Graphene-sensitized medium-metal hybrid structure localized surface plasmon resonance biochemical sensor as well as preparation method and application thereof

Abstract

The invention discloses a graphene-sensitized medium-metal hybrid structure localized surface plasmon resonance biochemical sensor as well as a preparation method and application thereof. The sensor is composed of a substrate and a sensing structure arranged on the substrate, the sensing structure is a graphene-sensitized medium-metal hybrid structure prepared by mechanical graphene stripping, template transfer and electron beam coating technologies, and comprises a medium layer arranged on a substrate and a silver nanodisk array arranged on the medium layer, the graphene sensitization layer is prepared through a mechanical stripping method and is transferred between the dielectric layer and the silver nanodisk array through the two-dimensional material transfer platform, localized surface plasma resonance sensing is achieved, and then detection of the refractive index and biochemical molecule concentration parameters of a to-be-detected medium can be achieved. According to the invention, high-sensitivity and narrow-bandwidth localized surface plasma resonance sensing is realized, and further detection of other parameters such as refractive index of a to-be-detected medium, biochemical molecule concentration and the like can be realized.

Description

Technical Field

[0001] The present invention belongs to the technical field of localized surface plasmon resonance sensors, and in particular relates to a graphene-sensitized dielectric-metal hybrid structure localized surface plasmon resonance biochemical sensor, and a preparation method and application thereof. Background Art

[0002] In recent years, localized surface plasmon resonance sensors have attracted much attention in the field of biochemical sensing due to their advantages such as portability, rapid analysis, in-situ monitoring, strong anti-interference ability and easy integration. Therefore, many optical sensors based on localized surface plasmon resonance have emerged, most of which use traditional metal nanostructures. Although metal nanostructures have high bulk refractive index sensing sensitivity, their application in the field of biochemical sensing is limited due to the high loss and weak biochemical molecule adsorption of metals. Therefore, designing a localized surface plasmon resonance sensor with low loss and strong biochemical molecule adsorption characteristics has become a technical problem that researchers need to solve urgently. Summary of the invention

[0003] The technical problem solved by the present invention is to provide a graphene-sensitized dielectric-metal hybrid structure localized surface plasmon resonance biochemical sensor with a simple structure and reasonable design and a preparation method thereof. The sensor comprises a glass substrate, a dielectric layer, a graphene sensitization layer and a metal nanostructure layer stacked in sequence from bottom to top, wherein the glass substrate has a thickness of 0.5 to 1.0 mm; the dielectric layer is a zinc sulfide layer with a thickness of 120 nm; the metal nanostructure layer is a silver layer with a thickness of 80 nm. Graphene, as a special two-dimensional material, has a large specific surface area due to its ultra-thin structure, providing abundant active sites for intermolecular interactions. In addition, the good biocompatibility of graphene also makes it widely used in the field of biochemical sensing. Adding a low-loss dielectric material to the metal nanostructure can reduce the bandwidth of the sensor and improve the sensing performance.

[0004] The present invention adopts the following technical scheme to solve the above technical problems. A graphene-sensitized dielectric-metal hybrid structure localized surface plasmon resonance biochemical sensor is characterized in that: the sensor is composed of a substrate and a sensing structure arranged on the substrate. The sensing structure is a graphene-sensitized dielectric-metal hybrid structure prepared by mechanically exfoliating graphene, template transfer and electron beam coating technology. The sensing structure includes a dielectric layer arranged on the substrate and a silver nanodisk array arranged on the dielectric layer. The graphene sensitization layer is prepared by mechanical exfoliation and transferred between the dielectric layer and the silver nanodisk array through a two-dimensional material transfer platform, thereby realizing localized surface plasmon resonance sensing, and further realizing the detection of the refractive index of the medium to be measured and the concentration parameters of biochemical molecules.

[0005] It is further defined that the substrate is a glass substrate with a thickness of 0.5-1.0 mm, and the use of a glass substrate with good light transmittance to support the sensing structure enables transmission spectrum measurement.

