Three-dimensional SERS substrate based on ReS2 and its preparation method and application

Abstract

The present invention discloses a three-dimensional SERS substrate based on ReS2 and its preparation method and application, wherein the SERS substrate comprises a substrate, and the surface of the substrate is coated with Au, ReS2 and Ag thin films in sequence. The presence of the Au film can effectively help the rhenium disulfide nanosheets to be adsorbed on the substrate to form a three-dimensional nanocavity, providing sufficient adsorption area for Ag and the object to be detected, thereby significantly improving the sensitivity of SERS.

Description

Technical Field

[0001] The present invention belongs to the field of Raman detection technology, and in particular relates to a three-dimensional SERS substrate based on ReS2 and a preparation method and application thereof. Background Art

[0002] The statements in this section merely provide background information related to the present disclosure and do not necessarily constitute prior art.

[0003] Surface enhanced Raman spectroscopy (SERS) is a non-destructive, ultra-sensitive analytical technique that can accurately and sensitively identify substances through the characteristic vibration peaks of special groups in substances. In long-term SERS research, it was found that noble metals (Au, Ag, Cu) can exhibit a strong SERS effect, making them a hot topic in SERS substrate research. However, the function of noble metal SERS substrates is single, and their development is greatly restricted.

[0004] Studies have proven that composite materials composed of two-dimensional materials and precious metals have better detection capabilities and more diverse functions than single two-dimensional materials and precious metals. Existing composite materials composed of two-dimensional materials and precious metals are commonly found in the combination of molybdenum disulfide with gold and silver. However, the above schemes have the following problems: the preparation process mostly requires growth, centrifugation, transfer and other steps, and the experiment is cumbersome; the transfer coating process will lead to poor uniformity of the substrate, which is difficult to meet the actual detection needs; the interaction between the composite material and the substrate is weak, easy to fall off, and poor stability. Summary of the invention

[0005] In order to overcome the above-mentioned deficiencies of the prior art, the present invention provides a three-dimensional SERS substrate based on ReS2 and its preparation method and application. The presence of the Au film can effectively help the rhenium disulfide nanosheets to be adsorbed on the substrate to form a three-dimensional nanocavity, providing sufficient adsorption area for Ag and the object to be detected, thereby significantly improving the sensitivity of SERS.

[0006] To achieve the above objectives, one or more embodiments of the present invention provide the following technical solutions:

[0007] A three-dimensional SERS substrate based on ReS2 comprises a substrate, the surface of which is sequentially coated with Au, ReS2 and Ag films.

[0008] Further, the following steps are included:

[0009] A layer of Au thin film is evaporated on the substrate;

[0010] ammonium perrhenate, hydroxylamine hydrochloride and L-cysteine ​​are mixed in deionized water to obtain a precursor solution;

[0011] The substrate with the Au thin film evaporated thereon and the precursor solution are heated to obtain a substrate coated with Au / ReS2 composite nanosheets;

[0012] A layer of Ag film is evaporated on a substrate coated with Au / ReS2 composite nanosheets to obtain a SERS substrate with an Au / ReS2 / Ag composite structure.

[0013] Furthermore, before evaporating a layer of Au film on the substrate, the substrate is cleaned.

[0014] Furthermore, the evaporation coating method adopts vacuum evaporation coating method, magnetron sputtering coating method or ion plating method.

[0015] Furthermore, the Au film is 7nm.

[0016] Furthermore, the concentrations of the ammonium perrhenate, hydroxylamine hydrochloride and L-cysteine ​​are all 0.1 M, the volumes are 0.4-1 ml, 3 ml and 3 ml respectively, and the volume of the deionized water is 3 ml.

[0017] Furthermore, the substrate with the Au thin film evaporated thereon and the precursor solution are heated in a 25-500 ml hydrothermal reactor. After the temperature reaches 200° C., the temperature is kept constant for 2-6 hours and then slowly cooled to room temperature.

[0018] Furthermore, the Ag film is 15 nm.

[0019] One or more embodiments provide a SERS sensor, comprising the SERS substrate.

[0020] One or more embodiments provide a SERS sensor system, including the SERS sensor.

