WO2020082655A1

WO2020082655A1 - Sers chip and methods for manufacturing and regenerating same

Info

Publication number: WO2020082655A1
Application number: PCT/CN2019/076350
Authority: WO
Inventors: 赵志刚; 丛杉
Original assignee: 中国科学院苏州纳米技术与纳米仿生研究所
Priority date: 2018-10-26
Filing date: 2019-02-27
Publication date: 2020-04-30
Also published as: CN111103278A

Abstract

Disclosed is a method for manufacturing an SERS chip. The manufacturing method comprises: using a magnetron sputtering process to manufacture and form a semiconductor oxide film on a conductive substrate; and regenerating the semiconductor oxide film by means of electrochemical charge-discharge technology, and obtaining an SERS chip. Further disclosed is an SERS chip obtained via the manufacturing method. Further disclosed is a method for regenerating a used SERS chip. The invention resolves common issues regarding currently existing precious-metal SERS chips such as high costs, a short shelf life, and poor cycle performance.

Description

SERS chip and its production and regeneration method

Technical field

The invention relates to the technical field of Raman scattering spectroscopy, in particular to a SERS chip and a method for manufacturing and regenerating it.

Background technique

Surface-enhanced Raman spectroscopy (SERS) is a promising surface spectroscopy technique that can be very effective in the qualitative and quantitative analysis of trace molecules through the interaction of molecules and substrate materials; it has high sensitivity and fingerprint , Fast and lossless. Therefore, the application value in the fields of food safety, explosive detection, art identification, biomedicine and so on is becoming increasingly prominent. SERS substrate is the key to obtain high-quality Raman signals, precious metals (Au, Ag, etc.) are the most widely used SERS substrate materials, Raman enhancement factor can reach the order of 10 ⁴ -10 ⁹ [Science 1997, 275, 1102- 1106]. At present, SERS chips based on fine nanostructures of precious metal materials have been marketed in many products, mostly in the form of "throw away after use", and most of them have a short shelf life, requiring "open to use"; the cost is too high, the stability is poor, and the reproduction Poor sex has become the main problem of user feedback, which is also the bottleneck of current SERS chip technology development and application development.

Recently, the study of semiconductor materials as SERS substrates has made great breakthroughs in theory and application [Chem.Rev.2016, 116, 14921-14981], a variety of semiconductor compounds (such as tungsten oxide, molybdenum oxide, copper oxide, etc.) have been It is proved to have SERS performance close to that of noble metal materials, with a Raman enhancement factor of the order of 10 ^6. Compared with noble metal materials, it has the advantages of simple preparation, low cost, good stability, and wider application fields. The product is available. Therefore, based on semiconductor materials, the new SERS chips developed will have the opportunity to meet the demands of a wider user group and inject new vitality into the SERS chip market.

Summary of the invention

In view of the shortcomings of the prior art, the present invention provides the following solutions.

An aspect of the present invention provides a method for manufacturing a SERS chip. The manufacturing method includes:

A magnetron sputtering process is used to form a semiconductor oxide film on a conductive substrate;

The semiconductor oxide film is activated by means of electrochemical charge and discharge to obtain a SERS chip.

Optionally, the conductive substrate includes a non-conductive substrate layer and a conductive material disposed on the non-conductive substrate layer.

Optionally, a method for forming a semiconductor oxide film on a conductive substrate using a magnetron sputtering process includes:

Place the fully cleaned conductive substrate in the cavity of the magnetron sputtering equipment;

Select the corresponding target material and the corresponding RF power supply or DC power supply;

Argon gas is used as an ion source, a predetermined amount of oxygen gas is introduced, and a sputtering reaction is performed under a predetermined temperature and a predetermined time to form a semiconductor oxide film on a conductive substrate.