[0006] It is further defined that the dielectric layer is a zinc sulfide layer with a thickness of 120 nm, and the zinc sulfide layer is deposited on the glass substrate by electron beam evaporation.

[0007] It is further defined that the thickness of the silver nanodisk array is 80 nm.

[0008] The method for preparing the graphene-sensitized dielectric-metal hybrid structure localized surface plasmon resonance biochemical sensor of the present invention is characterized by the following specific steps: Step S1: placing the glass substrate in an ultrasonic cleaning machine and cleaning it in ethanol, acetone and deionized water in sequence, blowing nitrogen gas to remove moisture from its surface, and finally placing it in a vacuum drying oven for drying; Step S2: placing the dried glass substrate into a vacuum electron beam coating apparatus, and depositing a zinc sulfide layer with a thickness of 120 nm on the glass substrate by electron beam evaporation, and setting the coating rate to 0.6 A / s; Step S3: preparing a few-layer graphene by mechanical exfoliation, and transferring the few-layer graphene to a glass substrate coated with a zinc sulfide layer by a two-dimensional material transfer platform; Step S4: placing the PMMA / AAO composite template in acetone to dissolve the PMMA, suspending the AAO template in the acetone, and then transferring the AAO template to a glass substrate coated with a zinc sulfide layer, and bonding the AAO template to the zinc sulfide layer by air-drying the acetone, and finally obtaining an AAO template with a pore size of 300 nm and a thickness of 500 nm; Step S5: placing the glass substrate bonded with the AAO template into a vacuum electron beam coating apparatus, depositing a silver film with a thickness of 80 nm on the AAO template by electron beam evaporation, and setting the coating rate to 0.5 A / s; Step S6: Use M470 tape to peel off the AAO template on the surface of the sensor chip to obtain a large-area silver nanodisk array with high order and stable structure on the surface.

[0009] It is further defined that the PMMA / AAO composite template is prepared by secondary anodization, and the specific preparation steps are: Step S1: placing the aluminum substrate in an ultrasonic cleaning machine and cleaning it in ethanol, acetone and deionized water in sequence, and then drying it in a nitrogen environment, and then using a mixture of perchloric acid and ethanol in a volume ratio of 4:1 as an electrochemical polishing liquid, and polishing the upper and lower surfaces of the aluminum substrate by electrochemical polishing, wherein the electrochemical polishing voltage is 20V and the electrochemical polishing temperature is 10°C; Step S2: The treated aluminum substrate is first anodized in a 1wt% phosphoric acid solution to form a porous aluminum oxide layer, namely, an AAO template, on the surface of the aluminum substrate, wherein the anodizing voltage is 195V, the anodizing temperature is 4°C, and the anodizing time is 6h. The irregular anodized layer on the surface of the anodized aluminum substrate is chemically removed at 70°C for 9h using a mixture of 6wt% phosphoric acid and chromic acid. The aluminum substrate after chemical removal is then anodized for a second time in a 1wt% phosphoric acid solution to form a porous aluminum oxide layer, namely, an AAO template, on the surface of the aluminum substrate. The anodizing voltage is 195V, the anodizing temperature is 4°C, and the thickness of the AAO template is controlled to be 200nm by adjusting the second anodizing time. Step S3: Use PMMA or toluene solution to spin-coat the organic glass layer on the AAO template, then use a mixture of copper sulfate and hydrochloric acid to remove the aluminum substrate, and use a 5wt% phosphoric acid solution to remove the remaining thin barrier layer for 30 minutes. The pore size of the AAO template is controlled by the corrosion time of the phosphoric acid solution, and finally a PMMA / AAO template with a pore size of 300nm and a thickness of 500nm is obtained.