[0021] One or more of the above technical solutions have the following beneficial effects:

[0022] The above technical solution provides an Au / ReS2 / Ag three-dimensional composite material substrate, in which the presence of the Au film can effectively help the rhenium disulfide nanosheets to be adsorbed on the substrate to form a three-dimensional nanocavity, providing sufficient adsorption area for Ag and the object to be detected, thereby significantly improving the sensitivity of SERS;

[0023] Large-area, high-quality ReS2 nanosheets composited with Ag nanoparticles effectively extend the lifetime of hot electrons.

[0024] The property of ReS2 nanosheets to deform due to changes in ambient temperature can realize hotspot regulation of SERS substrate.

[0025] During the preparation, just put the Au-modified pyramid silicon wafer into the hydrothermal reactor. After heating, plate a layer of Ag on the surface of the substrate to obtain a large-area, high-quality Au / ReS2 / Ag composite material. Compared with the existing preparation method, it has the advantages of low cost, simple operation steps, good repeatability and easy mass production, and the obtained substrate has high sensitivity and good uniformity. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] The accompanying drawings in the specification, which constitute a part of the present invention, are used to provide a further understanding of the present invention. The exemplary embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute improper limitations on the present invention.

[0027] Figure 1 A scanning electron microscope image of the novel Au / ReS2 / Ag thin film SERS substrate provided by the present invention;

[0028] Figure 2 A Raman spectrum of a novel SERS substrate of Au / ReS2 / Ag thin film prepared according to an embodiment of the present invention;

[0029] Figure 3 The Raman enhancement effect of the Au / ReS2 / Ag thin film novel SERS substrate prepared according to the embodiment of the present invention on the Rhodamine 6G molecule is compared with the substrate;

[0030] Figure 4 This is a temperature response Raman spectrum of the novel SERS substrate of Au / ReS2 / Ag thin film prepared according to an embodiment of the present invention. DETAILED DESCRIPTION

[0031] It should be noted that the following detailed descriptions are exemplary and are intended to provide further explanation of the present invention. Unless otherwise specified, all technical and scientific terms used herein have the same meanings as those commonly understood by those skilled in the art to which the present invention belongs.

[0032] It should be noted that the terms used herein are only for describing specific embodiments and are not intended to limit exemplary embodiments according to the present invention. As used herein, unless the context clearly indicates otherwise, the singular form is also intended to include the plural form. In addition, it should be understood that when the terms "comprising" and / or "including" are used in this specification, it indicates the presence of features, steps, operations, devices, components and / or combinations thereof.

[0033] In the absence of conflict, the embodiments of the present invention and the features of the embodiments may be combined with each other.

[0034] Rhenium disulfide (ReS2) is a new type of transition metal dihalide material with stable chemical properties, large surface area, high carrier mobility, and has been proven to have a significant Raman enhancement effect in ReS2 films. However, current research has not fully applied ReS2 to Raman detection to explore its development potential in this field.

[0035] One or more embodiments of the present invention provide a three-dimensional SERS substrate based on ReS2, including a substrate, the surface of which is coated with gold, rhenium disulfide and silver films in sequence. The characteristic of ReS2 nanosheets that deform when the ambient temperature changes can realize the hot spot regulation of the SERS substrate. Ag nanoparticles adsorbed on ReS2 nanosheets can significantly improve the sensitivity of SERS.

[0036] The method for preparing the three-dimensional SERS substrate comprises the following steps:

[0037] A layer of Au thin film is evaporated on the substrate;

[0038] ammonium perrhenate, hydroxylamine hydrochloride and L-cysteine ​​are mixed in deionized water to obtain a precursor solution;

[0039] The substrate with the Au thin film evaporated thereon and the precursor solution are heated to obtain a substrate coated with Au / ReS2 composite nanosheets;

[0040] A layer of Ag film is evaporated on a substrate coated with Au / ReS2 composite nanosheets to obtain a SERS substrate with an Au / ReS2 / Ag composite structure.

[0041] The evaporation may be performed by vacuum evaporation coating, magnetron sputtering coating or ion plating.

