技术问题technical problem
针对现有技术的不足,本发明目的是提供一种高比表面积的图案化掺硼金刚石电极及其制备方法和应用。本发明中所采用的图案化的制备方法属于自下而上的方法,即直接通过图案化的掩模与基底的一体连接,然后直接在基底上生长出图案化的金刚石电极。该方法设计步骤较刻蚀等方法更简单,操作更容易控制,制作成本也更低。In view of the shortcomings of the prior art, the purpose of the present invention is to provide a patterned boron-doped diamond electrode with a high specific surface area, and a preparation method and application thereof. The patterned preparation method used in the present invention belongs to a bottom-up method, that is, a patterned mask is directly connected to the substrate as a whole, and then a patterned diamond electrode is directly grown on the substrate. This method has simpler design steps than etching and other methods, easier operation control, and lower manufacturing cost.
技术解决方案Technical solutions
本发明一种高比表面积的图案化掺硼金刚石电极的制备方法,包括如下步骤。The method for preparing a patterned boron-doped diamond electrode with high specific surface area of the present invention includes the following steps.
将具有通孔图案的金属片覆盖在衬底表面,然后共同置于化学气相沉积炉中,于衬底表面的暴露部份沉积生长图案化掺硼金刚石层即得图案化掺硼金刚石电极,化学气相沉积过程中,控制衬底的表面温度为750-950℃,生长气压为2.5-5KPa,通入的甲烷、硼烷、氢气的比例为1-20: 0.3-1: 45-49。Cover the surface of the substrate with a metal sheet with a through-hole pattern, and then place it in a chemical vapor deposition furnace, and deposit and grow a patterned boron-doped diamond layer on the exposed part of the substrate surface to obtain a patterned boron-doped diamond electrode. During the vapor deposition process, the surface temperature of the substrate is controlled to be 750-950°C, the growth pressure is 2.5-5KPa, and the ratio of methane, borane, and hydrogen introduced is 1-20: 0.3-1: 45-49.
在本发明中,衬底表面的暴露部份是指衬底表面覆盖了具有通孔图案的金属片后,暴露出来的通孔图案部份。In the present invention, the exposed part of the surface of the substrate refers to the part of the through hole pattern exposed after the surface of the substrate is covered with a metal sheet with a through hole pattern.
本发明一种高比表面积的图案化掺硼金刚石电极的制备方法,将具有通孔图案的金属片覆盖在衬底表面,然后共同置于化学气相沉积炉中,采用基台限位固定。The invention provides a method for preparing a patterned boron-doped diamond electrode with a high specific surface area. A metal sheet with a through hole pattern is covered on the surface of a substrate, and then they are placed in a chemical vapor deposition furnace together and fixed by a base plate.
在实际操作过程中,基台的设计方式如下:如电极所需的实际尺寸2-10 cm
2,设计化学气相沉积的基台尺寸为4-15 cm
2,富余尺寸为固定时所需的余量尺寸,使用耐高温的钼金属线切割成相应尺寸的基台配件并完成组装。
In the actual operation process, the design method of the abutment is as follows: For example, the actual size of the electrode is 2-10 cm 2 , the size of the abutment designed for chemical vapor deposition is 4-15 cm 2 , and the surplus size is the surplus required for fixing. Measure the size, use high temperature resistant molybdenum wire to cut into corresponding size abutment accessories and complete the assembly.
本发明一种高比表面积的图案化掺硼金刚石电极的制备方法,所述金属片为不锈钢片。The invention provides a method for preparing a patterned boron-doped diamond electrode with a high specific surface area. The metal sheet is a stainless steel sheet.
本发明一种高比表面积的图案化掺硼金刚石电极的制备方法,所述具有通孔图案的金属片的制备过程为:根据所需的图案,采用光刻法在金属片表面刻蚀出对应的通孔图案。The present invention is a method for preparing a patterned boron-doped diamond electrode with a high specific surface area. The preparation process of the metal sheet with a through-hole pattern is: according to the required pattern, a photolithography method is used to etch the corresponding surface of the metal sheet. Through hole pattern.
本发明一种高比表面积的图案化掺硼金刚石电极的制备方法,所述图案为正方形阵列图形、长方形阵列图形、圆形阵列图形中的一种。The invention provides a method for preparing a patterned boron-doped diamond electrode with a high specific surface area. The pattern is one of a square array pattern, a rectangular array pattern, and a circular array pattern.
本发明一种高比表面积的图案化掺硼金刚石电极的制备方法,所述衬底为硅片。在本发明中,生长金刚石的基底采用的是能形成稳定氧化物中间层的硅基底,硅基底相较于其他金属类基底,能够形成热膨胀系数较纯基底更小的中间氧化物层,这样生长的金刚石就不容易脱落。The invention provides a method for preparing a patterned boron-doped diamond electrode with a high specific surface area. The substrate is a silicon wafer. In the present invention, the substrate for growing diamond is a silicon substrate that can form a stable oxide intermediate layer. Compared with other metal substrates, the silicon substrate can form an intermediate oxide layer with a smaller thermal expansion coefficient than that of a pure substrate. The diamond is not easy to fall off.