[0010] The application of the graphene-sensitized dielectric-metal hybrid structure localized surface plasmon resonance sensor in biochemical molecular recognition detection is characterized by the specific process of: using a halogen light source to emit wide-band light, exciting localized surface plasmon resonance by vertical incidence on the surface of a silver nanodisk array, and the incident light is compensated by the wave vector of the silver nanodisk array to further excite the surface plasmon resonance of the zinc sulfide layer, and finally collecting the transmitted light through one end of the optical fiber under the sensing structure, connecting the other end to a spectrometer for spectrum collection, and connecting the spectrometer to a computer to obtain real-time spectrum data, thereby realizing dual-channel sensing of localized surface plasmon resonance. Sensor, the signals of the two channels can refer to each other to enhance the stability of the sensor. The graphene sensitization layer attached to the surface of the zinc sulfide layer not only enhances the local characteristics of the high electric field formed by the local surface plasma resonance, but also improves the sensitivity of the sensor to the refractive index changes of the external environment. At the same time, due to the strong biochemical molecule adsorption characteristics of the graphene sensitization layer, it can amplify the sensing signals of biochemical molecules and reduce the detection limit of biochemical molecules. The medium-metal hybrid structure of the graphene sensitization reduces the bandwidth of the spectrum to 50nm, which is one-fourth of the bandwidth of the pure metal structure. The main measurement parameters of the two channels of the sensor are the refractive index to be measured and the concentration of biochemical molecules.

[0011] Compared with the prior art, the present invention has the following beneficial effects: the present invention adopts a bottom-up preparation method, and prepares a graphene-sensitized medium-metal hybrid structure through mechanical graphene exfoliation, template transfer, electron beam coating and other technologies, thereby realizing high-sensitivity and narrow-bandwidth localized surface plasmon resonance sensing, and further realizing the detection of other parameters such as the refractive index of the medium to be measured and the concentration of biochemical molecules; since the zinc sulfide layer and the nano silver disk array can be set to different geometric parameters to correspond to different resonance positions, the working band and sensitivity of the localized surface plasmon resonance sensor can be adjusted according to actual needs; in addition, due to the mode coupling of the zinc sulfide layer and the nano silver disk array, the sensing structure of the present invention can realize dual-channel sensing, so the stability of the sensor can be enhanced by mutual reference of the two channels during measurement. BRIEF DESCRIPTION OF THE DRAWINGS

[0012] Figure 1 is a schematic diagram of the structure of a localized surface plasmon resonance sensor; Figure 2 It is a flow chart of the preparation of localized surface plasmon resonance sensor; Figure 3 is the response spectrum of the localized surface plasmon resonance sensor when performing refractive index detection; Figure 4 It is a point-line relationship diagram between the resonance wavelength and the external refractive index; Figure 5 Schematic diagram of the layer-by-layer assembly for LSPR sensor surface sensitivity measurement; Figure 6 This is the response spectrum of the LSPR sensor when measuring surface sensitivity.

[0013] In the figure: 1-glass substrate with a thickness of 0.5~1.0mm, 2-zinc sulfide with a thickness of 120nm, 3-graphene sensitization layer, 4-silver nanodisk array with a thickness of 80nm. DETAILED DESCRIPTION

[0014] The above contents of the present invention are further described in detail below through examples, but this should not be understood as the scope of the above subject matter of the present invention being limited to the following examples, and all technologies implemented based on the above contents of the present invention belong to the scope of the present invention. Example

[0015] like Figure 1As shown, a graphene-sensitized dielectric-metal hybrid structure localized surface plasmon resonance sensor is composed of a glass substrate and a sensing structure arranged on the glass substrate. The sensing structure adopts a bottom-up preparation method, and the graphene-sensitized dielectric-metal hybrid structure is prepared by mechanical peeling of graphene, template transfer and electron beam coating techniques. The glass substrate is a glass substrate 1 with a thickness of 0.5-1.0 mm, on which are sequentially a zinc sulfide layer 2 with a thickness of 120 nm and a silver nanodisk array 4 with a thickness of 80 nm. The graphene sensitization layer 3 is prepared by mechanical peeling and transferred between the zinc sulfide layer and the silver nanodisk array through a two-dimensional material transfer platform; the silver nanodisk array is prepared by AAO template transfer combined with electron beam evaporation deposition.

