阅读说明：本技术 一种具有双金属协同效应的多孔掺硼金刚石复合电极的制备方法及其检测葡萄糖的应用 (Preparation method of porous boron-doped diamond composite electrode with bimetal synergistic effect and application of porous boron-doped diamond composite electrode in detection of glucose ) 是由 朱嘉琦 姚凯丽 代兵 谭小俊 杨磊 孙明琪 高鸽 韩杰才 于 2019-09-27 设计创作，主要内容包括：一种具有双金属协同效应的多孔掺硼金刚石复合电极的制备方法及其检测葡萄糖的应用,它涉及一种多孔掺硼金刚石复合电极的制备方法及应用。本发明要解决现有不存在制备多孔掺硼金刚石复合电极的方法,现有利用掺硼金刚石电极非酶葡萄糖传感器检测葡萄糖灵敏度较低的问题。制备方法：一、掺硼金刚石薄膜的制备；二、溅射镀膜及退火处理。应用：用于检测葡萄糖。本发明用于具有双金属协同效应的多孔掺硼金刚石复合电极的制备及其检测葡萄糖的应用。(A preparation method of a porous boron-doped diamond composite electrode with a bimetal synergistic effect and an application thereof in detecting glucose relate to a preparation method and an application of a porous boron-doped diamond composite electrode. The invention aims to solve the problems that the existing method for preparing the porous boron-doped diamond composite electrode does not exist, and the existing boron-doped diamond electrode non-enzymatic glucose sensor is low in glucose detection sensitivity. The preparation method comprises the following steps: firstly, preparing a boron-doped diamond film; secondly, sputtering coating and annealing treatment. The application comprises the following steps: used for detecting glucose. The invention is used for preparing the porous boron-doped diamond composite electrode with the bimetal synergistic effect and the application thereof in detecting glucose.)

1. A preparation method of a porous boron-doped diamond composite electrode with a bimetal synergistic effect is characterized by comprising the following steps:

firstly, preparing a boron-doped diamond film:

placing a silicon wafer in a spin coater, dripping 2-15% by mass of nano-diamond suspension into the silicon wafer at a rotating speed of 500-2000 rpm, spin-coating for 3-6 times, and air-drying to obtain the silicon wafer spin-coated with the nano-diamond, placing the silicon wafer spin-coated with the nano-diamond and a graphite sheet on a sample stage of a microwave plasma chemical vapor deposition device in parallel, introducing hydrogen and diborane gas, and depositing for 60-30 hours under the conditions that the hydrogen flow rate is 100-500 sccm, the diborane gas flow rate is 1-20 sccm, the temperature of the silicon wafer spin-coated with the nano-diamond is 550-1000 ℃, the temperature of the graphite sheet is 650-1100 ℃, the pressure is 100-300 mbar, and the microwave power is 1800-4500W to obtain a substrate with a boron-doped diamond film deposited on the surface;

secondly, sputtering coating and annealing treatment:

placing the substrate with the boron-doped diamond film deposited on the surface in a multi-target magnetron sputtering device, sputtering for 2-20 min under the conditions that the sputtering power of a nickel target is 100-200W and the sputtering power of a gold target is 40-80W, co-depositing a gold/nickel bimetal mixed film with the thickness of 0.02-0.1 mu m on the boron-doped diamond film, then placing the boron-doped diamond film in a tubular furnace, heating to the temperature of 800-1000 ℃, preserving the heat for 1-3 h under the conditions that the argon atmosphere and the temperature are 800-1000 ℃, and then cooling to the room temperature to complete the preparation of the porous boron-doped diamond composite electrode with the bimetal synergistic effect.

2. The method according to claim 1, wherein the purity of the graphite sheet in the first step is 99.9%.

3. The method for preparing a porous boron-doped diamond composite electrode with a bimetal synergistic effect as claimed in claim 1, wherein the graphite sheet in the first step is a square sheet with the side length of 20 mm-60 mm and the thickness of 2 mm-5 mm.

4. The preparation method of the porous boron-doped diamond composite electrode with the bimetal synergistic effect according to claim 1, characterized in that in the step one, a silicon wafer is placed in a spin coater, under the condition that the rotating speed is 1000-2000 r/s, nano-diamond suspension with the mass percentage of 2-10% is dripped, spin coating is carried out for 3-6 times, and air drying is carried out, so that the silicon wafer with the nano-diamond spin coating is obtained.

5. The method for preparing a porous boron-doped diamond composite electrode with bimetal synergistic effect according to claim 1, characterized in that hydrogen gas and diborane gas are introduced in the first step, and deposition is carried out for 60min to 30h under the conditions that the hydrogen flow rate is 200sccm to 500sccm, the diborane gas flow rate is 2sccm to 20sccm, the temperature of the silicon wafer coated with the nano-diamond is 600 ℃ to 1000 ℃, the temperature of the graphite sheet is 700 ℃ to 1100 ℃, the pressure is 200mbar to 300mbar and the microwave power is 2000W to 4500W.