本发明一种高比表面积的图案化掺硼金刚石电极的制备方法,将具有通孔图案的金属片覆盖在衬底表面,然后共同置于化学气相沉积炉中,然后采用5-20℃/min,优选为5-15℃/min的速率升温使衬底的表面温度达到750-950℃。The present invention is a method for preparing a patterned boron-doped diamond electrode with a high specific surface area. A metal sheet with a through hole pattern is covered on the surface of a substrate, and then placed in a chemical vapor deposition furnace, and then 5-20°C/min Preferably, the temperature is increased at a rate of 5-15°C/min to make the surface temperature of the substrate reach 750-950°C.
发明人发现,通过将衬底进行四周限位固定以及通过缓慢的升温方式可以避免由于金属片与衬底因为热膨胀的不同,而导致出现由于金属片出现移位、变形等现象,导致生长的金刚石图案不规则甚至生长失败。The inventor found that by limiting and fixing the substrate around and slowly raising the temperature, the difference in thermal expansion between the metal sheet and the substrate can be avoided. The pattern is irregular or even fails to grow.
本发明一种高比表面积的图案化掺硼金刚石电极的制备方法,所述化学气相沉积为热丝化学气相沉积,热丝匝数为10-15匝,化学气相沉积过程中,控制热丝温度为2100-2400 ℃。The invention provides a method for preparing a patterned boron-doped diamond electrode with a high specific surface area. The chemical vapor deposition is hot wire chemical vapor deposition, the number of turns of the hot wire is 10-15, and the temperature of the hot wire is controlled during the chemical vapor deposition process. It is 2100-2400 ℃.
本发明一种高比表面积的图案化掺硼金刚石电极的制备方法,化学沉积过程中,首先通入的甲烷、硼烷、氢气的比例为
10-20: 0.3-1:
45-49,沉积1-2 h,然后再调节通入的甲烷、硼烷、氢气的比例为 2-5: 0.3-1: 45-49,沉积6-10h。The present invention is a method for preparing a patterned boron-doped diamond electrode with a high specific surface area. During the chemical deposition process, the ratio of methane, borane, and hydrogen introduced first is
10-20: 0.3-1:
45-49, deposition for 1-2 h, and then adjust the ratio of methane, borane, and hydrogen to 2-5: 0.3-1: 45-49, deposition for 6-10 h.
由于图案化生长的区域范围较传统的整块基底生长区域来说很小,生长过程中存在形核困难的问题。这主要是因为碳原子在形核、成岛、成膜等一系列过程中,需要足够的热力学运动来完成,但是限定了碳原子在特定区域内生长,肯定会相应增加形核和成膜难度,延长整个生长周期;发明人发现,通过采用生长初期高甲烷浓度的方法可以克服形核困难的问题。Since the area of patterned growth is smaller than that of the traditional monolithic substrate growth area, there is a problem of difficulty in nucleation during the growth process. This is mainly because carbon atoms need sufficient thermodynamic motion to complete a series of processes such as nucleation, island formation, and film formation. However, the growth of carbon atoms in a specific area is limited, which will definitely increase the difficulty of nucleation and film formation. , Prolong the entire growth cycle; the inventor found that the problem of difficulty in nucleation can be overcome by adopting the method of high methane concentration in the early stage of growth.
在实际操作过程中,先将具有通孔图案的金属片和硅片衬底均放置于丙酮溶液中,超声清洗10-20分钟,去除表面油渍;然后在去离子水中超声清洗5-20分钟,烘干后再进行沉积。In the actual operation process, first place the metal sheet with the through-hole pattern and the silicon wafer substrate in the acetone solution, and ultrasonically clean for 10-20 minutes to remove the surface oil stains; then ultrasonically clean in deionized water for 5-20 minutes. Deposit after drying.
本发明一种高比表面积的图案化掺硼金刚石电极的制备方法,所述掺硼金刚石层的厚度为5-20µm,所述掺硼金刚石层中金刚石的晶粒直径为5-10µm。The invention provides a method for preparing a patterned boron-doped diamond electrode with a high specific surface area. The thickness of the boron-doped diamond layer is 5-20 µm, and the diameter of the diamond grains in the boron-doped diamond layer is 5-10 µm.
作为优选,本发明一种高比表面积的图案化掺硼金刚石电极的制备方法,所述掺硼金刚石层为多孔硼掺杂金刚石层,所述多孔硼掺杂金刚石层通过沉积生长图案化掺硼金刚石层后,再进行高温刻蚀处理获得,所述高温刻蚀处理为高温气氛刻蚀处理或高温金属刻蚀处理。Preferably, the method for preparing a patterned boron-doped diamond electrode with a high specific surface area according to the present invention, the boron-doped diamond layer is a porous boron-doped diamond layer, and the porous boron-doped diamond layer is patterned by deposition and growth. After the diamond layer, it is obtained by high-temperature etching treatment. The high-temperature etching treatment is a high-temperature atmosphere etching treatment or a high-temperature metal etching treatment.