[0016] The invention utilizes a halogen light source to emit a wide-band light, and excites the localized surface plasma resonance by vertically incident on the surface of a silver nanodisk array, and the incident light can further excite the surface plasma resonance of a zinc sulfide layer after wave vector compensation of the silver nanodisk array; finally, the transmitted light is collected through one end of an optical fiber below the sensing structure, and the other end is connected to a spectrometer for spectrum acquisition, and the spectrometer is connected to a computer to obtain real-time spectrum data, thereby realizing a localized surface plasma resonance sensor with dual-channel sensing; the graphene sensitization layer attached to the surface of the zinc sulfide layer not only strengthens the localized characteristics of the high-intensity electric field formed by the localized surface plasma resonance, and improves the sensitivity of the sensor to the refractive index change of the external environment, but also can amplify the sensing signal of the biochemical molecule and reduce the detection limit of the biochemical molecule due to the strong biochemical molecule adsorption characteristics of the graphene sensitization layer; and the medium-metal hybrid structure sensitized by the graphene reduces the bandwidth of the spectrum to 50nm, which is one-fourth of the bandwidth of the pure metal structure, thereby improving the overall sensing performance of the sensor.

[0017] The PMMA / AAO composite template of the present invention is synthesized by secondary anodization treatment, and the specific preparation steps are as follows: Step S1: taking a 2cm*2cm aluminum substrate and placing it in an ultrasonic cleaning machine, cleaning it in ethanol, acetone and deionized water for 5 minutes in sequence, and then drying it in a nitrogen environment, and then using a mixture of perchloric acid and ethanol in a volume ratio of 4:1 as an electrochemical polishing liquid, and polishing the upper and lower surfaces of the aluminum substrate by electrochemical polishing, wherein the electrochemical polishing voltage is 20V, and the electrochemical polishing temperature is 10°C; Step S2: The treated aluminum substrate is first anodized in a 1wt% phosphoric acid solution to form a porous aluminum oxide layer, namely, an AAO template, on the surface of the substrate, wherein the anodizing voltage is 195V, the anodizing temperature is 4°C, and the anodizing time is 6h. The irregular anodized layer on the surface of the anodized aluminum substrate is chemically removed at 70°C for 9h using a mixture of 6wt% phosphoric acid and chromic acid. The aluminum substrate after chemical removal is then anodized for a second time in a 1wt% phosphoric acid solution to form a porous aluminum oxide layer, namely, an AAO template, on the surface of the aluminum substrate. The anodizing voltage is 195V, the anodizing temperature is 4°C, and the thickness of the AAO template is controlled to be 200nm by adjusting the second anodizing time. Step S3: Use PMMA or toluene solution to spin-coat the organic glass layer on the AAO template, then use a mixture of copper sulfate and hydrochloric acid to remove the aluminum substrate, and use a 5wt% phosphoric acid solution to remove the remaining thin barrier layer for 30 minutes. The pore size of the AAO template is controlled by the corrosion time of the phosphoric acid solution, and finally a PMMA / AAO template with a pore size of 300nm and a thickness of 500nm is obtained.