Optionally, in the magnetron sputtering process, the target material used is made of any one of titanium, vanadium, chromium, manganese, iron, cobalt, nickel, copper, zinc, molybdenum, and tungsten, or used The target material is made of any oxide of titanium, vanadium, chromium, manganese, iron, cobalt, nickel, copper, zinc, molybdenum, and tungsten.

Optionally, the method of activating the semiconductor oxide film by means of electrochemical charging and discharging includes:

Put the conductive substrate and the semiconductor oxide film on it as the working electrode in the electrolyte solution;

Constant voltage charge and discharge in the electrolyte solution to activate the semiconductor oxide film.

Optionally, the electrolyte solution includes hydrochloric acid, sulfuric acid, lithium chloride, sodium chloride, magnesium chloride, aluminum chloride, lithium perchlorate, sodium perchlorate, magnesium perchlorate, aluminum perchlorate, potassium hydroxide , Any of sodium hydroxide.

Optionally, the constant voltage is -0.9V to 0.9V.

Another aspect of the present invention provides a SERS chip manufactured by the above manufacturing method.

Yet another aspect of the present invention provides a regeneration method of the above SERS chip, the regeneration method includes:

Placing the used SERS chip as a working electrode in an electrolyte solution;

A constant voltage charge and discharge is performed in the electrolyte solution to regenerate the SERS chip.

Optionally, the electrolyte solution includes hydrochloric acid, sulfuric acid, lithium chloride, sodium chloride, magnesium chloride, aluminum chloride, lithium perchlorate, sodium perchlorate, magnesium perchlorate, aluminum perchlorate, potassium hydroxide , Sodium hydroxide; and / or the constant voltage is -0.9V to 0.9V.

Compared with the prior art, the SERS chip of the present invention has the advantages of simple manufacturing process, low cost, wide range of applicable materials, and easy mass production. Moreover, when it is used, product activation is performed by simple electrochemical treatment, which has a comparative Long storage time. Further, the used SERS chip of the present invention can be regenerated by electrolytic charging and discharging, thereby achieving the purpose of "recycling".

BRIEF DESCRIPTION

FIG. 1 is an enhanced Raman spectrum diagram of probe molecules with different concentrations in a SERS chip in Example 1 of the present invention;

2 is a graph of the SERS signal intensity distribution of a 2 × 2 mm area randomly selected on the SERS chip in Embodiment 1 of the present invention;

3 is a data table of SERS signal intensity of samples from different batches of the SERS chip to the same probe molecule in Example 1 of the present invention;

4 is a performance data table of the SERS chip after cyclic regeneration in Embodiment 4 of the present invention;

FIG. 5 is a performance comparison table of SERS chips before and after electrochemical activation in Example 3 of the present invention.

detailed description

To make the objectives, technical solutions, and advantages of the present invention clearer, specific embodiments of the present invention are described in detail below with reference to the drawings. Examples of these preferred embodiments are illustrated in the drawings. The embodiments of the present invention shown in the drawings and described according to the drawings are merely exemplary, and the present invention is not limited to these embodiments.

Here, it should also be noted that, in order to avoid obscuring the present invention due to unnecessary details, only the structures and / or processing steps closely related to the solution according to the present invention are shown in the drawings, and the Other details of the invention are not relevant.

The invention discloses a method for manufacturing a SERS chip based on semiconductor materials. The manufacturing method of the SERS chip includes:

Step S1, a magnetron sputtering process is used to form a semiconductor oxide film on the conductive substrate. Wherein, the conductive substrate includes a non-conductive substrate layer and a conductive material disposed on the non-conductive substrate layer, or the conductive material itself can be used as the conductive substrate (for example: carbon material, metal, polymer, FTO, ITO, etc. Conductive materials).

Specifically, a method for forming a semiconductor oxide film on a conductive substrate includes:

Argon gas is used as the ion source, and a predetermined amount of oxygen (volume ratio of oxygen and argon gas: 1: 1 to 1:10) is introduced at a predetermined temperature (200 to 500 ° C) and a predetermined time condition (20 to 120min) ) To perform a sputtering reaction to form a semiconductor oxide film on a conductive substrate.