通过将掺硼金刚石层进行高温刻蚀处理,使得掺硼金刚石层形成多孔结构,即使掺硼金刚石层表面分布微孔和/或尖锥,从而进一步扩大图案化掺硼金刚石电极的比表面积。By subjecting the boron-doped diamond layer to high-temperature etching treatment, the boron-doped diamond layer forms a porous structure, even if micropores and/or sharp cones are distributed on the surface of the boron-doped diamond layer, thereby further expanding the specific surface area of the patterned boron-doped diamond electrode.
在实际操作过程中,高温气氛刻蚀处理是指将衬底表面的暴露部份沉积生长图案化掺硼金刚石层后,再置于空气或氢气气氛下,进行热处理,其中热处理的温度为600-1000℃,压强为10Pa-10
5Pa,处理时间为5~180min。
In the actual operation process, the high-temperature atmosphere etching treatment refers to depositing and growing the patterned boron-doped diamond layer on the exposed part of the substrate surface, and then placing it in an air or hydrogen atmosphere for heat treatment. The heat treatment temperature is 600- 1000℃, the pressure is 10Pa-10 5 Pa, the treatment time is 5~180min.
高温金属处理刻蚀是指,是指将衬底表面的暴露部份沉积生长图案化掺硼金刚石层后,再于掺硼金刚石层表面沉积对碳具有较高催化能力的金属层,然后对已沉积金属层的硼掺杂金刚石层进行热处理,使金属层在高温下球化,在金刚石表面形成弥撒分布的金属纳米球或微米球;在高温下,金刚石中的碳原子不断固溶到金属纳米球或微米球中,再通过添加氢气气氛刻蚀金属纳米球或微米球中碳原子过饱和固溶时析出的固体碳,使金属纳米球或微米球不断向金刚石内部迁移,最终在掺硼金刚石层表面形成大量的微孔和尖锥;所述金属层材料选自金属铁、钴、镍中的一种或复合;热处理温度为600-1000℃,时间1min-3h,压强为0.1-1个大气压。High-temperature metal treatment etching refers to depositing and growing a patterned boron-doped diamond layer on the exposed part of the substrate surface, and then depositing a metal layer with a higher catalytic ability for carbon on the surface of the boron-doped diamond layer, and then treating the surface of the substrate. The boron-doped diamond layer of the deposited metal layer is heat treated to spheroidize the metal layer at high temperature, forming a mass-distributed metal nanosphere or microsphere on the surface of the diamond; at high temperature, the carbon atoms in the diamond continuously dissolve into the metal nanometer In the spheres or microspheres, the solid carbon precipitated when the carbon atoms in the metal nanospheres or microspheres are supersaturated and solid-solved is etched by adding hydrogen atmosphere, so that the metal nanospheres or microspheres continue to migrate into the diamond, and finally the boron-doped diamond A large number of micropores and sharp cones are formed on the surface of the layer; the material of the metal layer is selected from one or a combination of metal iron, cobalt, and nickel; the heat treatment temperature is 600-1000°C, the time is 1min-3h, and the pressure is 0.1-1 Atmospheric pressure.
本发明还提供采用上述制备方法所制备的高比表面积的图案化掺硼金刚石电极。The invention also provides a patterned boron-doped diamond electrode with a high specific surface area prepared by the above-mentioned preparation method.
本发明还提供采用上述制备方法所制备的高比表面积的图案化掺硼金刚石电极作为工作电极应用于电化学传感器。The invention also provides a patterned boron-doped diamond electrode with a high specific surface area prepared by the above preparation method as a working electrode and applied to an electrochemical sensor.
在应用过程中,以掺硼金刚石电极作为工作电极,铂片作为对电极, Ag/AgCl电极作为参比电极组装成电化学传感器(三电极检测传感器)。In the application process, the boron-doped diamond electrode is used as the working electrode, the platinum sheet is used as the counter electrode, and the Ag/AgCl electrode is used as the reference electrode to form an electrochemical sensor (three-electrode detection sensor).
有益效果Beneficial effect
本发明中提供了一种高比表面积的图案化掺硼金刚石电极的制备方法,本发明的制备方法属于自下而上的方法,即直接通过图案化的掩模与基底的一体连接,然后直接在基底上生长出图案化的金刚石电极,该方法设计步骤较刻蚀等方法更简单,操作更容易控制,制作成本也更低。The present invention provides a method for preparing a patterned boron-doped diamond electrode with a high specific surface area. The preparation method of the present invention belongs to a bottom-up method, that is, directly connect the patterned mask to the substrate directly, and then directly A patterned diamond electrode is grown on the substrate. The method has simpler design steps than etching and other methods, easier to control the operation, and lower manufacturing cost.