6. The method for preparing a porous boron-doped diamond composite electrode with bimetal synergistic effect according to claim 1, characterized in that in the second step, the substrate with the boron-doped diamond film deposited on the surface is placed in a multi-target magnetron sputtering device, under the condition that the sputtering power of a nickel target is 150W-200W and the sputtering power of a gold target is 50W-80W, the sputtering is carried out for 10 min-20 min, and the gold/nickel bimetal mixed film with the thickness of 0.02 μm-0.1 μm is co-deposited on the boron-doped diamond film.

7. The method for preparing a porous boron-doped diamond composite electrode with bimetal synergistic effect according to claim 1, characterized in that in the second step, the substrate with the boron-doped diamond film deposited on the surface is placed in a multi-target magnetron sputtering device, under the condition that the sputtering power of a nickel target is 100W-150W and the sputtering power of a gold target is 40W-50W, the sputtering is carried out for 2 min-10 min, and the gold/nickel bimetal mixed film with the thickness of 0.02 μm-0.1 μm is co-deposited on the boron-doped diamond film.

8. The method for preparing the porous boron-doped diamond composite electrode with the bimetal synergistic effect according to claim 1, wherein the porous boron-doped diamond composite electrode is placed in a tubular furnace in the second step, heated to 800-900 ℃, and kept at the temperature of 800-900 ℃ for 1-2 h under the argon atmosphere.

9. The method for preparing the porous boron-doped diamond composite electrode with the bimetal synergistic effect according to claim 1, wherein the porous boron-doped diamond composite electrode is placed in a tubular furnace in the second step, heated to 900-1000 ℃, and kept at the temperature of 900-1000 ℃ for 2-3 h under the argon atmosphere.

10. The application of the porous boron-doped diamond composite electrode with the bimetal synergistic effect prepared by the method of claim 1 in detecting glucose, wherein the porous boron-doped diamond composite electrode with the bimetal synergistic effect is used for detecting glucose, and the detection limit of the concentration of the detected glucose is 0.0026 mmol/L.

Technical Field

The invention relates to a preparation method and application of a porous boron-doped diamond composite electrode.

Background

Glucose plays an important role in the field of biology, and is an energy source and a metabolic intermediate product of living cells, namely a main energy supply substance of organisms. Various diseases of the human body are related to the glucose content in the body, such as diabetes. In addition, glucose is widely used in the field of candy production and the like. Therefore, the method has important significance for measuring the glucose content in the fields of biological medicine, food processing and the like. At present, a glucose detector mainly detects glucose by a glucose biosensor based on glucose oxidase. However, such sensors are expensive, sensitive to ambient temperature and humidity, and lack long-term stability.

In comparison, the boron-doped diamond material has the advantages of low price, good stability and the like when being used as a non-enzymatic glucose sensor. In addition, the boron-doped diamond material has good wear resistance, chemical stability, biocompatibility and some excellent electrochemical properties, such as lower background current, wider potential window, surface acid and alkali resistance and the like. Therefore, the boron-doped diamond electrode non-enzymatic glucose sensor has great application potential in detecting glucose. However, the electrochemical detection sensitivity of the boron-doped diamond electrode material is low, the glucose concentration is generally required to be not less than 0.25mmol/L, and in order to provide more accurate glucose concentration detection, the surface sensitivity of the boron-doped diamond needs to be improved.

Disclosure of Invention

The invention provides a preparation method of a porous boron-doped diamond composite electrode with a bimetal synergistic effect and application thereof in detecting glucose, aiming at solving the problems that the existing method for preparing the porous boron-doped diamond composite electrode does not exist and the existing glucose detection sensitivity by using a boron-doped diamond electrode non-enzymatic glucose sensor is low.

A preparation method of a porous boron-doped diamond composite electrode with a bimetal synergistic effect is carried out according to the following steps:

firstly, preparing a boron-doped diamond film:

placing a silicon wafer in a spin coater, dripping 2-15% by mass of nano-diamond suspension into the silicon wafer at a rotating speed of 500-2000 rpm, spin-coating for 3-6 times, and air-drying to obtain the silicon wafer spin-coated with the nano-diamond, placing the silicon wafer spin-coated with the nano-diamond and a graphite sheet on a sample stage of a microwave plasma chemical vapor deposition device in parallel, introducing hydrogen and diborane gas, and depositing for 60-30 hours under the conditions that the hydrogen flow rate is 100-500 sccm, the diborane gas flow rate is 1-20 sccm, the temperature of the silicon wafer spin-coated with the nano-diamond is 550-1000 ℃, the temperature of the graphite sheet is 650-1100 ℃, the pressure is 100-300 mbar, and the microwave power is 1800-4500W to obtain a substrate with a boron-doped diamond film deposited on the surface;

