may have various modifications and changes. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principles of the present invention shall be included within the protection scope of the present invention.

Claims (7)

1. a method for preparing gold-silver alloy annular nanostructure substrate, is characterized in that, described method comprises: Mixing the prefabricated gold-silver alloy nanoparticle colloidal suspension with cyclohexane and setting it in the container; The ethanol solution is injected into the container, so that the gold-silver alloy nanoparticles are captured by the interface between the aqueous solution and the cyclohexane to form a thin film of gold-silver alloy nanoparticles, and the cyclohexane is removed from the container take out; Use the preset substrate to pick up the gold-silver alloy nanoparticle film and dry it for the first preset time to obtain a gold-silver alloy annular nanostructure substrate, wherein the preset substrate is aluminum foil, and the The preset substrate surface is provided with a plurality of nano-holes; The preset detection molecules are arranged on the surface of the gold-silver alloy ring-shaped nanostructure substrate. 2. the method for preparing gold-silver alloy annular nanostructure substrate according to claim 1, is characterized in that, described use preset substrate to pick up described gold-silver alloy nanoparticle film, and carry out drying first Before the preset time, the step of obtaining the gold-silver alloy annular nanostructure substrate also includes: cutting the preset substrate according to the size of the electrolytic cell; Use acetone solution, ethanol solution, deionized water to clean the preset substrate; The predetermined substrate is placed on the anode of the electrolytic cell, a polishing solution is injected into the electrolytic cell, and the predetermined substrate is polished under the condition of an ice bath. 3. the method for preparing gold-silver alloy annular nanostructure substrate according to claim 2, is characterized in that, described preset substrate is placed on the anode of described electrolyzer, in described electrolyzer Injecting the polishing solution, after the step of polishing the preset substrate under ice bath conditions, it also includes: Adding the oxalic acid solution into the electrolytic cell, under ice bath conditions, and loading a first preset voltage on the electrodes of the electrolytic cell, so that the preset substrate is oxidized in the electrolytic cell by a second preset voltage set time; Setting the preset substrate in the film removal solution for a third preset time to remove the oxide film on the surface of the preset substrate; Setting the preset substrate in the electrolytic cell, under ice bath conditions, and loading a second preset voltage on the electrodes of the electrolytic cell, so that the preset substrate is in the electrolytic cell Oxidize the fourth preset time; The preset substrate is placed in the pore-enlarging solution, and reacted at a preset temperature for a fifth preset time. 4. the method for preparing gold-silver alloy annular nanostructure substrate according to claim 3 is characterized in that, described use preset substrate to pick up described gold-silver alloy nanoparticle film, and carry out drying first Preset time, the step of obtaining the gold-silver alloy annular nanostructure substrate specifically includes: performing a second trimming on the preset substrate; obliquely inserting the preset substrate under the gold-silver alloy nanoparticle film in the container; Lifting the preset substrate so that the gold-silver alloy nanoparticle film is attached to the surface of the preset substrate; The preset substrate is left to stand for a first preset time, so that the dryness is on the surface of the preset substrate. 5. the method for preparing gold-silver alloy annular nanostructure substrate according to claim 4, is characterized in that, the alloy ratio of gold and silver in the described gold-silver alloy nanoparticle colloidal suspension is 5:1-3 :1. 6. the method for preparing gold-silver alloy annular nanostructure substrate according to claim 5, is characterized in that, described first preset time is 30 minutes-60 minutes, and described second preset time is 2 hours -3 hours, the third preset time is 1 hour-2 hours, the fourth preset time is 3 minutes-5 minutes, the fifth preset time is 30 minutes-40 minutes, the first Both the preset voltage and the second preset voltage are 40V-60V. 7. The method for preparing a gold-silver alloy annular nanostructure substrate according to claim 6, wherein the preset detection molecule is any one of rhodamine, crystal violet, and thiram.