Specifically, in the magnetron sputtering process, the target material used is made of any one of titanium, vanadium, chromium, manganese, iron, cobalt, nickel, copper, zinc, molybdenum, and tungsten, or the target used The material is made of any oxide of titanium, vanadium, chromium, manganese, iron, cobalt, nickel, copper, zinc, molybdenum, and tungsten.

Step S2: Activate the semiconductor oxide film by means of electrochemical charging and discharging to obtain a SERS chip.

Specifically, the conductive substrate and the semiconductor oxide film thereon are placed in the electrolyte solution as working electrodes;

Constant voltage charge and discharge in the electrolyte solution to activate the semiconductor oxide film. Wherein, the constant voltage is -0.9V to 0.9V, and the electrolyte solution includes hydrochloric acid, sulfuric acid, lithium chloride, sodium chloride, magnesium chloride, aluminum chloride, lithium perchlorate, sodium perchlorate, magnesium perchlorate, Any one of aluminum perchlorate, potassium hydroxide, and sodium hydroxide.

Based on the above basic steps, the following describes the manufacturing process of the SERS chip through specific embodiments.

Example 1

After fully washing and drying the FTO conductive glass, it is placed in a magnetron sputtering chamber, using metal tungsten or tungsten oxide as the target, the ratio of O ₂ / Ar is 1:10, the DC voltage is 300W, and the coating is 20 minutes to obtain conductive glass Substrate tungsten oxide SERS chip.

Next, the above SERS chip is used as the working electrode, the Pt electrode is used as the counter electrode, the Ag / AgCl electrode is used as the reference electrode, and the 1M NaCl is used as the electrolyte, and the constant voltage -0.3V is discharged for 600s to complete the activation of the SERS chip to obtain SERS. chip.

Example 2

After fully washing and drying the FTO conductive glass, it is placed in a magnetron sputtering chamber, using metallic titanium or titanium oxide as the target material, the ratio of O ₂ / Ar is 3:10, the RF voltage is 300W, and the coating is 60 minutes to obtain conductive glass. Substrate titanium oxide SERS chip.

Next, use the SERS chip as the working electrode, the Pt electrode as the counter electrode, the Ag / AgCl electrode as the reference electrode, 1M HCl as the electrolyte, and the constant voltage -0.9V discharge for 300s to complete the activation of the SERS chip to obtain SERS. chip.

Example 3

After fully washing and drying the FTO-PET flexible conductive substrate, it is placed in a magnetron sputtering chamber, using metal nickel or nickel oxide as the target material, the ratio of O ₂ / Ar is 1:10, the RF voltage is 100W, and the coating is 20 minutes. A nickel oxide SERS chip with a conductive glass substrate was obtained.

Next, the above SERS chip is used as the working electrode, the Pt electrode is used as the counter electrode, the Ag / AgCl electrode is used as the reference electrode, and 1M KOH is used as the electrolyte, and the constant voltage + 0.8V is charged for 100s to complete the activation of the SERS chip to obtain SERS. chip.

The invention also discloses the regeneration method of the used SERS chip, the regeneration method includes:

Step S1, placing the used SERS chip as a working electrode in an electrolyte solution.

Step S2: Charge and discharge a constant voltage in the electrolyte solution to regenerate the SERS chip. Among them, the electrolyte solution includes hydrochloric acid, sulfuric acid, lithium chloride, sodium chloride, magnesium chloride, aluminum chloride, lithium perchlorate, sodium perchlorate, magnesium perchlorate, aluminum perchlorate, potassium hydroxide, sodium hydroxide Any one of; and / or the constant voltage is -0.9V to 0.9V

Based on the above basic steps, the following describes the regeneration process of the SERS chip through specific embodiments.