在制备过程中,一是由于直接采用不锈钢片作为掩模覆盖硅基底,而作为掩模的不锈钢覆盖层热膨胀系数相比于硅基底大出很多,这样在高温生长时就容易导致原本固定好的掩模出现移位、变形等现象,导致生长的金刚石图案不规则甚至生长失败。在本发明中巧妙的设计了四周限位固定与缓慢升温相结合的方法来避免上述现象的发生。In the preparation process, one is that the stainless steel sheet is directly used as a mask to cover the silicon substrate, and the coefficient of thermal expansion of the stainless steel coating layer as a mask is much larger than that of the silicon substrate, so that it is easy to cause the original fixed during high temperature growth. The mask appears to be shifted, deformed, etc., resulting in irregular growth of the diamond pattern or even growth failure. In the present invention, a method combining the surrounding limit fixation and the slow temperature rise is cleverly designed to avoid the occurrence of the above phenomenon.
二是由于图案化生长的区域范围较传统的整块基底生长区域来说很小,生长过程中存在形核困难的问题。这主要是因为碳原子在形核、成岛、成膜等一系列过程中,需要足够的热力学运动来完成,但是限定了碳原子在特定区域内生长,从而相应增加了形核和成膜难度,延长整个生长周期,甚至无法形成规则的图案,本发明通过生长初期采用高甲烷浓度的方法从而克服了形核困难的问题。Second, because the patterned growth area is smaller than the traditional monolithic substrate growth area, there is a problem of difficulty in nucleation during the growth process. This is mainly because carbon atoms need sufficient thermodynamic motion to complete a series of processes such as nucleation, island formation, and film formation, but the growth of carbon atoms in a specific area is limited, which increases the difficulty of nucleation and film formation. , Prolong the entire growth cycle, even unable to form a regular pattern, the present invention overcomes the problem of difficulty in nucleation by adopting a method of high methane concentration in the early stage of growth.
通过上述方法制备的图案化金刚石电极,具有规则的微结构,电极的比表面积大,电极的响应电流大幅增加。The patterned diamond electrode prepared by the above method has a regular microstructure, the specific surface area of the electrode is large, and the response current of the electrode is greatly increased.
本发明的实施方式Embodiments of the present invention
通过以下实施例进一步阐明本发明的实质性特点和显著进步,但本发明绝非仅局限于实施例。The following examples further illustrate the substantive features and significant progress of the present invention, but the present invention is by no means limited to the examples.
实施例 1。
Example 1 .
步骤1、不锈钢薄片图案化。方法为,使用光刻设备在不锈钢片上依据所需的正方形阵列图形,刻蚀出对应图形的通孔图案,获得中间隔层。Step 1. Pattern the stainless steel sheet. The method is to etch the through hole pattern corresponding to the pattern on the stainless steel sheet according to the required square array pattern using a photolithography device to obtain the intermediate spacer layer.
步骤2、热丝化学气相沉积基台设计。方法为,根据检测电极所需的实际尺寸2cm
2,设计化学气相沉积的基台尺寸为4 cm
2,富余尺寸为固定时所需的余量尺寸,使用耐高温的钼金属线切割成相应尺寸的基台配件并完成组装。
Step 2. Design of hot wire chemical vapor deposition abutment. The method is, according to the actual size of the detection electrode 2cm 2 , the design of the chemical vapor deposition base size is 4 cm 2 , the margin size is the margin size required when fixing, and the high temperature resistant molybdenum wire is used to cut into the corresponding size Abutment accessories and complete assembly.
步骤3、化学气相法在硅片衬底上沉积掺硼金刚石膜。方法为,将步骤1中制备得的图案薄片和硅片衬底放置于丙酮溶液中,超声清洗10分钟,去除表面油渍;然后在去离子水中超声清洗5分钟,烘干炉中吹干后放入化学气相沉积室中,采用5 ℃/min速度将硅片衬底表面的温度升至750℃,进行掺硼金刚石膜的生长。Step 3. Depositing a boron-doped diamond film on the silicon wafer substrate by a chemical vapor method. The method is to place the pattern sheet and silicon wafer substrate prepared in step 1 in an acetone solution, and ultrasonically clean for 10 minutes to remove oil stains on the surface; then ultrasonically clean in deionized water for 5 minutes, and then dry it in a drying oven. Into the chemical vapor deposition chamber, the temperature of the surface of the silicon wafer substrate was raised to 750°C at a speed of 5°C/min, and the boron-doped diamond film was grown.
生长过程中的热丝匝数为10匝,热丝温度控制在2100℃,控制腔压约2.5千帕;先控制通入气体的质量流量为甲烷20sccm,硼烷0.3 sccm ,氢气为49 sccm;生长1h. 然后,硼烷与,氢气的通入量不变,调节甲烷的通入量为5 sccm生长6 h,最终获得掺硼金刚石膜的厚度为5-10µm,生长的金刚石膜晶粒大小在5-7微米。During the growth process, the number of turns of the hot wire is 10 turns, the temperature of the hot wire is controlled at 2100°C, and the cavity pressure is controlled to be about 2.5 kPa; first control the mass flow of methane 20 sccm, borane 0.3 sccm, and hydrogen 49 sccm; Grow for 1h. Then, the amount of borane and hydrogen introduced does not change, adjust the amount of methane introduced to 5 sccm and grow for 6 hours. Finally, the thickness of the boron-doped diamond film is 5-10µm, and the grain size of the grown diamond film At 5-7 microns.