[0018] The method for preparing the graphene-sensitized dielectric-metal hybrid structure localized surface plasmon resonance sensor of the present invention comprises the following specific preparation steps: Step S1: Take a 2 cm * 2 cm glass substrate and place it in an ultrasonic cleaner to clean it in ethanol, acetone and deionized water for 5 min in sequence, blow nitrogen to remove the moisture on its surface, and finally place it in a vacuum drying oven to dry; Step S2: placing the dried glass substrate into a vacuum electron beam coating apparatus, and depositing a zinc sulfide layer with a thickness of 120 nm on the glass substrate by electron beam evaporation, and setting the coating rate to 0.6 A / s; Step S3: preparing a few-layer graphene by mechanical exfoliation, and transferring the few-layer graphene to a glass substrate coated with a zinc sulfide layer by a two-dimensional material transfer platform; Step S4: placing the PMMA / AAO composite template in acetone to dissolve the PMMA, suspending the AAO template in the acetone, and then transferring the AAO template to a glass substrate coated with a zinc sulfide layer, and bonding the AAO template to the zinc sulfide layer by air-drying the acetone, and finally obtaining an AAO template with a pore size of 300 nm and a thickness of 500 nm; Step S5: placing the glass substrate bonded with the AAO template into a vacuum electron beam coating apparatus, depositing a silver film with a thickness of 80 nm on the AAO template by electron beam evaporation, and setting the coating rate to 0.5 A / s; Step S6: Use M470 tape to peel off the AAO template on the surface of the sensor chip to obtain a large-area silver nanodisk array with high order and stable structure on the surface.

[0019] The application of the graphene-sensitized medium-metal hybrid structure localized surface plasmon resonance sensor in the specific detection of biochemical molecules of the present invention is as follows: a halogen light source is used to emit a wide-band light, and the localized surface plasmon resonance is excited by vertical incidence on the surface of the silver nanodisk array, and the incident light is compensated by the wave vector of the silver nanodisk array, which can further excite the surface plasmon resonance of the zinc sulfide layer; finally, the transmitted light is collected by one end of the optical fiber below the sensing structure, and the other end is connected to the spectrometer for spectrum collection, and the spectrometer is connected to the computer to obtain real-time spectrum data, so as to realize the localized surface plasmon resonance sensor with dual-channel sensing; the graphene sensitization layer attached to the surface of the zinc sulfide layer not only strengthens the local characteristics of the high-intensity electric field formed by the localized surface plasmon resonance, but also improves the sensitivity of the sensor to the refractive index change of the external environment. At the same time, due to the strong biochemical molecule adsorption characteristics of the graphene sensitization layer, the sensing signal of the biochemical molecule can be amplified, and the detection limit of the biochemical molecule can be reduced. The graphene-sensitized medium-metal hybrid structure reduces the bandwidth of the spectrum to 50nm, which is one-fourth of the bandwidth of the pure metal structure, improving the overall sensing performance of the sensor. By adjusting the geometric parameters of the zinc sulfide layer and the nanosilver disk array, different resonance wavelength positions can be excited, and then the working band of the localized surface plasmon resonance sensor can be tuned to the near-infrared band, greatly improving the measurement sensitivity of the sensor. Both sensing channels can measure the refractive index of the medium to be measured and the concentration of biochemical molecules. In addition, the dual sensing channels can refer to each other in actual measurements to enhance the stability of the sensor.

[0020] Figure 3 This is the response spectrum of the localized surface plasmon resonance sensor when performing refractive index detection. It can be seen from the figure that as the external refractive index increases from 1.33 to 1.37, the resonance wavelengths of the two channels tend to redshift to higher bands.

[0021] Figure 4 The figure is a point-line relationship diagram between the signal resonance wavelength and the external refractive index. It can be seen from the figure that with the increase of the external refractive index, the spectra of channel 1 and channel 2 change to varying degrees, among which the change degree of channel 2 is more obvious, and the resonance wavelength red-shifts from 714nm to 725nm. The refractive index sensitivity of the LSPR sensor is also higher, calculated as S1=281nm / RIU, while the resonance wavelength of channel 2 red-shifts from 639nm to 642nm, calculated as S2=80.75nm / RIU. Based on the smaller refractive index sensitivity of channel 1, it can be used as a reference signal to increase the stability of the sensor.