Example 4

The recovered tungsten oxide SERS chip (the chip of Example 1) was thoroughly washed and dried to remove the residual probe molecules from the previous test, and used as the working electrode again, the Pt electrode as the counter electrode, and the Ag / AgCl electrode as the reference electrode. 1M NaCl is used as the electrolyte, and discharged at -0.3V for 600s to complete the regeneration of the SERS chip.

Example 5

The recovered titanium oxide SERS chip (the chip of Example 2) was thoroughly washed and dried to remove the residual probe molecules from the previous test, and used again as the working electrode, Pt electrode as the counter electrode, and Ag / AgCl electrode as the reference electrode, to 1M HCl is used as the electrolyte, and the constant voltage -0.9V discharges for 300s to complete the regeneration of the SERS chip.

Example 6

The recovered nickel oxide SERS chip (the chip of Example 3) was thoroughly washed and dried to remove the residual probe molecules from the previous test, and used as the working electrode again, the Pt electrode as the counter electrode, and the Ag / AgCl electrode as the reference electrode. 1M KOH is used as the electrolyte, and the constant voltage + 0.8V is charged for 100s to complete the regeneration of the SERS chip.

The advantages of the SERS chip of the present invention are explained below with the accompanying drawings.

As shown in FIG. 1, the enhanced Raman spectrum of the SERS chip in Example 1 for different concentrations of probe molecules. Taking the dye molecule rhodamine 6G (R6G) as an example, the concentrations are 10 ^-6 , 10 ^-5 , and 10 ^-4 M, respectively. The laser wavelength is 532nm; the ordinate is the Raman signal intensity, and the abscissa corresponds to the peak position of the Raman spectrum line.

As shown in FIG. 2, the SERS signal intensity distribution in the 2 × 2 mm region randomly selected on the SERS chip in Example 1 is uniform.

As shown in FIG. 3, the SERS signal intensity of the sample to the same probe molecule in different batches of the SERS chip in Example 1 is relatively uniform. The ordinate is the average intensity of Raman signal, and the abscissa is the base number.

According to the experimental results of FIGS. 1 to 3, the SERS chip of the present invention has sufficient performance to replace the precious metal SERS chip in the market, and the SERS chip of the present invention has the advantages of simple preparation and low cost.

As shown in FIG. 4, the SERS performance of the SERS chip in Example 4 can be maintained after 5 cycles of use; the ordinate is the average intensity of the Raman signal, and the abscissa is the number of cycles. It can be seen from this that, compared with the "throw-and-use" SERS chip in the market, the SERS chip of the present invention can be recycled many times, which improves the life of the SERS chip, reduces the application cost of the SERS chip, and further reduces The waste of precious metals.

As shown in FIG. 5, the SERS performance of the SERS chip of Example 3 after electrochemical activation is compared. Taking R6G as an example, the laser wavelength is 532 nm; the ordinate is the Raman signal intensity, and the abscissa is the peak position of the Raman spectrum line. Thus, it can be seen that the SERS chip of the present invention has low performance and slow response before activation, so the SERS chip of the present invention has a longer shelf life than the precious metal SERS chip in the market.

Although the embodiments of the present invention have been shown and described, those of ordinary skill in the art can understand that various changes, modifications, and substitutions can be made to these embodiments without departing from the principle and spirit of the present invention And variations, the scope of the invention is defined by the appended claims and their equivalents.