步骤4、将步骤3所得图案化金刚石电极封装,铂片作为对电极, Ag/AgCl电极作为参比电极一起构成三电极检测传感器。Step 4. The patterned diamond electrode obtained in step 3 is packaged, the platinum sheet is used as the counter electrode, and the Ag/AgCl electrode is used as the reference electrode to form a three-electrode detection sensor.
步骤5、使用步骤4所制备的电极对多巴胺溶液进行检测。该图案化电极与非多孔电极相比,有效活性面积更大(图案化电极面积为0.25 cm
2,非图案化电极为0.14 cm
2,指标实验为2 mM 的铁氰化钾溶液,扫描速度为10mV/s),电荷转移电阻更小(图案化电极为4.5 Ω,非图案化电极10.5Ω,指标实验为电化学阻抗测试,具体在2 mM 的铁氰化钾溶液中,测试频率1 Hz-1MHz,开路电压为10 mV)。检测对象为浓度范围在0.01-500µM的多巴胺溶液,干扰对象为500µM
的抗坏血酸溶液,两类溶液的底液均采用0.01
M 的磷酸盐PBS溶液。将干扰物分别加入不同浓度的多巴胺溶液当中,使用封装后的电极进行检测分析,检测分析过程采用循环伏安法(扫描速度为20 mV每秒)和方波伏安法(脉冲幅值为30 mV,频率采用5赫兹)。检测结果显示:该电极对于多巴胺的检测限位60 nM. 检测线性范围达到5-50µM。
Step 5. Use the electrode prepared in step 4 to detect the dopamine solution. Compared with the non-porous electrode, the patterned electrode has a larger effective active area (the area of the patterned electrode is 0.25 cm 2 , the non-patterned electrode is 0.14 cm 2 , the index experiment is 2 mM potassium ferricyanide solution, and the scanning speed is 10mV/s), the charge transfer resistance is smaller (4.5 Ω for patterned electrodes, 10.5 Ω for non-patterned electrodes, the index experiment is electrochemical impedance test, specifically in 2 mM potassium ferricyanide solution, the test frequency is 1 Hz- 1MHz, open circuit voltage is 10 mV). The detection object is a dopamine solution with a concentration range of 0.01-500μM, and the interference object is a 500μM ascorbic acid solution. Both types of solutions use 0.01 M phosphate PBS solution as the substrate. Interfering substances were added to dopamine solutions of different concentrations, and the encapsulated electrodes were used for detection and analysis. The detection and analysis process used cyclic voltammetry (scanning speed of 20 mV per second) and square wave voltammetry (pulse amplitude of 30). mV, the frequency is 5 Hz). The test results show that the detection limit of the electrode for dopamine is 60 nM. The detection linear range is 5-50µM.
实施例 2。
Example 2 .
步骤1、不锈钢薄片图案化。方法为,使用光刻设备在不锈钢片上依据所需的正方形阵列图形、长方形阵列图形、圆形阵列图形等刻蚀出对应图形的通孔图案,获得中间隔层。Step 1. Pattern the stainless steel sheet. The method is to use a photoetching equipment to etch the through hole pattern corresponding to the pattern on the stainless steel sheet according to the required square array pattern, rectangular array pattern, circular array pattern, etc., to obtain the intermediate spacer layer.
步骤2、热丝化学气相沉积基台设计。方法为,根据检测电极所需的实际尺寸4cm
2,设计化学气相沉积的基台尺寸为8 cm
2,富余尺寸为固定时所需的余量尺寸,使用耐高温的钼金属线切割成相应尺寸的基台配件并完成组装。
Step 2. Design of hot wire chemical vapor deposition abutment. The method is, according to the actual size of the detection electrode 4cm 2 , the design of the chemical vapor deposition base size is 8 cm 2 , the margin size is the margin size required when fixing, and the high temperature resistant molybdenum wire is used to cut into the corresponding size Abutment accessories and complete assembly.
步骤3、化学气相法在硅片衬底上沉积掺硼金刚石膜。方法为,将步骤1中制备得的图案薄片和硅片衬底放置于丙酮溶液中,超声清洗15分钟,去除表面油渍;然后在去离子水中超声清洗10分钟,烘干炉中吹干后放入化学气相沉积室中,采用10 ℃/min速度将硅片衬底表面的温度升至850℃,进行掺硼金刚石膜的生长。Step 3. Depositing a boron-doped diamond film on the silicon wafer substrate by a chemical vapor method. The method is to place the pattern sheet and silicon wafer substrate prepared in step 1 in an acetone solution, and ultrasonically clean for 15 minutes to remove oil stains on the surface; then ultrasonically clean in deionized water for 10 minutes, and then dry it in a drying oven. Into the chemical vapor deposition chamber, the temperature of the surface of the silicon wafer substrate was increased to 850°C at a speed of 10°C/min, and the boron-doped diamond film was grown.