[0042] Example 1

[0043] This embodiment provides a method for preparing a three-dimensional SERS substrate based on ReS2, which specifically includes the following steps:

[0044] (1) Cleaning of substrate:

[0045] A substrate made of single crystal silicon material is first placed in acetone and ultrasonically cleaned in an ultrasonic machine for fifteen minutes; then the substrate is placed in ethanol and ultrasonically cleaned in an ultrasonic machine for fifteen minutes; finally, the substrate is further placed in deionized water and ultrasonically cleaned in an ultrasonic machine for fifteen minutes to obtain a clean substrate. The substrate is made of pyramid silicon.

[0046] (2) Preparation of gold film:

[0047] The clean substrate obtained by cleaning in step (1) is placed in a vacuum evaporation coating device. A gold rake with a purity of 99.99% is used as the evaporation source. After evacuating to 8×10-6 Torr, the current rate is controlled for evaporation to deposit a layer of Au film with a thickness of about 7 nm on the clean and flat substrate.

[0048] (3) Precursor fluid preparation:

[0049] Use a 1 / 10,000 balance to weigh a certain mass of ammonium perrhenate, hydroxylamine hydrochloride and L-cysteine ​​powder and put them into a container. Use a pipette to take deionized water and inject it into the container containing the mixed powder to prepare a precursor solution. Then put the precursor solution into an ultrasonic machine for ultrasonic treatment for 20 minutes to crush the mixed powder and form a uniform solution. Specifically, the concentration of ammonium perrhenate, hydroxylamine hydrochloride and L-cysteine ​​is 0.1M, the volume is 0.4-1ml, 3ml and 3ml respectively, and the volume of deionized water is 3ml.

[0050] (4) Transfer of precursor solution:

[0051] Use a pipette to transfer the precursor solution prepared in step 3 into a 25-500 ml hydrothermal reactor.

[0052] (5) Heat treatment to obtain Au / ReS2 substrate:

[0053] The hydrothermal reactor obtained in step (4) was placed in a thermostat and heated. After the temperature reached 200°C, the temperature was kept constant for 2 hours. Thereafter, the thermostat was slowly cooled to room temperature. The substrate was taken out from the hydrothermal reactor to obtain a 70nm Au / ReS2 substrate.

[0054] (6) Evaporation treatment to obtain a new type of SERS substrate of Au / ReS2 / Ag thin film:

[0055] The Au / ReS2 substrate obtained in step (5) is placed in a vacuum evaporation coating device. A silver rake with a purity of 99.99% is used as the evaporation source. After evacuating to 8×10-6 Torr, the current rate is controlled to evaporate and a layer of Ag with a thickness of about 15 nm is deposited on a clean and flat substrate to obtain a new SERS substrate of Au / ReS2 / Ag thin film.

[0056] Example 2

[0057] This embodiment provides a method for preparing a three-dimensional SERS substrate based on ReS2, which specifically includes the following steps:

[0058] (1) Cleaning of substrate:

[0059] A substrate made of single crystal silicon material is first placed in acetone and ultrasonically cleaned in an ultrasonic machine for fifteen minutes; then the substrate is placed in ethanol and ultrasonically cleaned in an ultrasonic machine for fifteen minutes; finally, the substrate is further placed in deionized water and ultrasonically cleaned in an ultrasonic machine for fifteen minutes to obtain a clean substrate. The substrate is made of pyramid silicon.

[0060] (2) Preparation of gold film:

[0061] The clean substrate obtained by cleaning in step (1) is placed in a vacuum evaporation coating device. A gold rake with a purity of 99.99% is used as the evaporation source. After evacuating to 8×10-6 Torr, the current rate is controlled for evaporation to deposit a layer of Au film with a thickness of about 7 nm on the clean and flat substrate.

[0062] (3) Precursor fluid preparation:

[0063] Use a 1 / 10,000 balance to weigh a certain mass of ammonium perrhenate, hydroxylamine hydrochloride and L-cysteine ​​powder and put them into a container. Use a pipette to take deionized water and inject it into the container containing the mixed powder to prepare a precursor solution. Then put the precursor solution into an ultrasonic machine for ultrasonic treatment for 20 minutes to crush the mixed powder and form a uniform solution. Specifically, the concentration of ammonium perrhenate, hydroxylamine hydrochloride and L-cysteine ​​is 0.1M, the volume is 0.4-1ml, 3ml and 3ml respectively, and the volume of deionized water is 3ml.