Claims

A manufacturing method of a SERS chip, wherein the manufacturing method includes:

A magnetron sputtering process is used to form a semiconductor oxide film on a conductive substrate;

The semiconductor oxide film is activated by means of electrochemical charge and discharge to obtain a SERS chip.
The manufacturing method according to claim 1, wherein the conductive substrate comprises a non-conductive substrate layer and a conductive material disposed on the non-conductive substrate layer.
The manufacturing method according to claim 1, wherein the method for forming a semiconductor oxide film on the conductive substrate using a magnetron sputtering process includes:

Place the fully cleaned conductive substrate in the cavity of the magnetron sputtering equipment;

Select the corresponding target material and the corresponding RF power supply or DC power supply;

Argon gas is used as an ion source, a predetermined amount of oxygen gas is introduced, and a sputtering reaction is performed under a predetermined temperature and a predetermined time to form a semiconductor oxide film on a conductive substrate.
The manufacturing method according to claim 3, wherein in the magnetron sputtering process, the target material used is titanium, vanadium, chromium, manganese, iron, cobalt, nickel, copper, zinc, molybdenum, tungsten Either one is made or formed, or the target material used is made of any one of oxides of titanium, vanadium, chromium, manganese, iron, cobalt, nickel, copper, zinc, molybdenum, and tungsten.
The manufacturing method according to claim 2, wherein the method for forming a semiconductor oxide film on the conductive substrate by using a magnetron sputtering process includes:

Place the fully cleaned conductive substrate in the cavity of the magnetron sputtering equipment;

Select the corresponding target material and the corresponding RF power supply or DC power supply;

Argon gas is used as an ion source, a predetermined amount of oxygen gas is introduced, and a sputtering reaction is performed under a predetermined temperature and a predetermined time to form a semiconductor oxide film on a conductive substrate.
The manufacturing method according to claim 5, wherein in the magnetron sputtering process, the target material used is titanium, vanadium, chromium, manganese, iron, cobalt, nickel, copper, zinc, molybdenum, tungsten Either one is made or formed, or the target material used is made of any one of oxides of titanium, vanadium, chromium, manganese, iron, cobalt, nickel, copper, zinc, molybdenum, and tungsten.
The manufacturing method according to claim 1, wherein the method of activating the semiconductor oxide film by electrochemical charging and discharging includes:

Put the conductive substrate and the semiconductor oxide film on it as the working electrode in the electrolyte solution;

Constant voltage charge and discharge in the electrolyte solution to activate the semiconductor oxide film.
The production method according to claim 7, wherein the electrolyte solution comprises hydrochloric acid, sulfuric acid, lithium chloride, sodium chloride, magnesium chloride, aluminum chloride, lithium perchlorate, sodium perchlorate, magnesium perchlorate, Any one of aluminum perchlorate, potassium hydroxide, and sodium hydroxide.
The manufacturing method according to claim 7, wherein the constant voltage is -0.9V to 0.9V.
The manufacturing method according to claim 2, wherein the method of activating the semiconductor oxide film by electrochemical charging and discharging includes:

Put the conductive substrate and the semiconductor oxide film on it as the working electrode in the electrolyte solution;

Constant voltage charge and discharge in the electrolyte solution to activate the semiconductor oxide film.
The manufacturing method according to claim 10, wherein the electrolyte solution comprises hydrochloric acid, sulfuric acid, lithium chloride, sodium chloride, magnesium chloride, aluminum chloride, lithium perchlorate, sodium perchlorate, magnesium perchlorate, Any one of aluminum perchlorate, potassium hydroxide, and sodium hydroxide.
The manufacturing method according to claim 10, wherein the constant voltage is -0.9V to 0.9V.
A SERS chip manufactured by the manufacturing method of claim 1.
A method for regenerating a SERS chip according to claim 13, wherein the method includes:

Placing the used SERS chip as a working electrode in an electrolyte solution;

A constant voltage charge and discharge is performed in the electrolyte solution to regenerate the SERS chip.
The regeneration method according to claim 14, wherein the electrolyte solution includes hydrochloric acid, sulfuric acid, lithium chloride, sodium chloride, magnesium chloride, aluminum chloride, lithium perchlorate, sodium perchlorate, magnesium perchlorate, Any one of aluminum perchlorate, potassium hydroxide, and sodium hydroxide.
The regeneration method according to claim 14, wherein the constant voltage is -0.9V to 0.9V.