生长过程中的热丝匝数为13匝,热丝温度控制在2300 ℃,控制腔压约4千帕;先控制通入气体的质量流量为甲烷15sccm,硼烷0.5 sccm ,氢气为47 sccm;生长1.5h.然后,硼烷与,氢气的通入量不变,调节甲烷的通入量为3 sccm,生长8 h,最终获得掺硼金刚石膜的厚度为10-15µm,生长的金刚石膜晶粒大小在7-9微米。During the growth process, the number of turns of the hot wire is 13 turns, the temperature of the hot wire is controlled at 2300 ℃, and the cavity pressure is about 4 kPa; the mass flow of the gas is controlled to 15 sccm for methane, 0.5 sccm for borane, and 47 sccm for hydrogen; Growing for 1.5h. Then, the amount of borane and hydrogen introduced is unchanged, and the amount of methane introduced is adjusted to 3 sccm, and grown for 8 hours. Finally, the thickness of the boron-doped diamond film is 10-15 µm, and the grown diamond film crystal The particle size is 7-9 microns.
步骤4、将步骤3所得图案化金刚石电极封装,铂片作为对电极, Ag/AgCl电极作为参比电极一起构成三电极检测传感器。Step 4. The patterned diamond electrode obtained in step 3 is packaged, the platinum sheet is used as the counter electrode, and the Ag/AgCl electrode is used as the reference electrode to form a three-electrode detection sensor.
步骤5、使用步骤4所制备的电极对多巴胺溶液进行检测。该图案化电极与非多孔电极相比,有效活性面积更大(图案化电极面积为0.3 cm
2,非图案化电极为0.23 cm
2,指标实验为2 mM 的铁氰化钾溶液,扫描速度为10mV/s),电荷转移电阻更小(图案化电极为5.0Ω,非图案化电极14.0Ω,指标实验为电化学阻抗测试,具体在2 mM 的铁氰化钾溶液中,测试频率1 Hz-1MHz,开路电压为10 mV)。检测对象为浓度范围在0.01-500µM的多巴胺溶液,干扰对象为1000µM
的抗坏血酸溶液,两类溶液的底液均采用0.01
M 的磷酸盐PBS溶液。将干扰物分别加入不同浓度的多巴胺溶液当中,使用封装后的电极进行检测分析,检测分析过程采用循环伏安法(扫描速度为20 mV每秒)和方波伏安法(脉冲幅值为30 mV,频率采用5赫兹)。检测结果显示:该电极对于多巴胺的检测限位50 nM. 检测线性范围达到1-80µM。
Step 5. Use the electrode prepared in step 4 to detect the dopamine solution. Compared with the non-porous electrode, the patterned electrode has a larger effective active area (the area of the patterned electrode is 0.3 cm 2 , the non-patterned electrode is 0.23 cm 2 , the index experiment is 2 mM potassium ferricyanide solution, and the scanning speed is 10mV/s), the charge transfer resistance is smaller (5.0Ω for patterned electrodes and 14.0Ω for non-patterned electrodes. The index experiment is electrochemical impedance test, specifically in 2 mM potassium ferricyanide solution, the test frequency is 1 Hz- 1MHz, open circuit voltage is 10 mV). The detection object is a dopamine solution with a concentration range of 0.01-500μM, and the interference object is a 1000μM ascorbic acid solution. The substrates of the two types of solutions are 0.01 M phosphate PBS solution. Interfering substances were added to dopamine solutions of different concentrations, and the encapsulated electrodes were used for detection and analysis. The detection and analysis process used cyclic voltammetry (scanning speed of 20 mV per second) and square wave voltammetry (pulse amplitude of 30). mV, the frequency is 5 Hz). The test results show that the detection limit of the electrode for dopamine is 50 nM. The detection linear range is 1-80 µM.
实施例 3。
Example 3 .
步骤1、不锈钢薄片图案化。方法为,使用光刻设备在不锈钢片上依据所需的正方形阵列图形、长方形阵列图形、圆形阵列图形等刻蚀出对应图形的通孔图案,获得中间隔层。Step 1. Pattern the stainless steel sheet. The method is to use a photolithography device to etch the through hole pattern corresponding to the pattern on the stainless steel sheet according to the required square array pattern, rectangular array pattern, circular array pattern, etc., to obtain the intermediate spacer layer.