[0064] (4) Transfer of precursor solution:

[0065] Use a pipette to transfer the precursor solution prepared in step 3 into a 25-500 ml hydrothermal reactor.

[0066] (5) Heat treatment to obtain Au / ReS2 substrate:

[0067] The hydrothermal reactor obtained in step (4) was placed in a thermostat and heated. After the temperature reached 200°C, the temperature was kept constant for 6 hours. Thereafter, the thermostat was slowly cooled to room temperature. The substrate was taken out from the hydrothermal reactor to obtain a 70nm Au / ReS2 substrate.

[0068] (6) Evaporation treatment to obtain a new type of SERS substrate of Au / ReS2 / Ag thin film:

[0069] The Au / ReS2 substrate obtained in step (5) is placed in a vacuum evaporation coating device. A silver rake with a purity of 99.99% is used as the evaporation source. After evacuating to 8×10-6 Torr, the current rate is controlled to evaporate and a layer of Ag with a thickness of about 15 nm is deposited on a clean and flat substrate to obtain a new SERS substrate of Au / ReS2 / Ag thin film.

[0070] Example 3

[0071] This embodiment discloses a method for preparing a three-dimensional SERS substrate based on ReS2, which specifically includes the following steps:

[0072] (1) Cleaning of substrate:

[0073] A substrate made of single crystal silicon material is first placed in acetone and ultrasonically cleaned in an ultrasonic machine for fifteen minutes; then the substrate is placed in ethanol and ultrasonically cleaned in an ultrasonic machine for fifteen minutes; finally, the substrate is further placed in deionized water and ultrasonically cleaned in an ultrasonic machine for fifteen minutes to obtain a clean substrate. The substrate is made of pyramid silicon.

[0074] (2) Preparation of gold film:

[0075] The clean substrate obtained by cleaning in step (1) is placed in a magnetron sputtering coating device. A gold rake with a purity of 99.99% is used as the evaporation source. After evacuating to 8×10-6 Torr, the current rate is controlled to evaporate and a layer of Au film with a thickness of about 7 nm is deposited on the clean and flat substrate.

[0076] (3) Precursor fluid preparation:

[0077] Use a 1 / 10,000 balance to weigh a certain mass of ammonium perrhenate, hydroxylamine hydrochloride and L-cysteine ​​powder and put them into a container. Use a pipette to take deionized water and inject it into the container containing the mixed powder to prepare a precursor solution. Then put the precursor solution into an ultrasonic machine for ultrasonic treatment for 20 minutes to crush the mixed powder and form a uniform solution. Specifically, the concentration of ammonium perrhenate, hydroxylamine hydrochloride and L-cysteine ​​is 0.1M, the volume is 0.4-1ml, 3ml and 3ml respectively, and the volume of deionized water is 3ml.

[0078] (4) Transfer of precursor solution:

[0079] Use a pipette to transfer the precursor solution prepared in step 3 into a 25-500 ml hydrothermal reactor.

[0080] (5) Heat treatment to obtain Au / ReS2 substrate:

[0081] The hydrothermal reactor obtained in step (4) was placed in a thermostat and heated. After the temperature reached 200°C, the temperature was kept constant for 2 hours. Thereafter, the thermostat was slowly cooled to room temperature. The substrate was taken out from the hydrothermal reactor to obtain a 70nm Au / ReS2 substrate.

[0082] (6) Evaporation treatment to obtain a new type of SERS substrate of Au / ReS2 / Ag thin film:

[0083] The Au / ReS2 substrate obtained in step (5) is placed in a magnetron sputtering coating device, and a silver rake with a purity of 99.99% is used as the evaporation source. After evacuating to 8×10-6 Torr, the current rate is controlled to evaporate and a layer of Ag with a thickness of about 15 nm is deposited on a clean and flat substrate to obtain a new SERS substrate of Au / ReS2 / Ag thin film.