[0022] Figure 5Schematic diagram of the layer-by-layer assembly for the surface sensitivity measurement of the LSPR sensor. The molecular layer deposition method was used to probe the surface sensitivity of the sensor. The positively charged polymer (allylamine hydrochloride) (PAH, 65 kDa) and the negatively charged polymer (styrene sulfonate) (PSS, 75 kDa) were assembled layer by layer on the surface of the proposed LSPR sensing structure. The thickness of the polyelectrolyte bilayer measured by ellipsometry was about 2.9 nm and the refractive index was 1.56.

[0023] Figure 6 This is the response spectrum of the LSPR sensor during surface sensitivity measurement. The results show that with the continuous deposition of molecular layers, the spectral shift gradually decreases, which indicates that the surface sensitivity is decreasing. The calculated attenuation length of the surface sensitivity is 72nm, which is higher than the LSPR sensor with traditional metal structure. This is because the higher specific surface area of ​​graphene makes the sensor have a stronger adsorption effect on biochemical small molecules, thereby increasing the sensitivity of biochemical molecule detection.

[0024] The above embodiments describe the basic principles, main features and advantages of the present invention. Those skilled in the art should understand that the present invention is not limited to the above embodiments. The above embodiments and descriptions are only for illustrating the principles of the present invention. Without departing from the scope of the principles of the present invention, the present invention may have various changes and improvements, and these changes and improvements all fall within the scope of protection of the present invention.

Claims

1. A graphene-sensitized dielectric-metal hybrid structure localized surface plasmon resonance biochemical sensor, characterized in that: The sensor is composed of a substrate and a sensing structure arranged on the substrate. The sensing structure is a graphene-sensitized medium-metal hybrid structure prepared by mechanically exfoliating graphene, template transfer and electron beam coating technology. The sensing structure includes a medium layer arranged on the substrate and a silver nanodisk array arranged on the medium layer. The graphene sensitization layer is prepared by mechanical exfoliation and transferred between the medium layer and the silver nanodisk array through a two-dimensional material transfer platform, thereby realizing localized surface plasma resonance sensing, and further being able to realize the detection of the refractive index of the medium to be measured and the concentration parameters of biochemical molecules.

2. The graphene-sensitized dielectric-metal hybrid structure localized surface plasmon resonance biochemical sensor according to claim 1, characterized in that: The substrate is a glass substrate with a thickness of 0.5-1.0 mm. The glass substrate with good light transmittance is used to support the sensing structure so as to perform transmission spectrum measurement.

3. The graphene-sensitized dielectric-metal hybrid structure localized surface plasmon resonance biochemical sensor according to claim 1, characterized in that: The dielectric layer is a zinc sulfide layer with a thickness of 120 nm, and the zinc sulfide layer is deposited on a glass substrate by electron beam evaporation.

4. The graphene-sensitized dielectric-metal hybrid structure localized surface plasmon resonance biochemical sensor according to claim 1, characterized in that: The thickness of the silver nanodisk array is 80 nm.

5. A method for preparing a graphene-sensitized dielectric-metal hybrid structure localized surface plasmon resonance biochemical sensor according to any one of claims 1 to 4, characterized in that The specific steps are: Step S1: placing the glass substrate in an ultrasonic cleaning machine and cleaning it in ethanol, acetone and deionized water in sequence, blowing nitrogen gas to remove moisture from its surface, and finally placing it in a vacuum drying oven for drying; Step S2: placing the dried glass substrate into a vacuum electron beam coating apparatus, depositing a zinc sulfide layer with a thickness of 120 nm on the glass substrate by electron beam evaporation, and setting the coating rate to 0.6 A / s; Step S3: preparing a few-layer graphene by a mechanical exfoliation method, and transferring the few-layer graphene to a glass substrate coated with a zinc sulfide layer by a two-dimensional material transfer platform; Step S4: placing the PMMA / AAO composite template in acetone to dissolve the PMMA, suspending the AAO template in the acetone, and then transferring the AAO template to a glass substrate coated with a zinc sulfide layer, and bonding the AAO template to the zinc sulfide layer by air-drying the acetone, and finally obtaining an AAO template with a pore size of 300 nm and a thickness of 500 nm; Step S5: placing the glass substrate bonded with the AAO template into a vacuum electron beam coating apparatus, depositing a silver film with a thickness of 80 nm on the AAO template by electron beam evaporation, and setting the coating rate to 0.5 A / s; Step S6: Use M470 tape to peel off the AAO template on the surface of the sensor chip to obtain a large-area silver nanodisk array with high order and stable structure on the surface.