secondly, sputtering coating and annealing treatment:

placing the substrate with the boron-doped diamond film deposited on the surface in a multi-target magnetron sputtering device, sputtering for 2-20 min under the conditions that the sputtering power of a nickel target is 100-200W and the sputtering power of a gold target is 40-80W, co-depositing a gold/nickel bimetal mixed film with the thickness of 0.02-0.1 mu m on the boron-doped diamond film, then placing the boron-doped diamond film in a tubular furnace, heating to the temperature of 800-1000 ℃, preserving the heat for 1-3 h under the conditions that the argon atmosphere and the temperature are 800-1000 ℃, and then cooling to the room temperature to complete the preparation of the porous boron-doped diamond composite electrode with the bimetal synergistic effect.

The porous boron-doped diamond composite electrode with the bimetal synergistic effect is used for detecting glucose, and the detection limit of the concentration of the detected glucose is 0.0026 mmol/L.

The invention has the beneficial effects that:

the porous boron-doped diamond composite electrode with the bimetal synergistic effect is obtained by surface modification of bimetal gold and nickel and annealing. After annealing, the two metals change from a film form to a nano-aggregate form, mainly because the metals melt due to high temperature, and then the melted metals gradually solidify to form granular aggregates with the decrease of temperature. Meanwhile, the nickel has an etching effect on the boron-doped diamond, so that the surface of the composite electrode presents a porous structure under the high-temperature environment through the metal agglomeration and etching effects.

The principle of the double-metal synergistic effect lies in the good oxidation performance and biocompatibility of gold to glucose and the good catalytic performance of nickel to glucose, so that the sensitivity of boron-doped diamond to glucose detection is improved. And compared with flat boron-doped diamond, the obtained porous boron-doped diamond has larger surface area, namely the porous boron-doped diamond can be in more full contact with a glucose solution, and the detection of glucose is also facilitated.

The invention relates to a porous composite electrode sensor consisting of a boron-doped diamond film modified by gold and nickel bimetal, which is used for detecting the concentration of glucose. The detector shows a good linear relation with response current in the range of 0.02 mmol/L-9 mmol/L of glucose concentration, and the detection limit can reach 0.0026 mmol/L. The porous boron-doped diamond composite electrode with the bimetal synergistic effect has stronger oxidation-reduction property on glucose, and the current is reduced by less than 10 muA after the electrode is cycled for 30 circles by cyclic voltammetry, so that the porous boron-doped diamond composite electrode has higher stability.

The invention relates to a preparation method of a porous boron-doped diamond composite electrode with a bimetal synergistic effect and application of the porous boron-doped diamond composite electrode in detecting glucose.

Drawings

FIG. 1 is a surface topography map of a boron-doped diamond film deposited on a substrate surface as obtained in a first step of the embodiment;

FIG. 2 is a 20000 times enlarged surface topography of the porous boron-doped diamond composite electrode with bimetallic synergistic effect prepared in the first example;

FIG. 3 is a surface topography of the porous boron-doped diamond composite electrode with bimetal synergy prepared in the first example, which is amplified by 160000 times, 1 is a bare boron-doped diamond, and 2 is a gold/nickel double metal layer;

FIG. 4 is a comparison graph of Raman spectra, wherein a is a boron-doped diamond film deposited on the surface of the substrate obtained in the first step of the example, and b is a porous boron-doped diamond composite electrode with bimetal synergistic effect prepared in the first step of the example;

FIG. 5 is a comparison XRD plot; a is a boron-doped diamond film deposited on the surface of the substrate obtained in the first step of the embodiment, and b is a porous boron-doped diamond composite electrode with a bimetal synergistic effect prepared in the first step of the embodiment;

FIG. 6 is a comparison graph of cyclic voltammograms; a is a pure boron-doped diamond film electrode obtained in the first step of the embodiment, and b is a porous boron-doped diamond composite electrode with a bimetal synergistic effect prepared in the first step of the embodiment;

FIG. 7 is a 30-turn cyclic voltammogram of the porous boron-doped diamond composite electrode with bimetal synergistic effect prepared in the first example;

FIG. 8 is an enlarged view of area A of FIG. 7;

FIG. 9 is an ampere response curve of the porous boron-doped diamond composite electrode with bimetal synergistic effect prepared in the first example;

FIG. 10 is an enlarged view of area B of FIG. 9;

fig. 11 is a glucose concentration detection curve of the porous boron-doped diamond composite electrode with bimetal synergistic effect prepared in the first example.

Detailed Description