[0084] Example 4

[0085] This embodiment discloses a method for preparing a three-dimensional SERS substrate based on ReS2, which specifically includes the following steps:

[0086] (1) Cleaning of substrate:

[0087] A substrate made of single crystal silicon material is first placed in acetone and ultrasonically cleaned in an ultrasonic machine for fifteen minutes; then the substrate is placed in ethanol and ultrasonically cleaned in an ultrasonic machine for fifteen minutes; finally, the substrate is further placed in deionized water and ultrasonically cleaned in an ultrasonic machine for fifteen minutes to obtain a clean substrate. The substrate is made of pyramid silicon.

[0088] (2) Preparation of gold film:

[0089] The clean substrate obtained by cleaning in step (1) is placed in a magnetron sputtering coating device. A gold rake with a purity of 99.99% is used as the evaporation source. After evacuating to 8×10-6 Torr, the current rate is controlled to evaporate and a layer of Au film with a thickness of about 7 nm is deposited on the clean and flat substrate.

[0090] (3) Precursor fluid preparation:

[0091] Use a 1 / 10,000 balance to weigh a certain mass of ammonium perrhenate, hydroxylamine hydrochloride and L-cysteine ​​powder and put them into a container. Use a pipette to take deionized water and inject it into the container containing the mixed powder to prepare a precursor solution. Then put the precursor solution into an ultrasonic machine for ultrasonic treatment for 20 minutes to crush the mixed powder and form a uniform solution. Specifically, the concentration of ammonium perrhenate, hydroxylamine hydrochloride and L-cysteine ​​is 0.1M, the volume is 0.4-1ml, 3ml and 3ml respectively, and the volume of deionized water is 3ml.

[0092] (4) Transfer of precursor solution:

[0093] Use a pipette to transfer the precursor solution prepared in step 3 into a 25-500 ml hydrothermal reactor.

[0094] (5) Heat treatment to obtain Au / ReS2 substrate:

[0095] The hydrothermal reactor obtained in step (4) was placed in a thermostat and heated. After the temperature reached 200°C, the temperature was kept constant for 6 hours. Thereafter, the thermostat was slowly cooled to room temperature. The substrate was taken out from the hydrothermal reactor to obtain a 70nm Au / ReS2 substrate.

[0096] (6) Evaporation treatment to obtain a new type of SERS substrate of Au / ReS2 / Ag thin film:

[0097] The Au / ReS2 substrate obtained in step (5) is placed in a magnetron sputtering coating device, and a silver rake with a purity of 99.99% is used as the evaporation source. After evacuating to 8×10-6 Torr, the current rate is controlled to evaporate and a layer of Ag with a thickness of about 15 nm is deposited on a clean and flat substrate to obtain a new SERS substrate of Au / ReS2 / Ag thin film.

[0098] Example 5

[0099] This embodiment discloses a method for preparing a three-dimensional SERS substrate based on ReS2, which specifically includes the following steps:

[0100] (1) Cleaning of substrate:

[0101] A substrate made of single crystal silicon material is first placed in acetone and ultrasonically cleaned in an ultrasonic machine for fifteen minutes; then the substrate is placed in ethanol and ultrasonically cleaned in an ultrasonic machine for fifteen minutes; finally, the substrate is further placed in deionized water and ultrasonically cleaned in an ultrasonic machine for fifteen minutes to obtain a clean substrate. The substrate is made of pyramid silicon.

[0102] (2) Preparation of gold film:

[0103] The clean substrate obtained by cleaning in step (1) is placed in an ion plating device. A gold rake with a purity of 99.99% is used as the evaporation source. After evacuating to 8×10-6 Torr, the current rate is controlled to evaporate and a layer of Au film with a thickness of about 7 nm is deposited on the clean and flat substrate.

[0104] (3) Precursor fluid preparation:

[0105] Use a 1 / 10,000 balance to weigh a certain mass of ammonium perrhenate, hydroxylamine hydrochloride and L-cysteine ​​powder and put them into a container. Use a pipette to take deionized water and inject it into the container containing the mixed powder to prepare a precursor solution. Then put the precursor solution into an ultrasonic machine for ultrasonic treatment for 20 minutes to crush the mixed powder and form a uniform solution. Specifically, the concentration of ammonium perrhenate, hydroxylamine hydrochloride and L-cysteine ​​is 0.1M, the volume is 0.4-1ml, 3ml and 3ml respectively, and the volume of deionized water is 3ml.