步骤2、热丝化学气相沉积基台设计。方法为,根据检测电极所需的实际尺寸10 cm
2,设计化学气相沉积的基台尺寸为15 cm
2,富余尺寸为固定时所需的余量尺寸,使用耐高温的钼金属线切割成相应尺寸的基台配件并完成组装。
Step 2. Design of hot wire chemical vapor deposition abutment. The method is, according to the actual size of the detection electrode 10 cm 2 , the design of the chemical vapor deposition abutment size is 15 cm 2 , the margin size is the margin size required when fixing, and the high temperature resistant molybdenum wire is used to cut into the corresponding The size of the abutment accessories and complete the assembly.
步骤3、化学气相法在硅片衬底上沉积掺硼金刚石膜。方法为,将步骤1中制备得的图案薄片和硅片衬底放置于丙酮溶液中,超声清洗20分钟,去除表面油渍;然后在去离子水中超声清洗20分钟,烘干炉中吹干后放入化学气相沉积室中,采用15 ℃/min速度将硅片衬底表面的温度升至950℃,进行掺硼金刚石膜的生长,生长过程中的热丝匝数为15匝,热丝温度控制在2400 ℃,腔压约5千帕,先控制通入气体的质量流量为甲烷10 sccm,硼烷1 sccm ,氢气为45 sccm;生长2h.然后,硼烷与,氢气的通入量不变,调节甲烷的通入量为2 sccm,生长10 h,最终获得掺硼金刚石膜的厚度为15-20µm,生长的金刚石膜晶粒大小在9-10微米直径。Step 3. Depositing a boron-doped diamond film on the silicon wafer substrate by a chemical vapor method. The method is to place the pattern sheet and silicon wafer substrate prepared in step 1 in an acetone solution, and ultrasonically clean for 20 minutes to remove oil stains on the surface; then ultrasonically clean in deionized water for 20 minutes, and then dry it in a drying oven. Into the chemical vapor deposition chamber, the temperature of the silicon wafer substrate surface is increased to 950℃ at a speed of 15 ℃/min, and the boron-doped diamond film is grown. The number of turns of the hot wire during the growth process is 15 turns, and the temperature of the hot wire is controlled. At 2400 ℃, the chamber pressure is about 5 kPa, first control the mass flow of the gas to be 10 sccm of methane, 1 sccm of borane, and 45 sccm of hydrogen; grow for 2 hours. Then, the amount of borane and hydrogen introduced does not change. , Adjust the input of methane to 2 sccm, grow for 10 hours, and finally obtain a boron-doped diamond film with a thickness of 15-20 µm, and the grown diamond film has a grain size of 9-10 microns in diameter.
步骤4、将步骤3所得图案化金刚石电极封装,铂片作为对电极, Ag/AgCl电极作为参比电极一起构成三电极检测传感器。Step 4. The patterned diamond electrode obtained in step 3 is packaged, the platinum sheet is used as the counter electrode, and the Ag/AgCl electrode is used as the reference electrode to form a three-electrode detection sensor.
步骤5、使用步骤4所制备的电极对多巴胺溶液进行检测。该图案化电极与非多孔电极相比,有效活性面积更大(图案化电极面积为0.35 cm
2,非图案化电极为0.27 cm
2,指标实验为2 mM 的铁氰化钾溶液,扫描速度为10mV/s),电荷转移电阻更小(图案化电极为6.0Ω,非图案化电极16.0Ω,指标实验为电化学阻抗测试,具体在2 mM 的铁氰化钾溶液中,测试频率1 Hz-1MHz,开路电压为10 mV)。检测对象为浓度范围在0.01-500µM的多巴胺溶液,干扰对象为1500µM
的抗坏血酸溶液,两类溶液的底液均采用0.01
M 的磷酸盐PBS溶液。将干扰物分别加入不同浓度的多巴胺溶液当中,使用封装后的电极进行检测分析,检测分析过程采用循环伏安法(扫描速度为20 mV每秒)和方波伏安法(脉冲幅值为30 mV,频率采用5赫兹)。检测结果显示:该电极对于多巴胺的检测限位45 nM. 检测线性范围达到0.5-100 µM。
Step 5. Use the electrode prepared in step 4 to detect the dopamine solution. Compared with the non-porous electrode, the patterned electrode has a larger effective active area (the area of the patterned electrode is 0.35 cm 2 , the non-patterned electrode is 0.27 cm 2 , the index experiment is 2 mM potassium ferricyanide solution, and the scanning speed is 10mV/s), the charge transfer resistance is smaller (the patterned electrode is 6.0Ω, the non-patterned electrode is 16.0Ω, the index experiment is electrochemical impedance test, specifically in the 2 mM potassium ferricyanide solution, the test frequency is 1 Hz- 1MHz, open circuit voltage is 10 mV). The detection object is a dopamine solution with a concentration range of 0.01-500μM, and the interference object is a 1500μM ascorbic acid solution. Both types of solutions use 0.01 M phosphate PBS solution as the substrate. Interfering substances were added to dopamine solutions of different concentrations, and the encapsulated electrodes were used for detection and analysis. The detection and analysis process used cyclic voltammetry (scanning speed of 20 mV per second) and square wave voltammetry (pulse amplitude of 30). mV, the frequency is 5 Hz). The test results show that the detection limit of the electrode for dopamine is 45 nM. The detection linear range is 0.5-100 µM.