6. The method for preparing the graphene-sensitized dielectric-metal hybrid structure localized surface plasmon resonance biochemical sensor according to claim 4, characterized in that: The PMMA / AAO composite template is prepared by secondary anodization, and the specific preparation steps are as follows: Step S1: placing the aluminum substrate in an ultrasonic cleaning machine and cleaning it in ethanol, acetone and deionized water in sequence, and then drying it in a nitrogen environment, and then using a mixture of perchloric acid and ethanol in a volume ratio of 4:1 as an electrochemical polishing liquid, and polishing the upper and lower surfaces of the aluminum substrate by electrochemical polishing, wherein the electrochemical polishing voltage is 20V and the electrochemical polishing temperature is 10°C; Step S2: The treated aluminum substrate is first anodized in a 1wt% phosphoric acid solution to form a porous aluminum oxide layer, namely, an AAO template, on the surface of the aluminum substrate, wherein the anodizing voltage is 195V, the anodizing temperature is 4°C, and the anodizing time is 6h. The irregular anodized layer on the surface of the anodized aluminum substrate is chemically removed at 70°C for 9h using a mixture of 6wt% phosphoric acid and chromic acid. The aluminum substrate after chemical removal is then anodized for a second time in a 1wt% phosphoric acid solution to form a porous aluminum oxide layer, namely, an AAO template, on the surface of the aluminum substrate. The anodizing voltage is 195V, the anodizing temperature is 4°C, and the thickness of the AAO template is controlled to be 200nm by adjusting the second anodizing time. Step S3: Use PMMA or toluene solution to spin-coat the organic glass layer on the AAO template, then use a mixture of copper sulfate and hydrochloric acid to remove the aluminum substrate, and use a 5wt% phosphoric acid solution to remove the remaining thin barrier layer for 30 minutes. The pore size of the AAO template is controlled by the corrosion time of the phosphoric acid solution, and finally a PMMA / AAO template with a pore size of 300nm and a thickness of 500nm is obtained.

7. Application of the graphene-sensitized dielectric-metal hybrid structure localized surface plasmon resonance biochemical sensor according to any one of claims 1 to 4 in biochemical molecule recognition detection.

8. The use according to claim 6, characterized in that The specific process is as follows: a halogen light source is used to emit a wide-band light, which is vertically incident on the surface of the silver nanodisk array to excite the localized surface plasmon resonance. The incident light is compensated by the wave vector of the silver nanodisk array to further excite the surface plasmon resonance of the zinc sulfide layer. Finally, the transmitted light is collected through one end of the optical fiber below the sensing structure, and the other end is connected to a spectrometer for spectrum acquisition. The spectrometer is connected to a computer to obtain real-time spectrum data, thereby realizing a dual-channel sensing localized surface plasmon resonance sensor. The signals of the two channels can refer to each other to enhance the stability of the sensor. The graphene sensitization layer attached to the surface of the zinc sulfide layer not only enhances the local characteristics of the high electric field formed by the localized surface plasmon resonance, but also enhances the sensitivity of the sensor to changes in the refractive index of the external environment. At the same time, due to the strong biochemical molecule adsorption characteristics of the graphene sensitization layer, the sensing signal of the biochemical molecule can be amplified, and the detection limit of the biochemical molecule can be reduced. The medium-metal hybrid structure of the graphene sensitization reduces the bandwidth of the spectrum to 50nm, which is one-fourth of the bandwidth of the pure metal structure. The main measurement parameters of the two channels of the sensor are the refractive index to be measured and the concentration of biochemical molecules.

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