[0106] (4) Transfer of precursor solution:

[0107] Use a pipette to transfer the precursor solution prepared in step 3 into a 25-500 ml hydrothermal reactor.

[0108] (5) Heat treatment to obtain Au / ReS2 substrate:

[0109] The hydrothermal reactor obtained in step (4) was placed in a thermostat and heated. After the temperature reached 200°C, the temperature was kept constant for 2 hours. Thereafter, the thermostat was slowly cooled to room temperature. The substrate was taken out from the hydrothermal reactor to obtain a 70nm Au / ReS2 substrate.

[0110] (6) Evaporation treatment to obtain a new type of SERS substrate of Au / ReS2 / Ag thin film:

[0111] The Au / ReS2 substrate obtained in step (5) is placed in an ion plating device, and a silver rake with a purity of 99.99% is used as the evaporation source. After evacuating to 8×10-6 Torr, the current rate is controlled to evaporate and a layer of Ag with a thickness of about 15 nm is deposited on the clean and flat substrate to obtain a new SERS substrate of Au / ReS2 / Ag thin film.

[0112] Example 6

[0113] This embodiment discloses a method for preparing a three-dimensional SERS substrate based on ReS2, which specifically includes the following steps:

[0114] (1) Cleaning of substrate:

[0115] A substrate made of single crystal silicon material is first placed in acetone and ultrasonically cleaned in an ultrasonic machine for fifteen minutes; then the substrate is placed in ethanol and ultrasonically cleaned in an ultrasonic machine for fifteen minutes; finally, the substrate is further placed in deionized water and ultrasonically cleaned in an ultrasonic machine for fifteen minutes to obtain a clean substrate. The substrate is made of pyramid silicon.

[0116] (2) Preparation of gold film:

[0117] The clean substrate obtained by cleaning in step (1) is placed in an ion plating device. A gold rake with a purity of 99.99% is used as the evaporation source. After evacuating to 8×10-6 Torr, the current rate is controlled to evaporate and a layer of Au film with a thickness of about 7 nm is deposited on the clean and flat substrate.

[0118] (3) Precursor fluid preparation:

[0119] Use a 1 / 10,000 balance to weigh a certain mass of ammonium perrhenate, hydroxylamine hydrochloride and L-cysteine ​​powder and put them into a container. Use a pipette to take deionized water and inject it into the container containing the mixed powder to prepare a precursor solution. Then put the precursor solution into an ultrasonic machine for ultrasonic treatment for 20 minutes to crush the mixed powder and form a uniform solution. Specifically, the concentration of ammonium perrhenate, hydroxylamine hydrochloride and L-cysteine ​​is 0.1M, the volume is 0.4-1ml, 3ml and 3ml respectively, and the volume of deionized water is 3ml.

[0120] (4) Transfer of precursor solution:

[0121] Use a pipette to transfer the precursor solution prepared in step 3 into a 25-500 ml hydrothermal reactor.

[0122] (5) Heat treatment to obtain Au / ReS2 substrate:

[0123] The hydrothermal reactor obtained in step (4) was placed in a thermostat and heated. After the temperature reached 200°C, the temperature was kept constant for 6 hours. Thereafter, the thermostat was slowly cooled to room temperature. The substrate was taken out from the hydrothermal reactor to obtain a 70nm Au / ReS2 substrate.

[0124] (6) Evaporation treatment to obtain a new type of SERS substrate of Au / ReS2 / Ag thin film:

[0125] The Au / ReS2 substrate obtained in step (5) is placed in an ion plating device, and a silver rake with a purity of 99.99% is used as the evaporation source. After evacuating to 8×10-6 Torr, the current rate is controlled to evaporate and a layer of Ag with a thickness of about 15 nm is deposited on the clean and flat substrate to obtain a new SERS substrate of Au / ReS2 / Ag thin film.