对比例1。Comparative example 1.
该对比例1其他条件与实施例1相同,仅在步骤3中对图案薄片和硅片衬底不进行四周限位固定,结果不能生长出与图案相一致的金刚石阵列。原因在于硅基底与不锈钢图案薄片间本身热膨胀系数相差较大,如果限位不好,很容易产生变形和移位等现象,导致金刚石膜生长失败。The other conditions of this comparative example 1 are the same as those of the embodiment 1, except that the pattern sheet and the silicon wafer substrate are not fixed around the periphery in step 3, and as a result, a diamond array consistent with the pattern cannot be grown. The reason is that the thermal expansion coefficient of the silicon substrate and the stainless steel pattern sheet is quite different. If the limit is not good, it is easy to deform and shift and cause the growth of the diamond film to fail.
对比例2。Comparative example 2.
该对比例2其他条件均与实施例1相同,仅在步骤3中甲烷初始的气流量为8 sccm,,结果不能生长出与图案相一致的金刚石阵列。原因在于硅基底与不锈钢图案薄片间本身留给碳原子形核的区域就较小,如果碳原子浓度不够,很难再较小的区域内形核、生长,最终成膜,导致金刚石膜生长失败。The other conditions of this comparative example 2 are the same as those of embodiment 1, except that the initial gas flow rate of methane in step 3 is 8 sccm, and as a result, a diamond array consistent with the pattern cannot be grown. The reason is that the area between the silicon substrate and the stainless steel pattern sheet itself left for the nucleation of carbon atoms is relatively small. If the concentration of carbon atoms is not enough, it is difficult to nucleate and grow in a smaller area, and finally form a film, which leads to the failure of diamond film growth. .
对比例3。Comparative example 3.
该对比例3其他条件与实施例1相同,仅在步骤3中热丝温度调为1800℃,结果不能生长出金刚石阵列。原因在于热丝温度过低,导致不能有效裂解足够多的碳原子进行金刚石的生长,另外热丝温度过低,也会影响基底温度,导致碳原子的形核受阻,进一步阻止了碳原子的成膜过程。The other conditions of this comparative example 3 are the same as those of example 1, except that in step 3, the temperature of the hot wire is adjusted to 1800°C. As a result, a diamond array cannot be grown. The reason is that the temperature of the hot wire is too low, which prevents the effective cracking of enough carbon atoms for diamond growth. In addition, the temperature of the hot wire is too low, which will also affect the substrate temperature, causing the nucleation of carbon atoms to be hindered, and further preventing the formation of carbon atoms. Membrane process.
对比例4。Comparative example 4.
该对比例3其他条件与实施例1相同,仅是采用30℃/min速度将硅片衬底表面的温度升至750℃。结果发现并不能有效形核,最终未能生长出金刚石膜。原因在于该升温速率较本专利提出的升温速率来说存在过快的问题,前面提出的基底和掩模之间的热膨胀系数相差巨大,如果升温过快,会导致热变形严重,升温初期与升温后期图案化区域出现了很明显的移位现象,致使碳原子不能在同一区域有效形核,最终生长失败。The other conditions of this comparative example 3 are the same as those of embodiment 1, except that the temperature of the surface of the silicon wafer substrate is increased to 750°C at a speed of 30°C/min. As a result, it was found that the nucleation was not effective, and the diamond film could not be grown in the end. The reason is that the heating rate is too fast compared to the heating rate proposed in this patent. The thermal expansion coefficient between the substrate and the mask proposed earlier is very different. If the heating is too fast, it will cause serious thermal deformation. In the later patterning area, there was a very obvious displacement phenomenon, so that the carbon atoms could not effectively nucleate in the same area, and finally the growth failed.
对比例5。Comparative Example 5.
该对比例5其他条件与实施例3相同,仅是步骤3中初始采用的甲烷流量为30 sccm。结果发现并不能在基底上有效形核,最终生长金刚石膜失败。原因为使用的初始甲烷浓度过高,过多裂解的碳原子堆积在生长区域内,但裂解的原子氢不能及时地把过量的碳原子带走,而过量的碳原子就会形成石墨相,造成金刚石膜生长停滞,最终导致生长区域内观察到较多的石墨相,而金刚石膜生长失败。The other conditions of this comparative example 5 are the same as those of example 3, except that the methane flow rate initially adopted in step 3 is 30 sccm. It turns out that the nucleation cannot be effectively formed on the substrate, and the growth of the diamond film fails. The reason is that the initial methane concentration used is too high. The excessively cracked carbon atoms are accumulated in the growth area, but the cracked atomic hydrogen cannot take away the excessive carbon atoms in time, and the excessive carbon atoms will form a graphite phase, resulting in The growth of the diamond film is stagnant, which eventually leads to more graphite phases observed in the growth area, and the growth of the diamond film fails.