[0126] Figure 1 The scanning electron microscope image of the SERS substrate shows that: (1) the three-dimensional Au / ReS2 / Ag film is tightly attached to the surface of the substrate; (2) the prepared Ag nanoparticles are dense and relatively uniform in size.

[0127] Figure 2 is the Raman spectrum of the SERS substrate, from which it can be seen that: (1) there are characteristic peaks E2g, A1g and E1g of ReS2, which further proves that the Au / ReS2 / Ag thin film composite material is successfully prepared in this implementation case.

[0128] Figure 3 The Raman enhancement effect of the Au / ReS2 / Ag thin film novel SERS substrate prepared according to an embodiment of the present invention on the Rhodamine 6G molecule was compared, and it was found that the Au / ReS2 / Ag thin film substrate had an excellent SERS enhancement effect.

[0129] Figure 4 This is a temperature response Raman spectrum diagram of the Au / ReS2 / Ag thin film novel SERS substrate prepared according to an embodiment of the present invention. It is found that the Au / ReS2 / Ag thin film substrate has the strongest SERS response at an ambient temperature of 45°C.

[0130] The Au / ReS2 / Ag three-dimensional composite material substrate constructed by one or more of the above embodiments, wherein the presence of the Au film can effectively help the rhenium disulfide nanosheets to be adsorbed on the substrate, forming a three-dimensional nanocavity, providing sufficient adsorption area for Ag and the object to be detected, thereby significantly improving SERS. As for the temperature sensitivity, the temperature response behavior of SERS can further promote its application and promotion in practice.

[0131] Although the above describes the specific implementation mode of the present invention in conjunction with the accompanying drawings, it is not intended to limit the scope of protection of the present invention. Those skilled in the art should understand that various modifications or variations that can be made by those skilled in the art on the basis of the technical solution of the present invention without creative work are still within the scope of protection of the present invention.

Claims

1. A method for preparing a three-dimensional SERS substrate based on ReS2, characterized in that: The following steps are involved: A layer of Au thin film is evaporated on the substrate; ammonium perrhenate, hydroxylamine hydrochloride and L-cysteine ​​are mixed in deionized water to obtain a precursor solution; The substrate with the Au thin film evaporated thereon and the precursor solution are heated to obtain a substrate coated with Au / ReS2 composite nanosheets; A layer of Ag thin film is evaporated on the substrate coated with Au / ReS2 composite nanosheets to obtain a SERS substrate with Au / ReS2 / Ag composite structure; The ReS2-based three-dimensional SERS substrate comprises a substrate, and the surface of the substrate is sequentially coated with Au, ReS2 and Ag thin films.

2. The method for preparing a three-dimensional SERS substrate based on ReS2 according to claim 1, characterized in that: Before evaporating a layer of Au thin film on the substrate, the substrate is cleaned.

3. The method for preparing a three-dimensional SERS substrate based on ReS2 according to claim 1, characterized in that: The evaporation coating method adopts vacuum evaporation coating method, magnetron sputtering coating method or ion coating method.

4. The method for preparing a three-dimensional SERS substrate based on ReS2 according to claim 1, characterized in that: The Au film has a thickness of 7 nm.

5. The method for preparing a three-dimensional SERS substrate based on ReS2 according to claim 1, characterized in that: The concentrations of the ammonium perrhenate, hydroxylamine hydrochloride and L-cysteine ​​are all 0.1 M, and the volumes are 0.4-1 ml, 3 ml and 3 ml respectively, and the volume of deionized water is 3 ml.

6. The method for preparing a three-dimensional SERS substrate based on ReS2 according to claim 1, characterized in that: The substrate with the Au film evaporated thereon and the precursor solution are heated in a 25-500 ml hydrothermal reactor. After the temperature reaches 200°C, the temperature is kept constant for 2-6 hours, and then the temperature is slowly lowered to room temperature.

7. The method for preparing a three-dimensional SERS substrate based on ReS2 according to claim 1, characterized in that: The Ag film has a thickness of 15 nm.

8. A SERS sensor, characterized in that: It comprises a SERS substrate obtained by the preparation method as claimed in claim 1.

9. A SERS sensor system, characterized in that: Comprising the SERS sensor as claimed in claim 8.

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